Abstract

Cancer vaccines based on tumor cell components have shown promising results in animal and clinical studies. The vaccine system contains abundant tumor antigen components, which can activate the immune system by antigens. However, their efficacy has been limited by the inability of antigens delivery, which are the core components of vaccines, further fail to be presented and activation of effective cells. Nanotechnology offers a novel platform to enhance the immunogenicity of tumor-associated antigens and deliver them to antigen-presenting cells (APCs) more efficiently. In addition, nanotreatment of tumor cells derivate active ingredients could also help improve the effectiveness of cancer vaccines. In this review, we summarize recent advances in the development of cancer vaccines by the combination of nanotechnology and tumor-based ingredients, including liposomes, polymeric nanoparticles, metallic nanoparticles, virus-like particles and tumor cells membrane, tumor lysate, and specific tumor antigens. These nanovaccines have been designed to increase antigen uptake, prolong antigen presentation, and modulate immune responses through codelivery of immunostimulatory agents. We also further discuss challenges and opportunities in the clinical translation of these nanovaccines.

Introduction

Cancer immunotherapy has revolutionized cancer treatment by harnessing the immune system to recognize and attack cancer cells [1–3]. Among various immunotherapeutic approaches, cancer vaccines have attracted significant attention due to their potential to induce long-lasting and specific immune responses against tumor cells [4–7]. By comparison with surgery, it hardly produce large wounds, nor does it cause higher toxicity in normal tissues and drug tolerance like chemotherapy in the treatment of tumor. However, the clinical efficacy of cancer vaccines based on tumor cell components, such as peptides and proteins, is limited by their poor immunogenicity and inefficient delivery to antigen presentation cells (APCs). Although, many cancer vaccines were applied with the immune-stimulatory agents, such as the programmed cell death protein 1 (PD-1), CpG oligonucleotide, etc. The clinical response rates remain low, especially in the hypoimmunogenic tumors. As we all know, pancreatic cancer is a more difficult type for immunotherapy as a low immunogenic tumor. Therefore, there are few effective cancer vaccines that can actively promote the pancreatic cancer treatment. Meanwhile, limited by the specific tumor antigens, the development of cancer vaccines was extremely difficult.

The field of cancer vaccines has seen significant advancements in recent years, with numerous studies focusing on different aspects of vaccine development and application [8–12]. These advances have been facilitated by the exploration of various types of cancer vaccines, including those targeting viral antigens, neoantigens, and other tumor-specific antigens [13–16]. One approach in cancer vaccine research involves targeting shared antigens from viral infections linked to certain cancer types, such as Epstein–Barr virus and HPV. Studies have shown promising results with vaccines targeting viral antigens like Epstein–Barr nuclear antigen 1 and latent membrane proteins, as well as HPV-related antigens, demonstrating favorable antitumor efficacy and the potential to establish durable T cell memory in rapidly progressing HPV-positive tumors [17]. Another significant area of research is neoantigen cancer vaccines. Neoantigens, derived from nonsynonymous cell variants, are only expressed in tumor cells and can bypass thymus-negative selection, leading to robust neoantigen-specific T cell responses [14]. Advances in genomic and transcriptional profiling have made identifying putative neoantigens possible, although challenges remain in predicting which neoantigens can effectively induce neoantigen-specific T cell responses [18–20]. Cancer vaccines are being developed to stimulate antitumor immunity with tumor antigens delivered in various forms, such as cells, peptides, viruses, and nucleic acids [21–24]. These vaccines aim to overcome tumor heterogeneity and reverse the immunosuppressive microenvironment. Challenges in the field include single antigen targeting, weak immunogenicity, off-target effects, and impaired immune response [25–27]. Current research and reviews provide insights into the principle of action, components, classification, delivery methods, and progress of cancer vaccines, offering a broader perspective for future vaccine design.

Recent studies have shown that tumor antigens can be used for the design of cancer vaccines without the necessity to identify, parse, and reconstruct certain antigens [28–31]. A novel concept has been proposed that the whole antigen vaccine systems derived from tumor cells could be designed to conquer cancer treatments [32–34]. The tumor cells themselves are a huge antigen pool with countless tumor antigen epitopes, which can be used to activate antitumor immune response. Among them, more studies have focused on the application of tumor cell membrane as tumor antigens to stimulate APCs and further activate the antitumor immune response of T cells. In addition, the activation of T cells in immune response requires the involvement of costimulatory molecules. Some studies are based on this theoretical foundation, using genetic engineering to modify tumor cell membranes. By retaining antigen on the cell membrane and inducing the expression of costimulatory molecule CD80, T cells can be directly activated, thereby achieving antitumor immune response [35] (Figure 1). Of course, many studies combine tumor cell membranes that retain tumor antigens with other functional molecules to directly activate dendritic cells (DCs) for antigen presentation, leading to the activation of T cell immune response. These are two different approaches aimed at achieving the same goal [36–38]. A series of nanovaccines developed on this basis have been widely used in the treatment of different tumor cells and preclinical experiments.

