Inhibin/activin subunits and activin receptor are co-expressed in Leydig tumor cells.
The expression of genes encoding inhibin/activin subunits and activin receptor was examined in four cultured Leydig tumor cells (MA-10, I-10, R2C, and LC-540). Inhibin alpha-subunit gene was highly expressed in Leydig tumor cell lines except LC-540. Both inhibin beta-A- and beta-B-subunit mRNAs were present in low levels. The 6.5-kb beta-A-subunit mRNA was detected in MA-10, R2C and LC-540 cells, and not in I-10 cells. The expression of the two species of beta-B-subunit mRNA is cell specific. In MA-10 and I-10 cells, 4.4-kb beta-B-subunit mRNA was the predominant species, while in R2C and LC-540 cells both 4.4-kb and 3.3-kb mRNA were present in equal quantities. By contrast, two species (6 and 3 kb) of activin receptor ActRII mRNA were identified in equal intensity in all four Leydig tumor cell lines. Addition of cAMP derivative to MA-10 cells at 0.1 mM for 17 h or 1 mM for 5 h produced a two-fold increase in inhibin alpha-subunit mRNA levels, and small or no significant change in inhibin beta-B-subunit and ActRII mRNAs. However, a 70-80% reduction in inhibin beta-A-subunit mRNA was observed by 1 mM cAMP for 5 h. We concluded that: (1) the inhibin/activin subunit genes and activin receptor gene are co-expressed in Leydig tumor cell lines, and (2) the three inhibin/activin subunit genes are expressed differently, while the activin receptor gene is expressed identically in the four cell lines.
The Population Council, New York, New York 10021.
C L
CL
Chen
O P
OP
Pignataro
Z M
ZM
Feng
D029404:Activin Receptors; D000818:Animals; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007265:Inhibins / Q000096:biosynthesis* / Q000235:genetics; D007984:Leydig Cell Tumor / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D051381:Rats; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics; D013736:Testicular Neoplasms / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011956:Receptors, Cell Surface; D007265:Inhibins; D000242:Cyclic AMP; D029404:Activin Receptors