VX-509 attenuates the stemness characteristics of colorectal cancer stem-like cells by regulating the epithelial-mesenchymal transition through Nodal/Smad2/3 signaling

BACKGROUND

Colorectal cancer stem cells (CCSCs) are heterogeneous cells that can self-renew and undergo multidirectional differentiation in colorectal cancer (CRC) patients. CCSCs are generally accepted to be important sources of CRC and are responsible for the progression, metastasis, and therapeutic resistance of CRC. Therefore, targeting this specific subpopulation has been recognized as a promising strategy for overcoming CRC.

AIM

To investigate the effect of VX-509 on CCSCs and elucidate the underlying mechanism.

METHODS

CCSCs were enriched from CRC cell lines by in conditioned serum-free medium. Western blot, Aldefluor, transwell and tumorigenesis assays were performed to verify the phenotypic characteristics of the CCSCs. The anticancer efficacy of VX-509 was assessed in HCT116 CCSCs and HT29 CCSCs by performing cell viability analysis, colony formation, sphere formation, flow cytometry, and western blotting assessments in vitro and tumor growth, immunohistochemistry and immunofluorescence assessments in vivo.

RESULTS

Compared with parental cells, sphere cells derived from HCT116 and HT29 cells presented increased expression of stem cell transcription factors and stem cell markers and were more potent at promoting migration and tumorigenesis, demonstrating that the CRC sphere cells displayed CSC features. VX-509 inhibited the tumor malignant biological behavior of CRC-stem-like cells, as indicated by their proliferation, migration and clonality in vitro, and suppressed the tumor of CCSC-derived xenograft tumors in vivo. Besides, VX-509 suppressed the CSC characteristics of CRC-stem-like cells and inhibited the progression of epithelial-mesenchymal transition (EMT) signaling in vitro. Nodal was identified as the regulatory factor of VX-509 on CRC stem-like cells through analyses of differentially expressed genes and CSC-related database information. VX-509 markedly downregulated the expression of Nodal and its downstream phosphorylated Smad2/3 to inhibit EMT progression. Moreover, VX-509 reversed the dedifferentiation of CCSCs and inhibited the progression of EMT induced by Nodal overexpression.

CONCLUSION

VX-509 prevents the EMT process in CCSCs by inhibiting the transcription and protein expression of Nodal, and inhibits the dedifferentiated self-renewal of CCSCs.

Topical VX-509 attenuates psoriatic inflammation through the STAT3/FABP5 pathway in keratinocytes

BACKGROUND

Psoriasis is a chronic inflammatory disease, with lesions mainly manifesting as scaly erythematous plaques. The mild or moderate of psoriasis is the main type of patients in hospital, and topical application remains the preferred treatment option for psoriasis therapy, therefore, the development of novel topical agents has an essential role in psoriasis therapy.

OBJECTIVE

To identify potential drugs for psoriasis topical treatment.

METHODS

We performed drug screening by Imiquimod (IMQ)-induced psoriatic like inflammation in mouse model, followed mouse epidermis by RNA-seq to find the key molecules affecting the drug. The qRT-PCR, WB were performed to test mRNA and protein expression, and Chip assay had been conducted to examine Stat3 bound to promoter of FABP5.

RESULTS

In this study, we identified VX-509, which topical application significantly attenuated IMQ-induced psoriatic like inflammation in mouse model. And then, we verified Epidermal Fatty acid binding protein (E-FABP/FABP5) was significantly decreased in VX-509 treated mouse epidermis by RNA-seq. FABP5 is a key molecule in lipid metabolism, administration of FABP5 inhibitor or knock down of FABP5 expression remarkably abrogated psoriatic inflammation as well as lipid metabolism. Mechanistically, our finding showed that VX-509 blocked IL-22 induced signaling pathway, particular in activation of Stat3. Furthermore, we identified Stat3 is a transcriptional factor associated with FABP5 promoters and VX-509 treatment remarkably attenuated IL-22-induced FABP5 expression through Stat3 in KCs.

CONCLUSIONS

This study demonstrated administration of VX-509 is a potential promising topical drug for treatment of psoriasis, FABP5 is a critical targeted molecule in psoriasis therapy.