Relationship between expression of P21ras and cellular DNA in pleomorphic adenoma of lacrimal gland

BACKGROUND: The pleomorphic adenoma is the most frequent tumor of the human lacrimal gland comprising about 50% of the epithelial tumors of this organ. Although being benign, local recurrences can occur when the first removal was incomplete and malignant transformation is also not in frequent. It is well known that many sorts of cellular oncogene products are involved in the initiation, promotion and progression of the human neoplasm. Our purpose was to know whether there is abnormal expression of P21ras in pleomorphic adenoma. METHODS: We have undertaken a study of the expression of P21ras in 5 normal tissues and 32 pleomorphic adenoma of lacrimal gland by immunohistochemical means using the monoclone antibody F-132-62 and the nuclear DNA content in the tumor was assayed by image analysis technique. RESULTS: Normal tissues of lacrimal gland were negative, 12 tumors were stained positively with the antibody. The DNA content of 14 cases of tumor was increased. Their DNA ploidy distribution pattern showed two or several peaks. Good correlation has been found between the expression of P21ras and DNA ploidy distribution pattern, the DNA ploidy distribution pattern of tumor which expressed p21ras showed mainly two or several peaks. P< 0.05. CONCLUSIONS: The result of our studies may suggest that there are increased expression of p21ras in pleomorphic adenoma and the expression of p21ras is related to the promotion and progression of pleomorphic adenoma of lacrimal gland.