naphthoquinones and Carcinoma--Hepatocellular

Topics: Aflatoxins; Animals; Carcinogens; Carcinoma, Hepatocellular; Haplorhini; Humans; Lethal Dose 50; Liver; Liver Diseases; Liver Neoplasms; Mice; Mycotoxins; Naphthoquinones; Rats; Sterigmatocystin; Trichothecenes

For patients with advanced hepatocellular carcinoma (HCC), the standard of care for many years has been sorafenib. Preliminary data have suggested that the combination of the NAD(P)H:quinone oxidoreductase 1 bioactivatable agent napabucasin plus sorafenib may improve clinical outcomes in patients with HCC. In this phase I, multicenter, uncontrolled, open-label study, we evaluated napabucasin (480 mg/day) plus sorafenib (800 mg/day) in Japanese patients with unresectable HCC.. Adults with unresectable HCC and an Eastern Cooperative Oncology Group performance status of 0 or 1 were enrolled in a 3 + 3 trial design. The occurrence of dose-limiting toxicities was assessed through 29 days from the start of napabucasin administration. Additional endpoints included safety, pharmacokinetics, and preliminary antitumor efficacy.. In the six patients who initiated treatment with napabucasin, no dose-limiting toxicities occurred. The most frequently reported adverse events were diarrhea (83.3%) and palmar-plantar erythrodysesthesia syndrome (66.7%), all of which were grade 1 or 2. The pharmacokinetic results for napabucasin were consistent with prior publications. The best overall response (per Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1) was stable disease in four patients. Using Kaplan-Meier methodology, the 6-month progression-free survival rate was 16.7% per RECIST 1.1 and 20.0% per modified RECIST for HCC. The 12-month overall survival rate was 50.0%.. These findings confirm the viability of napabucasin plus sorafenib treatment, and there were no safety or tolerability concerns in Japanese patients with unresectable HCC.. ClinicalTrials.gov identifier NCT02358395, registered on 9 February 2015.

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Benzofurans; Carcinoma, Hepatocellular; East Asian People; Humans; Liver Neoplasms; Naphthoquinones; Sorafenib

Topics: Ataxia Telangiectasia Mutated Proteins; Carcinoma, Hepatocellular; Cell Cycle Proteins; Checkpoint Kinase 2; DNA Damage; Humans; Liver Neoplasms; M Cells; Naphthoquinones; Oxidative Stress; Phosphorylation; Reactive Oxygen Species; Signal Transduction; Tumor Suppressor Protein p53

Macrophages are the most abundant immune cells in the tumor stroma, and their polarization states within the tumor microenvironment (TME) exert critical roles in tumorigenesis. TU-100 (Daikenchuto) is a commonly prescribed Japanese herbal medicine that has shown anti-cancer effects by regulating cancer-associated fibroblasts (CAFs) in the TME. However, its effects on tumor-associated macrophages (TAMs) remain unclear.. TAMs were generated by macrophage exposure to tumor-conditioned medium (CM), and their polarization states were evaluated after TU-100 treatment. The underlying mechanism was further studied.. TU-100 exhibited little cytotoxicity over a range of doses in M0 macrophages and TAMs. However, it could antagonize the M2-like polarization of macrophages evoked by tumor-CM exposure. These effects might be caused by the inhibition of TLR4/NF-B/STAT3 signaling in the M2-like phenotype of macrophages. Interestingly, TU-100 antagonized the malignancy promoting effects of M2 macrophages on hepatocellular carcinoma cell lines in vitro. Mechanistically, the administration of TU-100 restrained the high expression of MMP-2, COX-2, and VEGF in TAMs.. TU-100 may alleviate the progression of cancer by regulating the M2 polarization of macrophages within the TME, suggesting a viable therapeutic approach.

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Polarity; Humans; Macrophages; Naphthoquinones; NF-kappa B; Signal Transduction; Tumor Microenvironment

1,4-naphthoquinone and its derivatives have attracted widespread attention due to their multiple biological activities, such as induction of cancer cell apoptosis; however, most of these compounds have high cytotoxicity. In this study, in order to reduce their toxicity and increase their potential anti-tumor effects, we synthesized a novel 1,4-naphthoquinone derivative named 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone (NTDMNQ), and investigated its apoptotic effects and underlying mechanism. Our results showed that NTDMNQ inhibited the viability of HepG2, Hep3B, and Huh7 human hepatocellular carcinoma (HCC) cells. It also increased the accumulation of cells in the G0/G1 phase of the cell cycle by increasing the expression levels of p-p53, p21 and p27, while decreasing the levels of Cyclin D1, Cyclin E, Cyclin-dependent kinase 2 (CDK2), CDK4, and CDK6. Inhibition of reactive oxygen species (ROS) by the ROS scavenger N-acetyl-L-cysteine (NAC) decreased apoptosis in NTDMNQ-treated cells. Western blot analysis showed that NTDMNQ increased the phosphorylation of p38 and c-Jun N-terminal kinase (JNK), and decreased the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and signal transducer and activator of transcription-3 (STAT3); these effects were blocked by NAC. Both the JNK inhibitor (SP600125) and p38 inhibitor (SB203580) reversed the phosphorylation of STAT3, and the ERK inhibitor (FR180204) and AKT inhibitor (LY294002) reduced the expression of STAT3. Taken together, these findings suggest that NTDMNQ induces apoptosis via ROS-mediated MAPK, AKT and STAT3 signaling pathways in HepG2 cells, and may be a potent anticancer agent.

Topics: Apoptosis; Carcinoma, Hepatocellular; Hep G2 Cells; Humans; Liver Neoplasms; Naphthalenes; Naphthoquinones; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction; STAT3 Transcription Factor

Shikonin(SK) is a natural small molecule naphthoquinone compound, which has anti-cancer activity in various human malignant tumors. Pyrroline-5-carboxylate reductase 1(PYCR1) is involved in tumorigenesis and regulates various cellular processes, including growth, invasion, migration, and apoptosis. However, the effect of SK and PYCR1 on apoptosis and autophagy in hepatocellular carcinoma are unclear. Our goal is to determine the internal molecular mechanism of the interaction between SK and PYCR1 and its role in the occurrence and development of liver cancer. The CCK8 assay, wound healing assay, and transwell assays show that SK and siPYCR1(gene silence PYCR1) inhibited the malignant phenotype of HCC cells, including cell viability, colony formation, migration, and invasion, respectively. The flow cytometry assays and immunofluorescence show that SK and siPYCR1 activated apoptosis and autophagy, respectively. SK induces apoptosis and autophagy in a dose-dependent manner. In addition, HCC cells were transfected with small interference fragment PYCR1 siRNA to construct siPYCR1 and SK single treatment group and co-treatment group to verify the interaction between SK and PYCR1. The Western blot identified that PI3K/Akt/mTOR signal pathway protein expression was significantly downregulated in HCC cells treated with SK and siPYCR1 together. Collectively, SK may induce apoptosis and autophagy by reducing the expression of PYCR1 and suppressing PI3K/Akt/mTOR. Thus, SK may be a promising antineoplastic drug in Hepatocellular carcinoma (HCC). SK downregulating PYCR1 might supply a theoretical foundation for the potential therapeutic application in hepatocellular carcinoma.

Topics: Apoptosis; Autophagy; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Humans; Liver Neoplasms; Naphthoquinones; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyrroles; Pyrroline Carboxylate Reductases; TOR Serine-Threonine Kinases

Hepatocellular carcinoma (HCC) is resistant to current immunotherapy. This poor outcome mainly results from the immunosuppressive characteristics of tumor microenvironment (TME). Accumulating evidence indicates that some chemotherapy agents trigger immunogenic cell death (ICD), providing a promising strategy to remodel the immunosuppressive TME. The role of Plumbagin (PLB, a naphthoquinone compound from Plumbago zeylanica L.) as the ICD inducer for HCC cells was confirmed in this study. Dihydrotanshinone I (DIH, a phenanthraquinone compound of Salvia miltiorrhiza) functioned as the ICD enhancer by generating the reactive oxygen species (ROS). A poly(D,L-lactic-co-glycolic acid) (PLGA)-based nanoparticle (NP) was used to co-encapsulate PLB, DIH and NH

Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Line, Tumor; Furans; Lactic Acid; Liver Neoplasms; Mice; Nanoparticles; Naphthoquinones; Phenanthrenes; Quinones; Tumor Microenvironment

It was previously shown that the antitumor and cytotoxic activity of the essential oil (EO) extracted from the aerial parts of

Topics: Antineoplastic Agents; Boraginaceae; Carcinoma, Hepatocellular; DNA Topoisomerases, Type II; Etoposide; Humans; Leukemia, Myeloid, Acute; Liver Neoplasms; Naphthoquinones; Oils, Volatile; Reactive Oxygen Species; Topoisomerase II Inhibitors

Inhibition of tumor metastasis is a useful strategy to improve the efficacy of cancer therapy. Ventilagolin, a natural 1, 4-naphthoquinone derivative extracted from. The effects of Ventilagolin on migration, invasion, Pim-1 and EMT-related proteins (eg, E-cadherin, N-cadherin, Vimentin) expression were assessed by scratch wound healing, Transwell, qRT-PCR and Western blot assays, respectively. Pim-1 stably overexpressed HepG2 and SMMC-7721 cells were generated to explore whether Ventilagolin inhibited migration, invasion and EMT of HCC cells via regulating Pim-1. Subcutaneous xenograft tumor model in nude mice was established. Histopathological changes of tumor tissues were examined by H&E staining and expressions of Pim-1 and EMT-related proteins were detected by immunohistochemistry.. Ventilagolin significantly (. Ventilagolin suppresses HCC cell proliferation, migration and invasion and reverses EMT process by downregulating Pim-1, suggesting Ventilagolin is a potential therapeutic agent for treatment of HCC.

Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Dose-Response Relationship, Drug; Down-Regulation; Drug Screening Assays, Antitumor; Epithelial-Mesenchymal Transition; Female; Humans; Liver Neoplasms; Liver Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Structure; Naphthoquinones; Proto-Oncogene Proteins c-pim-1; RNA, Messenger; Structure-Activity Relationship; Tumor Cells, Cultured; Wound Healing

TP53 mutation is one of the most common genetic changes in hepatocellular carcinoma (HCC). It is of great clinical significance to tailor specialized prognostication approach and to explore more therapeutic options for TP53-mutant HCCs. In this study, a total of 1135 HCC patients were retrospectively analyzed. We developed a random forest-based prediction model to estimate TP53 mutational status, tackling the problem of limited sample size in TP53-mutant HCCs. A multi-step process was performed to develop robust poor prognosis-associated signature (PPS). Compared with previous established population-based signatures, PPS manifested superior ability to predict survival in TP53-mutant patients. After in silico screening of 2249 drug targets and 1770 compounds, we found that three targets (CANT1, CBFB and PKM) and two agents (irinotecan and YM-155) might have potential therapeutic implications in high-PPS patients. The results of drug targets prediction and compounds prediction complemented each other, presenting a comprehensive view of potential treatment strategy. Overall, our study has not only provided new insights into personalized prognostication approaches, but also thrown light on integrating tailored risk stratification with precision therapy.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Hepatocellular; Computer Simulation; Disease-Free Survival; Female; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Irinotecan; Liver Neoplasms; Male; Mutation; Naphthoquinones; Precision Medicine; Survival Rate; Tumor Suppressor Protein p53

In tumor cells, shikonin treatment has been reported to inhibit glycolysis by suppressing the activity of pyruvate kinase M2 (PKM2) and to induce apoptosis by increasing reactive oxygen species (ROS) production. However, hepatocellular carcinoma (HCC) shows variable sensitivity to shikonin treatment, and the mechanism for these differences remains unclear. We evaluated the effects of shikonin on metabolic and oxidative pathways in sensitive and refractory HCC cell lines to identify mechanisms of differential sensitivity.. The sensitivity to shikonin treatment was significantly higher for HepG2 cells than for HCCLM3 cells, with less dramatic effects in HCCLM3 cells on apoptosis, ROS, and oxidative phosphorylation. Shikonin up-regulated mitochondrial biogenesis to increase mitochondrial oxidative phosphorylation in HepG2 cells, but displayed the opposite trend in HCCLM3 cells. Mechanistically, shikonin promoted nuclear expression of PKM2 and HIF1α in HCCLM3 cells, with upregulation of glycolysis-related gene transcription and glycolysis.. These results suggest that PKM2 rewires glucose metabolism, which explains the differential sensitivity to shikonin-induced apoptosis in HCC cells. Our findings elucidate mechanisms for differential responses to shikonin, provide potential biomarkers, and indicate a theoretical basis for targeting glycolytic enzymes in refractory HCC.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Carcinoma, Hepatocellular; Carrier Proteins; Dose-Response Relationship, Drug; Glucose; Glycolysis; Hep G2 Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Liver Neoplasms; Membrane Proteins; Naphthoquinones; Thyroid Hormone-Binding Proteins; Thyroid Hormones

The role and significance of liver-derived cytokines in cancer-associated cachexia syndrome remain elusive. Here we report that combinatorial counterbalances of the leptin and Igf1 signaling pathways in hepatocellular carcinoma (HCC) models significantly relieves cachexia. Double transgenic zebrafish models of HCC that stably displayed focal lesions, anorexia, and wasting of adipose and muscle tissues were first generated. Knockout of lepr or mc4r from these zebrafish partially restored appetite and exerted moderate or no effect on tissue wasting. However, genetic replenishment of Igf1 in a lepr-mutant background effectively relieved the cachexia-like phenotype without affecting tumor growth. Similarly, administration of napabucasin, a Stat3/Socs3 inhibitor, on the zebrafish HCC model, mammalian cell lines with exogenous IGF1, and two mouse xenograft models restored insulin sensitivity and rescued the wasting of nontumor tissues. Together, these results describe the synergistic impact of leptin and Igf1 normalization in treating certain HCC-associated cachexia as a practical strategy. SIGNIFICANCE: Disruption of leptin signaling with normalized Igf1 expression significantly rescues anorexia, muscle wasting, and adipose wasting in Ras- and Myc-driven zebrafish models of HCC.

Topics: 3T3-L1 Cells; Adipose Tissue; Animals; Animals, Genetically Modified; Benzofurans; Cachexia; Carcinoma, Hepatocellular; Cells, Cultured; Cytokines; Disease Models, Animal; Drug Synergism; HEK293 Cells; Hep G2 Cells; Humans; Insulin Resistance; Insulin-Like Growth Factor I; Leptin; Liver; Liver Neoplasms; Mice; Muscular Atrophy; Naphthoquinones; Receptors, Leptin; Signal Transduction; Wasting Syndrome; Xenograft Model Antitumor Assays; Zebrafish

Necroptosis is an alternative form of programmed cell death that generally occurs under apoptosis-deficient conditions. Our previous work showed that connexin32 (Cx32) promotes the malignant progress of hepatocellular carcinoma (HCC) by enhancing the ability of resisting apoptosis in vivo and in vitro. Whether triggering necroptosis is a promising strategy to eliminate the apoptosis-resistant HCC cells with high Cx32 expression remains unknown. In this study, we found that Cx32 expression was positively correlated with the expression of necroptosis protein biomarkers in human HCC specimens, cell lines, and a xenograft model. Treatment with shikonin, a well-used necroptosis inducer, markedly caused necroptosis in HCC cells. Interestingly, overexpressed Cx32 exacerbated shikonin-induced necroptosis, but downregulation of Cx32 alleviated necroptosis in vitro and in vivo. Mechanistically, Cx32 was found to bind to Src and promote Src-mediated caspase 8 phosphorylation and inactivation, which ultimately reduced the activated caspase 8-mediated proteolysis of receptor-interacting serine-threonine protein kinase 1/3, the key molecule for necroptosis activation. In conclusion, we showed that Cx32 contributed to the activation of necroptosis in HCC cells through binding to Src and then mediating the inactivation of caspase 8. The present study suggested that necroptosis inducers could be more favorable than apoptosis inducers to eliminate HCC cells with high expression of Cx32.

Topics: Animals; Apoptosis; Carcinoma, Hepatocellular; Caspase 8; Cell Line, Tumor; Cell Proliferation; Connexins; Gap Junction beta-1 Protein; Gene Knockdown Techniques; Humans; Liver Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Necroptosis; Nuclear Receptor Coactivator 1; Phosphorylation; Signal Transduction; Transfection; Tumor Burden

To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. SIGNIFICANCE: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor.

Topics: Aniline Compounds; Animals; Antineoplastic Agents; Benzofurans; Carcinoma, Hepatocellular; Female; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Male; Mice; Naphthoquinones; Sulfonamides; Xenograft Model Antitumor Assays

Shikonin is a natural naphthoquinone component with antioxidant and anti-tumor function and has been used for hepatocellular carcinoma (HCC) treatment. According to the previous study, many herbs can regulate cancer cell progression by targeting specific microRNA (miRNA) (Liu, 2016). However, the underlying pathological mechanism of shikonin in HCC therapy is still unclear. The detection of cell growth and death rate were performed by hemacytometry and trypan blue staining, respectively. The expression of miR-106b and SMAD7 messenger RNA (mRNA) in HCC cells was evaluated by quantitative real-time polymerase chain reaction. Cell proliferation, apoptosis, and migration ability were measured by cell counting kit-8 (CCK-8), flow cytometry, and transwell assay. The expression of proteins E-cadherin, N-cadherin, vimentin, SMAD7, TGF-β1, p-SMAD3, SMAD3, and GAPDH was examined by western blot. The interaction between SMAD7 and miR-106b was assessed by luciferase reporter system. Shikonin inhibited Huh7 and HepG2 cell growth in a dose-dependent manner while induced cell death in a time-dependent manner. In addition, the expression of miR-106b was reduced after shikonin treatment. Moreover, miR-106b attenuated the suppressive effects of shikonin on HCC cell migration and epithelial-mesenchymal transition (EMT). SMAD7 was predicted as a target of miR-106b and the prediction was confirmed by luciferase reporter system. Additionally, we observed that SMAD7 reversed the promotive effects of miR-106b on HCC cell progression and EMT. The subsequent western blot assay revealed that shikonin could modulate SMAD7/TGF-β signaling pathway by targeting miR-106b. In conclusion, Shikonin suppresses cell progression and EMT and accelerates cell death of HCC cells via modulating miR-106b/SMAD7/TGF-β signaling pathway, suggesting shikonin could be an effective agent for HCC treatment.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Biomarkers, Tumor; Carcinoma, Hepatocellular; Cell Proliferation; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; MicroRNAs; Naphthoquinones; Smad7 Protein; Transforming Growth Factor beta1; Tumor Cells, Cultured

The processing of intracellular reactive oxygen species (ROS) by nuclear factor erythroid-derived 2-like 2 (Nrf2) and NADPH quinone oxidoreductase 1 (Nqo1) is important for tumor metastasis. However, the clinical and biological significance of Nrf2/Nqo1 expression in hepatocellular carcinoma (HCC) remains unclear. We aimed to clarify the clinical importance of Nrf2/Nqo1 expression in HCC and evaluate the association of Nrf2/Nqo1 expression with HCC metastasis. We also evaluated the impact of Nqo1 modulation on HCC metastatic potential. We used spheroids derived from HCC cell lines. In anchorage-independent culture, HCC cells showed increased ROS, leading to the upregulation of Nrf2/Nqo1. Futile stimulation of Nqo1 by β-lapachone induces excessive oxidative stress and dramatically increased anoikis sensitivity, finally diminishing the spheroid formation ability, which was far stronger than depletion of Nqo1. We analyzed 117 cases of primary HCC who underwent curative resection. Overexpression of Nrf2/Nqo1 in primary HCC was associated with tumor size, high α-fetoprotein, and des-γ-carboxy-prothrombin levels. Overexpression of Nrf2/Nqo1 was also associated with multiple intrahepatic recurrences (P = .0073) and was an independent risk factor for poor prognosis (P = .0031). NADPH quinone oxidoreductase 1 plays an important role in anchorage-independent survival, which is essential for survival for circulation and distant metastasis of HCC cells. These results suggest that targeting Nqo1 activity could be a potential strategy for HCC adjuvant therapy.

