nsc-74859 and Carcinoma--Hepatocellular

Hepatocellular carcinoma (HCC) is a fatal disease with increasing morbidity and poor prognosis due to surgical recurrence and metastasis. Moreover, the molecular mechanism of HCC progression remains unclear. Although the role of p120-catenin (p120ctn) in liver cancer is well studied, the effects of secreted p120ctn transported by exosomes are less understood. Here, we show that p120ctn in exosomes secreted from liver cancer cells suppresses HCC cell proliferation and metastasis and expansion of liver cancer stem cells (CSCs). Mechanically, exosome p120ctn inhibits HCC cell progression via the STAT3 pathway, and the STAT3 inhibitor S3I-201 abolishes the observed effects on growth, metastasis, and self-renewal ability between exosome p120ctn-treated HCC cells and control cells. Taken together, we propose that p120ctn-containing exosomes derived from cancer cells inhibit the progression of liver cancer and may offer a new therapeutic strategy.

Topics: Aminosalicylic Acids; Benzenesulfonates; Carcinoma, Hepatocellular; Catenins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Delta Catenin; Exosomes; Humans; Liver Neoplasms; Neoplasm Metastasis; Neoplastic Stem Cells; STAT3 Transcription Factor

Hepatocellular carcinoma (HCC) is a refractory malignancy with a high mortality and increasing worldwide incidence rates, including the United States and central Europe. In this study, we demonstrate that a specific inhibitor of signal transducer and activator of transcription 3 (STAT3), NSC74859, efficiently reduces HCC cell proliferation and can be successfully combined with oncolytic virotherapy using vesicular stomatitis virus (VSV). The potential benefits of this combination treatment are strengthened by the ability of NSC74859 to protect primary hepatocytes and nervous system cells against virus-induced cytotoxicity, with an elevation of the VSV maximum tolerated dose in mice. Hereby we propose a strategy for improving the current regimen for HCC treatment and seek to further explore the molecular mechanisms underlying selective oncolytic specificity of VSV.

Topics: Aminosalicylic Acids; Animals; Antineoplastic Agents; Benzenesulfonates; Carcinoma, Hepatocellular; Combined Modality Therapy; Humans; Liver Neoplasms; Male; Mice; Oncolytic Virotherapy; Rats; STAT3 Transcription Factor; Vesicular stomatitis Indiana virus

Hepatocellular carcinoma (HCC) is one of the most common cancers with a high mortality rate. Constitutive activation of STAT3 is found in various types of tumors, including HCC. In addition, suppressors of cytokine signaling 3 (SOCS3) signals for negative feedback to STATs, and is found to be inversely correlated with STAT3 expression. However, the exact role of SOCS3 in the tumorigenesis and progression of HCC is not fully understood. In this study we intended to show that SOCS3 inhibition promotes proliferation, migration, and invasion of HCC cells. HepG2, a human HCC cell line, was grown with SOCS3 siRNA or negative control (NC) transfection to assess the involvement of SOCS3 in cell proliferation, migration, and invasion by MTT, migration, and invasion assays, respectively. Western blot analysis was performed to examine the expression of STAT3, SOCS3, c-myc, matrix metalloproteinase (MMP)-2, and MMP-9 after transfection with either SOCS3 or NC siRNAs. A diethylnitrosamine (DEN)-induced HCC mouse model was assessed with or without injection of NSC 74859, a STAT3 inhibitor, to show accompanied changes among the expressions of STAT3, SOCS3, c-myc, MMP-2, and MMP-9. Inhibition of SOCS3 expression promoted the proliferation, migration, and invasion of HepG2 cells and increased the expression of c-myc, MMP-2, and MMP-9. HCC tumors developed in mice by DEN-induction with administration of NSC 74859 resulted in decreased expression of c-myc, MMP-2, and MMP-9, but not SOCS3. Loss of SOCS3 increased tumor growth, migration, and invasion and resulted in accompanied changes in expression of STAT3 and its target oncoproteins.