Abstract

Bacteria extracellular vesicles (BEVs), characterized as the lipid bilayer membrane-surrounded nanoparticles filled with molecular cargo from parent cells, play fundamental roles in the bacteria growth and pathogenesis, as well as facilitating essential interaction between bacteria and host systems. Notably, benefiting from their unique biological functions, BEVs hold great promise as novel nanopharmaceuticals for diverse biomedical potential, attracting significant interest from both industry and academia. Typically, BEVs are evaluated as promising drug delivery platforms, on account of their intrinsic cell-targeting capability, ease of versatile cargo engineering, and capability to penetrate physiological barriers. Moreover, attributing to considerable intrinsic immunogenicity, BEVs are able to interact with the host immune system to boost immunotherapy as the novel nanovaccine against a wide range of diseases. Towards these significant directions, in this review, we elucidate the nature of BEVs and their role in activating host immune response for a better understanding of BEV-based nanopharmaceuticals’ development. Additionally, we also systematically summarize recent advances in BEVs for achieving the target delivery of genetic material, therapeutic agents, and functional materials. Furthermore, vaccination strategies using BEVs are carefully covered, illustrating their flexible therapeutic potential in combating bacterial infections, viral infections, and cancer. Finally, the current hurdles and further outlook of these BEV-based nanopharmaceuticals will also be provided.

Introduction

Vesiculation is a crucial and fundamental process across all kinds of species to produce the extracellular vesicles that serve as essential mediators of basic physiological events [1]. These nanovesicles are filled with molecular patterns originated from parent cells, including metabolites, nucleic acids, proteins, and signaling molecules, to maintain cell growth and homeostasis [2, 3]. Biological regulation by extracellular vesicles is widespread across both prokaryotes and eukaryotes [4]. Notably, bacteria, as one of the major inhabitants in the human body, establish intricate relationships with host health and disease, wherein bacterial extracellular vesicles (BEVs) are indispensably involved in these processes [5, 6]. With the increasing and deep understanding of their biological function, BEVs are found to influence various cellular behaviors, including the transport of genetic information, phage infection, mediation of metabolism, as well as interaction between bacteria-bacteria and bacteria-host [7, 8].

Particularly, BEVs are characterized as nanosized nanoparticles, surrounded by lipid-bilayer membranes, ranging from 20 to 400 nm in diameter [7]. In account of the diversity of bacterial types and biogenesis mechanisms, the BEVs could carry versatile cargos inherited from mother cells, such as lipopolysaccharides (LPS), endotoxins, genetic information, cytosolic and membrane proteins [9]. By thanking the unique structure and intrinsic properties of BEVs, these naturally occurring nanovesicles attract the research interest to be developed as novel nanopharmaceuticals, prompting further exploration of their biomedical applications [10, 11]. Generally, BEVs are widely evaluated as biotherapeutics in different forms. Firstly, these nanovesicles with hollow structures could serve as novel drug delivery platforms, facilitating the transport of diverse bioactive molecules and therapeutic cargo to the recipient cells at the lesion site [12]. Thanks to the stability of naturally-occurring membrane structure, the BEVs-based drug delivery platform could carry the therapeutic genetic tools (e.g. siRNA, CRISPR-Cas9, etc.), protecting them from enzymatic degradation or hydrolysis in the complex physiological environment [13, 14]. Besides, benefiting from the ease of modification, BEVs-based drug delivery platforms could efficiently load the small molecular therapeutics [14], or directly produce the synthetic cargo (e.g. antigens, enzymes, therapeutic proteins, etc.) on the BEVs by editing the desired gene in parent bacteria. The BEVs-based drug carriers are also featured in their capability for targeting delivery toward the disease area to enhance drug accumulation and availability [15]. Moreover, the BEVs drug delivery platform can integrate with functional materials, to facilitate combinational therapy (e.g. photodynamic therapy, photothermal therapy, etc.) and maximize the synergistic therapeutic efficiency [16].

Conclusion and further perspective

In this review, we comprehensively summarize the development of BEV-based nanopharmaceuticals to facilitate disparate biomedical applications in recent years. Amongst the unique advantages and functions of BEVs, we demonstrated the tremendous potential of applying these naturally occurring nanovesicles to establish a myriad of innovative therapeutic strategies for new-generation pharmaceuticals evolution, especially in the versatile bioactive cargo delivery and powerful vaccination approaches.

Taking the unique merits of nanovesicles, the structural stability, ease of cargo loading, promising penetration across physiological barriers, and specific targeting capabilities endow the BEVs application to be beneficial in delivery for a wide range of therapeutics. Particularly, the naturally occurring membrane structure of BEVs enables targeting delivery of therapeutic genetic tools (e.g., siRNA, DNA, CRISPR-Cas9, etc.) in the physiological, preserving stability and bioactivity, thus enhancing gene therapy. Leveraging the ease of genetic modification in parent bacteria, protein cargo, such as enzymes and antigens, can also be directly expressed within BEVs, optimizing loading efficiency compared to conventional delivery platforms. Furthermore, advancements in nanotechnology and material science have witnessed the integration of functional materials with BEV delivery platforms to achieve combinational therapy, thereby further improving the synergistic therapeutic efficacy.

Introduction

Tumor microenvironment (TME) is a complex network of cancer cells and various other cellular and noncellular components. Microorganisms such as bacteria, viruses, fungi, phages, and protozoa naturally occur in the TME, modulating the metabolic composition and promoting or inhibiting tumorigenesis. In the last decades, a growing interest has emerged in microorganisms in the TME and their potential applications for cancer therapy 1, 2.

