ACSL4 is a predictive biomarker of sorafenib sensitivity in hepatocellular carcinoma.

Sorafenib is the first-line treatment of advanced hepatocellular carcinoma (HCC). However, there is a lack of validated biomarkers to predict sorafenib sensitivity. In this study we investigated the role of ACSL4, a positive-activating enzyme of ferroptosis, in sorafenib-induced cell death and HCC patient outcome. We showed that ACSL4 protein expression was negatively associated with IC50 values of sorafenib in a panel of HCC cell lines (R = -0.952, P < 0.001). Knockdown of ACSL4 expression by specific siRNA/sgRNA significantly attenuated sorafenib-induced lipid peroxidation and ferroptosis in Huh7 cells, and also rescued sorafenib-induced inhibition of xenograft tumor growth in vivo. We selected 29 HCC patients with surgery as primary treatment and sorafenib as postoperative adjunct therapy from a hospital-based cohort. A high proportion (66.7%) of HCC patients who had complete or partial responses to sorafenib treatment (according to the revised RECIST guideline) had higher ACSL4 expression in the pretreated HCC tissues, compared with those who had stable or progressed tumor growth (23.5%, P = 0.029). Since ACSL4 expression was independent of sorafenib treatment, it could serve as a useful predictive biomarker. Taken together, this study demonstrates that ACSL4 is essential for sorafenib-induced ferroptosis and useful for predicting sorafenib sensitivity in HCC. This study may have important translational impacts in precise treatment of HCC.

Artesunate synergizes with sorafenib to induce ferroptosis in hepatocellular carcinoma.

Sorafenib is the first-line medication for advanced hepatocellular carcinoma (HCC), but it can only extend limited survival. It is imperative to find a combination strategy to increase sorafenib efficacy. Artesunate is such a preferred candidate, because artesunate is clinically well-tolerated and more importantly both drugs can induce ferroptosis through different mechanisms. In this study we investigated the combined effect of sorafenib and artesunate in inducing ferroptosis of HCC and elucidated the involved molecular mechanisms. We showed that artesunate greatly enhanced the anticancer effects of low dose of sorafenib against Huh7, SNU-449, and SNU-182 HCC cell lines in vitro and against Huh7 cell xenograft model in Balb/c nude mice. The combination index method confirmed that the combined effect of sorafenib and artesunate was synergistic. Compared with the treatment with artesunate or sorafenib alone, combined treatment induced significantly exacerbated lipid peroxidation and ferroptosis, which was blocked by N-acetyl cysteine and ferroptosis inhibitors liproxstatin-1 and deferoxamine mesylate, but not by inhibitors of other types of cell death (z-VAD, necrostatin-1 and belnacasan). In Huh7 cells, we demonstrated that the combined treatment induced oxidative stress and lysosome-mediated ferritinophagy, two essential aspects of ferroptosis. Sorafenib at low dose mainly caused oxidative stress through mitochondrial impairments and SLC7A11-invovled glutathione depletion. Artesunate-induced lysosome activation synergized with sorafenib-mediated pro-oxidative effects by promoting sequential reactions including lysosomal cathepsin B/L activation, ferritin degradation, lipid peroxidation, and consequent ferroptosis. Taken together, artesunate could be repurposed to sensitize sorafenib in HCC treatment. The combined treatment can be easily translated into clinical applications.

Geniposide attenuates postischemic long-term potentiation via GluN2A.

N-Methyl-D-aspartate receptor (NMDAR)-induced antioxidation is a significant cause of neuronal injury after ischemic stroke. In a previous work, we verified the neuroprotective roles of geniposide during tMCAO in vivo. However, it remains unknown whether geniposide ameliorates injury to hippocampal neurons during Ischemic Long Term Potentiation (iLTP) induction in vitro. After induction of cells oxygen-glucose deprivation or hydrogen peroxide, the protection of geniposide evaluated by MTT assay and electrophysiological tests. In this study, we suggested neuronal cell apoptosis was attenuated by geniposide. Furthermore, field excitatory postsynaptic potentials (fEPSCs) following postischemic LTP were assessed by electrophysiological tests. Finally, we determined that medium and high doses of geniposide attenuated oxidative stress insult and improved iLTP. Importantly, these effects were abolished by cotreatment with geniposide and the GluN2A antagonist NVP. In contrast, the GluN2B inhibitor ifenprodil failed to have an effect. In conclusion, we suggest for the first time that treatment with geniposide can attenuate postischemic LTP induction in a concentration-dependent manner. We infer that GluN2A-containing NMDARs are involved in the neuroprotection induced by geniposide treatment in ischemia.

Geniposide Attenuates Post-Ischaemic Neurovascular Damage via GluN2A/AKT/ ERK-Dependent Mechanism.

