SAN DIEGO—Serum autoantibody profiling may provide a novel non-invasive diagnostic tool for bladder cancer, according to researchers at the Spanish National Cancer Research Center in Madrid.
Using high-throughput protein arrays with more than 12,000 proteins, Marta Sanchez-Carbayo, PhD, and her colleagues examined serum samples from 18 patients with bladder cancer and six control subjects. The control group included patients with other neoplasias, benign urological diseases, and healthy individuals.
It is theorized that cancer might release at least part of the protein into the bloodstream directly or through extracellular fluids upon cell damage or death.
Cancer proteins not present in non-neoplastic cell subpopulations might then elicit a host immune response, according to the researchers. If this is the case, it may be possible to develop serologic tools for early diagnosis and disease management.
The researchers, who presented findings here at the American Association for Cancer Research annual meeting, identified a panel of 171 autoantibodies in patients with bladder cancer that were expressed differently from the control group. These bladder cancer tumor-specific antigens (TAAs) included proteins linked to cell proliferation, signal transduction, apoptosis, DNA-binding, and transcriptions factors.
“The study has identified many bladder TAAs in the serum, representing a mirror of the bladder tumors,” said Dr. Sanchez-Carbayo. “Thus, autoantibody profiling represents a high-throughput approach for biomarker discovery and characterizing bladder cancer progression.”
Immunohistochemical analyses confirmed the increased protein expression of identified TAAs in bladder tumors. In addition, they highlighted the significance of protein expression patterns for bladder cancer diagnostics, tumor staging and prognosis. The researchers determined that clustering protein expression patterns were strongly linked to tumor size, T1 substaging or progression into muscle invasive disease.
“The novel application of high-throughput protein arrays for serum autoantibody profiling is also providing critical information to identify potential immunological therapeutic targets,” Dr. Sanchez-Carbayo said.