Tanshinone IIA induces ER stress and JNK activation to inhibit tumor growth and enhance anti-PD-1 immunotherapy in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) remains at the forefront of new cancer cases, and there is an urgent need to find new treatments or improve the efficacy of existing therapies. In addition to the application in the field of cerebrovascular diseases, recent studies have revealed that tanshinone IIA (Tan IIA) has anticancer activity in a variety of cancers. PURPOSE: To investigate the potential anticancer mechanism of Tan IIA and its impact on immunotherapy in NSCLC. METHODS: Cytotoxicity and colony formation assays were used to detect the Tan IIA inhibitory effect on NSCLC cells. This research clarified the mechanisms of Tan IIA in anti-tumor and programmed death-ligand 1 (PD-L1) regulation by using flow cytometry, transient transfection, western blotting and immunohistochemistry (IHC) methods. Besides, IHC was also used to analyze the nuclear factor of activated T cells 1 (NFAT2) expression in NSCLC clinical samples. Two animal models including xenograft mouse model and Lewis lung cancer model were used for evaluating tumor suppressive efficacy of Tan IIA. We also tested the efficacy of Tan IIA combined with programmed cell death protein 1 (PD-1) inhibitors in Lewis lung cancer model. RESULTS: Tan IIA exhibited good NSCLC inhibitory effect which was accompanied by endoplasmic reticulum (ER) stress response and increasing Ca2+ levels. Moreover, Tan IIA could suppress the NFAT2/ Myc proto oncogene protein (c-Myc) signaling, and it also was able to control the Jun Proto-Oncogene(c-Jun)/PD-L1 axis in NSCLC cells through the c-Jun N-terminal kinase (JNK) pathway. High NFAT2 levels were potential factors for poor prognosis in NSCLC patients. Finally, animal experiments data showed a stronger immune activation phenotype, when we performed treatment of Tan IIA combined with PD-1 monoclonal antibody. CONCLUSION: The findings of our research suggested a novel mechanism for Tan IIA to inhibit NSCLC, which could exert anti-cancer effects through the JNK/NFAT2/c-Myc pathway. Furthermore, Tan IIA could regulate tumor PD-L1 levels and has the potential to improve the efficacy of PD-1 inhibitors.

Apoptotic and anti-Warburg effect of Morusin via ROS mediated inhibition of FOXM1/c-Myc signaling in prostate cancer cells.

Though Morusin is known to induce apoptotic, antiprolifertaive, and autophagic effects through several signaling pathways, the underlying molecular mechanisms of Morusin still remain unclear until now. To elucidate antitumor mechanism of Morusin, cytotoxicity assay, cell cycle analysis, Western blotting, TUNEL assay, RNA interference, immunofluorescense, immunoprecipitation, reactive oxygen species (ROS) measurement, and inhibitor study were applied in this study. Morusin enhanced cytotoxicity, increased the number of TUNEL positive cells, sub-G1 population and induced the cleavages of PARP and caspase3, attenuated the expression of HK2, PKM2, LDH, c-Myc, and Forkhead Box M1 (FOXM1) along with the reduction of glucose, lactate, and ATP in DU145 and PC3 cells. Furthermore, Morusin disrupted the binding of c-Myc and FOXM1 in PC-3 cells, which was supported by String and cBioportal database. Notably, Morusin induced c-Myc degradation mediated by FBW7 and suppressed c-Myc stability in PC3 cells exposed to MG132 and cycloheximide. Also, Morusin generated ROS, while NAC disrupted the capacity of Morusin to reduce the expression of FOXM1, c-Myc, pro-PARP, and pro-caspase3 in PC-3 cells. Taken together, these findings provide scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis plays a critical role in Morusin induced apoptotic and anti-Warburg effect in prostate cancer cells. Our findings support scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis is critically involved in apoptotic and anti-Warburg effect of Morusin in prostate cancer cells.

Oxidative stress enhances the therapeutic action of a respiratory inhibitor in MYC-driven lymphoma.