BACKGROUND/AIMS: Calcium-permeable ionotropic NMDAR-mediated hyperactivity is regarded as the critical factor in modulating the development of ischaemic stroke. Recently, there has been increasing interest in preventing post-stroke neuronal death by focusing on intervening in the function of subpopulations of NMDARs and their downstream signalling. Geniposide, an iridoid glycoside, has been found to have cytoprotective functions in various conditions. However, it is still unclear whether and how geniposide affects neuronal insult under experimental stroke. METHODS: We demonstrate that dose-dependent geniposide significantly decreased the infarct volume in tMCAO models. RESULTS: A medium level of geniposide improved anti-apoptotic functions and inhibited BBB leakage/haemorrhage via elevating GluN2A-containing NMDAR expression in tMCAO rats. Importantly, these effects could be eliminated by co-treatment of geniposide with the GluN2A antagonist NVP but not the GluN2B inhibitor ifenprodil. Moreover, geniposide's protection was due to the enhancement of GluN2A-dependent survival signals, including pAKT, pERK and PSD-95. CONCLUSION: The results suggest that geniposide protects neurons against post-ischaemic neurovascular injury through the activation of GluN2A/AKT/ERK pathways. As a very promising natural agent, geniposide may be a future therapeutic for stroke patients.

[Clinical effect of combination therapy with high-frequency oscillation ventilation, pulmonary surfactant and inhaled nitric oxide in the treatment of neonatal hypoxemic respiratory failure].

OBJECTIVE: To investigate the clinical effect of combination therapy with high-frequency oscillation ventilation (HFOV), pulmonary surfactant (PS) and inhaled nitric oxide (iNO) in the treatment of neonatal hypoxemic respiratory failure (HRF). METHODS: A total of 116 neonates with HRF were studied, and they were randomly divided into two groups: triple therapy (n=58) and dual therapy (n=58). The triple therapy group received HFOV, PS, and iNO, while the dual therapy group received HFOV and iNO. Blood gas values, PaO2/FiO2 (P/F), oxygenation index (OI), and pulmonary arterial pressure (PA) were determined before treatment and after 24 and 48 hours of treatment. Among the neonates with different P/F ratios and OI values and with or without persistent pulmonary hypertension of the newborn (PPHN), the treatment outcomes of two groups were compared. RESULTS: The durations of mechanical ventilation and iNO therapy in the triple therapy group were significantly shorter than in the dual therapy group (P<0.01). After 24 and 48 hours of treatment, the triple therapy group had significantly improve PaO2 and PaCO2 compared with the dual therapy group (P<0.01). After 24 and 48 hours of treatment, the neonates with PPHN in the triple therapy group had significantly decreased PA compared with the dual therapy group (P<0.01). In the cases with a P/F ratio of ≤50, the triple group had a significantly higher cure rate than the dual therapy group (P<0.05). In both groups, the P/F ratios of the neonates who died were significantly lower than those of survivors (P<0.01). In the cases with an OI of ≥40, the triple group had a significantly higher cure rate than the dual therapy group (P<0.05). In both groups, the OI values of the neonates who died were significantly higher than those of survivors (P<0.01). In neonates with PPHN, the triple group had a significantly higher cure rate than the dual therapy group (P<0.05). The triple therapy group had a significantly shorter length of hospital stay (P<0.01) and a significantly higher cure rate (P<0.05) compared with the dual therapy group. There were no significant differences in complications between the two groups (P>0.05). No severe side effect was found during the treatment in either group. CONCLUSIONS: Triple therapy with HFOV, PS and iNO is a more effective treatment for neonatal HRF compared with the dual therapy with HFOV and iNO. The triple therapy can significantly improve oxygenation and survival rate, providing a new treatment for the neonates with HRF, especially the critical cases who suffer severe lung disease with PPHN and have a P/F ratio of ≤50 or an OI of ≥40.

Simultaneous treatment with sorafenib and glucose restriction inhibits hepatocellular carcinoma in vitro and in vivo by impairing SIAH1-mediated mitophagy.

Transarterial chemoembolization (TACE) is the first-line treatment for unresectable intermediate-stage hepatocellular carcinoma (HCC). It is of high clinical significance to explore the synergistic effect of TACE with antiangiogenic inhibitors and the molecular mechanisms involved. This study determined that glucose, but not other analyzed nutrients, offered significant protection against cell death induced by sorafenib, as indicated by glucose deprivation sensitizing cells to sorafenib-induced cell death. Next, this synergistic effect was found to be specific to sorafenib, not to lenvatinib or the chemotherapeutic drugs cisplatin and doxorubicin. Mechanistically, sorafenib-induced mitophagy, as indicated by PINK1 accumulation, increased the phospho-poly-ubiquitination modification, accelerated mitochondrial membrane protein and mitochondrial DNA degradation, and increased the amount of mitochondrion-localized mKeima-Red engulfed by lysosomes. Among several E3 ubiquitin ligases tested, SIAH1 was found to be essential for inducing mitophagy; that is, SIAH1 silencing markedly repressed mitophagy and sensitized cells to sorafenib-induced death. Notably, the combined treatment of glucose restriction and sorafenib abolished ATP generation and mitophagy, which led to a high cell death rate. Oligomycin and antimycin, inhibitors of electron transport chain complexes, mimicked the synergistic effect of sorafenib with glucose restriction to promote cell death mediated via mitophagy inhibition. Finally, inhibition of the glucose transporter by canagliflozin (a clinically available drug used for type-II diabetes) effectively synergized with sorafenib to induce HCC cell death in vitro and to inhibit xenograft tumor growth in vivo. This study demonstrates that simultaneous treatment with sorafenib and glucose restriction is an effective approach to treat HCC, suggesting a promising combination strategy such as transarterial sorafenib-embolization (TASE) for the treatment of unresectable HCC.

Glycine attenuates cerebrovascular remodeling via glycine receptor alpha 2 and vascular endothelial growth factor receptor 2 after stroke.

As a dual-acting neurotransmitter, glycine plays critical roles in cerebral ischemia by activating both glycine receptors (GlyRs) and N-methyl-D-aspartate acid receptors (NMDARs). However, the involvement of glycine receptor alpha 2 (GlyRa2) in cerebral ischemia has not been explored. The objective of this study was to determine the mechanism of action of GlyRa2 in cerebrovascular remodeling. After induction of rat tMCAO, levels of the GLRA2 gene and GlyRa2 protein were examined using q-PCR, western blot, and immunohistochemical analyses. Blood-brain barrier permeability, and the presence of hemorrhage and arteriosclerosis were also analyzed. The underlying mechanism of vascular remodeling was examined using immunohistochemical and immunofluorescence analyses. Both the GLRA2 gene and GlyRa2 protein were altered sharply after stroke. GlyRa2 of vascular origin appears to play a protective role after glycine treatment for ischemia. Blockade of GlyRa2 by the addition of cyclothiazide was found to abolish previous improvements in cerebrovascular survival after glycine treatment for tMCAO in rats. GlyRa2-dependent neurovascular remodeling was found to be correlated with the vascular endothelial growth factor receptor 2 (VEGFR2) pathways. These results suggest that vascular-derived GlyRa2 protects against post-ischemic injury. Vascular protection via GlyRa2 is due to VEGFR2/pSTAT3 signaling.

Distinct effects of anti-diabetic medications on liver cancer risk and patient survival.

Type 2 diabetes mellitus (T2DM) is a pandemic metabolic disease worldwide. Multiple types of cancer, particularly liver cancer, are closely associated with T2DM. As a result, there is growing interest in investigating whether anti-diabetic medications could lower cancer risks in the population and even prolong patient survival among those with concurrent cancer. There are many types of anti-diabetic medications available in the clinic. The present study reviewed how different anti-diabetic drugs affect cancer risk and patient survival. On the one hand, multiple retrospective studies have shown that the different anti-diabetic medications have distinct effects on cancer risks. Insulin-raising drugs, including exogenous insulin, increased cancer risks, while drugs potentiating insulin sensitivity like metformin reduced cancer risks. On the other hand, the effects of anti-diabetic medications on patient survival are relatively less studied, except limited reports in liver cancer and pancreatic cancer. It seems that metformin could extend overall survival in patients of early-stage cancer. In contrast in the advanced cancer with metastasis, metformin has no effect or even worsens cancer mortality. It is yet unknown whether these distinct effects of metformin are attributable to the severity of the cancer staging or to the drug interactions between metformin and other medications. This question warrants reconsideration of the current clinical practice in the control of T2DM. Future large-scale prospective studies are needed to resolve this.

Corrigendum: Quercetin Induces Apoptosis Via Downregulation of VEGF/Akt Signaling Pathway in Acute Myeloid Leukemia Cells.

[This corrects the article DOI: 10.3389/fphar.2020.534171.].

Quercetin Induces Apoptosis via Downregulation of Vascular Endothelial Growth Factor/Akt Signaling Pathway in Acute Myeloid Leukemia Cells.

Acute myeloid leukemia (AML) is an aggressive haematological malignancy characterized by highly proliferative accumulation of immature and dysfunctional myeloid cells. Quercetin (Qu), one kind of flavonoid, exhibits anti-cancer property in multiple types of solid tumor, but its effect on acute myeloid leukemia is less studied, and the underlying mechanisms still largely unknown. This study aimed to explore the specific target and potential mechanism of quercetin-induced cell death in AML. First, we found that quercetin induces cell death in the form of apoptosis, which was caspase dependent. Second, we found that quercetin-induced apoptosis depends on the decrease of mitochondria membrane potential (MMP) and Bcl-2 proteins. With quantitative chemical proteomics, we observed the downregulation of VEGFR2 and PI3K/Akt signaling in quercetin-treated cells. Consistently, cell studies also identified that VEGFR2 and PI3K/Akt signaling pathways are involved in the action of quercetin on mitochondria and Bcl-2 proteins. The decrease of MMP and cell death could be rescued when PI3K/Akt signaling is activated, suggesting that VEGFR2 and PI3K/Akt exert as upstream regulators for quercetin effect on apoptosis induction in AML cells. In conclusion, our findings from this study provide convincing evidence that quercetin induces cell death via downregulation of VEGF/Akt signaling pathways and mitochondria-mediated apoptosis in AML cells.