Impact of cyclooxygenase-2 gene expression on tumor invasiveness in a human renal cell carcinoma cell line.

Purpose: We have previously confirmed that cyclooxygenase-2 (COX-2) is expressed in a human renal cell carcinoma (RCC) cell line and it has an important role in cell tumorigenesis and angiogenesis. In the current study we evaluated the impact on cell adhesion and tumor invasiveness in human RCC cell lines by transfection of COX-2 sense and antisense cDNAs.

Materials And Methods: A human RCC cell line that expresses COX-2 was transfected with COX-2 sense or antisense cDNA. E-cadherin expression in parental cells of OS-RC-2 and transfectants was detected by real-time polymerase chain reaction and Western blotting. The expression of beta-catenin was detected by Western blotting. Zymography was used to detect gelatinase activity. CD44 expression in parental cells and transfectants was detected by fluorescence activated cell sorting. Cell adhesion was detected by adhesion assay and cell invasive ability was detected by invasion assay.

Results: E-cadherin expression was increased in antisense transfectants and decreased in sense transfectants compared with parental cells at the mRNA and protein levels. However, obvious consistent changes in beta-catenin expression could not be confirmed in parental cells and transfectants, nor were there any significant differences in gelatinase activity in parental cells and transfectants. CD44 expression was increased in sense transfectants and decreased in antisense transfectants compared with parental cells. Adhesion to hyaluronan coated wells was significantly enhanced in sense transfectants and inhibited in antisense transfectants compared with parental cells. Compared with parental cells invasive ability was significantly increased in sense transfectants and decreased in antisense transfectants.

Conclusions: The results demonstrate that COX-2 expression has a crucial role in cell invasion ability and the suppression of COX-2 expression might regulate adhesion molecule expression and inhibit invasive ability in the RCC cell line OS-RC-2.