MYC is a key oncogenic driver in multiple tumor types, but concomitantly endows cancer cells with a series of vulnerabilities that provide opportunities for targeted pharmacological intervention. For example, drugs that suppress mitochondrial respiration selectively kill MYC-overexpressing cells. Here, we unravel the mechanistic basis for this synthetic lethal interaction and exploit it to improve the anticancer effects of the respiratory complex I inhibitor IACS-010759. In a B-lymphoid cell line, ectopic MYC activity and treatment with IACS-010759 added up to induce oxidative stress, with consequent depletion of reduced glutathione and lethal disruption of redox homeostasis. This effect could be enhanced either with inhibitors of NADPH production through the pentose phosphate pathway, or with ascorbate (vitamin C), known to act as a pro-oxidant at high doses. In these conditions, ascorbate synergized with IACS-010759 to kill MYC-overexpressing cells in vitro and reinforced its therapeutic action against human B-cell lymphoma xenografts. Hence, complex I inhibition and high-dose ascorbate might improve the outcome of patients affected by high-grade lymphomas and potentially other MYC-driven cancers.

The HDAC2/YY1/c-Myc signaling axis regulates lung cancer cell migration and proliferation.

Lung cancer is among the most aggressive types of malignant tumors that contributes to cancer-associated deaths worldwide with a high occurrence and fatality rate. Histone deacetylase 2 (HDAC2), prevent the aberrant transcription of a number of genes that are primarily responsible for controlling the cell cycle, cell proliferation, and signaling pathways in numerous cancers. Previous studies reported the role of HDACs and YY1 in the growth and development of several cancers. Although, it is noteworthy that remarkable efforts have been taken for the treatment of lung cancer using molecularly targeted therapies and chemotherapeutic agents, but the outcome is still poor for this critically persistent cancer. Therefore, the aim of the present study is to identify an efficacious, novel therapeutic biomarkers for the successful diagnosis of lung cancer at the early stage of the disease and the molecular insights involved. In the present study, qPCR and western bot data revealed that the expression level of HDAC2 and YY1 were upregulated in the cell lines and tumor samples of lung cancer patients. Moreover, MTT, qPCR, western blot, cell cycle analysis, and migration assays showed that inhibition of HDAC2 reduced YY1 expression, similarly, depletion of YY1 using knockdown approach inhibited the proliferation, migration, invasion, and blockage of the cell cycle by suppressing c-Myc in lung cancer cell lines. In conclusion, the current study findings support the notion that HDAC2's anticancer role was attributed through YY1 regulation by targeting c-Myc and could act as potential novel candidate biomarker for the lung cancer diagnosis.

Jiedu-Quyu-Ziyin Fang (JQZF) inhibits the proliferation and activation of B cells in MRL/lpr mice via modulating the AKT/mTOR/c-Myc signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jiedu-Quyu-Ziyin Fang (JQZF) is a new herbal formula improved based on "Sheng Ma Bie Jia Tang" in the Golden Chamber, has been proved to be effective in the treatment of SLE. The ability of JQZF to prevent lymphocyte growth and survival has been demonstrated in earlier investigations. However, the specific mechanism of JQZF on SLE has not been fully investigated. AIM OF THE STUDY: To reveal the potential mechanisms of JQZF inhibiting B cell proliferation and activation in MRL/lpr mice. MATERIALS AND METHODS: MRL/lpr mice were treated with low-dose, high-dose JQZF and normal saline for 6 weeks. The effect of JQZF on disease improvement in MRL/lpr mice was studied using enzyme-linked immunosorbent assay (ELISA), histopathological staining, serum biochemical parameters and urinary protein levels. The changes of B lymphocyte subsets in the spleen were analyzed by flow cytometry. The contents of ATP and PA in B lymphocytes from the spleens of mice were determined by ATP content assay kit and PA assay kit. Raji cells (a B lymphocyte line) were selected as the cell model in vitro. The effects of JQZF on the proliferation and apoptosis of B cells were detected by flow cytometry and CCK8. The effect of JQZF on the AKT/mTOR/c-Myc signaling pathway in B cells were detected via western blot. RESULTS: JQZF, especially at high dose, significantly improved the disease development of MRL/lpr mice. Flow cytometry results showed that JQZF affected the proliferation and activation of B cells. In addition, JQZF inhibited the production of ATP and PA in B lymphocytes. In vitro cell experiments further confirmed that JQZF can inhibit Raji proliferation and promote cell apoptosis through AKT/mTOR/c-Myc signaling pathway. CONCLUSION: JQZF may affect the proliferation and activation of B cells by inhibiting the AKT/mTOR/c-Myc signaling pathway.

