Targeted gene therapy of the HSV-TK/hIL-12 fusion gene controlled by the hSLPI gene promoter of human non-small cell lung cancer in vitro

Efficacy of continuous i.v. infusion of recombinant human vascular endothelial growth inhibitor in combination with chemotherapy in patients with advanced lung cancer

OBJECTIVE

This study aimed to observe the efficacy of continuous i.v. infusion of Recombinant Human Vascular Endothelial Growth Inhibitor (rhVEGI) in combination with chemotherapy in patients with advanced lung cancer (ALC).

METHODS

Eighty-six patients with ALC treated at our hospital between November 2018 and May 2020 were divided into two groups of 43 patients each according to a random number table. The control group (CG) was treated with routine chemotherapy, and the experimental group (EG) was treated with continuous i.v. Infusion of rhVEGI plus chemotherapy. The two groups were compared in terms of clinical efficacy, toxic side effects, immune function (T-lymphocyte subsets CD4⁺, CD8⁺, CD4⁺/CD8⁺), changes in neovascular parameters (serum bFGF, VEGF, MMP-9), quality of life, and survival rate within 6 months between two groups.

RESULTS

The response rate (81.40%) was higher in the EG (60.47%) than in the CG (P<0.05). After treatment, CD4⁺ and CD4⁺/CD8⁺ increased in both groups, while CD8⁺, serum bFGF, VEGF, and MMP-9 levels decreased, and the improvement in the EG was better than that in the CG (P<0.05). Three months after treatment, all quality of life scores increased in both groups, and were higher in the EG than in the CG (P<0.05). The mortality rate (32.56%) was lower in the EG (32.56%) than in the CG (67.44%) (P<0.05).

CONCLUSION

Continuous i.v. infusion of rhVEGI combined with chemotherapy can effectively enhance clinical treatment efficacy, inhibit tumor cell growth, improve immune function, reduce mortality, and improve quality of life without increasing adverse effects in patients with ALC.

Strategies for Targeting Gene Therapy in Cancer Cells With Tumor-Specific Promoters

Cancer is the second cause of death worldwide, surpassed only by cardiovascular diseases, due to the lack of early diagnosis, and high relapse rate after conventional therapies. Chemotherapy inhibits the rapid growth of cancer cells, but it also affects normal cells with fast proliferation rate. Therefore, it is imperative to develop other safe and more effective treatment strategies, such as gene therapy, in order to significantly improve the survival rate and life expectancy of patients with cancer. The aim of gene therapy is to transfect a therapeutic gene into the host cells to express itself and cause a beneficial biological effect. However, the efficacy of the proposed strategies has been insufficient for delivering the full potential of gene therapy in the clinic. The type of delivery vehicle (viral or non viral) chosen depends on the desired specificity of the gene therapy. The first gene therapy trials were performed with therapeutic genes driven by viral promoters such as the CMV promoter, which induces non-specific toxicity in normal cells and tissues, in addition to cancer cells. The use of tumor-specific promoters over-expressed in the tumor, induces specific expression of therapeutic genes in a given tumor, increasing their localized activity. Several cancer- and/or tumor-specific promoters systems have been developed to target cancer cells. This review aims to provide up-to-date information concerning targeting gene therapy with cancer- and/or tumor-specific promoters including cancer suppressor genes, suicide genes, anti-tumor angiogenesis, gene silencing, and gene-editing technology, as well as the type of delivery vehicle employed. Gene therapy can be used to complement traditional therapies to provide more effective treatments.

miR‑140‑5p inhibits the proliferation of multiple myeloma cells by targeting VEGFA

MicroRNA (miR)-140-5p is associated with the growth and metastasis of various tumor cell types, yet its role in multiple myeloma (MM) remains unclear. Therefore, the present study aimed to investigate the regulatory effect of miR-140-5p on MM. Reverse transcription-quantitative PCR analysis demonstrated that miR-140-5p was downregulated in MM cell lines, particularly in U266 and RPMI 8226 cells. A Cell Counting Kit-8, wound healing and Transwell assays, as well as flow cytometry indicated that a miR-140-5p mimic could suppress cell viability, migration and invasion. In addition, the mimic promoted apoptosis of U266 and RPMI 8226 cells. Western blot data demonstrated that transfection with miR-140-5p mimic significantly reduced the expression levels of Ki-67, cyclin D1, vimentin, Snail, matrix metalloproteinase (MMP)-2 and MMP-3. Moreover, as predicted by TargetScan7.2 and verified by luciferase activity assay, it was demonstrated that vascular endothelial growth factor A (VEGFA) was targeted by miR-140-5p. Further experiments indicated that VEGFA overexpression promoted cell viability, migration and invasion and suppressed apoptosis of MM cells, and that the miR-140-5p mimic partially reversed the effects of VEGFA overexpression. Therefore, miR-140-5p suppressed MM progression by targeting VEGFA. The present findings provide insight into potential therapeutic strategies for the treatment of MM.

Effective inhibition of cancer cells by recombinant adenovirus expressing EGFR-targeting artificial microRNA and reversed-caspase-3

The EGFR-targeting cancer therapies are commonly facing drug resistance, mostly due to mutations. Gene therapy with artificial microRNA targeting EGFR conserved sequence may avoid such problem. In this study, we constructed a recombinant adenovirus expressing EGFR-targeting artificial microRNA and active revCASP3 (Ad-EC), under the control of tumor-specific SLPI promoter, and evaluated its inhibitory effect on HEP-2 cancer cells both in vitro and in vivo. MTT assay showed that cell growth inhibition rate at 72h was 44.0% in Ad-EC group at MOI 50, while the rate was 7.7% in the control virus Ad-GFP group and 3.6% in Cetuximab (500 μg/ml) group respectively. Flow cytometry analysis revealed the late apoptotic cells rate was 36.1% in Ad-EC group, significantly higher than 6.5% of Ad-GFP group (p < 0.001). When Ad-EC (MOI 50) was combined with CDDP (0.25 μg/ml), late apoptotic cells rate increased to 61.2%, significantly higher than each monotherapy group (P < 0.001). The real-time xCELLigence system recorded an effective cell growth inhibition in Ad-EC and CDDP groups, and more enhanced effect in Ad-EC plus CDDP group. Western blot revealed that Ad-EC could inhibit the activation of AKT pathway and ERK1/2 pathway, while Cetuximab had the AKT pathway over-activated. In vivo experiments with HEP-2 xenograft in nude mice confirmed the tumor inhibition in Ad-EC, CDDP and Ad-EC plus CDDP groups compared with PBS group (P < 0.01). Collectively, these data support the effective inhibition of cancer cells by this novel gene therapy strategy.