ZEB1-responsive genes in non-small cell lung cancer.
The epithelial to mesenchymal transition (EMT) is a developmental process enabling epithelial cells to gain a migratory mesenchymal phenotype. In cancer, this process contributes to metastases; however the regulatory signals and mechanistic details are not fully elucidated. Here, we sought to identify the subset of genes regulated in lung cancer by ZEB1, an E-box transcriptional repressor known to induce EMT. Using an Affymetrix-based expression database of 38 non-small cell lung cancer (NSCLC) cell lines, we identified 324 genes that correlated negatively with ZEB1 and 142 that were positively correlated. A mesenchymal gene pattern (low E-cadherin, high Vimentin or N-cadherin) was significantly associated with ZEB1 and ZEB2, but not with Snail, Slug, Twist1 or Twist2. Among eight genes selected for validation, seven were confirmed to correlate with ZEB1 by quantitative real-time RT-PCR in a series of 22 NSCLC cell lines, either negatively (CDS1, EpCAM, ESRP1, ESRP2, ST14) or positively (FGFR1, Vimentin). In addition, over-expression or knockdown of ZEB1 led to corresponding changes in gene expression, demonstrating that these genes are also regulated by ZEB1, either directly or indirectly. Of note, the combined knockdown of ZEB1 and ZEB2 led to apparent synergistic responses in gene expression. Furthermore, these responses were not restricted to artificial settings, since most genes were similarly regulated during a physiologic induction of EMT by TGF-β plus EGF. Finally, the absence of ST14 (matriptase) was linked to ZEB1 positivity in lung cancer tissue microarrays, implying that the regulation observed in vitro applies to the human disease. In summary, this study identifies a new set of ZEB-regulated genes in human lung cancer cells and supports the hypothesis that ZEB1 and ZEB2 are key regulators of the EMT process in this disease.
Gemmill
Robert M
RM
Division of Hematology-Oncology, Department of Medicine and the Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA.
Roche
Joëlle
J
Potiron
Vincent A
VA
Nasarre
Patrick
P
Mitas
Michael
M
Coldren
Chris D
CD
Helfrich
Barbara A
BA
Garrett-Mayer
Elizabeth
E
Bunn
Paul A
PA
Drabkin
Harry A
HA
D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000473:pathology*; D045744:Cell Line, Tumor; D058750:Epithelial-Mesenchymal Transition; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology*; D012097:Repressor Proteins / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000032:analysis; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1
D015820:Cadherins; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C486307:ZEB1 protein, human; C492363:ZEB2 protein, human; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1; D012697:Serine Endopeptidases; C485596:ST14 protein, human