Abstract Background: HNSCC has significant burden with high morbidity and mortality. Majority of the HNSCC patients receive Radiotherapy (RT), which is associated with development of radiation resistance and disease-recurrence, which needs in-depth evaluation. Lipocalin2(LCN2), found to be dysregulated in the saliva of HNSCC patients in our previous study using LC/MS shotgun proteomics, is also found associated with radio resistance (RR). To establish the potential role as a predictor of RR, we evaluated LCN2 in HNSCC patients. Methodology: 356 biopsy-proven treatment-naïve HNSCC, 26 Oral Pre-Malignant Diseases (OPMDs) and 118 healthy subjects were recruited for the study. The patients were treated with curative intent with 66Gy of RT. 5ml of unstimulated saliva and 3ml of whole blood were collected at baseline and during follow-ups in No evidence of disease (NED) and Residual Disease (RD)patients post therapy completion. To evaluate the role LCN2 as a marker of RR, radioresistant cells were generated by repeated sub-lethal exposure of Cal27 cells to γ-rays from radioactive Co60. The RR phenotype was confirmed by phosphorylated H2AX(γH2AX) expression using Western Blot (WB) and Immunofluorescence (IF). Various RR assays such as clonogenic survival assay, apoptosis assay and cell cycle analysis, were performed on the successfully generated RR cells, which were later analysed for the expression of LCN2. Results: Significantly higher(p≤0.0001) levels of LCN2 in saliva and serum (median- 609.15ng/ml Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7365.
Suri et al. (Fri,) studied this question.