[The expression and significance of bcl-2 and bax in each phase of the cell cycle in laryngeal carcinoma].

Objective: To detect the expression of bcl-2 and bax in each phase of cell cycle in laryngeal carcinoma, and explore the relationship between the expression of bcl-2 and bax in each phase of the cell cycle and the occurrence, development and prognosis in the carcinoma of larynx.

Methods: The immunohistochemical method, TUNEL technique and flowcytometry (FCM) parameter analyses were combined to detect the apoptosis and the expression of bcl-2 and bax in each phase of the cell cycle in 15 polyps of vocal cord and 387 laryngeal carcinomas.

Results: Total bcl-2 expression and bcl-2 expression in G0G1 stage in laryngeal carcinoma was significantly higher than that in polyp of vocal cord. In contrast, the total bax expression and the bax expression in each phase of cell cycle in laryngeal carcinoma were all lower than that in polyp of vocal cord. The total apoptosis index in laryngeal carcinoma was obviously lower than that in polyp of vocal cord, and this phenomenon was mainly caused by the decrease of the apoptosis in G0G1 phase. The bcl-2, bax expression and the apoptosis wasn't notably related to clinical stage, clinical type and T grade. In poor-differentiated squamous carcinoma, the bcl-2 expression in S and G2M phase was obviously higher than that in well-differentiated and the moderate-differentiated squamous carcinoma. The total apoptosis index, the apoptosis in S phase and the apoptosis in G2M phase were obviously enhanced both in the group of recurrence and in the patients who died in 5 years after the operation, in the same samples, the significant increasing of bcl-2 expression in S and G2M phase was detected.

Conclusions: The significant decreasing of the apoptosis in G0G1 phase caused by high expression of bcl-2 was an important affair in the initial stage of laryngeal carcinoma. Accompanying the significant increasing of the total apoptosis index, the apoptosis in S phase and the apoptosis in G2M phase could be regard as an indicator that the cancer of larynx was malignant with poor prognosis and need adjuvant therapy. The decreasing of bax expression may play a role in the occurrence of laryngeal carcinoma.