D Meng1, Q Yu1,2, L Feng1, M Luo1,3, S Shao1, S Huang1, G Wang1, X Jing1, Z Tong4, X Zhao5, R Liu6,7. 1. Department of Oncology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277# Yanta west Road, Xi'an, 710061, Shaanxi, People's Republic of China. 2. Department of Radiation Oncology, Puyang People's Hospital, Puyang, 457000, Henan, People's Republic of China. 3. Department of Hematology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China. 4. School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China. 5. Department of Oncology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277# Yanta west Road, Xi'an, 710061, Shaanxi, People's Republic of China. zhaoxinhanprof@163.com. 6. Department of Oncology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277# Yanta west Road, Xi'an, 710061, Shaanxi, People's Republic of China. reon10@sina.com. 7. Department of Radiation Oncology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China. reon10@sina.com.
Abstract
OBJECTIVES: Citron kinase (CIT-K), as a key Rho effector, functions to maintain proper structure of the midbody during cell mitosis. This study assessed CIT-K expression and its role in breast cancer cells. METHODS: Paraffin-embedded breast cancer and para-tumor tissues from 43 invasive breast cancer patients and 33 normal mammary glands were collected for immunohistochemistry. CIT-K expression knockdown was achieved using lentivirus carrying CIT-K shRNA in a wide range of breast cancer cell lines. Cells were then subjected to Western blot, qRT-PCR, cell proliferation, colony formation, transwell, and flow cytometric assays. The tumorigenicity of CIT-K knocked-down breast cancer cells was assessed using the nude mouse xenograft assay. Microarray analysis was performed to elucidate the underlying gene regulation after CIT-K silencing. RESULTS: CIT-K protein was overexpressed in breast cancer tissues, which is associated with advanced tumor stage, HER-2 expression and Ki-67 expression, whereas knockdown of CIT-K expression reduced breast cancer cell proliferation and colony formation, but promoted tumor cell apoptosis and cell-cycle arrest. Knockdown of CIT-K expression also inhibited breast cancer cell migration and invasion capacity. Moreover, CIT-K knockdown suppressed the tumorigenicity of breast cancer cells in nude mice. Molecularly, the expression of a variety of signaling genes, such as cyclin D1, EGFR, JAK1, TGF-α, PTK2, RAF1, RALB, SOS1, mTOR, and PTGS2, were altered after CIT-K knockdown. CONCLUSIONS: This study demonstrated that CIT-K is associated with aggressive breast cancer behavior and targeting CIT-K may be a novel strategy for the future control of breast cancer.
OBJECTIVES:Citron kinase (CIT-K), as a key Rho effector, functions to maintain proper structure of the midbody during cell mitosis. This study assessed CIT-K expression and its role in breast cancer cells. METHODS:Paraffin-embedded breast cancer and para-tumor tissues from 43 invasive breast cancerpatients and 33 normal mammary glands were collected for immunohistochemistry. CIT-K expression knockdown was achieved using lentivirus carrying CIT-K shRNA in a wide range of breast cancer cell lines. Cells were then subjected to Western blot, qRT-PCR, cell proliferation, colony formation, transwell, and flow cytometric assays. The tumorigenicity of CIT-K knocked-down breast cancer cells was assessed using the nude mouse xenograft assay. Microarray analysis was performed to elucidate the underlying gene regulation after CIT-K silencing. RESULTS:CIT-K protein was overexpressed in breast cancer tissues, which is associated with advanced tumor stage, HER-2 expression and Ki-67 expression, whereas knockdown of CIT-K expression reduced breast cancer cell proliferation and colony formation, but promoted tumor cell apoptosis and cell-cycle arrest. Knockdown of CIT-K expression also inhibited breast cancer cell migration and invasion capacity. Moreover, CIT-K knockdown suppressed the tumorigenicity of breast cancer cells in nude mice. Molecularly, the expression of a variety of signaling genes, such as cyclin D1, EGFR, JAK1, TGF-α, PTK2, RAF1, RALB, SOS1, mTOR, and PTGS2, were altered after CIT-K knockdown. CONCLUSIONS: This study demonstrated that CIT-K is associated with aggressive breast cancer behavior and targeting CIT-K may be a novel strategy for the future control of breast cancer.
Entities:
Keywords:
Breast cancer; CIT-K; Gene knockdown; Tumorigenicity