Topics: Aged; Anoikis; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Male; Middle Aged; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; Neoplasm Metastasis; Neoplasm Recurrence, Local; NF-E2-Related Factor 2; Oxidative Stress; Reactive Oxygen Species

Xiakemycin A (XKA), a new antibiotic in the pyranonaphthoquinone family, shows antitumor activity. However, the type of cell death induced by XKA remains elusive. In this study, we aim to investigate the type of death induced by XKA in hepatic cancer.The apoptotic features, such as chromatic agglutination, reactive oxygen species generation and membrane potential of mitochondria, in HepG2 cells treated by XKA were measured by Hoechst 33342 staining and flow cytometry. Apoptosis of HepG2 cells treated with XKA was determined by Annexin V-FITC/propidium iodide double staining and Western blot analysis, respectively.XKA had a significant dose-dependent elevation of chromatic agglutination, reactive oxygen species generation, Annexin V and propidium iodide staining, decrease of membrane potential. Meanwhile, in apoptotic HepG2 cells induced by XKA, robust increment was noticed in p53 expression, cleavage of PARP, caspase-3, and caspase-9.XKA showed potent inhibitory effects on the proliferation of HepG2 cells. Such phenomenon may be related to activation of the apoptotic pathway.

Topics: Annexin A5; Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; Caspase 3; Caspase 9; DNA Damage; Dose-Response Relationship, Drug; Hep G2 Cells; Humans; Membrane Potentials; Mitochondria, Liver; Naphthoquinones; Poly (ADP-Ribose) Polymerase-1; Propidium; Reactive Oxygen Species

Plumbagin (PL) has been shown to effectively inhibit tumor growth and migration of hepatocellular carcinoma cells in previous studies, but the specific mechanism for this remains unclear. The purpose of this study was to investigate the effects of PL-induced apoptosis in epithelial-mesenchymal transition (EMT) of human hepatocellular carcinoma (HCC) in vivo and in vitro.. SMMC-7721 cells were cultured, an EMT model was induced in vitro by TGF-β1, cell proliferation was detected by the MTT assay, cell invasion was analyzed by the Transwell invasion assay, and the apoptosis rate was measured by flow cytometry. RT-PCR was used to detect vimentin, E-cadherin, N-cadherin and snail mRNA, and Western blotting was used to detect the vimentin, caspase-3, PARP-1, E-cadherin, N-cadherin and snail protein expression levels. HE staining and TUNEL staining, immunohistochemistry and immunofluorescence were used to detect the expression levels of bax and bcl-2 in hepatocarcinoma xenografts and to evaluate their apoptosis in vivo.. The in vitro results showed that PL inhibited the proliferation of EMT model cells, increased the apoptosis rate of the EMT model, and significantly decreased the vimentin, PARP-1, N-cadherin and snail protein levels, but significantly increased E-cadherin and caspase-3 protein expression. In addition, the in vivo results indicated that PL can affect the expression of bax/bcl-2 apoptotic marker proteins.. PL may induce apoptosis of human hepatocellular carcinoma cells undergoing epithelial-mesenchymal transition by increasing the caspase-3 protein level and cleaving vimentin.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Caspase 3; Cell Line, Tumor; Cell Proliferation; Epithelial-Mesenchymal Transition; Humans; Liver Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Signal Transduction; Vimentin

BACKGROUND Anti-angiogenic therapy has recently emerged as a highly promising therapeutic strategy for treating hepatocellular carcinoma (HCC). MATERIAL AND METHODS We assessed cellular proliferation, invasion, and activation of growth factors (VEGF and IL-8) with SDF-1 induced in the hepatocellular carcinoma cell line SMMC-7721, and this progression was limited by plumbagin (PL). The human umbilical vein endothelial cell line HUVEC was co-cultured with SDF-1-induced SMMC-7721, and the expressions of CXCR7, CXCR4, and PI3K/Akt pathways after PL treatment were detected by RT-PCR and Western blot analysis. RESULTS The treatment of the hepatoma cell line SMMC-7721 with SDF-1 resulted in enhanced secretion of the angiogenic factors, IL-8 and VEGF, and shows that these stimulatory effects are abolished by PL. The study further demonstrated that PL not only abolishes SDF-1-induced formation of endothelial tubes, but also inhibits expression of CXCR4 and CXCR7, and partially prevents activation of angiogenic signaling pathways. CONCLUSIONS The effect of PL on the SDF-1-CXCR4/CXCR7 axis has become an attractive target for inhibiting angiogenesis in hepatoma cells. Our results provide more evidence for the clinical application of PL as part of traditional Chinese medicine in modern cancer treatment.

Topics: Angiogenesis Inhibitors; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chemokine CXCL12; Human Umbilical Vein Endothelial Cells; Humans; Interleukin-8; Liver; Liver Neoplasms; Naphthoquinones; Neoplasm Invasiveness; Neovascularization, Pathologic; Receptors, CXCR; Receptors, CXCR4; Signal Transduction; Stromal Cells; Vascular Endothelial Growth Factor A

Shikonin, a naphthoquinone derivative isolated from the root of

Topics: AMP-Activated Protein Kinases; Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Carrier Proteins; Cell Proliferation; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Liver Neoplasms; Membrane Proteins; Mitochondria; Molecular Structure; Naphthoquinones; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Signal Transduction; Structure-Activity Relationship; Thyroid Hormone-Binding Proteins; Thyroid Hormones

Plumbagin (PL), an active naphthoquinone compound, has been demonstrated to be a potential anticancer agent. However, the underlying anticancer mechanism is not fully understood. In this study, the human hepatocellular carcinoma (HCC) SMMC-7721 cell line was studied in an in vitro model. The cell proliferation was inhibited by PL in a dose- and time-dependent manner. Electron microscopy, acridine orange staining, and immunofluorescence were used to evaluate autophagosome formation and LC3 protein expression in PL-treated SMMC-7721 cells. Real-time polymerase chain reaction and Western blot showed that PL treatment suppressed the expression of apoptosis and autophagy factors (LC3, Beclin1, Atg7, and Atg5), which are associated with tumor apoptosis and autophagy in SMMC-7721 cells. In the study of in vitro tumor nude mouse models, PL can inhibit tumor growth. Cell apoptosis and autophagy of the transplanted tumors were evaluated by hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining, and Western blot. In addition, in the in vivo studies of HCC cells, we found that pretreatment with the autophagy inhibitor 3-methyladenine blocked the formation of apoptosis induced by PL. In contrast, administration of the apoptosis inhibitor Z-VAD did not affect PL-induced autophagy. Taken together, our findings strongly suggest that PL is a promising drug with significant antitumor activity in HCC.

Topics: Animals; Apoptosis; Autophagic Cell Death; Carcinoma, Hepatocellular; Cell Line, Tumor; Female; Humans; Liver Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Xenograft Model Antitumor Assays

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).\ \ This article has been retracted at the request of the Editor-in-Chief.\ \ Given the comments of Dr Elisabeth Bik regarding this article “… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Topics: Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Cell Proliferation; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; MicroRNAs; Naphthoquinones; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction

Plumbagin exerts effective anti-hepatocellular carcinoma (HCC) benefits, however, the detailed mechanisms behind these effects are not yet completely elucidated. The pharmacological targets and molecular mechanisms of plumbagin against HCC were revealed through conducting network pharmacology approach before experimentative verification.. The web-accessible databases of herbal ingredients' targets (HIT), Swiss-Target-Prediction and Super-Pred were used to predict the therapeutic targets of plumbagin, followed by combined with pathogenic targets of HCC from oncogenomic database of hepatocellular carcinoma (OncoDB.HCC) and Liverome databases to obtain the predominant targets of plumbagin-treating HCC. The database for annotation, visualization and integrated discovery (DAVID) was applied to output the gene ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment by use of all predominant targets for computerized visualization. The validated data of human and cell culture were subjected to a group of medical imaging, biochemical tests and immunostaining, respectively.. As revealed in bioinformatic data, 19 predominant targets of plumbagin-treating HCC were obtained, and 5 top targets of TP53, MAPK1, MAP2K1, RAF1 and CCND1 were the most important biomolecules in anti-HCC effects exerted by plumbagin. Other identifiable 102 GO items were showed, including 66 biological processes, and 12 cellular components, 24 molecular functions. And 67 KEGG pathways were mainly involved in neoplastic signaling. In human data, HCC sections showed increased expressions of hepatocellular TP53, MAPK1, accompanied with positive clinical imaging results for HCC. In plumbagin-treated HepG2 cells, reduced TP53, MAPK1 protein expressions were observed, accompanied with cell arrest and apoptosis.. Collectively, the pharmacological targets and mechanisms of plumbagin-treating HCC were predicted and integrated through the method of network pharmacology, followed by some investigative validations. Interestingly, these 5 predominant biomolecules may be the potential targets for screening and treating HCC.

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Computational Biology; Cyclin D1; Female; Hep G2 Cells; Humans; Liver Neoplasms; Male; MAP Kinase Kinase 1; Mitogen-Activated Protein Kinase 1; Naphthoquinones; Proto-Oncogene Proteins c-raf; Tumor Suppressor Protein p53

1,4-Naphthoquinone and its derivatives have shown some efficacy as therapeutic compounds for cancer and inflammation, though their clinical application is limited by their side-effects. To reduce the toxicity of these compounds and optimize their effects, we synthesized two 1,4-naphthoquinone derivatives-2-butylsulfinyl- 1,4-naphthoquinone (BSNQ) and 2-octylsulfinyl-1,4-naphthoquinone (OSNQ)-and investigated their effects and underlying mechanisms in hepatocellular carcinoma cells. BSNQ and OSNQ decreased cell viability and significantly induced apoptosis, accompanied by the accumulation of reactive oxygen species (ROS). However, pretreatment with N-acetyl-l-cysteine, a specific ROS scavenger, blocked apoptosis. Western blot results indicated that BSNQ and OSNQ up-regulated the phosphorylation of p38 and JNK, and down-regulated the phosphorylation of ERK, Akt and STAT3, and that these effects were blocked by N-acetyl-l-cysteine. Furthermore, BSNQ and OSNQ suppressed tumor growth and modulated MAPK and STAT3 signaling in mouse xenografts without detectable effects on body weight or hematological parameters. These results indicate that BSNQ and OSNQ induce apoptosis in human hepatoma Hep3B cells via ROS-mediated p38/MAPK, Akt and STAT3 signaling pathways, suggesting that these 1,4-naphthoquinone derivatives may provide promising new anticancer agents to treat HCC.

