RESUMO
Non-small lung cancer (NSCLC) is the most common cancer in the world. The epidermal growth factor receptor (EGFR) gene is mutated in approximately 10% of lung cancer cases in the US and 50% of lung cancer in Asia. The representative target therapeutic agent, erlotinib (EGFR tyrosine kinase inhibitor; EGFR TKI), is effective in inactivating EGFR in lung cancer patients. However, approximately 50-60% of patients are resistant to EGFR TKI. These populations are associated with the EGFR mutation. To overcome resistance to EGFR TKI, we discovered a JAK1 inhibitor, CJ14939. We investigated the efficacy of CJ14939 in human NSCLC cell lines in vitro and in vivo. Our results showed that CJ14939 induced the inhibition of cell growth. Moreover, we demonstrated that combination treatment with erlotinib and CJ14939 induced cell death in vitro and inhibited tumor growth in vivo. In addition, we confirmed the suppression of phosphorylated EGFR, JAK1, and Stat3 expression in erlotinib and CJ14939-treated human NSCLC cell lines. Our results provide evidence that JAK inhibition overcomes resistance to EGFR TKI in human NSCLCs.
Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cloridrato de Erlotinib/farmacologia , Janus Quinase 1/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Antineoplásicos/química , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Cloridrato de Erlotinib/química , Feminino , Humanos , Janus Quinase 1/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Estrutura Molecular , Mutação , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
BACKGROUND: Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signalling pathway and are attractive targets for cancer therapy. These agents continue to be investigated in KRAS mutant colon cancer but are met with significant resistance. Clinical investigations have demonstrated that these strategies are not well tolerated by patients. METHODS: We investigated a biomarker of response for MEK inhibition in KRAS mutant colon cancers by LC-MS/MS analysis. We tested the MEK inhibitor in PIK3CA wild(wt) and mutant(mt) colon cancer cells. In addition, we tested the combinational effects of MEK and TNKS inhibitor in vitro and in vivo. RESULTS: We identified ß-catenin, a key mediator of the WNT pathway, in response to MEK inhibitor. MEK inhibition led to a decrease in ß-catenin in PIK3CA wt colon cancer cells but not in mt. Tumour regression was promoted by combination of MEK inhibition and NVP-TNS656, which targets the WNT pathway. Furthermore, inhibition of MEK promoted tumour regression in colon cancer patient-derived xenograft models expressing PIK3CA wt. CONCLUSIONS: We propose that inhibition of the WNT pathway, particularly ß-catenin, may bypass resistance to MEK inhibition in human PIK3CA mt colon cancer. Therefore, we suggest that ß-catenin is a potential predictive marker of MEK inhibitor resistance.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/genética , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 3/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , beta Catenina/metabolismo , Acetamidas/farmacologia , Animais , Biomarcadores Farmacológicos/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias do Colo/metabolismo , Farmacorresistência Viral , Humanos , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 3/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Pirimidinonas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , beta Catenina/antagonistas & inibidoresRESUMO
Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is a viral protein expressed in all EBV-infected cells that induces malignant transformation. EBNA1 is reported to contribute to tumor progression through an increase in reactive oxygen species via nicotinamide adenine dinucleotide phosphate oxidase. However, the underlying molecular mechanism of EBNA1-induced ROS accumulation in gastric cancer is poorly understood. Here, we demonstrated that miR34a regulation by EBNA1 determined cell fate in EBV-infected gastric cancer cells. ROS content and NOX2 expression were higher in EBNA1-expressing SNU719 cells than in EBNA1-nonexpressing SNU638 cells. Downregulation of NOX2 using siRNA technology in SNU719 cells decreased cell viability and ROS content. Regulation of EBNA1 expression in EBV-associated gastric cancers modulated NOX2 expression, ROS content and cell viability. We also showed that upregulation of NOX2 by EBNA1 was mediated by downregulating miRNA34a. Finally, overexpression of miR34a in EBNA1-expressing SNU719 cells induced typical apoptosis, suggesting that reactivation of miR34a in EBNA1-expressing gastric cancer cells could be a strategy for treatment of EBV-infected gastric cancer cells.
