title: Local expression of epidermal growth factor-like growth factors in human testis and its role in spermatogenesis.
abstract: Microdissection testicular sperm extraction (micro-TESE) has revealed that  spermatogenesis in nonobstructive azoospermia (NOA) patients is heterogeneous,  even in the same testis, but there is no information regarding growth factors  to support spermatogenesis. We investigated the involvement of epidermal  growth factor (EGF)-like growth factors, which play important roles in  cell proliferation and differentiation in NOA patients who underwent  micro-TESE. Testicular samples were obtained from 5 fertile men (15 samples),  5 prostate cancer patients receiving maximum androgen blockade (10 samples),  and 13 NOA patients who underwent micro-TESE (50 samples). The expression of  the mRNA for EGF, heparin binding (HB)-EGF, amphiregulin, epiregulin,  betacellulin, and transforming growth factor (TGF)-α were analyzed  by real-time polymerase chain reaction analysis and adjusted using the  expression of glyceraldehyde-3-phosphate dehydrogenase. Heterogeneous  expression of these EGF-like growth factors were observed even in the same  testis. The expression of HB-EGF, amphiregulin and TGF-α in NOA and  prostate cancer patients was significantly lower than observed in fertile  controls. In NOA patients, expression in the testicular sample comprising  mature sperm was significantly higher than those without mature sperm,  indicating that HB-EGF, amphiregulin, and TGF-α are considered to  participate in creating a suitable niche for spermatogenesis. Considering the  findings that ablation of gonadotropin inhibited and human chorionic  gonadotropin stimulation increased these EGF-like growth factors, the  expressions are presumably under gonadotropin regulation.
authors.affiliation: Department of Urology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. shirak@yamaguchi-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Shiraishi
authors.forename: Hideyasu
authors.initials: H
authors.lastname: Matsuyama
mesh_terms: D000328:Adult; D001483:Base Sequence; D017931:DNA Primers; D004815:Epidermal Growth Factor / Q000378:metabolism*; D006801:Humans; D007621:Karyotyping; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism* / Q000502:physiology
chemical_list: D017931:DNA Primers; D004815:Epidermal Growth Factor