title: Functional proteomic analysis reveals the involvement of KIAA1199 in breast cancer growth, motility and invasiveness.
abstract: BACKGROUND
  KIAA1199 is a recently identified novel gene that is up-regulated in human cancer with poor survival. Our proteomic study on signaling polarity in chemotactic cells revealed KIAA1199 as a novel protein target that may be involved in cellular chemotaxis and motility. In the present study, we examined the functional significance of KIAA1199 expression in breast cancer growth, motility and invasiveness.
  
  
  METHODS
  We validated the previous microarray observation by tissue microarray immunohistochemistry using a TMA slide containing 12 breast tumor tissue cores and 12 corresponding normal tissues. We performed the shRNA-mediated knockdown of KIAA1199 in MDA-MB-231 and HS578T cells to study the role of this protein in cell proliferation, migration and apoptosis in vitro. We studied the effects of KIAA1199 knockdown in vivo in two groups of mice (n = 5). We carried out the SILAC LC-MS/MS based proteomic studies on the involvement of KIAA1199 in breast cancer.
  
  
  RESULTS
  KIAA1199 mRNA and protein was significantly overexpressed in breast tumor specimens and cell lines as compared with non-neoplastic breast tissues from large-scale microarray and studies of breast cancer cell lines and tumors. To gain deeper insights into the novel role of KIAA1199 in breast cancer, we modulated KIAA1199 expression using shRNA-mediated knockdown in two breast cancer cell lines (MDA-MB-231 and HS578T), expressing higher levels of KIAA1199. The KIAA1199 knockdown cells showed reduced motility and cell proliferation in vitro. Moreover, when the knockdown cells were injected into the mammary fat pads of female athymic nude mice, there was a significant decrease in tumor incidence and growth. In addition, quantitative proteomic analysis revealed that knockdown of KIAA1199 in breast cancer (MDA-MB-231) cells affected a broad range of cellular functions including apoptosis, metabolism and cell motility.
  
  
  CONCLUSIONS
  Our findings indicate that KIAA1199 may play an important role in breast tumor growth and invasiveness, and that it may represent a novel target for biomarker development and a novel therapeutic target for breast cancer.
authors.forename: Mohammad-Saeid
authors.initials: MS
authors.lastname: Jami
authors.forename: Jinxuan
authors.initials: J
authors.lastname: Hou
authors.forename: Miao
authors.initials: M
authors.lastname: Liu
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Varney
authors.forename: Hesham
authors.initials: H
authors.lastname: Hassan
authors.forename: Jixin
authors.initials: J
authors.lastname: Dong
authors.forename: Liying
authors.initials: L
authors.lastname: Geng
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.forename: Hong
authors.initials: H
authors.lastname: Peng
authors.forename: Kai
authors.initials: K
authors.lastname: Fu
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA. rsingh@unmc.edu.
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
authors.forename: Shi-Jian
authors.initials: SJ
authors.lastname: Ding
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D006821:Hyaluronoglucosaminidase; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness / Q000235:genetics*; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D040901:Proteomics
chemical_list: D014408:Biomarkers, Tumor; D011506:Proteins; C491433:CEMIP protein, human; D006821:Hyaluronoglucosaminidase