Differential Expression of NUDT9 at Different Phases of The Menstrual Cycle and in Different Components of Normal and Neoplastic Human Endometrium

Objective: The human endometrium manifests different and distinct morphologies and physiologies during the different phases of the menstrual cycle. We aimed to determine which candidate genes demonstrate differential expression patterns in the endometrium during different phases of the menstrual cycle. Materials and Methods: Using differential display reverse transcription polymerase chain reaction to compare day 5 and day 18 human glandular endometrium obtained by laser capture microdissection, we identified a specific gene, NUDT9 (nucleoside diphosphate-linked moiety X motif 9). NUDT9 is known to function as a highly specific adenosine diphosphate ribose pyrophosphatase and has been mapped to chromosome 4q22.1. It gives rise to two alternatively spliced messenger RNAs, NUDT9α and NUDT9β, encoding a member of the Nudix hydrolase family. In this study, we purified NUDT9 protein and produced an antibody, which we then used for immunohistochemical studies. Results: Using this anti-NUDT9 antibody, we successfully demonstrated that NUDT9 protein was differentially expressed in endometrial glandular cells at different phases of the menstrual cycle. NUDT9 was also found to be expressed more prominently in the epithelial glandular component than in the stromal component of human endometrial carcinomas. Conclusion: We suggest that NUDT9 may be involved in the regulation of the menstrual cycle and may be related to the proliferation of glandular cells in the human endometrium.