Expression of caveolin-1 and its correlation with cisplatin sensitivity in oral squamous cell carcinoma.

PURPOSE

Cisplatin (CDDP) is widely used for chemotherapy of oral squamous cell carcinoma (OSCC). However, the mechanism of resistance to CDDP is unclear. Recently, caveolin-1 was identified as being associated with both metastasis and multidrug resistance. In the present study, we showed that caveolin-1 expression is significantly related to chemosensitivity in OSCC.

METHODS

We established a CDDP-resistant cell line, H-1R, from the parental OSCC cell line, H-1. Caveolin-1 expression was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) in both cell lines. We analyzed expression of caveolin-1 in 30 OSCC biopsy specimens and investigated the relationship between expression of caveolin-1 and patients' clinicopathological parameters and chemotherapeutic responses.

RESULTS

The 3-(3,4-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that H-1R has a ten-times greater resistance to CDDP than H-1 has. The level of caveolin-1 expression in H-1R was significantly decreased in comparison with that in H-1 by real-time RT-PCR analysis. Positive caveolin-1 immunostaining correlated positively with a complete response (16/20, 80.0%). However, negative immunostaining was found in 6/7 (85.7%) cases with no response. Positive immunohistochemical staining of caveolin-1 correlated positively with chemosensitivity to CDDP-based combination chemotherapy (P=0.02).

CONCLUSIONS

These results suggest that overexpression of the caveolin-1 gene may provide novel diagnostic markers associated with CDDP sensitivity in OSCC.