Hypoxia-induced Fascin-1 upregulation is regulated by Akt/Rac1 axis and enhances malignant properties of liver cancer cells via mediating actin cytoskeleton rearrangement and Hippo/YAP activation

In solid tumors, hypoxia facilitates malignant progression of cancer cells by triggering epithelial-mesenchymal transition (EMT) and cancer stemness. Fascin-1, an actin-bundling protein, takes part in the formation of many actin-based cellular structures. In the present study, we explored the potential functions of hypoxia-induced upregulation of Fascin-1 in liver cancer. Transcriptome RNA-sequencing was conducted to identify hypoxia-related genes. The potential functions of Fascin-1 were evaluated by western blot, transwell migration and invasion assays, sphere-formation assay, tumor xenograft growth, gelatin zymography analysis, immunofluorescence, cell viability assay, soft agar assay, and flow cytometry. We found that Fascin-1 was upregulated by hypoxia in liver cancer cell lines, elevated in liver cancer patients and correlated with larger tumor size, lymph node metastasis, distant metastasis, and shorter overall survival. Knockdown of Fascin-1 suppressed migration, invasion, EMT, stemness, and tumor xenograft growth of liver cancer cells under both normoxia and hypoxia conditions, while forced Fascin-1 expression showed opposite effects. Moreover, hypoxia-induced upregulation of Fascin-1 was regulated by the Akt/Rac1 signaling, and inhibition of Akt/Rac1 signaling by EHop-016 and MK-2206 restrained migration, invasion, EMT, and stemness of liver cancer cells under hypoxia. Furthermore, Fascin-1 knockdown suppressed MMP-2 and MMP-9 expression, impaired actin cytoskeleton rearrangement, inactivated Hippo/YAP signaling, and increased Sorafenib sensitivity in liver cancer cells. Our study provided a novel insight of Fascin-1 in regulating migration, invasion, EMT, and stemness of liver cancer cells under normoxia and hypoxia conditions.

Astragaloside IV enhanced carboplatin sensitivity in prostate cancer by suppressing AKT/NF-κB signaling pathway

In our study, we explored the effect of AgIV on carboplatin chemotherapy in prostate cancer cell lines in vitro and in vivo. Cell viability assay, colony formation assay, flow cytometry, western blot, immunohistochemistry (IHC), immunofluorescence and tumor xenograft growth assay were conducted. We found that AgIV significantly decreased the half maximal inhibitory concentration (IC50) of carboplatin in prostate cancer cell lines LNCap and PC-3. Moreover, AgIV enhanced the effect of carboplatin in suppressing colony formation and inducing cell apoptosis. A low dose carboplatin treatment upregulated N-cadherin and Vimentin expression and downregulated E-cadherin expression, but this effect was abolished by combining with AgIV. Carboplatin treatment increased the levels of p-AKT and p-p65 and decreased p-IκBα, but AgIV treatment suppressed this. In addition, AgIV synergized with carboplatin to suppress tumor xenograft growth of PC-3 cells, and decreased pAKT and p-p65 levels in vivo. In summary, our results suggested that AgIV enhanced carboplatin sensitivity in prostate cancer cell lines by suppressing AKT/NF-кB signaling, thus suppressed EMT induced by carboplatin. Our findings provided a new mechanism for AgIV in overcoming drug resistance of platinum-based chemotherapy, and suggested a potential combination therapy of AgIV and carboplatin in prostate cancer.

Circular RNA CDR1as Exerts Oncogenic Properties Partially through Regulating MicroRNA 641 in Cholangiocarcinoma

ABSTRACT It has been found that the circular RNA (circRNA) CDR1as is upregulated in cholangiocarcinoma (CCA) tissues. In this study, we tried to explore the roles of CDR1as in CCA. CDR1as was overexpressed or knocked down in human CCA cells to assess the effects of CDR1as on cell behaviors and tumor xenograft growth. In vitro, the CDR1as level was significantly increased in CCA cell lines. The results showed that CDR1as promoted the cell proliferation, migration, invasion, and activation of the AKT3/mTOR pathway in CCA cells. Moreover, miR-641, a predicted target microRNA (miRNA) of CDR1as, could partially reverse the effects of CDR1as on cell behaviors in CCA cells. Furthermore, CDR1as improved tumor xenograft growth, and it could be attenuated by miR-641 in vivo. Additionally, CDR1as expression was inversely correlated with miR-641 in CCA cells, and miR-641 could directly bind with CDR1as and its target genes, the AKT3 and mTOR genes. Mechanistically, CDR1as could bind with miR-641 and accelerate miR-641 degradation, which possibly leads to the upregulation of the relative mRNA levels of AKT3 and mTOR in RBE cells. In conclusion, our findings indicated that CDR1as might exert oncogenic properties, at least partially, by regulating miR-641 in CCA. CDR1as and miR-641 could be considered therapeutic targets for CCA.

Cancer-derived small extracellular vesicles promote angiogenesis by heparin-bound, bevacizumab-insensitive VEGF, independent of vesicle uptake

Cancer-derived small extracellular vesicles (sEVs) induce stromal cells to become permissive for tumor growth. However, it is unclear whether this induction solely occurs through transfer of vesicular cargo into recipient cells. Here we show that cancer-derived sEVs can stimulate endothelial cell migration and tube formation independently of uptake. These responses were mediated by the 189 amino acid isoform of vascular endothelial growth factor (VEGF) on the surface of sEVs. Unlike other common VEGF isoforms, VEGF189 preferentially localized to sEVs through its high affinity for heparin. Interaction of VEGF189 with the surface of sEVs profoundly increased ligand half-life and reduced its recognition by the therapeutic VEGF antibody bevacizumab. sEV-associated VEGF (sEV-VEGF) stimulated tumor xenograft growth but was not neutralized by bevacizumab. Furthermore, high levels of sEV-VEGF were associated with disease progression in bevacizumab-treated cancer patients, raising the possibility that resistance to bevacizumab might stem in part from elevated levels of sEV-VEGF.

Phospho-valproic acid (MDC-1112) reduces pancreatic cancer growth in patient-derived tumor xenografts and KPC mice: enhanced efficacy when combined with gemcitabine

New chemotherapeutic agents are needed for pancreatic cancer (PC). We have previously shown that phospho-valproic acid (MDC-1112) is effective in cell-line xenografts of PC. Here, we explored whether MDC-1112 is effective in additional clinically relevant animal models of PC and whether MDC-1112 enhances the anticancer effect of clinically used chemotherapeutic agents. MDC-1112 alone strongly reduced patient-derived pancreatic tumor xenograft growth, and extended survival of LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) mice. In both models, MDC-1112 inhibited STAT3 activation and its downstream signals, including Bcl-xL and cyclin D1. In human PC cell lines, P-V enhanced the growth inhibitory effect of gemcitabine (GEM), Abraxane and 5-FU, but not that of irinotecan. Normal human pancreatic epithelial cells were more resistant to the cytotoxic effects of MDC-1112/GEM combination. Furthermore, MDC-1112 enhanced GEM’s effect on colony formation, apoptosis, cell migration, and cell invasion. In vivo, MDC-1112 and GEM, given alone, reduced patient-derived pancreatic tumor xenograft growth by 58% and 87%, respectively; whereas MDC-1112/GEM combination reduced tumor growth by 94%, inducing tumor stasis. In conclusion, MDC-1112 should be further explored as a potential agent to be used in combination with GEM for treating PC.