Expression of a tumor-associated gene, LASS2, in the human bladder carcinoma cell lines BIU-87, T24, EJ and EJ-M3

Abstract

Homo sapiens longevity assurance homolog 2 of yeast LAG1 (LASS2), a metastasis suppressor gene of human cancer, is the most abundantly expressed member of the ceramide synthase gene family. Expression of LASS2 has been reported in carcinomas of the prostate, liver and breast. However, there has been no report on the expression of LASS2 in human bladder cancer cell lines. In order to investigate the expression and potential role of this new tumor metastasis supressor gene in human bladder cancer, we compared the proliferation, metastasis and invasion among the BIU-87, T24, EJ and EJ-M3 human bladder cancer cell lines. The mRNA expression levels of the LASS2 gene were examined using real-time quantitative PCR (qPCR). The expression levels of LASS1 and LASS3 mRNA were used as references. The protein expression level of the LASS2 gene was detected using western blotting. The most aggressive of these four human cancer cell lines was observed to be EJ-M3. The expression of LASS2 mRNA was significantly correlated with diverse proliferation, metastasis and invasion. The expression levels of LASS1 and LASS3 mRNA were not correlated with these parameters. At the protein level, we observed that the more aggressive the cancer cell line, the lower the LASS2 protein expression level. Therefore, LASS2 expression may be correlated with the development and progression of human bladder cancer and may be a prognostic indicator for this cancer.

Keywords: Homo sapiens longevity assurance homolog 2 of yeast LAG1; biological characteristics; bladder cancer; expression.

Figure 1.

Growth curves of BIU-87, T24, EJ and EJ-M3 cells. The EJ-M3 cell proliferation was the fastest (P<0.001, vs. BIU-87, T24 and EJ) and BIU-87 cell proliferation was the slowest (P<0.05 vs. T24, EJ and EJ-M3).

Figure 2.

Numbers of EJ-M3, EJ, T24 and BIU-87 cells that attached to the lower side of the membrane. (^*P<0.05, vs BIU-87, T24 and EJ).

Figure 3.

Invasion assay. (A) EJ cells invasion, ×100 magnification; (B) EJ cells invasion, ×200 magnification.

Figure 4.

Numbers of EJ-M3, EJ, T24 and BIU-87 cells that invaded into the 24-well plates (^*P<0.001, vs. BIU-87, T24 and EJ).

Figure 5.

LASS1, LASS2 and LASS3 mRNA expression analysis. LASS1, LASS2 and LASS3 mRNA expression of BIU-87, EJ-M3, T24 and EJ cells was detected by quantitative real-time PCR.

Figure 6.

LASS2 protein expression analysis. LASS2 protein expression of BIU-87, EJ-M3, T24 and EJ cells was detected by western blotting. The difference in LASS2 protein expression among the four cell lines was statistically significant.