Expression of bcl-2 protein in lymphocytes of patients with laryngeal carcinoma

The aim of this study was to evaluate the expression of bcl-2 protein in ly mphocytes of the peripheral blood of patients with laryngeal carcinoma. The protein product of the proto-oncogene bcl-2 is a physiological inhibitor o f apoptosis or programmed cell death. Since we believe that apoptosis is in volved in the regulation of an immune response to a cancer process, we trie d to show how this mechanism works in laryngeal carcinoma in comparison wit h normal peripheral blood lymphocytes of healthy controls. To explain the s ignificance of this molecule's expression, we used flow cytometry to examin e the expression of bcl-2 in T lymphocytes from the peripheral blood of 23 patients with laryngeal carcinoma and 20 healthy controls. Our study reveal ed that the expression of bcl-2 protein in T lymphocytes from the cancer pa tients was significantly higher than in the controls (P < 0.05). This diffe rence in the expression of bcl-2 protein was found in both CD4 and CD8 subp opulations and was significantly higher than in the control group. In patie nts with laryngeal carcinoma expression of bcl-2 protein in T lymphocytes w as higher in CD4 than in CD8 cells (P < 0.05). These results suggest that b cl-2 protein may interact in the regulation of apoptosis of lymphocytes, ta king part in anti-cancer defence.