Significance of ceramide and DNA ploidy in laryngeal carcinogenesis.

OBJECTIVE

To investigate the expression of ceramide produced by sphingomyelin and DNA ploidy in normal laryngeal mucosa, laryngeal precancerous lesions and laryngeal carcinoma.

METHODS

Eighty consecutive patients with leukoplakia larynx were identified from the archived pathology files of the Eye, Ear, Nose and Throat Hospital of Fudan University from 1990 to 2001. Among them, 23 patients developed laryngeal carcinoma. Flow cytometry and immunohistochemistry were performed to test DNA content and ceramide expression on normal tissue, precancerous lesions and laryngeal carcinoma.

RESULTS

Among 80 patients with laryngeal carcinoma, 23 cases were all aneuploids, and 57 diploids. Expression of ceramide decreased gradually from normal tissue via precancerous lesions to laryngeal carcinoma. Cell staining per high-power field was 400 +/- 30, 180 +/- 20, and 10 +/- 10, respectively (p < 0.05, t test). The expression of ceramide in the DNA diploid cell was higher than that in the aneuploid cell (p < 0.05, t test).

CONCLUSIONS

Ceramide, the second messenger in apoptosis, plays a significant role in the progression from precancerous lesion to carcinoma of the larynx. Reduction in ceramide may be the key factor in laryngeal carcinogenesis.