Current Gene Therapy - Volume 20, Issue 4, 2020

Breast cancer is a serious health issue and a major concern in biomedical research. Alteration in major signaling (viz. PI3K-AKT-mTOR, Ras-Raf-MEK-Erk, NF-kB, cyclin D1, JAK-STAT, Wnt, Notch, Hedgehog signaling and apoptotic pathway) contributes to the development of major subtypes of mammary carcinoma such as HER2 positive, TNBC, luminal A and B and normal-like breast cancer. Further, mutation and expression parameters of different genes involved in the growth and development of cells play an important role in the progress of different types of carcinoma, making gene therapy an emerging new therapeutic approach for the management of life-threatening diseases like cancer. The genetic targets (oncogenes and tumor suppressor genes) play a major role in the formation of a tumor. Brk/PTK6 and mTOR are two central molecules that are involved in the regulation of numerous signaling related to cell growth, proliferation, angiogenesis, survival, invasion, metastasis, apoptosis, and autophagy. Since these two proteins are highly upregulated in mammary carcinogenesis, this can be used as targeted genes for the treatment of breast cancer. However, not much work has been done on them. This review highlights the therapeutic significance of Brk and mTOR and their associated signaling in mammary carcinogenesis, which may provide a strategy to develop gene therapy for breast cancer management.

Progress of modern dentistry is accelerating at a spectacular speed in the scientific, technological and clinical areas. Practical examples are the advancement in the digital field, which has guaranteed an average level of prosthetic practices for all patients, as well as other scientific developments, including research on stem cell biology. Given their plasticity, defined as the ability to differentiate into specific cell lineages with a capacity of almost unlimited self-renewal and release of trophic/immunomodulatory factors, stem cells have gained significant scientific and commercial interest in the last 15 years. Stem cells that can be isolated from various tissues of the oral cavity have emerged as attractive sources for bone and dental regeneration, mainly due to their ease of accessibility. This review will present the current understanding of emerging conceptual and technological issues of the use of stem cells to treat bone and dental loss defects. In particular, we will focus on the clinical application of stem cells, either directly isolated from oral sources or in vitro reprogrammed from somatic cells (induced pluripotent stem cells). Research aimed at further unraveling stem cell plasticity will allow to identify optimal stem cell sources and characteristics, to develop novel regenerative tools in dentistry.

In recent years, mesenchymal stem cells (MSCs) as a new tool for therapeutic gene delivery in clinics have attracted much attention. Their advantages cover longer lifespan, better isolation, and higher transfection efficiency and proliferation rate. MSCs are the preferred approach for cell-based therapies because of their in vitro self-renewal capacity, migrating especially to tumor tissues, as well as anti-inflammatory and immunomodulatory properties. Therefore, they have considerable efficiency in genetic engineering for future clinical applications in cancer gene therapy and other diseases. For improving therapeutic efficiency, targeted therapy of cancers can be achieved through the sustained release of therapeutic agents and functional gene expression induction to the intended tissues. The development of a new vector in gene therapy can improve the durability of a transgene expression. Also, the safety of the vector, if administered systemically, may resolve several problems, such as durability of expression and the host immune response. Currently, MSCs are prominent candidates as cell vehicles for both preclinical and clinical trials due to the secretion of therapeutic agents in several cancers. In the present study, we discuss the status of gene therapy in both viral and non-viral vectors along with their limitations. Throughout this study, the use of several nano-carriers for gene therapy is also investigated. Finally, we critically discuss the promising advantages of MSCs in targeted gene delivery, tumor inhibition and their utilization as the gene carriers in clinical situations.

Patients infected with SARS-CoV-2 carry the coronavirus disease 2019 (COVID-19) which involves multiple systems and organs with acute respiratory distress syndrome (ARDS) as the most common complication, largely due to cytokine storms or dysregulated immunity. As such, there are many severe patients with complications such as cytokine storm syndrome (CSS), who have a high fatality rate. Neither specific anti-SARS-CoV-2 drugs nor vaccines exist currently. Current treatment relies mainly on self-recovery through patients' immune function. Mesenchymal stem cells (MSCs) is a kind of multipotent tissue stem cells, which have powerful anti-inflammatory and immune regulatory functions, inhibiting the cytokine storms. In addition, MSCs have a strong ability to repair tissue damage and reduce the risk of severe complications such as acute lung injury and ARDS, and hopefully, reduce the fatality rate in these patients. There are several clinical types of research completed for treating COVID-19 with MSCs, all reporting restoration of T cells and clinical safety. Here we discuss the clinical prospect and conclude the therapeutic effects and potential mechanism for MSCs in treating COVID-19.

