Potential role of LMP2 as an anti-oncogenic factor in human uterine leiomyosarcoma: morphological significance of calponin h1.

Uterine leiomyosarcoma (LMS) is a highly metastatic smooth muscle neoplasm for which calponin h1 is suspected to have a biological role as a tumor-suppressor. We earlier reported that LMP2-null mice spontaneously develop uterine LMS through malignant transformation of the myometrium, thus implicating this protein as an anti-tumorigenic candidate as well. In the present study, we show that LMP2 may negatively regulate LMS independently of its role in the proteasome. Moreover, several lines of evidence indicate that although calponin h1 does not directly influence tumorigenesis, it clearly affects LMP2-induced cellular morphological changes. Modulation of LMP2 may lead to new therapeutic approaches in human uterine LMS.