Study On Expression And Function Of KLK6 In Breast Tissue And Cell

KLK6(neurosin/zyme/protease) is a new member of the human kallikrein genefamily, which consists of enzymes with serine protease enzymatic activity. Recentreports have implicated KLK6 in ovarian cancer. It may have potential clinical value fordisease diagnosis or prognosis and it may also be a useful therapeutic target. In thisstudy, to verify the function of KLK6 in breast cancer by examining KLK6 geneexpression in normal and cancerous breast tissues and cell lines.Objectives: To investigate KLK6 expression levels in tumor tissues andnormal tissues by developing a real time quantitative PCR method and analyze thecorrelation between KLK6 expression levels in tumor tissues and other pathologicalparameters, such as estrogen receptor, progesterone receptor, tumor metastasis andCerbB-2. To observe variation of cell morphology, cell cycle and apoptosis whenKLK6 gene expression was interfered in breast cancer cell line MCF-7.Methods: KLK6 mRNA copies were absolutely quantified in 33 tumors tissue andpaired normal tissues using SYBR Green I as reporter dye, GAPDH as inner referencegene and recombined plasmid as standcurve template. The correlation between KLK6expression and several pathological parameters was analyzed by t test. In addition,KLK6 expression in vitro was interfered by chemical synthetic siRNA, the interferenceresults was analyzed by FQ-PCR and flow cytometer.Results: The amplification efficiencies for GAPDH and KLK6 of the real-timequantitative PCR method were both 100%. Inter-coefficient of variability was 0.8%and 2.0%; intra--coefficient of variability were 3.9% and 3.2% respectively.KLK6 was overexpression in tumor tissues. High KLK6 expression was foundmore frequently in node-negative (p<0.01), estrogen receptor-negative (p=0.005)patients. T test did not show significant difference between either progesteronereceptor or CerbB-2 negative subgroup and positive subgroup. When KLK6 expressionwas interfered, it was found that S phase fraction in cell cycle increased 11.13%, cellmorphology and apoptosis had no significance variation.