Assuntos
Sobrevivência Celular , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/fisiologia , MicroRNAs/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Linhagem Celular Tumoral , Humanos , Transdução de Sinais , Neoplasias Gástricas/patologiaRESUMO
Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is an oncoviral protein that plays a pivotal role in EBV-induced oncogenic transformation. The function of LMP1 in EBV-induced oncogenesis has been well studied. However, the molecular mechanisms underlying LMP1 protein stability remain poorly understood. In this study, we found that ribosomal protein s27a (RPS27a) regulates LMP1 stability by a tandem affinity purification analysis. RPS27a interacts directly with LMP1 in vitro and in vivo. Furthermore, overexpression of RPS27a increases the half-life of LMP1 in 293T cells, whereas downregulation of RPS27a using lentiviral shRNA technology accelerates the decrease in LMP1 protein level in EBV-transformed B cells. We show that LMP1 ubiquitination via the proteasome is completely inhibited by overexpression of RPS27a. RPS27a also enhances LMP1-mediated proliferation and invasion, suggesting that RPS27a interacts with LMP1 and stabilizes it by suppressing proteasome-mediated ubiquitination. These results suggest that RSP27a could be a potential target in EBV-infected LMP1-positive cancer cells.
Assuntos
Transformação Celular Neoplásica/genética , Herpesvirus Humano 4/genética , Interações Hospedeiro-Patógeno , Proteínas Ribossômicas/genética , Ubiquitinas/genética , Proteínas da Matriz Viral/genética , Animais , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Cães , Regulação da Expressão Gênica , Células HEK293 , Meia-Vida , Herpesvirus Humano 4/crescimento & desenvolvimento , Herpesvirus Humano 4/metabolismo , Humanos , Células Madin Darby de Rim Canino , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Estabilidade Proteica , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Ribossômicas/antagonistas & inibidores , Proteínas Ribossômicas/metabolismo , Transdução de Sinais , Ubiquitinação , Ubiquitinas/antagonistas & inibidores , Ubiquitinas/metabolismo , Proteínas da Matriz Viral/metabolismoRESUMO
The epithelial to mesenchymal transition (EMT), a hallmark of chronic kidney disease, is a key event in the conversion from tubular epithelial cells to myofibroblasts in renal fibrosis. Epstein-Barr virus (EBV) is a γ-herpes oncovirus associated with chronic kidney disease. However, the relationship between EBV and the EMT process in renal tubular epithelial cells is not well understood. Among EBV-latent genes, EBV-encoded latent membrane protein 1 (LMP1) induces EMT by regulating a variety of molecules in EBV-induced oncogenic transformation. In this study, we investigated EBV-encoded LMP1 and EMT process markers in human proximal tubule epithelial cell line HK-2. LMP1 overexpression induces cell morphological changes via the epithelial to mesenchymal process in HK-2 cells, and these changes accelerate cell proliferation, cell motility, and invasion. Furthermore, VSIG4 upregulation by EBV-LMP1 induced LMP1-mediated EMT, cell motility, and invasion. VSIG4 upregulation by LMP1 was regulated at the transcriptional level via the NF-kB signaling axis. These results suggest that EBV-encoded LMP1 regulates EMT through the NF-kB-VSIG4 axis in HK-2 cells, and VSIG4 is a potential target in EBV-induced chronic kidney diseases.
