Antagonizing roles of SHP1 in the pathogenesis of Helicobacter pylori infection.

BACKGROUND: SHP1 has been documented as a tumor suppressor and it was thought to play an antagonistic role in the pathogenesis of Helicobacter pylori infection. In this study, the exact mechanism of this antagonistic action was studied. MATERIALS AND METHODS: AGS, MGC803, and GES-1 cells were infected with H. pylori, intracellular distribution changes of SHP1 were first detected by immunofluorescence. SHP1 overexpression and knockdown were then constructed in these cells to investigate its antagonistic roles in H. pylori infection. Migration and invasion of infected cells were detected by transwell assay, secretion of IL-8 was examined via ELISA, the cells with hummingbird-like alteration were determined by microexamination, and activation of JAK2/STAT3, PI3K/Akt, and ERK pathways were detected by immunoblotting. Mice infection model was established and gastric pathological changes were evaluated. Finally, the SHP1 activator sorafenib was used to analyze the attenuating effect of SHP1 activation on H. pylori pathogenesis in vitro and in vivo. RESULTS: The sub-localization of SHP1 changed after H. pylori infection, specifically that the majority of the cytoplasmic SHP1 was transferred to the cell membrane. SHP1 inhibited H. pylori-induced activation of JAK2/STAT3 pathway, PI3K/Akt pathway, nuclear translocation of NF-κB, and then reduced EMT, migration, invasion, and IL-8 secretion. In addition, SHP1 inhibited the formation of CagA-SHP2 complex by dephosphorylating phosphorylated CagA, reduced ERK phosphorylation and the formation of CagA-dependent hummingbird-like cells. In the mice infection model, gastric pathological changes were observed and increased IL-8 secretion, indicators of cell proliferation and EMT progression were also detected. By activating SHP1 with sorafenib, a significant curative effect against H. pylori infection was obtained in vitro and in vivo. CONCLUSIONS: SHP1 plays an antagonistic role in H. pylori pathogenesis by inhibiting JAK2/STAT3 and PI3K/Akt pathways, NF-κB nuclear translocation, and CagA phosphorylation, thereby reducing cell EMT, migration, invasion, IL-8 secretion, and hummingbird-like changes.

Low-Dose Sorafenib Promotes Cancer Stem Cell Expansion and Accelerated Tumor Progression in Soft Tissue Sarcomas.

The cancer stem cell (CSC) hypothesis postulates that heterogeneous human cancers harbor a population of stem-like cells which are resistant to cytotoxic therapies, thus providing a reservoir of relapse following conventional therapies like chemotherapy and radiation (RT). CSCs have been observed in multiple human cancers, and their presence has been correlated with worse clinical outcomes. Here, we sought to evaluate the impact of drug dosing of the multi-tyrosine kinase inhibitor, sorafenib, on CSC and non-CSCs in soft tissue sarcoma (STS) models, hypothesizing differential effects of sorafenib based on dose and target cell population. In vitro, human cancer cell lines and primary STS from surgical specimens were exposed to escalating doses of sorafenib to determine cell viability and expression of CSC marker aldehyde dehydrogenase (ALDH). In vivo, ALDHbright CSCs were isolated, exposed to sorafenib, and xenograft growth and survival analyses were performed. We observed that sarcoma CSCs appear to paradoxically respond to the tyrosine kinase inhibitor sorafenib at low doses with increased proliferation and stem-like function of CSCs, whereas anti-viability effects dominated at higher doses. Importantly, STS patients receiving neoadjuvant sorafenib and RT on a clinical trial (NCT00864032) showed increased CSCs post therapy, and higher ALDH scores post therapy were associated with worse metastasis-free survival. These data suggest that low-dose sorafenib may promote the CSC phenotype in STS with clinically significant effects, including increased tumor growth and higher rates of metastasis formation in sarcoma patients.

