Novel Tumor Markers in Non-Small Cell Lung Cancer Detected Both in Serology and Tissue.

e21105 Background: Cancer testis antigens (CTA) are a class of tumor associated antigens, showing a restricted expression in cancer, a strong immunogenicity and weak expression or absence in normal tissues. CTA are a growing family of proteins involved in signal transduction control. Sp17/AKAP4/PTTG1 have been previously investigated, showing promising results as a target antigens. Our aim was to investigate the expression of Sp17/AKAP4/PTTG1 in lung cancer patients. Methods: We analyzed 2 lung cancer cell lines, one normal bronchus cell line, a panel of normal tissues and patient’s cells by RT-PCR, flow-cytometry, immunocytochemistry (ICC), and immunofluorescence (IF). CTA immunogenicity was investigated by measuring circulating specific antibodies in the sera of lung cancer patients. PCR was performed by 35 amplification cycles. RNA integrity in each sample was checked by amplification of ß-actin. We studied the pattern of expression in patients with NSCLC according to histology, gender, and age. Results: Specimens from 11 patients were examined.CTA, Sp17, AKAP-4 and PTTG-1 are aberrantly expressed in lung cancer cell lines and primary cells from patients by RT-PCR, immunocytochemistry, and flow cytometry. ELISA analyses show the presence of circulating CTA-specific antibodies in the sera of lung cancer patients, indicating the immunogenicity of Sp17, AKAP-4 and PTTG-1. The mean age of patients was 60 years(range 57-76). Fifty eight percent were males(N=7). Seventy two percent (n=8) had adenocarcinoma. Six patients were stage IV at diagnosis. There was no difference in the pattern of expression between gender, stage or histology. Conclusions: We showed that CTA, Sp17, AKAP-4 and PTTG-1 can be detected in both sera and tissue of patients with NSCLC. They are potential therapeutic targets for immunotherapies. These may me useful in determining response to treatment as well as asses possible recurrence.