卵巢上皮性癌血清DNA中p15、p16基因纯合性丢失及其共丢失的研究

Homozygous deletion of p15、p16 genes and its co-deletion of p15/16 genes in serum DNA of the epithelial ovarian cancer

背景与目的:p15和/或p16基因高频率的丢失与卵巢癌的发生、发展及预后关系密切,在卵巢癌组织DNA中的研究已有报道,但其在血清DNA中的丢失情况尚不清楚。本研究拟对卵巢上皮性癌、卵巢囊肿及健康对照者血清DNA中的p15、p16基因纯合性丢失及共丢失现象进行研究,探讨其与卵巢癌发生、发展的相关性。方法:采用PCR技术分别对165例卵巢上皮性癌、其相应淋巴细胞、25例卵巢囊肿及15例健康对照者血清DNA中p15/p16基因纯合性丢失及共丢失情况进行检测。结果:165例卵巢上皮性癌血清DNA中,p15、p16基因纯合性丢失率及p15/P16基因共丢失率分别为27.9%(46/165)、27.3%(45/165)及24.2%(40/165),而卵巢癌患者相应的淋巴细胞DNA与卵巢囊肿及健康对照者血清DNA中均未见丢失,差异有极显著性(P值分别为0.000、0.000及0.000)。Ⅰ、Ⅱ期卵巢上皮性癌血清DNA中,p16/p15基因共丢失率为8.6%(3/35),Ⅲ期及Ⅳ期共丢失率分别为29.3%(22/75)及27.3%(15/55),差异有显著性(P=0.049)。而p15、pl6基因丢失率与组织学类型无关。结论:p15、p16基因纯合性丢失及p15/p16基因共丢失现象与卵巢癌发生及发展相关,且可能为卵巢癌发生过程中的关键基因;采用血清DNA作为研究载体,可作为研究卵巢癌相关生物学特性的检测手段。

Background and purpose： It has been confirmed that homozygous deletion of p16/p15 gene and its codeletion of p16/p15 genes were related to the occurrence, progress and prognosis of epithelial ovarian cancer. However, the mono-deletion and co-deletion of the genes has been detected with tissue but not in serum DNA of the epithelial ovarian cancer. In this article, we studied the relationship between homozygous deletion of p16/p15 gene and its co-deletion of p16/p15 genes in serum DNA of the epithelial ovarian cancer. Methods： Primers were used to amplify exon 2 of p16 and exon 2 of p15 gene by polymerase chain reaction. Homozygous deletions of the p16, p15 and co-deletion of p16/p15 genes were studied in either serum DNA of 165 patients with epithelial ovarian cancer, their counterpart lymphocytes DNA, serum DNA of 25 benign ovarian cyst or of 15 health donors. Results： The homozygous deletion rates of either p15 or p16 gene were 27.9% （46/165）and 27.3% （45/165）serum DNA in the patients with epithelial ovarian cancer respectively, while the co-deletion rate of p16/p15 genes was 24.2% （40/165）. However, the deletions of p15/p16 genes and its co-deletion were not found in serum DNA of the counterpart lymphocytes, 25 benign ovarian cyst and 15 health donors （ The P values were 0. 000 ,0. 000 and 0.000 respectively）. The deletions of either p15 or p16 gene for the patients with stage Ⅰ～Ⅱ were 14.3% （5/35） and 11.4% （4/35）, 33.3% （25/75） and 32.0% （24/75） for the patients with stage Ⅲ, 29.1% （ 16/ 55） and 30.9% （17/55） for stage Ⅳ, respectively. Although there was no significant differences among the groups, the deletion of p15 and p16 genes in the patients with advanced stage were higher than that with early stage. The deletion was not found to be associated with histopathology of epithelial ovarian cancer. Conclusions： Homozygous deletions of the p16, p15 genes and its co-deletion of p15/p16 genes were commonly found in the serum DNA of epithelial ovarian cancer and might be associated with clinical stage of the disease. It was suggested that detection with serum DNA may be used as a micro-invasive approach and the deletion of genes might served as biological markers for the development and prognosis of the patients with epithelial ovarian cancer.