Three tyrosine kinase inhibitors cause cardiotoxicity by inducing endoplasmic reticulum stress and inflammation in cardiomyocytes.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) are anti-cancer therapeutics often prescribed for long-term treatment. Many of these treatments cause cardiotoxicity with limited cure. We aim to clarify molecular mechanisms of TKI-induced cardiotoxicity so as to find potential targets for treating the adverse cardiac complications. METHODS: Eight TKIs with different levels of cardiotoxicity reported are selected. Phenotypic and transcriptomic responses of human cardiomyocytes to TKIs at varying doses and times are profiled and analyzed. Stress responses and signaling pathways that modulate cardiotoxicity induced by three TKIs are validated in cardiomyocytes and rat hearts. RESULTS: Toxicity rank of the eight TKIs determined by measuring their effects on cell viability, contractility, and respiration is largely consistent with that derived from database or literature, indicating that human cardiomyocytes are a good cellular model for studying cardiotoxicity. When transcriptomes are measured for selected TKI treatments with different levels of toxicity in human cardiomyocytes, the data are classified into 7 clusters with mainly single-drug clusters. Drug-specific effects on the transcriptome dominate over dose-, time- or toxicity-dependent effects. Two clusters with three TKIs (afatinib, ponatinib, and sorafenib) have the top enriched pathway as the endoplasmic reticulum stress (ERS). All three TKIs induce ERS in rat primary cardiomyocytes and ponatinib activates the IRE1α-XBP1s axis downstream of ERS in the hearts of rats underwent a 7-day course of drug treatment. To look for potential triggers of ERS, we find that the three TKIs induce transient reactive oxygen species followed by lipid peroxidation. Inhibiting either PERK or IRE1α downstream of ERS blocks TKI-induced cardiac damages, represented by the induction of cardiac fetal and pro-inflammatory genes without causing more cell death. CONCLUSIONS: Our data contain rich information about phenotypic and transcriptional responses of human cardiomyocytes to eight TKIs, uncovering potential molecular mechanisms in modulating cardiotoxicity. ER stress is activated by multiple TKIs and leads to cardiotoxicity through promoting expression of pro-inflammatory factors and cardiac fetal genes. ER stress-induced inflammation is a promising therapeutic target to mitigate ponatinib- and sorafenib-induced cardiotoxicity.

Binding of berberine to PEBP1 synergizes with sorafenib to induce the ferroptosis of hepatic stellate cells.

Hepatic stellate cell (HSC) activation is the key process in hepatic fibrosis (HF) development. Targeted death of HSCs could be effective in the prevention and treatment of HF. Phosphatidylethanolamine-binding protein (PEBP)1 can trigger ferroptosis by mediating peroxide production, but how it modulates HSC ferroptosis is not known. We screened natural small molecules that could bind with PEBP1, and investigated the mechanism by which it promotes HSC ferroptosis. The maximum binding energy of berberine with PEBP1 was - 8.51 kcal/mol, indicating that berberine could bind strongly with PEBP1. Berberine binding to PEBP1 could promote HSC ferroptosis via synergy of its actions with those of sorafenib, but it could not induce ferroptosis alone. Combined administration of berberine enhanced the ferroptotic effects of low-dose sorafenib upon HSCs. Herein, we revealed that PEBP1 might be a target that could enhance the effects of sorafenib, which could provide a new therapeutic approach for HF treatment.

Crithmum maritimum Improves Sorafenib Sensitivity by Decreasing Lactic Acid Fermentation and Inducing a Pro-Hepatocyte Marker Profile in Hepatocellular Carcinoma.

Edible plants are gaining importance as an integrative therapy for many chronic diseases, including cancer. We first reported that the edible wild plant Crithmum maritimum L. inhibits the growth of hepatocellular carcinoma (HCC) cells by exerting a multitarget action on cellular metabolism and bioenergetic profile. Here, we show that Crithmum maritimum ethyl acetate extract significantly increases the responsiveness of HCC cells to the chemotherapeutic drug sorafenib by reducing lactic acid fermentation and inducing a pro-hepatocyte biomarker profile. Our findings strengthen the role of Crithmum maritimum L. as a valuable nutraceutical tool to support pharmacological therapeutic interventions in HCC.

