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

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

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,G1 15例(19% ),G2 56例(73% ),G3 6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。

Objective To evaluate the e xp ression of hypoxia inducible factor( HIF)-1α、2α in sporadic clear cell re nal cell carcinoma and their relationships to the mutations of von Hippel-Linda u(VHL) gene. Methods Mutations of VHL gene, expression of HIF-1α and 2α were detected b y polymerase chain reaction (PCR), direct DNA sequencing and immunohistochemistr y in 77 cases of Chinese sporadic clear cell renal cell carcinama (CCRCC). The stage was pT 1N 0M 0 in 55 patients (71%), pT 2N 0M 0 in 7 patients (9%), pT 3N 0M 0 in 14 patients (18%), and pT 4N 0M 0 in 1 patient (1%). The cl assification 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 t umor nuclear grade 3. Results None of the VHL gene mutations were found in all the normal tissue sp ecimens. VHL gene mutations were detected in 40 (52%) cases of CCRCC. The posit ive rate of HIF-2α (81%) was higher than that of HIF-1α (66%)(χ~2=23.310 , P<0.01); The positive rate of HIF-1α and HIF-2α in the cases of mu tations(98% and 93% respectively) was higher than that of them in non-mutations (32% and 68% respectively)( χ~2=36.386,7.617,P<0.01); The correlat ion between HIF-1α and VHL gene mutations was closer than that between HIF-2 α and VHL gene mutations (partial correlation coefficiency was 4.481 and 2.02 7 respectively,P<0.01). The expression of HIF-1α and 2α in different pa thological grade and stage of CCRCC showed no significant difference( P>0.0 5).Conclusions Our study suggests that VHL gene mutations are frequent in sporadic C CRCC, and the high expression of HIF-1α and 2α are found in the group of VHL mutations. However, we have not found significant correlation between the expre ssion of HIF-1α and 2α and pathological grade and stage of CCRCC in our study .