ABSTRACT
<p><b>OBJECTIVE</b>To examine the correlation between the mRNA and proteins expressions of gastrin(GAS), and the association of protein expression of GAS with apoptosis index(AI) and apoptosis regulation gene Fas/FasL, caspases in colorectal cancer.</p><p><b>METHODS</b>The expressions of GAS mRNA in tumor tissues of 79 cases with colorectal cancer were detected by nested RT-PCR. Cell apoptosis was detected by molecular biology in situ apoptosis detecting technic(TUNEL). Protein expressions of GAS, Fas/FasL, and caspases were detected by immunohistochemical staining (SP method).</p><p><b>RESULTS</b>The positive correlation was found between the mRNA and proteins expressions of GAS(rGAS=0.99, P<0.01). The mRNA and protein expressions of GAS in well and moderately differentiated cancers were significantly lower than those in poorly differentiated cancers (chi(2)(high vs low)=10.47, 10.23, P<0.01, chi(2)(middle vs low)=6.68, 4.95, P<0.05). The mRNA and protein expressions of GAS in papillary and tubular adenocarcinomas were significantly lower than those in mucinous adenocarcinomas, signet-ring cell carcinoma and undifferentiated carcinoma (chi(2)(papillary vs mucinous and signet-ring)=4.80, 6.22, chi(2)(papillary vs undifferentiation)=5.44, 8.43, chi(2)(tubular vs mucinous and signet-ring)=4.40, 4.38, chi(2)(tubular vs undifferentiation)=4.92, 6.43, P<0.05, respectively). The mRNA and protein expressions of GAS in Dukes' stages A, B were significantly lower than those in Dukes stages C, D (chi(2)=4.84, 4.45, P<0.01). The AI in GAS high and moderate expression groups of colorectal cancer were significantly lower than that in low expression group (q(high vs low)=6.71, q(middle vs low)=4.60, P<0.01). The positive expression rate of FasL was significantly different among GAS high, moderate and low expression groups of colorectal cancer (chi(2)=9.35, P<0.01). The positive expression rate of FasL in GAS high and moderate expression groups was higher than that in low expression group (chi(2)high vs low=6.24, chi(2)(middle vs low)=4.74, P<0.05).</p><p><b>CONCLUSIONS</b>GAS plays an important role in the regulation of cell apoptosis in colorectal carcinoma, whose mechanism may be related to the aberrant expression of Fas/FasL. GAS will be one of the indicators of the biological behavior in colorectal carcinoma.</p>