[Effect of Morus alba extract sanggenon C on growth and proliferation of glioblastoma cells].

Glioblastoma is the most common primary cranial malignancy, and chemotherapy remains an important tool for its treatment. Sanggenon C(San C), a class of natural flavonoids extracted from Morus plants, is a potential antitumor herbal monomer. In this study, the effect of San C on the growth and proliferation of glioblastoma cells was examined by methyl thiazolyl tetrazolium(MTT) assay and 5-bromodeoxyuridinc(BrdU) labeling assay. The effect of San C on the tumor cell cycle was examined by flow cytometry, and the effect of San C on clone formation and self-renewal ability of tumor cells was examined by soft agar assay. Western blot and bioinformatics analysis were used to investigate the mechanism of the antitumor activity of San C. In the presence of San C, the MTT assay showed that San C significantly inhibited the growth and proliferation of tumor cells in a dose and time-dependent manner. BrdU labeling assay showed that San C significantly attenuated the DNA replication activity in the nucleus of tumor cells. Flow cytometry confirmed that San C blocked the cell cycle of tumor cells in G_0/G_1 phase. The soft agar clone formation assay revealed that San C significantly attenuated the clone formation and self-renewal ability of tumor cells. The gene set enrichment analysis(GSEA) implied that San C inhibited the tumor cell division cycle by affecting the myelocytomatosis viral oncogene(MYC) signaling pathway. Western blot assay revealed that San C inhibited the expression of cyclin through the regulation of the MYC signaling pathway by lysine demethylase 4B(KDM4B), which ultimately inhibited the growth and proliferation of glioblastoma cells and self-renewal. In conclusion, San C exhibits the potential antitumor activity by targeting the KDM4B-MYC axis to inhibit glioblastoma cell growth, proliferation, and self-renewal.

[Paeoniflorin induces apoptosis and cycle arrest in B-cell acute lymphoblastic leukemia cells by inhibiting SENP1/c-Myc signaling pathway].

The effect of paeoniflorin on apoptosis and cell cycle in human B-cell acute lymphoblastic leukemia(B-ALL) and its underlying mechanism were investigated in this study. Nalm-6 and SUP-B15 cells were cultured in vitro and divided into control group(0 µg·mL~(-1)) and experimental groups(200, 400, and 800 µg·mL~(-1) paeoniflorin). Cell counting kit-8(CCK-8) was used to measure the viability of Nalm-6 and SUP-B15 cells, and cell apoptosis and cell cycle distribution were analyzed by flow cytometry. Western blot was used to detect the protein levels of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase(cleaved PARP), c-Myc, and small ubiquitin-like modifier-specific protease 1(SENP1). The mRNA levels of c-Myc and SENP1 in acute lymphoblastic leukemia(ALL) patients were analyzed based on the Oncomine database. AutoDock was used for molecular docking to analyze the interaction of paeoniflorin with c-Myc and SENP1 proteins. RESULTS:: showed that paeoniflorin inhibited the viability of Nalm-6 and SUP-B15 cells in concentration and time-dependent manners. Compared with the control group, paeoniflorin significantly up-regulated the expression of apoptosis-related proteins cleaved caspase-3 and cleaved PARP to induce apoptosis, evidently increased the proportion of G_2/M phase cells and induced G_2/M phase arrest, and obviously down-regulated the expression of c-Myc and SENP1 proteins in Nalm-6 and SUP-B15 cells. The mRNA levels of c-Myc and SENP1 in ALL patients were higher than those in the normal cell. Molecular docking demonstrated that paeoniflorin had good binding to c-Myc and SENP1 proteins. In summary, paeoniflorin inhibits the proliferation of Nalm-6 and SUP-B15 cells by inducing apoptosis and G_2/M phase arrest, which may be related to the down-regulation of c-Myc and SENP1 proteins.

[Research progress on role of traditional Chinese medicine in hepatic fibrosis based on miRNA-mediated activation of NLRP3 inflammasome].

