title: Cortactin modulates RhoA activation and expression of Cip/Kip cyclin-dependent kinase inhibitors to promote cell cycle progression in 11q13-amplified head and neck squamous cell carcinoma cells.
abstract: The cortactin oncoprotein is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC), often due to amplification of the encoding gene (CTTN). While cortactin overexpression enhances invasive potential, recent research indicates that it also promotes cell proliferation, but how cortactin regulates the cell cycle machinery is unclear. In this article we report that stable short hairpin RNA-mediated cortactin knockdown in the 11q13-amplified cell line FaDu led to increased expression of the Cip/Kip cyclin-dependent kinase inhibitors (CDKIs) p21(WAF1/Cip1), p27(Kip1), and p57(Kip2) and inhibition of S-phase entry. These effects were associated with increased binding of p21(WAF1/Cip1) and p27(Kip1) to cyclin D1- and E1-containing complexes and decreased retinoblastoma protein phosphorylation. Cortactin regulated expression of p21(WAF1/Cip1) and p27(Kip1) at the transcriptional and posttranscriptional levels, respectively. The direct roles of p21(WAF1/Cip1), p27(Kip1), and p57(Kip2) downstream of cortactin were confirmed by the transient knockdown of each CDKI by specific small interfering RNAs, which led to partial rescue of cell cycle progression. Interestingly, FaDu cells with reduced cortactin levels also exhibited a significant diminution in RhoA expression and activity, together with decreased expression of Skp2, a critical component of the SCF ubiquitin ligase that targets p27(Kip1) and p57(Kip2) for degradation. Transient knockdown of RhoA in FaDu cells decreased expression of Skp2, enhanced the level of Cip/Kip CDKIs, and attenuated S-phase entry. These findings identify a novel mechanism for regulation of proliferation in 11q13-amplified HNSCC cells, in which overexpressed cortactin acts via RhoA to decrease expression of Cip/Kip CDKIs, and highlight Skp2 as a downstream effector for RhoA in this process.
authors.affiliation: Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW, Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Croucher
authors.forename: Danny
authors.initials: D
authors.lastname: Rickwood
authors.forename: Carole M
authors.initials: CM
authors.lastname: Tactacan
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Musgrove
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Daly
mesh_terms: D001483:Base Sequence; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D002453:Cell Cycle / Q000235:genetics* / Q000502:physiology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D051356:Cortactin / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000502:physiology*; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000235:genetics* / Q000502:physiology*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000502:physiology; D050760:Cyclin-Dependent Kinase Inhibitor p27; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D005784:Gene Amplification; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics; D020742:rhoA GTP-Binding Protein / Q000235:genetics* / Q000502:physiology*
chemical_list: C493956:CDKN1A protein, human; C436291:CDKN1B protein, human; C493964:CDKN1C protein, human; C495868:CTTN protein, human; D051356:Cortactin; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050761:Cyclin-Dependent Kinase Inhibitor p57; D017931:DNA Primers; D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; C066737:RHOA protein, human; D050760:Cyclin-Dependent Kinase Inhibitor p27; D020742:rhoA GTP-Binding Protein
references.citation: Mol Cell Biol. 2000 Apr;20(7):2581-91
references.pmid: 10713180
references.citation: Oncogene. 2009 Jan 22;28(3):431-44
references.pmid: 18931703
references.citation: Biochem J. 2007 Dec 15;408(3):297-315
references.pmid: 17850214
references.citation: Blood. 2002 Dec 15;100(13):4462-9
references.pmid: 12453877
references.citation: Oncogene. 1999 Aug 5;18(31):4440-9
references.pmid: 10442635
references.citation: J Biol Chem. 2006 Oct 6;281(40):30081-93
references.pmid: 16905744
references.citation: Oncogene. 1997 Sep 25;15(13):1617-23
references.pmid: 9380415
references.citation: Eur J Cell Biol. 2008 Sep;87(8-9):581-90
