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.

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.

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.

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.

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.].

[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.