title: Elevated Krüppel-like factor 4 transcription factor in canine mammary carcinoma.
abstract: BACKGROUND
  Krüppel-like factors (KLFs) are critical regulators of biological and physiological systems and have been extensively studied for their roles in cell proliferation, differentiation and survival in the context of cancer. Among the KLFs, KLF4 is highly expressed in human breast cancers and plays an oncogenic role. The present study examined the expression of KLF4 and assessed its significance in canine mammary carcinoma.
  
  
  RESULTS
  Immunohistochemistry was employed to investigate the expression of KLF4 in 142 cases of canine mammary tumor. 75 of the 142 (52.8%) cases were histologically confirmed as mammary carcinoma. Quantification of immunohistochemistry was carried out using Quick score which multiply the staining intensity by the percentage of positive cells. High KLF4 expression was identified in 44 of the 75 (59%) dogs with mammary carcinoma and none in the benign cases. High KLF4 expression occurred only in the tumor cells and not the adjacent normal cells in mammary carcinoma (P < 0.001). Moreover, the high expression level of KLF4 expression was statistically associated with poor grade, late stage, histological subtypes of simple and complex carcinoma, and shorter 24-month survival. The Kaplan-Meier survival analysis also indicated that dogs with high nuclear KLF4 expression had a significantly shorter survival than those with low/moderate KLF4 expression (P = 0.011).
  
  
  CONCLUSIONS
  KLF4 is highly and frequently expressed in canine mammary carcinoma and correlates with a more aggressive phenotype.
authors: Department and Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, No, 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan.
authors: Pei-Yi
authors: PY
authors: Chu
authors: Nicholas Chung-Heng
authors: NC
authors: Hsu
authors: Albert Taiching
authors: AT
authors: Liao
authors: Kun-Tu
authors: KT
authors: Yeh
authors: Ming-Feng
authors: MF
authors: Hou
authors: Chen-Hsuan
authors: CH
authors: Liu
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000473:pathology; D015674:Mammary Neoplasms, Animal / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype
chemical_list: C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors