Potential Biomarker Found for Aggressive Breast Carcinoma

Scientists at Stony Brook University School of Medicine, (Stony Brook, NY, USA), analyzed the SCCA expression on 1,360 breast tumor tissue samples and 124 samples of normal breast tissue as controls. They used various techniques including immunoblot analysis, tissue microarrays, and immunohistochemistry. Expression of SCCA was observed in only 0.3% of grade 1 tumors, but increased to 2.5% and 9.4% in grades 2 and 3 tumors, respectively. For the various stages of breast cancer in nonmetastatic disease, the progression was similar. Positivity for SCCA was documented in 2.4% of Stage I cancers, 3.1% of Stage II cancers, and 8.6% of Stage III cancers.

Squamous cell carcinoma antigen belongs to the serine protease inhibitor (Serpin) family of proteins and is an inhibitor of cellular proteases that digests other proteins. Elevated expression of SCCA has been used in medicine as a biomarker for aggressive squamous-cell carcinoma in cancers of the cervix, lung, and head and neck. Its expression has also been detected in cancers that are not originated from squamous cells such as liver cancer. The scientists also found that SCCA-expressing cells are specifically sensitive to drugs that induce misfolded proteins.

Wei-Xing Zong, PhD, associate professor and a senior author of the study, said, "While there has been significant progress in treating breast cancer, aggressive disease remains difficult to treat and cure. Our findings open the door for SCCA to be explored as a useful marker for predicting outcomes of those suffering from aggressive breast cancers and for SCCA to become a potential therapeutic target to treat cancers unresponsive to current therapies." The study was published online on April 19, 2011, in Public Library of Science ONE (PLoS ONE).

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