RESUMO
PURPOSE: Okadaic acid class of tumor promoters are transformed into endogenous protein inhibitors of PP2A, SET, and CIP2A in human cancers. This indicates that inhibition of PP2A activity is a common mechanism of cancer progression in humans. It is important to study the roles of SET and CIP2A vis-à-vis their clinical significance on the basis of new information gathered from a search of PubMed. RESULTS AND DISCUSSION: The first part of this review introduces the carcinogenic roles of TNF-α and IL-1, which are induced by the okadaic acid class of compounds. The second part describes unique features of SET and CIP2A in cancer progression for several types of human cancer: (1) SET-expressing circulating tumor cells (SET-CTCs) in breast cancer, (2) knockdown of CIP2A and increased PP2A activity in chronic myeloid leukemia, (3) CIP2A and epidermal growth factor receptor (EGFR) activity in erlotinib sensitive- and resistant-non-small cell lung cancer, (4) SET antagonist EMQA plus radiation therapy against hepatocellular carcinoma, (5) PP2A inactivation as a common event in colorectal cancer, (6) prostate cancer susceptibility variants, homeobox transcription factor (HOXB13 T) and CIP2A T, and (7) SET inhibitor OP449 for pre-clinical investigation of pancreatic cancer. In the Discussion, the binding complex of SET is briefly introduced, and overexpression of SET and CIP2A proteins is discussed in relation to age-associated chronic inflammation (inflammaging). CONCLUSION: This review establishes the concept that inhibition of PP2A activity is a common mechanism of human cancer progression and activation of PP2A activity leads to effective anticancer therapy.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Hepáticas , Neoplasias Pulmonares , Masculino , Humanos , Ácido Okadáico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinógenos , Neoplasias Pulmonares/tratamento farmacológico , Proteínas de Membrana/metabolismo , Linhagem Celular Tumoral , Peptídeos e Proteínas de Sinalização Intracelular/genética , Autoantígenos/metabolismoRESUMO
Bio-orthogonal ligations that crosslink living cells with a substrate or other cells require high stability and rapid kinetics to maintain the nature of target cells. In this study, we report water-soluble cyclooctadiyne (WS-CODY) derivatives that undergo an ion-pair enhanced double-click reaction. The cationic side chain of WS-CODY accelerated the kinetics on the azide-modified cell surface due to proximity effect. Cationic WS-CODY was able to crosslink azide-modified, poorly adherent human lung cancer PC-9 cells not only to azide-grafted glass substrates but also to other cells within 5-30 min. We discovered that cell-substrate crosslinking induced the ITGA5 gene expression, whereas cell-cell crosslinking induced the CTNNA1 gene, according to the adhesion partner. Ion-pair-enhanced WS-CODY can be applied to a wide range of cells with established azide modifications and is expected to provide a powerful tool to regulate cell-substrate and cell-cell interactions.
RESUMO
To understand the mechanism underlying metastasis, identification of a mechanism-based and common biomarker for circulating tumour cells (CTCs) in heterogenous breast cancer is needed. SET, an endogenous inhibitor of protein phosphatase 2A, was overexpressed in all subtypes of invasive breast carcinoma tissues. Treatment with SET-targeted siRNAs reduced the motility of MCF-7 and MDA-MB-231 cells in transwell assay. SET knockdown reduced the number of mammospheres by 60-70% in MCF-7 and MDA-MB-231 cells, which was associated with the downregulation of OCT4 and SLUG. Hence, we analysed the presence of SET-expressing CTCs (SET-CTCs) in 24 breast cancer patients. CTCs were enriched using a size-based method and then immunocytochemically analysed using an anti-SET antibody. SET-CTCs were detected in 6/6 (100%) patients with recurrent breast cancer with a median value of 12 (12 cells/3 mL blood), and in 13/18 (72.2%) patients with stage I-III breast cancer with a median value of 2.5, while the median value of healthy controls was 0. Importantly, high numbers of SET-CTCs were correlated with lymph node metastasis in patients with stage I-III disease. Our results indicate that SET contributes to breast cancer progression and can act as a potential biomarker of CTCs for the detection of metastasis.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Inibidores Enzimáticos/metabolismo , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Proteína Fosfatase 2/antagonistas & inibidores , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Metástase Linfática , Células MCF-7 , Proteína Fosfatase 2/metabolismoRESUMO
The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.
