Expression of Glypican-3 (GPC3) in Malignant and Non-malignant Human Breast Tissues

Specific reports have linked GPC3 with cancer. Its usefulness as a marker has been proved for hepatocarcinoma, melanoma and ovary carcinoma. However, there are no studies analyzing GPC3 usefulness as a biomarker in mammary tumors. The aim of this work was to analyze GPC3 expression in breast tissues and to determine whether it might be useful as a biomarker in breast cancer patients. Expression level of GPC3 mRNA in Brazilian and Argentine human breast tumor (n=121) and peritumoral "normal" tissue (n=77) samples was analyzed using qRT-PCR. GPC3 protein expression was analyzed from 69 breast cancer and 10 peritumoral samples using IHC. Statistical analyses were done to evaluate the clinical-pathological significance of GPC3 expression. We found that Brazilian and Argentine populations are statistically different regarding GPC3 mRNA expression. In Argentine patients a lower GPC3 mRNA expression was found in tumors as compared to peritumoral tissues. No association was found between GPC3 mRNA and protein expression and the clinical-pathological parameters. The Kaplan-Meier curves suggested that elevated levels of GPC3 mRNA are associated with relapse. Our results indicate differential expression of GPC3 in mammary tumors in comparasion to normal breast tissues. They also suggest the potential role of GPC3 as a biomarker and the importance of deepening the study.