title: Modulating drug resistance by targeting BCRP/ABCG2 using retrovirus-mediated RNA interference.
abstract: BACKGROUND
  The BCRP/ABCG2 transporter, which mediates drug resistance in many types of cells, depends on energy provided by ATP hydrolysis. Here, a retrovirus encoding a shRNA targeting the ATP-binding domain of this protein was used to screen for highly efficient agents that could reverse drug resistance and improve cell sensitivity to drugs, thus laying the foundation for further studies and applications.
  
  
  RESULTS
  To target the ATP-binding domain of BCRP/ABCG2, pLenti6/BCRPsi shRNA recombinant retroviruses, with 20 bp target sequences starting from the 270th, 745th and 939th bps of the 6th exon, were constructed and packaged. The pLenti6/BCRPsi retroviruses (V-BCRPi) that conferred significant knockdown effects were screened using a drug-sensitivity experiment and flow cytometry. The human choriocarcinoma cell line JAR, which highly expresses endogenous BCRP/ABCG2, was injected under the dorsal skin of a hairless mouse to initiate a JAR cytoma. After injecting V-BCRPi-infected JAR tumor cells into the dorsal skin of hairless mice, BCRP/ABCG2 expression in the tumor tissue was determined using immunohistochemistry, fluorescent quantitative RT-PCR and Western blot analyses. After intraperitoneal injection of BCRP/ABCG2-tolerant 5-FU, the tumor volume, weight change, and apoptosis rate of the tumor tissue were determined using in situ hybridization. V-BCRPi increased the sensitivity of the tumor histiocytes to 5-FU and improved the cell apoptosis-promoting effects of 5-FU in the tumor.
  
  
  CONCLUSIONS
  The goal of the in vivo and in vitro studies was to screen for an RNA interference recombinant retrovirus capable of stably targeting the ATP-binding domain of BCRP/ABCG2 (V-BCRPi) to inhibit its function. A new method to improve the chemo-sensitivity of breast cancer and other tumor cells was discovered, and this method could be used for gene therapy and functional studies of malignant tumors.
authors: Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China.
authors: Ni
authors: N
authors: Xie
authors: Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China.
authors: Lisha
authors: L
authors: Mou
authors: The Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong, China.
authors: Jianhui
authors: J
authors: Yuan
authors: Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China.
authors: Wenlan
authors: W
authors: Liu
authors: The Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong, China.
authors: Tingting
authors: T
authors: Deng
authors: The Shenzhen Graduate School, Peking University, Shenzhen, Guangdong, China.
authors: Zigang
authors: Z
authors: Li
authors: Yi
authors: Y
authors: Jing
authors: Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China.
authors: Yi
authors: Y
authors: Jin
authors: College of Life Science, Shenzhen University, Shenzhen, Guangdong, China.
authors: Zhangli
authors: Z
authors: Hu
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005472:Fluorouracil / Q000494:pharmacology / Q000627:therapeutic use; D005822:Genetic Vectors / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D014183:Transplantation, Heterologous
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D034741:RNA, Small Interfering; D005472:Fluorouracil