Inflammation-Related Tumor Progression in Murine Fibrosarcoma Exhibited Over-expression of Sex-determining Region Y-box 2 (Sox2) Compared to Parental Regressor Cells.

Tumor progression is one of the most serious issues to overcome cancer disease. As a model of inflammation-induced tumor progression, we used the regressive murine fibrosarcoma cell clone QR-32 and the progressive malignant clone QRsP-11, that was derived from QR-32. Heat shock protein beta-1 (Hspb1) is a molecular chaperone. Hspb1 plays roles in not only cell protection but also chemo-resistance, tumorigenicity and protection from apoptosis. In a recent study, we showed that Hspb1 was up-regulated in QRsP-11 compared to QR-32. We compared the expression levels of Hspb1, Hsf1 and Sox2 in QR-32 and QRsP-11 cells by means of western blotting. Hsf1, a transcription factor for Hspb1 was not increased in QRsP-11. Sex determining region Y-box 2 (Sox2) is a transcription factor, reported to interact with Hspb1. Sox2 was up-regulated in QRsP-11 compared to QR-32. These results suggest that Sox2-Hspb1 signaling is a possible pathway responsible to tumor progression of QRsP-11.