Sorafenib induces pigmentation via the regulation of ß-catenin signalling pathway in melanoma cells.

We conducted large-scale screening test on drugs that were already approved for other diseases to find pigmentation-modulating agents. Among drugs with potential for pigmentation control, we selected sorafenib and further investigated the effect on pigmentation using HM3KO melanoma cells. As a result of treating melanoma cells with sorafenib, pigmentation was promoted in terms of melanin content and tyrosinase activity. Sorafenib increased mRNA and protein levels of pigmentation-related genes such as MITF, tyrosinase and TRP1. To uncover the action mechanism, we investigated the effect of sorafenib on the intracellular signalling pathways. Sorafenib reduced phosphorylation of AKT and ERK, suggesting that sorafenib induces pigmentation through inhibition of the AKT and ERK pathways. In addition, sorafenib significantly increased the level of active ß-catenin, together with activation of ß-catenin signalling. Mechanistic study revealed that sorafenib decreased phosphorylation of serine 9 (S9) of GSK3ß, while it increased phosphorylation of tyrosine 216 (Y216) of GSK3ß. These results suggest that sorafenib activates the ß-catenin signalling through the regulation of GSK3ß phosphorylation, thereby affecting the pigmentation process.

Fibrinogen-Like Protein 1 Modulates Sorafenib Resistance in Human Hepatocellular Carcinoma Cells.

Despite liver cancer being the second-leading cause of cancer-related death worldwide, few systemic drugs have been approved. Sorafenib, the first FDA-approved systemic drug for unresectable hepatocellular carcinoma (HCC), is limited by resistance. However, the precise mechanisms underlying this phenomenon are unknown. Since fibrinogen-like 1 (FGL1) is involved in HCC progression and upregulated after anticancer therapy, we investigated its role in regulating sorafenib resistance in HCC. FGL1 expression was assessed in six HCC cell lines (HepG2, Huh7, Hep3B, SNU387, SNU449, and SNU475) using western blotting. Correlations between FGL1 expression and sorafenib resistance were examined by cell viability, colony formation, and flow cytometry assays. FGL1 was knocked-down to confirm its effects on sorafenib resistance. FGL1 expression was higher in HepG2, Huh7, and Hep3B cells than in SNU387, SNU449, and SNU475 cells; high FGL1-expressing HCC cells showed a lower IC50 and higher sensitivity to sorafenib. In Huh7 and Hep3B cells, FGL1 knockdown significantly increased colony formation by 61% (p = 0.0013) and 99% (p = 0.0002), respectively, compared to that in controls and abolished sorafenib-induced suppression of colony formation, possibly by modulating ERK and autophagy signals. Our findings demonstrate that sorafenib resistance mediated by FGL1 in HCC cells, suggesting FGL1 as a potential sorafenib-resistance biomarker and target for HCC therapy.

Apolipoprotein E Peptide-Guided Disulfide-Cross-Linked Micelles for Targeted Delivery of Sorafenib to Hepatocellular Carcinoma.

Sorafenib (SF) is an FDA-approved molecular-targeted drug for treating hepatocellular carcinoma (HCC). SF, however, suffers from poor water solubility, low bioavailability, dose-limiting side effects, and possible drug resistance. Here, we report on apolipoprotein E peptide-decorated disulfide-cross-linked micellar SF (ApoE-Ms-SF) as a targeted and intelligent formulation for HCC therapy. ApoE-Ms-SF was prepared with a good SF loading of 7.0 wt %, small size (37 nm), high stability, and reduction-triggered drug release from poly(ethylene glycol)-b-poly(ε-caprolactone-co-dithiolane trimethylene carbonate)-mefenamate (PEG-P(CL-DTC)-MA) and ApoE-modified ApoE-PEG-P(CL-DTC) block copolymers. MTT assays in low-density lipoprotein receptors (LDLRs) overexpressing SMMC-7721 human liver cancer cells showed ApoE density-dependent antitumor potency of ApoE-Ms-SF, in which 7.5% ApoE led to the best antitumor effect (IC50: 8.5 vs 23.3 µg/mL for free SF). Confocal studies, flow cytometry, western blot, and apoptotic assays illustrated clearly a more efficient uptake of ApoE-Ms than nontargeted Ms by SMMC-7721 cells as well as lower phosphorylated extracellular signal-regulated kinase protein level and better cell apoptosis caused by ApoE-Ms-SF compared with Ms-SF and free SF. ApoE-Ms-SF revealed a long circulation time (elimination half-life = 6.8 h). DiR-loaded ApoE-Ms showed a significantly higher accumulation in SMMC-7721 tumor than the nontargeted counterpart. The therapeutic outcomes in the orthotopic SMMC-7721 tumor models demonstrated that ApoE-Ms-SF reduced SF-associated side effects and brought about enhanced angiogenesis inhibition and tumor apoptosis compared to free SF and Ms-SF controls, leading to a better treatment of HCC.