Topics: Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Humans; Liver Neoplasms; MAP Kinase Signaling System; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; STAT3 Transcription Factor

Cytochrome P450 2J2 (CYP2J2) is not only highly expressed in many kinds of human tumors, but also promotes tumor cell growth via regulating the metabolism of arachidonic acids. CYP2J2 inhibitors can significantly reduce proliferation, migration and promote apoptosis of tumor cells by inhibiting epoxyeicosatrienoic acids (EETs) biosynthesis. Therefore screening CYP2J2 inhibitors is a significant way for the development of anti-cancer drug.. The aim of this study was to identify a new CYP2J2 inhibitor from fifty natural compounds obtained from plants.. CYP2J2 inhibitor was screened from a natural compounds library and further the inhibitory manner and mechanism were evaluated. Its cytotoxicity against HepG2 and SMMC-7721 cell lines was also estimated.. The inhibitory effect was evaluated in rat liver microsomes (RLMs), human liver microsomes (HLMs) and recombinant CYP2J2 (rCYP2J2), using astemizole as a probe substrate and inhibitory mechanism was illustrated through molecular docking. The cytotoxicity was detected using SRB.. In all candidates, plumbagin showed the strongest inhibitory effect on the CYP2J2-mediated astemizole O-demethylation activity. Further study revealed that plumbagin potently inhibited CYP2J2 activity with IC. This study found out a new CYP2J2 inhibitor plumbagin from fifty natural compounds. Plumbagin presented a potential of anti-cancer pharmacological activity.

Topics: Animals; Antineoplastic Agents; Biological Products; Carcinoma, Hepatocellular; Cell Proliferation; Cytochrome P-450 CYP2J2; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Drug Evaluation, Preclinical; Hepatocytes; Humans; Kinetics; Liver Neoplasms; Male; Microsomes, Liver; Molecular Docking Simulation; Naphthoquinones; Rats, Sprague-Dawley

Juglone (JG), a naturally-occurring naphthoquinone of Manchurian walnut (Juglans mandshurica) was shown to inhibit proliferation in various tumor types. However, the molecular mechanisms of JG on the induction of apoptosis and autophagy in HepG2 cells have not been examined. Herein, we investigated that JG could inhibit cell proliferation by induction of G2/M phase arrest. Also, occurrence of apoptosis was closely related with loss of mitochondrial membrane potential, the changes of apoptosis-related proteins after treatment with JG. In addition, we found that JG caused autophagy, as evidenced by increased expressions of LC3-II and Beclin-1. Interestingly, inhibition of JG-induced autophagy by 3-methyladenine (3-MA) and wortmannin (WT) significantly decreased apoptosis, whereas the apoptosis inhibitor z-VAD-fmk slightly enhanced autophagy. Furthermore, the induction of autophagy and apoptosis was associated with activation of MAPK family members (p38 and JNK) and production of reactive oxygen species (ROS). Both JNK inhibitor (SP600125) and ROS scavenger (N-acetylcysteine, NAC) could attenuate JG-induced autophagy and apoptosis. However, the p38-specific inhibitor SB203580 enhanced autophagic and apoptotic death. Moreover, the ROS scavenger NAC prevented phosphorylation of both p38 and JNK. Collectively, our data revealed that JG induced G2/M phase arrest, apoptosis, and autophagy through the ROS-dependent signaling pathway.

Topics: Acetylcysteine; Adenine; Amino Acid Chloromethyl Ketones; Androstadienes; Apoptosis; Autophagy; Carcinoma, Hepatocellular; Cell Cycle Checkpoints; Cell Proliferation; Enzyme Activation; Hep G2 Cells; Humans; Liver Neoplasms; MAP Kinase Kinase 4; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Reactive Oxygen Species; Wortmannin

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; DNA Damage; Furans; Hep G2 Cells; Humans; Indoles; Naphthoquinones; Neovascularization, Pathologic; Phosphorous Acids

Tumor occurrence and development are very complicated processes. In addition to the roles of exogenous carcinogenic factors, the body's internal factors also play important roles. These factors include the host response to the tumor and the tumor effect on the host. In particular, the proliferation, migration and activation of endothelial cells are involved in tumor angiogenesis. Angiogenesis is one of the hallmarks of cancer. In this study, we investigate whether plumbagin can abrogate angiogenesis-mediated tumor growth in hepatocellular carcinoma (HCC) and, if so, through which molecular mechanisms. We observed that in co-cultures of the human endothelial cell line EA.hy926 and the human hepatoma cell line SMMC-7721 and Hep3B, the hepatoma cells induced migration, invasion, tube formation and viability of the EA.hy926 cells in vitro, and these processes were inhibited by plumbagin. Real-Time PCR, Western Blot and Immunofluorescence staining showed that plumbagin treatment suppressed expression of angiogenesis pathways (PI3K-Akt, VEGF/KDR and Angiopoietins/Tie2) and angiogenic factors (VEGF, CTGF, ET-1, bFGF),which is associated with tumor angiogenesis in cancer cells and xenograft tumor tissues. Furthermore, plumbagin was also found to significantly reduce tumor growth in an orthotopic HCC mouse model and to inhibit tumor-induced angiogenesis in HCC patient xenografts. Taken together, our findings strongly suggest that plumbagin might be a promising anti-angiogenic drug with significant antitumor activity in HCC.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Biomarkers, Tumor; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Endothelial Cells; Female; Humans; Liver Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Neoplasm Invasiveness; Neovascularization, Pathologic; Signal Transduction; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Shikonin and its enantiomer alkannin, which are natural products, have been extensively studied in vitro and in vivo for, among others, their antitumor activity. The investigation of the molecular pathways involved in their action is of interest, since they are not yet clearly defined. Metabolic profiling in cells can provide a picture of a cell's phenotype upon intervention, assisting in the elucidation of the mechanism of action. In this study, the cytotoxic effect of shikonin on a human hepatocarcinoma cell line was studied. Huh7 cells were treated with shikonin at 5 μM, and it was found that shikonin markedly inhibited cell growth. Metabolic profiling indicated alterations in the metabolic content of the cells and the culture media upon treatment, detecting the metabolic response of the cells. This study demonstrates the potential of metabolomics to improve knowledge on the mechanisms involved in shikonin's antitumor action.

Topics: Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chromatography, Liquid; Humans; Liver Neoplasms; Metabolome; Metabolomics; Naphthoquinones; Signal Transduction; Tandem Mass Spectrometry

Hepatocellular carcinoma (HCC) is a highly lethal malignancy mostly because of metastasis, recurrence and acquired resistance to conventional chemotherapy. Arsenic trioxide (ATO) is successfully used to treat hematological malignancies, and has been proven to trigger apoptosis in HCC cells. However, the phase II trial evaluating the efficacy and toxicity of ATO in patients with HCC showed that single-agent ATO is poorly active against HCC. Therefore, it is of great importance to develop effective chemosensitization agents to ATO. The aim of the present study was to determine whether shikonin (SHI), a natural product from the root of lithospermum erythrorhizon, could synergistically enhance the anti-HCC efficacy of ATO both in vitro and in vivo. We found that the combination of SHI and ATO exhibited synergistic anticancer efficacy and achieved greater selectivity between cancer cells and normal cells. By inducing intracellular oxidative stress, SHI potentiated ATO-induced DNA damage, followed by increased activation of endoplasmic reticulum stress. In addition, inhibition of ROS reversed the apoptosis induced by SHI and ATO, and recovered the activation of endoplasmic reticulum stress, which revealed the vital role of ROS in the synergism. Moreover, HepG2 xenograft tumor growth in nude mice was more effectively inhibited by combined treatment with SHI and ATO. These data suggest that the combination of SHI with ATO presents a promising therapeutic approach for the treatment of HCC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Arsenic Trioxide; Arsenicals; Carcinoma, Hepatocellular; Cell Line; Cell Line, Tumor; DNA Damage; Drug Synergism; Endoplasmic Reticulum Stress; Hep G2 Cells; Humans; Liver Neoplasms; Mice, Nude; Naphthoquinones; Oxides; Xenograft Model Antitumor Assays

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. The inability of chemotherapeutic drugs to selectively target HCC tumor cells because of their predominant resistant phenotype to most conventional anticancer agents bestows a major obstacle for the clinical management of HCC. In this report, we have examined and demonstrated the remarkable heterogeneity of expression of survivin and its phosphorylated active form (p-survivin) in HCC patients' tissues and cell lines. Furthermore, the expression of survivin and p-survivin in HCC cell lines was found to be associated with response to the small-molecule survivin suppressant YM155. Therefore, in the HCC cell lines that express elevated level of survivin and p-survivin, YM155 efficiently inhibited their proliferation, induced cell cycle arrest and apoptosis resulting in DNA damage through the dysregulation of cell-cycle checkpoint-related regulatory genes. Importantly, YM155 yielded significantly better therapeutic effect than sorafenib when tested in an orthotopic mouse model using patient-derived HCC xenografts with elevated survivin and p-survivin expression. Our results clearly demonstrated that the level of survivin and p-survivin expression could serve as molecular predictive biomarkers to select potential YM155-responsive patients, in a move towards delivering precision medicine for HCC patients.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; DNA Damage; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Liver Neoplasms; Mice; Mice, Nude; Naphthoquinones; Repressor Proteins; Survivin; Xenograft Model Antitumor Assays

β-Lapachone activates multiple cell death mechanisms including apoptosis, autophagy and necrotic cell death in cancer cells. In this study, we investigated β-lapachone-induced cell death and the underlying mechanisms in human hepatocellular carcinoma SK-Hep1 cells. β-Lapachone markedly induced cell death without caspase activation. β-Lapachone increased PI uptake and HMGB-1 release to extracellular space, which are markers of necrotic cell death. Necrostatin-1 (a RIP1 kinase inhibitor) markedly inhibited β-lapachone-induced cell death and HMGB-1 release. In addition, β-lapachone activated poly (ADP-ribosyl) polymerase-1(PARP-1) and promoted AIF release, and DPQ (a PARP-1 specific inhibitor) or AIF siRNA blocked β-lapachone-induced cell death. Furthermore, necrostatin-1 blocked PARP-1 activation and cytosolic AIF translocation. We also found that β-lapachone-induced reactive oxygen species (ROS) production has an important role in the activation of the RIP1-PARP1-AIF pathway. Finally, β-lapachone-induced cell death was inhibited by dicoumarol (a NQO-1 inhibitor), and NQO1 expression was correlated with sensitivity to β-lapachone. Taken together, our results demonstrate that β-lapachone induces programmed necrosis through the NQO1-dependent ROS-mediated RIP1-PARP1-AIF pathway.

