TAK-981, a SUMOylation inhibitor, suppresses AML growth immune-independently.

Acute myeloid leukemia (AML) generally has an unsatisfactory prognosis despite the recent introduction of new regimens, including targeted agents and antibodies. To find a new druggable pathway, we performed integrated bioinformatic pathway screening on large OHSU and MILE AML databases, discovered the SUMOylation pathway, and validated it independently with an external data set (totaling 2959 AML and 642 normal sample data). The clinical relevance of SUMOylation in AML was supported by its core gene expression which is correlated with patient survival, European LeukemiaNet 2017 risk classification, and AML-relevant mutations. TAK-981, a first-in-class SUMOylation inhibitor currently under clinical trials for solid tumors, showed antileukemic effects with apoptosis induction, cell-cycle arrest, and induction of differentiation marker expression in leukemic cells. It exhibited potent nanomolar activity, often stronger than that of cytarabine, which is part of the standard of care. TAK-981's utility was further demonstrated in in vivo mouse and human leukemia models as well as patient-derived primary AML cells. Our results also indicate direct and cancer cell-inherent anti-AML effects by TAK-981, different from the type 1 interferon and immune-dependent mechanism in a previous solid tumor study. Overall, we provide a proof-of-concept for SUMOylation as a new targetable pathway in AML and propose TAK-981 as a promising direct anti-AML agent. Our data should prompt studies on optimal combination strategies and transitions to clinical trials in AML.

GPX8 regulates clear cell renal cell carcinoma tumorigenesis through promoting lipogenesis by NNMT.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC), with its hallmark phenotype of high cytosolic lipid content, is considered a metabolic cancer. Despite the implication of this lipid-rich phenotype in ccRCC tumorigenesis, the roles and regulators of de novo lipid synthesis (DNL) in ccRCC remain largely unexplained. METHODS: Our bioinformatic screening focused on ccRCC-lipid phenotypes identified glutathione peroxidase 8 (GPX8), as a clinically relevant upstream regulator of DNL. GPX8 genetic silencing was performed with CRISPR-Cas9 or shRNA in ccRCC cell lines to dissect its roles. Untargeted metabolomics, RNA-seq analyses, and other biochemical assays (e.g., lipid droplets staining, fatty acid uptake, cell proliferation, xenograft, etc.) were carried out to investigate the GPX8's involvement in lipid metabolism and tumorigenesis in ccRCC. The lipid metabolic function of GPX8 and its downstream were also measured by isotope-tracing-based DNL flux measurement. RESULTS: GPX8 knockout or downregulation substantially reduced lipid droplet levels (independent of lipid uptake), fatty acid de novo synthesis, triglyceride esterification in vitro, and tumor growth in vivo. The downstream regulator was identified as nicotinamide N-methyltransferase (NNMT): its knockdown phenocopied, and its expression rescued, GPX8 silencing both in vitro and in vivo. Mechanically, GPX8 regulated NNMT via IL6-STAT3 signaling, and blocking this axis suppressed ccRCC survival by activating AMPK. Notably, neither the GPX8-NNMT axis nor the DNL flux was affected by the von Hippel Lindau (VHL) status, the conventional regulator of ccRCC high lipid content. CONCLUSIONS: Taken together, our findings unravel the roles of the VHL-independent GPX8-NNMT axis in ccRCC lipid metabolism as related to the phenotypes and growth of ccRCC, which may be targeted for therapeutic purposes.

Non-bioenergetic roles of mitochondrial GPD2 promote tumor progression.

Rationale: Despite growing evidence for mitochondria's involvement in cancer, the roles of specific metabolic components outside the respiratory complex have been little explored. We conducted metabolomic studies on mitochondrial DNA (mtDNA)-deficient (ρ0) cancer cells with lower proliferation rates to clarify the undefined roles of mitochondria in cancer growth. Methods and results: Despite extensive metabolic downregulation, ρ0 cells exhibited high glycerol-3-phosphate (G3P) level, due to low activity of mitochondrial glycerol-3-phosphate dehydrogenase (GPD2). Knockout (KO) of GPD2 resulted in cell growth suppression as well as inhibition of tumor progression in vivo. Surprisingly, this was unrelated to the conventional bioenergetic function of GPD2. Instead, multi-omics results suggested major changes in ether lipid metabolism, for which GPD2 provides dihydroxyacetone phosphate (DHAP) in ether lipid biosynthesis. GPD2 KO cells exhibited significantly lower ether lipid level, and their slower growth was rescued by supplementation of a DHAP precursor or ether lipids. Mechanistically, ether lipid metabolism was associated with Akt pathway, and the downregulation of Akt/mTORC1 pathway due to GPD2 KO was rescued by DHAP supplementation. Conclusion: Overall, the GPD2-ether lipid-Akt axis is newly described for the control of cancer growth. DHAP supply, a non-bioenergetic process, may constitute an important role of mitochondria in cancer.