Assuntos
Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Neoplasias Gástricas/microbiologia , Animais , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Transição Epitelial-Mesenquimal , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/terapia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Proteínas Imediatamente Precoces/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Fatores de Risco , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/prevenção & controle , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Supressoras de Tumor/metabolismo , NucleolinaRESUMO
Over the past 30 years, research of green tea polyphenols, especially (-)-epigallocatechin gallate (EGCG), has revealed that consumption of green tea is a practical and effective primary cancer prevention method for the general population. More recently, we believe that green tea polyphenols are beneficial for tertiary cancer prevention using green tea alone or combined with anticancer drugs because EGCG has the potential to inhibit metastatic progression and stemness, and enhance antitumor immunity. In an effort to identify a common underlying mechanism responsible for EGCG's multifunctional effects on various molecular targets, we studied the biophysical effects of EGCG on cell stiffness using atomic force microscopy. We found that EGCG acts to stiffen the membranes of cancer cells, leading to inhibition of signaling pathways of various receptors. Stiffening of membranes with EGCG inhibited AXL receptor tyrosine kinase, a stimulator of cell softening, motility and stemness, and expression of programmed cell death-ligand 1. This review covers the following: i) primary cancer prevention using EGCG or green tea, ii) tertiary cancer prevention by combining EGCG and anticancer drugs, iii) inhibition of metastasis with EGCG by stiffening the cell membrane, iv) inhibition of AXL receptor tyrosine kinase, a stimulator of cell softening and motility, with EGCG, v) inhibition of stemness properties with EGCG, and vi) EGCG as an alternative chemical immune checkpoint inhibitor. Development of new drugs that enhance stiffening of cancer cell membranes may be an effective strategy for tertiary cancer prevention and treatment.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Membrana Celular/efeitos dos fármacos , Neoplasias/prevenção & controle , Polifenóis/farmacologia , Chá/química , Antineoplásicos Fitogênicos/química , Membrana Celular/metabolismo , Humanos , Estrutura Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Polifenóis/químicaRESUMO
Cancer stem cells (H1299-sdCSCs) were obtained from tumour spheres of H1299 human lung cancer cells. We studied low stiffness, a unique biophysical property of cancer cells, in H1299-sdCSCs and parental H1299. Atomic force microscopy revealed an average Young's modulus value of 1.52 kPa for H1299-sdCSCs, which showed low stiffness compared with that of H1299 cells, with a Young's modulus value of 2.24 kPa. (-)-Epigallocatechin gallate (EGCG) reversed the average Young's modulus value of H1299-sdCSCs to that of H1299 cells. EGCG treatment inhibited tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. AXL receptor tyrosine kinase is highly expressed in H1299-sdCSCs and AXL knockdown with siAXLs significantly reduced tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. An AXL-high population of H1299-sdCSCs was similarly reduced by treatment with EGCG and siAXLs. Transplantation of an AXL-high clone isolated from H1299 cells into SCID/Beige mice induced faster development of bigger tumour than bulk H1299 cells, whereas transplantation of the AXL-low clone yielded no tumours. Oral administration of EGCG and green tea extract (GTE) inhibited tumour growth in mice and reduced p-AXL, ALDH1A1, and SLUG in tumours. Thus, EGCG inhibits the stemness and tumourigenicity of human lung cancer cells by inhibiting AXL.
