NKG2 D和分泌型MICA在胰腺癌组织中的表达及其临床意义

摘要

Objective To investigate the expression and clinical significances of NK cell activating receptor (NKG2D) and secreted MHC class I chain-related A (MICA) in pancreatic cancer. Methods Immunohistochem-istry was used to detect the expressions of NKG2 D and secreted MICA in tomor tissues and adjacent non-tomor tis-sues from a total of 70 patients with pancreatic carcinoma. The correlation of NKG2D and secreted MICA was ana-lyzed. The relationships between NKG2D and secreted MICA expressions and clinicopathological parameters were e-valuated. Results The positive expression rates of NKG2D and secreted MICA were 32. 9% (23/70) and 67. 1%(47/70) in pancreatic carcinoma tissues , and 60. 0% (42/70) and 31. 4% (22/70) in paracarcinoma tissues, respectively, both with statistical significance(P<0. 05). The expressions of NKG2D and secreted MICA were sig-nificantly correlated with tumor differentiation, nerve invasion, lymph node metastasis and TNM staging in pancre-atic carcinoma tissues (P<0. 05). However, there was no obvious association between NKG2D or secreted MICA and age, gender, tumor location, or tumor size. NKG2D expression was negatively correlated with secreted MICA expression in pancreatic carcinoma tissues ( P <0 . 05 ) . Conclusion Down-regulated NKG2 D and up-regulated secreted MICA are significantly correlated with the infiltrative capability in pancreatic carcinoma. NKG2D and se-creted MICA have a negative correlation in pancreatic carcinoma tissues, which reveals that secreted MICA may in-hibit the level of NKG2D expression during tumor progression, thereby reducing the immune responses against tumor cells in patients with pancreatic carcinoma.%目的：研究NK细胞活化性受体( NKG2D)及其分泌型主要组织相容性复合体I类相关基因A( MICA)在胰腺癌和癌旁组织中的表达及其临床意义。方法通过免疫组织化学方法检测70例胰腺癌组织和癌旁组织中NKG2D及分泌型MICA表达情况，并分析两者之间的关系及与临床病理因素之间的关系。结果 NKG2D和分泌型MICA在胰腺癌组织中的阳性表达率为32．9%(23/70)和67．1%(47/70)；而在癌旁组织中的阳性表达率为60．0%(42/70)和31．4%(22/70)；差异均有统计学意义(P<0．05)。 NKG2D、分泌型MICA在胰腺癌组织中的表达与肿瘤分化程度、神经侵犯、淋巴结转移和TNM分期显著相关( P<0．05)，而与年龄、性别、肿瘤病变部位及大小均无关。 NKG2D的表达与分泌型MICA的表达呈负相关性(P<0．05)。结论 NKG2D的表达与分泌型MICA的表达呈显著相关性，与胰腺癌侵袭转移能力有关，分泌型MICA可能通过下调NKG2D在肿瘤中的表达，从而逃避机体对肿瘤的免疫应答。