P034 Detection of soluble HLA antigens (sHLA) in blood for early detection of non-small cell lung carcinoma (NSCLC)

Aim Non-small and small cell lung cancer (NSCLC and SCLC) is the leading cause of cancer-related deaths worldwide. Early detection and appropriate intervention are critical for successful treatment. Current screening methods cannot clearly distinguish between benign and malignant nodules. The human histocompatibility antigens (HLA), which control the immune response, can be crucial in escape from tumor immune surveillance resulting in tumor progression and metastasis. Increased HLA levels in circulation of cancer patients have been detected in the past. Therefore, the aim was to determine circulating HLA antigens could serve as potential biomarkers to distinguish between benign and malignant lung cancer nodules. Methods HLA class I (ABC) and class II (DRB1 and DQ) antigen levels were analyzed in cell lines and conditioned media of epithelial H358 and mesenchymal H1703. Then, serum samples from 25 patients with benign nodules (non-invasive cells) and 25 patients with malignant nodule (Stage I NSCLC-with invasive cells) were analyzed for HLA-class I (ABC), HLA-class II (DRB1, DQA1, DQ, DMB) antigens in their serum. Equal amounts of total proteins from each group were used for comparison of HLA antigen levels. Western Blot with Chemiluminiscence detection system was used for evaluating HLA antigen levels in samples. Results A significantly higher level of HLA class I antigens was observed in conditioned medium from the invasive cell line compared to conditioned medium from non-invasive cell line ( p p Conclusion In-vitro studies using non-invasive and invasive cell lines showed significantly increased levels of HLA-class I in conditioned medium obtained from the invasive cell line compared to the non-invasive cell line. The Mann–Whitney Rank Sum Test showed significant differences in the serum levels of HLA-ABC, DQA1, HLA-DQ, HLA-DRB1, HLA-DMB, between patients with benign nodule and Stage I NSCLC patients. These preliminary data suggest that levels of HLA class I and class II antigens could act as potential biomarkers to diagnose early stages of NSCLC.