Background: One of the approaches to cancer gene therapy relies on tumor transfection with DNA encoding toxins under the control of tumor-specific promoters. Methods: Here, we used DNA plasmids encoding very potent anti-ERBB2 targeted toxin, driven by the human telomerase promoter or by the ubiquitous CAG promoter (pTERT-ETA and pCAG-ETA) and linear polyethylenimine to target cancer cells. Results: We showed that the selectivity of cancer cell killing by the pTERT-ETA plasmid is highly dependent upon the method of preparation of DNA-polyethylenimine complexes. After adjustment of complex preparation protocol, cell lines with high activity of telomerase promoter can be selectively killed by transfection with the pTERT-ETA plasmid. We also showed that cells transfected with pTERT-ETA and pCAG-ETA plasmids do not exert any detectable bystander effect in vitro. Conclusion: Despite this, three intratumoral injections of a plasmid-polyethylenimine complex resulted in substantial growth retardation of a poorly transfectable D2F2/E2 tumor in mice. There were no significant differences in anti-tumor properties between DNA constructs with telomerase or CAG promoters in vivo.

Background: Rheumatoid arthritis (RA) is a severe inflammatory joint disorder, and several studies have taken note of the probability that microRNAs (miRNAs) play an important role in RA pathogenesis. MiR-146 and miR-155 arose as primary immune response regulators. Mesenchymal stem cells (MSCs) immunomodulatory function is primarily regulated by paracrine factors, such as exosomes. Exosomes, which serve as carriers of genetic information in cell-to-cell communication, transmit miRNAs between cells and have been studied as vehicles for the delivery of therapeutic molecules. Aims: The current research aimed to investigate the therapeutic effect of miR-146a/miR-155 transduced mesenchymal stem cells (MSC)-derived exosomes on the immune response. Methods: Here, exosomes were extracted from normal MSCs with over-expressed miR-146a/miR-155; Splenocytes were isolated from collagen-induced arthritis (CIA) and control mice. Expression levels miR-146a and miR-155 were then monitored. Flow cytometry was performed to assess the impact of the exosomes on regulatory T-cell (Treg) levels. Expression of some key autoimmune response genes and their protein products, including retinoic acid-related orphan receptor (ROR)-γt, tumor necrosis factor (TNF)-α, interleukin (IL)-17, -6, -10, and transforming growth factor (TGF)-β in the Splenocytes was determined using both quantitative real-time PCR and ELISA. The results showed that miR-146a was mainly down-regulated in CIA mice. Treatment with MSC-derived exosomes and miR-146a/miR-155-transduced MSC-derived exosomes significantly altered the CIA mice Treg cell levels compared to in control mice. Results: Ultimately, such modulation may promote the recovery of appropriate T-cell responses in inflammatory situations such as RA. Conclusion: miR-146a-transduced MSC-derived exosomes also increased forkhead box P3 (Fox- P3), TGFβ and IL-10 gene expression in the CIA mice; miR-155 further increased the gene expressions of RORγt, IL-17, and IL-6 in these mice. Based on the findings here, Exosomes appears to promote the direct intracellular transfer of miRNAs between cells and to represent a possible therapeutic strategy for RA. The manipulation of MSC-derived exosomes with anti-inflammatory miRNA may increase Treg cell populations and anti-inflammatory cytokines.

Background: High-grade serous ovarian carcinoma (HGSOC) is one of the most common ovarian epithelial carcinomas. It is highly invasive, easily recurs after systemic treatment, and has a poor prognosis. Despite many new chemotherapeutic drugs and trials of combinations of different regimens that have been used in treatment attempts, there has been no meaningful progress in the treatment of HGSOC. With the development of gene sequencing technology, gene therapy has become a new direction for tumors treatment. It is reported that the P53 has a very high mutation rate in HGSOC, which provides a theoretical basis for the application of gene therapy in HGSOC patients. Recombinant human p53 adenovirus injection (rAd-p53) is the world's first approved oncology gene therapy drug. Case Report: In this article, we retrospectively analyzed 4 cases of HGSOC patients treated with rAdp53. Three of them were recurrent ovarian cancer, and one was the initial treatment. The treatment method was to apply recombinant human p53 adenovirus injection (rAd-p53) to the lesions for local injection, 72 hours later, the lesions were injected with bleomycin or fluorouracil, and systemic intravenous chemotherapy was performed simultaneously. After rAd-p53 treatment, one of the three relapsed ovarian cancers achieved complete remission(CR), one achieved partial remission (PR), and one was stable disease (SD); the treatment-naive patient was operated after rAd-p53 combined with neoadjuvant chemotherapy and achieved pathological CR. Under the action of various mechanisms of P53, the subsequent tumor treatment showed the characteristics of slow tumor progression, no ascites, and local recurrence. As of the end of follow-up, the OS of 4 patients was 71-120 months. Conclusion: Through the remarkable efficacy of these 4 cases, we can see that the application of rAdp53 combined with chemotherapy can effectively control tumor lesions, prolong the survival time of patients, improve the quality of life of patients, which provide valuable experiences for rAd-p53 treatment in ovarian cancer, promote the further development and progress of gene therapy in this field.