Topics: Antineoplastic Agents; Apoptosis Inducing Factor; Carcinoma, Hepatocellular; Cell Line, Tumor; Dose-Response Relationship, Drug; HMGB1 Protein; Humans; Liver Neoplasms; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; Necrosis; Nuclear Pore Complex Proteins; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Protein Kinase Inhibitors; Protein Transport; Reactive Oxygen Species; Receptor-Interacting Protein Serine-Threonine Kinases; RNA Interference; RNA-Binding Proteins; Signal Transduction; Time Factors; Transfection

Shikonin, a naphthoquinone derived from the Chinese medicinal plant Lithospermum erythrorhizon, shows potential to be a cancer chemotherapeutic agent. Our previous data demonstrate that high doses (about 6 μM) of shikonin induce apoptosis in human hepatocellular carcinoma (HCC) cells. Here, we discovered that a low dose of shikonin (2.5 μM) and a short treatment time (12h) induced autophagy, as evidenced by the upregulation of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, the formation of acidic autophagic vacuoles (AVOs), and the punctate fluorescence pattern of GFP-LC3 protein. Next, we investigated the mechanism and found reactive oxygen species accumulation after shikonin treatment. The reactive oxygen species scavengers NAC and Tiron completely blocked autophagy. We further found activation of ERK by generation of reactive oxygen species and inhibition of RIP pathway, which are at least partially connected to shikonin-induced autophagy. Moreover, experiments in vivo revealed similar results: shikonin caused the accumulation of reactive oxygen species and phospho-ERK and thus induced autophagy in a tumor xenograft model. These findings suggest that shikonin is an inducer of autophagy and may be a promising clinical antitumor drug.

Topics: Animals; Antineoplastic Agents; Autophagy; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Humans; Intracellular Space; Liver Neoplasms; Male; Mice; Naphthoquinones; Reactive Oxygen Species; Receptor-Interacting Protein Serine-Threonine Kinases; Xenograft Model Antitumor Assays

In order to discover anticancer agents from natural sources, an ethanol-soluble extract of the root bark of Juglans cathayensis was investigated and showed cytotoxic effects against various human cancer cell lines. A subsequent phytochemical study on the EtOAc-soluble fraction determined 2-methoxyjuglone (1) as one of the main active constituents. Compound 1 was shown to be cytotoxic against HepG2 cells. Morphological features of apoptosis were observed in 1-treated HepG2 cells, including cell shrinkage, membrane blebbing, nuclear condensation, and apoptotic body formation. Cell cycle analysis with propidium iodide staining showed that 1 induced cell cycle arrest at the S phase in HepG2 cells. Flow cytometric analysis with annexin V and propidium iodide staining demonstrated that 1 induced HepG2 cell apoptotic events in a dose-dependent manner (0-8 μg/mL). Western blot analysis of apoptosis-related proteins revealed that 1 induces HepG2 cell apoptosis through mitochondrial cytochrome c-dependent activation of the caspase-9 and caspase-3 cascade pathway (intrinsic pathway). An in vivo experiment using tumor-bearing mice showed that treatment with 1 at 0.5 and 1.0 mg/kg per day decreased the tumor mass by 56% and 67%, respectively.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle Checkpoints; Drug Screening Assays, Antitumor; Female; Hep G2 Cells; Humans; Juglans; Mice; Naphthoquinones; S Phase

Shikonin is a traditional Oriental medical herb extracted from Lithospermum erythrorhizon. Many studies have shown that shikonin possesses anticancer ability against many different cancers, including hepatocellular carcinoma (HCC). Recently, tumor metastasis has been become an important clinical obstacle. However, the effect of shikonin on metastasis by HCC is unknown. The 50% inhibitory concentration (IC50) of shikonin on HCC cells was determined by an MTT assay and the xCELLigence biosensor system. The migratory ability of HCC cells was detected by a transwell migration assay and the xCELLigence biosensor system. Matrix metalloproteinase-2 and -9 (MMP-2 and -9) expression levels were determined by Western blotting, and the activities of MMP-2 and -9 were determined by gelatin zymography. We found that IC50 values of HepJ5 and Mahlavu cells to shikonin treatment were around 2 μM. Exposure to a low dose of shikonin (0-0.4 μM) did not influence the survival of HCC cells. Interestingly, exposure to a low dose of shikonin inhibited the migratory ability on HepJ5 and Mahlavu cells. To further dissect the mechanism, we found that treatment with a low dose of shikonin reduced the activities and expression levels of MMP-2 and -9, which were correlated with the decreased cell migratory ability of HCC cells. In addition, we found a decrease of vimnetin expression, but no influence on the expression levels of N-cadherin, TWIST, or GRP78. In mechanism dissecting, we found that shikonin treatment may suppress the phosphorylation of AKT and then reduce the NF-κB (NF = nuclear factor) levels, but has no influence on the levels of c-Fos and c-Jun. Furthermore, we also found that shikonin may also reduce the phosphorylation of IκB. We concluded that a low dose of shikonin can suppress the migratory ability of HCC cells through downregulation of expression levels of vimentin and MMP-2 and -9. Our findings suggest that shikonin may be a new compound to prevent the migration of HCC cells.

Topics: Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Drugs, Chinese Herbal; Endoplasmic Reticulum Chaperone BiP; Gene Expression Regulation, Neoplastic; Humans; Lithospermum; Liver Neoplasms; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Naphthoquinones; Neoplasm Metastasis

Shikonin, a major component of Lithospermum erythrorhizon and Arnebia euchroma, exhibits antiinflammatory, immunomodulatory and antitumour activities. Although many recent studies have focused on the antitumour effects of shikonin, the exact mechanisms underlying its antitumour and immunomodulatory effects in tumour-bearing mice remain unclear. The aim of the present study was to investigate the antitumour and immunomodulatory effects of shikonin derivatives (ShD) in tumour-bearing mice. Swiss mice inoculated with hepatoma HepA(22) or sarcoma 180 (S(180)) cells were treated with ShD or 5-fluorouracil (5Fu). Survival time, immune organs, natural killer cell activity, lymphocytes, lymphocyte transformation and interleukin (IL)-2 production were analysed. ShD significantly prolonged the survival (median survival time prolonged by >7 days) of tumour-bearing mice in a dose-dependent manner, inhibited the growth of transplantable neoplasms (inhibitory rate, > 33%), and recovered (at [ShD] = 2.5 mg/kg/day) or increased (at [ShD] > 5 mg/kg/day) the number of CD3- and CD19-positive cells. ShD also played a role in protecting the immune organs from damage and reversed or enhanced immune responses, as noted by the nearly normal thymic structure; enlarged splenic corpuscles; and improved natural killer cell activity, lymphocyte transformation and IL-2 production in ShD-treated mice. ShD reduced the tumour load of tumour-bearing mice and protected the immune organs against tumour-induced damage and immune function impairment.

Topics: Adjuvants, Immunologic; Animals; Antigens, CD19; Antineoplastic Agents, Phytogenic; Boraginaceae; Carcinoma, Hepatocellular; CD3 Complex; Dose-Response Relationship, Drug; Fluorouracil; Interleukin-2; Killer Cells, Natural; Lithospermum; Liver Neoplasms; Lymphocytes; Mice; Naphthoquinones; Phytotherapy; Plant Extracts; Sarcoma; Spleen; Thymus Gland

β,β-Dimethylacrylshikonin is one of the most abundant naphthoquinones in the root extracts of Lithospermum erythrorhizon Sieb. et Zucc. (Boraginaceae), which have been reported to have antitumor effects. This study evaluated the antiproliferative activity of β,β-dimethylacrylshikonin on human hepatocellular carcinoma (HCC) cells both in vitro and in vivo. In vitro, the MTT assay showed that β,β-dimethylacrylshikonin inhibited the proliferation of SMMC-7721 cells in both dose- and time-dependent manners with its 50% inhibitory concentration (IC(50) ) at 48 h being 15.01 ± 0.76 µg/mL. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) and Hoechst staining detected the characteristics of cell apoptosis in β,β-dimethylacrylshikonin-treated cells and the apoptotic rates of treated groups were increased in a dose-dependent manner. Flow cytometric analysis revealed that β,β-dimethylacrylshikonin could block the cell cycle arrest at G2 phase. Furthermore, β,β-dimethylacrylshikonin down-regulated the mRNA and protein expression of Bcl-2 but up-regulated that of Bax. The cleaved caspase-3 protein was also detected in treated cells. The experiment in vivo showed that β,β-dimethylacrylshikonin significantly suppressed the growth of H(22) transplantable hepatoma, and induced the activation of caspase-3 determined by immunohistochemistry. The results indicate that β,β-dimethylacrylshikonin has significant antitumor effects on hepatocellular carcinoma both in vitro and in vivo.

