Mouse Anti-Human CA 125 monoclonal antibody, clone Y417

Cancer antigen 125 (CA125) is a coelomic epithelium-related antigen carried by a high molecular weight glycoprotein complex. It is commonly used as a tumor marker for ovarian cancer to monitor disease progression and response to therapy and as an early detection for recurrence after treatment. The aim of this study was to test the reliability of two different assay methods, a radioimmunometric assay (RIA) and an automated chemiluminescent enzyme immunoassay (CLEIA) system, by measuring CA125 serum levels using both methods in 357 patients and comparing the results. Patients were recruited from Oncologic Unit A, Policlinico Umberto I, Roma. Eighty-six were healthy donors, while 271 were oncologic patients representing a variety of diagnoses. Within this group, 76 patients were diagnosed with an ovarian related pathology (28 cancerous and 48 benign). The evaluation of CA125 marker blood levels showed a high agreement in healthy donors group (R (2) = 0.9003). Interesting results emerged when sera collected from oncologic patients were assessed: significant differences between the two assays were found in nine samples. When assayed again with RIA after a dilution, new values agreed with undiluted CLEIA values (R (2) = 0.9847). Our data suggest an overall good comparison between the two methods. However, some artifacts were obtained with RIA and indicate an underlying presence of "hook effect". CLEIA automated assay showed a good reliability and should be preferred to one-step radioimmunoassays in order to minimize errors.

Human papilloma virus-16 (HPV-16) associated oropharyngeal cancer (HPVOPC) is increasing alarmingly in the United States. We performed whole genome sequencing of a 44 year old, male HPVOPC subject diagnosed with moderately differentiated tonsillar carcinoma. We identified new somatic mutation in MUC16 (A.k.a. CA-125), MUC12, MUC4, MUC6, MUC2, SIRPA, HLA-DRB1, HLA-A and HLA-B molecules. Increased protein expression of MUC16, SIRPA and decreased expression of HLA-DRB1 was further demonstrated in this HPVOPC subject and an additional set of 15 HPVOPC cases. Copy number gain (3 copies) was also observed for MUC2, MUC4, MUC6 and SIRPA. Enhanced expression of MUC16, SIRPA and HPV-16-E7 protein was detectable in the circulating exosomes of numerous HPVOPC subjects. Treatment of non-tumorigenic mammary epithelial cells with exosomes derived from aggressive HPVOPC cells harboring MUC16, SIRPA and HPV-16-E7 proteins augmented invasion and induced epithelial to mesenchymal transition (EMT) accompanied by an increased expression ratio of the EMT markers Vimentin/E-cadherin. Exosome based screening of key HPVOPC associated molecules could be beneficial for early cancer diagnosis, monitoring and surveillance.