Downregulation of WDR20 due to loss of 14q is involved in the malignant transformation of clear cell renal cell carcinoma (WDR20 overexpression in RCC cell line)

Previously, we have reported that genomic loss of 14q occurs more frequently in high grade clear cell renal cell carcinomas (ccRCCs) than low grade ones and shows a significant impact on the expression levels of genes located on this region, suggesting that the genes located on the region and downregulated by the loss may be involved in the malignant transformation of ccRCCs. Here, among the genes located on the minimal common region of 14q loss, we found that 6 were significantly downregulated in high grade ccRCCs due to copy number loss. Using the data set from The Cancer Genome Atlas (TCGA) Research Network, downregulation of one out of the 6 genes, WDR20, was significantly associated with poorer prognosis for the patients with ccRCC, suggesting that downregulation of WDR20 may be involved in the malignant transformation of ccRCC. In this array study, we aimed to investigate the effect of WDR20 overexpression on the gene expression profile of an RCC cell line, 786_O. For this aim, we established 3 cell clones stably transfected with the WDR20 expressing vector (786O_WDR20cl1, 786O_WDR20cl2 and 786O_WDR20cl3) and one cell clone stably transfected with the corresponding empty vector (786O_vector) and performed expression microarray analysis using RNAs from these cell lines. In this array study, we aimed to investigate the effect of WDR20 overexpression on the gene expression profile of an RCC cell line, 786_O. For this aim, we established 3 cell clones stably transfected with the WDR20 expressing vector (786O_WDR20cl1, 786O_WDR20cl2 and 786O_WDR20cl3) and one cell clone stably transfected with the corresponding empty vector (786O_vector). RNA samples from these clonal cells were subjected to expression microarray and differentially expressed genes between control and WDR20 overexpressing cells were analyzed by GeneSpring. Average expression levels of genes in three kinds of WDR20 expressing clones (786O_WDR20cl1, 786O_WDR20cl2 and 786O_WDR20cl3) were compared with those in two replicates of the control clone (786O_vector).