Current Gene Therapy - Volume 22, Issue 5, 2022

Background: Cancer, a malignant tumor, is caused by the failure of the mechanism that controls cell growth and proliferation. Late clinical symptoms often manifest as lumps, pain, ulcers, and bleeding. Systemic symptoms include weight loss, fatigue, and loss of appetite. It is a major disease that threatens human life and health. How to treat cancer is a long-standing problem that needs to be overcome in the history of medicine. Methods: Traditional tumor treatment methods are poorly targeted, and the side effects of treatment seriously damage the physical and mental health of patients. In recent years, with the advancement of medical science and technology, the research on gene combined with mesenchymal stem cells to treat tumors has been intensified. Mesenchymal stem cells carry genes to target cancer cells, which can achieve better therapeutic effects. Discussion: In this study, we systematically review the cancer treatment evolution from traditional methods to novel approaches that include immunotherapy, nanotherapy, stem cell theapy, and gene therapy. We provide the latest review of the application status, clinical trials, and development prospects of mesenchymal stem cells and gene therapy for cancer, as well as their integration in cancer treatment. Mesenchymal stem cells are effective carriers carrying genes and provide new clinical ideas for tumor treatment. Conclusion: This review focuses on the current status, application prospects, and challenges of mesenchymal stem cell combined gene therapy for cancer and provides new ideas for clinical research.

Like any inherited protein deficiency disease, cystic fibrosis (CF) is a good candidate for gene replacement therapy. Despite the tremendous efforts of scientists worldwide invested in developing this approach, it did not lead to the expected results for various reasons discussed in this review. At the same time, the emergence of new methods of genome editing, as well as their latest modifications, makes it possible to bypass some of the problems of “classical” CF gene therapy. The review examines potential therapeutic agents for CF gene therapy, methods and routes of delivery, as well as discusses the problem of target cells for defect correction. Based on the results of these studies, editing genetic defects in the basal cells of the lungs and their counterparts in other organs will make it possible to create a drug for treating CF with a single administration.

Background: Signal transducer and activator of transcription 3 (STAT3) is an oncogene and frequently overexpressed in cancers. However, the regulatory mechanisms of STAT3 expression are not fully understood. Poly(rC)-binding protein1 (PCBP1) is an RNA-binding protein that regulates mRNA stability, splicing, and translation. PCBP1 is a tumor suppressor and can inhibit the translation of several oncogenic genes. Objective: We aimed to understand the regulatory mechanisms of STAT3 expression. Methods: The 5' UTR or 3’ UTR regions of the human STAT3 gene were inserted upstream or downstream of the green fluorescent gene (GFP), respectively, which were used as reporter systems to analyze the inhibitory effects of PCBP1 on the STAT3 gene expression. The deletion and point mutation in 5' UTR were used to search the essential regulatory sequences of the translation inhibition. The mutations of PCBP1 protein were analyzed in the cBioPortal online service. The effects of mutated PCBP1 proteins on STAT3 expression, cancer cell proliferation, and colony formation were analyzed in oral squamous cell carcinoma (OSCC) cell lines. Results: PCBP1 inhibits mRNA translation through a motif in the 5' UTR of STAT3. Moreover, we found two leucine residues (Leu100 and Leu102) of PCBP1 protein frequently mutated in cancers. These mutations abolished the inhibition function of PCBP1 on STAT3 translation. Surprisingly, in contrast to wild-type PCBP1 protein, these mutations can promote the growth and colony formation of cancer cells. Conclusion: Overall, we demonstrate that PCBP1 can inhibit the expression of STAT3 through its 5' UTR, and two leucine residues of PCBP1 protein are essential for its functions.

