Fzd7/Wnt7b signaling contributes to stemness and chemoresistance in pancreatic cancer.

Mining databases and data obtained from assays on human specimens had shown that Fzd7 is closely associated with Wnt7b, that Fzd7/Wnt7b expression is upregulated in pancreatic cancer tissues compared with normal tissues, and its expression is negatively correlated with survival. Fzd7/Wnt7b knockdown in Capan-2 and Panc-1 cells reduced the proliferative capacity of pancreatic cancer stem cells (PCSCs), reduced drug resistance, decreased the percentage of CD24+ CD44+ subset of cells and the levels of ABCG2, inhibited cell-sphere formation, and reduced gemcitabine (GEM) resistance. In contrast, Fzd7/Wnt7b overexpression increased the percentage of the CD24+ CD44+ subset of cells, and increased the levels of ABCG2 detected in cell spheroids. The gem-resistant cells exhibited higher levels of Fzd7/Wnt7b expression, an increased percentage of CD24+ CD44+ cells, and higher levels of ABCG2 compared with the parental cells. Taken together, Fzd7/Wnt7b knockdown can reduce PDAC cell stemness and chemoresistance by reducing the percentage of CSCs. Mechanistically, Fzd7 binds with Wnt7b and modulates the levels of β-catenin, and they may exert their role via modulation of the canonical Wnt pathway.

Zhang Z ，Xu Y ，Zhao C 《Cancer Medicine》

Regulation of ABCG2 expression by Wnt5a through FZD7 in human pancreatic cancer cells.

Zhang Z ，Gao S ，Xu Y ，Zhao C ... -  《-》

FZD7 accelerates hepatic metastases in pancreatic cancer by strengthening EMT and stemness associated with TGF-β/SMAD3 signaling.

Metastasis of malignant tumors accelerates systemic failure and hastens the deaths of pancreatic cancer patients. During the metastatic process, the physical translocation of cancer cells from the primary lesion to distant organs and is crucial. CSCs properties, such as self-renewal and multiple-direction differentiation capacity are essential for colonization in the microenvironment of distant organs and metastatic lesion formation. It is widely believed that EMT can cause cancer cells to penetrate blood vessels by undergoing phenotypic and cytoskeletal changes, so that they can infiltrate surrounding tissue and disseminate from the primary tumor to the blood circulation, where they are termed circulating tumor cells (CTCs), while CTCs often exhibit stemness properties. Accumulating evidence demonstrates that some EMT-related transcription factors are essential for CSCs self-renewal, so cancer cells that have undergone EMT typically acquire increased stemness properties. Abnormal activation of the WNT signaling pathway can drive a series of gene transcripts to promote EMT in multiple types of cancer, and among different Frizzled receptors of WNT signaling pathway, FZD7 expression is associated with distant organ metastasis, advanced clinical stages, and poor clinical prognosis. Objective of this study is to demonstrate that high FZD7 expression in pancreatic cancer can accelerate hepatic metastases and elucidate the related molecular mechanisms. The expression of Frrizled receptor 7 (FZD7) in pancreatic ductal adenocarcinoma (PDAC) and relating survival rate were analyzed by bioinformatics, histochemistry assay and follow-up study. In vitro, FZD7 expression was silenced by lentiviral vectors carrying short hair RNA (shRNA) or upregulated by overexpression plasmid. Then, Wound-healing and Transwell experiment was used to analyze the abilities of migration and invasion; the levels of epithelial-to-mesenchymal transition (EMT) relating phenotype proteins, stemness relating phenotype proteins, and signaling molecular proteins were measured by Western-blot; cell stemness was evaluated by sphere forming ability of cells in suspension culture and detecting the proportion of CD24+CD44+ cells with flow cytometry. TGF-β1 was used to induce EMT, and observe the effect of shRNA silencing FZD7 on which. High level of FZD7 expression in pancreatic cancer samples was associated with earlier hepatic metastasis. In vitro upregulation FZD7 can enable pancreatic cancer cells to obtain stronger migration and invasion ability and higher mesenchymal phenotype, and vice versa; the proportion of cancer stem cell (CSC) was also positively correlated with the level of FZD7; cells forming spheres in suspension culture showed stronger migration and invasion ability and higher level of mesenchymal phenotype than normal adherent cultured cells; the level of FZD7 was positively correlated with the level of activated β-catenin. Silencing FZD7 expression can attenuate EMT induced by TGF-β1 stimulating, and TGF-β1 stimulating can also upregulate stemness phenotype expression, such as ABCG2, CD24, and CD44 by mediating of FZD7. High FZD7 expression in pancreatic cancer can accelerates hepatic metastases by promoting EMT and strengthening cell stemness, and FZD7 can work through the canonical Wingless-type (WNT) signaling pathway and participate in TGF-β/SMAD3 signaling pathway also.

Zhang Z ，Xu Y 《-》

Targeting Frizzled-7 Decreases Stemness and Chemotherapeutic Resistance in Gastric Cancer Cells by Suppressing Myc Expression.

Cheng Y ，Li L ，Pan S ，Jiang H ，Jin H ... -  《MEDICAL SCIENCE MONITOR》

Cancer stem-like cells enriched in Panc-1 spheres possess increased migration ability and resistance to gemcitabine.

Yin T ，Wei H ，Gou S ，Shi P ，Yang Z ，Zhao G ，Wang C ... -  《-》