Steroidogenic Acute Regulatory Protein is a Useful Marker for Leydig Cells and Sex-Cord Stromal Tumors

Abstract

Steroidogenic acute regulatory (StAR) protein is a rate-limiting protein, which is essential for transporting cholesterol into the mitochondria for steroidogenesis. StAR protein could be a marker for steroidogenic tissues. In this study, we investigated StAR protein levels in sex-cord stromal tumors (SCSTs) including 31 adult granulosa cell tumors, 3 juvenile granulosa cell tumors, 10 fibrothecomas, 2 luteinized thecomas, 4 Sertoli-Leydig cell tumors (SLCTs), 4 sclerosing stromal tumor and 3 Leydig cell tumors (LCTs), and 219 non-SCSTs. SCSTs were used for immunohistochemical staining of StAR protein, α-inhibin, calretinin, and CD99. All the 3 LCTs (100%) strongly stained for StAR protein; 30 of the 31 adult granulosa cell tumors (96%) showed focal staining of StAR protein; all the 10 fibrothecomas and 4 sclerosing stromal tumors (100%) were negative for StAR protein staining; StAR protein stained in Leydig cells but not in Sertoli cells in the 4 SLCTs. All the non-SCSTs were negative for StAR protein except for tumor cells in 4 adrenocortical adenomas and 2 adrenocortical carcinomas. Results of the study indicate that StAR protein is a useful marker for differential diagnosis of SCSTs. It is sensitive and specific for Leydig cells in tumors containing this component (LCT, SLCT), and can express focally in granulosa cell tumors. It is negative for Sertoli cells and nonluteinized theca cells.

Human spermatogonial stem cells display limited proliferation in vitro under mouse spermatogonial stem cell culture conditions

“…Because the expression of STAR is necessary for the earliest stages of steroidogenesis in Leydig cells (34), the down-regulation of later steroidogenic actors such as HSD3B1 (35) and the functional marker of Leydig cell secretion INLS3 (36) may be indicative of an early blockade of Leydig cell functionality in vitro. Testosterone quantifications of media employed for testicular cell cultures indicated insignificant changes in the levels of testosterone compared with fresh medium controls, supporting this hypothesis (Supplemental Fig.…”

Alterations of gene profiles in Leydig-cell-regenerating adult rat testis after ethane dimethane sulfonate-treatment

“…These 14 genes include vascular cell adhesion molecule 1, 22 vitronectin ( Vtn ), 23 insulin-like 3, 24 platelet derived growth factor receptor α, 25 carboxylesterase, 26 7-dehydrocholesterol reductase, 27 epoxide hydrolase 2, 22 Cyp1b1 , 28 17β-HSD10 ( Hsd17b10 ), 29 Cyp2a1 , 8 30 Cyp11a1 ( Figure 7 ) and Cyp17a1 , 31 32 Hsd3b1 , 32 and StAR . 33 Another five genes have also been confirmed to be abundantly present in ALCs, including gap junction protein, alpha 1 ( Gja1 ), 34 mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase, 35 peripheral-type benzodiazepine receptor, 36 Hsd11b1 , 18 and Fabp3 ( Figure 7 ). Using this approach, we identified several pathways that were predominantly present in rat ALCs.…”

Estradiol promotes cell survival and induces Greb1 expression in granulosa cell tumors of the ovary through an ERα‐dependent mechanism

“…Indeed, AT29 cells express inhibin α (Inha), βA (Inhba), and βB (Inhbb) subunit genes (supplementary material, Figure S4). In addition, they also displayed expression of STAR and AMH but not that of CYP19A1 [12,29,30] (supplementary material, Figure S4). FSHR transcripts were not detected, as in about 10% of human GCTs [12].…”