Assuntos
Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Túbulos Renais/metabolismo , NF-kappa B/metabolismo , Receptores de Complemento/genética , Proteínas da Matriz Viral/metabolismo , Animais , Células Cultivadas , Cães , Humanos , Túbulos Renais/citologia , Células Madin Darby de Rim Canino , Receptores de Complemento/metabolismoRESUMO
YM155, which blocks the expression of survivin, a member of the inhibitor of apoptosis (IAP) family, induces cell death in a variety of cancer types, including prostate, bladder, breast, leukemia, and non-small lung cancer. However, the mechanism underlying gastric cancer susceptibility and resistance to YM155 is yet to be specified. Here, we demonstrate that cIAP1 stability dictates resistance to YM155 in human gastric cancer cells. Treatment of human gastric cancer cells with YM155 differentially induced cell death dependent on the stability of cIAP1 as well as survivin. Transfection with cIAP1 expression plasmids decreased cell sensitivity to YM155, whereas knockdown of endogenous cIAP1 using RNA interference enhanced sensitivity to YM155. In addition, double knockdown of survivin and cIAP1 significantly induced cell death in the YM155-resistant cell line, MKN45. We also showed that YM155 induced autoubiquitination and proteasome-dependent degradation of cIAP1. Surprisingly, survivin affected the stability of cIAP1 through binding, contributing to cell sensitivity to YM155. Thus, our findings reveal that YM155 sensitizes human gastric cancer cells to apoptotic cell death by degrading cIAP1, and furthermore, cIAP1 in gastric cancer cells may act as a PD marker for YM155 treatment.
Assuntos
Antineoplásicos/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Imidazóis/farmacologia , Proteínas Inibidoras de Apoptose/genética , Naftoquinonas/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Proteínas Inibidoras de Apoptose/metabolismo , Ligação Proteica , Estabilidade Proteica , Proteólise , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Survivina , UbiquitinaçãoRESUMO
Pancreatic cancer is one of the most lethal cancers and remains a major unsolved health problem. Less than 20 % of patients are surgical candidates, and the median survival for non-resected patients is approximately 3 to 4 months. Despite the existence of many conventional cancer therapies, few targeted therapies have been developed for pancreatic cancer. Combination therapy using erlotinib and gemcitabine is an approved standard chemotherapy for advanced pancreatic cancer, but it has marginal therapeutic benefit. To try to improve the therapeutic outlook, we studied the efficacy of another combination treatment and the relevance to E-cadherin in human pancreatic cancer cells. We treated two human pancreatic cancer cell lines with the histone deacetylase inhibitor (HDACi) SAHA. Interestingly, in these Panc-1 and Capan1 cells, we observed that the expression levels of E-cadherin and phosphorylated EGFR were gradually upregulated after treatment with SAHA. Furthermore, these cells underwent induced cell death after exposure to the combination treatment of SAHA and erlotinib. In Panc-1 cells, overexpression of E-cadherin activated the phosphorylation of EGFR and increased the cell sensitivity to erlotinib. In Capan1 cells, knocking down E-cadherin decreased the expression of phosphorylated EGFR, and these cells did not respond to erlotinib. Therefore, we demonstrated the efficacy of the combined treatment with SAHA and erlotinib in human pancreatic cancer cells, and we determined that the increased efficacy was due, at least in part, to the effects of SAHA on the expression of E-cadherin. Our studies suggest that E-cadherin may be a potent biomarker for pancreatic cancer.
Assuntos
Caderinas/genética , Receptores ErbB/biossíntese , Cloridrato de Erlotinib/administração & dosagem , Inibidores de Histona Desacetilases/administração & dosagem , Ácidos Hidroxâmicos/administração & dosagem , Neoplasias Pancreáticas/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Caderinas/biossíntese , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Vorinostat , GencitabinaRESUMO
OBJECTIVES: This study investigates the clinical significance of the gene encoding AP-2ε (TFAP2E) in colorectal cancer (CRC) patients undergoing curative resection. METHODS: A single-institution cohort of 248 patients who underwent curative resection of stage I/II/III CRCs between March and December 2004 was enrolled, and 193 patients whose tumors were available for the determination of the TFAP2E methylation status were included in the analysis. RESULTS: TFAP2E hypermethylation was detected in 112 patients (58%) and was significantly associated with distally located CRCs, low pathologic T stage (T1/T2), and stage I tumors. After a median follow-up of 86.3 months, the patients with TFAP2E hypermethylation tended to show better relapse-free survival (RFS) and overall survival (OS) than the patients with TFAP2E hypomethylation (5-year RFS rate: 90 vs. 80%, p = 0.063; 6-year OS rate: 88 vs. 80%, p = 0.083). Multivariate analysis showed that the pathologic nodal stage and TFAP2E methylation status were independent prognostic factors for RFS and OS, and they remained significant factors in the subgroup analysis that included 154 patients with stage II/III CRCs who had received adjuvant chemotherapy. CONCLUSIONS: TFAP2E hypermethylation is associated with good clinical outcomes and may be considered as an independent prognostic factor in patients with curatively resected CRCs.