references.pmid: 18342393
references.citation: Mol Biol Cell. 2002 Mar;13(3):902-14
references.pmid: 11907271
references.citation: Clin Cancer Res. 2000 Aug;6(8):3177-82
references.pmid: 10955801
references.citation: Breast Cancer Res Treat. 2004 Mar;84(1):33-42
references.pmid: 14999152
references.citation: Br J Cancer. 2008 Mar 11;98(5):956-64
references.pmid: 18268492
references.citation: Cancer Res. 2006 Dec 15;66(24):11690-9
references.pmid: 17178864
references.citation: Breast Cancer Res Treat. 2003 Apr;78(3):323-35
references.pmid: 12755491
references.citation: Mol Biol Cell. 2009 Jul;20(14):3209-23
references.pmid: 19458196
references.citation: J Biol Chem. 2004 Jun 18;279(25):26323-30
references.pmid: 15096506
references.citation: DNA Repair (Amst). 2007 Jul 1;6(7):953-66
references.pmid: 17531546
references.citation: Nat Cell Biol. 2004 Dec;6(12):1229-35
references.pmid: 15531880
references.citation: Mol Cancer Res. 2009 Apr;7(4):570-80
references.pmid: 19372585
references.citation: Curr Biol. 2005 Jul 26;15(14):1276-85
references.pmid: 16051170
references.citation: Oncogene. 1998 Jun 25;16(25):3227-32
references.pmid: 9681820
references.citation: J Biol Chem. 2001 Dec 14;276(50):47675-83
references.pmid: 11590147
references.citation: Oral Oncol. 2009 Dec;45(12):1032-6
references.pmid: 19666237
references.citation: Gene. 1995 Jun 14;159(1):83-96
references.pmid: 7607576
references.citation: Nature. 1998 Jul 16;394(6690):295-9
references.pmid: 9685162
references.citation: J Biol Chem. 1998 Oct 2;273(40):25770-6
references.pmid: 9748248
references.citation: J Cell Biochem. 2006 Feb 1;97(2):261-74
references.pmid: 16267837
references.citation: Curr Biol. 1999 Feb 11;9(3):136-45
references.pmid: 10021386
references.citation: Br J Cancer. 2008 Mar 11;98(5):950-5
references.pmid: 18268491
references.citation: Nat Cell Biol. 1999 Aug;1(4):207-14
references.pmid: 10559918
references.citation: Proc Natl Acad Sci U S A. 2003 Sep 2;100(18):10231-6
references.pmid: 12925736
references.citation: Expert Rev Mol Med. 2008 Jul 01;10:e19
references.pmid: 18590585
references.citation: Cancer Res. 1997 Oct 1;57(19):4360-7
references.pmid: 9331099
references.citation: EMBO J. 2001 Feb 15;20(4):755-66
references.pmid: 11179220
references.citation: J Biol Chem. 2002 Mar 8;277(10):8517-23
references.pmid: 11751903
references.citation: Biochem Biophys Res Commun. 1977 Jul 11;77(1):403-8
references.pmid: 883985
references.citation: Nat Cell Biol. 1999 Aug;1(4):193-9
references.pmid: 10559916
references.citation: Mol Cell Biol. 2006 Jun;26(12):4612-27
references.pmid: 16738326
references.citation: Cancer Res. 2005 Apr 15;65(8):3273-80
references.pmid: 15833860
references.citation: EMBO J. 1996 Dec 16;15(24):7060-9
references.pmid: 9003781
references.citation: Cancer Res. 2006 Aug 15;66(16):8017-25
references.pmid: 16912177
references.citation: Mol Cell Biol. 2002 Nov;22(21):7581-92
references.pmid: 12370305
references.citation: Proc Natl Acad Sci U S A. 2007 Jul 17;104(29):11933-8
references.pmid: 17606906
references.citation: J Cell Sci. 2007 Oct 1;120(Pt 19):3475-87
references.pmid: 17855386
references.citation: Genes Dev. 1997 Apr 1;11(7):847-62
references.pmid: 9106657
references.citation: Cancer Lett. 2008 Jul 8;265(2):157-66
references.pmid: 18406052
references.citation: Cancer Res. 2007 May 1;67(9):4227-35
references.pmid: 17483334
references.citation: J Biol Chem. 1997 Dec 26;272(52):32966-71
references.pmid: 9407076
references.citation: J Cell Sci. 2008 Apr 15;121(Pt 8):1334-43
references.pmid: 18388321
references.citation: Cancer Res. 2007 Oct 1;67(19):9304-14
references.pmid: 17909038
references.citation: J Pathol. 2009 Mar;217(4):516-23
references.pmid: 18991334
references.citation: EMBO J. 1999 Mar 15;18(6):1571-83
references.pmid: 10075928
references.citation: J Biol Chem. 2003 Nov 14;278(46):45903-14
references.pmid: 12944407
references.citation: Anticancer Res. 1993 Sep-Oct;13(5A):1405-13
references.pmid: 8239512
references.citation: Biochem J. 2004 Aug 15;382(Pt 1):13-25
references.pmid: 15186216
references.citation: Curr Biol. 1999 Jun 17;9(12):661-4
references.pmid: 10375532
references.citation: Mol Cancer Res. 2009 Dec;7(12):1902-19
references.pmid: 19934273