title: Evidence of distinct tumour-propagating cell populations with different properties in primary human hepatocellular carcinoma.
abstract: OBJECTIVE
  Increasing evidence that a number of malignancies are characterised by tumour cell heterogeneity has recently been published, but there is still a lack of data concerning liver cancers. The aim of this study was to investigate and characterise tumour-propagating cell (TPC) compartments within human hepatocellular carcinoma (HCC).
  
  
  METHODS
  After long-term culture, we identified three morphologically different tumour cell populations in a single HCC specimen, and extensively characterised them by means of flow cytometry, fluorescence microscopy, karyotyping and microarray analyses, single cell cloning, and xenotransplantation in NOD/SCID/IL2Rγ/⁻ mice.
  
  
  RESULTS
  The primary cell populations (hcc-1, -2 and -3) and two clones generated by means of limiting dilutions from hcc-1 (clone-1/7 and -1/8) differently expressed a number of tumour-associated stem cell markers, including EpCAM, CD49f, CD44, CD133, CD56, Thy-1, ALDH and CK19, and also showed different doubling times, drug resistance and tumorigenic potential. Moreover, we found that ALDH expression, in combination with CD44 or Thy-1 negativity or CD56 positivity identified subpopulations with a higher clonogenic potential within hcc-1, hcc-2 and hcc-3 primary cell populations, respectively. Karyotyping revealed the clonal evolution of the cell populations and clones within the primary tumour. Importantly, the primary tumour cell population with the greatest tumorigenic potential and drug resistance showed more chromosomal alterations than the others and contained clones with epithelial and mesenchymal features.
  
  
  CONCLUSIONS
  Individual HCCs can harbor different self-renewing tumorigenic cell types expressing a variety of morphological and phenotypical markers, karyotypic evolution and different gene expression profiles. This suggests that the models of hepatic carcinogenesis should take into account TPC heterogeneity due to intratumour clonal evolution.
authors: Experimental Hepatology Laboratory, Centre of Transfusion Medicine, Cellular Therapy and Cryobiology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. labcitofl@policlinico.mi.it
authors: Federico
authors: F
authors: Colombo
authors: Francesca
authors: F
authors: Baldan
authors: Silvia
authors: S
authors: Mazzucchelli
authors: Ines
authors: I
authors: Martin-Padura
authors: Paola
authors: P
authors: Marighetti
authors: Alessandra
authors: A
authors: Cattaneo
authors: Barbara
authors: B
authors: Foglieni
authors: Marta
authors: M
authors: Spreafico
authors: Silvana
authors: S
authors: Guerneri
authors: Marco
authors: M
authors: Baccarin
authors: Francesco
authors: F
authors: Bertolini
authors: Giorgio
authors: G
authors: Rossi
authors: Vincenzo
authors: V
authors: Mazzaferro
authors: Massimiliano
authors: M
authors: Cadamuro
authors: Marco
authors: M
authors: Maggioni
authors: Luca
authors: L
authors: Agnelli
authors: Paolo
authors: P
authors: Rebulla
authors: Daniele
authors: D
authors: Prati
authors: Laura
authors: L
authors: Porretti
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000473:pathology*; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002999:Clone Cells; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000494:pharmacology / Q000627:therapeutic use; D008113:Liver Neoplasms / Q000188:drug therapy / Q000473:pathology*; D051379:Mice; D008856:Microscopy, Fluorescence; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011758:Pyrroles / Q000494:pharmacology / Q000627:therapeutic use; D000077210:Sunitinib; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib