High levels of miRNA-103/107 are associated with poor outcome in 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’ survival 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 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 cells 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 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 cannot be considered as prognostic factors. SK-OV-3 cancer cell lines was characterised 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.