Assuntos
Neoplasias Colorretais/genética , Metilação de DNA , Fator de Transcrição AP-2/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos ProporcionaisRESUMO
The MET proto-oncogene product, which is the receptor for hepatocyte growth factor (HGF), has been implicated in tumorigenesis and metastatic progression. Point mutations in MET lead to the aberrant activation of the receptor in many types of human malignancies, and the deregulated activity of MET has been correlated with tumor growth, invasion, and metastasis. MET has therefore attracted considerable attention as a potential target in anticancer therapy. Here, we report that a novel MET kinase inhibitor, NPS-1034, inhibits various constitutively active mutant forms of MET as well as HGF-activated wild-type MET. NPS-1034 inhibited the proliferation of cells expressing activated MET and promoted the regression of tumors formed from such cells in a mouse xenograft model through anti-angiogenic and pro-apoptotic actions. NPS-1034 also inhibited HGF-stimulated activation of MET signaling in the presence or absence of serum. Furthermore, when tested on 27 different MET variants, NPS-1034 inhibited 15 of the 17 MET variants that exhibited autophosphorylation with nanomolar potency; only the F1218I and M1149T variants were not inhibited by NPS-1034. Notably, NPS-1034 inhibited three MET variants that are resistant to the MET inhibitors SU11274, NVP-BVU972, and PHA665752. Together, these results suggest that NPS-1034 can be used as a potent therapeutic agent for human malignancies bearing MET point mutations or expressing activated MET.
Assuntos
Antineoplásicos/farmacologia , Compostos Heterocíclicos com 2 Anéis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Pirazóis/farmacologia , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Fator de Crescimento de Hepatócito/farmacologia , Compostos Heterocíclicos com 2 Anéis/uso terapêutico , Humanos , Camundongos Mutantes , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Pirazóis/uso terapêutico , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Members of the RAF family (ARAF, BRAF, and CRAF/RAF-1) are involved in a variety of cellular activities, including growth, survival, differentiation, and transformation. An oncogene encodes BRAF, the function of which is linked to MEK activation. BRAF is the most effective RAF kinase in terms of induction of MEK/ERK activity. However, the mechanisms involved in BRAF regulation remain unclear. In the present work, we used a tandem affinity purification approach to show that RNF149 (RING finger protein 149) interacts with wild-type BRAF. The latter protein is a RING domain-containing E3 ubiquitin ligase involved in control of gene transcription, translation, cytoskeletal organization, cell adhesion, and epithelial development. We showed that RNF149 bound directly to the C-terminal kinase-containing domain of wild-type BRAF and induced ubiquitination, followed by proteasome-dependent degradation, of the latter protein. Functionally, RNF149 attenuated the increase in cell growth induced by wild-type BRAF. However, RNF149 did not bind to mutant BRAF or induce ubiquitination thereof. Thus, we show that RNF149 is an E3 ubiquitin ligase active on wild-type BRAF.
Assuntos
Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular , Células HCT116 , Células HEK293 , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas B-raf/genética , Interferência de RNA , Sinvastatina/farmacologia , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/efeitos dos fármacosRESUMO
Recepteur d'origine nantais (RON, MST1R) is a single-span transmembrane receptor tyrosine kinase (RTK) aberrantly expressed in numerous cancers, including various solid tumors. How naturally occurring splicing isoforms of RON, especially those which are constitutively activated, affect tumorigenesis and therapeutic response, is largely unknown. Here, we identified that presence of activated RON could be a possible factor for the development of resistance against anti-EGFR (cetuximab) therapy in colorectal cancer patient tissues. Also, we elucidated the roles of three splicing variants of RON, RON Δ155, Δ160, and Δ165 as tumor drivers in cancer cell lines. Subsequently, we designed an inhibitor of RON, WM-S1-030, to suppress phosphorylation thereby inhibiting the activation of the three RON variants as well as the wild type. Specifically, WM-S1-030 treatment led to potent regression of tumor growth in solid tumors expressing the RON variants Δ155, Δ160, and Δ165. Two mechanisms for the RON oncogenic activity depending on KRAS genotype was evaluated in our study which include activation of EGFR and Src, in a trimeric complex, and stabilization of the beta-catenin. In terms of the immunotherapy, WM-S1-030 elicited notable antitumor immunity in anti-PD-1 resistant cell derived mouse model, likely via repression of M1/M2 polarization of macrophages. These findings suggest that WM-S1-030 could be developed as a new treatment option for cancer patients expressing these three RON variants.
