[Down-regulation of survivin in growth inhibition of hepatoma cells induced by a selective cyclooxygenase-2 inhibitor]

Survivin gene expression increases gastric cancer cell lymphatic metastasis by upregulating vascular endothelial growth factor-C expression levels

The aim of this study was to investigate the correlation between the expression of survivin and vascular endothelial growth factor‑C (VEGF‑C) in gastric cancer and the pathway by which survivin may affect gastric cancer lymphatic metastasis. The study may provide novel targets for treating gastric cancer lymphatic metastasis and distal dissemination. Survivin and VEGF‑C expression in gastric carcinoma and peri‑carcinoma (2 cm away from the carcinoma) tissues, obtained from 195 patients who underwent curative gastrectomy surgery (130 cases presented with lymph node metastasis and 65 cases presented without metastasis), was examined immunohistochemically using a tissue microarray. Plasmids containing survivin and VEGF‑C shRNA were constructed and transfected into SGC‑7901 gastric cancer cells. The expression levels of the two genes were examined using western blot analysis and qPCR, and the results were statistically analyzed. The expression levels of survivin and VEGF‑C were 51.3 and 55.4%, respectively, in gastric carcinoma. Survivin and VEGF‑C were located mainly in the cytoplasm of the tumor cells. The expression levels of survivin and VEGF‑C were significantly higher in patients with lymph node metastasis than in those without metastasis (P=0.008 and 0.001, respectively). Patients with high expression levels of survivin and VEGF‑C showed significantly less favorable survival rates compared with patients with low expression levels of those two genes (P=0.003 and 0.039, respectively). Moreover, patients with co‑expression of the two genes usually had a poorer prognosis (P=0.003). However, multivariate analysis demonstrated that neither of the two genes were an independent prognostic determinant. The levels of VEGF‑C expression may be regulated by survivin expression. Conversely, inhibiting VEGF‑C gene expression by shRNA did not reduce survivin expression at the mRNA or protein levels. Survivin and VEGF‑C were expressed in gastric cancer cells and were significantly associated with lymphatic metastasis. Survivin may be a regulator of VEGF‑C expression in gastric cancer cells, and is essential in invasion and lymphatic metastasis. Moreover, survivin may be able to serve as a chemotherapy target for gastric cancer.

Nimesulide inhibited the growth of hypopharyngeal carcinoma cells via suppressing Survivin expression

BACKGROUND

The objective of this study was to evaluate the efficacy of Nimesulide, a selective cyclooxygenase-2 (COX-2) inhibitor, on the growth of hypopharyngeal carcinoma cells (FaDu) in vitro, and investigate its potential mechanism.

METHODS

After FaDu cells were treated with graded concentrations of Nimesulide for divergent time, sensitivity of cells to drug treatment was analyzed by MTT assay. Morphological changes of FaDu cells in the presence of Nimesulide were observed by acridine orange cytochemistry staining. Proliferating cells were detected using the 5-Bromo-2'-deoxy-uridine (BrdU) incorporation assay. Following cells were subjected to Nimesulide (500 μmol/l) for 6 h, 12 h and 24 h, the percentage of apoptosis was examined by flow cytometry. We detected COX-2 and Survivin expression change by RT-PCR and Western blot, and analyzed the correlation of them with the growth of FaDu cells. Additionally, we also analyzed Caspase-3, Bcl-2 and Bax expressions as markers to investigate the related pathway of Nimesulide-indued apoptosis.

RESULTS

Compared with the control group, the viabilities rates were decreased by Nimesulide in time- and dose-dependent manners, typical morphological changes of apoptotic cells were observed in the Nimesulide-treatment groups, Nimesulide could suppress the proliferation of FaDu cells significantly. The percentage of apoptosis in FaDu cells were markedly increased after Nimesulide-treatment for 6 h, 12 h and 24 h. Nimesulide down-regulated the Survivin and COX-2 expressions at mRNA and protein levels in FaDu cells. Additional analyses indicated that Bcl-2 expression was significantly decreased and the expressions of Caspase-3 as well as Bax were increased at both mRNA and protein levels.

CONCLUSIONS

Based on the induction of apoptosis and suppression of proliferation, Nimesulide could inhibit the growth of FaDu cells. Furthermore, the suppression of Survivin expression may play an important role in Nimesulide-induced growth inhibition. Nimesulide could act as an effective therapeutic agent for hypopharyngeal carcinoma therapy.

Expression of Survivin, COX-2 and VEGF in colorectal cancer and its correlation with tumor angiogenesis

AIM: To simultaneously detect the expression of Survivin, cyclooxygenasa-2 (COX-2), vascular endothelial growth factor (VEGF) and CD34 in colorectal cancer and explore its correlation with tumor angiogenesis.

METHODS: All specimens (including 26 colorectal cancer specimens, 10 colorectal polyp specimens and 7 chronic colitis specimens) were collected from September 2007 to May 2008 at the Second Affiliated Hospital of Harbin Medical University. All specimens were pathologically reevaluated to confirm the initial diagnosis. The expression of Survivin, COX-2, VEGF and CD34 in these specimens was detected by immunohistochemistry.

RESULTS: The positive rates of Survivin, COX-2 and VEGF proteins in colorectal cancer tissue were 76.9%, 80.8% and 69.28% respectively, significantly higher than those in colorectal polyp and chronic colitis tissues (P < 0.01 or 0.05). The microvascular density (MVD) revealed by CD-34 immunostaining in colorectal cancer tissue was significantly higher than that in colorectal polyp and chronic colitis tissues (23.69 ± 9.96 vs 13.10 ± 7.05 and 10.43 ± 4.24, both P < 0.01). Furthermore, the expression of Survivin, COX-2 and VEGF proteins in colorectal cancer tissue is positively correlated with tumor microvessel count (all P < 0.05). In colorectal cancer tissue, the expression of Survivin was closely correlated with that of COX-2 and VEGF (χ² = 11.18, 4.72, P < 0.05).

CONCLUSION: Survivin is probably able to promote tumor angiogenesis through regulating the expression of COX-2 and VEGF in colorectal cancer.