Differential expression of IGF components and insulin receptor isoforms in human seminoma versus normal testicular tissue.

Insulin-like growth factors (IGF) have mitogenic and antiapoptotic functions, and may be involved in tumor growth. The purpose of the study was to investigate the role of IGF components in seminoma compared to normal testis. Normal testicular tissues from autopsy cases and seminoma from surgery cases were obtained for microarray and real-time reverse transcription polymerase chain reaction (RT-PCR) analysis of IGF-1, IGF-2, IGF receptor type 1 (IGF-R1), IGF-R2, insulin receptor isoforms A (IR-A) and B (IR-B), and IGF-binding proteins (IGFBP) 1-6.

Standardization strategy for quantitative PCR in human seminoma and normal testis.

Housekeeping genes are commonly used as endogenous references in quantitative RT-PCR. Ideally these genes are constitutionally expressed by all cell types and do not vary under experimental conditions. Tissues of 9 normal testes and 22 classical pure seminoma were obtained for RNA-extraction.

The mRNA expression of insulin receptor isoforms (IR-A and IR-B) and IGFR-2 in the bovine corpus luteum during the estrous cycle, pregnancy, and induced luteolysis.

Isoform A of the human insulin receptor and the IGF-receptor type 2 (IGFR-2) are both receptors for insulin- like growth factor II (IGF II), which plays a major role in luteal development and function in bovine species. The objective of this study was to determine if both insulin receptor isoforms and IGFR-2 were expressed in the bovine corpus luteum (CL) and if they were regulated during the estrous cycle, pregnancy, and induced luteolysis. CL were collected at the slaughterhouse.