In vivo and in vitro inhibition of SCLC by combining dual cancer-specific recombinant adenovirus with Etoposide

Ad-VT causes ovarian cancer A2780 cell death via mitochondrial apoptosis and autophagy pathways

OBJECTIVE

The recombinant adenovirus Ad-apoptin-hTERTp-E1a (Ad-VT) to have a bi-specific oncolytic character in many tumor cells, but its action pathway in killing tumor cells has not been accurately elucidated. Here, we studied the mechanism of apoptosis and autophagy induced by Ad-VT and the interaction between autophagy and apoptosis.

METHODS

Crystal Violet staining and CCK-8 assays were used to detect the inhibitory effect of Ad-VT on ovarian cancer cells. The antitumor effect of Ad-VT in vivo was analyzed by tumor bearing nude mouse model. Subsequently, flow cytometry and fluorescence staining were used to analyze the main types of apoptosis and autophagy induced by Ad-VT.

RESULTS

In this study, through the in vitro cell inhibition assays, we found that Ad-VT has a significant inhibitory effect on ovarian cancer A2780 cells, but no significant inhibitory effect on normal ovarian epithelial cells. Then in vivo experiments showed that Ad-VT significantly inhibited tumor growth and extended the survival time of mice. Subsequent detection of the level of apoptosis found that Ad-VT can cause a strong apoptotic response and kill cells mainly through the endogenous apoptotic pathway. Through the staining analysis of LC3 and the analysis of autophagy-related proteins, it was found that Ad-VT could significantly increase the level of autophagy in A2780 cells, and this was a protective mechanism.

CONCLUSIONS

Ad-VT, which replicates under the control of the hTERT promoter and expresses apoptin protein, have significant inhibitory effect on ovarian cancer A2780 cells and promote their apoptosis and autophagy.

Oncolytic viruses in lung cancer treatment: a review article

Lung cancer has a high morbidity rate worldwide due to its resistance to therapy. So new treatment options are needed to improve the outcomes of lung cancer treatment. This study aimed to evaluate the effectiveness of oncolytic viruses (OVs) as a new type of cancer treatment. In this study, 158 articles from PubMed and Scopus from 1994 to 2022 were reviewed on the effectiveness of OVs in the treatment of lung cancer. The oncolytic properties of eight categories of OVs and their interactions with treatment options were investigated. OVs can be applied as a promising immunotherapy option, as they are reproduced selectively in different types of cancer cells, cause tumor cell lysis and trigger efficient immune responses.

Recombinant Oncolytic Adenovirus Combined with Cyclophosphamide Induces Synergy in the Treatment of Breast Cancer in vitro and in vivo

Purpose

Oncolytic virus therapy has gradually become an integral approach in cancer treatment. We explored the therapeutic effects of the combination of a dual cancer-selective anti-tumor recombinant adenovirus (Ad-Apoptin-hTERTp-E1a) and cyclophosphamide on breast cancer cells.

Methods

The inhibition of MCF-7 and MDA-MB-231 breast cancer cells by Ad-Apoptin-hTERTp-E1a (Ad-VT), cyclophosphamide, and Ad-VT + Cyclophosphamide was investigated using the CCK-8 assay. The combination index (CI) was calculated using CalcuSyn software to determine the best combination based on the inhibition rates of the different treatment combinations. The CCK-8 assay and crystal violet staining were used to detect the cytotoxicity of the combined Ad-VT and cyclophosphamide in breast cancer cells and breast epithelial cells. Subsequently, Hoechst staining, annexin V flow cytometry, and JC-1 staining were used to analyze the inhibitory pathway of Ad-VT plus cyclophosphamide on breast cancer cells. Cell migration and invasion of breast cancer cells were assessed using the cell-scratch and Transwell assays. The anti-tumor effects of different treatment groups in a tumor-bearing nude mouse model also were analyzed.

Results

The treatment combination of Ad-VT (40 MOI) and cyclophosphamide (400 µM) significantly inhibited MCF-7 and MDA-MB-231 cells and reduced the toxicity of cyclophosphamide in normal cells. Ad-VT primarily induced breast cancer cell apoptosis through the endogenous apoptotic pathway. Apoptosis was significantly increased after treatment with Ad-VT plus cyclophosphamide. The combination significantly inhibited the migration and invasion of MCF-7 and MDA-MB-231 cells. The in vivo experiments demonstrated that exposure to Ad-VT plus cyclophosphamide significantly inhibited tumor growth and extended the survival time of the nude mice.

Conclusion

Ad-VT plus cyclophosphamide reduced toxicity and exhibited increased efficacy in treating breast cancer cells.

Myricetin activates the Caspase-3/GSDME pathway via ER stress induction of pyroptosis in lung cancer cells

Pyroptosis is related to the occurrence, development, and therapeutic response of tumors, mediated by the proteins of the Gasdermin family. These proteins have become potential biomarkers for cancer treatment, and their agonists are likely to become a new direction in research and development of antitumor drugs. In this study, we found that myricetin has an inhibitory effect on lung cancer cells of the activation of pyroptosis. Analysis of the expression of Gasdermin family proteins revealed that this phenomenon was caused by the cleavage of GSDME. Subsequently, specific inhibitors, we found that caspase-3 was its upstream activation factor. In addition, mitochondrial and endoplasmic reticulum (ER) analysis showed that myricetin can cause endoplasmic reticulum stress and increase reactive oxygen species (ROS) levels. Subsequent inhibition of caspase-12 revealed that the expression levels of cleaved-caspase-3 and cleaved-GSDME were significantly reduced, resulting in the inhibition of pyroptosis. Using in vivo experiments, we also found that the treatment with myricetin can reduce tumor volume and significantly increase the level of pyroptosis-related proteins in tumor tissues. Overall, our findings show that myricetin induces cell death of lung cancer cells primarily through an ER stress pathway-induced pyroptosis. Therefore, myricetin has the potential to be used as a pyroptosis agonist in research and development of antitumor drugs.