Predictive and prognostic value of SALL4 and Tau protein in serous ovarian cancer patients treated with chemotherapy.

Background: Serous ovarian carcinoma (SOC) forms high percentage of epithelial ovarian cancer with frequent relapse and drug resistance. Spalt-like transcription factor SALL4 is a zinc finger transcriptional factor that regulates multiple downstream targeted genes included in normal development, essential in maintaining pluripotency and self-renewal of embryonic stem cells (escs). The role of SALL4 in serous ovarian carcinoma (SOC) is still controversial although it is involved in some tumor progression. Tau protein (50–64 kd), a product of gene located in chromosome 17 (17q21) shows the ability of combining to beta-tubulin. It may bind to the exterior as well as to the interior microtubules surface and its function has been extensively associated with neurodegenerative diseases. Aim of the work: To explore and assess the Predictive and prognostic role of SALL4 and Tau protein immunohistochemical expressions in serous ovarian carcinoma patients treated with paclitaxel/ carboplatin first-line chemotherapy. Methods: Immunohistochemical expressions of SALL4 and Tau protein were evaluated in sections from 50 paraffin blocks of serous ovarian carcinoma patients. The relationship between their level of expressions, prognosis and predictive value in serous ovarian carcinoma patients treated with paclitaxel/platinum first-line chemotherapy was analyzed. Results: The expression of SALL4 in serous ovarian carcinoma was signifi¬cantly positively correlated with grade, stage, lymph node metastasis (p<0.001), local recurrence of the tumor (p=0.002) and distant metastasis (p=0.005). The expression of Tau protein was signifi¬cantly positively correlated with grade, stage, lymph node, distant metastasis (p<0.001) and local recurrence of the tumor (p=0.002). High SALL4 expression was signifi¬cantly positively correlated with response to treatment, performance status worse 3-year overall survival (OS) and local recurrence free survival rate (P =0.018, 0.01, 0.008 and <0.001 respectively). High Tau protein expression were signifi¬cantly positively correlated with response to treatment, performance status, worse 3-year overall survival (OS) rate, local recurrence free survival rate (p<0.001) and resistance to the paclitaxel/platinum first-line chemotherapy (p= 0.021). Conclusion: SALL4 and Tau protein may be considered as poor prognostic and predictive markers in serous ovarian carcinoma.