Expression Of FHL Family And EYA2 In Lung Cancer: A Clinical And Experimental Study

Four and a half LIM domain (FHL) proteins are composed of the five members FHL1, FHL2, FHL3, FHL4 and FHL5 (ACT) , and belong to the LIM-only protein subclass. They are expressed in a cell-and tissue-specific manner. It has been proved that FHL is an important regulatory factor in cell growth and differentitation by participating in transcriptional regulation, signal transduction, apoptosis and so on. Lung cancer is a leading cause of cancer deaths among men and women in the world. The objectives of this study were as follows: 1. to evaluate expression of FHL1 protein in lung cancer and investigate the mechanism of contribution of carcinogenesis of FHL1; 2. to detect expression of FHL3 protein in lung cancer; 3. to identify expression of EYA2 protein in lung cancer.Methods1. The tissues specimens from patients with primary lung cancer were obtained during surgery and were submitted to Western blotting and immunohistochemical(IHC) investigation of FHL1 and FHL3 expression. Clinicopathologic parameters were collected and subsequent correlation with FHL1 expression was analyzed. EYA2 was also detected by MC in samples of lung cancer and nonneoplastic tissues. 2. FHL1 and FHL3 expression were examined by Western blotting in four cell lines of lung cancer. 3. Transfection was performed in cell lines of lung cancer by method of positive ion liposome, and clones of FHL1 Overexpression and RNAi knock-down were screened. 4. correlation was analyzed between FHL1 expression and expression of p53, Ki67 and pl6 in lung cancer.Results1. The expression of FHL1 was found in the cytoplasm and nucleus of the tumor cells. FHL1 expression in neoplastic tissues significantly reduced compared to normal lung tissues, which was correlated with pathologic type and histological differentiation level of tumor. Compared to other pathologic types, BAC has higher level of FHL1 expression. FHL1 expression in high and moderate differentiation was more strong than that in low differentiation.2. High expression of FHL1 was observed in H1299, but no expression in A549, Calu-3, H460 and MRC-5( human embryo lung cell). Positive stable clone was not obtained by transfection experiment and screening clones of FHL1 Overexpression and RNAi knock-down in H1299 and A5493. The expression of FHL1 was not correlated with expression of p53, Ki67 and p16 in lung cancer, p53,Ki67 expression in squamous cell carcinoma were higher than that in adenocarcinoma. The expression of p16 was correlated with pTNM stage.4. The expression of FHL3 in tissue of lung cancer was correlated with gender and pathologic type, but not correlated with age, pTNM stage, histological differentiation and lymph node metastasis. FHL3 expression was up-regulated significantly in adenocarcinoma compared to normal lung tissue. In addition, FHL3 is overexpressed in cell lines of lung cancer Calu-3 and H1299.5. The expression of EYA2 in tissue of lung cancer was increased. The expression was correlated with histological differentiation and not correlated with pathologic type, pTNM stage and lymph node metastasis.Conclusions1. The expression of FHL1 was reduced significantly in lung cancer, suggesting that FHL1 might play a role in lung cancer as anti-oncogene. The expression of FHL1 was not correlated with expression of p53 and pl6 in lung cancer, but it can not be excluded that they interact with each other.2. The expression of FHL3 in lung cancer was augmented and it might be activator of transcriptional activity involved in lung cancer.3. The expression of EYA2 in tissue of lung cancer was increased. EYA2 is likely a member of oncogenes.