Bacterial and viral infections have been long associated with cancer development and have been used in cancer therapy decades ago. Bacteria have various effects on cancer cells through different modes of action, for instance, depending on the strain, tissue, and environment 1, 2. Viruses also naturally occur in the TME, and some strains promote cancer growth, such as the human papillomavirus (HPV) [3], while others have oncolytic activity, such as the influenza A virus (IAV) [4]. The different mechanisms through which bacteria and viruses affect tumor proliferation and metastasis include altering immune responses 5, 6, 7•, secreting cytotoxic molecules such as formate or colibactine 8••, 9, and alterations of metabolic and signaling pathways 8••, 10. The natural abilities of microorganisms to colonize and alter the TME can also be used for cancer detection and therapy with the help of engineered bacteria and viruses 2, 11, 12. However, the metabolic interactions among viruses, bacteria, cancer cells, and TME are not well understood. Metabolites function as signaling molecules, and we are just beginning to understand the functional role of small molecules within the TME 13, 14, 15. For instance, the immunometabolite itaconate has antimicrobial properties but may also affect tumor progression by altering cancer cell metabolism or the composition of the TME 16, 17•, 18, 19. Thus, further research is needed to identify the key players within the TME that affect immune responses and tumor progression.

Approaches in virotherapy

Virotherapy aims to transform the ‘cold’ immunosuppressive TME, characterized by high levels of TAMs, T-regulatory cells (Tregs), MDSCs, and activated M2-like macrophages, into a ‘hot’ immunoreactive TME (Figure 3). This transformation involves the recruitment of, for instance, NKs, DCs, and M1-like macrophages (Figure 3). OV administration targets different approaches in cancer therapies, such as making the virus dependent on specific genes within the cancer host cell to enable selective replication in malignant cells, followed by direct lysis. Furthermore, it is applied to deliver specific antibodies to inhibit tumor growth [45]. For instance, the recombinant human type-5 adenovirus (Ad5) selectively replicates in tumor cells with p53-defective influencing cancer cell growth [46]. OVs may also indirectly affect the TME and tumor growth by inducing the release of cytokines, such as interferon (IFN), damage-associated molecular patterns (DAMPs), high mobility group box 1 protein (HMGB1), or pathogen-associated molecular patterns (PAMPs) 41, 47, leading to further recruiting and activation of the innate and adaptive immune system, including DCs (Figure 3). DCs play an elementary role in connecting both immune systems and are infrequently present in the cold TME. These findings highlight various targets that can be used to modulate the immune response in the TME through OVs, aiming to constrain tumor growth and increase patient outcomes.

Conclusion

Bacterial and viral infections play a vital role in altering the composition of the TME, thus influencing its potential as pro- or anti-tumorigenic. Many bacteria and viruses influence TME, for instance, by secreting signal molecules, altering specific immune responses, causing DNA damage, or inducing metabolic rewiring. While promising approaches utilizing bacteria and viruses for cancer detection and therapy exist, how infections influence metabolism to promote either pro- or antitumor properties is still not well understood. Engineered bacteria and viruses could be optimized to work effectively against cancer with potentially less off-target effects compared with conventional therapies. For example, altering levels of cytokines or metabolites such as itaconate or arginine in the TME may promote an anticancer immune response, either alone or in combination with existing treatments. Expanding our current knowledge of the complex interaction of microorganisms and cancer cells will provide us with effective ways to develop new treatment strategies.

Abstract

Objective. Mesenchymal stem cell (MSC) therapy has been explored in Huntington disease (HD) as a potential therapeutic approach; however, a complete synthesis of these results is lacking. We conducted a meta-analysis to evaluate the effects of MSCs on HD. Method. Eligible studies published before November 2022 were screened from Embase, PubMed, Web of Science, Medline, and Cochrane in accordance with PRISMA guidelines. ClinicalTrial.gov and the World Health Organization International Clinical Trials Registry Platform were also searched for registered clinical trials. The outcomes in rodent studies evaluated included morphological changes (striatal volume and ventricular volume), motor function (rotarod test, wire hang test, grip strength test, limb-clasping test, apomorphine-induced rotation test, and neuromuscular electromyography activity), cognition (Morris water maze test), and body weight. Result. The initial search returned 362 records, of which 15 studies incorporating 346 HD rodents were eligible for meta-analysis. Larger striatal and smaller ventricular volumes were observed in MSC-treated animals compared to controls. MSCs transplanted before the occurrence of motor dysfunction rescued the motor incoordination of HD. Among different MSC sources, bone marrow mesenchymal stem cells were the most investigated cells and were effective in improving motor coordination. MSC therapy improved muscle strength, neuromuscular electromyography activity, cortex-related motor function, and striatum-related motor function, while cognition was not changed. The body weight of male HD rodents increased after MSC transplantation, while that of females was not affected. Conclusion. Meta-analysis showed a positive effect of MSCs on HD rodents overall, as reflected in morphological changes, motor coordination, muscle strength, neuromuscular electromyography activity, cortex-related motor function, and striatum-related motor function, while cognition was not changed by MSC therapy.

Introduction

Huntington disease (HD) is a neurodegenerative disorder of the central nervous system resulting from a dominantly inherited CAG trinucleotide repeat expansion in exon 1 of the huntingtin (HTT) gene that encodes the Huntingtin protein [1]. Pathological changes are characterized by a general shrinkage of the brain and distinct degeneration of the striatum (caudate nucleus and putamen) [2]. Although HD prevalence is only 4-10 individuals per 100,000, it seriously affects the life quality of the patients in many ways, including movement, cognition, and psychological condition, as well as other functional disabilities [3]. Motor defects typically include chorea and loss of coordination. Psychiatric symptoms, such as depression, psychosis, and obsessive-compulsive disorder, are common in HD [4]. Death typically occurs about 20 years after symptom onset [1].