3D-QSAR pharmacophore modelling, virtual screening and docking studies for lead discovery of a novel scaffold for VEGFR 2 inhibitors: Design, synthesis and biological evaluation.

A series of novel 6,7-dihydro-5H-cyclopenta[d]pyrimidine derivatives was successfully designed, synthesized and evaluated as a new chemical scaffold with vascular endothelial growth factor receptor (VEGFR 2) inhibitory activity. Compounds 6c and 6b showed enzyme inhibition of 97% and 87% at 10 µM, respectively, and exhibited potent dose-related VEGFR 2 inhibition with IC50 values of 0.85 µM and 2.26 µM, respectively. The design of the 6,7-dihydro-5H-cyclopenta[d]pyrimidine scaffold was implemented via consecutive molecular modelling protocols prior to the synthesis and biological evaluation of the derivatives. First, sorafenib was docked in the binding site of VEGFR 2 to study its binding orientation and affinity, followed by the generation of a valid 3D QSAR pharmacophore model for use in the virtual screening of different 3D databases. Structures with promising pharmacophore-based virtual screening results were refined using molecular docking studies in the binding site of VEGFR 2. A novel scaffold was designed by incorporating the results of the pharmacophore model generation and molecular docking studies. The new scaffold showed hydrophobic interactions with the kinase front pocket that may be attributed to increasing residence time in VEGFR 2, which is a key success factor for ligand optimization in drug discovery. Different derivatives of the novel scaffold were validated using docking studies and pharmacophore mapping, where they exhibited promising results as VEGFR 2 inhibitors to be synthesized and biologically evaluated. 6,7-dihydro-5H-cyclopenta[d]pyrimidine is a new scaffold that can be further optimized for the synthesis of promising VEGFR 2 inhibitors.

Celastrol Enhances the Anti-Liver Cancer Activity of Sorafenib.

BACKGROUND Sorafenib, a multiple-target-point kinase inhibitor, has been used as a standard treatment for advanced liver cancer and has shown therapeutic benefits. However, resistance often occurs, prompting the need for identification of synergizing agents. Celastrol is a major active ingredient of Tripterygium wilfordii, which can increase the antitumor effect of traditional antitumor drugs. This work focused on the sensitization of liver cancers in use of celastrol combined with sorafenib. MATERIAL AND METHODS The IC50 values of sorafenib and celastrol on cancer cells were determined through MTT assays. The effects of sorafenib on AKT signaling and VEGF levels in sorafenib-treated cancer cells were analyzed by Western blotting and ELISA, respectively. After combined treatment with celastrol and sorafenib, the survival rate of tumor cells was determined by MTT and clonogenic assays, and the apoptosis rate was also determined by flow cytometry. In addition, the in vivo antitumor activity of celastrol combined with sorafenib was evaluated in Hepa1-6 tumor-bearing mice. RESULTS Sorafenib treatment induced the compensatory activation of the AKT pathway and autocrine VEGF in hepatoma cells, which could be reversed by celastrol. Furthermore, celastrol enhanced the growth inhibition and apoptosis induction of cancer cells by sorafenib both in vitro and in vivo and reduced the dosage of sorafenib needed. CONCLUSIONS Celastrol enhances the antitumor activity of sorafenib in HCC tumor cells by suppressing the AKT pathway and VEGF autocrine system.