Topics: Animals; Anthraquinones; Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Hepatocellular; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Down-Regulation; G2 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Lithospermum; Liver Neoplasms, Experimental; Male; Mice; Naphthoquinones; Plant Extracts; Plant Roots; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger

Aikete injection is composed of acetylshikonin and β,β-dimethylacrylshikonin, which have been reported to have anti-tumor effects on a wide range of cancer cell lines. However, little is known about the effects of the combination of the two components on cancer cells.. To investigate the anti-proliferation activity of Aikete injection on human hepatocellular carcinoma (HCC) cells and its mechanism.. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and growth curve assay were used to determine the inhibitory effect of Aikete injection on the proliferation of SMMC-7721 cells. Giemsa staining, Hoechst 33258 staining and flow cytometry were used to assess cell apoptosis. Expression of Bcl-2 and Bax was analyzed by reverse transcription-polymerase chain reaction and flow cytometry. H22 bearing mice were also used to determine the anti-tumor effect of Aikete injection in vivo.. Aikete injection inhibited the proliferation of SMMC-7721 cells in both a dose- and time-dependent manner in vitro. The characteristics of apoptosis were observed in Aikete injection groups by Hoechst 33258 and Giemsa staining. In addition, Aikete injection induced cell cycle arrest at G2/M phase and downregulated the Bcl-2 expression and the ratio of Bcl-2/Bax in SMMC-7721 cells. The experiment in vivo showed that Aikete injection significantly inhibited the growth of H22 carcinoma, with an inhibitory rate of 34.37-57.99%.. The results demonstrated that Aikete injection suppressed the growth of HCC cells in vitro and in vivo by inducing cell apoptosis.

Topics: Animals; Anthraquinones; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Genes, bcl-2; Humans; Injections; Liver Neoplasms; Male; Mice; Naphthoquinones

Our study aims to study the therapeutic effects of a novel Bcl-2 inhibitor, ABT-263, on hepatocellular carcinoma (HCC) and to provide primary preclinical data for future clinical trial with ABT-263. In this study we showed that Bcl-xL and survivin were up-regulated in HCC cell lines and human liver cancer tissues. Clinic used ABT-263 single treatment had no apoptotic effects on HCC cells whereas higher doses of ABT-263 did. Interestingly, the combination treatment of ABT-263 with survivin inhibitor YM-155 could result in significant apoptosis in HCC cells. Survivin inhibition through gene silencing significantly enhanced ABT-263 to induce apoptosis in HCC cells. We found that low dose of ABT-263 single treatment resulted in ERK activation and survivin up-regulation, which might be involved in the resistance of HCC cells to ABT-263 since blockade of ERK activation sensitized ABT-263-induced apoptosis. Importantly, ABT-263 and YM-155 combination treatment had no apoptotic effects on normal human hepatocytes. Taken together, these data suggest the combination treatment of Bcl-2 inhibitor and survivin inhibition may have a great potential for liver cancer therapy.

Topics: Aniline Compounds; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Gene Silencing; Hepatocytes; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Liver Neoplasms; Naphthoquinones; Proto-Oncogene Proteins c-bcl-2; Sulfonamides; Survivin

Although shikonin, a naphthoquinone derivative, has showed anti-cancer activity, its precise molecular anti-tumor mechanism remains to be elucidated. In this study, we investigated the effects of shikonin on human hepatocellular carcinoma (HCC) in vitro and in vivo. Our results showed that shikonin induced apoptosis of Huh7 and BEL7402 but not nontumorigenic cells. ROS generation was detected, and ROS scavengers completely inhibited shikonin-induced apoptosis, indicating that ROS play an essential role. Although the JNK activity was significantly elevated after shikonin treatment, JNK was not linked to apoptosis. However, downregulation of Akt and RIP1/NF-κB activity was found to be involved in shikonin-induced apoptosis. Ectopic expression of Akt or RIP1 partly abrogated the effects of shikonin, and Akt inhibitor and RIP1 inhibitor synergistically induced apoptosis in conjunction with shikonin treatment. ROS scavengers blocked shikonin-induced inactivation of Akt and RIP1/NF-κB, but Akt or RIP1/NF-κB did not regulate ROS generation, suggesting that Akt and RIP1/NF-κB signals are downstream of ROS generation. In addition, the results of xenograft experiments in mice were consistent with in vitro studies. Taken together, our data show that shikonin, which may be a promising agent in the treatment of liver cancer, induced apoptosis in HCC cells through the ROS/Akt and RIP1/NF-κB pathways.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Liver Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Structure; Naphthoquinones; Reactive Oxygen Species; Structure-Activity Relationship; Tumor Cells, Cultured

Naphtho[1,2-b] furan-4,5-dione (NFD) was investigated for its anti-proliferation effect on human hepatocellular carcinoma (HCC), Hep3B, HepG(2), and Huh-7 cells. The effect of NFD on inhibiting proliferation and apoptosis was correlated with up-regulation of pro-apoptotic protein and down-regulation of pro-survival proteins. Remarkably, we found that NFD inhibited the nuclear translocation of NF-kappaB, likely accounting for the down-regulation of pro-survival Bcl-2 family. Furthermore, suppression of p38 MAPK activity by a specific inhibitor significantly rescued the cell proliferation inhibited by NFD. These findings suggest that signaling imbalance between p38 MAPK and NF-kappaB by NFD results in the proliferative inhibition and apoptosis of HCC tumor cells.

Topics: Apoptosis; bcl-X Protein; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cell Survival; Down-Regulation; Enzyme Activation; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Interleukin-6; MAP Kinase Signaling System; Naphthoquinones; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Signal Transduction; Up-Regulation; X-Linked Inhibitor of Apoptosis Protein

Phosphorylation of proteins on serine or threonine residues that immediately precede proline (pSer/Thr-Pro) is specifically catalyzed by the peptidyl-prolyl cis-trans isomerase Pin1 and is a central signaling mechanism in cell proliferation and transformation. Although Pin1 is frequently overexpressed in hepatocellular carcinoma (HCC), the molecular mechanism of Pin1 in HCC has not been completely elucidated. Here, we show that Pin1 interacts with p70S6K in vitro and ex vivo. Overexpression of Pin1 resulted in enhanced p70S6K phosphorylation induced by insulin in SK-HEP-1 cells. In contrast, Pin1(-/-) mouse embryonic fibroblasts (MEFs) exhibited significantly decreased insulin-induced p70S6K phosphorylation compared with Pin1(+/+) MEFs. Furthermore, Pin1 enhanced the insulin-induced extracellular signal-regulated protein kinase (ERK)1/2 phosphorylation through its interaction with p70S6K, whereas the inhibition of p70S6K activity by rapamycin suppressed insulin-induced ERK1/2 phosphorylation in SK-HEP-1 cells. Hence, Pin1 affected activator protein-1 activity through p70S6K-ERK1/2 signaling in SK-HEP-1 cells. Most importantly, Pin1-overexpressing JB6 Cl41 cells enhanced neoplastic cell transformation promoted by insulin much more than green fluorescent protein-overexpressing JB6 Cl41 control cells. These results imply that Pin1 amplifies insulin signaling in hepatocarcinoma cells through its interaction with p70S6K, suggesting that Pin1 plays an important role in insulin-induced tumorigenesis and is a potential therapeutic target in hepatocarcinoma.

Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Cells, Cultured; Drug Synergism; Embryo, Mammalian; Fibroblasts; Gene Expression Regulation, Neoplastic; Green Fluorescent Proteins; Humans; Hypoglycemic Agents; Immunoblotting; Immunosuppressive Agents; Insulin; Liver Neoplasms, Experimental; Mice; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Naphthoquinones; NIMA-Interacting Peptidylprolyl Isomerase; Peptidylprolyl Isomerase; Phosphorylation; Ribosomal Protein S6 Kinases, 70-kDa; RNA, Small Interfering; Signal Transduction; Sirolimus; Transcription Factor AP-1; Two-Hybrid System Techniques

beta-lapachone, a quinone compound obtained from the bark of the lapacho tree (Tabebuia avellanedae), was reported to have anti-inflammatory and anti-cancer activities. In this study, we investigated novel functions of beta-lapachone in terms of anti-metastasis and anti-invasion abilities using human hepatocarcinoma cell lines, HepG2 and Hep3B. beta-lapachone dose-dependently inhibited cell viability and migration of both HepG2 and Hep3B cells, as determined by methylthiazoletetrazolium (MTT) assay and wound healing assay. RT-PCR and Western blot data revealed that beta-lapachone dramatically increased the levels of protein, as well as mRNA expression of early growth response gene-1 (Egr-1) and throbospondin-1 (TSP-1) at an early point in time, and then decreased in a time-dependent manner. In addition, down-regulation of Snail and up-regulation of E-cadherin expression were observed in beta-lapachone-treated HepG2 and Hep3B cells, and this the associated with decreased invasive ability as measured by matrigel invasion assay. Taken together, our results strongly suggest that beta-lapachone may be expected to inhibit the progression and metastasis of hepatoma cells, at least in part by inhibiting the invasive ability of the cells via up-regulation of the expression of the Egr-1, TSP-1, and E-cadherin.

