Sulindac sulfone induces a decrease of beta-catenin in HNSCC.

BACKGROUND

The most common neoplasm arising in the upper gastrointestinal tract is head and neck squamous cell carcinoma (HNSCC). This is an aggressive epithelial malignancy. Many growth factors and cytokines have been discovered that are responsible for the growth and formation of tumours. Among these factors, beta-catenin is considered to be the most important for reducing cell-cell adhesions in malignant tissue. The degradation of beta-catenin triggers apoptosis by different routes. Sulindac sulfone has been shown to induce apoptosis in several different tumours. In the present study, we surveyed the concentration of beta-catenin in an HNSCC line after incubation with different concentrations of sulindac sulfone.

MATERIALS AND METHODS

Immunohistochemical and Western blot analyses were performed after treatment of the UMSCC 11A cell line with different concentrations of sulindac sulfone (100, 200, 400, 600 and 800 microMol) for 48 hours.

RESULTS

At 100 microMol of sulindac sulfone, a decrease in beta-catenin concentration of 5% was observed; increasing concentrations of sulindac sulfone resulted in >70% reduction in secreted beta-catenin. Thus in conclusion, incubation with sulindac sulfone seemed to stop proliferation. With respect to the controls, there was no greater reduction in total protein.

CONCLUSION

In this study, sulindac sulfone reduced levels of secreted beta-catenin in the HNSCC cell line UM-SCC 11A after 48 hours of incubation. It is presumed that reduction of cell-cell adhesion, which is predominately affected by beta-catenin, is an essential step in the progression from localized malignancy to stromal and vascular invasion and ultimately metastatic disease. The reduction in the level of mural expression of beta-catenin has been associated with loss of differentiation in laryngeal carcinomas. Thus, prevention of intracellular beta-catenin accumulation is regarded as an attractive target for chemopreventive agents.