散发性肾透明细胞癌组织中希佩尔-林道基因突变与缺氧诱导因子1α、2α的测定

目的探讨散发性肾透明细胞癌(CCRCC)组织中希佩尔-林道(VHL)基因突变、缺氧诱导因子1α(HIF-1α)和HIF-2α的表达及其关系,对肿瘤分期、分级的影响.方法应用聚合酶链反应(PCR)、PCR产物直接测序和免疫组化等方法,分析77例散发性CCRCC患者癌组织中VHL基因突变、HIF-1α和HIF-2α的表达.其中T1期 55例(71%),T2期7例(9%),T3期14例(18%),T4期1例(1%);病理分级,G115例(19%),G256例(73%),G36例(8%).结果在正常肾组织中无VHL基因突变.散发性CCRCC中VHL基因突变率为52%(40/77),HIF-2α阳性率81% (62/77),高于HIF-1α阳性率66%(51/77)(χ2 =23.310, P<0.01);VHL基因突变者中HIF-1α和HIF-2α的阳性率(98%和93%)均高于无突变者的阳性率(32% 和68%,χ2值分别为36.386,7.617,P均<0.01);HIF-1α和HIF-2α的表达均与VHL基因突变相关(偏回归系数分别为4.481,2.027,P均<0.01);未发现VHL基因突变、HIF-1α和HIF-2α表达与肿瘤病理分级、分期有关(P均>0.05).结论在散发性CCRCC患者中VHL基因突变较广泛,在突变组织中HIF-1α和2α高表达,但VHL基因突变、HIF-1α和2α的表达与患者病理分级、分期不相关.

The expression of hypoxia inducible factor-1,2 alpha in sporadic clear cell renal cell carcinoma and their relationships to the mutations of von Hippel-Lindau gene

OBJECTIVE: To evaluate the expression of hypoxia inducible factor (HIF)-1alpha, 2alpha in sporadic clear cell renal cell carcinoma and their relationships to the mutations of von Hippel-Lindau (VHL) gene. METHODS: Mutations of VHL gene, expression of HIF-1alpha and 2alpha were detected by polymerase chain reaction (PCR), direct DNA sequencing and immunohistochemistry in 77 cases of Chinese sporadic clear cell renal cell carcinoma (CCRCC). The stage was pT(1)N(0)M(0)in 55 patients (71%), pT(2)N(0)M(0) in 7 patients (9%), pT(3)N(0)M(0) in 14 patients (18%), and pT(4)N(0)M(0) in 1 patient (1%). The classification according to the tumor nuclear grading system showed 15 carcinomas (19%) of tumor nuclear grade 1, 56 (73%) of tumor nuclear grade 2 and 6 (8%) of tumor nuclear grade 3. RESULTS: None of the VHL gene mutations were found in all the normal tissue specimens. VHL gene mutations were detected in 40 (52%) cases of CCRCC. The positive rate of HIF-2alpha (81%) was higher than that of HIF-1alpha (66%) (chi(2) = 23.310, P < 0.01); The positive rate of HIF-1alpha and HIF-2alpha in the cases of mutations (98% and 93% respectively) was higher than that of them in non-mutations (32% and 68% respectively) (chi(2) = 36.386, 7.617, P < 0.01); The correlation between HIF-1alpha and VHL gene mutations was closer than that between HIF-2alpha and VHL gene mutations (partial correlation coefficiency was 4.481 and 2.027 respectively, P < 0.01). The expression of HIF-1alpha and 2alpha in different pathological grade and stage of CCRCC showed no significant difference (P > 0.05). CONCLUSIONS: Our study suggests that VHL gene mutations are frequent in sporadic CCRCC, and the high expression of HIF-1alpha and 2alpha are found in the group of VHL mutations. However, we have not found significant correlation between the expression of HIF-1alpha and 2alpha and pathological grade and stage of CCRCC in our study.