GOLPH2-regulated oncolytic adenovirus, GD55, exerts strong killing effect on human prostate cancer stem-like cells in vitro and in vivo.

GOLPH2 (also called GP73) is a Golgi glycoprotein, which has been identified as a novel tumor marker upregulated in various cancers, including prostate cancer (PCa). GD55 is a novel GOLPH2-regulated oncolytic adenovirus that exhibits a strong killing effect on hepatoma cells. Here, we investigate the antitumor effect of GD55 on prostate cancer stem cell (CSC)-like cells in vitro and in vivo. Prostate CSC-like sphere cells were acquired and enriched by culturing DU145, LNCap or P3 prostate cancer cells in suspension. The prostate CSC-like sphere cells were capable of self-renewal, differentiation and quiescence, displaying tumorigenic feature and chemo-resistance to 5-FU, doxorubicin and DDP. Treatment with GD55 (1, 5, 10 MOI) dose-dependently suppressed the viability of DU145 sphere cells, which was a more pronounced compared to its cytotoxic action on the parental DU145 cells. In a mouse xenograft prostate CSC-like model, intratumoral injection of GD55 markedly suppressed the growth rate of xenograft tumors and induced higher levels of cell death and necrosis within the tumor tissues. Our results demonstrate that GD55 infection exerts strong anticancer effects on prostate CSC-like cells in vitro and in vivo, and has a potential to be used in the clinical therapy of PCa.

Oncolytic viruses against cancer stem cells: A promising approach for gastrointestinal cancer.

Gastrointestinal cancer has been one of the five most commonly diagnosed and leading causes of cancer mortality over the past few decades. Great progress in traditional therapies has been made, which prolonged survival in patients with early cancer, yet tumor relapse and drug resistance still occurred, which is explained by the cancer stem cell (CSC) theory. Oncolytic virotherapy has attracted increasing interest in cancer because of its ability to infect and lyse CSCs. This paper reviews the basic knowledge, CSC markers and therapeutics of gastrointestinal cancer (liver, gastric, colon and pancreatic cancer), as well as research advances and possible molecular mechanisms of various oncolytic viruses against gastrointestinal CSCs. This paper also summarizes the existing obstacles to oncolytic virotherapy and proposes several alternative suggestions to overcome the therapeutic limitations.

Anti-tumor effects of Astragalus on hepatocellular carcinoma in vivo.

OBJECTIVE: The objective of the present study is to investigate the anti-proliferation activity of Astragalus on human hepatocellular carcinoma (HCC) cells and its mechanism. MATERIALS AND METHODS: Hepatic cancer H22 bearing mice were used to study the anti-hepatocarcinoma activity of Astragalus in vivo. The growth curve and inhibitory rate of tumor growth were measured. Cell apoptosis of each group was measured by flow cytometry (FCM). Protein expression of Bax and Bcl-2 were analyzed by immunohistochemistry (IHC). The Statistical Package for Social Sciences version 13.0 (SPSS Inc, Chicago, IL) was used for standard statistical analysis including one-way ANOVA and Student's t-test. A value of P<0.05 was considered to be statistically significant. RESULTS: Astragalus significantly inhibited the growth of H22 carcinoma, with an inhibitory rate of 17.28-52.36%. FCM and immunohistochemical assay show that the cell apoptosis rate and protein expression of Bax and Bax/Bcl-2 ratio of H22 transplanted tumor in Astragalus treated group were significantly higher than the control group (P<0.05). The protein expression of Bcl-2 was significantly lower than control (P<0.05). CONCLUSION: The results of the present study suggest that Astragalus has significant anti-tumor effect in vivo in inducing apoptosis of H22 tumor cells by promoting protein expression of Bax, decreasing protein expression of Bcl-2 gene, and markedly increasing the Bax/Bcl-2 ratio.