Enzyme Immunoassay for Serum Autoantibody to Survivin and Its Findings in Head-and-Neck Cancer Patients

Abstract

Several proteins associated with malignant transformation of cells can induce autoantibodies (1)(2)(3)(4). These autoantibodies, such as those to p53, are detectable in serum and may serve to monitor tumor progression (4)(5). Survivin, a recently cloned 16.5-kDa apoptosis inhibitor belonging to the IAP3 family (6), is expressed in the G2-M phase of the cell cycle (7). Its overexpression in cancer is thought to overcome an apoptotic checkpoint and favor aberrant progression of transformed cells through mitosis. Survivin is not produced in adult tissues except for the thymus and placenta, but it is abundantly produced in fetal tissues and in various human tumors, including lung, colon, gastric, breast, and bladder cancers as well as high-grade lymphomas (6)(7)(8)(9)(10). We developed an enzyme-labeled assay to measure anti-survivin autoantibody in sera and evaluated the relationship between anti-survivin and clinicopathologic variables. We obtained blood from 294 consecutive patients, before cancer treatment, at the Otorhinolaryngology or Head and Neck Surgery Clinics at Chang Gung Memorial Hospital with written informed consent. The standard treatment was radical surgery for early-stage patients, plus adjuvant radiotherapy for intermediate-risk patients, such as those with close surgical margins or lymph node metastases. Concomitant chemoradiotherapy was given to patients with lymph node metastases and extracapsular spread. All cancers were histologically graded as well-differentiated, moderately differentiated, or poorly differentiated, according to the WHO classification (11). Tumor pathology staging was classified according to the system of the American Joint Committee on Cancer (12). Blood samples from 40 gender- and age-matched healthy individuals were obtained as controls. After centrifugation, the sera were stored at −20 °C until use. Survivin cDNA was obtained by reverse transcription-PCR using total RNA from Jurkat cells with survivin-specific primers. The PCR product was ligated …