Conclusions
Our data suggest that PINCH-2 mRNA is overexpressed in malignant mesothelioma compared with carcinomas involving serosal cavities, and that low levels of this gene argue against the diagnosis of mesothelioma. The frequent PINCH-2 protein expression in all three studied cancers suggests a role for this molecule in cancer cell biology in effusions and merits further research.
Methods
Effusions (n = 91; 71 ovarian and 10 breast carcinomas, 10 malignant mesotheliomas) were assayed for PINCH-2 mRNA expression using quantitative PCR. PINCH-2 protein expression was analysed in 37 effusions using flow cytometry.
Objective
The PINCH-2 gene was previously shown to be overexpressed in malignant mesothelioma compared with ovarian/peritoneal serous carcinoma in Affymetrix array analysis. The objective of the present study was to validate this finding at the mRNA and protein level.
Results
Quantitative PCR analysis showed significantly higher PINCH-2 mRNA levels in mesotheliomas compared with carcinomas (P = 0.004). Values of <10 copies were found exclusively in carcinoma effusions (25.4% of ovarian and 50% of breast carcinomas). However, PINCH-2 protein expression by flow cytometry did not differ significantly between the three cancer types. No association was observed between PINCH-2 levels and patient survival or expression of previously-studied molecules related to adhesion, metastasis and apoptosis inhibition in ovarian carcinoma. Conclusions: Our data suggest that PINCH-2 mRNA is overexpressed in malignant mesothelioma compared with carcinomas involving serosal cavities, and that low levels of this gene argue against the diagnosis of mesothelioma. The frequent PINCH-2 protein expression in all three studied cancers suggests a role for this molecule in cancer cell biology in effusions and merits further research.