Antiviral mechanisms of sorafenib against foot-and-mouth disease virus via c-RAF and AKT/PI3K pathways.

Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen that poses a significant threat to the global livestock industry. However, specific antiviral treatments against FMDV are currently unavailable. This study aimed to evaluate the antiviral activity of anticancer drugs, including kinase and non-kinase inhibitors against FMDV replication in BHK-21 cells. Sorafenib, a multi-kinase inhibitor, demonstrated a significant dose-dependent reduction in FMDV replication. It exhibited a half maximal effective concentration (EC50) value of 2.46 µM at the pre-viral entry stage and 2.03 µM at the post-viral entry stage. Further intracellular assays revealed that sorafenib effectively decreased 3Dpol activity with a half maximal inhibitory concentration (IC50) of 155 nM, while not affecting 3Cpro function. The study indicates that sorafenib influences host protein pathways during FMDV infection, primarily by potentiating the c-RAF canonical pathway and AKT/PI3K pathway. Molecular docking analysis demonstrated specific binding of sorafenib to the active site of FMDV 3Dpol, interacting with crucial catalytic residues, including D245, D338, S298, and N307. Additionally, sorafenib exhibited significant binding affinity to the active site motifs of cellular kinases, namely c-RAF, AKT, and PI3K, which play critical roles in the viral life cycle. The findings suggest that sorafenib holds promise as a therapeutic agent against FMDV infection. Its mechanism of action may involve inhibiting FMDV replication by reducing 3Dpol activity and regulating cellular kinases. This study provides insights for the development of novel therapeutic strategies to combat FMDV infections.

The effects of sorafenib in healthy and cisplatin-treated rats.

BACKGROUND: Sorafenib is a multikinase inhibitor currently used in the treatment of hepatocellular carcinoma, renal cell carcinoma and thyroid cancer. OBJECTIVES: The literature on this agent is scarce. This study aimed to evaluate the effects of sorafenib when administered to both healthy and cisplatin-induced rats. MATERIAL AND METHODS: The animals were divided into 4 groups: 1) control group that received 0.9% saline intraperitoneally (C); 2) group administered a single dose (7 mg/kg) of cisplatin (Cis); 3) a group administered 20 mg/kg of sorafenib for 7 days (Sor); 4) group administered 20 mg/kg of sorafenib followed by 7 mg/kg of cisplatin for 7 days (Cis+Sor). All animals were sacrificed 7 days after the completion of their treatment arm, and serum and tissue samples were taken. RESULTS: Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and interleukin 38 (IL-38) levels were increased in the Sor and Cis+Sor groups compared to the control group. When compared with the control group, serum urea, creatinine, kidney IL-1ß, and tumor necrosis factor alpha (TNF-α) levels did not change in the Sor group. When compared to the Cis group, the levels of these parameters decreased in the Cis+Sor group. CONCLUSIONS: According to the data obtained, sorafenib caused liver toxicity when given to both healthy and cisplatin-induced rats. While sorafenib did not cause any significant changes in the kidneys when given to healthy rats, it had a healing effect in kidneys after stress induced by cisplatin.

Targeting the Lysosomal Degradation of Rab22a-NeoF1 Fusion Protein for Osteosarcoma Lung Metastasis.

