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Human non‑small cell lung cancer (NSCLC) is associated with an extremely poor prognosis especially for the 40% of patients who develop brain metastasis, and few treatment strategies exist. Cucurbitacin E (CuE), an oxygenated tetracyclic triterpenoid isolated from plants particularly of the family Cucurbitaceae, has shown anti‑tumorigenic properties in several types of cancer, yet the mechanism remains unclear. Yes‑associated protein (YAP), a main mediator of the Hippo signaling pathway, promotes tumorigenesis, drug resistance and metastasis in human NSCLC. The present study was designed to ascertain whether CuE inhibits YAP and its downstream gene expression in the human NSCLC cell lines H2030‑BrM3 (K‑rasG12C mutation) and PC9‑BrM3 (EGFRΔexon19 mutation), which have high potential for brain metastasis. The efficacy of CuE in suppressing brain metastasis of H2030‑BrM3 cells in a murine model was also investigated. It was found that after CuE treatment in H2030‑BrM3 and PC9‑BrM3 cells, YAP protein expression was decreased, and YAP signaling GTIIC reporter activity and expression of the downstream genes CTGF and CYR61 were significantly (P

Objective To explore regulation mechanism of carboxyamidotriazole-orotate (CTO) on oncogenic phenotype of mouse glioma-associated macrophages. Methods Bone marrow-derived macrophages(BMDMs) or RAW264.7 macrophages (tumor associated macrophages,TAMs) were prepared by super-culture of mouse glioma GL261 cells. The mRNA of TAMs oncogenic mediators was detected by qPCR. The oxygen consumption rate (OCR) of TAMs was measured by Seahorse bioenergy method. The protein level of hypoxia-inducible factor-1 α(HIF-1α), hypoxia-inducible factor-2 α (HIF-2α) and peroxisome proliferator-activated receptor (PPAR) co-activator factor-1 β (PGC-1β) in TAMs was detected by Western blot. Results CTO decreased M1-related mediators such as IL-1β, IL-6 and TNF-α(P＜0.001) and M2-related mediators such as IL-10, ARG-1 and TGF-β1(P＜0.001) in TAMs. CTO significantly down-regulated OCR in TAMs (P＜0.01); The protein level of HIF-1α and of HIF-2α in TAMs was down-regulated by CTO(P＜0.01),which was contrary to the effect of carboxycyanide-4-trifluormethoxyphenylhydrazone (FCCP),which in turn promoted mitochondrial oxygen consumption. CTO significantly reduced PGC-1β protein in TAMs (P＜0.001),an effect consistent with rotenone(RTN), a mitochondrial respiratory chain inhibitor. Conclusions A decreased oxidative phosphorylation down-regulates the expression of PGC-1β and destabilizes HIF-1α and HIF-2α, thus affects the production of several M1 and M2 phenotypes of carcinogenic mediators in TAMs, which may be a potential mechanism through which CTO improves the chemotherapy efficacy of glioblastoma.

Objective To investigate the effects of carboxyamidotriazole-orotate (CTO) on proliferation, apoptosis and metabolism of human pancreatic cancer gemcitabine-resistant cell line (ASPC-1-GEM, AG cells). Methods Cell viability was detected by sulforhodamine B(SRB); apoptosis was detected by annexin V/PI staining and flow cytometry; cell division rate was examined by CFSE microscopy and flow cytometry; The oxygen consumption rate (OCR) was detected by Seahorse bio-energy assay; intracellular NAD+ and NADH contents were detected with MTT and NAD+/NADH ratio was calculated. Autophagy-related protein expression was detected by Western blot. Results Comparing with the control group, the living AG cells were significantly reduced and the proportion of apoptotic cells was increased in CTO-treated group. The drug effect was time-dose dependent. The fluorescence intensity of CFSE staining of AG cells was significantly increased in the 20 μmol/L CTO group (P＜0.05); Compared with the control group, intracellular nicotinamide adenine dinucleotidehydrogen(NADH) content was increased after incubation with different concentrations of CTO treatment(P＜0.05 or P＜0.01) and no significant change in the content of nicotinamide adenine dinucleotide (NAD+) NDA+/NADH ratio was decreased(P＜0.01). The OCR in AG cells was significantly reduced and the expression of autophagy-related proteins was significantly inhibited in the CTO-treated group (P＜0.05). Conclusions CTO inhibits the proliferation of gemcitabine-resistant pancreatic cancer cells by inducing apoptosis, impairing mitochondrial respiration, and down-regulating the expression of autophagy-related proteins in AG cells.

Although tumour PD-L1 (CD274) expression had been used as a predictive biomarker in checkpoint immunotherapy targeting the PD1/PD-L1 axis in various cancers, the regulation of PD-L1 (CD274) expression is unclear. Yes-associated protein (YAP), an important oncogenic protein in Hippo signalling pathway, reportedly promotes cancer development. We investigated whether inhibition of YAP down-regulates PD-L1 (CD274) in human malignant pleural mesothelioma (MPM). Western blotting showed that 2 human MPM cell lines (H2052 and 211H) had increased PD-L1 protein expression compared to H290, MS-1 and H28 cells. In H2052 and 211H cells, PD-L1 mRNA expression was significantly increased compared to other MPM cell lines; YAP knockdown by small interfering RNA decreased PD-L1 protein and mRNA expression. Forced overexpression of the YAP gene increased PD-L1 protein expression in H2452 cells. Chromatin immunoprecipitation (ChIP) assay showed the precipitation of PD-L1 enhancer region encompassing 2 putative YAP-TEAD-binding sites in H2052 cells. We found that, in human MPM tissue microarray samples, YAP and PD-L1 concurrently expressed in immunohistochemistry stain (n = 70, P

Malignant mesothelioma is an aggressive cancer that is resistant to current therapy. The poor prognosis of mesothelioma has been associated with elevated Yes-associated protein (YAP) activity. In this study, we evaluated the effect of targeting YAP in mesothelioma. First, we comprehensively studied YAP activity in five mesothelioma cell lines (211H, H2052, H290, MS-1 and H2452) and one normal mesothelial cell line (LP9). We found decreased phospho-YAP to YAP protein ratio and consistently increased GTIIC reporter activity in 211H, H2052 and H290 compared to LP9. The same three cell lines (IC50 s < 1 μM) were more sensitive than LP9 (IC50 = 3.5 μM) to the YAP/TEAD inhibitor verteporfin. We also found that verteporfin significantly reduced YAP protein level, mRNA levels of YAP downstream genes and GTIIC reporter activity in the same three cell lines, indicating inhibition of YAP signaling by verteporfin. Verteporfin also impaired invasion and tumoursphere formation ability of H2052 and H290. To validate the effect of specific targeting YAP in mesothelioma cells, we down-regulated YAP by siRNA. We found siYAP significantly decreased YAP transcriptional activity and impaired invasion and tumoursphere formation ability of H2052 and H290. Furthermore, forced overexpression of YAP rescued GTIIC reporter activity and cell viability after siYAP targeting 3'UTR of YAP. Finally, we found concurrent immunohistochemistry staining of ROCK2 and YAP (P < 0.05). Inhibition of ROCK2 decreased GTIIC reporter activity in H2052 and 211H suggesting that Rho/ROCK signaling also contributed to YAP activation in mesothelioma cells. Our results indicate that YAP may be a potential therapeutic target in mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive cancer for which more effective treatments are needed. In this study, strong to moderate staining of MET and ERK5 was detected in 67.1 and 48% of the analyzed 73 human mesothelioma tumors, and significant correlation of MET and ERK5 expression was identified (P