AhR is a prognostic marker of survival in ovarian cancer patients

Aim:

Originally identified as a receptor of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), AhR has since been observed in multiple tumor types. The AhR receptor seems to have cancerogenic effects, however, its role in ovarian cancer has not been extensively investigated. We aimed to determine the level of AhR expression in ovarian cancer specimens and to define its correlation with clinical and pathological data as well as survival.

Materials and methods:

AhR protein expression was evaluated by Western blotting in four different ovarian cancer cell lines (OVCAR-3, ES-2, TOV-112D, and UWB1.289) as well as in the benign ovarian cell line (HS 832). Immunohistochemistry was used to analyze AhR staining in 156 samples of ovarian cancer patients. AhR staining was assessed in the nucleus and the cytoplasm using the semi-quantitative immunoreactive score (IRS) and grouped into high and low-level expression.

Results:

Our results show that high cytoplasmic expression of AhR leads to reduced overall survival (p = 0.021).

AhR protein expression was detected in all cell lines, the clear cell type displaying the highest protein levels.

Similarly, patients with clear cell ovarian cancer were observed to have the highest AhR expression compared with other subtypes.

Clear cell carcinoma patients with high nuclear AhR expression show a reduced survival outcome (p = 0.001).

Conclusion:

We found that cytoplasmic AhR expression is a negative prognostic marker for ovarian cancer. Our data suggest that AhR expression is increased in clear cell ovarian cancer patients, showing a reduced survival outcome in a group of patients.