Assuntos
Neoplasias , Animais , Camundongos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Fosforilação , Isoformas de Proteínas/genéticaRESUMO
Significant improvement in targeted therapy for colorectal cancer (CRC) has occurred over the past few decades since the approval of the EGFR inhibitor cetuximab. However, cetuximab is used only for patients possessing the wild-type oncogene KRAS, NRAS, and BRAF, and even most of these eventually acquire therapeutic resistance, via activation of parallel oncogenic pathways such as RAS-MAPK or PI3K/Akt/mTOR. The two aforementioned pathways also contribute to the development of therapeutic resistance in CRC patients, due to compensatory and feedback mechanisms. Therefore, combination drug therapies (versus monotherapy) targeting these multiple pathways may be necessary for further efficacy against CRC. In this study, we identified PIK3CA mutant (PIK3CA MT) as a determinant of resistance to SMI-4a, a highly selective PIM1 kinase inhibitor, in CRC cell lines. In CRC cell lines, SMI-4a showed its effect only in PIK3CA wild type (PIK3CA WT) cell lines, while PIK3CA MT cells did not respond to SMI-4a in cell death assays. In vivo xenograft and PDX experiments confirmed that PIK3CA MT is responsible for the resistance to SMI-4a. Inhibition of PIK3CA MT by PI3K inhibitors restored SMI-4a sensitivity in PIK3CA MT CRC cell lines. Taken together, these results demonstrate that sensitivity to SMI-4a is determined by the PIK3CA genotype and that co-targeting of PI3K and PIM1 in PIK3CA MT CRC patients could be a promising and novel therapeutic approach for refractory CRC patients.
Assuntos
Neoplasias do Colo , Fosfatidilinositol 3-Quinases , Humanos , Cetuximab/farmacologia , Cetuximab/uso terapêutico , Fosfatidilinositol 3-Quinases/genética , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Biomarcadores , Classe I de Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-pim-1/genéticaRESUMO
BACKGROUND/AIM: Colorectal cancer is reported to have the highest mortality rate among human malignancies. Although many research results for the treatment of colorectal cancer have been reported, there is no suitable treatment when resistance has developed. Therefore, it is necessary to develop new therapeutic agents. Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling plays an essential role in cell differentiation, proliferation, and survival. Abnormal activation of the JAK/STAT signaling pathway, by gene mutation or amplification, may induce cancer development, and sustained JAK/STAT activation is involved in chemoresistance. While many therapeutic agents have been developed to treat colon cancer, there remains no drug to overcome resistance to chemotherapies. The purpose of this study was to determine the potential of CJ14939 as a novel JAK inhibitor for the treatment of colorectal cancer. MATERIALS AND METHODS: In this study, cell culture, cell death assay, 3- (4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, colony formation assay, immunoblot analysis and tumor xenograft were applied. RESULTS: CJ14939 induced cell death, and inhibited phosphorylation of JAK1 and STAT3 in colorectal cancer cells. Furthermore, CJ14939 also promoted oxaliplatin-induced cell death, up-regulated expression of cleaved caspase-3, and down-regulated expression of phospho-JAK1 and phospho-STAT3. In vivo, co-treatment with CJ14939 and oxaliplatin notably reduced tumor growth when compared with CJ14939 or oxaliplatin treatment alone. CONCLUSION: This study identifies the important potential of CJ14939 in colorectal cancer treatment and suggests that combining CJ14939 with oxaliplatin might be a novel therapeutic strategy for patients with colorectal cancer.
