title: Transdifferentiation of MALME-3M and MCF-7 Cells toward Adipocyte-like Cells is Dependent on Clathrin-mediated Endocytosis.
abstract: Enforced cell transdifferentiation of human cancer cells is a promising alternative to conventional chemotherapy. We previously identified albumin-associated lipid- and, more specifically, saturated fatty acid-induced transdifferentiation programs in human cancer cells (HCCLs). In this study, we further characterized the adipocyte-like cells, resulting from the transdifferentiation of human cancer cell lines MCF-7 and MALME-3M, and proposed a common mechanistic approach for these transdifferentiating programs. We showed the loss of pigmentation in MALME-3M cells treated with albumin-associated lipids, based on electron microscopic analysis, and the overexpression of perilipin 2 (PLIN2) by western blotting in MALME-3M and MCF-7 cells treated with unsaturated fatty acids. Comparing the gene expression profiles of naive melanoma MALME-3M cells and albumin-associated lipid-treated cells, based on RNA sequencing, we confirmed the transcriptional upregulation of some key adipogenic gene markers and also an alternative splicing of the adipogenic master regulator PPARG, that is probably related to the reported up regulated expression of the protein. Most importantly, these results also showed the upregulation of genes responsible for Clathrin (CLTC) and other adaptor-related proteins. An increase in CLTC expression in the transdifferentiated cells was confirmed by western blotting. Inactivation of CLTC by chlorpromazine (CHP), an inhibitor of CTLC mediated endocytosis (CME), and gene silencing by siRNAs, partially reversed the accumulation of neutral lipids observed in the transdifferentiated cells. These findings give a deeper insight into the phenotypic changes observed in HCCL to adipocyte-like transdifferentiation and point towards CME as a key pathway in distinct transdifferentiation programs.
  
  
  BACKGROUND
  Simon C and Aguilar-Gallardo C are co-inventors of the International Patent Application No. PCT/EP2011/004941 entitled "Methods for tumor treatment and adipogenesis differentiation".
authors: Bioinformatics and Genomics Department, Prince Felipe Research Centre (CIPF), Avda. Autopista del Saler, 16-3 46012 Valencia, Spain.
authors: Jaime
authors: J
authors: Carcel-Trullols
authors: Cristóbal
authors: C
authors: Aguilar-Gallardo
authors: Fernando
authors: F
authors: Garcia-Alcalde
authors: Miguel Angel
authors: MA
authors: Pardo-Cea
authors: Joaquin
authors: J
authors: Dopazo
authors: Ana
authors: A
authors: Conesa
authors: Carlos
authors: C
authors: Simón
keywords: Adipogenic Gene Markers; Cell Transdifferentiation; Clathrin; Clathrin-mediated Endocytosis; Loss of Pigmentation; PPARG; Perilipin 2; Unsaturated Fatty Acids
references: J Virol. 2007 Aug;81(16):8722-9
references: 17522231
references: Cell Tissue Res. 1998 Nov;294(2):309-21
references: 9799447
references: Nature. 2009 Dec 3;462(7273):587-94
references: 19956253
references: Curr Opin Struct Biol. 2000 Apr;10(2):220-8
references: 10753805
references: Mol Cell Biol. 2007 May;27(9):3456-69
references: 17339344
references: Cell Mol Life Sci. 2012 Jun;69(11):1755-71
references: 22113372
references: Nat Rev Mol Cell Biol. 2004 Feb;5(2):121-32
references: 15040445
references: Clin Chem. 1959 Apr;5(2):149-60
references: 13639310
references: Cell. 1991 Aug 23;66(4):663-74
references: 1652368
references: Lipids. 2012 Oct;47(10):973-86
references: 22923370
references: J Lab Clin Med. 1996 May;127(5):470-80
references: 8621984
references: Nat Methods. 2010 Sep;7(9):709-15
references: 20711195
references: PLoS One. 2008 Jan 02;3(1):e1384
references: 18167543
references: J Biol Chem. 2005 Apr 8;280(14):14006-16
references: 15695812
references: Genome Res. 2011 Dec;21(12):2213-23
references: 21903743
references: Blood. 1976 Jan;47(1):133-43
references: 1244908
references: J Cell Biol. 1963 May;17:299-313
references: 13985244
references: Nat Rev Mol Cell Biol. 2007 Oct;8(10):786-97
references: 17878918
references: J Mol Med (Berl). 2002 Dec;80(12):753-69
references: 12483461
references: J Cell Biol. 1997 Jan 13;136(1):81-93
references: 9008705
references: Mol Biol Cell. 1999 May;10(5):1581-94
references: 10233164
references: Nucleic Acids Res. 2010 Jan;38(Database issue):D211-22
references: 19920124
references: J Cell Sci. 1999 Dec;112 ( Pt 24):4793-800
references: 10574726
references: Proc Natl Acad Sci U S A. 2005 Feb 15;102(7):2340-5
references: 15701701
references: Mol Membr Biol. 1999 Jan-Mar;16(1):33-42
references: 10332735
references: Genome Biol. 2010;11(2):R14
references: 20132535
references: J Clin Invest. 1999 Jun;103(11):1489-98
references: 10359558
references: J Cell Biol. 1985 Mar;100(3):965-73
references: 3972906
references: Metabolism. 2007 May;56(5):676-85
references: 17445544
references: Cell. 2010 Aug 6;142(3):375-86
references: 20691899
references: J Virol. 2006 Sep;80(17):8830-3
references: 16912330
references: Nature. 2009 Jun 4;459(7247):708-11
references: 19396158
references: Bioinformatics. 2009 May 1;25(9):1105-11
references: 19289445
references: Stem Cell Rev Rep. 2009 Dec;5(4):319-27
references: 20058196
references: Traffic. 2002 Sep;3(9):678-93
references: 12191019
references: J Lipid Res. 1975 Jul;16(4):269-79
references: 1141768
references: Stem Cell Rev Rep. 2011 Nov;7(4):898-909
references: 21499706
references: J Exp Med. 1947 Aug 31;86(3):215-28
references: 19871672
references: J Lipid Res. 1997 Nov;38(11):2249-63
references: 9392423
references: Am J Physiol. 1995 Jun;268(6 Pt 2):F1177-84
references: 7611458
references: Nature. 2003 Mar 6;422(6927):37-44
references: 12621426
references: J Biol Chem. 1997 Jan 10;272(2):971-6
references: 8995390
references: Nature. 2008 Oct 2;455(7213):627-32
references: 18754011
references: Nature. 2006 Apr 6;440(7085):813-7
references: 16598260
references: Eur J Biochem. 1994 Dec 1;226(2):707-13
references: 8001588
references: Nucleic Acids Res. 2009 Oct;37(18):e123
references: 19620212
references: Am J Physiol Cell Physiol. 2002 Jul;283(1):C235-43
references: 12055092
references: Traffic. 2009 Feb;10(2):218-34
references: 18980610
references: Int J Exp Pathol. 2010 Feb;91(1):24-33
references: 20096071
references: Cell. 1984 Dec;39(2 Pt 1):283-93
references: 6149810