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1.
Br J Cancer ; 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32203206

RESUMO

BACKGROUND: Recent studies have shown that multidrug resistance may be induced by the high stemness of cancer cells. Following prolonged chemotherapy, MDR protein 1 (MDR1) and CD133 increase in CRC, but the relationship between them is unclear. METHODS: The relationship between MDR and CSC properties in CRC was determined via CCK-8 assay, apoptosis assay, DOX uptake and retention, immunohistochemistry, immunofluorescence and flow cytometry. The correlations between their expression levels were evaluated using Spearman's rank statistical test and the Mann-Whitney test. Furthermore, the effect of CD133 on the repression of the AKT/NF-κB/MDR1 signalling pathway was investigated in vitro and in vivo. RESULTS: We found that CD133 increased with the emergence of drug-resistance phenotypes, and the high expression of MDR1/P-gp was consistently accompanied by positive expression of CD133 as demonstrated by the analysis of patient samples. Up- or downregulation of CD133 could regulate MDR via AKT/NF-κB/MDR1 signalling in CRC. A rescue experiment showed that the AKT/NF-κB signalling pathway is the main mechanism by which CD133 regulates MDR1/P-gp expression in CRC. CONCLUSIONS: Taken together, our results suggest that targeting CD133 reverses drug resistance via the AKT/NF-κB/MDR1 pathway and that this pathway might serve as a potential therapeutic target to reverse MDR in CRC.

2.
Cancer Sci ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32058643

RESUMO

Recent studies have shown that MDR could be induced by the high stemness of cancer cells. In a previous study, we found bufalin could reverse MDR and inhibit cancer cell stemness in colorectal cancer, but the relationship between them was unclear. Here we identified overexpressing CD133 increases levels of Akt/nuclear factor-κB signaling mediators and MDR1, while increasing cell chemoresistance. Furthermore, bufalin reverses colorectal cancer MDR by regulating cancer cell stemness through the CD133/nuclear factor-κB/MDR1 pathway in vitro and in vivo. Taken together, our results suggest that bufalin could be developed as a novel 2-pronged drug that targets CD133 and MDR1 to eradicate MDR cells and could ultimately be combined with conventional chemotherapeutic agents to improve treatment outcomes for patients with colorectal cancer.

3.
Mol Ther ; 27(10): 1810-1824, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31208913

RESUMO

Hypoxia is associated with poor prognosis and therapeutic resistance in cancer patients. Accumulating evidence has shown that microRNA (miRNA) plays an important role in the acquired drug resistance in colorectal carcinoma (CRC). However, the role of miRNA in hypoxia-induced CRC drug resistance remains to be elucidated. Here, we identified a hypoxia-triggered feedback loop that involves hypoxia-inducible transcription factor 1α (HIF-1α)-mediated repression of miR-338-5p and confers drug resistance in CRC. In this study, the unbiased miRNA array screening revealed that miR-338-5p is downregulated in both hypoxic CRC cell lines tested. Repression of miR-338-5p was required for hypoxia-induced CRC drug resistance. Furthermore, we identified interleukin-6 (IL-6), which mediates STAT3/Bcl2 activation under hypoxic conditions, as a direct miR-338-5p target. The resulting HIF-1α/miR-338-5p/IL-6 feedback loop was necessary for drug resistance in colon cancer cell lines. Using CRC patient samples, we found miR-338-5p has a negative correlation with HIF-1α and IL-6. Finally, in a xenograft model, overexpressing miR-338-5p in CRC cells and HIF-1α inhibitor PX-478 were able to enhance the sensitivity of CRC to oxaliplatin (OXA) via suppressing the HIF-1α/miR-338-5p/IL-6 feedback loop in vivo. Taken together, our results uncovered an HIF-1α/miR-338-5p/IL-6 feedback circuit that is critical in hypoxia-mediated drug resistance in CRC; targeting each member of this feedback loop could potentially reverse hypoxia-induced drug resistance in CRC.