In recent years, liver fibrosis has become a hotspot in the field of liver diseases. MicroRNA(miRNA)-mediated Nod-like receptor pyrin domain containing 3(NLRP3) inflammasome activation is pivotal in the pathogenesis of liver fibrosis. The present study mainly discussed the role of miRNA-mediated NLRP3 inflammasome activation in the pathogenesis of liver fibrosis. Different miRNA molecules regulated liver fibrosis by mediating NLRP3 inflammasome activation, including miRNA-350-3 p(miR-350-3 p)/interleukin-6(IL-6)-mediated signal transducer and activator of transcription 3(STAT3)/c-myc signaling pathway, miR-148 a-induced autophagy and apoptosis of hepatic stellate cells via hedgehog signaling pathway, miR-155-mediated NLRP3 inflammasome by the negative feedback of the suppressor of cytokine signaling-1(SOCS-1), miR-181 a-mediated downstream NLRP3 inflammatory pathway activation through mitogen-activated protein kinase kinase(MEK)/extracellular signal-regulated kinase(ERK)/nuclear transcription factor κB(NF-κB) inflammatory pathway, miR-21-promoted expression of NF-κB and NLRP3 of RAW264.7 cells in mice by inhibiting tumor necrosis factor-α inducible protein 3(A20), and miR-20 b-promoted expression of IL-1ß and IL-18 by activating NLRP3 signaling pathway. Additionally, the anti-liver fibrosis mechanism of different active components in Chinese medicines(such as Curcumae Rhizoma, Glycyrrhizae Radix et Rhizoma, Aurantii Fructus, Polygoni Cuspidati Rhizoma et Radix, Moutan Cortex, Paeoniae Radix Alba, Epimedii Folium, and Cinnamomi Cortex) was also explored based on the anti-liver fibrosis effect of miRNA-mediated NLRP3 inflammasome activation.

Epigenetic drug screening defines a PRMT5 inhibitor-sensitive pancreatic cancer subtype.

Systemic therapies for pancreatic ductal adenocarcinoma (PDAC) remain unsatisfactory. Clinical prognosis is particularly poor for tumor subtypes with activating aberrations in the MYC pathway, creating an urgent need for novel therapeutic targets. To unbiasedly find MYC-associated epigenetic dependencies, we conducted a drug screen in pancreatic cancer cell lines. Here, we found that protein arginine N-methyltransferase 5 (PRMT5) inhibitors triggered an MYC-associated dependency. In human and murine PDACs, a robust connection of MYC and PRMT5 was detected. By the use of gain- and loss-of-function models, we confirmed the increased efficacy of PRMT5 inhibitors in MYC-deregulated PDACs. Although inhibition of PRMT5 was inducing DNA damage and arresting PDAC cells in the G2/M phase of the cell cycle, apoptotic cell death was executed predominantly in cells with high MYC expression. Experiments in primary patient-derived PDAC models demonstrated the existence of a highly PRMT5 inhibitor-sensitive subtype. Our work suggests developing PRMT5 inhibitor-based therapies for PDAC.

The Diminishment of Novel Endometrial Carcinoma-Derived Stem-like Cells by Targeting Mitochondrial Bioenergetics and MYC.

Cancer stem cells (CSCs) are a small subpopulation of tumor cells harboring properties that include self-renewal, multi-lineage differentiation, tumor reconstitution, drug resistance and invasiveness, making them key players in tumor relapse. In the present paper, we develop new CSC models and analyze the molecular pathways involved in survival to identify targets for the establishment of novel therapies. Endometrial carcinoma-derived stem-like cells (ECSCs) were isolated from carcinogenic gynecological tissue and analyzed regarding their expression of prominent CSC markers. Further, they were treated with the MYC-signaling inhibitor KJ-Pyr-9, chemotherapeutic agent carboplatin and type II diabetes medication metformin. ECSC populations express common CSC markers, such as Prominin-1 and CD44 antigen as well as epithelial-to-mesenchymal transition markers, Twist, Snail and Slug, and exhibit the ability to form free-floating spheres. The inhibition of MYC signaling and treatment with carboplatin as well as metformin significantly reduced the cell survival of ECSC-like cells. Further, treatment with metformin significantly decreased the mitochondrial membrane potential of ECSC-like cells, while the extracellular lactate concentration was increased. The established ECSC-like populations represent promising in vitro models to further study the contribution of ECSCs to endometrial carcinogenesis. Targeting MYC signaling as well as mitochondrial bioenergetics has shown promising results in the diminishment of ECSCs, although molecular signaling pathways need further investigations.

