Abstract 390: Expression of the actin-binding protein Anillin is a prognostic biomarker for primary ER positive breast cancer.

Abstract

Abstract Identification of novel prognostic and predictive factors is important for individualizing prognosis and treatment for cancer patients. The present study aimed at examining the potential prognostic value of Anillin (ANLN) expression in breast cancer. ANLN, an actin-binding protein required for cytokinesis, was discovered using the Human Protein Atlas as being differentially expressed in breast cancer and, thus, a potential prognostic biomarker. The purpose of the Human Protein Atlas project (www.proteinatlas.org) is to generate validated antibodies towards the entire human proteome and to use these antibodies for protein profiling in normal tissues and cancer cells. The freely available Human Protein Atlas provides an opportunity to use antibody-based proteomics as a high-throughput strategy to discover novel cancer biomarkers of potential clinical relevance. ANLN has been shown to be up-regulated in several human tumor types including lung, renal and pancreatic tumors. For the purpose of the current study, tissue microarrays with tumor samples from three independent breast cancer cohorts were analyzed by immunohistochemistry (IHC). SiRNA mediated ANLN knockdown of breast cancer cell lines followed by western blot or IHC on cytospin was done for antibody validation. Cell viability assay and cell cycle assay was used to study the function of ANLN knocked breast cancer cells. The majority of breast tumors displayed moderate to strong nuclear positivity in slightly varying fractions, generally below 25%. High nuclear fraction of ANLN was associated with large tumor size, high histological grade, high proliferation and estrogen receptor (ER) negativity. Furthermore, high nuclear expression of ANLN was significantly associated with poor prognosis for patients with ER positive breast tumors in all three cohorts. SiRNA mediated ANLN knockdown was found to induce low cell viability for ER positive breast cancer cells but not for ER negative breast cancer cells. In addition, cell cycle studies showed that ANLN knockdown yielded a shift to G2/M phase, in both ER positive and ER negative breast cancer cells. In conclusion, our results strongly suggest that ANLN can be used as a prognostic biomarker for ER positive breast cancer patients. Citation Format: Kristina Magnusson, Gabriela Gremel, Fredrik Pontén, Karin Jirström. Expression of the actin-binding protein Anillin is a prognostic biomarker for primary ER positive breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 390. doi:10.1158/1538-7445.AM2013-390