EXPRESSION OF PROTHYMOSIN-ALPHA AND C-MYC MESSENGER-RNA IN HUMAN GASTRIC-CANCER

Prothymosin-alpha (PT-alpha) is a nuclear protein involved in cell pro liferation. c-myc is implicated in the carcinogenesis of many human ca ncers. PT-alpha gene transcription is reported to be regulated by the c-myc gene in vitro. However, little has been reported on the PT-alpha and c-myc mRNA expressions in gastric cancer. We semi-quantitatively determined the PT-alpha and c-myc mRNA expressions in 60 pairs of gast ric cancer tissue (T) and corresponding normal tissue (N) using the re verse transcriptase-polymerase chain reaction method. The average of T /N ratio was 1.20 for PT-alpha and 1.30 for c-myc. Cases demonstrating a T/N ratio of more than 1.0 were seen in 33 (55%) and 30 (50%) cases for PT-alpha and c-myc, respectively. No significant correlation was observed between either of these two mRNA expressions and any of the e xamined clinicopathologic factors for gastric cancer. However, a signi ficant correlation was seen between the expressions of both genes (p<0 .0001). The findings support the hypothesis that, regarding human gast ric cancer, the transcription of PT-alpha is considered to be under th e control of c-myc gene, however, the value of these gene expressions do not reflect biological behavior.