Assuntos
Neoplasias Colorretais , Inibidores de Janus Quinases , Animais , Morte Celular , Neoplasias Colorretais/tratamento farmacológico , Humanos , Inibidores de Janus Quinases/farmacologia , Janus Quinases/metabolismo , Oxaliplatina/farmacologia , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/fisiologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND/AIM: Rictor is an adaptor protein essential for mTORC2, which regulates cell growth and survival. The aim of this study was to identify microRNAs (miR) that down-regulate Rictor and investigate their function on breast cancer cell survival. MATERIALS AND METHODS: Trypan blue assay, MTT assay, polymerase chain reaction analysis, luciferase reporter assay and western blot analysis were carried out in breast cancer cell lines HCC1954, MDA-MB-231, SK-BR-3, and BT474. RESULTS: miR-3188 overexpression suppressed the expression of Rictor and inhibited cell viability in HCC1954 and MDA-MB-231, highly Rictor-expressing breast cancer cells. In addition, miR-3188 overexpression decreased the protein level of p-AKT at Ser473, a substrate of mTORC2. Moreover, miRNA-3188 overexpression sensitized breast cancer cells to ionizing radiation (IR) by down-regulating Rictor and p-AKT. CONCLUSION: miR-3188 enhances IR sensitivity by affecting the mTORC2/AKT signalling pathway by altering the expression of Rictor, which could be a promising therapeutic strategy for the future treatment of breast cancer.
Assuntos
Neoplasias da Mama/genética , MicroRNAs/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Neoplasias da Mama/mortalidade , Regulação para Baixo , Feminino , Humanos , Radiação Ionizante , Análise de Sobrevida , TransfecçãoRESUMO
BACKGROUND/AIM: Non-small cell lung cancer patients with epidermal growth factor receptor (EGFR) mutation have been shown to have a good response to erlotinib, a receptor tyrosine kinase inhibitor of EGFR. In this study, we found that the cell death pathways activated by erlotinib in 2D and 3D culture systems are different. MATERIALS AND METHODS: The cell death pathways induced by erlotinib were evaluated by flow cytometry and immunoblotting in both 2D and 3D culture systems of EGFR mutant lung cancer cells. RESULTS: Treatment with erlotinib induced caspase 8 activation and up-regulation of TNF-related apoptosis-inducing ligand (TRAIL) expression only in 3D cultures. Knockdown of TRAIL attenuated both erlotinib-induced activation of caspase-8 and apoptosis in 3D cultures. Erlotinib also increased LC3, an autophagy marker, expression and c-Jun N terminal kinase (JNK) activation. Both 3-MA as an autophagy inhibitor and SP600125 as a JNK inhibitor, significantly inhibited erlotinib-induced cell death. CONCLUSION: Erlotinib induces apoptotic cell death in 3D cultures through an autophagy-TRAIL-JNK pathway.
Assuntos
Técnicas de Cultura de Células/métodos , Cloridrato de Erlotinib/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Mutação , Apoptose/efeitos dos fármacos , Autofagia/fisiologia , Caspase 8/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Cloridrato de Erlotinib/uso terapêutico , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Neoplasias Pulmonares/patologia , Ligante Indutor de Apoptose Relacionado a TNF/fisiologiaRESUMO
ABT-263 (navitoclax), a Bcl-2 family protein inhibitor, was clinically tested as an anti-cancer agent. However, the clinical trials were limited given the occurrence of resistance to monotherapy in breast cancer cells. Our study investigates the mechanisms for overcoming navitoclax resistance by combining it with an mTOR inhibitor to indirectly target survivin. The apoptotic effects of navitoclax occurred in MDA-MB-231 breast cancer cells in a time- and dose-dependent fashion, but MCF-7 cells were resistant to navitoclax treatment. The expression of Bcl-2 family genes was not altered by navitoclax, but the expression of survivin, a member of the inhibitors of apoptosis proteins (IAP) family, was downregulated, which increased death signaling in MDA-MB-231 cells. In MCF-7 cells, a navitoclax-resistant cell line, combined treatment with navitoclax and everolimus synergistically reduced survivin expression and induced cell death. These data indicate that navitoclax induces cell death in MDA-MB-231 cells but not in MCF-7 cells. Decreased survivin expression in MDA-MB-231 cells may be a primary pathway for death signaling. Combined navitoclax and everolimus treatment induces cell death by reducing the stability of survivin in MCF-7 cells. Given that survivin-targeted therapy overcomes resistance to navitoclax, this strategy could be used to treat breast cancer patients.
