High expression of RRM2 promotes the pathogenesis of malignant ovarian endometriosis.

Abstract

Objective: Our objective was to investigate the upregulated expression of ribonucleotide reductase M2 (RRM2) in the ectopic endometrium (EC) of ovarian endometriosis (OE) patients that may indicate malignant transformation. RRM2 may be used as a marker of OE, which contribute to the research of the mechanism of the malignant transformation of OE.Methods: The gene expression profiles of ovarian cancer and OE were downloaded from Gene Expression Omnibus (GEO), and a common hub gene, RRM2, was identified. The expression of RRM2 was low in OE and high in ovarian cancer. A total of 44 patients with endometriosis-associated ovarian cancers (EAOC) and 44 with OE were enrolled in this study. Immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect the expression of RRM2, while the relationship between RRM2 and Ki-67 was analyzed by IHC co-localization. Results: There was no significant difference in the expression of RRM2 in the eutopic endometrium (EU), EC, and cancer tissues of EAOC patients. Compared with OE patients, the mRNA and protein expression levels of RRM2 were higher in the EC of EAOC patients (p＜0.01). Moreover, the high expression of RRM2 was consistent with the expression of Ki-67 in EC of EAOC patients.Conclusions: The upregulated expression of RRM2 in the EC of OE patients may indicate malignant transformation. RRM2 may be used as a marker of OE, which allows the investigation of the mechanism of the malignant transformation of OE.

High RRM2 expression has poor prognosis in specific types of breast cancer

“…The expression and role of RRM2 have been reported in a variety of cancers [ 10 , 19 ]. However, its role in breast cancer and its mechanism are still unclear.…”

“…Studies have shown that gene mutations and gene disorders are the main reasons leading to the occurrence and development of many cancers [ 4 ]. The differential expression of RRM2 is closely related to the occurrence, development, and prognosis of pancreatic cancer, gastric cancer, non-small cell lung cancer, liver cancer, malignant endometriosis, and other tumors [ 5 – 10 ]. Although targeted therapies, immunotherapy, chemotherapy, and radiotherapy are effective in the treatment of breast cancer, morbidity and mortality are still increasing.…”