4.
J Biomed Nanotechnol ; 15(2): 329-339, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30596555

RESUMO

Bufalin has significant antitumor effects on various kinds of tumors. However, bufalin's clinical utility is severely limited because of its side effects, toxicity, and fast metabolism. We made bufalin-loaded, targeted nanospheres with the aim of overcoming bufalin's limitations. Epidermal growth factor (EGF)-modified nanospheres with encapsulated bufalin showed increased toxicity in colorectal cancer cells, inhibition of cell proliferation, and induction of apoptosis relative to the non-EGF-modified nanospheres. The average particle size of the nanospheres was 171 nm and the encapsulation efficiency was 83.2%. In vitro release data showed that bufalin loaded in calcium phosphate/DPPE-PEG-EGF hybrid porous nanospheres was released more slowly from dialysis membranes than free bufalin. According to our results, EGF-modified nanospheres containing bufalin show improved anti-tumor effects on colon cancer in nude mice, but without severe side effects.


Assuntos
Nanosferas , Animais , Antineoplásicos , Bufanolídeos , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico , Camundongos , Camundongos Nus , Fosfatidiletanolaminas , Polietilenoglicóis
5.
Int J Nanomedicine ; 13: 7533-7548, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30532537

RESUMO

Background: Multidrug resistance (MDR) is the major reason for the failure of chemotherapy in colon cancer. Bufalin (BU) is one of the most effective antitumor active constituents in Chansu. Our previous study found that BU can effectively reverse P-glycoprotein (P-gp)-mediated MDR in colon cancer. However, the clinical application of BU is limited due to its low solubility in water and high toxicity. In the present study, a multifunctional delivery system based on vitamin-E- succinate grafted chitosan oligosaccharide (VES-CSO) and cyclic (arginine-glycine-aspartic acid peptide) (RGD)-modified d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was prepared by emulsion solvent evaporation method for targeted delivery of BU to improve the efficacy of drug-resistant colon cancer therapy. Methods: The cytotoxicity of BU-loaded micelles against drug-resistant colon cancer LoVo/ADR and HCT116/LOHP cells was measured by CCK-8 assay. The cellular uptake, Rho123 accumulation, and cell apoptosis were determined by flow cytometry. The expression of apoptosis-related protein and P-gp was measured by Western blot assay. The antitumor activity of BU-loaded micelles was evaluated in LoVo/ADR-bearing nude mice. Results: BU-loaded VES-CSO/TPGS-RGD mixed micelles (BU@VeC/T-RGD MM) were 140.3 nm in diameter with zeta potential of 8.66 mV. The BU@VeC/T-RGD MM exhibited good stability, sustained-release pattern, higher intracellular uptake, and greater cytotoxicity in LoVo/ADR cells. Furthermore, the mechanisms of the BU@VeC/T-RGD MM to overcome MDR might be due to enhanced apoptosis rate and P-gp efflux inhibition. Subsequently, in vivo studies confirmed an enhanced therapeutic efficiency and reduced side effects associated with BU@VeC/T-RGD MM compared with free BU, owing to the enhanced permeation and retention effect, improved pharmacokinetic behavior, and tumor targeting, which lead to MDR-inhibiting effect in LoVo/ADR-bearing nude mice. Conclusion: Our results demonstrated that VeC/T-RGD MM could be developed as a potential delivery system for BU to improve its antitumor activity against drug-resistant colon cancer.


Assuntos
Bufanolídeos/uso terapêutico , Quitosana/química , Neoplasias do Colo/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Micelas , Oligopeptídeos/química , Oligossacarídeos/química , Vitamina E/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Bufanolídeos/farmacologia , Neoplasias do Colo/patologia , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Células HCT116 , Humanos , Camundongos Nus , Rodamina 123/metabolismo , Carga Tumoral
6.
Exp Ther Med ; 15(6): 5084-5090, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29805534