Background: Cancer-related anemia (CRA) negatively influences cancer patients’ survival, disease progression, treatment efficacy, and quality of life (QOL). Current treatments such as iron therapy, red cell transfusion, and erythropoietin-stimulating agents (ESAs) may cause severe adverse effects. Therefore, the development of long-lasting and curative therapies is urgently required. Objective: In this study, a cell and gene therapy strategy was developed for in vivo delivery of EPO cDNA by way of genetic engineering of human Wharton’s jelly mesenchymal stem cells (hWJMSCs) to produce and secrete human EPO protein for extended periods after transplantation into the mice model of CRA. Methods: To evaluate CRA’s treatment in cancer-free and cancerous conditions, first, a recombinant breast cancer cell line 4T1 which expressed herpes simplex virus type 1 thymidine kinase (HSV1-TK) by a lentiviral vector encoding HSV1-TK was developed and injected into mice. After three weeks, all mice developed metastatic breast cancer associated with acute anemia. Then, ganciclovir (GCV) was administered for ten days in half of the mice to clear cancer cells. Meanwhile, another lentiviral vector encoding EPO to transduce hWJMSCs was developed. Following implantation of rhWJMSCs-EPO in the second group of mice, peripheral blood samples were collected once a week for ten weeks from both groups. Results: Analysis of peripheral blood samples showed that plasma EPO, hemoglobin (Hb), and hematocrit (Hct) concentrations significantly increased and remained at therapeutic for >10 weeks in both treatment groups. Conclusion: Data indicated that rhWJMSCs-EPO increased the circulating level of EPO, Hb, and Hct in both mouse subject groups and improved the anemia of cancer in both cancer-free and cancerous mice.

Background: Wet age-related macular degeneration (wAMD) is characterized by the presence of choroidal neovascularization (CNV). Although there are some clinical drugs targeting vascular endothelial growth factor (VEGF) and inhibiting CNV, two major side effects limit their application, including the excessive activity of anti-VEGF and frequent intraocular injections. To explore better treatment strategies, researchers developed a hypoxic modulator retinal pigment epithelium (RPE)- specific adeno-associated virus (AAV) vector expressing endostatin to inhibit CNV. However, the mechanism of endostatin is complex. Instead, soluble fms-like tyrosine kinase-1 (sFlt-1) can inhibit VEGF-induced angiogenesis through two simple and clear mechanisms, giving rise to sequestration of VEGF and forming an inactive heterodimer with the membrane-spanning isoforms of the VEGF receptor Flt-1 and kinase insert domain-containing receptor. Objective: In this study, we chose sFlt-1 as a safer substitute to treat wAMD by inhibiting VEGFinduced angiogenesis. Methods: The AAV2/8-Y733F-REG-RPE-sFlt-1 vector was delivered by intravitreal injection to the eyes of mice. AAV2/8-Y733F vector is a mutant of the AAV2/8 vector, and the REG-RPE promoter is a hypoxia-regulated RPE-specific promoter. Two animal models were used to evaluate the function of the vector. Results: In the cobalt chloride-induced hypoxia model, the results demonstrated that the AAV2/8- Y733F-REG-RPE-sFlt-1 vector induced the expression of the sFlt-1 gene in RPE cells through hypoxia. In the laser-induced CNV model, the results demonstrated that the AAV2/8-Y733F-REG-RPE-sFlt- 1 vector reduced laser-induced CNV. Conclusion: Hypoxia regulated, RPE-specific AAV vector-mediated sFlt-1 gene is a hypoxiaregulated antiangiogenic vector for wAMD.

