The innovative evolution of cancer gene and cellular therapies

Current advances in cell therapeutics: A biomacromolecules application perspective

INTRODUCTION

Many chronic diseases have evolved and to circumvent the limitations of using conventional drug therapies, smart cell encapsulating delivery systems have been explored to customize the treatment with alignment to disease longevity. Cell therapeutics has advanced in tandem with improvements in biomaterials that can suitably deliver therapeutic cells to achieve targeted therapy. Among the promising biomacromolecules for cell delivery are those that share bio-relevant architecture with the extracellular matrix and display extraordinary compatibility in the presence of therapeutic cells. Interestingly, many biomacromolecules that fulfil these tenets occur naturally and can form hydrogels.

AREAS COVERED

This review provides a concise incursion into the paradigm shift to cell therapeutics using biomacromolecules. Advances in the design and use of biomacromolecules to assemble smart therapeutic cell carriers is discussed in light of their pivotal role in enhancing cell encapsulation and delivery. In addition, the principles that govern the application of cell therapeutics in diabetes, neuronal disorders, cancers and cardiovascular disease are outlined.

EXPERT OPINION

Cell therapeutics promises to revolutionize the treatment of various secretory cell dysfunctions. Current and future advances in designing functional biomacromolecules will be critical to ensure that optimal delivery of therapeutic cells is achieved with desired biosafety and potency.

Step-by-Step Immune Activation for Suicide Gene Therapy Reinforcement

Gene-directed enzyme prodrug gene therapy (GDEPT) theoretically represents a useful method to carry out chemotherapy for cancer with minimal side effects through the formation of a chemotherapeutic agent inside cancer cells. However, despite great efforts, promising preliminary results, and a long period of time (over 25 years) since the first mention of this method, GDEPT has not yet reached the clinic. There is a growing consensus that optimal cancer therapies should generate robust tumor-specific immune responses. The advent of checkpoint immunotherapy has yielded new highly promising avenues of study in cancer therapy. For such therapy, it seems reasonable to use combinations of different immunomodulators alongside traditional methods, such as chemotherapy and radiotherapy, as well as GDEPT. In this review, we focused on non-viral gene immunotherapy systems combining the intratumoral production of toxins diffused by GDEPT and immunomodulatory molecules. Special attention was paid to the applications and mechanisms of action of the granulocyte-macrophage colony-stimulating factor (GM–CSF), a cytokine that is widely used but shows contradictory effects. Another method to enhance the formation of stable immune responses in a tumor, the use of danger signals, is also discussed. The process of dying from GDEPT cancer cells initiates danger signaling by releasing damage-associated molecular patterns (DAMPs) that exert immature dendritic cells by increasing antigen uptake, maturation, and antigen presentation to cytotoxic T-lymphocytes. We hypothesized that the combined action of this danger signal and GM–CSF issued from the same dying cancer cell within a limited space would focus on a limited pool of immature dendritic cells, thus acting synergistically and enhancing their maturation and cytotoxic T-lymphocyte attraction potential. We also discuss the problem of enhancing the cancer specificity of the combined GDEPT–GM–CSF–danger signal system by means of artificial cancer specific promoters or a modified delivery system.

Precision Oncology, Signaling and Anticancer Agents in Cancer Therapeutics

BACKGROUND

The global alliance for genomics and healthcare facilities provides innovational solutions to expedite research and clinical practices for complex and incurable health conditions. Precision oncology is an emerging field explicitly tailored to facilitate cancer diagnosis, prevention and treatment based on patients' genetic profile. Advancements in "omics" techniques, next-generation sequencing, artificial intelligence and clinical trial designs provide a platform for assessing the efficacy and safety of combination therapies and diagnostic procedures.

METHOD

Data were collected from Pubmed and Google scholar using keywords: "Precision medicine", "precision medicine and cancer", "anticancer agents in precision medicine" and reviewed comprehensively.

RESULTS

Personalized therapeutics including immunotherapy, cancer vaccines, serve as a groundbreaking solution for cancer treatment. Herein, we take a measurable view of precision therapies and novel diagnostic approaches targeting cancer treatment. The contemporary applications of precision medicine have also been described along with various hurdles identified in the successful establishment of precision therapeutics.

CONCLUSION

This review highlights the key breakthroughs related to immunotherapies, targeted anticancer agents, and target interventions related to cancer signaling mechanisms. The success story of this field in context to drug resistance, safety, patient survival and in improving quality of life is yet to be elucidated. We conclude that, in the near future, the field of individualized treatments may truly revolutionize the nature of cancer patient care.

Implementation of Nanoparticles in Cancer Therapy

Cancer is a wide group of diseases and generally characterized by uncontrolled proliferation of cells whose metabolic activities are disrupted. Conventionally, chemotherapy, radiotherapy, and surgery are used in the treatment of cancer. However, in theory, even a single cancer cell may trigger recurrence. Therefore, these treatments cannot provide high survival rate for deadly types. Identification of alternative methods in treatment of cancers is inevitable because of adverse effects of conventional methods. In the last few decades, nanotechnology developed by scientists working in different disciplines—physics, chemistry, and biology—offers great opportunities. It is providing elimination of both circulating tumor cells and solid cancer cells by targeting cancer cells. In this chapter, inadequate parts of conventional treatment methods, nanoparticle types used in new treatment methods of cancer, and targeting methods of nanoparticles are summarized; furthermore, recommendations of future are provided.