MYC Promotes Tyrosine Kinase Inhibitor Resistance in ROS1-Fusion-Positive Lung Cancer.

Targeted therapy of ROS1-fusion-driven non-small cell lung cancer (NSCLC) has achieved notable clinical success. Despite this, resistance to therapy inevitably poses a significant challenge. MYC amplification was present in ∼19% of lorlatinib-resistant ROS1-driven NSCLC. We hypothesized that MYC overexpression drives ROS1-TKI resistance. Using complementary approaches in multiple models, including a MYC-amplified patient-derived cell line and xenograft (LUAD-0006), we established that MYC overexpression induces broad ROS1-TKI resistance. Pharmacologic inhibition of ROS1 combined with MYC knockdown were essential to completely suppress LUAD-0006 cell proliferation compared with either treatment alone. We interrogated cellular signaling in ROS1-TKI-resistant LUAD-0006 and discovered significant differential regulation of targets associated with cell cycle, apoptosis, and mitochondrial function. Combinatorial treatment of mitochondrial inhibitors with crizotinib revealed inhibitory synergism, suggesting increased reliance on glutamine metabolism and fatty-acid synthesis in chronic ROS1-TKI treated LUAD-0006 cells. In vitro experiments further revealed that CDK4/6 and BET bromodomain inhibitors effectively mitigate ROS1-TKI resistance in MYC-overexpressing cells. Notably, in vivo studies demonstrate that tumor control may be regained by combining ROS1-TKI and CDK4/6 inhibition. Our results contribute to the broader understanding of ROS1-TKI resistance in NSCLC. IMPLICATIONS: This study functionally characterizes MYC overexpression as a novel form of therapeutic resistance to ROS1 tyrosine kinase inhibitors in non-small cell lung cancer and proposes rational combination treatment strategies.

Formononetin represses cervical tumorigenesis by interfering with the activation of PD-L1 through MYC and STAT3 downregulation.

A. membranaceus is a traditional Chinese medicine that regulates blood sugar levels, suppresses inflammation, protects the liver, and enhances immunity. In addition, A. membranaceus is also widely used in diet therapy and is a well-known health tonic. Formononetin is a natural product isolated from A. membranaceus that has multiple biological functions, including anti-cancer activity. However, the mechanism by which formononetin inhibits tumor growth is not fully understood. In this present study, we demonstrated that formononetin suppresses PD-L1 protein synthesis via reduction of MYC and STAT3 protein expression. Furthermore, formononetin markedly reduced the expression of MYC protein via the RAS/ERK signaling pathway and inhibited STAT3 activation through JAK1/STAT3 pathway. Co-immunoprecipitation experiments illustrated that formononetin suppresses protein expression of PD-L1 by interfering with the interaction between MYC and STAT3. Meanwhile, formononetin promoted PD-L1 protein degradation via TFEB and TFE3-mediated lysosome biogenesis. T cell killing assay revealed that formononetin could enhance the activity of cytotoxic T lymphocytes (CTLs) and restore ability to kill tumor cells in a co-culture system of T cells and tumor cells. In addition, formononetin inhibited cell proliferation, tube formation, cell migration, and promoted tumor cell apoptosis by suppressing PD-L1. Finally, the inhibitory effect of formononetin on tumor growth was confirmed in a murine xenograft model. The present study revealed the anti-tumor potential of formononetin, and the findings should support further research and development of anti-cancer drugs for cervical cancer.