Current therapies for HD are directed at symptom relief, as there are no any disease-modifying therapies. Therapeutic attempts based on pathogenic mechanisms including gene silencing [5], antiapoptosis/caspase inhibition [6], transglutaminase inhibition [7], antioxidative stress [8], upregulating autophagy [9], and physical exercise [10] have been investigated; unfortunately, none of these have met the criteria for clinical translation. For instance, silencing the expression of the mutant HTT gene is attractive; however, allele specificity and off-target effects are not fully resolved. Treatment of mouse models with antioxidants was considered to be beneficial [8], whereas trials of creatine for symptomatic patients were disappointing [11].

Conclusion

This meta-analysis reveals MSC therapy attenuates morphological changes and improves motor function in HD models, but cognition was not influenced. Furthermore, the weight of male, but not female, HD rodents may be benefited from MSC treatment. These results support MSC-based strategies becoming an alternative treatment for HD; however, before MSC therapies can be translated into clinical practice, their safety, efficacy, and mechanism must be established with more preclinical and clinical studies.

Abstract

Background

    Demonstrating that the data produced in metabolic phenotyping investigations (metabolomics/metabonomics) is of good quality is increasingly seen as a key factor in gaining acceptance for the results of such studies. The use of established quality control (QC) protocols, including appropriate QC samples, is an important and evolving aspect of this process. However, inadequate or incorrect reporting of the QA/QC procedures followed in the study may lead to misinterpretation or overemphasis of the findings and prevent future metanalysis of the body of work.

Objective

      The aim of this guidance is to provide researchers with a framework that encourages them to describe quality assessment and quality control procedures and outcomes in mass spectrometry and nuclear magnetic resonance spectroscopy-based methods in untargeted metabolomics, with a focus on reporting on QC samples in sufficient detail for them to be understood, trusted and replicated. There is no intent to be proscriptive with regard to analytical best practices; rather, guidance for reporting QA/QC procedures is suggested. A template that can be completed as studies progress to ensure that relevant data is collected, and further documents, are provided as on-line resources.

Key reporting practices

     Multiple topics should be considered when reporting QA/QC protocols and outcomes for metabolic phenotyping data. Coverage should include the role(s), sources, types, preparation and uses of the QC materials and samples generally employed in the generation of metabolomic data. Details such as sample matrices and sample preparation, the use of test mixtures and system suitability tests, blanks and technique-specific factors are considered and methods for reporting are discussed, including the importance of reporting the acceptance criteria for the QCs. To this end, the reporting of the QC samples and results are considered at two levels of detail: “minimal” and “best reporting practice” levels.

Introduction

     Progress in science is based on the principle that measurements are repeatable; that is to say, it should be possible for scientists in other laboratories, equipped with the same, or similar expertise, resources and infrastructure, to replicate the results of published work within acceptable levels of confidence. Properly documented studies allow other scientists to critically assess and judge the original experimental design and should also enable researchers in other laboratories to repeat the experiment under the same conditions and support or refute the findings. However, a reproducibility crisis in science has been recently highlighted by Munafò et al. (2017) and the lack of transparency in reporting can lead to ambiguity within experimental design, data collection, as well as data processing and interpretation, a situation which is also true for metabolomics. Moreover, any metabolomic data derived from instrumental analyses must be sufficiently reliable that decisions based on it can be reported with confidence; there should be no “leap of faith” from data to knowledge. If the metabolomic data cannot be trusted, then the answer to the posed question is of little value.

Discussion and conclusions

     The use of both QA and QC procedures is recognized as fundamental for achieving reliable and consistent data in metabolomics. The recommendations presented here are not meant to constrain research but to ensure that, where these systems have been employed, this is stated and what has been done is clearly explained. In this opinion paper there is no official authority to mandate the procedures that must be used when employing QA/QC in untargeted metabolomics. However, the recommendation here is that authors state what they did, and to state this as transparently and as completely as possible. In other words, they should deliberately and purposefully avoid obfuscation. The documentation of the QA and QC of the analytical process of an untargeted metabolomics experiment enables experimenters to demonstrate that the work was conducted appropriately, and that the editors and reviewers, and therefore ultimately readers can have confidence in the resulting conclusions. However, recognizing that untargeted metabolic phenotyping is a discovery methodology any hypotheses emerging from it are inevitably provisional. Nevertheless, armed with knowledge that the data are of good quality provides the motivation to devote the resources required to undertake further targeted analysis, using quantitative and validated methods, to confirm, or refute, these hypotheses.

