Increased Nuclear Localization of β - catenin by rhBMP - 2 in the Induced Oral Squamous Cell Carcinoma in the Syrian Hamster Cheek Pouch

Abstract

Background: Recombinant human bone morphogenetic protein 2 (rhBMP - 2) regulates several functions within human cells, including invasion, adhesion, differentiation, proliferation, and programmed death. The intercellular role of this protein in cancer progression has been extensively investigated in recent studies. Alterations in β - catenin could also promote cancer progression throughout the Wnt/β - catenin signaling pathway. The present study aimed to evaluate the effect of rhBMP - 2 on the expression and localization of β - catenin in the induced oral squamous cell carcinoma (OSCC) in the buccal pouches of golden Syrian hamsters. Methods: Buccal cavities of 57 hamsters were scrubbed by 5% 7,12 - dimethylbenz[a]anthracene (DMBA) three times per week for 3.5 months. In addition, the animals in the test group (n = 29) were injected with 0.25 µg of rhBMP-on days one, seven, and 49 of the study, and biopsies were extracted afterwards. The expression of β - catenin was immunohistochemically studied in the affected tissues. Results: Membranous β - catenin expression was observed in 71.1% of the cells in the animals in the test group and 64.8% of the control subjects. However, no significant difference was observed between the study groups (P > 0.05). Moreover, nuclear β - catenin expression was detected in 39.1% and 23.6% of the cells in the test and control groups, respectively with a significant difference in this regard (P < 0.05). Conclusions: According to the results, rhBMP - 2 increased the nuclear localization of β - catenin in the OSCC and activated the Wnt/β - catenin signaling pathway. However, evidence is scarce on the increased invasiveness due to the loss of β - catenin membranous expression.