High levels of miRNA-103/107 are associated with poor outcomes in the case of breast cancer patients. MiRNA-103/107-DICER axis may be one of the key regulators of cancer aggressiveness. MiRNA-103/107 expression levels have never been related to patients’ clinicopathological data in epithelial ovarian cancer. We aimed to assess miRNA-103/107 expression levels in high grade serous ovarian cancer tissues. Expression levels of both miRNAs were related to the clinicopathological features and survival. We also evaluated expression levels of miRNA-103/107 and DICER in selected ovarian cancer cell lines (A2780, A2780cis, SK-OV-3, OVCAR3). We assessed the relative expression of miRNA-103/107 (quantitative reverse transcription-polymerase chain reaction) in fifty archival formalin-fixed paraffin-embedded tissue samples of primary high grade serous ovarian cancer. Then, miRNA-103/107 and DICER expression levels were evaluated in selected ovarian cancer cell lines. Additionally, DICER, N-/E-cadherin protein levels were assessed with the use of western blot. We identified miRNA-107 up-regulation in ovarian cancer in comparison to healthy tissues (p = 0.0005). In the case of miRNA-103, we did not observe statistically significant differences between cancerous and healthy tissues (p = 0.07). We did not find any correlations between miRNA-103/107 expression levels and clinicopathological features. Kaplan–Meier survival (disease-free and overall survival) analysis revealed that both miRNAs could not be considered as prognostic factors. SK-OV-3 cancer cell lines were characterized by high expression of miRNA-103/107, relatively low expression of DICER (western-blot), and relatively high N-cadherin levels in comparison to other ovarian cancer cell lines. Clinical and prognostic significance of miRNA-103/107 was not confirmed in our study.

IntroductionMicroRNAs (miRNAs) take part in tumorigenesis and show aberrant expression levels in cancerous tissues. We aimed to perform miRNA profiling of endometrioid endometrial cancer (EEC) metastatic loci derived from lymph nodes. Identification of aberrant miRNAs in positive lymph nodes could contribute to establishing new diagnostic markers and therapeutic targets.Material and methodsDuring the screening phase of the study, we performed profiling of 754 human miRNAs in endometrioid endometrial cancer tissues, microdissected metastatic loci from lymph nodes and healthy lymph nodes (Taqman Array). Selection of candidate miRNAs and subsequent validation using quantitative reverse transcription polymerase chain reaction (qRT‐PCR) in 50 tissue samples were performed.ResultsAfter the screening phase of the study, five miRNAs were selected (hsa‐miR‐18b, hsa‐miR‐148a‐5p, hsa‐miR‐204, hsa‐miR‐424, hsa‐miR‐129‐1‐3p). Validation revealed that miRNA‐204 and miRNA‐424 were highly downregulated in metastatic tissues compared with endometrial cancer samples (hsa‐miR‐204—P = .0008; hsa‐miR‐424—P = .0001). Receiver operating characteristic curves, which were constructed to compare endometrioid endometrial cancer and positive endometrioid endometrial cancer lymph nodes yielded the following area under the curves (AUCs): hsa‐miR‐204—.802 (96% confidence interval CI 0.676‐0.927), hsa‐miR‐424—.84 (95% CI 0.711‐0.969).ConclusionsCompared with primary endometrioid endometrial cancer tissue, metastatic loci derived from positive lymph nodes are characterized by profound downregulation of miRNA‐204 and miRNA‐424.