Expression of cyclins and cyclin-dependent kinases in smooth muscle tumorsof the uterus

To investigate the cell cycle regulatory mechanisms involved in the growth of smooth muscle tumors, we studied the expression of Ki-67, cyclins E and A, and their catalytic partners, the cyclin-dependent kinases cdk2 and cdc2 by using tissue specimens from benign and malignant smooth muscle tumors. These included 20 cases of usual leiomyoma (UL), 18 of cellular leiomyoma ( CL), 8 of bizarre leiomyoma (BL), 8 of uncertain malignant potential tumors (UMP) and 20 of leiomyosarcoma (LMS). The proliferation rare detected by K i-67 was low in normal myometrium and leiomyomas (UL, CL and BL), but it wa s markedly increased in LMS, The expression of the cyclins (E and A) and cd ks (cdk2 and cdc2) was also low in normal myometrium and leiomyomas, Howeve r, the expression; of these factors was markedly increased in LMS, In addit ion, a survival analysis using Log-rank test, revealed that LMSs with posit ive staining for cyclin A and with diffusely staining for cyclin E were ass ociated with significantly shorter survival, Our results suggest that expre ssion of cyclins and cdks may be involved in the growth control of uterine smooth muscle tumors. Int. J. Cancer (Pred, Oncol) 84:244-250, 1999, (C) 19 99 Wiley-Liss, Inc.