Absence of FHIT expression is associated with apoptosis inhibition in colorectal cancer

Objective To investigate the expression of fragile histidine triad (FHIT) protein in normal colorectal tissue, colorectal adenoma and colorectal cancer (CRC), and to study the relationships between the expression of FHIT protein and the clinical pathology, the apoptosis-associated protein (Bcl-2, Bax, Survivin), apoptosis in colorectal cancer. Methods Tissue microarray (TMA) and immunohistochemistry SP were used to detect the expression of FHIT gene, Bcl-2, Bax and Survivin in 16 cases of the normal colorectal tissue, 16 cases of colorectal adenoma and 80 cases of the colorectal cancer. TUNEL was used to detect the apoptosis index (AI) in 80 cases of the colorectal cancer. Results (1) The positive rates of FHIT gene expression in normal colorectal tissue, colorectal adenoma and adenocancer were 93.75%, 68.75% and 46.25% respectively. There were no significant differences in the relationships between the FHIT gene expression and histological types, the gender as well as the age ( P >0.05). There were significant relationships between FHIT gene expression and lymph node metastasis, histological grades, Duke’s system as well as the 5-year survival rate after operation. (2) The positive rates of Bax, Bcl-2 and Survivin in colorectal adenocancer were 72.50%, 51.25%, 77.50% respectively. The expression of FHIT gene was positively correlated with that of Bcl-2, Bax and Survivin. (3) The mean AI in FHIT negative tumors was significantly lower than that in FHIT positive tumors ( P <0.01). Conclusion FHIT gene may play a role in the oncogenesis and progression of colorectal cancer. The abnormal regulation of apoptosis may play an important role in the pathogenesis of colorectal cancer.