Assuntos
Anticarcinógenos/farmacologia , Carcinogênese/efeitos dos fármacos , Catequina/análogos & derivados , Neoplasias Pulmonares/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Anticarcinógenos/uso terapêutico , Carcinogênese/metabolismo , Carcinogênese/patologia , Catequina/farmacologia , Catequina/uso terapêutico , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos SCID , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptor Tirosina Quinase AxlRESUMO
PURPOSE: The 14th Japan-Korea joint symposium on cancer and aging research was held at an auditorium of Saga University, Japan, May 31-Jun 2, 2018. Participants presented 31 oral and 21 poster presentations, two lectures at a luncheon seminar, plus special lectures from two Korean Emeritus Professors and founders of our joint symposia. The essential parts of the lectures are reviewed here. RESULTS: This Symposium was called Japan-Korea, because the host country comes first. Our symposia are organized every 18 months and the program includes keynote and plenary lectures, and oral and poster presentations. (1) Subjects related to cancer development at this symposium were: prostate cancer progression, molecules activating GSK3ß, suppressing the activation of cancer stem cells, profiling human B cell receptor repertoires, and hereditary gastrointestinal cancer syndrome. (2) Subjects related to treatment were: G-quadruplex ligands for glioma stem cells, tankyrase inhibitor for colorectal cancer, and eradication of ATL. (3) Cancer prevention subjects were: physical adsorption of EGCG to cell membrane, inhibition of immune evasion of cancer cells with EGCG, and prevention with antidiabetic agents. (4) Aging subjects were life span extension with Toll-like receptor 5 vaccine and reversal of senescence with inhibitors of ATM and ROCK. (5) The results of epidemiology focused on aldehyde dehyrogenase-2 and alcohol consumption. CONCLUSION: The 14th symposium demonstrated the cutting-edge of presentations with discussion of numerous ideas by the participants.
Assuntos
Envelhecimento , Neoplasias , Medicina de Precisão , Pesquisa Translacional Biomédica , Humanos , Japão , República da CoreiaRESUMO
PURPOSE: The okadaic acid class of tumor promoters, which are inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A), induced tumor promotion in mouse skin, rat glandular stomach, and rat liver. Endogenous protein inhibitors of PP2A, SET and CIP2A, were up-regulated in various human cancers, so it is vital to review the essential mechanisms of tumor promotion by the okadaic acid class compounds, together with cancer progression by SET and CIP2A in humans. RESULTS AND DISCUSSION: The first part of this review introduces the okadaic acid class compounds and the mechanism of tumor promotion: (1) inhibition of PP1 and PP2A activities of the okadaic acid class compounds; (2) some topics of tumor promotion; (3) TNF-α gene expression as a central mediator in tumor promotion; (4) exposure to the okadaic acid class of tumor promoters in relation to human cancer. The second part emphasizes the overexpression of SET and CIP2A in cancer progression, and the anticancer activity of SET antagonists as follows: (5) isolation and characterization of SET; (6) isolation and characterization of CIP2A; (7) progression of leukemia with SET; (8) progression of breast cancer with SET and CIP2A; (9) progression of lung cancer with SET; (10) anti-carcinogenic effects of SET antagonists OP449 and FTY720; and also (11) TNF-α-inducing protein of Helicobacter pylori, which is a clinical example of the okadaic acid pathway. CONCLUSIONS: The overexpression of endogenous protein inhibitors of PP2A, SET and CIP2A, is tightly linked to the progression of various human cancers, as well as Alzheimer's disease.
