Figure 3.

OSF-2 expression does not directly contribute to cisplatin therapy resistance. (A) Selected cisplatin-resistant Pica_Cis and FaDu_Cis cells (grey) are highly resistant. Cells were treated with indicated cisplatin concentrations for 48 h and viability normalized to untreated controls. (B) Resistant Pica_Cis and FaDu_Cis cells show a lower number of cisplatin-induced DNA damage foci (γH2AX) compared to wt Pica/FaDu cells. Cells were treated with 20 µM cisplatin and analyzed by fluorescence microscopy after 24 h. Scale bar, 5 µm. (C) OSF-2 is not overexpressed in resistant Pica_Cis/FaDu_Cis versus sensitive wt cells. OSF-2 expression was quantified by RNASeq transcriptomics; relative mRNA expression is shown. (D) OSF-2 expression does not correlate with locoregional remission status after primary therapy (disease after curative treatment) in the TCGA HNC patient cohort. p-value and sample size (n) as indicated.