HLCDG1基因转染对肺癌细胞生长的影响

Effect of HLCDG1 Gene Transfection on Growth of Lung Carcinoma Cells

背景与目的:HLCDGI基因是我们实验室最近克隆的新基因,它位于5q33,介于D5S436～D5S470之间,在肺癌组织中明显表达下调或缺失。本研究旨在观察HLCDGI基因是否具有抑制肺癌细胞生长的能力。方法:构建HLCDGI基因的重组质粒pcDNA3.1(+)/HLCDGI,通过脂质体转染,将HLCDGI基因cDNA导入肺癌细胞系A549中,经G418筛选,获得稳定表达的细胞克隆。RT-PCR检测HLCDGI基因表达,并采用细胞生长抑制实验、软琼脂集落形成实验及裸鼠致瘤性实验,分析HLCDGI基因转染细胞恶性表型。结果:RT-PCR结果表明转染HLCDGI 基因的细胞HLCDGI mRNA明显表达。转染HLCDGI基因组、转染空载体组和未转染组,3组细胞生长倍增时间分别为70.0 h、43.3 h和39.5 h,转染HLCDGI基因组与两对照组之间的差异有显著性(P<0.05)。计算软琼脂中细胞克隆形成率,结果分别为8.5％、29.0％和35.0％,转染HLCDGI基因的细胞克隆形成率明显降低。将转染HLCDGI基因的细胞、转染空载体的细胞和未转染的细胞分别注射入无胸腺的裸鼠体内,43天后处死动物,剥离出肿瘤组织并称重,各组瘤块平均重量分别为0.120g、0.612g和0.924g,转染HLCDGI基因的细胞成瘤能力与两对照组细胞比较,差异有显著性(P<0.05)。结论:HLCDGI在肺癌A549细胞中表达。

BACKGROUND & OBJECTIVE: HLCDG1, which locates in chromosome 5q33 (between D5S436 and D5S470), is a novel gene that our laboratory has cloned recently. The expression of HLCDG1 gene was significantly down-regulated or deleted in the primary lung carcinoma. This study was designed to observe if HLCDG1 has the potential to suppress growth of lung carcinoma cells. METHODS: The recombinant plasmid, pcDNAS. 1(+)/ HLCDG1, was constructed and subsequently transfected into A549 cells through liposome transfection. The A549 cells stably expressing HLCDG1 gene were established by G418 selection. RT-PCR was used to demonstrate the expression of HLCDG1 gene. Furthermore, the cell proliferation assay, the soft agar assay, and the tumorigenesis assay were used to analyze the malignant phenotype of the HLCDG1-transfected cells. RESULTS: The HLCDG1-transfected cells exhibited the expression of HLCDG1 mRNA by RT-PCR. The population double time (PDT) of HLCDG7-transfected group, vector-transfected group, and nontransfected group were 70.0 hours, 43.3 hours, and 39.5 hours, respectively; the difference between HLCDG1 -transfected group and the other two groups was significant ( P < 0. 05). The colony formation rates of HLCDG1-transfected group, the vector-transfected group, and nontransfected group were 8.5% , 29.0% , and 35.0% , respectively. The rate of HLCDG1-transfected cells was markedly lower than those of the other two groups ( P <0. 05). Moreover, these clones were injected into athymic nude mice. After 43 days, they were killed, and their tumors were isolated. These tumors weighed 0. 120g, 0. 612g, and 0. 924g, respectively. CONCLUSION: The expression of HLCDG1 in A549 cells may have the potential to suppress tumor cell growth and the tumorigenesis of A549 cells transplanted in nude mice. These results suggested that HLCDG1 gene might be a good candidate of tumor suppressor gene correlated with lung carcinoma.