title: Sensitivity of neoplastic cells to senescence unveiled under standard cell culture conditions.
abstract: BACKGROUND
  Cancer cells are typically defined as infinitely proliferating, whereas normal cells (except stem cells) are considered as being programmed to become senescent. Our data show that this characterization is misleading.
  
  
  METHODS
  Multiplex Ligation-dependent Probe Amplification, TP53 sequencing, real-time polymerase chain reaction (PCR) for MUC1 and SCGB2A2 and immunocytochemistry, together with senescence detection assay and real-time microscopic observations were used to analyze primary neoplastic cells isolated from prostate, breast and colorectal tumors, as well as stable cancer cell lines (MCF7, MDA-MB-468, SW962, SK-MEL28, NCI-H1975 and NCI-H469).
  
  
  RESULTS
  In all cases of primary cancer cell cultures, in vitro conditions rapidly revealed senescence in the majority of cells. Two out of six stable cancer cell lines did not exhibit any senescence-associated-β-Galactosidase-positive cells. Interestingly, four cell lines had small sub-populations of senescent cells (single SA-β-Gal-positive cells).
  
  
  CONCLUSIONS
  Primary neoplastic cells from different types of cancer (prostate, breast, colon cancer) appear to be senescent in vitro. Apparently, cancer cell lines that have been used for many years in drug-testing analyses have constantly been misleading researchers in terms of the general sensitivity of cancer cells to senescence.
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland jolanta.zieba@stud.umed.lodz.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Zieba
authors.affiliation: Department of Research and Development, Celther Polska, Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Ksiazkiewcz
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Janik
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Banaszczyk
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Peciak
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Sylwester
authors.initials: S
authors.lastname: Piaskowski
authors.affiliation: Clinic II of Urology, Medical University of Lodz, Lodz, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Lipinski
authors.affiliation: Clinic II of Urology, Medical University of Lodz, Lodz, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Olczak
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Stoczynska-Fidelus
authors.affiliation: Department of Tumor Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Rieske
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D016922:Cellular Senescence / Q000187:drug effects / Q000235:genetics*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008297:Male; D060785:Mammaglobin A / Q000096:biosynthesis; D018396:Mucin-1 / Q000096:biosynthesis; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology
chemical_list: C060192:MUC1 protein, human; D060785:Mammaglobin A; D018396:Mucin-1; C556448:SCGB2A2 protein, human
keywords: Senescence; cancer cell line; oncogene-induced senescence; primary cell culture; senescence-associated heterochromatin foci; senescence-associated β-galactosidase