ZEB1 Mediates Bone Marrow Mesenchymal Stem Cell Osteogenic Differentiation Partly via Wnt/β-Catenin Signaling

Zinc finger E-box-binding homebox 1 (ZEB1) is a zinc-finger transcription factor best known for its role in promoting the epithelial-mesenchymal transition, which is also related to osteogenesis. Here, ZEB1 was investigated for its role in the commitment of bone marrow mesenchymal stem cells (BMSCs) to osteoblasts. In vitro, ZEB1 expression decreased following osteogenic differentiation. Furthermore, silencing of ZEB1 in BMSCs promoted osteogenic activity and mineralization. The increase in osteogenic differentiation induced by si-ZEB1 could be partly rescued by the inhibition of Wnt/β-catenin (si-β-catenin). In vivo, knockdown of ZEB1 in BMSCs inhibited the rapid bone loss of ovariectomized (OVX) mice. ZEB1 expression has also been negatively associated with bone mass and bone formation in postmenopausal women. In conclusion, ZEB1 is an essential transcription factor in BMSC differentiation and may serve as a potential anabolic strategy for treating and preventing postmenopausal osteoporosis (PMOP).

Relationship between circulating tumor cells and ZEB1 expression in tumor cells in colorectal cancer.

e15509 Background: Intravasation and circulation of tumor cells involves active invasion of cells with an enhanced migration potential as a result of the epithelial-mesenchymal transition (EMT). The ZEB1 protein is one of the key regulators of this process. Our purpose was to evaluate the association between the amount of circulating tumor cells (CTCs) in the peripheral blood of patients with different stages of colorectal cancer and the expression of ZEB1 by tumor cells. Methods: The study included 299 patients (aged 42-86 years, mean age 64.2±1.7) with stage II-IV CRC T1-4N0-2M0-1; histologically verified G1-G3 adenocarcinoma in all patients. The numbers of CTCs were measured in the peripheral blood before surgery using the Veridex CellSearch system (Janssen). CTCs were registered taking into account morphological characteristics and expression of epithelial cell adhesion markers EpCAM, CD45, cytokeratins 8,18,19. The blood sample was evaluated according to the following criteria: 0 CTCs, 1-3 CTCs, and more than 3 CTCs. Tissues of surgically removed tumors were studied with IHC analysis using rabbit polyclonal anti-ZEB1 antibodies (Biorbyt Ltd.) diluted 1:200 and the Reveal Polyvalent HRP-DAB Detection System. The percentage and the intensity of staining were assessed: 0, 1+ weak, 2+ moderate, 3+ strong. ZEB1 expression was considered positive when staining was detected in more than 10% (cut-off) tumor cells with intensities of 2+ and 3+. Statistical analysis of results was performed in the Statistica 13.0 program (StatSoftInc., USA). Results: From 1 to 402 CTCs were determined in 62.9% cases (in 188 of 299 patients); CTCs were not registered in 37.1% cases (111 of 299). Positive ZEB1 expression was observed in 80.6% (241 of 299 patients), while the negative one was much more rare – 19.4% (58 of 299 patients). The rates of CTC detection significantly increased with the positive ZEB1+ expression, compared to the negative expression (75.1% vs. 12.1%). CTCs >3 were detected in the blood in 39.0% in ZEB1+ tumors, but not in ZEB1- tumors. 1-3 CTCs were observed 3 times more often in ZEB1+ tumors (36.1% vs. 12.1; p≤0.05). Conclusions: Statistically significant association was revealed between the epithelial-mesenchymal transition marker ZEB1 expression by tumor cells and the amount of CTCs in the peripheral blood (p < 0.001).

ZEB1 expression in different stages of colorectal cancer.

e15526 Background: Colorectal cancer (CRC) is among the most common cancers. The leading cause of high mortality is tumor progression developed due to the epithelial to mesenchymal transition (EMT). The ZEB1 protein is one of the critical regulators of this process. In this regard, our study aimed to assess the ZEB1 expression in different stages of colorectal cancer. Methods: This study included samples of 206 patients with stage II-IV CRC aged 42 to 86 years (mean age 64.2±1.7). All patients were divided into three groups: group 1 - patients with T3-4 N0 M0 (stage II) with high-risk factors for recurrence, n = 6; group 2 - patients with T1-4 N1-2 M0 (stage III), n = 88; group 3 - patients with T1-4 N0-2 M1 (stage IV), n = 58. IHC study was performed using polyclonal rabbit antibodies to ZEB1 (Biorbyt Ltd.) diluted 1:200 and a Reveal Polyvalent HRP-DAB Detection System. The staining percentage and intensity were assessed: 0, 1+ weak, 2+ moderate, 3+ strong. The nuclear reaction of the ZEB1 protein was considered positive when staining was detected in more than 10% (cut-off) of tumor cells with intensities of 2+ and 3+. Statistical analysis of the results was carried out using the STATISTICA 13.0 software (StatSoft Inc., USA). Results: A positive nuclear reaction for ZEB1 was detected in 80.6% (166 of 206 patients), while negative in 19.4% (40 of 206 patients). The maximal percentage of patients with positive staining for ZEB1 was among those with stage IV (94.8%), the minimal percentage - stage II (60%). The prevalence of ZEB1+ in patients with stages III and IV significantly increased the risk of tumor progression by 3.5 (95% CI 1.8-8.4) and 12.2 (95% CI 3.4-43.6) times, respectively, compared with stage II patients. No statistical significance was observed in the comparison between patients with stages III and IV (95% CI 0.9-11.7). The percentage of ZEB1+ samples increased in more advanced tumors. The ratio of ZEB1+/ZEB1- tumors in stage II was 1.5, in stage III - 5.8, in stage IV - 18.3 (p < 0.05). Conclusions: The immunohistochemical study revealed the features of ZEB1 expression in different stages of colorectal cancer, which can serve as prognostic factors that determine the disease progression.

Correction to: LncRNA PTAR promotes EMT and invasionmetastasis in serous ovarian cancer by competitively binding miR-101-3p to regulate ZEB1 expression

An amendment to this paper has been published and can be accessed via the original article.