组织蛋白酶B在结直肠癌中的表达及临床意义

Expression of cathepsin B and its clinical importance in colorectal cancer

目的探讨组织蛋白酶B(CatB)的表达与结直肠癌浸润和转移的关系及临床意义。方法采用免疫组织化学(免疫组化)法检测83例患者的结直肠癌原发灶、正常结肠黏膜、转移淋巴结和肝转移灶中CatB表达,用酶联免疫吸附法检测患者外周静脉血CatB水平。结果结直肠癌原发灶、正常结肠黏膜、转移淋巴结和肝转移灶中CatB表达阳性率分别为56.6%、31.3%、88.4%和85.0%,癌原发灶、肝转移灶和转移淋巴结中CatB表达阳性率高于正常肠黏膜组织(χ2=45.6124,P<0.01);转移淋巴结和肝转移灶中CatB表达阳性率高于癌原发灶(χ2=11.5982、4.3747,P<0.05)。DukesC、D期CatB表达阳性率高于DukesA、B期(χ2=16.9385,P<0.01),低分化腺癌和黏液腺癌CatB表达阳性率高于高、中分化腺癌(χ2=14.2338,P<0.01)。83例结直肠癌患者外周静脉血CatB平均水平为(5.9±2.9)ng/ml,30例健康志愿者CatB平均水平为(2.3±1.1)ng/ml,两者差异有统计学意义(t=6.6975,P<0.01)。DukesC、D期结直肠癌患者外周血CatB水平高于DukesA、B期患者。结论CatB增强表达与结直肠癌浸润转移有关,检测外周静脉血CatB水平对临床预测和判断淋巴结和肝转移有重要意义,有助于评价和观察临床治疗效果。

Objective To investigate the expression of cathepsin B（CatB） in colorectal cancer tissues and serum levels of CatB in patients with colorectal carcinoma and to study the association of CatB expression with lymph node and liver metastasis. Methods Immunohistochemistry was used to detect CatB expression in tissues, and enzyme linked immunosorbent assay was applied to test CatB levels in peripheral vein blood in 83 patients with colorectal cancer. Results The expression rates of CatB in primary leisons, normal colon mucosa, lymph node metastases and hepatic metastases were 56.6%, 31.3%, 88.4%, 85.0% respectively. The positive rates of CatB in primary leisens, hepatic and lymph node metastases were higher than that in normal mucosa（χ^2 =45. 6124, P 〈0. 01）. The CatB expression rates in lymph node and hepatic metastases were higher than that in primary leisons（x^2 = 11. 5982,4. 3747, P 〈0. 05）. The positive rate of CatB was higher in Dukes＇ C and D tumors than that in Dukes＇A and B tumors（x^2 = 18. 8871, 25. 1650, P 〈0.01 ）, higher in poorly differentiated and mucous adenocarcinomas than that in well-moderately differentiated adenocarcinomas（x^2 = 14. 2338, P 〈0. 05） . The mean serum level of CatB in 83 patients with colorectal cancer was （5.9 ± 2.9） ng/ml, higher than （2.3 ± 1.1 ） ng/ml in the controls of 30 healthy volunteers（ t = 6. 6975, P 〈0. 01 ）. The serum level of CatB in the patients with Dukes C, D stages were higher than that with Dukes A, B stages. Conclusions Enhanced expression of CatB in colorectal cancer tissues is associated with tumor infiltration and metastasis. Monitoring serum CatB level in patients with colorectal cancer is important in the prediction and diagnosis of lymph node and hepatic metastasis, and valuable for evaluation of the therapeutic effect.