Abstract

Introduction

To control or not to control?—That is the question

State-of-the-art phenotyping

Automated digital trait assessment

Transferability of collected data to agricultural practice is critical

Data management is key to knowledge discovery and innovation in breeding

Summary

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Abstract

Rising temperatures and changing precipitation patterns will affect agricultural production substantially, exposing crops to extended and more intense periods of stress. Therefore, breeding of varieties adapted to the constantly changing conditions is pivotal to enable a quantitatively and qualitatively adequate crop production despite the negative effects of climate change. As it is not yet possible to select for adaptation to future climate scenarios in the field, simulations of future conditions in controlled-environment (CE) phenotyping facilities contribute to the understanding of the plant response to special stress conditions and help breeders to select ideal genotypes which cope with future conditions. CE phenotyping facilities enable the collection of traits that are not easy to measure under field conditions and the assessment of a plant‘s phenotype under repeatable, clearly defined environmental conditions using automated, non-invasive, high-throughput methods. However, extrapolation and translation of results obtained under controlled environments to field environments is ambiguous. This review outlines the opportunities and challenges of phenotyping approaches under controlled environments complementary to conventional field trials. It gives an overview on general principles and introduces existing phenotyping facilities that take up the challenge of obtaining reliable and robust phenotypic data on climate response traits to support breeding of climate-adapted crops.

Introduction

The increase in atmospheric CO2 leads to rising temperatures and changing precipitation patterns (IPCC 2014), which have a strong impact on agricultural production. While the anticipated effects of climate change may be beneficial for the growing conditions in some regions (e.g. boreal region), climate change may cause extended or more intense periods of stress and different combinations of stress conditions in other regions (Lobell et al. 2011; Asseng et al. 2015; Leng and Hall 2019; Ray et al. 2019). The anticipated climate change affects crops in their environment in multiple ways. On the one hand, elevated atmospheric CO2 concentration stimulates photosynthesis and may benefit shoot growth and yield production as well as abiotic stress adaptation by enhanced root growth, decreased stomatal conductance, and, thus, improved water use efficiency (WUE) (Lopes and Foyer 2011). On the other hand, it is most likely that these positive effects caused by an increased CO2 concentration will be negated by increasing temperature and changes in precipitation patterns (Lobell and Gourdji 2012). Global warming shifts the timing of seasons and thus the phenology of plants: leaf development and flowering begins earlier in the year (Piao et al. 2019; Menzel et al. 2020). The extension of the frost-free period can be advantageous in certain regions, but may also lead to heat stress and summer droughts in other regions (Trnka et al. 2011; Teixeira et al. 2013), by shifting the vegetation period, which increases evaporation through plant growth in spring (Lian et al. 2020).

Abstract

Keywords

1. Introduction

2. DNA damage response

3. DDR and radiotherapy failure

4. DDR inhibitors decrease radio-resistance

5. DDR roles in chemotherapy failure

6. DDR inhibitors decrease chemo-resistance

7. Conclusions

Funding

Availability of data and material

Ethics approval and consent to participate

Consent for publication

Declaration of Competing Interest

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References

Abstract

Up to now, many improvements have been made in providing more therapeutic strategies for cancer patients. The lack of susceptibility to common therapies like chemo- and radio-therapy is one of the reasons why we need more methods in the field of cancer therapy. DNA damage response (DDR) is a set of mechanisms which identifies DNA lesions and triggers the repair process for restoring DNA after causing an arrest in the cell cycle. The ability of DDR in maintaining the genome stability and integrity can be favorable to cancerous cells which are exposed to radiation therapy or are treated with chemotherapeutic agents. When DDR mechanisms are error-free in cancer cells, they can escape the expected cellular death and display resistance to treatment. In this regard, targeting different components of DDR can help to increase the susceptibility of advanced tumors to chemo- and radio-therapy.

1. Introduction

DNA-damaging agents originating whether from endogenous or exogenous resources are known to threat the viability of every cell of our body [1]. Besides to the cellular issues arising from the great number of mutations and genome instability, the lack of proper responses can establish generations of these defective cells and put our whole body in danger [1]. DNA damage response or DDR is a precise mechanism which contains sensing the lesions, establishing signals, and finally initiating repair processes by the means of these signals [2]. During DDR, cell cycle is also affected by the mediators of DDR and is temporarily stopped in order to inhibit the replication of a defective DNA [3]. In some cases, DNA deteriorations are irreparable and thus, cell death is the only option on the table [3].

In addition to normal cells, cancerous cells are also able to use the same mechanisms for their chemotherapy- and/or radiotherapy-induced damaged DNA. Until DDR is working properly in a cancerous cell, DNA damages would not lead to cell death and thus, treatment would not be considered successful [1]. This means that despite all the advantageous impacts of DDR, it stands in the way of overcoming a great challenge in cancer therapy: resistance to our common methods, chemo- and radio-therapy. Recently, a great number of researchers have worked on targeting distinct components of DDR for enhancing the efficacy of cytotoxic treatments [4]. In this paper, we review the process of DDR briefly and explain the role of its key players in decreasing the susceptibility of cancer cells to common therapeutic procedures. Additionally, the usage of DDR inhibitors on different types of cancer would be discussed for giving an insight for the treatment of advanced stages of this lethal disease.

1- Introduction

2- In vitro studies

3- In vivo studies

4- Conclusion(s)

References

Abstract

Stem cell, one of the most exciting research areas of 21st century, is considered to have broaden the horizons of the field of biology, in general and medicine, in particular. Stem cells, owing to their unique characteristics like self-renewal, multiplication and differentiation are considered to provide an ‘all-in-one-solution’ for diverse clinical problems. Among various stem cell types, mesenchymal stem cells (MSCs) are being made the subject of the most of the studies on their therapeutic applications. It is attributable to their readily available sources, ability to immunemodulate and differentiate into mesodermal and extra-mesodermal tissues. MSCs in contrast to pluripotent stem cells carry minimal risk of teratoma formation and are free from any ethical concern. MSCs have been evaluated under innumerable studies but the definitive applications of these cells are slow, plausibly due to the incomplete understanding of their cellular physiology. Goat MSCs (gMSCs) have been isolated, culture expanded, characterized from various tissue sources and studied for their potential in vivo applications mostly in relation to human translational models. The current review throws some light on gMSC sources, characterization and potential therapeutic applications.

