Prognostic utility of gene therapy with herpes simplex virus thymidine kinase for patients with high-grade malignant gliomas: a systematic review and meta analysis

Application Perspectives of Nanomedicine in Cancer Treatment

Cancer is a disease that seriously threatens human health. Based on the improvement of traditional treatment methods and the development of new treatment modes, the pattern of cancer treatment is constantly being optimized. Nanomedicine plays an important role in these evolving tumor treatment modalities. In this article, we outline the applications of nanomedicine in three important tumor-related fields: chemotherapy, gene therapy, and immunotherapy. According to the current common problems, such as poor targeting of first-line chemotherapy drugs, easy destruction of nucleic acid drugs, and common immune-related adverse events in immunotherapy, we discuss how nanomedicine can be combined with these treatment modalities, provide typical examples, and summarize the advantages brought by the application of nanomedicine.

Targeting stanniocalcin-1-expressing tumor cells elicits efficient antitumor effects in a mouse model of human lung cancer

Lung cancer is the most common cause of cancer‐related death in developed countries; therefore, the generation of effective targeted therapeutic regimens is essential. Recently, gene therapy approaches toward malignant cells have emerged as attractive molecular therapeutics. Previous studies have indicated that stanniocalcin‐1 (STC‐1), a hormone involved in calcium and phosphate homeostasis, positively regulates proliferation, apoptosis resistance, and glucose metabolism in lung cancer cell lines. In this study, we investigated if targeting STC‐1 in tumor cells could be a promising strategy for lung cancer gene therapy. We confirmed that STC‐1 levels in peripheral blood were higher in lung cancer patients than in healthy donors and that STC‐1 expression was observed in five out of eight lung cancer cell lines. A vector expressing a suicide gene, uracil phosphoribosyltransferase (UPRT), under the control of the STC‐1 promoter, was constructed (pP_STC‐1‐UPRT) and transfected into three STC‐1‐positive cell lines, PC‐9, A549, and H1299. When stably transfected, we observed significant cell growth inhibition using 5‐fluorouracil (5‐FU) treatment. Furthermore, growth of the STC‐1‐negative lung cancer cell line, LK‐2 was significantly arrested when combined with STC‐1‐positive cells transfected with pP_STC‐1‐UPRT.

We believe that conferring cytotoxicity in STC‐1‐positive lung cancer cells using a suicide gene may be a useful therapeutic strategy for lung cancer.

The rapidly evolving state of gene therapy

Gene therapy is emerging as a viable option for clinical therapy of monogenic disorders and other genetically defined diseases, with approved gene therapies available in Europe and newly approved gene therapies in the United States. In the past 10 years, gene therapy has moved from a distant possibility, even in the minds of much of the scientific community, to being widely realized as a valuable therapeutic tool with wide-ranging potential. The U.S. Food and Drug Administration has recently approved Luxturna (Spark Therapeutics Inc, Philadelphia, PA, USA), a recombinant adeno-associated virus (rAAV) 2 gene therapy for one type of Leber congenital amaurosis 2 ( 1 , 2 ). The European Medicines Agency (EMA) has approved 3 recombinant viral vector products: Glybera (UniQure, Amsterdam, The Netherlands), an rAAV vector for lipoprotein lipase deficiency; Strimvelis (Glaxo Smith-Kline, Brentford, United Kingdom), an ex vivo gammaretrovirus-based therapy for patients with adenosine deaminase-deficient severe combined immune deficiency (ADA-SCID); and Kymriah (Novartis, Basel, Switzerland), an ex vivo lentivirus-based therapy to engineer autologous chimeric antigen-receptor T (CAR-T) cells targeting CD19-positive cells in acute lymphoblastic leukemia. These examples will be followed by the clinical approval of other gene therapy products as this field matures. In this review we provide an overview of the state of gene therapy by discussing where the field stands with respect to the different gene therapy vector platforms and the types of therapies that are available.-Gruntman, A. M., Flotte, T. R. The rapidly evolving state of gene therapy.

Changing paradigms for targeted therapies against diffuse infiltrative gliomas: tackling a moving target

Introduction: Gliomas are highly heterogeneous primary brain tumors which result in a disproportionately high degree of morbidity and mortality despite their locoregional occurrence. Advances in the understanding of the biological makeup of these malignancies have yielded a number of potential tumor-driving pathways which have been identified as rational targets for therapy. However, early trials of agents that target these pathways have uniformly failed to yield improvement in outcomes in patients with malignant gliomas. Areas covered: This review provides an overview of the most common biological features of gliomas and the strategies to target the same; in addition, the current status of immunotherapy and biological therapies are outlined and the future directions to tackle the challenges of therapy for gliomas are examined. Expert opinion: The limitations of current treatments are attributed to the inability of most of these agents to cross the blood-brain barrier and to the intrinsic heterogeneity of the tumors that result in treatment resistance. The recent emergence of immune-mediated and biological therapies and of agents that target metabolic pathways in gliomas have provided strategies that may overcome tumor heterogeneity and ongoing trials of such agents are anticipated to yield improved outcomes.

