Department of Neurosurgery, Wuxi Second Hospital Affiliated to Nanjing Medical University, Wuxi   214002, Jiangsu Province, China

Xiaojie Lu☆, M.D., Ph.D., Chief physician, Department of Neurosurgery, Wuxi Second Hospital Affiliated to Nanjing Medical University, Wuxi 214002, Jiangsu Province, China Lu XJ, Chen KL, Ji WY, Wang Q, Li B, Li JA, Sun JY. Expression for peroxisome proliferator-activated receptor gamma in pituitary adenomas: 38 cases for semi-quantitative immunohistochemical analysis. Neural Regen Res 2008;3(7):756-9

Abstract

BACKGROUND: It has been reported that peroxisome proliferator-activated receptor ? (PPAR?) is highly expressed in lung cancer, colon cancer, and gastric cancer, as well as other tumors.

OBJECTIVE: To study expression of PPAR?in pituitary adenomas and analyze the role of PPAR?in hormonal typing of pituitary adenomas.

DESIGN, TIME AND SETTING: Semi-quantitative immunohistochemistry of pathological specimens. The experiment was conducted at the Department of Neurosurgery, Wuxi Second Hospital Affiliated to Nanjing Medical University between January 2002 and May 2005.

MATERIALS: Surgical resection samples of pituitary adenomas from 38 cases (18 male and 20 female) were analyzed. Eight cases were determined to be invasive pituitary adenomas and 30 cases were non-invasive pituitary adenomas. Hormonal classification of the types of pituitary adenomas revealed somatotrophic adenomas in six cases, corticotrophic adenoma in five cases, prolactinomas in 13 cases, multi-hormone secreting adenomas in six cases, and eight cases of adenoma without altered endocrine function. Five autopsy specimens were collected during the same period from patients of matching age that died from unrelated diseases and were included as normal anterior pituitary controls.

METHODS: Cell counts for positive immunohistochemical signals were recorded from histopathological sections. The percentage of positive cells was reported as a semi-quantitative analysis.

MAIN OUTCOME MEASURES: The rate of PPAR?positive cells in different types of adenoma was based on hormonal levels and invasiveness of pituitary tumor cells.

RESULTS: All tumor biopsies were determined to express PPAR?. The rate of PPAR?-positive cells ranged between 8%-65% in the pituitary adenomas. According to hormonal type, PPAR?expression did not vary between the groups. In addition, there was no significant difference in PPAR?expression between the non-invasive and invasive pituitary adenomas．

CONCLUSIONS: Human pituitary adenomas express PPAR?, and this expression is unrelated to hormonal type and invasiveness.

Key Words: Peroxisome proliferator-activated receptor?; pituitary adenomas; immunohistochemistry

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