Introduction

The stem cells constitute an important element in the discipline of regenerative medicine that aims to address numerous incurable diseases through tissue regeneration (Gugjoo and Amarpal, 2018; Gugjoo et al. 2019). The specialized properties of selfrenewal, multiplication and differentiation of stem cells make them potential candidates for an all-in-one therapeutic solution to diverse clinical ailments. Among various stem cell types, mesenchymal stem cells (MSCs) make subject of most of the therapeutic applications (Gugjoo et al. 2019). MSCs are available in almost all the tissue types and have easy isolation and culture processes. The cells are plastic in nature, and have immunomodulatory and/ anti-inflammatory properties with minimal risk of teratogenicity and associated ethical issues unlike that of embryonic stem cells (Song et al. 2013; Gugjoo et al. 2019).

1- Introduction

2- Mesenchymal stem cells: an overview

3- Engineered MSCs

4- Engineered oncolytic viruses

5- Immune checkpoint inhibitors and oncolytic therapy

6- Non-systemic anticancer therapy with oncolytic virus-loaded MSCs

7- Systemic anticancer therapy with oncolytic virus-loaded MSCs

8- Limitations of MSC use in systemic therapy

9- MSC-mediated oncolytic virotherapy – clinical studies

10- Future directions

References

Abstract 

Progress in genetic engineering led to the emergence of some viruses as potent anticancer therapeutics. These oncolytic viruses combine self-amplification with dual antitumor action: oncolytic (destruction of cancer cells) and immunostimulatory (eliciting acquired antitumor response against cancer epitopes). As any other viruses, they trigger antiviral response upon systemic administration. Mesenchymal stem cells are immature cells capable of self-renewing and differentiating into many cell types that belong to three germinal layers. Due to their inherent tumor tropism mesenchymal stem cells loaded with oncolytic virus can improve delivery of the therapeutic cargo to cancer sites. Shielding of oncolytic viral construct from antiviral host immune response makes these cells prospective delivery vehicles to even hard-to-reach metastatic neoplastic foci. Use of mesenchymal stem cells has been criticized by some investigators as limiting proliferative abilities of primary cells and increasing the risk of malignant transformation, as well as attenuating therapeutic responses. However, majority of preclinical studies indicate safety and efficacy of mesenchymal stem cells used as carriers of oncolytic viruses. In view of contradictory postulates, the debate continues. The review discusses mesenchymal stem cells as carriers for delivery of genetically engineered oncolytic constructs and focuses on systemic approach to oncoviral treatment of some deadly neoplasms.

Introduction

Despite unquestionable progress in cancer treatment, several malignancies still tend to elude successful cure or medically-induced remission. Continued rise in morbidity in the last twenty years for gliomas, melanoma or pancreatic cancer makes them a major public health concern and a research challenge. Although radically improved outcomes might be unattainable yet, stepwise progress is likely with novel or improved treatments involving immunotherapy, cell-based therapeutics, oncolytic virotherapy and hybrid approaches. Intriguing recoveries from cancer following natural viral infection (e.g. measles) have been known to medicine since early 20th century but this early lead based on use of wild-type adenovirus, poliovirus or Coxsackie virus was marred by virus-associated morbidity and complications and was later abandoned (Kelly et al., 2007). Clinical utility of oncolytic viruses has been steadily regaining ground since the latter part of the 20th century with advances in genetic engineering. Current generation of many oncolytic viral constructs allows targeting and destroying cancer cells while toxicities to surrounding normal tissues are minimized. A concurrent development in cell-based anticancer therapies has led to the concept of oncoviral viruses’ delivery to tumors via cellular carriers. It assumes that certain types of cells pre-loaded ex vivo with some curative cargo can be administered systemically, delivered to and released in target tissues.

1- A brief history of CRISPR

2- CRISPR/Cas9: biology, functionality, and applications

3- Therapeutic targets for ex vivo cell-based CRISPR/Cas9 genome editing

4- CRISPR therapy in clinical trials

5- Challenges and opportunities

References

Abstract

The recently developed CRISPR/Cas9 technology has revolutionized the genome engineering field. Since 2016, increasing number of studies regarding CRISPR therapeutics have entered clinical trials, most of which are focusing on the ex vivo genome editing. In this review, we highlight the ex vivo cell-based CRISPR/Cas9 genome editing for therapeutic applications. In these studies, CRISPR/Cas9 tools were used to edit cells in vitro and the successfully edited cells were considered as therapeutics, which can be introduced into patients to treat diseases. Considering a large number of previous reviews have been focused on the CRISPR/Cas9 delivery methods and materials, this review provides a different perspective, by mainly introducing the targeted conditions and design strategies for ex vivo CRISPR/Cas9 therapeutics. Brief descriptions of the history, functionality, and applications of CRISPR/Cas9 systems will be introduced first, followed by the design strategies and most significant results from previous research that used ex vivo CRISPR/Cas9 genome editing for the treatment of conditions or diseases. The last part of this review includes general information about the status of CRISPR/Cas9 therapeutics in clinical trials. We also discuss some of the challenges as well as the opportunities in this research area.