Rab22a-NeoF fusion protein has recently been reported as a promising target for osteosarcoma lung metastasis. However, how this fusion protein is regulated in cells remains unknown. Here, using multiple screenings, it is reported that Rab22a-NeoF1 fusion protein is degraded by an E3 ligase STUB1 via the autophagy receptor NDP52-mediated lysosome pathway, which is facilitated by PINK1 kinase. Mechanistically, STUB1 catalyzes the K63-linked ubiquitin chains on lysine112 of Rab22a-NeoF1, which is responsible for the binding of Rab22a-NeoF1 to NDP52, resulting in lysosomal degradation of Rab22a-NeoF1. PINK1 is able to phosphorylate Rab22a-NeoF1 at serine120, which promotes ubiquitination and degradation of Rab22a-NeoF1. Consistently, by upregulating PINK1, Sorafenib and Regorafenib can inhibit osteosarcoma lung metastasis induced by Rab22a-NeoF1. These findings reveal that the lysosomal degradation of Rab22a-NeoF1 fusion protein is targetable for osteosarcoma lung metastasis, proposing that Sorafenib and Regorafenib may benefit cancer patients who are positive for the RAB22A-NeoF1 fusion gene.

Astaxanthin Supplementation Assists Sorafenib in Slowing Skeletal Muscle Atrophy in H22 Tumor-Bearing Mice via Reversing Abnormal Glucose Metabolism.

SCOPE: Cachexia, which is often marked by skeletal muscular atrophy, is one of the leading causes of death in cancer patients. Astaxanthin, a carotenoid obtained from marine organisms that can aid in the prevention and treatment of a variety of disorders. In this study, to assess whether astaxanthin ameliorates weight loss and skeletal muscle atrophy in sorafenib-treated hepatocellular carcinoma mice is aimed. METHODS AND RESULTS: H22 mice are treated with 30 mg kg-1  day-1 of sorafenib and 60 mg kg-1  day-1 of astaxanthin by gavage lasted for 18 days. Sorafenib does not delay skeletal muscle atrophy and weight loss, although it does not reduce tumor burden. Astaxanthin dramatically delays weight loss and skeletal muscle atrophy in sorafenib-treating mice, without affecting the food intake. Astaxanthin inhibits the tumor glycolysis, slows down gluconeogenesis, and improves insulin resistance in tumor-bearing mice. Astaxanthin increases glucose competition in skeletal muscle by targeting the PI3K/Akt/GLUT4 signaling pathway, and enhances glucose utilization efficiency in skeletal muscle, thereby slowing skeletal muscle atrophy. CONCLUSION: The findings show the significant potential of astaxanthin as nutritional supplements for cancer patients, as well as the notion that nutritional interventions should be implemented at the initiation of cancer treatment, as instead of waiting until cachexia sets in.

Cytochrome P450 3A5 polymorphism affects the metabolism of sorafenib and its toxicity for hepatocellular carcinoma cells in vitro.

OBJECTIVE: Cytochrome P450 3A5 (CYP3A5) is a highly polymorphic gene and the encoded protein variants differ in catalytic activity, leading to inter-individual variation in metabolic ability. The aim of the current study was to investigate the effects of seven allelic variants on the ability of CYP3A5 to metabolize sorafenib in vitro and further explore the impacts of CYP3A5 polymorphism on the proliferation and apoptosis of hepatocellular carcinoma cell line (HepG2) induced by sorafenib. METHODS: Wild-type and variant CYP3A5 enzymes were expressed in Spodoptera frugiperda insect cells using a baculovirus dual-expression system, and protein expression was checked by western blot. The enzymes were incubated with sorafenib at 37°C for 30 min, and formation of the major metabolite sorafenib N-oxide was assayed using ultra-performance liquid chromatography and tandem mass spectrometry. Intrinsic clearance values (Vmax/Km) were calculated for each enzyme. Additionally, recombinant HepG2 cells transfecting with CYP3A5 variants were used to investigate the effects of sorafenib on the proliferation of HepG2 cells. RESULTS: Intrinsic clearance of the six variants CYP3A5*2, CYP3A5*3A, CYP3A5*3C, CYP3A5*4, CYP3A5*5, and CYP3A5*7 was 26.41-71.04% of the wild-type (CYP3A5*1) value. In contrast, the clearance value of the variant CYP3A5*6 was significantly higher (174.74%). Additionally, the decreased ATP levels and cell viability and the increased cell apoptosis in HepG2 cells transfected with CYP3A5*2, CYP3A5*3A, CYP3A5*3C, CYP3A5*4, CYP3A5*5, and CYP3A5*7 were observed, whereas, the increased ATP levels and cell viability and the reduced cell apoptosis in HepG2 cells transfected with CYP3A5*6 were also investigated when compared to CYP3A5*1. CONCLUSION: Our results suggest that CYP3A5 polymorphism influences sorafenib metabolism and pharmacotherapeutic effect in hepatic carcinomas. These data may help explain differential response to drug therapy for hepatocellular carcinoma, and they support the need for individualized treatment.