Assuntos
Autoantígenos/metabolismo , Chaperonas de Histonas/metabolismo , Proteínas de Membrana/metabolismo , Neoplasias/etiologia , Neoplasias/metabolismo , Ácido Okadáico/efeitos adversos , Proteína Fosfatase 2/metabolismo , Fatores de Transcrição/metabolismo , Animais , Autoantígenos/genética , Biomarcadores Tumorais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Proteínas de Ligação a DNA , Progressão da Doença , Exposição Ambiental/efeitos adversos , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/química , Regulação Neoplásica da Expressão Gênica , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/metabolismo , Chaperonas de Histonas/antagonistas & inibidores , Chaperonas de Histonas/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Ácido Okadáico/química , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/genética , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The anticancer activity of immune checkpoint inhibitors is attracting attention in various clinical sites. Since green tea catechin has cancer-preventive activity in humans, whether green tea catechin supports the role of immune checkpoint inhibitors was studied. We here report that (-)-epigallocatechin gallate (EGCG) inhibited programmed cell death ligand 1 (PD-L1) expression in nonâ»small-cell lung cancer cells, induced by both interferon (IFN)-γ and epidermal growth factor (EGF). The mRNA and protein levels of IFN-γâ»induced PD-L1 were reduced 40â»80% after pretreatment with EGCG and green tea extract (GTE) in A549 cells, via inhibition of JAK2/STAT1 signaling. Similarly, EGF-induced PD-L1 expression was reduced about 37â»50% in EGCG-pretreated Lu99 cells through inhibition of EGF receptor/Akt signaling. Furthermore, 0.3% GTE in drinking water reduced the average number of tumors per mouse from 4.1 ± 0.5 to 2.6 ± 0.4 and the percentage of PD-L1 positive cells from 9.6% to 2.9%, a decrease of 70%, in lung tumors of A/J mice given a single intraperitoneal injection of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In co-culture experiments using F10-OVA melanoma cells and tumor-specific CD3+ T cells, EGCG reduced PD-L1 mRNA expression about 30% in F10-OVA cells and restored interleukin-2 mRNA expression in tumor-specific CD3+ T cells. The results show that green tea catechin is an immune checkpoint inhibitor.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Catequina/farmacologia , Imunomodulação/efeitos dos fármacos , Chá/química , Animais , Antineoplásicos Fitogênicos/química , Catequina/química , Linhagem Celular Tumoral , Modelos Animais de Doenças , Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
To understand the regulation of Helicobacter pylori (H. pylori)-associated gastric carcinogenesis, we examined the effect of B-cell translocation gene 2 (BTG2) expression on the biological activity of Tipα, an oncoprotein secreted from H. pylori. BTG2, the human ortholog of mouse TIS21 (BTG2/TIS21), has been reported to be a primary response gene that is transiently expressed in response to various stimulations. Here, we report that BTG2 is constitutively expressed in the mucous epithelium and parietal cells of the gastric gland in the stomach. Expression was increased in the mucous epithelium following H. pylori infection in contrast to its loss in human gastric adenocarcinoma. Indeed, adenoviral transduction of BTG2/TIS21 significantly inhibited Tipα activity in MKN-1 and MGT-40, human and mouse gastric cancer cells, respectively, thereby downregulating tumor necrosis factor-α (TNFα) expression and Erk1/2 phosphorylation by reducing expression of nucleolin, a Tipα receptor. Chromatin immunoprecipitation proved that BTG2/TIS21 inhibited Sp1 expression and its binding to the promoter of the nucleolin gene. In addition, BTG2/TIS21 expression significantly reduced membrane-localized nucleolin expression in cancer cells, and the loss of BTG2/TIS21 expression induced cytoplasmic nucleolin availability in gastric cancer tissues, as evidenced by immunoblotting and immunohistochemistry. Higher expression of BTG2 and lower expression of nucleolin were accompanied with better overall survival of poorly differentiated gastric cancer patients. This is the first report showing that BTG2/TIS21 inhibits nucleolin expression via Sp1 binding, which might be associated with the inhibition of H. pylori-induced carcinogenesis. We suggest that BTG2/TIS21 is a potential inhibitor of nucleolin in the cytoplasm, leading to inhibition of carcinogenesis after H. pylori infection.
Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Imediatamente Precoces/metabolismo , Fosfoproteínas/genética , Proteínas de Ligação a RNA/genética , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Biomarcadores Tumorais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Proteínas Imediatamente Precoces/genética , Estimativa de Kaplan-Meier , Camundongos , Modelos Biológicos , Fosfoproteínas/metabolismo , Prognóstico , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas de Ligação a RNA/metabolismo , Fator de Transcrição Sp1/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Proteínas Supressoras de Tumor/genética , NucleolinaRESUMO
Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes ground-breaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.