Role of Recombinant DNA Technology to Improve Life

In the past century, the recombinant DNA technology was just an imagination that desirable characteristics can be improved in the living bodies by controlling the expressions of target genes. However, in recent era, this field has demonstrated unique impacts in bringing advancement in human life. By virtue of this technology, crucial proteins required for health problems and dietary purposes can be produced safely, affordably, and sufficiently. This technology has multidisciplinary applications and potential to deal with important aspects of life, for instance, improving health, enhancing food resources, and resistance to divergent adverse environmental effects. Particularly in agriculture, the genetically modified plants have augmented resistance to harmful agents, enhanced product yield, and shown increased adaptability for better survival. Moreover, recombinant pharmaceuticals are now being used confidently and rapidly attaining commercial approvals. Techniques of recombinant DNA technology, gene therapy, and genetic modifications are also widely used for the purpose of bioremediation and treating serious diseases. Due to tremendous advancement and broad range of application in the field of recombinant DNA technology, this review article mainly focuses on its importance and the possible applications in daily life.

Synergistic effects of overexpression of BMP‑2 and TGF‑β3 on osteogenic differentiation of bone marrow mesenchymal stem cells

Bone morphogenetic protein 2 (BMP-2) and transforming growth factor β (TGF-β) isoforms are important in advancing bone regeneration. The aim of the present study was to investigate the positive and reciprocal effect of TGF-β3, one of the three TGF-β isoforms, on BMP-2 in promoting osteogenic differentiation. Exogenous BMP-2 and TGF-β3 genes were separately, and in combination, overexpressed in rabbit bone marrow-derived mesenchymal stem cells (rBMSCs). Expression levels of BMP-2 and TGF-β3 were evaluated using reverse-transcription-polymerase chain reaction (RT-PCR) and Western blotting assays. Furthermore, the osteogenic differentiation capacities of BMSCs were assessed by measuring Alizarin Red S staining, an alkaline phosphatase activity assay, and quantification of the osteogenic-specific genes, Runt-related transcription factor 2 (Runx2) and Osterix (Osx). Using lentiviral-mediated transfection, robust co-transfection efficiency of >90% was achieved. RT-PCR and immunoblotting results indicated a marked elevated expression of BMP-2 and TGF-β3 in rBMSCs undergoing co-transfection, compared with transfection with BMP-2 or TGF-β3 alone, indicating that BMP-2 and TGF-β3 are synergistically expressed in rBMSCs. Furthermore, enhanced osteogenic differentiation was observed in rBMSCs co-transfected with BMP-2/TGF-β3. The present study successfully delivered BMP-2 together with TGF-β3 into rBMSCs with high efficiency for the first time. Furthermore, TGF-β3 overexpression was demonstrated to enhance the osteogenic efficacy of BMP-2 in rBMSCs, and vice versa. This provides a potential clinical therapeutic approach for regenerating the function of osseous tissue, and may present a promising strategy for bone defect healing.

Mussel-inspired alginate gel promoting the osteogenic differentiation of mesenchymal stem cells and anti-infection

Alginate hydrogels have been used in cell encapsulation for many years but a prevalent issue with pure alginates is that they are unable to provide enough bioactive properties to interact with mammalian cells. This paper discusses the modification of alginate with mussel-inspired dopamine for cell loading and anti-infection. Mouse bone marrow stem cells were immobilized into alginate and alginate-dopamine beads and fibers. Through live-dead and MTT assay, alginates modified by dopamine promoted cell viability and proliferation. In vitro cell differentiation results showed that such an alginate-dopamine gel can promote the osteogenic differentiation of mesenchymal stem cell after PCR and ALP assays. In addition to that, the adhesive prosperities of dopamine allowed for coating the surface of alginate-dopamine gel with silver nanoparticles, which provided the gel with significant antibacterial characteristics. Overall, these results demonstrate that a dopamine-modified alginate gel can be a great tool for cell encapsulation to promote cell proliferation and can be applied to bone regeneration, especially in contaminated bone defects.

Therapeutic properties of a vector carrying the HSV thymidine kinase and GM-CSF genes and delivered as a complex with a cationic copolymer

BACKGROUND

Gene-directed enzyme prodrug therapy (GDEPT) represents a technology to improve drug selectivity for cancer cells. It consists of delivery into tumor cells of a suicide gene responsible for in situ conversion of a prodrug into cytotoxic metabolites. Major limitations of GDEPT that hinder its clinical application include inefficient delivery into cancer cells and poor prodrug activation by suicide enzymes. We tried to overcome these constraints through a combination of suicide gene therapy with immunomodulating therapy. Viral vectors dominate in present-day GDEPT clinical trials due to efficient transfection and production of therapeutic genes. However, safety concerns associated with severe immune and inflammatory responses as well as high cost of the production of therapeutic viruses can limit therapeutic use of virus-based therapeutics. We tried to overcome this problem by using a simple nonviral delivery system.