Background: Osteoarthritis (OA) is the predominant threat to the health of the elderly, and it is crucial to understand the molecular pathogenetic mechanisms involved in it. This study aims to investigate the role of a well-studied cancer-related long non-coding RNA (lncRNA)-POU3F3 in OA and its implicated molecular mechanisms. Methods: The expression of POU3F3 and miR-29a-3p was examined in osteoarthritis patients, as well as destabilization of the medial meniscus (DMM) mouse OA model and IL- 1β induced chondrocytes cell OA model, by quantitative real-time PCR. The interaction between POU3F3, miR-29a-3p and transcription factor forkhead box O3 (FOXO3) was verified via dual-luciferase reporter analysis and RNA immunoprecipitation analyses. Cell proliferation and apoptosis were evaluated by cell viability assay and flow cytometry, respectively. Cartilage extracellular matrix (ECM) degradation was investigated with ELISA and western blotting. In addition, the in vivo regulation of POU3F3 in OA was verified by intra-articular injection of lentivirus overexpression POU3F31 in mice models. Results: The expression level of POU3F3 was decreased in OA patients/animal cartilage tissues and IL-1β-stimulated in vitro chondrocyte model. POU3F3 overexpression inhibited IL-1β-induced injury of chondrocytes, enhancing cell viability, suppressing apoptosis and inflammatory cytokine secretion, rescuing metabolic dysfunction, and restraining autophagy in vitro. Mechanistically, Luciferase reporter and RNA immunoprecipitation (RIP) assays indicated that miR-29a-3p could directly bind to POU3F3, and FOXO3 was a target gene of miR-29a-3p. Functional rescue assays confirmed this POU3F3/miR-29a-3p/FOXO3 axis in chondrocytes during OA occurrence. Furthermore, intraarticularly delivery of lentivirus containing POU3F3 alleviates the damage in mouse OA model in vivo. Conclusion: In conclusion, this work highlights the role of the POU3F3/miR-29a-3p/FOXO3 axis in the OA pathogenesis, suggesting this axis as a potential therapeutic target for OA.

Background: Lung cancer is cancer with the highest incidence in the world, and there is obvious heterogeneity within its tumor. The emergence of single-cell sequencing technology allows researchers to obtain cell-type-specific expression genes at the single-cell level, thereby obtaining information regarding the cell status and subpopulation distribution, as well as the communication behavior between cells. Many researchers have applied this technology to lung cancer research, but due to the shortcomings of insufficient sequencing depth, only a small part of the gene expression can be detected. Researchers can only roughly compare whether a few thousand genes are significant in different cell types. Methods: To fully explore the expression of all genes in different cell types, we propose a method to predict cell-type-specific genes. This method infers cell-type-specific genes based on the expression levels of genes in different tissues and cells and gene interactions. At present, biological experiments have discovered a large number of cell-type-specific genes, providing a large number of available samples for the application of deep learning methods. Results: Therefore, we fused Graph Convolutional Network (GCN) with Convolutional Neural Network( CNN) to build, model, and inferred cell-type-specific genes of lung cancer in 8 cell types. Conclusion: This method further analyzes and processes single-cell data and provides a new basis for research on heterogeneity in lung cancer tumor, microenvironment, invasion and metastasis, treatment response, drug resistance, etc.

Background: Heterogeneous nuclear ribonucleoproteins (hnRNPs), a large family of RNAbinding proteins, have been implicated in tumor progression in multiple cancer types. However, the expression pattern and prognostic value of hnRNPs in five gastrointestinal (GI) cancers, including gastric, colorectal, esophageal, liver, and pancreatic cancer, remain to be investigated. Objective: The current research aimed to identify prognostic biomarkers of the hnRNP family in five major types of gastrointestinal cancer. Methods: Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), and Kaplan-Meier Plotter were used to explore the hnRNPs expression levels concerning clinicopathological parameters and prognostic values. The protein level of hnRNPU was validated by immunohistochemistry (IHC) in human tissue specimens. Genetic alterations of hnRNPs were analyzed using cBioportal, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to illustrate the biological functions of co-expressed genes of hnRNPs. Results: The vast majority of hnRNPs were highly expressed in five types of GI cancer tissues compared to their adjacent normal tissues, and mRNA levels of hnRNPA2B1, D, Q, R, and U were significantly different in various GI cancer types at different stages. In addition, Kaplan-Meier analysis revealed that the increased hnRNPs expression levels were correlated with better prognosis in gastric and rectal cancer patients (log-rank p < 0.05). In contrast, patients with high levels of hnRNPs exhibited a worse prognosis in esophageal and liver cancer (log-rank p < 0.05). Using immunohistochemistry, we further confirmed that hnRNPU was overexpressed in gastric, rectal, and liver cancers. In addition, hnRNPs genes were altered in patients with GI cancers, and RNA-related processing was correlated with hnRNPs alterations. Conclusion: We identified differentially expressed genes of hnRNPs in tumor tissues versus adjacent normal tissues, which might contribute to predicting tumor types, early diagnosis, and targeted therapies in five major types of GI cancer.