Assuntos
Catequina/análogos & derivados , Neoplasias/prevenção & controle , Células-Tronco Neoplásicas/efeitos dos fármacos , Chá/química , Animais , Catequina/uso terapêutico , Movimento Celular/efeitos dos fármacos , Ensaios Clínicos como Assunto , Humanos , Camundongos , Neoplasias/patologia , Fitoterapia/métodos , Fitoterapia/tendênciasRESUMO
To study the role of cell softening in malignant progression, Transwell assay and atomic force microscope were used to classify six human non-small cell lung cancer cell lines into two groups: a high motility-low stiffness (HMLS) group and a low motility-high stiffness (LMHS) group. We found a significant role of activity of the AXL receptor tyrosine kinase, which belongs to the TAM (Tyro3, AXL, Mer) family, in the stimulation of motility and cell softening. HMLS cells expressed higher AXL levels than LMHS cells and contained phosphorylated AXL. H1703 LMHS cells transfected with exogenous AXL exhibited increased motility and decreased stiffness, with low levels of actin stress fibre formation. Conversely, the AXL-specific inhibitor R428 and AXL-targeting siRNA reduced motility and increased stiffness in H1299 HMLS cells. Knockdown of AXL stimulated actin stress fibre formation, which inhibited tumour formation in a mouse xenograft model. The Ras/Rac inhibitor SCH 51344, which blocks disruption of actin stress fibres, exerted similar effects to AXL inactivation. We therefore propose that the Ras/Rac pathway operates downstream of AXL. Thus, AXL activation-induced cell softening promotes malignant progression in non-small cell lung cancer and represents a key biophysical property of cancer cells.
Assuntos
Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Células A549 , Animais , Apoptose/fisiologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Progressão da Doença , Feminino , Humanos , Camundongos , Camundongos SCID , Fosforilação/fisiologia , RNA Interferente Pequeno/metabolismo , c-Mer Tirosina Quinase/metabolismo , Receptor Tirosina Quinase AxlRESUMO
PURPOSE: Our previous experiments show that the main constituent of green-tea catechins, (-)-epigallocatechin gallate (EGCG), completely prevents tumor promotion on mouse skin initiated with 7,12-dimethylbenz(a)anthracene followed by okadaic acid and that EGCG and green tea extract prevent cancer development in a wide range of target organs in rodents. Therefore, we focused our attention on human cancer stem cells (CSCs) as targets of cancer prevention and treatment with EGCG. METHODS: The numerous reports concerning anticancer activity of EGCG against human CSCs enriched from cancer cell lines were gathered from a search of PubMed, and we hope our review of the literatures will provide a broad selection for the effects of EGCG on various human CSCs. RESULTS: Based on our theoretical study, we discuss the findings as follows: (1) Compared with the parental cells, human CSCs express increased levels of the stemness markers Nanog, Oct4, Sox2, CD44, CD133, as well as the EMT markers, Twist, Snail, vimentin, and also aldehyde dehydrogenase. They showed decreased levels of E-cadherin and cyclin D1. (2) EGCG inhibits the transcription and translation of genes encoding stemness markers, indicating that EGCG generally inhibits the self-renewal of CSCs. (3) EGCG inhibits the expression of the epithelial-mesenchymal transition phenotypes of human CSCs. (4) The inhibition of EGCG of the stemness of CSCs was weaker compared with parental cells. (5) The weak inhibitory activity of EGCG increased synergistically in combination with anticancer drugs. CONCLUSIONS: Green tea prevents human cancer, and the combination of EGCG and anticancer drugs confers cancer treatment with tissue-agnostic efficacy.
Assuntos
Neoplasias/prevenção & controle , Células-Tronco Neoplásicas/efeitos dos fármacos , Animais , Biomarcadores Tumorais/metabolismo , Catequina/análogos & derivados , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologiaRESUMO
A single-round DNA aptamer selection for mammalian cells was successfully achieved for the first time using a capillary electrophoresis (CE)-based methodology called polymer-enhanced capillary transient isotachophoresis (PectI). The PectI separation yielded a single peak for the human lung cancer cell line (PC-9) complexed with DNA aptamer candidates, which was effectively separated from a free randomized DNA library peak, ensuring no contamination from free DNA in the PC-9-DNA aptamer complex fraction. The DNA aptamer candidates obtained after a single-round selection employing counter selection with HL-60 were proven to bind selectively and form kinetically stable complexes with PC-9 cells. Interestingly, most aptamer candidates showed high binding ability (Kd = 70-350 nM) with different extents of binding on the cell surface. These facts proved that a single-round selection for mammalian cells by PectI is feasible to obtain various types of aptamer candidates, which have high-affinity even for non-overexpressed but unique targets on the cell surface in addition to overexpressed targets.