RESUMO

Diabetes mellitus (DM) complications affect patients and cause varying damage. Skin ulcers exhibit difficulties in wound healing, and the regulatory basis for this remains unclear. High glucose concentration (HG) was utilized to mimic DM in cultured cells. Reverse transcription-quantitative polymerase chain reaction, western blotting and fluorescence dye analyses were performed to analyze the effects of hedgehog signaling in regulation of HG or diabetes in fibroblasts. HG-stress suppressed hedgehog-signaling gene expression, whereas the apoptosis and inflammatory response markers, Caspase-3 and plasminogen activator inhibitor-1 (PAI1), respectively, were induced. In addition, HG-stress inhibited the fibroblast proliferation rate. In parallel, treatment with Sonic hedgehog (Shh), an activator of hedgehog signaling, together with HG eliminated effects of HG on expression of hedgehog-signaling genes, Caspase-3 and PAI1, and rescued the cell proliferation rate in fibroblasts. In addition, Shh application activated c-Jun N-terminal kinase (JNK), which was inhibited by HG stress. sp600125, a JNK specific inhibitor, treatment inhibited the effect of Shh on fibroblast proliferation and hedgehog-signaling marker gene expression. Furthermore, zinc finger protein Gli1 (Gli1) overexpression partially eliminated the effect of HG and sp600125 on fibroblast proliferation, and reduced HG-induced ROS generation in fibroblasts. Together, these results indicate that HG stress inhibits hedgehog signaling, and Shh-JNK-Gli1 pathway positively regulates HG-induced damage on fibroblasts.

7.
Colloids Surf B Biointerfaces ; 166: 224-234, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29602078

RESUMO

A well-defined multifunctional brush-type polymeric prodrug covalently linked with an anticancer drug (bufalin, BUF), a tumor-targeting peptide (RGD), and an endosome-escaping polymer, poly(N,N-diethylaminoethyl methacrylate-co-butyl methacrylate (P(DEA-co-BMA)), was developed. Its anticancer performance against colon cancer was investigated in vitro and in vivo. Reversible addition-fragmentation transfer (RAFT) polymerization of oligo(ethylene glycol) monomethyl ether methacrylate (OEGMA), 2-((3-(tert-butoxy)-3-oxopropyl)thio)ethyl methacrylate (BSTMA), and 2-(2-bromoisobutyryloxy)ethylmethacrylate (BIEM) afforded the multifunctional random copolymer, P(OEGMA-co-BSTMA-co-BIEM), in which hydrophilic POEGMA can stabilize nanoparticles in water, PBSTMA can be converted into carboxyl groups, and PBIEM can be employed as a macromolecular atom radical transfer polymerization (ATRP) initiator. The ATRP of DEA and BMA using P(OEGMA-co-BSTMA-co-BIEM) as a macromolecular ATRP initiator led to the formation of the pH-responsive brush-type copolymer, P(OEGMA-co-BSTMA)-g-P(DEA-co- BMA). After hydrolysis by trifluoroacetic acid and post-functionalization the final polymeric prodrug, P(OEGMA-co-BUF-co-RGD)-g-P(DEA-co-BMA), was obtained with a drug content of ∼7.8 wt%. P(OEGMA-co-BUF-co-RGD)-g-P(DEA-co-BMA) can be assembled into nanoparticles (BUF- NP-RGD) in aqueous solution with a diameter of 148.4 ±â€¯0.7 nm and a zeta potential of -7.6 ±â€¯0.4 mV. BUF-NP-RGD exhibited controlled drug release in the presence of esterase. Additionally, P(OEGMA-co- BSMA)-g-P(DEA-co-BMA) showed a significant hemolysis effect at a pH comparable to that of endosomes/lysosomes. Cell viability and a tumor-bearing nude mouse model were employed to evaluate the anticancer efficacy of BUF-NP-RGD. It was revealed that BUF-NP-RGD showed improved anticancer performance compared with that of free BUF both in vitro and in vivo. Histological and immunochemical analysis further demonstrated that BUF-NP-RGD exhibited improved cell apoptosis, angiogenesis inhibition, and an anti-proliferation effect.


