Altered mRNA expression of sialyltransferase in squamous cell carcinomas of the cervix

Objective. Increased sialylation has been reported in various kinds of cancers, but to date, sialylation of cervical carcinoma has never been evaluated. This study of the changes in messenger ribonucleic acid (mRNA) expression of the four sialyltransferases (ST3Gal I, ST3Gal III, ST3Gal IV, and ST6Gal I) in a normal cervix and that with FIGO stage IB I squamous cell carcinoma was undertaken to assess the extent of sialylation associated with establishment of the carcinoma. Methods. Alterations in ST mRNA expression in FIGO IB1 cervical cancer (n=30) and normal cervixes (n=30) were examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Results. ST6Gal I expression was enhanced in squamous cell carcinoma of the cervix (P=0.026, Mann-Whitney U test), but mRNA expression from the other three STs (ST3Gal I, ST3Gal III, and ST3Gal IV) was significantly down-expressed in squamous cell carcinoma of the cervix compared to the normal cervix (P=0.003, P<0.001, and P=0.001, respectively). High ST6Gal I expression was associated with more invasive properties of cervical cancer, such as deep stromal invasion, lymph or vascular space involvement, and poor differentiation (P=0.010, P<0.001, P<0.001, respectively). Conclusions. A combination of enhanced ST6Gal I mRNA expression and decreased mRNA expression from ST3Gal I, ST3Gal III, and ST3Gal IV might be important in cervical cancer. Future studies will investigate whether RT-PCR detection of the expression of these enzymes can be helpful for prognostic purposes. (C) 2001 Academic Press.