Focal adhesion kinase depletion reduces human hepatocellular carcinoma growth by repressing enhancer of zeste homolog 2.
Hepatocellular carcinoma (HCC) is the most common type of liver cancer in humans. The focal adhesion tyrosine kinase (FAK) is often over-expressed in human HCC and FAK inhibition may reduce HCC cell invasiveness. However, the anti-oncogenic effect of FAK knockdown in HCC cells remains to be clarified. We found that FAK depletion in HCC cells reduced in vitro and in vivo tumorigenicity, by inducing G2/M arrest and apoptosis, decreasing anchorage-independent growth, and modulating the expression of several cancer-related genes. Among these genes, we showed that FAK silencing decreased transcription and nuclear localization of enhancer of zeste homolog 2 (EZH2) and its tri-methylation activity on lysine 27 of histone H3 (H3K27me3). Accordingly, FAK, EZH2 and H3K27me3 were concomitantly upregulated in human HCCs compared to non-tumor livers. In vitro experiments demonstrated that FAK affected EZH2 expression and function by modulating, at least in part, p53 and E2F2/3 transcriptional activity. Moreover, FAK silencing downregulated both EZH2 binding and histone H3K27me3 levels at the promoter of its target gene NOTCH2. Finally, we found that pharmacological inhibition of FAK activity resembled these effects although milder. In summary, we demonstrate that FAK depletion reduces HCC cell growth by affecting cancer-promoting genes including the pro-oncogene EZH2. Furthermore, we unveil a novel unprecedented FAK/EZH2 crosstalk in HCC cells, thus identifying a targetable network paving the way for new anticancer therapies.
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Daniela
D
Gnani
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Ilaria
I
Romito
UOSD SAFU, Regina Elena National Cancer Institute, Rome, Italy.
Simona
S
Artuso
Fondazione Bruno Kessler, Trento, Italy.
Marco
M
Chierici
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Cristiano
C
De Stefanis
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Nadia
N
Panera
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Annalisa
A
Crudele
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Sara
S
Ceccarelli
Department of Oncohematology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Elena
E
Carcarino
Microscopy Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Valentina
V
D'Oria
UOSD SAFU, Regina Elena National Cancer Institute, Rome, Italy.
Manuela
M
Porru
FACs Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Ezio
E
Giorda
Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
Karin
K
Ferrari
Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome, Italy.
Luca
L
Miele
Gastroenterology, Department of Internal Medicine, University of Modena and Reggio Emilia, Modena, Italy.
Erica
0000-0001-6388-7022
E
Villa
Institute of Molecular Biology and Pathology, National Research Council, Rome, Italy.
Clara
C
Balsano
Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
Diego
0000-0002-9879-6486
D
Pasini
Fondazione Bruno Kessler, Trento, Italy.
Cesare
C
Furlanello
Department of Oncohematology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.|University of Pavia, Pavia, Italy.
Franco
F
Locatelli
Hepato-Metabolic Disease Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Valerio
V
Nobili
Department of Oncohematology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Rossella
0000-0002-9408-7711
R
Rota
UOSD SAFU, Regina Elena National Cancer Institute, Rome, Italy.
Carlo
C
Leonetti
Liver Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Anna
0000-0001-7241-6329
A
Alisi
D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D050703:E2F2 Transcription Factor / Q000235:genetics / Q000378:metabolism; D050699:E2F3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000235:genetics* / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D059565:G2 Phase Cell Cycle Checkpoints; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051883:Receptor, Notch2 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
D000631:Aminopyridines; D050703:E2F2 Transcription Factor; D050699:E2F3 Transcription Factor; C484940:E2f2 protein, mouse; C490840:E2f3 protein, mouse; D006657:Histones; C497765:Notch2 protein, mouse; C559284:PND 1186; D034741:RNA, Small Interfering; D051883:Receptor, Notch2; D016159:Tumor Suppressor Protein p53; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D051417:Focal Adhesion Kinase 1; C496051:Ptk2 protein, mouse