Topics: Aminosalicylic Acids; Animals; Benzenesulfonates; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Hep G2 Cells; Humans; Liver Neoplasms; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice, Inbred C57BL; Neoplasm Invasiveness; Proto-Oncogene Proteins c-myc; Random Allocation; STAT3 Transcription Factor; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins

Cetuximab [an epidermal growth factor receptor (EGFR) inhibitor], which was shown to be effective in rectal and non-small cell lung cancers (NSCLCs), was only modestly effective in clinical trials of hepatocellular carcinoma (HCC). STAT3, which is thought to be a determinant of HCC sensitivity to antitumour drugs, may be involved.. To evaluate the efficacy of combination therapy using cetuximab and NSC 74859 (a novel STAT3 inhibitor) in EGFR and STAT3 overexpressing hepatoma cells.. Hepatoma cell lines were treated with cetuximab, NSC 74859 or a combination of both drugs. Efficacy of treatment was evaluated by determining cell viability using MTT assays and proliferation by cell counting. Expression and activation of STAT3 were determined using Western blot analysis. We evaluated the role of STAT3 in single and combination therapy using siRNA-mediated knock-down of STAT3 or STAT3 overexpression strategies.. HepG2 and Huh-7 cells, which had lower levels of pSTAT3 than SK-HEP1 cells, were more sensitive to cetuximab treatment when compared with SK-HEP1 cells. Although none of these cell lines was sensitive to NSC 74859 alone, NSC 74859 potentiated the antiproliferative effect of cetuximab in all three cell lines. siRNA knock-down of STAT3 increased the sensitivity of these cell lines to cetuximab, whereas STAT3 overexpression antagonized these effects.. Enhanced growth inhibition in hepatoma cells treated with both NSC 74859 and cetuximab suggests that cetuximab resistance is probably mediated via STAT3. Combination therapy using both inhibitors of EGFR and STAT3 signalling warrants further investigation under in vivo condition.

Topics: Aminosalicylic Acids; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Benzenesulfonates; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cetuximab; Drug Screening Assays, Antitumor; Drug Synergism; Hepatocytes; Humans; Liver Neoplasms; STAT3 Transcription Factor; Tetrazolium Salts; Thiazoles; Transfection

Doxorubicin-based therapy is not effective for the treatment of hepatocellular carcinomas (HCCs), which often undergo epithelial-mesenchymal transition (EMT) during tumor progression. Activation of signal transducer and activator of transcription 3 (STAT3) is associated with chemosensitivity and may contribute to EMT during HCC chemotherapy. Low doses of NSC 78459 (a novel STAT3 inhibitor) have little effect on HCC cell proliferation, but efficiently inhibit STAT3. HuH-7, Hep3B, and HepG2 cells, with epithelial phenotypes, show significantly enhanced doxorubicin cytotoxicity following co-treatment with NSC 74859, whereas mesenchymal SNU-449 cells show no such enhancement. NSC 74859 inhibits STAT3 activity and suppressed doxorubicin-induced EMT in epithelial HCC cells. siRNA-mediated STAT3 knockdown resulted in EMT inhibition, which led to attenuation of NSC 74859-mediated chemosensitivity. Our data indicate NSC 74859 co-administration enhances doxorubicin cytotoxicity by inhibiting STAT3 in epithelial HCC cells. STAT3 deactivation and associated EMT attenuation contribute to the synergistic anti-tumor effects of combined NSC 74859/doxorubicin therapy.

Topics: Aminosalicylic Acids; Antibiotics, Antineoplastic; Antineoplastic Agents; Benzenesulfonates; Cadherins; Carcinoma, Hepatocellular; Cell Line, Tumor; Doxorubicin; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Liver Neoplasms; Nuclear Proteins; RNA Interference; RNA, Small Interfering; STAT3 Transcription Factor; Twist-Related Protein 1; Vimentin

Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor ubiquitously expressed in different cell types. STAT3 plays an essential role in cell survival, proliferation, and differentiation. Aberrantly hyper-activated STAT3 signaling in cancer cells and in the tumor microenvironment has been detected in a wide variety of human cancers and is considered an important factor for cancer initiation, development, and progression. However, the role of STAT3 activation in monocytes in the development of HCC has not been well understood.. Immunohistochemical analysis of phosphorylated STAT3 was performed on tissue microarray from HCC patients. Using a co-culture system in vivo, HCC cell growth was determined by the MTT assay. In vivo experiments were conducted with mice given diethylinitrosamine (DEN), which induces HCC was used to investigate the role of STAT3 expression in monocytes on tumor growth. Real-time PCR was used to determine the expression of cell proliferation and cell arrest associated genes in the tumor and nontumor tissue from liver.. Phosphorylated STAT3 was found in human hepatocellular carcinoma tissue samples and was expressed in tumor cells and also in monocytes. Phosphorylated STAT3 expression in monocyte was significantly correlated to advanced clinical stage of HCC and a poor prognosis. Using a co-culture system in vivo, monocytes promoted HCC cell growth via the IL-6/STAT3 signaling pathway. The STAT3 inhibitor, NSC 74859, significantly suppressed tumor growth in vivo in mice with diethylinitrosamine (DEN)-induced HCC. In this animal model, blockade of STAT3 with NSC 74859 induced tumor cell apoptosis, while inhibiting both tumor cells and monocytes proliferation. Furthermore, NSC 74859 treatment suppressed cancer associated inflammation in DEN-induce HCC.. Our data suggest constitutively activated STAT3 monocytes promote liver tumorigenesis in clinical patients and animal experiments. Thus, STAT3 in tumor infiltrating inflammatory cells may an attractive target for liver cancer therapy.

Topics: Aminosalicylic Acids; Analysis of Variance; Animals; Apoptosis; Benzenesulfonates; Carcinogens; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Diethylnitrosamine; Disease Models, Animal; Disease Progression; Humans; Interleukin-6; Liver Neoplasms, Experimental; Mice; Monocytes; RNA, Ribosomal, 18S; STAT3 Transcription Factor

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide, with few effective therapeutic options for advanced disease. At least 40% of HCCs are clonal, potentially arising from STAT3+, NANOG+ and OCT3/4+ liver progenitor/stem cell transformation, along with inactivation of transforming growth factor-beta (TGF-beta) signaling. Here we report significantly greater signal transducer and activator of transcription 3 (STAT3) and tyrosine phosphorylated STAT3 in human HCC tissues (P<0.0030 and P<0.0455, respectively) than in human normal liver. Further, in HCC cells with loss of response to TGF-beta, NSC 74859, a STAT3-specific inhibitor, markedly suppresses growth. In contrast, CD133(+) status did not affect the response to STAT3 inhibition: both CD133(+) Huh-7 cells and CD133(-) Huh-7 cells are equally sensitive to NSC 74859 treatment and STAT3 inhibition, with an IC(50) of 100 muM. Thus, the TGF-beta/beta2 spectrin (beta2SP) pathway may reflect a more functional 'stem/progenitor' state than CD133. Furthermore, NSC 74859 treatment of Huh-7 xenografts in nude mice significantly retarded tumor growth, with an effective dose of only 5 mg/kg. Moreover, NSC 74859 inhibited tyrosine phosphorylation of STAT3 in HCC cells in vivo. We conclude that inhibiting interleukin 6 (IL6)/STAT3 in HCCs with inactivation of the TGF-beta/beta2SP pathway is an effective approach in management of HCCs. Thus, IL6/STAT3, a major signaling pathway in HCC stem cell renewal and proliferation, can provide a novel approach to the treatment of specific HCCs.

Topics: AC133 Antigen; Aminosalicylic Acid; Aminosalicylic Acids; Animals; Antigens, CD; Apoptosis; Benzenesulfonates; Blotting, Western; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Colony-Forming Units Assay; Female; Glycoproteins; Humans; Immunoenzyme Techniques; Liver Neoplasms; Mice; Mice, Nude; Peptides; Phosphorylation; STAT3 Transcription Factor; Transforming Growth Factor beta; Xenograft Model Antitumor Assays

Topics: Aminosalicylic Acids; Benzenesulfonates; Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Quinolines; Signal Transduction; STAT3 Transcription Factor; Transforming Growth Factor beta