Igalan from Inula helenium (L.) suppresses the atopic dermatitis-like response in stimulated HaCaT keratinocytes via JAK/STAT3 signaling.

OBJECTIVE: This study aimed to evaluate the protective effect of igalan, a sesquiterpene lactone isolated from Inula helenium (L.), on inhibiting inflammation, regulating the epidermal differentiation gene expression, and reactive oxygen species scavenging in atopic dermatitis (AD)-like inflammatory keratinocytes. METHODS: HaCaT human keratinocytes were treated with igalan at indicated concentrations before being activated by a combination of TNF-α and IFN-γ or IL-4 representative for T-helper 1 and T-helper 2 cell cytokines, which are associated with AD pathogenesis. RESULTS: By inhibiting the NF-κB pathway as well as the STAT activation, igalan could downregulate several marker inflammatory genes in AD, such as TARC/CCL17, MDC/CCL22, and RANTES/CCL5. In contrast, igalan, acting as JAK inhibitor, could promote the mRNA expression levels of the genes FLG, LOR, KRT10, and DSC1, which encode for essential proteins responsible for keratinocyte differentiation, by inhibiting STAT3 signaling. Furthermore, igalan exerts its antioxidant effect through activating the Nrf2 pathway, triggering the expression of some enzymes that contribute to preventing intracellular ROS generation during inflammation. CONCLUSION: These findings indicate that igalan, via suppressing JAK/STAT3 signaling, could impair the production of pro-inflammatory chemokines and enhance expression levels of several genes involved in keratinocyte differentiation in AD-like stimulated keratinocytes.

Anticancer Activity of Smallanthus sonchifolius Methanol Extract against Human Hepatocellular Carcinoma Cells.

Background: This research aimed to investigate the cytotoxicity of methanol extract of Smallanthus sonchifolius leaf (YLE) against a human hepatocellular carcinoma cell line (HepG2). This plant is currently used as a traditional herbal remedy in the treatment of liver diseases in some rural parts of Myanmar. Methods: The cytotoxic activity of the plant extract against the cancerous cell line was assessed using an MTT assay. YLE demonstrated a significant effect (IC50 = 58.2 ± 1.9 µg/mL) on anti-cancer activity, which was further investigated using various assays including an in vitro cell migration assay, a colony formation assay, cell cycle analysis, western blot analysis, and a ROS assay. The significance of the phytochemical constituents of YLE could be identified using LC/Q-TOF-MS techniques. Results: We putatively identified the active components in YLE, which were possibly melampolide-type sesquiterpenoids. YLE showed an inhibitory effect on HepG2 cell proliferation and cell migration. YLE also induced cell cycle arrest and necrosis in a dose-dependent manner. Additionally, YLE significantly suppressed ROS formation in HepG2 cells. Conclusions: These findings suggest that YLE is sufficient for application as a promising anti-liver drug in herbal medicine.

Annona muricata Leaf Extract Triggered Intrinsic Apoptotic Pathway to Attenuate Cancerous Features of Triple Negative Breast Cancer MDA-MB-231 Cells.

Annona muricata L., known as graviola, is an evergreen plant of the tropical regions and is a rich source of natural products. Graviola has various biological activities, and it is best known for its anticancer activity. This study aimed to investigate the effects of crude graviola extract in vitro on breast cancer cells; in particular, we aimed to identify an agent against triple negative breast cancer (TNBC). We used the TNBC MDA-MB-231 cell line as the experimental model and the ER(+) non-TNBC MCF-7 breast cancer cell line as the control. We identified annonaceous acetogenins, including annonacin isomers, characteristic to this plant by using liquid chromatography tandem mass spectrometry (LC/MS/MS). We observed a significant decrease in the cell viability in both cell lines within 48 h, whereas impaired cell motility and invasiveness were observed only in the MDA-MB-231 cell line. While the MCF-7 cells showed an ER-dependent mechanism of apoptosis, the apoptosis of MDA-MB-231 cells was governed by an intrinsic apoptotic pathway triggered by graviola leaf extract (GLE).