Focal adhesion assembly in myofibroblasts fosters a microenvironment that promotes tumor growth.
Cells within the tumor microenvironment influence tumor growth through multiple mechanisms. Pericytes such as hepatic stellate cells are an important cell within the tumor microenvironment; their transformation into highly motile myofibroblasts leads to angiogenesis, stromal cell recruitment, matrix deposition, and ensuing tumor growth. Thus, a better understanding of mechanisms that regulate motility of pericytes is required. Focal adhesions (FAs) form a physical link between the extracellular environment and the actin cytoskeleton, a requisite step for cell motility. FAs contain a collection of proteins including the Ena/VASP family member, vasodilator-stimulated phosphoprotein (VASP); however, a role for VASP in FA development has been elusive. Using a comprehensive siRNA knockdown approach and a variety of VASP mutants coupled with complementary cell imaging methodologies, we demonstrate a requirement of VASP for optimal development of FAs and cell spreading in LX2 liver myofibroblasts, which express high levels of endogenous VASP. Rac1, a binding partner of VASP, acts in tandem with VASP to regulate FAs. In vivo, perturbation of Ena/VASP function in tumor myofibroblast precursor cells significantly reduces pericyte recruitment to tumor vasculature, myofibroblastic transformation, tumor angiogenesis, and tumor growth, providing in vivo pathobiologic relevance to these findings. Taken together, our results identify Ena/VASP as a significant modifier of tumor growth through regulation of FA dynamics and ensuing pericyte/myofibroblast function within the tumor microenvironment.
Kang
Ningling
N
Mayo Clinic, Rochester, Minnesota 55905, USA. kang.ningling@mayo.edu
Yaqoob
Usman
U
Geng
Zhimin
Z
Bloch
Kenneth
K
Liu
Chunsheng
C
Gomez
Timothy
T
Billadeau
Daniel
D
Shah
Vijay
V
D000818:Animals; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000637:transplantation; D022001:Focal Adhesions / Q000378:metabolism / Q000473:pathology*; D055166:Hepatic Stellate Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D047468:Immunoprecipitation; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology*; D009374:Neoplasms, Experimental / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D059016:Tumor Microenvironment; D016596:Vinculin / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D000098662:Vasodilator-Stimulated Phosphoprotein
D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D000098662:Vasodilator-Stimulated Phosphoprotein; D016596:Vinculin; D020830:rac1 GTP-Binding Protein
Virchows Arch. 1997 Mar;430(3):195-207
9099976
Int J Oncol. 2009 Jan;34(1):53-60
19082477
J Cell Biol. 1988 Nov;107(5):1863-71
2972732
Cancer Sci. 2009 Apr;100(4):646-53
19175606
Histochem Cell Biol. 2006 May;125(5):457-74
16267652
Cancer Res. 2008 Apr 1;68(7):2085-93
18381413
Annu Rev Cell Dev Biol. 2003;19:541-64
14570581
Oncogene. 2009 Dec 10;28(49):4326-43
19826415
EMBO J. 1995 Jan 3;14(1):19-27
7828592
Trends Cell Biol. 2002 Aug;12(8):382-9
12191915
Arterioscler Thromb Vasc Biol. 2009 Apr;29(4):562-70
19150878
Science. 2001 Nov 23;294(5547):1708-12
11721053
Curr Biol. 1998 Apr 23;8(9):479-88
9560340
Nat Rev Mol Cell Biol. 2005 Jan;6(1):56-68
15688067
J Biol Chem. 2000 Aug 18;275(33):25723-32
10851246
FEBS Lett. 1996 Dec 9;399(1-2):103-7
8980130
Gut. 2005 Jan;54(1):142-51
15591520
J Cell Biol. 2003 Nov 10;163(3):583-95
14610060
Lymphat Res Biol. 2004;2(2):96-100
15615491
Am J Pathol. 2008 Oct;173(4):1002-12
18755846
PLoS One. 2009;4(3):e4765
19277120
Am J Physiol Cell Physiol. 2008 Jan;294(1):C178-88
17989211
Nat Rev Cancer. 2006 May;6(5):392-401
16572188
J Biol Chem. 2001 Apr 27;276(17):14249-56
11120737
J Cell Biol. 2006 Feb 27;172(5):771-82
16505170
Hepatology. 2001 Jul;34(1):82-8
11431737
Neuron. 2007 Nov 8;56(3):441-55
17988629
Circulation. 2002 Jan 1;105(1):112-7
11772885
Hepatology. 2003 Mar;37(3):674-85
12601365
Oncol Rep. 2008 Apr;19(4):1015-20
18357390
J Biol Chem. 2006 Jul 7;281(27):18652-9
16698790
J Biol Chem. 2007 Jul 27;282(30):22089-101
17513865
Trends Cell Biol. 2003 Jul;13(7):386-92
12837609
Biochem J. 1996 Sep 15;318 ( Pt 3):753-7
8836115
EMBO J. 2003 Jun 16;22(12):3050-61
12805219
Dev Cell. 2008 Dec;15(6):813-28
19081071
J Biol Chem. 1999 Aug 13;274(33):23549-57
10438535
Am J Clin Pathol. 2000 Apr;113(4):555-62
10761458
J Cell Sci. 1984 Oct;71:51-9
6084007
Cell. 1996 Oct 18;87(2):227-39
8861907
J Clin Invest. 2003 Oct;112(8):1142-51
14561699
Nat Clin Pract Gastroenterol Hepatol. 2004 Dec;1(2):98-105
16265071
J Cell Sci. 2007 Feb 1;120(Pt 3):492-501
17251380
Oncol Rep. 2008 Oct;20(4):929-39
18813837
EMBO J. 1997 Sep 1;16(17):5433-44
9312002
Ann Surg Oncol. 2009 Sep;16(9):2645-53
19588204
EMBO J. 1995 Apr 18;14(8):1583-9
7737110
Gastroenterology. 2008 Aug;135(2):671-9
18570897
Cancer Microenviron. 2008 Dec;1(1):113-29
19308690
Am J Physiol Cell Physiol. 2009 Mar;296(3):C453-62
19118163
Am J Pathol. 2005 Jun;166(6):1861-70
15920170
Cell. 2000 Jun 23;101(7):717-28
10892743
Oncol Rep. 2009 Feb;21(2):357-62
19148508
J Cell Physiol. 2009 Aug;220(2):357-66
19347869