Development of a genetic sensor that eliminates p53 deficient cells

The TP53 gene fulfills a central role in protecting cells from genetic insult. Given this crucial role it might be surprising that p53 itself is not essential for cell survival. Indeed, TP53 is the single most mutated gene across different cancer types. Thus, both a theoretical and a question of significant practical applicability arise: can cells be programmed to make TP53 an essential gene? Here we present a genetic p53 sensor, in which the loss of p53 is coupled to the rise of HSV-TK expression. We show that the sensor can distinguish both p53 knockout and cells expressing a common TP53 cancer mutation from otherwise isogenic TP53 wild-type cells. Importantly, the system is sensitive enough to specifically target TP53 loss-of-function cells with the HSV-TK pro-drug Ganciclovir both in vitro and in vivo. Our work opens new ways to programming cell intrinsic transformation protection systems that rely on endogenous components.

TP53 is mutated in many cancers, a system to detect and selectively eliminate p53 mutant cells is an attractive therapeutic strategy. Here, the authors present a genetic sensor that can detect p53 activity and is coupled to the thymidine kinase gene, which can activate the drug Ganciclovir, resulting in cell death.

Immunotherapy and gene therapy as novel treatments for cancer

The immune system interacts closely with tumors during the disease development and progression to metastasis. The complex communication between the immune system and the tumor cells can prevent or promote tumor growth. New therapeutic approaches harnessing protective immunological mechanisms have recently shown very promising results. This is performed by blocking inhibitory signals or by activating immunological effector cells directly. Immune checkpoint blockade with monoclonal antibodies directed against the inhibitory immune receptors CTLA-4 and PD-1 has emerged as a successful treatment approach for patients with advanced melanoma. Ipilimumab is an anti-CTLA-4 antibody which demonstrated good results when administered to patients with melanoma. Gene therapy has also shown promising results in clinical trials. Particularly, Herpes simplex virus (HSV)-mediated delivery of the HSV thymidine kinase (TK) gene to tumor cells in combination with ganciclovir (GCV) may provide an effective suicide gene therapy for destruction of glioblastomas, prostate tumors and other neoplasias by recruiting tumor-infiltrating lymphocytes into the tumor. The development of new treatment strategies or combination of available innovative therapies to improve cell cytotoxic T lymphocytes trafficking into the tumor mass and the production of inhibitory molecules blocking tumor tissue immune-tolerance are crucial to improve the efficacy of cancer therapy.

An overview of the infection of CMV, HSV 1/2 and EBV in Mexican patients with glioblastoma multiforme

Several risk factors are involved in glioblastoma, including cytomegalovirus (CMV). This research was carried out to determine the rate of CMV infection, as well as HSV 1/2 and EBV in brain tissue, in patients with glioblastomamultiforme (GBM). The tissues were tested using immunohistochemistry, PCR, in situ hybridization and real-time PCR. At least, one HHV was detected in 21/29 (72%) patients as follows: single infections with HSV-1/2 in 4/21 (19%), EBV in 6/21 (28.6%) and CMV in 1/21 (4.8%). Mixed viral infection, HSV-1/2 and EBV were detected in 4/21 patients (19%), CMV and EBV in 5/21 (23.8%), and HSV-1/2, EBV, and CMV in 1/21. The CMV viral load ranged from 3×10² to 4.33×10⁵ genome/100ng of tissue. Genotype based on CMV gB was 3/7 where 2/3 was gB1 and 1/3 gB4. HSV, EBV and CMV were frequently found in brain tissues, more in mix in a population reported as highly seropositive.

Specific Colon Cancer Cell Cytotoxicity Induced by Bacteriophage E Gene Expression under Transcriptional Control of Carcinoembryonic Antigen Promoter

Colorectal cancer is one of the most prevalent cancers in the world. Patients in advanced stages often develop metastases that require chemotherapy and usually show a poor response, have a low survival rate and develop considerable toxicity with adverse symptoms. Gene therapy may act as an adjuvant therapy in attempts to destroy the tumor without affecting normal host tissue. The bacteriophage E gene has demonstrated significant antitumor activity in several cancers, but without any tumor-specific activity. The use of tumor-specific promoters may help to direct the expression of therapeutic genes so they act against specific cancer cells. We used the carcinoembryonic antigen promoter (CEA) to direct E gene expression (pCEA-E) towards colon cancer cells. pCEA-E induced a high cell growth inhibition of human HTC-116 colon adenocarcinoma and mouse MC-38 colon cancer cells in comparison to normal human CCD18co colon cells, which have practically undetectable levels of CEA. In addition, in vivo analyses of mice bearing tumors induced using MC-38 cells showed a significant decrease in tumor volume after pCEA-E treatment and a low level of Ki-67 in relation to untreated tumors. These results suggest that the CEA promoter is an excellent candidate for directing E gene expression specifically toward colon cancer cells.