title: Overexpression of sorcin in multidrug-resistant human breast cancer.
abstract: Sorcin is a soluble resistance-related calcium-binding protein, which is expressed in normal mammalian tissues, such as the liver, lungs and heart. It has been observed to be elevated in a number of cancer types, including colorectal, gastric and breast cancer. Its upregulation is usually associated with the development of chemotherapeutic drug resistance. The aim of this study was to evaluate the sorcin expression levels in human serum samples of breast cancer subjects at various stages, and subsequently compare the outcome of neoadjuvant chemotherapy when the sorcin levels fluctuated. In total, 50 subjects were recruited from patients who were admitted to Yantai Yuhunagding Hospital (Yantai, China) and diagnosed with breast cancer. Blood samples prior to and following chemotherapy were assessed using two-dimensional gel electrophoresis (2-DE) and western blot analysis. The 2-DE analysis of the serum samples revealed that sorcin was upregulated in six out of 29 neoadjuvant chemotherapy (NAC)-sensitive patients and, in those who developed multidrug resistance, sorcin was upregulated in 15 out of 21 patients (P<0.01). The differential expression levels of sorcin were confirmed by western blot and immunohistochemical analysis. In conclusion, sorcin expression in the human serum of breast cancer patients who are resistant to NAC was elevated when compared with that of NAC-sensitive patients.
authors.affiliation: Department of Oncology, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Gong
authors.affiliation: Department of Oncology, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.affiliation: Central Laboratory, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Hongjin
authors.initials: H
authors.lastname: Chu
authors.affiliation: Department of Oncology, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Oncology, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Dengjun
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Oncology, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China ; Central Laboratory, Yantai Yuhuangding Hospital Affiliated to Qingdao University, Yantai, Shandong 264000, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
keywords: breast cancer; neoadjuvant chemotherapy; sorcin