Research progress on role of traditional Chinese medicine in hepatic fibrosis based on miRNA-mediated activation of NLRP3 inflammasome / 中国中药杂志

In recent years, liver fibrosis has become a hotspot in the field of liver diseases. MicroRNA(miRNA)-mediated Nod-like receptor pyrin domain containing 3(NLRP3) inflammasome activation is pivotal in the pathogenesis of liver fibrosis. The present study mainly discussed the role of miRNA-mediated NLRP3 inflammasome activation in the pathogenesis of liver fibrosis. Different miRNA molecules regulated liver fibrosis by mediating NLRP3 inflammasome activation, including miRNA-350-3 p(miR-350-3 p)/interleukin-6(IL-6)-mediated signal transducer and activator of transcription 3(STAT3)/c-myc signaling pathway, miR-148 a-induced autophagy and apoptosis of hepatic stellate cells via hedgehog signaling pathway, miR-155-mediated NLRP3 inflammasome by the negative feedback of the suppressor of cytokine signaling-1(SOCS-1), miR-181 a-mediated downstream NLRP3 inflammatory pathway activation through mitogen-activated protein kinase kinase(MEK)/extracellular signal-regulated kinase(ERK)/nuclear transcription factor κB(NF-κB) inflammatory pathway, miR-21-promoted expression of NF-κB and NLRP3 of RAW264.7 cells in mice by inhibiting tumor necrosis factor-α inducible protein 3(A20), and miR-20 b-promoted expression of IL-1β and IL-18 by activating NLRP3 signaling pathway. Additionally, the anti-liver fibrosis mechanism of different active components in Chinese medicines(such as Curcumae Rhizoma, Glycyrrhizae Radix et Rhizoma, Aurantii Fructus, Polygoni Cuspidati Rhizoma et Radix, Moutan Cortex, Paeoniae Radix Alba, Epimedii Folium, and Cinnamomi Cortex) was also explored based on the anti-liver fibrosis effect of miRNA-mediated NLRP3 inflammasome activation.

Effects of ethanolic extracts of Quercus, Cirsium vulgare, and Falcaria vulgaris on gastric ulcer, antioxidant and inflammatory indices, and gene expression in rats.

INTRODUCTION: Gastric ulcer is a multifaceted process and is usually caused by mucosal damage. Herbal medicines have received much attention considering the side effects of chemical drugs. Nowadays, the use of herbal medicines has received much attention considering the side effects of chemical drugs. Quercus brantii Lindl, Cirsium vulgare (Savi) Ten, and Falcaria vulgaris Bernh are plants used as traditional phytomedicine for gastric ulcer diseases. AIM OF THE STUDY: This study was aimed to investigate the protective effects of hydroalcoholic extracts of these herbs on ethanol-induced gastric ulceration, in addition, to investigate the antioxidant, anti-inflammatory, and gene expression. MATERIALS AND METHODS: Thirty Sprague Dawley rats, (200-250 g), were divided into six groups: Control: intact animals; sham: gavaged with distilled water (14 days); negative control: gavaged with 20 mg/kg of omeprazole (14 days); experimental groups I, II, and III: gavaged with 500 mg/kg of the extract of Falcaria vulgaris, Quercus brantii, and Cirsium vulgare, respectively, (14 days). The number of ulcers and pathological parameters were assessed. The serum superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, total antioxidant capacity, albumin, total protein, haptoglobin, alpha-1-acid glycoprotein, total globulin, alpha-2-macroglobulin, C-fos, C-myc, and Caspase-9 were measured by ELISA and RT-PCR. RESULTS: The extracts significantly reduced gastric ulcer (52.33%). The results showed that the Quercus brantii extract was more effective. There were significant differences between the serum levels of alpha-1-acid glycoprotein and those of alpha-2-macroglobulin. Also, there was a significant difference in the serum level of antioxidant parameters. Changes in the expression of the genes also confirmed the results suggested by other parameters. The expression levels of C-fos, C-myc, and caspase-9 were decreased, but the Bcl-2 expression increased. CONCLUSION: The hydro-alcoholic extracts revealed various protection and noticeable change in the expression of caspase-9, C-myc, C-fos, and Bcl-2 genes in rats.

Demethyleneberberine induces cell cycle arrest and cellular senescence of NSCLC cells via c-Myc/HIF-1α pathway.