Assuntos
Aptâmeros de Nucleotídeos , Eletroforese Capilar , Biblioteca Gênica , Isotacoforese , Linhagem Celular Tumoral , Humanos , PolímerosRESUMO
Physical interactions of four major green tea catechin derivatives with cell membrane models were systemically investigated. Catechins with the galloyl moiety caused the aggregation of small unilamellar vesicles and an increase in the surface pressure of lipid monolayers, while those without did not. Differential scanning calorimetry revealed that, in a low concentration regime (≤10 µM), catechin molecules are not significantly incorporated into the hydrophobic core of lipid membranes as substitutional impurities. Partition coefficient measurements revealed that the galloyl moiety of catechin and the cationic quaternary amine of lipids dominate the catechin-membrane interaction, which can be attributed to the combination of electrostatic and cation-π interactions. Finally, we shed light on the mechanical consequence of catechin-membrane interactions using the Fourier-transformation of the membrane fluctuation. Surprisingly, the incubation of cell-sized vesicles with 1 µM galloyl catechins, which is comparable to the level in human blood plasma after green tea consumption, significantly increased the bending stiffness of the membranes by a factor of more than 60, while those without the galloyl moiety had no detectable influence. Atomic force microscopy and circular dichroism spectroscopy suggest that the membrane stiffening is mainly attributed to the adsorption of galloyl catechin aggregates to the membrane surfaces. These results contribute to our understanding of the physical and thus the generic functions of green tea catechins in therapeutics, such as cancer prevention.
Assuntos
Catequina/análogos & derivados , Bicamadas Lipídicas/química , Adsorção , Varredura Diferencial de Calorimetria , Catequina/química , Catequina/metabolismo , Dicroísmo Circular , Difusão Dinâmica da Luz , Humanos , Interações Hidrofóbicas e Hidrofílicas , Bicamadas Lipídicas/metabolismo , Microscopia de Força AtômicaRESUMO
PURPOSE: In 1988, we first reported the complete chemical structure of a new type of phorbol ester, abbreviated to DHPB, found in seed oil of Jatropha curcas L. (Saboodam in Thai) and its tumor-promoting activity on mouse skin. Although this seed oil contains toxic phorbol ester, it was planned to use it as a feasible renewable oil and the extracted seed cake as fertilizer. This utilization value opened a new science of Jatropha curcas. METHODS: The main experimental results are cited from our publications, and the relevant literature screened from journals and PubMed. RESULTS AND DISCUSSION: This paper begins with our original work on the structural elucidation of a new phorbol ester, 12-deoxy-16-hydroxyphorbol (DHPB): its tumor-promoting activity was compared with that of TPA. We think that it is timely to review the following research advances with Jatropha curcas, so numerous topics are classified as follows: (1) historical development of phorbol esters in seed oil; (2) toxicity of phorbol ester based on various bioassays; (3) degradation of phorbol ester; (4) a new pharmaceutical compound in seed; and (5) tumor promotion and progression with endogeneous tumor promoters in human carcinogenesis. The discovery of phorbol ester in seed oil raised awareness of the danger of public use of seed oil and seed cake in Thailand, and also indicated the necessity of discussing the concept of primary and tertiary cancer preventions. CONCLUSION: It is worthwhile to study the future benefits and cancer risks of globally distributed Jatropha curcas L.