Impaired autophagy and mitochondrial dynamics are involved in Sorafenib-induced cardiomyocyte apoptosis.

Sorafenib (Sor), a novel multi-target anticancer drug also induces severe toxicity in heart, while the mechanism of its cardiotoxicity remains to be fully elucidated. Dysregulation of autophagy and mitochondrial dynamics imbalance have been implicated in cardiomyocyte death. The aim of this study is to test the hypothesis that Sor disrupts autophagy and mitochondrial dynamics, thereby aggravating Sor-induced oxidative stress damage to cardiomyocytes. Our results revealed that Sor (≥ 5 µM) concentration- and time-dependently reduced cell viability and induced apoptosis in H9c2 myoblasts. Sor treatment promoted intracellular reactive oxygen species (ROS) generation, and subsequent Ca2+ overload as well as apoptosis, which were abolished by the ROS scavenger MPG. Sor inhibited the basal autophagy activity of cells, as supported by the fact that ERK1/2 inhibition-dependent decreases of autophagosomes and autolysosomes, and p62 accumulation in a concentration- and time-dependent manner. Improving autophagy with rapamycin abrogated Sor-induced ROS and Ca2+ overloads, and cell apoptosis. Furthermore, Sor compromised mitochondrial morphology and caused excessive mitochondrial fragmentation in cells. The imbalance of mitochondrial dynamics was attributed to ROS-mediated CaMKII overactivity, and increased phosphorylation of dynamin-related protein 1 (phosph-Drp1). Suppression of CaMKII with KN-93 or mitochondrial fission with mitochondrial division inhibitor-1 (Mdivi-1) attenuated Sor-induced ROS and Ca2+ overloads as well as apoptosis. In conclusion, these results provide the first evidence that impairments in autophagy and mitochondrial dynamics are involved in Sor-induced cardiomyocyte apoptosis. The present study may provide a potential strategy for preventing or reducing cardiotoxicity of Sor.

Chromenopyrimidinone exhibit antitumor effects through inhibition of CAP1 (Adenylyl cyclase-associated protein 1) expression in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most malignant human cancers, with a high mortality rate worldwide. Within an HCC tumor, cancer stem cells (CSCs) are responsible for tumor maintenance and progression and may contribute to resistance to standard HCC treatments. Previously, we characterized CD133+ cells as CSCs in primary HCC and identified chromenopyrimidinone (CPO) as a novel therapeutic for the effective treatment of CD133+ HCC. However, the biological function and molecular mechanism of CD133 remain unclear. Epigenetic alterations of CSCs have impacts on tumor initiation, progression, and therapeutic response. Here, we found that pharmacological and genetic depletion of CD133 in HCC attenuated the activity of DNA methyltransferases via control of DNMT3B stabilization. Genes were ranked by degree of promoter hypo/hyper methylation and significantly differential expression to create an "epigenetically activated by CPO" ranked genes list. Through this epigenetic analysis, we found that CPO treatment altered DNA methylation-mediated oncogenic signaling in HCCs. Specifically, CPO treatment inhibited Adenylyl cyclase-associated protein 1 (CAP1) expression, thereby reducing FAK/ERK activity and EMT-related proteins in HCC. Moreover, CPO improved the efficacy of sorafenib by inhibiting CAP1 expression and FAK/ERK activation in sorafenib-resistant HCC. These novel mechanistic insights may ultimately open up avenues for strategies targeting DNA methylation in liver cancer stem cells and provides novel therapeutic function of CPO for the effective treatment of sorafenib-resistant HCC.

