Dominant expression of sex-hormone-binding-globulin exon-7 splicing variant over wild-type mRNA in human ovarian cancers.
The intracellular expression of sex-hormone-binding-globulin(SHBG) exon-7-splicing-variant mRNA in human ovarian cancers was demonstrated by reverse-transcription/polymerase-chain-reaction, Southern-blot and DNA-sequencing analyses. Analysis of the missing base pairs proved that they corresponded to the entire exon 7, which is considered to encode a portion of the steroid-binding site, suggesting that the steroid-binding affinity of this variant might be different from that of the SHBG wild type. SHBG wild-type and variant mRNA was detected in all normal ovaries and in benign and malignant ovarian tumors analyzed. There were no significant differences in mean SHBG wild-type and variant mRNA levels among the 3 types of tissue, but the ratio of SHBG exon-7-splicing-variant to wild-type mRNA level in ovarian cancers was significantly higher (p < 0.05) than that in normal ovaries, with over-expression in some benign tumors. SHBG mRNA levels and the ratio of SHBG variant to wild-type mRNA was not associated with histological classification or clinical stages of ovarian cancers. These results suggest that over-expression of SHBG-exon 7-splicing-variant mRNA to the wild type might indicate the potential for neoplastic transformation.
Department of Obstetrics and Gynecology, Gifu University School of Medicine, Japan.
R
R
Misao
Y
Y
Nakanishi
J
J
Fujimoto
S
S
Iwagaki
T
T
Tamaya
D015139:Blotting, Southern; D017931:DNA Primers; D005091:Exons / Q000235:genetics*; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012738:Sex Hormone-Binding Globulin / Q000235:genetics*; D014158:Transcription, Genetic
D017931:DNA Primers; D012333:RNA, Messenger; D012738:Sex Hormone-Binding Globulin