Assuntos
Compostos de Anilina/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas Inibidoras de Apoptose/metabolismo , Sulfonamidas/farmacologia , Compostos de Anilina/administração & dosagem , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Quimioterapia Combinada , Everolimo/administração & dosagem , Everolimo/farmacologia , Feminino , Humanos , Proteínas Inibidoras de Apoptose/genética , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/administração & dosagem , Survivina , Serina-Treonina Quinases TOR/antagonistas & inibidoresRESUMO
Sulindac has anti-neoplastic properties against colorectal cancers; however, its use as a chemopreventive agent has been limited due to toxicity and efficacy concerns. Combinatorial treatment of colorectal cancers has been attempted to maximize anti-cancer efficacy with minimal side effects by administrating NSAIDs in combination with other inhibitory compounds or drugs such as l-ascorbic acid (vitamin C), which is known to exhibit cytotoxicity towards various cancer cells at high concentrations. In this study, we evaluated a combinatorial strategy utilizing sulindac and vitamin C. The death of HCT116 cells upon combination therapy occurred via a p53-mediated mechanism. The combination therapeutic resistance developed in isogenic p53 null HCT116 cells and siRNA-mediated p53 knockdown HCT116 cells, but the exogenous expression of p53 in p53 null isogenic cells resulted in the induction of cell death. In addition, we investigated an increased level of intracellular ROS (reactive oxygen species), which was preceded by p53 activation. The expression level of PUMA (p53-upregulated modulator of apoptosis), but not Bim, was significantly increased in HCT116 cells in response to the combination treatment. Taken together, our results demonstrate that combination therapy with sulindac and vitamin C could be a novel anti-cancer therapeutic strategy for p53 wild type colon cancers.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácido Ascórbico/metabolismo , Neoplasias do Colo/tratamento farmacológico , Espécies Reativas de Oxigênio/agonistas , Sulindaco/farmacologia , Proteína Supressora de Tumor p53/agonistas , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/metabolismo , Proteínas Reguladoras de Apoptose/agonistas , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Carcinoma/dietoterapia , Carcinoma/tratamento farmacológico , Carcinoma/metabolismo , Neoplasias do Colo/dietoterapia , Neoplasias do Colo/metabolismo , Terapia Combinada , Suplementos Nutricionais , Resistencia a Medicamentos Antineoplásicos , Interações Alimento-Droga , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Concentração Osmolar , Oxidantes/metabolismo , Proteínas Proto-Oncogênicas/agonistas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Colon cancer patients with mutant KRAS are resistant to cetuximab, an antibody directed against the epidermal growth factor receptor, which is an effective clinical therapy for patients with wild-type KRAS. Numerous combinatorial therapies have been tested to overcome the resistance to cetuximab. However, no combinations have been found that can be used as effective therapeutic strategies. In this study, we demonstrate that L-ascorbic acid partners with cetuximab to induce killing effects, which are influenced by sodium-dependent vitamin C transporter 2 (SVCT-2) in human colon cancer cells with a mutant KRAS. L-Ascorbic acid treatment of human colon cancer cells that express a mutant KRAS differentially and synergistically induced cell death with cetuximab in a SVCT-2-dependent manner. The ectopic expression of SVCT-2 induced sensitivity to L-ascorbic acid treatment in human colon cancer cells that do not express SVCT-2, whereas the knockdown of endogenous SVCT-2 induced resistance to L-ascorbic acid treatment in SVCT-2-positive cells. Moreover, tumor regression via the administration of L-ascorbic acid and cetuximab in mice bearing tumor cell xenografts corresponded to SVCT-2 protein levels. Interestingly, cell death induced by the combination of L-ascorbic acid and cetuximab resulted in both apoptotic and necrotic cell death. These cell death mechanisms were related to a disruption of the ERK pathway and were represented by the impaired activation of RAFs and the activation of the ASK-1-p38 pathway. Taken together, these results suggest that resistance to cetuximab in human colon cancer patients with a mutant KRAS can be bypassed by L-ascorbic acid in an SVCT-2-dependent manner. Furthermore, SVCT-2 in mutant KRAS colon cancer may act as a potent marker for potentiating L-ascorbic acid co-treatment with cetuximab.