A brief history of CRISPR

The term CRISPR, or the clustered regularly interspaced palindromic repeats, was first used by Jansen et al., in 2002 to describe a novel family of repetitive DNA sequences presented in the genomes of prokaryotes [1]. These unusual repeated sequences were first detected in 1987 by Nakata et al. in Escherichia coli [2], and then recognized to be widespread in archaea and bacteria by Mojica et al., in 2000 [3]. After Jansen et al. identified the CRISPR-associated (Cas) genes in 2002 [1], Mojica et al. [4], Vergnaud et al. [5], and Bolotin et al. [6] revealed the exrtachromosomal and phage-associated origins of the spacers that separate the individual direct repeats, in 2005. Speculations about CRISPR arrays as immune memory and defense mechanism against virus envisions were then proposed [6,7], while the first experimental evidence for CRISPR/Cas system based adaptive immunity was reported by Horvath et al., in 2007 [8]. Following the series discoveries on the basic function and mechanism of CRISPR systems [9–12], in 2010 Moineau et al. demonstrated the Cas9 enzyme (formerly named Cas5, COG3513, Csn1 or Csx12), which is guided by spacer sequences, cleaves target DNA [13]. In 2012, Doudna, Charpentier et al. [14], and Siksnys et al. [15] proved that Streptococcus pyogenes and Streptococcus thermophiles Cas9 can be guided by CRSIPR RNAs (crRNAs) to cleave target DNA in vitro, through forming a double-strand break (DSB). In 2013, Zhang et al. [16], Church et al. [17], and Doudna et al. [18] independently demonstrated the applications of engineered CRISPR/Cas9 systems for genome editing in mammalian cells. This represented a giant leap forward in the genome engineering field and triggered a tremendous number of studies regarding the use of the CRISPR/Cas9 platform for eukaryotic gene editing in a wide range of species, including flies [19,20], zebrafish [21–24], frogs [25], mice [26–28], rats [26,29], pigs [30], and monkeys [31,32].

1- Introduction

2- Structural elements of mRNA

3- Improving the stability and translation of mRNA

4- Avoiding immunogenicity of mRNA

5- 5 mRNA delivery

6- Preclinical and clinical advances of mRNA therapeutics

7- Concerns over the mRNA medicinal industry

8- Summary and perspective

References

Abstract

Messenger RNA (mRNA)-based therapeutics hold the potential to cause a major revolution in the pharmaceutical industry because they can be used for precise and individualized therapy, and enable patients to produce therapeutic proteins in their own bodies without struggling with the comprehensive manufacturing issues associated with recombinant proteins. Compared with the current therapeutics, the production of mRNA is much cost-effective, faster and more flexible because it can be easily produced by in vitro transcription, and the process is independent of mRNA sequence. Moreover, mRNA vaccines allow people to develop personalized medications based on sequencing results and/or personalized conditions rapidly. Along with the great potential from bench to bedside, technical obstacles facing mRNA pharmaceuticals are also obvious. The stability, immunogenicity, translation efficiency, and delivery are all pivotal issues need to be addressed. In the recently published research results, these issues are gradually being overcome by state-of-the-art development technologies. In this review, we describe the structural properties and modification technologies of mRNA, summarize the latest advances in developing mRNA delivery systems, review the preclinical and clinical applications, and put forward our views on the prospect and challenges of developing mRNA into a new class of drug.

INTRODUCTION

Messenger RNA (mRNA) has become an attractive subject of basic and applied research since it was first discovered in 1960s (Brenner et al., 1961). Accordingly, the understanding of mRNA has shifted from a simple link between DNA and protein to a versatile molecule that regulates the functions of genes in all living organisms. Based on this change, numerous types of mRNA-based therapeutics have emerged. In 1990, Wolff et al. firstly reported that intramuscular injection of mRNA into the skeletal muscle of mice led to the expression of encoding proteins (Wolff et al., 1990). Since then, mRNA- based therapeutics have been exploited in a variety of applications, including cancer immunotherapy, infectious disease vaccines, protein substitution and cellular genetic engineering. In 2001, ex vivo mRNA transfected dendritic cells entered clinical trial for the first time (Heiser et al., 2002), and hundreds of mRNA-based clinical trials have been launched over the past two decades. However, mRNA was not considered a new class of drug in the first decades after its discovery. Obstacles such as instability and immunogenicity have hampered its development, making it less pursued than DNA in gene therapy (Burnett and Rossi, 2012; Crooke et al., 2018; Geall et al., 2013; Hajj and Whitehead, 2017; Kallen and Thess, 2014; Kreiter et al., 2011; Reautschnig et al., 2017; Sahin et al., 2014; Van et al., 2015). In recent years, these key problems have been mainly solved by introducing modified nucleosides into mRNA sequences and developing various RNA packaging and delivery systems. A lot of evidences not only proved that mRNA can mediate superior transfection efficiency and longer protein expression time, but also revealed the main advantages of mRNA over DNA. The advantages of mRNA include: (1) mRNA does not need to enter the nucleus to be functional.

