SF-1 Immunohistochemical Expression in Tumors
Myra Wilkerson, Fan Lin, Jianhiu Shi. Geisinger Medical Center, Danville, PA
Background: Steroidogenic factor 1 (SF-1) is a nuclear receptor that functions with other transcription factors to regulate several genes in the hypothalamic-pituitary-gonadal axis, and in gonadal and adrenal steroidogenesis. SF-1 is required for regulation of sex determination and differentiation, reproduction, and steroidogenesis. Nuclear expression of SF-1 has been described in adrenal cortical neoplasms and normal adrenal cortex, endometriosis, Leydig cells, Sertoli cells, and theca and granulosa cells. Published data on SF-1 expression in tumors is limited. In this study, we investigated the expression of SF-1 in a large series of tumors from various organs.
Design: Immunohistochemical evaluation of SF-1 expression (R&D systems, SF-1/NR5A1 antibody, clone N1665) was performed on 984 tumors from various organs using tissue microarray sections. The staining distribution was recorded as negative (<5% of tumor cells stained), 1+ (5-25%), 2+ (26-50%), 3+ (51-75%), or 4+ (>75%).
Results: The positive staining results (%) and the total number of cases for each entity (N) are summarized in Table 1. Twenty-three of 984 cases demonstrated positive nuclear staining for SF-1 protein and these cases consisted of adrenal cortical adenomas and testicular Leydig cell tumors. In addition, benign interstitial Leydig cells and Sertoli cells in seminiferous tubules evaluated for ITGCN all demonstrated positive staining for SF-1.
|Tumor||N||# Positive||% Positive|
|Adrenal cortical adenoma||24||20||83.3|
|Testicular Leydig cell tumor||3||3||100|
|Testicular classic seminoma||21|
|Testicular embryonal CA||18|
|Testicular yolk sac tumor||6|
|Urothelial CA primary to bladder||45|
|Pulmonary neuroendocrine CA||26|
|Pulmonary squamous cell CA||40|
|Pancreatic endocrine CA||16|
|Clear renal cell CA||68|
|Papillary renal cell CA||17|
|Chromophobe renal cell CA||23|
|Infiltrating duct CA of breast||94|
|Infiltrating lobular CA of breast||26|
|Papillary CA of thyroid||42|
|Follicular CA of thyroid||30|
|Follicular adenoma of thyroid||51|
|Ovarian serous ADC||43|