title: Down regulation of SPAG9 reduces growth and invasive potential of triple-negative breast cancer cells: possible implications in targeted therapy.
abstract: BACKGROUND
  Recently, we reported an association of a novel cancer testis (CT) antigen, sperm-associated antigen 9 (SPAG9) expression in breast cancer clinical samples, indicating its potential role in carcinogenesis. Around 15% breast cancers are designated as triple-negative for which treatment modalities are limited. Therefore, in the present study, we assessed the role of SPAG9 in triple-negative breast cancer cells.
  
  
  METHODS
  SPAG9 mRNA and protein expression was investigated in various breast cancer cells of different hormone receptor status and different subtypes by employing reverse transcriptase-polymerase chain reaction (RT-PCR), real time PCR, Western blotting, indirect immunofluorescence (IIF) and fluorescence activated cell sorting (FACS). Employing plasmid-based small interfering RNA (siRNA) approach, knockdown of SPAG9 was carried out in triple-negative breast cancer cells, MDA-MB-231, to assess its role on various malignant properties in vitro and in vivo.
  
  
  RESULTS
  SPAG9 mRNA and protein expression was detected in all breast cancer cells. Further, IIF results showed that SPAG9 was predominantly localized in the cytoplasm of breast cancer cells. FACS analysis revealed distinct SPAG9 surface localization in breast cancer cells. Gene silencing of SPAG9 resulted in significant reduction in cellular proliferation, colony forming ability, migration, invasion and cellular motility of MDA-MB-231 cells. Further, ablation of SPAG9 expression resulted in reduction in the tumor growth of human breast cancer xenograft in nude mice in vivo.
  
  
  CONCLUSIONS
  In summary, our data indicated that down regulation of SPAG9 reduces growth and invasive potential of triple-negative breast cancer cells, suggesting that SPAG9 may be a potential target for therapeutic use.
authors: Abhilasha
authors: A
authors: Sinha
authors: Sumit
authors: S
authors: Agarwal
authors: Deepak
authors: D
authors: Parashar
authors: Archana
authors: A
authors: Verma
authors: Shikha
authors: S
authors: Saini
authors: Nirmala
authors: N
authors: Jagadish
authors: Abdul S
authors: AS
authors: Ansari
authors: Nirmal K
authors: NK
authors: Lohiya
authors: Anil
authors: A
authors: Suri
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D015536:Down-Regulation; D020868:Gene Silencing; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D064726:Triple Negative Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D023041:Xenograft Model Antitumor Assays
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D034741:RNA, Small Interfering; C111047:SPAG9 protein, human