Assuntos
Bufanolídeos/química , Bufanolídeos/uso terapêutico , Polímeros/química , Pró-Fármacos/química , Pró-Fármacos/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Endossomos/metabolismo , Metacrilatos/química , Camundongos , Nanopartículas/química , Polietilenoglicóis/química
8.
Exp Ther Med ; 15(1): 1041-1047, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29434695

RESUMO

Fibroblast growth factor 21 (FGF21) as a member of the FGFs serves a key role in glucose homeostasis and protection of the liver, heart, kidney and skin from damage as well as cancer cell development. In addition, transcription of FGF21 is sensitive to diverse damages; however, the role of the transcriptional regulator of FGF21 in cancer cells remains to be elucidated. FGFs were identified to have dominant expression in cancer cells; therefore, mouse forestomach carcinoma (MFC) cells were used in the present study, which is a mouse stomach cancer cell strain for identifying the FGF21 regulators. In promoter analysis of FGF21, the putative transcription factor 4 (TCF4) binding motifs (T/AC/GAAAG) were observed within 1.5 kb of the promoter region. Further chromatin immunoprecipitation and yeast-one hybrid assays identified that TCF4 directly bound to one of the two putative binding motifs observed. A co-immunoprecipitation assay identified that ß-catenin interacts with TCF4 in MFC cells, and the ß-catenin/TCF4 complex bound to the promoter of FGF21. In order to examine the function of TCF4 and ß-catenin in transcriptional regulation of FGF21, TCF4 and ß-catenin was transiently expressed in MFC cells. Reverse transcription-quantitative polymerase chain reaction results revealed that overexpression of TCF4 and ß-catenin activated FGF21 transcription. Besides, suppression of ß-catenin via a specific short interfering RNA resulted in reduction of FGF21 expression. Together these findings suggest that the ß-catenin/TCF complex directly activates FGF21 via promoter binding. The observations of the present study may help elucidate the regulatory mechanism of FGF21, which is a key pharmaceutical protein.

10.
Behav Brain Res ; 341: 129-134, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29287910

RESUMO

Impulsivity associated with abnormal dopamine (DA) function has been observed in several disorders, including addiction. Choice impulsivity is the preference for small, immediate rewards over larger rewards after a delay, caused by excessive discounting of future rewards. Addicts have abnormally high discount rates and prefer the smaller rewards sooner. While impulsivity has been inversely correlated with DA D2 receptor (D2R) availability in the midbrain and striatum, it is difficult to mechanistically link the two, due to the diverse neuroanatomical localization of D2Rs, which are found throughout the brain, in many types of neurons and neuronal subcompartments. To determine if ventral tegmental area (VTA) D2R hypofunction is linked to impulsivity, we knocked down D2 receptors from the VTA, using an adeno-associated viral (AAV) vector that delivers short hairpin RNAs (shRNA) targeted against the D2R. The D2R knockdown is restricted to neurons whose cell bodies reside in the VTA, leaving postsynaptic D2Rs intact in the striatum, prefrontal cortex, and other mesocorticolimbic structures. Rats were trained in a delay-discounting task to assess impulsive choice until a stable discounting curve was obtained, and then received bilateral VTA infusions of the D2R shRNA or a scrambled control virus. Over the next six weeks, the discounting curve of the VTA D2R knockdown rats shifted to the left, indicating a preference for the smaller, immediate reward, whereas the curve for control rats remained stable and unchanged. Together these results demonstrate that a decrease in VTA D2Rs enhances choice impulsivity.


Assuntos
Desvalorização pelo Atraso/fisiologia , Comportamento Impulsivo/fisiologia , Receptores de Dopamina D2/deficiência , Área Tegmentar Ventral/metabolismo , Animais , Dependovirus/genética , Técnicas de Silenciamento de Genes , Vetores Genéticos , Masculino , Neurônios/metabolismo , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/metabolismo , Distribuição Aleatória , Ratos Sprague-Dawley , Receptores de Dopamina D2/genética , Recompensa
11.
Colloids Surf B Biointerfaces ; 159: 375-385, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28818782

