Identification and partial characterization of differentially expressed mRNAs in normal human endometria and endometrial carcinomas by differential display RT-PCR

Differential display methodology was employed to examine and compare the mRNA species derived from normal endometrial tissue and endometrial carcinoma (grade 3, stage III) tissue biopsies. Two cDNA sequences, one expressed in the tumour group only (T19) and the other expressed only in the normal group (N22), were selected for verification of differential expression by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The expression of N22 was restricted to the normal group, suggesting a possible tumour suppressing function. Sequence analysis of this fragment revealed a high degree of similarity to a human cDNA sequence of unknown function. The expression of T19 mRNA was observed in both normal and neoplastic tissues, however the relative abundance was significantly higher in endometrial carcinomas. Expression of T19 mRNA was further examined in a larger clinical sample set and was significantly increased in the tumours (n = 16), with a three-fold increase when compared with the normal endometria, n = 5 (Kruskal-Wallis analysis of variance, P<0.05). Subsequent sequence analysis of T19 revealed a high degree of similarity to the 3' untranslated region of a rat growth factor responsive gene, SM-20. Further characterization of these mRNA transcripts may lead to the identification of novel genes involved in endometrial tumourogenesis.