Clinical significance of loss of Fhl1 expression in human gastric cancer.

Background: Human four-and-a-half LIM domains 1 (Fhl1) gene has been reported to achieve cancer suppressive effects. The purpose of this study is to clarify clinical significance of Fhl1 expression in gastric cancer.

Methods: Fhl1 mRNA expression was quantified by real-time reverse transcription (RT)-polymerase chain reaction (PCR) using paired tumor and normal clinical samples from a total of 110 gastric cancer patients. Fhl1 protein expression was investigated by immunohistochemistry. The relationship between Fhl1 mRNA expression and clinicopathological factors was statistically analyzed.

Results: Fhl1 mRNA expression in tumor tissue was significantly downregulated compared with that in normal mucosa (P < 0.0001). Fhl1 protein expression was also diminished in cancer cells by immunohistochemistry. Kaplan-Meier survival curves demonstrated that the patients with low Fhl1 expression tumor showed significantly shorter survival (P < 0.05) than those with high Fhl1 expression tumor. Furthermore, the tumors with low Fhl1 expression showed deeper invasion into the serosal layer (P < 0.05) or more frequent distant metastasis (P < 0.01).

Conclusion: Fhl1 gene was underexpressed in clinical gastric cancer. Loss of Fhl1 expression would be a novel biomarker to determine biological aggressiveness of gastric cancer.