Enhanced expression of alpha 2,6-sialyltransferase ST6Gal I in cervical squamous cell carcinoma.
OBJECTIVE
Increased messenger ribonucleic acid (mRNA) expression of beta-galactoside alpha 2,6-sialyltransferase I (ST6Gal I) is important in squamous cell carcinoma (SCC) of the cervix. In many tissues, ST6Gal I is transcriptionally regulated through the use of promoters that originate in the mRNA species that diverge in the 5'-untranslated regions. To clarify the roles of ST6Gal I mRNA species in cervical SCC, we investigated their expression, including a "constitutive" promoter (placental or Y + Z form), "hepatic" promoter (H form), and a specific lymphoblastic promoter (X form), in normal and SCC tissues of the cervix using real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR).


METHODS
Expression of the ST6Gal I species was investigated in normal cervical tissue samples (n = 38) and FIGO IB1 cervical SCC samples (n = 38) by relatively quantitative real-time RT-PCR, using primers designed for amplification of a portion of the coding region common to all mRNA species or ones for amplification of the placental transcript, the hepatic transcript, or lymphoblastic transcript.


RESULTS
ST6Gal I mRNA expression was significantly increased in cancerous tissues compared to that in normal tissues (P = 0.004, Mann-Whitney U test; P < 0.001, paired t test). Expression of the Y + Z form did not appear to be affected by cancer transformation, since it was detected at comparable levels in normal and cancerous tissues (P = 0.986), but H form expression was significantly enhanced in cancerous tissues compared to that in normal tissues (P < 0.001, Mann-Whitney U test and paired t test). Surprisingly, the X form could be detected in some patients with and without cancer, but the detection rate was significantly higher in patients with cancer (86.8% vs 52.6%, respectively; P = 0.021, Fisher's exact test). Although the X transcript was detected at a low level compared to the H and Y + Z transcripts, its expression was also significantly enhanced in patients with cancers compared to those without cancers (P < 0.001, Mann-Whitney U test and paired t test).


CONCLUSIONS
An increased level of hepatic transcripts may be important in cancer transformation because the transcripts contribute to enhance ST6Gal I expression in cancerous tissues.
Wang
Peng Hui
PH
Department of Obstetrics and Gynecology, Taipei Veterans General Hospital and Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
Lee
Wen Ling
WL
Lee
Yan Ru
YR
Juang
Chi Mou
CM
Chen
Yi Jen
YJ
Chao
Hsiang Tai
HT
Tsai
Ying Chieh
YC
Yuan
Chiou Chung
CC
D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009367:Neoplasm Staging; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012799:Sialyltransferases / Q000096:biosynthesis* / Q000235:genetics; D014158:Transcription, Genetic; D002583:Uterine Cervical Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D012333:RNA, Messenger; D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase