MiRNA-103/107 in primary high-grade serous ovarian cancer and its clinical significance

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.