Assuntos
Carcinogênese/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Ésteres de Forbol/uso terapêutico , Óleos de Plantas/uso terapêutico , Humanos , Jatropha/química , Neoplasias/patologia , Ésteres de Forbol/química , Óleos de Plantas/química , Sementes/químicaRESUMO
(-)-Epigallocatechin gallate (EGCG), a green tea catechin, acts as a synergist with various anticancer drugs, including retinoids. Am80 is a synthetic retinoid with a different structure from all-trans-retinoic acid: Am80 is now clinically utilized as a new drug for relapsed and intractable acute promyelocytic leukemia patients. Our experiments showed that the combination of EGCG and Am80 synergistically induced both apoptosis in human lung cancer cell line PC-9 and up-regulated expressions of growth arrest and DNA damage-inducible gene 153 (GADD153), death receptor 5, and p21waf1 genes in the cells. To understand the mechanisms of synergistic anticancer activity of the combination, we gave special attention to the lysine acetylation of proteins. Proteomic analysis using nanoLC-ESI-MS/MS revealed that PC-9 cells treated with the combination contained 331 acetylated proteins, while nontreated cells contained 553 acetylated proteins, and 59 acetylated proteins were found in both groups. Among them, the combination increased acetylated-p53 and acetylated-α-tubulin through reduction of histone deacetylase (HDAC) activity in cytosol fraction, although the levels of acetylation in histones H3 or H4 did not change, and the combination reduced protein levels of HDAC4, -5 and -6 by 20% to 80%. Moreover, we found that a specific inhibitor of HDAC4 and -5 strongly induced p21waf1 gene expression, and that of HDAC6 induced both GADD153 and p21waf1 gene expression, which resulted in apoptosis. All results demonstrate that EGCG in combination with Am80 changes levels of acetylation in nonhistone proteins via down-regulation of HDAC4, -5 and -6 and stimulates apoptotic induction.
Assuntos
Benzoatos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Catequina/análogos & derivados , Inibidores de Histona Desacetilases/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Tetra-Hidronaftalenos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Catequina/farmacologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Desacetilase 6 de Histona/antagonistas & inibidores , Desacetilase 6 de Histona/metabolismo , Histona Desacetilases/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Chá/química , Fator de Transcrição CHOP/genéticaRESUMO
Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (-)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young's moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young's moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.
Assuntos
Fenômenos Bioquímicos , Catequina/farmacologia , Neoplasias/prevenção & controle , Chá/química , Animais , Catequina/análogos & derivados , Catequina/química , Catequina/uso terapêutico , Movimento Celular/efeitos dos fármacos , Humanos , Microfluídica , Microscopia de Força Atômica , Fenômenos Ópticos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêuticoRESUMO
The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) α and PKCß1 exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. PKCα accompanied pErk1/2 to the nucleus after freeing it from PEA-15pS(104) via PKCß1 and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of PKCα were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated PKCα expression and increased epidermal and hair follicle cell proliferation. Thus, PKCα downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear PKCα degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of PKCα expression following TPA treatment reduces pErk1/2-activated SP1 biding to the p21(WAF1) gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.
Assuntos
Senescência Celular/efeitos dos fármacos , Fibroblastos/citologia , Proteína Quinase C beta/metabolismo , Proteína Quinase C-alfa/metabolismo , Acetato de Tetradecanoilforbol/análogos & derivados , Animais , Proliferação de Células/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Adhesion of cancer cells with different metastatic potential and anticancer drug resistance has been quantitatively evaluated by using self-assembled monolayer (SAM)-patterned substrates and reflection interference contrast microscopy (RICM). Cell-adhesive SAM spots with optimized diameter could prevent cell-cell adhesion and thus allowed the systematic evaluation of statistically reliable numbers of contact area between single cancer cells and substrates by RICM. The statistical image analysis revealed that highly metastatic mouse melanoma cells showed larger contact area than lowly metastatic cells. We also found that both cancer cell types exhibited distinct transition from the "strong" to "weak" adhesion states with increase in the concentration of (-)-epigallocatechin gallate (EGCG), which is known to exhibit cancer preventive activity. Mathematical analysis of the adhesion transition revealed that adhesion of the highly metastatic mouse melanoma cells showed more EGCG tolerance than that of lowly metastatic cells. Moreover, time-lapse RICM observation revealed that EGCG weakened cancer cell adhesion in a stepwise manner, probably via focal adhesion complex. These results clearly indicate that contact area can be used as a quantitative measure for the determination of cancer phenotypes and their drug resistance, which will provide physical insights into the mechanism of cancer metastasis and cancer prevention.