Topics: Cadherins; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Survival; Early Growth Response Protein 1; Gene Expression Regulation, Neoplastic; Humans; Naphthoquinones; Neoplasm Invasiveness; Neoplasm Metastasis; Snail Family Transcription Factors; Thrombospondin 1; Transcription Factors

1-(1,4-dihydro-5,8-dihydroxy-1,4-dioxonaphthalen-2-yl)-4-methylpent-3-enylfuran-2-caroxylate (SH-7), a new naphthoquinone compound, derived from shikonin, exhibited obvious inhibitory actions on topoisomerase II (Topo II) and topoisomerase I (Topo I), which were stronger than its mother compound shikonin. Notably, the SH-7's inhibitory potency on Topo II was much stronger than that on Topo I. In addition, SH-7 significantly stabilized Topo II-DNA cleavable complex and elevated the expression of phosphorylated-H2AX. The in vitro cell-based investigation demonstrated that SH-7 displayed wide cytotoxicity in diversified cancer cell lines with the mean IC(50) value of 7.75 microM. One important finding is SH-7 displayed significant cytotoxicity in the 3 MDR cell lines, with an average IC(50) value nearly equivalent to that of the corresponding parental cell lines. The average resistance factor (RF) of SH-7 was 1.74, which was much lower than those of reference drugs VP-16 (RF 145.92), ADR (RF 105.97) and VCR (RF 197.39). Further studies illustrated that SH-7 had the marked apoptosis-inducing function on leukemia HL-60 cells, which was validated to be of mitochondria-dependence. The in vivo experiments showed that SH-7 had inhibitory effects on S-180 sarcoma implanted to mice, SMMC-7721, BEL-7402 human hepatocellular carcinoma and PC-3 human prostate cancer implanted to nude mice. Taken together, these results suggest that SH-7 induces DSBs as a Topo II inhibitor, which was crucial to activate the apoptotic process, and subsequently accounts for its both in vitro and in vivo antitumor activities. The well-defined Topo II inhibitory activity, antitumor effects particularly with its obvious anti-MDR action, better solubility and less toxicity make SH-7 as a potential antitumor drug candidate for further research and development.

Topics: Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Electrophoresis, Agar Gel; Female; Flow Cytometry; Humans; Leukemia; Liver Neoplasms; Male; Mice; Mice, Nude; Naphthoquinones; Neoplasms; Prostatic Neoplasms; Sarcoma; Topoisomerase II Inhibitors; Transplantation, Heterologous

The DNA topoisomerase inhibitor beta-lapachone is a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae) in South America. It has been reported to possess a wide range of pharmacological properties, and is a promising cancer chemopreventive agent. In this study, the effects of beta-lapachone on the growth of the human hepatoma cell line HepG2 were investigated. The results showed that beta-lapachone inhibits the viability of HepG2 by inducing apoptosis, as evidenced by the formation of apoptotic bodies and DNA fragmentation. Reverse transcription-polymerase chain reaction and immunoblotting results indicated that treatments of cells with beta-lapachone resulted in down-regulation of anti-apoptotic Bcl-2 and Bcl-X(L) and up-regulation of pro-apoptotic Bax expression. beta-Lapachone-induced apoptosis was associated with a proteolytic activation of caspase-3 and -9 and degradation of poly(ADP-ribose) polymerase protein. However, beta-lapachone treatment did not affect the inhibitor of apoptosis proteins family and the Fas/FasL system. Taken together, our study indicated that beta-lapachone may have potential as a chemopreventive agent for liver cancer.

Topics: Apoptosis; bcl-2-Associated X Protein; Carcinoma, Hepatocellular; Caspase 3; Caspase 9; Caspases; Cell Division; Cell Line, Tumor; DNA Fragmentation; Enzyme Activation; Fas Ligand Protein; fas Receptor; Flow Cytometry; Gene Expression; Humans; Inhibitor of Apoptosis Proteins; Liver Neoplasms; Membrane Glycoproteins; Naphthoquinones; Proto-Oncogene Proteins c-bcl-2; Reverse Transcriptase Polymerase Chain Reaction; Tabebuia; Tumor Necrosis Factors

We previously synthesized a K-vitamin derivative, Cpd 5, which was a potent growth inhibitor of human tumor cells, including Hep3B hepatoma cells. However, being a quinone compound, Cpd 5 has the potential for generating toxic reactive oxygen species (ROS). We therefore synthesized a nonquinone sulfone derivative, H32, which has a sufone group substituting the quinone. The IC50 of H32 for Hep3B cells was found to be 2.5 microM, which was 2.5 and 3.2 times more potent than Cpd 5 and vitamin K3 respectively. It induced apoptosis in Hep3B cells but did not generate ROS when compared to Cpd 5. Interestingly, under similar culture conditions, normal rat hepatocytes were 14-fold more and 7-fold more resistant to the growth inhibitory effects of H32 than Hep3B and PLC/PRF5 cells respectively. H32 preferentially inhibited the activities of the cell cycle controlling Cdc25A phosphatase likely by binding to its catalytic cysteine. As a consequence, it induced inhibitory tyrosine phosphorylation of the Cdc25 substrate kinases Cdk2 and Cdk4 in Hep3B cells and the cells undergo an arrest in the G1 phase of the cell cycle. H32 also induced persistent phosphorylation of the MAPK protein ERK1/2, but marginal JNK1/2 and p38 phosphorylation. The ERK inhibitor U0126, added at least 30 min prior to H32, antagonized the growth inhibition induced by H32. However, the JNK and p38 inhibitors, JNKI-II and SB203580, were not able to antagonize H32 induced growth inhibition. Thus, H32 differentially inhibited growth of normal and liver tumor cells by preferentially inhibiting the actions of Cdc25 phosphatases and inducing persistent ERK phosphorylation.

Topics: Animals; Carcinoma, Hepatocellular; cdc25 Phosphatases; Cell Cycle Proteins; Cell Division; Cell Line, Tumor; DNA; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Hepatocytes; Humans; Liver Neoplasms; Male; Naphthoquinones; Rats; Rats, Inbred F344; Sulfones; Vitamin K 3

Three new pyranonaphthoquinones: 5-hydroxy-6-methoxy-alpha-lapachone, 5,6-dihydroxy-a-lapachone and 4',5-dihydroxy-6-methoxy-alpha-lapachone, and two known compounds: lapachol and 5,5'-dihydroxy-3',4',7-trimethoxyflavanone, were isolated from the stem bark of Melloa quadrivalvis. Their structures were established by spectrometric data, mainly 1D- and 2D-NMR and mass spectra. The methylazoetetrazolium (MTT) method using viable cells of the strain Hep2 and the strain NCIH-292 demonstrated cytotoxic activity. The CI50 was also calculated. The chloroform extract and 5-hydroxy-6-methoxy-alpha-lapachone inhibited cell growth.

Topics: Antineoplastic Agents, Phytogenic; Bignoniaceae; Carcinoma, Hepatocellular; Drug Screening Assays, Antitumor; Liver Neoplasms; Naphthoquinones; Plant Bark; Plant Extracts; Tumor Cells, Cultured

Cdc25 phosphatases are important in cell cycle control and activate cyclin-dependent kinases (Cdk). Efforts are currently under way to synthesize specific small-molecule Cdc25 inhibitors that might have anticancer properties. NSC 95397, a protein tyrosine phosphatase antagonist from the National Cancer Institute library, was reported to be a potent Cdc25 inhibitor. We have synthesized two hydroxyl derivatives of NSC 95397, monohydroxyl-NSC 95397 and dihydroxyl-NSC 95397, which both have enhanced activity for inhibiting Cdc25s. The new analogues, especially dihydroxyl-NSC 95397, potently inhibited the growth of human hepatoma and breast cancer cells in vitro. They influenced two signaling pathways. The dual phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) was induced, likely due to inhibition of the ERK phosphatase activity in Hep 3B cell lysate but not the dual specificity ERK phosphatase MKP-1. They also inhibited Cdc25 enzymatic activities and induced tyrosine phosphorylation of the Cdc25 target Cdks. Addition of hydroxyl groups to the naphthoquinone ring thus enhanced the potency of NSC 95397. These two new compounds may be useful probes for the biological functions of Cdc25s and have the potential for disrupting the cell cycle of growing tumor cells.

Topics: Antineoplastic Agents; Biotinylation; Blotting, Western; Breast Neoplasms; Carcinoma, Hepatocellular; cdc25 Phosphatases; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell-Free System; DNA; Dual Specificity Phosphatase 1; Flavonoids; Flow Cytometry; Humans; Immediate-Early Proteins; Immunoprecipitation; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Naphthoquinones; Phosphoprotein Phosphatases; Phosphorylation; Protein Phosphatase 1; Protein Tyrosine Phosphatases; Signal Transduction; Time Factors; Transfection; Tyrosine

The activity of hypoxia-inducible factor 1 (HIF-1) is primarily determined by stability regulation of its alpha subunit, which is stabilized under hypoxia but degraded during normoxia. Hydroxylation of HIF-1alpha by prolyl hydroxylases (PHDs) recruits the von Hippel-Lindau (pVHL) E3 ubiquitin ligase complex to initiate proteolytic destruction of the alpha subunit. Hypoxic stabilization of HIF-1alpha has been reported to be antagonized by nitric oxide (NO). By using a HIF-1alpha-pVHL binding assay, we show that NO released from DETA-NO restored prolyl hydroxylase activity under hypoxia. Destabilization of HIF-1alpha by DETA-NO was reversed by free radical scavengers such as NAC and Tiron, thus pointing to the involvement of reactive oxygen species (ROS). Therefore, we examined the effects of ROS on HIF-1alpha stabilization. Treatment of cells under hypoxia with low concentrations of the superoxide generator 2,3-dimethoxy-1,4-naphthoquinone lowered HIF-1alpha protein stabilization. In vitro HIF-1alpha-pVHL interaction assays demonstrated that low-level ROS formation increased prolyl hydroxylase activity, an effect antagonized by ROS scavengers. While determining intracellular ROS formation we noticed that reduced ROS production under hypoxia was restored by the addition of DETA-NO. We propose that an increase in ROS formation contributes to HIF-1alpha destabilization by NO donors under hypoxia via modulation of PHD activity.

Topics: 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; Acetylcysteine; Carcinoma, Hepatocellular; Cell Line; Humans; Hydroxylation; Hypoxia; Naphthoquinones; Nitric Oxide; Nitric Oxide Donors; Procollagen-Proline Dioxygenase; Reactive Oxygen Species; Triazenes; Tumor Cells, Cultured; Von Hippel-Lindau Tumor Suppressor Protein

Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of alpha-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 microg/mL] than alkannin or shikonin (MIC = 6.25 microg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/MIC < or = 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 microg/mL (CD(50)). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity.

