This study aimed to investigate the expression of Twist in gastric cancer tissues and its correlation between Twist and the epithelial-mesenchymal transition (EMT). By means of RT-PCR and Western blot, the mRNA and protein expressions of Twist, E-cadherin, and Vimentin in 61 gastric cancer tissues and adjacent normal tissues were detected. The positive rates of Twist, E-cadherin, and Vimentin mRNA expression in gastric cancer tissues were 73.9. 40.6, and 60.9 %, respectively; compared to the expression of these genes in adjacent normal tissues (2.9, 75.4, and 27.5 %), the differences were significant (p < 0.05). The E-cadherin protein expression level in gastric cancer tissues was significantly lower than that in the adjacent normal tissues (p < 0.05). After the transfection of Twist siRNA into the MKN45 cells, the protein expression of Twist was significantly reduced (p < 0.05), the protein expression of E-cadherin was significantly increased, and the number of cells that passed through the Transwell chamber was significantly lower than that in the non-transfected control group as well as the transfected control group (p < 0.05). Twist may be associated with the epithelial-mesenchymal transition in gastric cancer and the tumorigenesis, invasion, and metastasis of gastric cancer.

Data have increasingly shown that melanoma differentiation associated gene-7 (Mda-7/IL-24) has growth suppression activity and can induce apoptosis in many tumor cells, but to our knowledge there have been few studies about its role in colon cancer. We examined its anti-cancer effect on colon cancer. We constructed a recombinant replication-deficient adenovirus carrying human melanoma differentiation associated gene-7 (Ad-IL-24) and examined its apoptosis-inducing efficacy on the colon cancer HT-29 cell line and on an oxaliplatin-resistant cell line HT-29/oxa, using a combination of flow cytometry, growth suppressive activity by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and xenografts. Furthermore, we tested the suppression activity of Mda-7/IL-24 on vascular endothelial growth factor (VEGF) and microvessel density (MVD), as well as the inductive effect on expression of the growth arrest and DNA damage gene (GADD) in xenograft tumors by immunohistochemistry. Melanoma differentiation associated gene-7 can inhibit the growth of colon cancer cell lines and induced apoptosis in about (5.6±0.3)% of HT-29 cells (P<0.05). Xenograft growth was retarded in vivo in mice treated with melanoma differentiation associated gene-7, but the tumor proliferation rate for this group was not significantly different in comparison to controls (P>0.05). Furthermore, melanoma differentiation associated gene-7 induced expression of a growth arrest and DNA damage (GADD) gene and reduced the expression of both VEGF and MVD in xenograft tumors. This study supports a potential therapeutic effect for melanoma differentiation associated gene-7 on colon cancer.

Lower CA125 serum levels, negative vascular invasion, and wild-type BRAF status were significantly associated with improved 2-year DFS rates among patient with stage III disease who received adjuvant chemotherapy.