p73和p51基因在结直肠癌中的表达和意义

Expressions and Significance of p73 and p51 Genes in Colorectal Cancer

背景:p53基因是一种肿瘤抑制基因,其家族成员p73和p51在结构上与p53具有高度同源性,影响细胞转录和凋亡的功能与p53相似。目的:研究p73和p51基因在结直肠癌中的表达及其与细胞凋亡和肿瘤临床病理特征的关系,探讨两者在结直肠癌发生、发展中的可能作用。方法:以逆转录聚合酶链反应(RT-PCR)检测60例结直肠癌组织和相应癌旁组织中p73、p51mRNA表达,以原位末端标记(TUNEL)法检测细胞凋亡。结果:结直肠癌组织p73、p51AmRNA表达阳性率显著高于相应癌旁组织(p73:71.7%对5.0%,P<0.01;p51A:46.7%对11.7%,P<0.01);p51BmRNA在结直肠癌组织与相应癌旁组织中的相对表达量无明显差异(0.7318±0.3628对0.6836±0.3516,P>0.05)。p73、p51AmRNA表达阳性者肿瘤细胞凋亡指数分别显著低于p73、p51AmRNA表达阴性者(p73:3.2%±2.5%对5.5%±2.8%,P=0.003;p51A:2.6%±2.3%对4.9%±2.7%,P=0.001)。p73mRNA表达与结直肠癌的分化程度、TNM分期和淋巴结转移相关(P<0.05),p51AmRNA表达仅与淋巴结转移相关(P<0.05)。结论:结直肠癌中p73、p51A基因表达上调,两者可能通过抑制肿瘤细胞凋亡而参与了结直肠癌的发生、发展。p73过表达可能与结直肠癌预后不良有关。

Background： p73 and p51 genes are members of p53 tumor suppressor gene family, which share considerable structural homologies with p53, and their transcriptional and apoptotic function are similar to those of p53. Aims： To investigate the relationships between expressions of p73 and p51 genes in colorectal cancer, tumor cell apoptosis and patients＇ elinicopathologic characteristics, so as to clarify the potential roles of p73 and p51 in the development and progression of colorectal cancer. Methods： Expressions of p73 and p51 mRNA in 60 colorectal cancerous tissues and matched paraeancerous tissues were determined by reverse transcriptase polymerase chain reaction （RT-PCR）, and tumor cell apoptosis was detected by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling （TUNEL） method. Results： The positivity rates of p73 and p51A mRNA in coloreetal cancerous tissues were significantly higher than those in matched paracancerous tissues （p73： 71.7% vs. 5.0%, P〈0.01; p51A： 46.7% vs. 11.7%, P〈0.01）, whereas the relative expression levels of p51B mRNA between coloreetal cancerous tissues and the matched paracaneerous tissues were not statistically different （0.7318±0.3628 vs. 0.6836±0.3516, P〉0.05）. The apoptotie indices of tumor cells in p73 mRNA- and p51A mRNA-positive cancerous tissues were significantly lower than those in p73 mRNA- and p51A mRNA-negative ones, respectively （p73： 3.2%±2.5% vs. 5.5%±2.8%,P=0.003; p51A： 2.6%±2.3% vs. 4.9%±2.7%, P=0.001）. p73 mRNA expression was correlated with differentiation, TNM stage and lymph node metastasis of eoloreetal cancer （P〈0.05）, while p51A mRNA expression was only correlated with lymph node metastasis （P〈0.05）. Conclusions： Expressions of p73 and p51A genes are upregulated in eolorectal cancer, which might be involved in the development and progression of colorectal cancer via inhibiting tumor cell apoptosis, p73 overexpression might be correlated with the poor prognosis of colorectal cancer.