title: Water bath hyperthermia reduces stemness of colon cancer cells.
abstract: OBJECTIVE
  Researchers have proposed that cancer stem cells (CSCs) are the driving force of tumorigenesis, recurrence, and metastases, contributing to the failure of some cancer treatments. Water bath hyperthermia, a novel treatment for cancer, can be highly effective when combined with chemotherapy, radiotherapy, or immunotherapy. Side population (SP) cells are part of a subpopulation of cells that have stem cell-like characteristics. In preliminary experiments, we discovered a decrease in SP cells in heat-treated colon cancer cells, which encouraged us to investigate whether hyperthermia had in fact played a role in regulating the stemness of colon cancer cells.
  
  
  METHODS
  We determined the number of SP cells and CD133-positive cells using flow cytometry; surveyed the expression of stemness-related genes and proteins by using quantitative reverse transcriptase-polymerase chain reaction and Western blot analysis, respectively; and evaluated tumor formation ability by using the tumor sphere formation assay.
  
  
  RESULTS
  We found that water bath hyperthermia at 40 °C results in a decreased percentage of SP cells (i.e. decreased from 0.6% to 0.0% and 1.1% to 0.1% among heat-treated HCT116 cells and SW620 cell respectively) and CD133-positive cells (i.e. decreased from 25.1 ± 1.2% to 18.7 ± 1.3% and 33.6 ± 3.2% to 23.5 ± 2.5% among heat-treated HCT116 cells and SW620 cell separately), weakens stem cell self-renewal properties (i.e., tumor colony formation ability), and downregulates the expression of stem-like cellular markers in colon cancer cells.
  
  
  CONCLUSIONS
  All the findings indicate that hyperthermia has an important effect on the stemness of colon cancer cells.
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China. Electronic address: gaofeidoc@163.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Ye
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianquan
authors.initials: J
authors.lastname: Yang
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000378:metabolism; D002452:Cell Count; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D048429:Cell Size; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology*; D015536:Down-Regulation / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D006979:Hyperthermia, Induced; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D010455:Peptides / Q000378:metabolism; D058985:Side-Population Cells / Q000473:pathology; D014867:Water
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D014867:Water
keywords: CD133; Colon cancer; Hyperthermia; SP cells; Stemness