E Fazeli - Department of Medical Genetics, School of Medicine, Shahid Beheshti Univarsity of Medical Sciences, Tehran, Iran
S Piltan - Department of Medical Genetics, School of Medicine, Shahid Beheshti Univarsity of Medical Sciences, Tehran, Iran
H Sadeghi - Department of Medical Genetics, School of Medicine, Shahid Beheshti Univarsity of Medical Sciences, Tehran, Iran
M Gholami - Department of Biochemistry and Genetics, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran

Background: Uterine Leiomyomas (ULMs) are monoclonal, benign tumors that arise from the smooth muscle cells of the uterus. Regardless of their benign nature, ULMs may cause significant reproductive and gynecological complications during the reproductive years. Despite increasing researches, the molecular mechanisms underlying ULMs tumorigenesis and development are not fully understood; however Recent studies suggest that hypovitaminosis D plays an important role in uterine leiomyomas pathology. CYP24A1 encodes a mitochondrial enzyme that catalyzes the degradation of 1,25(OH)2D3, the active form of vitamin D, controlling the amount of active vitamin D in serum and many human tissues. Overexpression of CYP24A1 is reported in several human tumors and it is associated with cancer development, progression, and poorer prognosis. Circular RNAs (circRNAs) are a novel class of non-coding RNAs that their role in tumor biogenesis and progression has been proved in a number of human tumors; however, up to now, the relation between circRNAs and uterine leiomyomas remains unclear. Hsa_circ_ 0060927 is a circRNA and is derived from CYP24A1 gene, containing its exons 3-11.Objective: In the present study, we have evaluated the expression levels of hsa_circ_0060927 and CYP24A1 in uterine leiomyoma and adjacent tissues considering the MED12 mutation profile.Materials and Methods: The expression levels of hsa_circ_0060927 and CYP24A1 in 50 leiomyoma tissues and adjacent normal tissues were evaluated using quantitative real-time PCR (qRT-PCRs) considering MED12 mutation profile.Results: The results indicated the ectopic expression of hsa_circ_0060927 and CYP24A1 in 33.33% and 18.2% of uterine leiomyoma tissue samples, respectively; however, the expression of both transcripts were independent of the MED12 mutation profile in the leiomyoma samples.Conclusion: Present results provide primary evidence for the role of circRNAs in the development of leiomyoma and also for the potential role of 1,25(OH)2D3 in maintaining the proper function of normal myometrium cells. Taken together, the results suggest that the dysregulation of vitamin D signaling and metabolic pathways may be involved in uterine leiomyomas tumorigenesis.

Leiomyoma, Circular RNA hsa_circ_0060927, CYP24A1, MED12