Yanjing Huang1, Shenghui Yang1, Weiling Yu2, Ling Gui3. 1. Department of Medical Oncology, Hainan General Hospital Affiliated to Hainan Medical University, Haikou, 570311, Hainan, China. 2. Department of Medical Oncology, Haikou City People's Hospital, Haikou, 570208, Hainan, China. 3. Department of Pharmacy, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. guling_wh@outlook.com.
Abstract
PURPOSE: To assess the potential role of nuclear auto-antigenic sperm protein (NASP) in the cellular sensitivity to 5-Fluorouracil (5-FU) in breast cancer cells. METHODS: The expression of two NASP isotypes, namely somatic NASP (sNASP) and testis NASP (tNASP) in breast cancer lines were detected under 5-FU treatment using real-time polymerase chain reaction and western blot assays. NASP effect on cellular viability and apoptosis under 5-FU treatment were evaluated. The interaction between NASP and its downstream proteins were evaluated using the co-immunoprecipitation (Co-IP) assays. RESULTS: 5-FU significantly decreased the mRNA and protein expression levels of sNASP. Inhibition of sNASP increased cellular viability, colony formation ability, but reduced apoptosis in tested cell lines in response to 5-FU, which were reversed by sNASP over-expression. Further study reveals 5-FU disrupts sNASP/TNF receptor-associated factor 6 (TRAF6) complex, potentiates cellular sensitivity to 5-FU via NK-kB. CONCLUSION: Our findings suggest sNASP is a novel molecular target having potential to overcome the resistance to 5-FU in breast cancer cells.
PURPOSE: To assess the potential role of nuclear auto-antigenic sperm protein (NASP) in the cellular sensitivity to 5-Fluorouracil (5-FU) in breast cancer cells. METHODS: The expression of two NASP isotypes, namely somatic NASP (sNASP) and testis NASP (tNASP) in breast cancer lines were detected under 5-FU treatment using real-time polymerase chain reaction and western blot assays. NASP effect on cellular viability and apoptosis under 5-FU treatment were evaluated. The interaction between NASP and its downstream proteins were evaluated using the co-immunoprecipitation (Co-IP) assays. RESULTS: 5-FU significantly decreased the mRNA and protein expression levels of sNASP. Inhibition of sNASP increased cellular viability, colony formation ability, but reduced apoptosis in tested cell lines in response to 5-FU, which were reversed by sNASP over-expression. Further study reveals 5-FU disrupts sNASP/TNF receptor-associated factor 6 (TRAF6) complex, potentiates cellular sensitivity to 5-FU via NK-kB. CONCLUSION: Our findings suggest sNASP is a novel molecular target having potential to overcome the resistance to 5-FU in breast cancer cells.
Authors: Richard T Richardson; Oleg M Alekseev; Gail Grossman; Esther E Widgren; Randy Thresher; Eric J Wagner; Kelly D Sullivan; William F Marzluff; Michael G O'Rand Journal: J Biol Chem Date: 2006-05-25 Impact factor: 5.157