ZEB1-responsive genes in non-small cell lung cancer

Abstract

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 8 genes selected for validation, 7 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, overexpression 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.

miR-154 inhibits migration and invasion of human non-small cell lung cancer by targeting ZEB2

“…including NSCLC (23,33). Growing evidence suggests that ZEB2 could induce EMT through suppressing E-cadherin expression or inducing vimentin expression, thus facilitating the metastasis of cancer cells (24,25,34,35).…”

Different thresholds of ZEB1 are required for Ras-mediated tumour initiation and metastasis

“…We also examined the tumour stroma where ZEB1 has been shown previously to be expressed in some tumours 12,23 . Interestingly, we found that the same ZEB1-high, PTEN-low proliferating pattern seen in the K-Ras pathway mutant tumour cells was recapitulated in the tumour-associated stromal fibroblasts (Supplementary Figs 2-5).…”

MicroRNA‑335 is downregulated in papillary thyroid cancer and suppresses cancer cell growth, migration and invasion by directly targeting ZEB2

“…To determine whether miR-335 directly targets ZEB2, a dual-luciferase reporter assay was performed; it was revealed that miR-335 significantly decreased the luciferase activity ZEB2, a member of the zinc finger family, functions as a transcriptional repressor of E-cadherin (37). ZEB2 has been identified as upregulated in various types of human cancer, including breast, gastric, head and neck, hepatocellular, ovarian and non-small cell lung carcinoma, and glioma (38)(39)(40)(41)(42)(43)(44). ZEB2 was previously identified as upregulated in PTC cell lines compared with normal thyroid cancer cells (45).…”