[Protein expressions of Fas and FasL in B-cell lymphoma and their significances].

ABSTRACT

BACKGROUND & OBJECTIVE: Fas and FasL have been proved to be the inductional genes of cell apoptosis. Genesis of many tumors relates with functional disorder and abnormal expressions of Fas and FasL. This study was designed to detect protein expressions of Fas and FasL in B-cell non-Hodgkin's lymphoma (B-NHL) and benign lymphoid tissue, and to provide new markers for diagnosis of lymphoma. METHODS: Immunohistochemistry was used to detect protein expressions of Fas and FasL in 92 specimens of B-NHL, and 20 specimens of benign lymphoid tissue. RESULTS: Fas mostly expressed on membrane. FasL mostly expressed in cytoplasm, and partially expressed in nuclei. Positive rate of Fas in B-NHL was 66.3% (61/92), and that of FasL in B-NHL was 67.4% (62/92). Positive rates of both Fas and FasL in benign lymphoid tissue were 60.0% (12/20). There was no significant difference in expressions of Fas and FasL between B-NHL group and benign group (P>0.05), but positive locations of Fas and FasL in these 2 groups are different. Positive rates of Fas and FasL were higher in diffuse large B-cell lymphoma (DLBL) than in follicular lymphoma (FL), and small cell lymphoma (SLL) (87.2% vs. 64.5%, and 31.8%, P<0.05u 89.7% vs. 67.7%, and 27.3%, P<0.05). Positive rates of Fas and FasL in FL were higher than those in SLL. No correlation was found between Fas/FasL expression and patients' gender, age, and tumor location. CONCLUSIONS: The expressions of Fas and FasL are not useful for distinguishing benign lymphoid tissue from lymphoma tissue, while their locational characteristics are valuable for differential diagnosis. The expressions of Fas and FasL are considered valuable in evaluating the malignant grade of B-NHL.