中文摘要：

目的探讨p16表达与胃癌细胞的增殖能力、胃癌的临床特征及胃癌患者预后的关系。方法采用逆转录聚合酶链反应（RT-PCR）、免疫组化和Western blot方法，检测胃癌细胞系SGC-7901、MKN45、MKN28和65例胃癌组织标本中p16mRNA和蛋白的表达。以AdCMV—p16感染胃癌SGC-7901细胞，采用四甲基偶氮唑蓝（MTT）法测定感染前后SCC-7901细胞存活率的变化，采用流式细胞术检测感染前后SGC-7901细胞细胞周期的变化。比较不同p16表达状态胃癌患者的术后生存情况。结果胃癌细胞系MKN45呈p16弱阳性表达，SGC-7901和MKN28细胞系呈阴性表达。以20PFU／细胞感染腺病毒AdCMV-p16时，原本p16阴性表达的SCC-7901细胞中p16表达转为阳性。转染p16的SGC-7901细胞存活率下降，G。期细胞比例上升，S期细胞比例下降。65例胃癌组织中，p16阳性率为32．3％，明显低于正常胃黏膜组织（81．5％），且p16表达与胃癌的分化程度、淋巴结转移有关。p16阴性组的胃癌患者无瘤生存期明显缩短。结论p16基因对胃癌细胞增殖的调控至关重要，p16的失活赋予了胃癌细胞高增殖、转移活性，并导致了胃癌患者的无瘤生存期缩短。

英文摘要：

Objective To investigate the relationship between p16 expression and cell proliferation and prognosis in gastric cancer patients. Methods Gastric cancer cell lines SGC-7901, MKN45, MKN28, human embryonic kidney cell line HEK293, human fibroblast cell line MRC-5, and surgical specimens of gastric carcinoma and adjacent normal gastric mucasa from 65 patients were included in this study. RT-PCR, MTI＂ and FCM assays were used to detect p16 expression in gastric cancer cell lines and surgical specimens of gastric cancer. MTr assay was used to determine cancer cell viability and FCM to detect cell cycle. Kaplan-Meicr survival curve and Log-Rank statistics were used to analyze the relationship between p16 expression and survival of potients with gastric cancer. Results Gastric cancer cell lines were mostly negative for p16 expression, and p16 was re-expressed after the cells transfected with p16 gene by adenovims AdCMV-pl6. p16 re-expression resulted in the decrease of cancer cell viability and cancer cell cycle arrest with increased Gl phase and decreased S phase, p16 expression in cancer specimens was 32.3% （21/65）, significantly lower than the 81.5% （ 53/65 ） in normal mucosa （X2 = 32.124, P 〈 0. 001 ）. The disease-rice survival was significantly shorter in pl6-negative patients than that in pl6-positive patients （P 〈 0.01 ）, but not the overall survival （ P 〉 0.05 ）. p16 expression was significantly correlated with differentiation and lymph node metastasis, but not significantly correlated with sex, age, tumor size or invasion depth of the gastric cancer. Conclusions p16 gene is important for cancer cell proliferation. The inactivation gives cancer cells a high activity for proliferation and metastasis, and then influences the disease-free survival of gastric cancer patients.