Comparison of the miR-23b and miR-203 Expressions in Endometrial Cancer

Abstract

Brain Busan 21 사업단 MicroRNAs (miRNAs/miRs) are a group of small noncoding RNAs that modulate gene expression. Many studies, demonstrating altered expressions of specific miRNAs in diverse types of human neoplasia, suggested that they may play a key role in tumorigenesis. Recently, miRNA genes were found to be abnormally expressed in several types of cancer, including endometrial cancer. However, miR-23b and miR-203 expression in endometrial cancer has yet to be studied in Korea. As such, the purpose of this study was to analyze miR-23b and miR-203 expressions in endometrial cancer and to evaluate the relationship between miR-23b and miR-203 expressions. A retrospective study was carried out on the formalin-fixed, paraffin-embedded tissues of 42 endometrial cancer tissues using quantitative real-time PCR. In endometrial cancer tissues, miR-23b expression levels (2.70±4.45) were higher than miR-203 expression levels (−2.34±4.08). Endometrial cancer tissues showed an overexpression of miR-23b in 30 (71.4%) of the 42 endometrial cancer cases, whereas miR-203 was underexpressed in 29 (69.0%) of the 42 cases. There was a significant association between miR-23b and miR-203 expressions in endometrial cancer tissues (p=0.0005). These findings suggest that miR-23b and miR-203 expressions may be involved in endometrial carcinogenesis. More studies are needed to further define the relationship between miR-23b and miR-203 expressions and tissue-specific protein expression.

Elevated Circulatory Proline to Glutamine Ratio (PQR) in Endometriosis and Its Potential as a Diagnostic Biomarker

“…The results are well in line with previous clinical/preclinical studies suggesting mitochondrial dysfunction and decreased energy production in uterine endometriosis tissue, 48 as proline catabolism in mitochondria serves as an important source of energy production and previous transcriptomics studies have demonstrated that there is reduced expression of proline oxidase (POX, a mitochondrial inner-membrane flavoenzyme involved in the catabolic degradation of the proline) due to overexpression of microRNA (known as MiR-23b). 31 , 49 Epigenetics studies on clinical samples have demonstrated that miRNA-23b exhibits regulatory roles, especially in the development of cancer, 50 , 51 and its overexpression is negatively correlated with the expression of tumor suppressor gene TUSC7 in endometrial carcinoma. 52 Studies have shown that miRNA-23b directly binds the POX mRNA 3′-untranslated region; thus, the overexpression of miRNA-23b is directly correlated with downregulation of mitochondrial proline oxidase (POX), as schematically depicted in ( Figure 5 A).…”

“… 40 So far, there is no single biomarker or panel of biomarkers in the blood that has been validated as a clinical test for the diagnosis of endometriosis or definition of its stages. 40 In this targeted metabolomics study, an attempt has been made to validate the previously reported hallmark of endometriosis; that is, the microRNA named miR-23b is overexpressed during EM tumor progression, 49 which markedly suppresses the expression of mitochondrial POX enzyme (a novel tumor suppressor), rendering decreased utilization of proline in the generation of reactive oxygen species (ROS, critical for regulation of cell growth and apoptosis). 53 The availability of proline, on the other hand, induces collagen synthesis—a process essential for tumor growth and progression.…”