Assuntos
Ácido Ascórbico/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Proteínas Proto-Oncogênicas p21(ras)/genética , Transportadores de Sódio Acoplados à Vitamina C/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cetuximab/administração & dosagem , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inibidores , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Triple-negative breast cancer (TNBC) is a breast cancer subtype that has an aggressive phenotype, is highly metastatic, has limited treatment options and is associated with a poor prognosis. In addition, metastatic TNBC has no preferred standard chemotherapy due to resistance to anthracyclines and taxanes. The present study demonstrated that a herbal extract, SH003, reduced cell viability and induced apoptosis in TNBC without cell cytotoxicity. Cell viability was examined using trypan blue exclusion and colony formation assays, which revealed a decrease in the cell viability. Additionally, apoptosis was determined using flow cytometry and a subG1 assay, which revealed an increase in the proportion of cells in the subG1 phase. The present study investigated the anticancer effect of SH003 in the Hs578T, MDAMB231 and ZR751 TNBC cell lines, and in the MCF7 and T47D nonTNBC cell lines. Western blot analysis revealed that the expression levels of polyADPribose polymerase (PARP) cleavage protein in cells treated with SH003 were increased dosedependent manner, indicating that SH003 induced apoptosis via a caspasedependent pathway. Pretreatment with the caspase inhibitor ZVAD reduced SH003induced apoptosis was examined using trypan blue exclusion. Moreover, SH003 treatment enhanced the p73 levels in MDAMB231 cells but not in MCF7 cells. Transfection of p73 small interfering RNA (siRNA) in MDAMB0231 cells revealed that the apoptotic cell death induced by SH003 was significantly impaired in comparison with scramble siRNA transfected MDAMB231 cells. This was examined using trypan blue exclusion and flow cytometry analysis (subG1). In addition, SH003 and paclitaxel exhibited synergistic anticancer effects on TNBC cells. The results indicate that SH003 exerts its anticancer effect via p73 protein induction and exhibits synergistic anticancer effects when combined with paclitaxel.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Extratos Vegetais/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Proteína Tumoral p73/metabolismo , Angelica , Astrágalo , Mama/efeitos dos fármacos , Mama/metabolismo , Mama/patologia , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Paclitaxel/farmacologia , Trichosanthes , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
BACKGROUND/AIMS: Fibroblast growth factor signaling is involved in hepatocarcinogenesis. The aim of this study was to determine the fibroblast growth factor receptor (FGFR) isotype expression in hepatocellular carcinoma (HCC) and neighboring nonneoplastic liver tissue, and elucidate its prognostic implications. METHODS: Immunohistochemical staining of FGFR1, -2, -3, and -4 was performed in the HCCs and paired neighboring nonneoplastic liver tissue of 870 HCC patients who underwent hepatic resection. Of these, clinical data for 153 patients who underwent curative resection as a primary therapy were reviewed, and the relationship between FGFR isotype expression and overall survival was evaluated (development set). This association was also validated in 73 independent samples (validation set) by Western blot analysis. RESULTS: FGFR1, -2, -3, and -4 were expressed in 5.3%, 11.1%, 3.8%, and 52.7% of HCCs, respectively. Among the development set of 153 patients, FGFR2 positivity in HCC was associated with a significantly shorter overall survival (5-year survival rate, 35.3% vs. 61.8%; P=0.02). FGFR2 expression in HCC was an independent predictor of a poor postsurgical prognosis (hazard ratio, 2.10; P=0.02) in the development set. However, the corresponding findings were not statistically significant in the validation set. CONCLUSIONS: FGFR2 expression in HCC could be a prognostic indicator of postsurgical survival.