肺腺癌同源正常组织中差异表达基因的克隆

目的 从与肺腺癌同源的正常组织中筛选差异表达基因，以期从分子水平阐明机体抑制肿瘤发生的机制。方法 利用抑制性消减杂交分别肺癌组织及肺腺癌同源正常组织cDNA片段，并建立相应的cDNA文库。用肺腺癌组织及与其同源的正常组织cDNA片段作为探针，分别进行逆向和正向斑点杂交，筛选与同源正常组织探针杂交而不与肺腺癌组织探针杂交的阳性克隆并测序，测序结果与GenBank中的序列进行同源性分析。结果 在肺腺癌同源正常组织中，获得12个差异表达基因片段，其中4个与细胞凋亡相关基因有较高的同源性；8个与人类不同染色体的不同区域有较高的同源性，功能不详。结论 推测肺腺癌同源正常组织中存在凋亡相关基因等，它们可能通过多种途径促进细胞凋亡而抑制细胞异常增殖，从而达到抑制肿瘤发生的目的。

Cloning of differentially expressed genes in normal tissue homologized to pulmonary adenocarcinoma

Aim To explore the molecular mechanism of inhibiting tumor generation, we screen differentially expressed genes from normal tissues homologized to pulmonary adenocarcinoma. Methods cDNA fragments from normal tissue homologized to pulmonary adenocarcinoma and pulmonary adenocarcinoma tissue were obtained by suppression subtractive hybridization(SSH) respectively and corresponding cDNA libraries were established. Forward and reverse dot hybridization were carried out using cDNA fragments of homologous normal tissue and pulmonary adenocarcinoma tissue as probes. The positive clones hybridized with homologous normal tissue probe but not with pulmonary adenocarcinoma tissue probe were selected and sequenced. The results of sequencing were compared homologously with sequences in GenBank. Results 12 gene fragments of differential expression were obtained, 4 of them had high homology with cell apoptosis associated genes, 8 sequences whose functions were unknown had high homology with different regions of human different chromosomes. Conclusion It is suggested that the normal tissue homologized to pulmonary adenocarcinoma can prevent from the occurrence of tumor by promoting cellular apoptosis to inhibit abnormal cells proliferation through varied pathways.