Role of TG2 and TGF-β in the pathogenesis of human breast cancer.

The present study analyzed the role of transforming growth factor-β (TGF-β) and tissue transglutaminase (TG2) in breast cancer, as well as their protein levels in MCF-7 cells treated with cisplatin. In addition, the present study investigated the effects of TG2 and TGF-β in MCF-7 cells following TGF-β and TG2 inhibition or TGF-β induction. The protein levels of TG2 and TGF-β in breast cancer tissues and in MCF-7 cells treated with cisplatin, TG2 and TGF-β inhibitors or 10 ng/ml TGF-β were analyzed by immunohistochemical staining, immunofluorescence and western blotting. The results revealed that the expression levels of TG2 and TGF-β in breast cancer tissues were significantly higher compared with those in paracancerous tissues. The fluorescence intensity of TG2 and TGF-β in MCF-7 cells treated with cisplatin was lower compared with that in untreated MCF-7 cells. Using bioinformatics analysis, the present study predicted that TGF-β may be associated with TG2. In addition, the expression levels of TGF-β and TG2 in MCF-7 cells treated with inhibitors of TGF-β and TG2 were lower compared with those in untreated MCF-7 cells. By contrast, the expression levels of TGF-β and TG2 in MCF-7 cells treated with TGF-β were higher compared with those in untreated MCF-7 cells. Therefore, the present study demonstrated that TGF-β and TG2 may serve an important role in breast cancer tissues and in MCF-7 cells. In addition, it was revealed that TG2 and TGF-β may have a synergistic role in MCF-7 cells.