衰老标志物在大肠腺瘤和大肠癌中的表达及意义

The expression and clinical significance of senescence markers in colorectal adenoma and colorectal cancer tissues

目的探讨衰老标志物衰老相关β半乳糖苷酶(SA-β-gal)及P16^(INK4A)在大肠腺瘤及大肠癌中的表达及其临床意义。方法应用SA-β-gal染色法和免疫组织法分别检测30例大肠腺瘤及腺瘤旁正常组织、48例大肠癌组织及癌旁组织中SA-β-gal及P16^(INK4A)的表达。分析和比较不同病理特征的大肠腺瘤及大肠癌中SA-β-gal和P16^(INK4A)的表达情况。结果大肠腺瘤组织中SA-β-gal和P16^(INK4a)的表达明显高于大肠癌组织及腺瘤旁正常组织,大肠癌组织中SA-β-gal和P16^(INK4a)的表达明显低于癌旁正常组织。SA-β-gal在绒毛管状腺瘤、>1 cm的腺瘤、进展期腺瘤中低表达,在低分化腺癌、有远处转移、Ⅳ期的大肠癌中低表达。P16^(INK4a)在无淋巴结转移、Ⅰ、Ⅱ期大肠癌中高表达。结论 SA-β-gal及P16^(INK4a)在不同大肠组织中的表达情况提示细胞衰老可能作为抑制途径参与到腺瘤发生癌变的过程中。推测SA-β-gal的检测可能作为预警高风险癌前病变的标志物,P16^(INK4a)可作为大肠癌预后良好的指标。

Objective To investigate the expression of the senescence markers, including the senescence -asso- ciated β galactosidase （ SA - β - gal） and P16INK4a, in colorectal adenoma and colorectal cancer tissues, as well as their clinical significance. Methods SA -β - gal staining and immunohistochemical staining was used to evaluate the expres- sion of SA -β - gal and P16INK4a in 30 cases of paired colorectal adenoma and normal tissues, 48 cases of paired colorectal cancer and normal tissues. The expression of SA -β-gal and P16INK4a in different pathological characteristics of colorectal adenomas and coiorectal cancer were analyzed. Results The expression of SA - β - gal and P16INK4a in colorectal adeno- ma tissues was significantly higher than the colorectal cancer tissues and normal tissues adjacent to adenoma, and the ex- pression of SA -β - gal and P16INK4a in the colorectal cancer tissues was significantly lower than normal tissues adjacent to cancer. The expression of SA β - gal was low in the villioustublar adenoma, the colorectal adenoma with 〈 1cm size, and advance adenoma. The expression of SA - β - gal was also low in low differentiated adenocarcinoma, the colorectal with distant metastasis, and the Stage IV colorectal cancer. The expression of P16INK4a was high in the colorectal cancer without lymph node metastasis, and Stage I and II colorectal cancer. Conclusion The expression of SA -β - gal andP16INK4a show that senescence may be as inhibition pathway involved in the process of the colorectal adenoma turning into cancer. The detection of SA - β - gal is supposed to be a marker to find high - risk precancerous lesions, and P16INK4a is supposed to be as application indicating good prognosis.