A Functional Screening Identifies a New Organic Selenium Compound Targeting Cancer Stem Cells: Role of c-Myc Transcription Activity Inhibition in Liver Cancer.

Cancer stem cells (CSCs) are reported to play essential roles in chemoresistance and metastasis. Pathways regulating CSC self-renewal and proliferation, such as Hedgehog, Notch, Wnt/ß-catenin, TGF-ß, and Myc, may be potential therapeutic targets. Here, a functional screening from the focused library with 365 compounds is performed by a step-by-step strategy. Among these candidate molecules, phenyl-2-pyrimidinyl ketone 4-allyl-3-amino selenourea (CU27) is chosen for further identification because it proves to be the most effective compound over others on CSC inhibition. Through ingenuity pathway analysis, it is shown CU27 may inhibit CSC through a well-known stemness-related transcription factor c-Myc. Gene set enrichment analysis, dual-luciferase reporter assays, expression levels of typical c-Myc targets, molecular docking, surface plasmon resonance, immunoprecipitation, and chromatin immunoprecipitation are conducted. These results together suggest CU27 binds c-Myc bHLH/LZ domains, inhibits c-Myc-Max complex formation, and prevents its occupancy on target gene promoters. In mouse models, CU27 significantly sensitizes sorafenib-resistant tumor to sorafenib, reduces the primary tumor size, and inhibits CSC generation, showing a dramatic anti-metastasis potential. Taken together, CU27 exerts inhibitory effects on CSC and CSC-associated traits in hepatocellular carcinoma (HCC) via c-Myc transcription activity inhibition. CU27 may be a promising therapeutic to treat sorafenib-resistant HCC.

Sorafenib targets and inhibits the oncogenic properties of endometrial cancer stem cells via the RAF/ERK pathway.

BACKGROUND: Distinct subsets of cancer stem cells (CSCs) drive the initiation and progression of malignant tumors via enhanced self-renewal and development of treatment/apoptosis resistance. Endometrial CSC-selective drugs have not been successfully developed because most endometrial cell lines do not contain a sufficient proportion of stable CSCs. Here, we aimed to identify endometrial CSC-containing cell lines and to search for endometrial CSC-selective drugs. METHODS: We first assessed the presence of CSCs by identifying side populations (SPs) in several endometrial cancer cell lines. We then characterized cell viability, colony-formation, transwell invasion and xenotransplantion capability using the isolated SP cells. We also conducted real-time RT-PCR, immunoblot and immunofluorescence analyses of the cells' expression of CSC-associated markers. Focusing on 14 putative CSC-selective drugs, we characterized their effects on the proliferation and apoptosis of endometrial cancer cell lines, examining cell viability and annexin V staining. We further examined the inhibitory effects of the selected drugs, focusing on proliferation, invasion, expression of CSC-associated markers and tumor formation. RESULTS: We focused on HHUA cells, an endometrial cancer cell line derived from a well-differentiated endometrial adenocarcinoma. HHUA cells contained a sufficient proportion of stable CSCs with an SP phenotype (HHUA-SP). HHUA-SP showed greater proliferation, colony-formation, and invasive capabilities compared with the main population of HHUA cells (HHUA-MP). HHUA-SP generated larger tumors with higher expression of proliferation-related markers, Ki67, c-MYC and phosphorylated ERK compared with HHUA-MP when transplanted into immunodeficient mice. Among the 14 candidate drugs, sorafenib, an inhibitor of RAF pathways and multiple kinase receptors, inhibited cell proliferation and invasion in both HHUA-SP and -MP, but more profoundly in HHUA-SP. In vivo treatment with sorafenib for 4 weeks reduced the weights of HHUA-SP-derived tumors and decreased the expression of Ki67, ZEB1, and RAF1. CONCLUSIONS: Our results suggest that HHUA is a useful cell line for discovery and identification of endometrial CSC-selective drugs, and that sorafenib may be an effective anti-endometrial cancer drug targeting endometrial CSCs.