Topics: Anti-Bacterial Agents; Boraginaceae; Carcinoma, Hepatocellular; China; Drug Screening Assays, Antitumor; Electron Spin Resonance Spectroscopy; Enterococcus faecalis; Female; HeLa Cells; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Molecular Structure; Naphthoquinones; Nuclear Magnetic Resonance, Biomolecular; Ovarian Neoplasms; Plant Bark; Plants, Medicinal; Staphylococcus aureus; Stereoisomerism; Tumor Cells, Cultured; Vancomycin

To understand the mechanisms of liver regeneration or hepatoma apoptosis, it is important to estimate the turning point of the signal transduction by growth factor receptor. Since 2-(2-hydroxyethylsulfaryl) 3-methyl-1,4-naphthoquinone or CPD 5 has been shown to mediate the phosphorylation of epidermal growth factor (EGF) receptor in Hep3B hepatoma cells, the differences between EGF and CPD 5-mediated signal transduction were studied.. DNA content was measured by Hoechst fluorescent assay. Phosphorylated proteins were described with Western blots or two-dimensional electrophoresis.. CPD 5-induced EGFR phosphorylation was functional to stimulate Ras pathway. However, CPD 5-mediated extracellular signal-regulated kinase (ERK) phosphorylation was not antagonized by inhibition of upstream activation with PD153035. CPD 5 inhibited ERK dephosphorylation in cell lysate, suggesting that ERK phosphorylation by CPD 5 was depending on kinase activity and phosphatase inhibition. Two-dimensional electrophoresis showed extra phospho ERK spot, which was indicated to have close association with CPD 5-induced growth inhibition, since U0126 antagonized growth inhibition and appearance of this spot.. The turning point of EGFR pathway was proved to have close association with the expressed level of phosphorylated ERK. ERK phosphorylation was suggested to play a critical role in growth factor-induced signal transduction.

Topics: Antineoplastic Agents; Antioxidants; Carcinoma, Hepatocellular; Cell Division; Humans; JNK Mitogen-Activated Protein Kinases; Liver Neoplasms; Mitogen-Activated Protein Kinases; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Phosphorylation; ras Proteins; Signal Transduction; Sulfhydryl Compounds; Tumor Cells, Cultured; Vitamin K

We recently found that a thioether analog of K vitamin (Cpd 5) inhibited the activity of protein-tyrosine phosphatases (PTPases) and induced protein-tyrosine phosphorylation in a human hepatoma cell line (Hep3B). We have now examined the structural requirements for induction of protein-tyrosine phosphorylation and PTPase inhibition by several K vitamin analogs. Thioether analogs with sulfhydryl arylation capacity, especially those with a hydroxy (Cpd 5) or a methoxy group at the end of the side chain, induced protein-tyrosine phosphorylation, but non-arylating analogs, such as those with an all-carbon or O-ether side chain, did not. Among the receptor-tyrosine kinases, epidermal growth factor receptors were tyrosine-phosphorylated by treatment with thioether analogs, whereas insulin and hepatocyte growth factor receptors were not. An increase in tyrosine-phosphorylated ERK2 mitogen-activated protein kinase was also observed. The activity of purified T cell PTPase was inhibited only by the thioether analogs, but not by non-arylating analogs. Furthermore, the epidermal growth factor receptor dephosphorylation activity of Hep3B cell lysates was inhibited by Cpd 5 treatment. A similar induction of protein-tyrosine phosphorylation by Cpd 5 was seen in other human hepatoma cell lines together with growth inhibition. However, one cell line (HepG2), which was relatively resistant to growth inhibition by Cpd 5, did not increase its phosphorylation levels upon Cpd 5 treatment. These results suggest that cell growth inhibition by thioether analogs is closely associated with inhibition of PTPases by sulfhydryl arylation and with tyrosine phosphorylation of selected proteins.

Topics: Carcinoma, Hepatocellular; Cell Division; Dose-Response Relationship, Drug; Electrophoresis, Gel, Two-Dimensional; ErbB Receptors; Humans; Isoenzymes; Mercaptoethanol; Naphthoquinones; Phospholipase C gamma; Phosphorylation; Protein Tyrosine Phosphatases; T-Lymphocytes; Time Factors; Tumor Cells, Cultured; Type C Phospholipases; Vanadates; Vitamin K

In present study we studied the cytotoxic effects of beta-lapachone, a potent anticancer drug, on the human hepatoma cell line (HepA2) under serum-free condition. Most cells died after 2 microM beta-lapachone addition at 48 hours. No apoptotic characteristics of DNA ladder was documented by agarose DNA electrophoresis. The blockage of cell cycle at S phase and unscheduled DNA synthesis were demonstrated by flow cytometric analysis and anti-bromodeoxyuridine immunocytochemistry. Ultrastructural observation showed that the swollen mitochondria, dilatation and vesiculation of rER and proliferation of peroxisome-like granules appeared within the cytoplasm of HepA2 cells following drug treatment. Using enzyme cytochemistry, both peroxidase and acid phosphatase activities but not catalase activity were localised in these peroxisome-like granules. Therefore, these results suggested that (a) beta-lapachone has a novel cytotoxic effect on human hepatoma cell; (2) beta-lapachone induces the interruption of the cell cycle and unscheduled DNA synthesis in HepA2 cells; and (3) beta-lapachone promotes the proliferation of peroxisome-like granules containing peroxidase and acid phosphatase activities without evidence of catalase activity in hepatoma cell line.

Topics: Antibiotics, Antineoplastic; Apoptosis; Carcinoma, Hepatocellular; Cytoplasmic Granules; DNA Replication; Humans; Liver Neoplasms; Microbodies; Naphthoquinones; S Phase; Tumor Cells, Cultured

We have shown that a synthetic vitamin K analog, 2-(2-mercaptoethanol)-3-methyl-1,4-naphthoquinone or compound 5 (Cpd 5), potently inhibits cell growth and suggested that the analog exerts its effects mainly via sulfhydryl arylation rather than redox cycling. Since protein-tyrosine phosphatases (PTPases), which have pivotal roles in many cellular functions, have a critical cysteine in their active site, we have proposed PTPases as likely targets for Cpd 5. To test this hypothesis, we examined the effects of Cpd 5 on protein tyrosine phosphorylation of cellular proteins and on the activity of PTPases. We found that Cpd 5 rapidly induced protein tyrosine phosphorylation in a human hepatocellular carcinoma cell line (Hep3B) at growth inhibitory doses, and the effect was blocked by thiols but not by non-thiol antioxidants or tyrosine kinase inhibitors. Cpd 5 inhibited PTPase activity, which was also significantly antagonized by reduced glutathione. Furthermore, the well studied PTPase inhibitor orthovanadate also induced protein tyrosine phosphorylation and growth inhibition in Hep3B cells. These results suggest that inhibition of cellular PTPases by sulfhydryl arylation and subsequent perturbation of protein tyrosine phosphorylation may be involved in the mechanisms of Cpd 5-induced cell growth inhibition.

Topics: Carcinoma, Hepatocellular; Catechols; Cell Division; Cell Line; Enzyme Inhibitors; Epidermal Growth Factor; Genistein; Humans; Kinetics; Liver Neoplasms; Mercaptoethanol; Naphthoquinones; Nitriles; Phosphorylation; Phosphotyrosine; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Sulfhydryl Compounds; Tumor Cells, Cultured; Tyrphostins; Vanadates; Vitamin K

Ookinete formation from mature Plasmodium berghei gametocytes in vitro was partially inhibited by 0.05-0.1 microM atovaquone and almost totally blocked at a concentration of 0.25 microM. Microgametocyte exflagellation was not affected by atovaquone at concentrations up to 300 microM. Ookinete formation was also inhibited in culture when addition of 0.20 microM atovaquone was delayed by 4 hr, by which time DNA replication was likely to have been completed. Inhibition of ookinete formation by atovaquone was not reversed by orotic acid. Plasmodium berghei-infected Anopheles stephensi mosquitoes were fed a second blood meal 4, 7, 14, and 20 days postinfection (p.i.) from mice that had been treated with atovaquone or control diluent 8 hr previously. Atovaquone blood feeds on day 4 reduced oocyst numbers on days 6-12, although sporozoite numbers in the thorax and abdomen on day 20 were not significantly reduced. Blood feeds on day 7 slowed oocyst growth, blood feeds on day 14 did not significantly reduce sporozoite numbers, and feeds to mosquitoes on day 20 p.i. had no effect on transmission to naive mice. Sporozoite invasion of human hepatoma cells was unaffected by the presence of atovaquone.

Topics: Animals; Anopheles; Antimalarials; Atovaquone; Carcinoma, Hepatocellular; Culture Media; Flagella; Insect Vectors; Liver Neoplasms; Mice; Naphthoquinones; Plasmodium berghei; Tumor Cells, Cultured

Topics: Animals; Body Weight; Carcinogens; Carcinoma, Hepatocellular; Chemical and Drug Induced Liver Injury; Chlorine; Diet; Dose-Response Relationship, Drug; Female; Lethal Dose 50; Liver; Liver Cirrhosis; Liver Neoplasms; Lung Neoplasms; Male; Mice; Mice, Inbred Strains; Mycotoxins; Naphthoquinones; Necrosis; Oryza; Penicillium; Peptides, Cyclic; Sex Factors

Topics: Animals; Animals, Newborn; Carcinogens; Carcinoma, Hepatocellular; Dogs; Female; Fibroma; Fibrosarcoma; Granuloma; Hydroxylation; Liver Neoplasms; Lymphoma, Non-Hodgkin; Male; Mice; Naphthalenes; Naphthoquinones; Neoplasms, Experimental; Nitroso Compounds; Urinary Bladder Neoplasms; Urine

Topics: Animals; Ascites; Carcinoma, Hepatocellular; Coenzymes; Electron Transport Complex II; Liver Neoplasms; Liver Neoplasms, Experimental; Mechlorethamine; Naphthoquinones; Neoplasms, Experimental; Oxidoreductases; Rats; Succinate Dehydrogenase; Succinates; Succinic Acid; Tetrazolium Salts; Ubiquinone; Vitamin K; Vitamin K 3