A Novel Diagnostic Marker: Proteasome LMP2/1i-Differential Expression in Human Uterus Mesenchymal Tumor

Uterine leiomyosarcoma (LMS) develops more often in the muscle tissue layer of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of uterine LMS is not substantially correlated with hormonal conditions, and the risk factors are not yet known. Importantly, a diagnostic-biomarker, which distinguishes malignant LMS from benign tumor leiomyoma (LMA), is yet to be established. Accordingly, it is necessary to analyze risk factors associated with uterine LMS, to establish a treatment method. Proteasome LMP2/1i-deficient mice spontaneously develop uterine LMS, with a disease prevalence of ~40% by 14 months of age. We found LMP2/1i expression to be absent in human LMS, but present in human LMA. Therefore, defec-tive-LMP2/1i expression may be one of the risk factors for LMS. LMP2/1i is a potential diagnostic-biomarker under the combination of candidate molecules for uterine mesenchymal tumors, especially uterine LMS, and may be a tar-geted-molecule for a new therapeutic approach. (160 words)