Identification of high risk group for prostate cancer by investigation of vitamin D receptor gene

首先，采用PCR-RFLP方法检测了健康志愿者和前列腺癌、其他癌症、尿石症患者维生素D受体基因第8内含子和第8外显子之间的单核苷酸多态性（single nucleotide polymorphism，SNPs）。3个酶切位点分别为ApaI、BamHI和TaqI。101例对照样本的TaqI基因型为TT（74.3%）、Tt（24.8%）和tt（1.0%），BamHI基因型为BB（4.0%）、Bb（27.7%）和bb（68.3%），ApaI基因型为AA（11.9%）、Aa（43.6%）和aa（44.6%）。在尿石症患者中，t等位基因是尿石症复发的危险因素。其次，对40例肾细胞癌进行了6号染色体缺失定位。分析了从D 6S 975到D 6S 1577的6个微卫星标记，位于6 q，22.3cM。40例中有13例（33%）在5个标记物中至少有1个存在洛丢失。在洛缺失的病例中，D 6S 311位点的17.1 cM区域和/或D 6S 441位点的9.8 cM区域的洛最常见。在同一分析中，前列腺癌病例中未观察到显著结果。第三，采用PCR-SSCP技术对BRG 1基因进行突变分析。BRG 1基因位于19 p，在前列腺癌中常见缺失。BRG 1基因第9外显子存在基因型变异。直接测序显示T/T、T/C、C/C的SNP 33978。SNP 33978 T/T基因型患者的确诊年龄明显较低（p=0.03）。年轻患者（<62岁）T/T基因型较T/C或C/C基因型更易发生高级别、晚期和转移性肿瘤（p=0.0134）。分析生殖系SNPs的变异及其组合对癌症的预防、治疗方案的制定和预后的预测具有重要意义。

Firstly, single nucleotide polymorphisms (SNPs) of vitamin D receptor gene were examined using three PCR-RFLP markers spanning between intron 8 and exon 8 in the healthy volunteers and the patients with urological problems including prostate cancer, other cancers and urolithiasis. Three restriction sites were ApaI, BamHI and TaqI. Genotypes in 101 of control samples were, TT (74.3%), Tt (24.8%) and tt (1.0%) for TaqI, BB (4.0%), Bb (27.7%) and bb (68.3%) for BamHI, AA (11.9%), Aa (43.6%), and aa (44.6%) for ApaI. In the patient with urolithiasis, t allele was indicated as a risk factor for the recurrent disease. Secondly, deletion mapping of chromosome 6 in 40 cases of renal cell carcinoma was performed. Six microsatellite markers on 6q, 22.3 cM from D6S975 to D6S1577 were analyzed. 13 cases out of 40 (33%) were found to have LOH at least one out of 5 markers. Among the cases with LOH, LOH in the 17.1 cM region with D6S311 and/or the 9.8 cM region with D6S441 were frequently observed. No remarkable findings were seen in prostate cancer cases in the same analysis. Thirdly, mutation analysis of BRG1 gene using PCR-SSCP was performed. BRG1 gene is located at 19p where deletion is frequently seen in prostate cancer. Variation of the genotype of BRG1 gene was observed in exon 9. Direct sequencing revealed SNP33978 of T/T, T/C, C/C. The patients with T/T genotype of SNP33978 were diagnosed at significantly younger ages (p=0.03). Young patients (age<62 years) with T/T genotype were more frequently to have high grade, advanced stage and metastatic tumors than patients with the T/C or C/C genotype (p=0.0134). It was suggested to be useful in preventive medicine, in decision making of therapeutic options and in predicting prognosis patients with cancer to analyze the variation and the combination of several germline SNPs.