title: Differential expression of aristaless-like homeobox 4: a potential marker for gastric adenocarcinoma.
abstract: OBJECTIVE
  The objective of this experiment was to evaluate the ALX-4 mRNA expression level in different stages of human gastric adenocarcinoma compared to the gastric cancer stem cells (GCSC) and gastric cancer cell line, MKN-45.
  
  
  BACKGROUND
  Gastric cancer is the second most common cancer in the world today, leading approximately to 3-10% of all cancer-related deaths. Identification of specific biomarkers could be a crucial approach to improve diagnosis and treatment of this cancer type. Recent findings emphasized on the up-regulation ofAristaless-Like Homeobox 4(ALX-4) gene expression in several tumors.
  
  
  METHODS
  MKN-45 cell culture was prepared, and gastric cancer stem cell (GCSC) isolation was performed by flowcytometry. Then, 37 fresh gastric tissue samples from cancer patient were subjected for expression analysis by quantitative RT-PCR, prior to any therapeutic intervention in the comparative study for evaluation ofALX-4gene expression.
  
  
  RESULTS
  GCSCs with cuboidal shape as well as a positive expression of CD105, CD44, CD90 and negative for CD45, CD34 markers were identified. Overexpression ofALX-4was detected in 46% (3.351±2.94, P<0.05) of gastric cancer tissue specimens and GCSCs (4.31±0.04, P<0.005). The mRNA expression level ofALX-4in MKN-45 gastric cancer cell line was 2.81±0.07 (P<0.005). We determined thatALX-4mRNA level significantly correlated with the tumor grade (P=0.004), stage (p=0.000153), but not gender (P= 0.06).
  
  
  CONCLUSIONS
  These results documented the important role ofALX-4in GCSCs, as an oncogene in progressive cancer, and valuable target in the treatment of drug resistant tumors.
authors.affiliation: Enzyme Technology Lab, Genetics & Metabolism Research Group, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Fariba
authors.initials: F
authors.lastname: Ghasemvand
authors.affiliation: Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Navid
authors.initials: N
authors.lastname: Nezafat
authors.affiliation: Department of Biology, Garmsar Branch, Islamic Azad University, Garmsar, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Hesami Tackallou
authors.affiliation: Brain and Spinal Injury Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Daruosh
authors.initials: D
authors.lastname: Momenzadeh
authors.affiliation: Enzyme Technology Lab, Genetics & Metabolism Research Group, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Saeid
authors.initials: S
authors.lastname: Rahmanzadeh
keywords: ALX-4; Cancer stem cell; MKN-45; qRT-PCR