METHODS

We studied the antitumor efficacy of a PEI (polyethylenimine)-PEG (polyethylene glycol) copolymer carrying the HSVtk gene combined in one vector with granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA. The system HSVtk-GM-CSF/PEI-PEG was tested in vitro in various mouse and human cell lines, ex vivo and in vivo using mouse models.

RESULTS

We showed that the HSVtk-GM-CSF/PEI-PEG system effectively inhibited the growth of transplanted human and mouse tumors, suppressed metastasis and increased animal lifespan.

CONCLUSIONS

We demonstrated that appreciable tumor shrinkage and metastasis inhibition could be achieved with a simple and low toxic chemical carrier - a PEI-PEG copolymer. Our data indicate that combined suicide and cytokine gene therapy may provide a powerful approach for the treatment of solid tumors and their metastases.

Glycol chitosan nanoparticles as specialized cancer therapeutic vehicles: sequential delivery of doxorubicin and Bcl-2 siRNA

Conventional chemotherapy is plagued with adverse side effects because cancer treatments are subject to numerous variations, most predominantly from drug resistance. Accordingly, multiple or multistage chemotherapeutic regimens are often performed, combining two or more drugs with orthogonal and possibly synergistic mechanisms. In this respect, glycol chitosan (GC)-based nanoparticles (CNPs) serve as an effective platform vehicle that can encapsulate both chemotherapeutics and siRNA to achieve maximal efficacy by overcoming resistance. Herein, DOX-encapsulated CNPs (DOX-CNPs) or Bcl-2 siRNA-encapsulated CNPs (siRNA-CNPs) exhibited similar physicochemical properties, including size, surface properties and pH sensitive behavior, regardless of the different physical features of DOX and Bcl-2 siRNA. We confirmed that the CNP platform applied to two different types of drugs results in similar in vivo biodistribution and pharmacokinetics, enhancing treatment in a dose-dependent fashion.

Tissue-specific attenuation of oncolytic sindbis virus without compromised genetic stability

Wild-type Sindbis virus (SV) shows promise as an oncolytic agent, although potential off-target replication is a safety concern. To remove possible pathology reflecting virus replication in liver, muscle, and/or hematopoietic cells, microRNA (miR)-response elements (MREs) to liver-specific miR122, muscle-specific miR133a and miR206, or hematopoietic-specific miR142-3p were inserted into the Sindbis viral genome. We compared the effectiveness of MREs in two distinct genomic locations and found better tissue-specific attenuation when they were inserted into the structural polyprotein coding region (up to 6000-fold selectivity with miR142-3p) rather than into the 3' untranslated region (up to 850-fold with miR142-3p). While this degree of tissue-specific attenuation may be effective for relieving pathology in vivo, genetic instability of RNA viruses raises concerns over the mutation or loss of MREs conferring safety. Genetically modified SVs containing a reporter transgene, used as a surrogate for virus replication, mutated quickly in vitro, losing 50% transgene sequence within 6.2 passages. Using a shorter insert containing MREs but no transgene, complete genetic stability was observed over at least 10 passages. We conclude that SV may be genetically modified to improve clinical properties, but attention must be paid to ensure that genetic stability is sufficient for intended applications.

Gene therapy as a new treatment option for inherited monogenic diseases

BACKGROUND

Gene therapy, replacing a defective gene by a functional copy, has been in development for more than 40years. Initial efforts involved engineering viral vectors to deliver genes to the appropriate cells. Early successes in severe combined immunodeficiency (SCID) were later derailed by safety issues including host reaction to the vector and gene insertion near promoters that favored secondary leukemia.

METHODS

Systematic review of the literature using PubMed.gov with key word gene therapy from 1972 to March 2013. Google search with key word gene therapy.

RESULTS

Despite early setbacks, progresses for monogenic diseases continued unabated. Patients with SCIDs have been cured and the first gene therapy has been approved for lipoprotein lipase deficiency. Many clinical research studies are ongoing as part of systematic clinical development program with a view to have more gene therapies approved.

CONCLUSION

Our review highlights progresses and questions that remain to be answered to make gene therapy an integral part of our therapeutic arsenal.

Gene therapy on the move

The first gene therapy clinical trials were initiated more than two decades ago. In the early days, gene therapy shared the fate of many experimental medicine approaches and was impeded by the occurrence of severe side effects in a few treated patients. The understanding of the molecular and cellular mechanisms leading to treatment- and/or vector-associated setbacks has resulted in the development of highly sophisticated gene transfer tools with improved safety and therapeutic efficacy. Employing these advanced tools, a series of Phase I/II trials were started in the past few years with excellent clinical results and no side effects reported so far. Moreover, highly efficient gene targeting strategies and site-directed gene editing technologies have been developed and applied clinically. With more than 1900 clinical trials to date, gene therapy has moved from a vision to clinical reality. This review focuses on the application of gene therapy for the correction of inherited diseases, the limitations and drawbacks encountered in some of the early clinical trials and the revival of gene therapy as a powerful treatment option for the correction of monogenic disorders.