BACKGROUND: Demethyleneberberine (DMB) is a natural active component of medicinal plant Cortex phellodendri chinensis with favorable bioactivity. However, the role of DMB in suppressing non-small cell lung cancer (NSCLC) remains unknown. PURPOSE: In this study, we aimed to examine the effect and underlying mechanism of DMB in suppressing NSCLC. METHODS: CCK8 assay and colony formation assay were utilized to assess the efficiency of DMB on the viability and colony formation capacity of NSCLC cells. Flow cytometry and ß-Galactosidase Staining Kit were utilized to determine the efficiency of DMB on the cell cycle and cellular senescence of NSCLC cells. RT-qPCR and Western blot were used to detect the effect of DMB on cell cycle and cellular senescence related gene and protein expression of NSCLC cells. In vivo tumor model was established to evaluate the anti NSCLC effect of DMB. In addition, RNA-seq analysis was performed to detect the differential gene expression after DMB treatments. RESULTS: In this study, we revealed that DMB exhibits efficient inhibitory effect on NSCLC cell proliferation and tumor xenografts growth in vivo. We also demonstrated that DMB could inhibit cell migration by suppressing epithelial-mesenchymal transition (EMT) and trigger cell cycle arrest by down-regulating the expression of cell cycle related genes in NSCLC cells. In addition, DMB treatment efficiently induces cellular senescence of NSCLC cells. From the RNA-seq analysis, we found that DMB accelerates senescence through suppressing HIF-1α expression, which was further elucidated by overexpressing HIF-1α in NSCLC to reduce the inhibitory effect of DMB. Furthermore, we also revealed that DMB decreases the expression of c-Myc, an up-stream protein of HIF-1α. CONCLUSIONS: Taken together, we first report that DMB inhibits NSCLC progress through inducing cell cycle arrest and triggering cellular senescence by downregulating c-Myc/HIF-1α pathway.

Discovery of an Orally Efficacious MYC Inhibitor for Liver Cancer Using a GNMT-Based High-Throughput Screening System and Structure-Activity Relationship Analysis.

Glycine-N-methyl transferase (GNMT) downregulation results in spontaneous hepatocellular carcinoma (HCC). Overexpression of GNMT inhibits the proliferation of liver cancer cell lines and prevents carcinogen-induced HCC, suggesting that GNMT induction is a potential approach for anti-HCC therapy. Herein, we used Huh7 GNMT promoter-driven screening to identify a GNMT inducer. Compound K78 was identified and validated for its induction of GNMT and inhibition of Huh7 cell growth. Subsequently, we employed structure-activity relationship analysis and found a potent GNMT inducer, K117. K117 inhibited Huh7 cell growth in vitro and xenograft in vivo. Oral administration of a dosage of K117 at 10 mpk (milligrams per kilogram) can inhibit Huh7 xenograft in a manner equivalent to the effect of sorafenib at a dosage of 25 mpk. A mechanistic study revealed that K117 is an MYC inhibitor. Ectopic expression of MYC using CMV promoter blocked K117-mediated MYC inhibition and GNMT induction. Overall, K117 is a potential lead compound for HCC- and MYC-dependent cancers.

Momordin Ic induces G0/1 phase arrest and apoptosis in colon cancer cells by suppressing SENP1/c-MYC signaling pathway.

Momordin Ic (MI) is a natural pentacyclic triterpenoid enriched in various Chinese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. Studies have shown that MI presents antitumor properties in liver and prostate cancers. However, the activity and potential mechanisms of MI against colorectal cancer remain elusive. Here, we showed that MI inhibited cell proliferation with G0/1 phase cell cycle arrest in colon cancer cells. Moreover, it was observed that MI increased apoptosis compared to untreated cells. Further investigation showed that the SUMOylation of c-Myc was enhanced by MI and led to the down-regulated protein level of c-Myc, which is involved in regulating cell proliferation and apoptosis. SENP1 has been demonstrated to be critical for the SUMOylation of c-Myc. Meanwhile, knockdown of SENP1 by siRNA abolished the effects of MI on c-Myc level and cell viability in colon cancer cells. Together, these results revealed that MI exerted an anti-tumor activity in colon cancer cells via SENP1/c-Myc signaling pathway. These finding provide an insight into the potential of MI for colon cancer therapy.

Discovery and Synthesis of a Pyrimidine-Based Aurora Kinase Inhibitor to Reduce Levels of MYC Oncoproteins.