1- Introduction

2- Genome repair mechanisms

3- Intracellular free exogenous reporter system

4- Cell genome integrated endogenous reporter system

5- Outlooks

References

Abstract

Genome editing has become a vital tool in medical biology research. The critical mission of facilitating the progress of genome editing is to enrich different genes into positive edited cells quickly and effectively and carry out the targeted research. In recent years, researchers have established various reporter systems for selection and enrichment of editing-induced positive cells, which are based on genome repair mechanisms, such as non-homologous end joining, homology-directed repair, single strand annealing and inversion, and the principle of the expression of fluorescent protein or resistance tag after genome repair. The T7E1 assay or sequencing method can analyze the mutation of enriched cells with the results of lower background signals and higher mutation ratio. Therefore, these reporter systems can profit the characterization of genome editing effectiveness. Besides, positive cells can be cultured continuously, so this technology possesses a promising prospect in mutated cell line construction and the research of mutated cell functions. This article summarized the design principles and applications of these reporter systems and would provide a reference to construct a more perfecte evaluating system for genome editing.

Introduction

Genetic engineering started when monkey virus SV40 and E. coli bacteriophage λDNA spliced into a loop for the first time[1]. Subsequently, the discovery and research of genome repair mechanisms such as homologous recombination (HR), non-homologous end joining (NHEJ), and endonucleases provided a theoretical basis for modern genome editing technology[2,3]. In recent years, researchers have found some nucleases based on long sequence recognition, such as meganuclease[4‒7] or homing endonuclease, zinc finger nucleases (ZFNs)[8‒12], transcription activator-like effector nucleases (TALENs)[13‒17], structure-guided nucleases (SGN)[18] and clustered regularly interspaced short palindromic repeats associated protein Cas9 (CRISPR/Cas9)[19‒22]. These nucleases can accurately recognize the target sequence and induce double-strand break (DSB), and then through homologydirected repair (HDR)[23] or NHEJ[24] and other mechanisms to edit the target sequence. Genome editing technology has been applied in various fields, such as the establishment of disease models[26‒28], gene therapy[29], and gene screening[30] through different transfection techniques, such as liposomes, electroporation, viral packaging, and transmembrane peptides[25]. However, the off-target effects inherent in genome editing tools[31,32] may induce side effects such as non-target editing, erroneous phenotypes, or lethality in practical applications.

1- Introduction

2- Common lethal cancers

3- Investigating miRNA profiling in cancers

4- MiR candidates for early phase group detection

5- Conclusion

References

Abstract

Cancer is considered as a challenging lethal agent around the world and its detection at early stages would help prevention of the high mortality. Among the widely used biomarkers in clinical diagnosis of cancer, extracellular non-coding RNAs as ribonucleic acid biomarkers serve as state-of-the-art candidates for molecular diagnosis. In that regard, microRNAs are of great priority mainly because of high variety and stability in body fluids. Accordingly, common miRNAs among most prevalent cancers could help us (pre)diagnose cancer with high accuracy in target samples. In this study, common lethal cancers to humans were investigated in case of miRNA profiles to determine the possible common correlation between miRNA up-regulation or down-regulation (as a ribonucleic acid biomarker) and developing the cancers. It was shown that among the investigated miRNAs, five typical extracellular miRNAs (miR-18a, miR-21, miR-155, miR-221, and miR-375) dysregulation are predominant in most cancer varieties comprising breast, colon, lung, prostate, pancreas, gastric, ovarian, esophagus and liver. This could serve as an appropriate target site for developing point-of-care approaches for cancer detection e.g. designing diagnostic biosensor-based microarrays or kits for both quantification and qualification of the biomarkers. Besides, the miRNA candidates could be efficiently applied to cancer therapeutic approaches.

Introduction

Cancer keeps on being a remarkable cause of worldwide mortality in spite of many years of effort and cost. Deadliest types of cancers to human includes pancreas, liver, lung and bronchus, prostate/breast, colon, rectum and ovary [1–3]. Most of cancers do not induce clinical symptoms until in the later stages when the therapeutic treatment is no longer an option. However, detection of cancer at first stages, regardless of its origin, greatly increases the chance of effective treatments. In spite of much research in cancer biomarkers, only a few are considered for early diagnosis of common cancers. In addition, there is not a general biomarker for population screening in order to detect both asymptomatic cancers and early-staged cancers. Hence, investigating more sensitive and non-invasive biomarkers is still a promising challenge in cancer diagnosis and prognosis [4]. Accessing circulating cancer biomarkers through biological fluids using liquid biopsy seems to propose a promising cost-effective and non-invasive solution. Literally, cf-miRNAs are considered as ideal circulating cancer biomarkers due to their ease of access and quantification, besides integration with other macromolecules e.g. proteins, and high stability in plasma [5, 6]. MiRNAs are endogenous, small (18–24 nt), non-coding (nc) RNA molecules that play important regulatory roles in cell proliferation, apoptosis, metastasis and angiogenesis [7]. Dysregulated miRNA(s) have both oncogenic and tumor-suppressing effects depending on their corresponding targets. The increase or decrease of miRNAs is related to the role of their target genes in cancer progression or regression. MiRNAs are mainly categorized in two groups: 1) OncomiRs that are up-regulated in cancers to target protein-coding transcripts in tumor suppressive pathways, and consequently increase cell proliferation, invasion and metastasis. 2) Tumor-suppressor miRNAs that repress the oncogenic genes and their down-regulation in cancer increases the oncogenic activity [8]. MiRNAs show various expression patterns in tissue and blood of many cancers in comparison with normal samples. Furthermore, miRNA profiles in cancers with various tissue origins are distinct from each other [9].