Analysis of the retinoblastoma gene in human endometrial carcinoma

OBJECTIVE: To examine the Rb gene that controls the cell cycle in human endometrial carcinoma. METHODS: Six endometrial carcinoma cell lines (Ishikawa, Hec1-A, Hec1-B, KLE, RL95-2, and AN3 CA) and 48 human endometrial carcinoma tissues were studied by Southern blotting, Northern blotting, polymerase chain reaction (PCR), and DNA sequencing. RESULTS: Southern blotting analysis did not reveal any abnormalities at the DNA level in the endometrial carcinoma cell lines. Size and quantity of Rb transcripts also appeared normal in these cell lines, as evidenced by Northern blotting and reverse transcription-PCR. Sequence analysis of Rb cDNA revealed that the Ishikawa cell line had an abnormality. In human endometrial carcinoma, 20 of 48 cases (42%) were informative and only two cases of 20 (10%) showed loss of heterozygosity at the Rb locus. CONCLUSION: An Rb gene abnormality was found in some human endometrial carcinomas. Therefore, our results suggest that Rb gene abnormalities may be involved in some human endometrial carcinogenesis.