Expression and significance of TWIST basic helix-loop-helix protein over-expression in gastric cancer.

TWIST protein has been implicated in neoplastic transformation and development of some cancers. In this study, we aimed to investigate the expression of TWIST in gastric cancer and its clinical significance. A total of 76 cases of archival gastric cancer tissues were immunohistochemically evaluated for TWIST expression, and its expression was correlated with clinicopathological parameters. Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the mRNA of TWIST in four gastric cancer cell lines and a normal immortalised gastric epithelial cell line (GES-1). The expression of TWIST protein in these cell lines and 14 pairs of fresh gastric carcinoma and adjacent normal tissue samples was detected by Western blotting. TWIST expression increased in diffuse-type gastric carcinoma compared with intestinal-type gastric carcinoma (26/42, 61.9% versus 9/34, 26.5%, p<0.05). TWIST expression was significantly increased in 35 (46.1%) of the 76 cancers and correlated with lymph node metastasis (node positive rate 60.4%; node negative rate 21.4%; p<0.05). The expression of TWIST protein was higher in 9/14 (64.3%) fresh cancer tissues compared with adjacent normal tissues. The expression of mRNA and protein of TWIST in gastric cancer cell lines was up-regulated compared with that in GES-1. TWIST was highly expressed in gastric cancer. Its up-regulation was associated with the neoplastic transformation and subsequent development of gastric cancer. Therefore, TWIST may be a useful prognostic marker and target for gastric cancer therapy.