The A-type Aurora kinase is upregulated in many human cancers, and it stabilizes MYC-family oncoproteins, which have long been considered an undruggable target. Here, we describe the design and synthesis of a series of pyrimidine-based derivatives able to inhibit Aurora A kinase activity and reduce levels of cMYC and MYCN. Through structure-based drug design of a small molecule that induces the DFG-out conformation of Aurora A kinase, lead compound 13 was identified, which potently (IC50 < 200 nM) inhibited the proliferation of high-MYC expressing small-cell lung cancer (SCLC) cell lines. Pharmacokinetic optimization of 13 by prodrug strategies resulted in orally bioavailable 25, which demonstrated an 8-fold higher oral AUC (F = 62.3%). Pharmacodynamic studies of 25 showed it to effectively reduce cMYC protein levels, leading to >80% tumor regression of NCI-H446 SCLC xenograft tumors in mice. These results support the potential of 25 for the treatment of MYC-amplified cancers including SCLC.

Targeting Dietary and Microbial Tryptophan-Indole Metabolism as Therapeutic Approaches to Colon Cancer.

Tryptophan metabolism, via the kynurenine (Kyn) pathway, and microbial transformation of tryptophan to indolic compounds are fundamental for host health; both of which are altered in colon carcinogenesis. Alterations in tryptophan metabolism begin early in colon carcinogenesis as an adaptive mechanism for the tumor to escape immune surveillance and metastasize. The microbial community is a key part of the tumor microenvironment and influences cancer initiation, promotion and treatment response. A growing awareness of the impact of the microbiome on tryptophan (Trp) metabolism in the context of carcinogenesis has prompted this review. We first compare the different metabolic pathways of Trp under normal cellular physiology to colon carcinogenesis, in both the host cells and the microbiome. Second, we review how the microbiome, specifically indoles, influence host tryptophan pathways under normal and oncogenic metabolism. We conclude by proposing several dietary, microbial and drug therapeutic modalities that can be utilized in combination to abrogate tumorigenesis.

Valtrate as a novel therapeutic agent exhibits potent anti-pancreatic cancer activity by inhibiting Stat3 signaling.

BACKGROUND: Valtrate is a novel epoxy iridoid ester isolated from Chinese herbal medicine Valeriana jatamansi Jones with anti-proliferative activity against various human cancer cell lines. However, its efficacy and molecular mechanisms against pancreatic cancer (PC) cells are largely unclear. PURPOSE: To investigate the anti-cancer effects of valtrate on PC cell lines and its underlying mechanisms. METHODS: MTT assay was first performed to detect the effect of valtrate on cell viability in human PC cell lines and normal pancreatic epithelial cells HPDE. Cell apoptosis and cycle phase assay were detected by flow cytometry. The relative mRNA expressions of Bax, Bcl-2, c-Myc, and CyclinB1 were tested by quantitative PCR (qPCR) assay. The expression of relative proteins was detected by Western blotting (WB). A PANC-1luc cells xenograft mouse model in nu/nu female mice was used to elucidate the effect of valtrate on tumor growth in vivo. RESULTS: Valtrate significantly inhibited the growth of PC cells without affecting the growth of normal pancreatic epithelial cells HPDE, induced significant apoptosis and cell cycle arrest in G2/M phase. Moreover, valtrate inhibited the tumor growth of PC cell PANC-1 in xenograft mice by 61%. Further mechanism study demonstrated that valtrate could increase the expression level of Bax, suppress Bcl-2 as well as c-Myc and Cyclin B1, inhibit the transcriptional activity of Stat3, while valtrate decreased the expression level of Stat3 and phosphated-Stat3 (Tyr705) and induced the high molecular aggregation of Stat3. Molecular docking analysis predicted that valtrate might interact with Cys712 of Stat3 protein. Valtrate could also induce a transient depleted intracellular glutathione (GSH) level and increased reactive oxygen species (ROS). NAC (N-acetylcysteine), a reducer reversed valtrate-induced the depletion of Stat3, p-Stat3, c-Myc, and Cyclin B1. CONCLUSION: Valtrate exerts anti-cancer activity against PC cells by directly targeting Stat3 through a covalent linkage to inhibit Stat3 activity, which causes apoptosis and cell cycle arrest.