RESUMO

Novel methods to improve the anticancer performance of 5-fluorouracil (5-FU) is quite necessary for clinical medicines. In the present work, we fabricated a novel type of mesoporous silica nanoparticles (MSNs)-based inorganic/organic hybrid nanoparticles covalently attached with poly(oligo(ethylene glycol) monomethyl ether methacrylate) (POEGMA) for improved stabilization and targeting peptide (RGD) for targeted delivery with the aim of improving the anticancer performance of 5-FU. Atom transfer radical polymerization (ATRP) initiator functionalized MSN (MSN-Br) was synthesized at first, which was followed by surface-initiated ATRP of water soluble OEGMA and carboxyl-containing monomer (2-succinyloxyethyl methacrylate, SEMA). Functionalization of RGD onto the hydrophilic P(OEGMA-co-SEMA) chains afforded the final hybrid nanoparticle, MSN-P(OEGMA-co-RGD). 5-FU can be effectively loaded into the meso-pores of MSN-P(OEGMA-co-RGD) (5-FU@MSN-RGD) with drug content ∼7.5wt%. And the dynamic diameter (Dh) and zeta potential (ζ) of 5-FU@MSN-RGD were determined to be 199.3±5.4nm and -8.7±0.5mV, respectively. It was demonstrated that MSN-P(OEGMA-co-RGD) exhibited improved internalization into colon cancer cells and enhanced accumulation in tumor tissues. In addition, compared with free 5-FU, 5-FU@MSN-RGD showed enhanced anticancer efficacy both in vitro and in vivo, implying promising clinical applications.


Assuntos
Fluoruracila/farmacologia , Nanopartículas/química , Dióxido de Silício/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo , Sistemas de Liberação de Medicamentos/métodos , Fluoruracila/química , Humanos , Interações Hidrofóbicas e Hidrofílicas
12.
Psychopharmacology (Berl) ; 234(22): 3299-3307, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28825118

RESUMO

RATIONALE: Recent research has established the imidazoline I2 receptor as a promising target for the development of novel analgesics. However, despite an increasing understanding of imidazoline I2 receptor-mediated behavioral effects, little is known about post-I2-receptor signaling mechanisms. OBJECTIVE: This study examined the effects of several inhibitors of Ca2+ signaling mechanisms on two behavioral effects of the prototypical imidazoline I2 receptor ligand 2-(2-benzofuranyl)-2-imidazoline (2-BFI). METHODS: The von Frey filament test was used to examine the antinociceptive effects of 2-BFI in complete Freund's adjuvant (CFA)-induced inflammatory pain in rats. A two-lever drug discrimination paradigm in which rats were trained to discriminate 5.6 mg/kg (intraperitoneally) 2-BFI from its vehicle was used to examine the discriminative stimulus effects of 2-BFI. RESULTS: The L-type Ca2+ channel blockers verapamil and nimodipine, the calmodulin antagonist W-7, and the internal Ca2+ release inhibitor ryanodine all attenuated the antinociceptive effects of 2-BFI. Oxycodone- and acetaminophen-induced antinociception was unaffected by pretreatment with the Ca2+ channel blockers. Rats learned to reliably discriminate 5.6 mg/kg 2-BFI from saline. The I2 receptor agonists BU224, RS45041, tracizoline, and CR4056 all fully substituted for 5.6 mg/kg 2-BFI while idazoxan, S22687, 2,5-dimethoxy-4-methylamphetamine (DOM), and phenyzoline produced partial or no substitution. Verapamil, nimodipine, and W-7 did not alter the discriminative stimulus effects of 2-BFI. CONCLUSION: These results indicate that the antinociceptive effects of 2-BFI involve intracellular Ca2+ elevation and/or downstream Ca2+/calmodulin signaling, whereas the discriminative stimulus effects of 2-BFI are mediated by a distinct, independent mechanism.


Assuntos
Analgésicos/farmacologia , Benzofuranos/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Aprendizagem por Discriminação/efeitos dos fármacos , Imidazóis/farmacologia , Receptores de Imidazolinas/agonistas , Analgésicos/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Injeções Intraperitoneais , Masculino , Limiar da Dor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
13.
Oncol Rep ; 38(3): 1420-1430, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28731184

RESUMO

Drug resistance is an obstacle to chemotherapy in tumor patients. Recent studies have shown that the high stemness of cancer cells may be induced by chemotherapeutic drugs, which is correlated with drug resistance. In the present study, we investigated the effects of bufalin on the stemness of colorectal cancer. We found that cisplatin could induce high stemness through the tumorsphere formation assay in vitro and in vivo in the colorectal cancer cell lines HCT116 and LoVo. In addition, cisplatin-treated tumorsphere cells showed drug­resistant properties. These results suggested that acquired drug resistance induced by cisplatin in colorectal cancer cells occurred via high stemness. On assessing the effects of bufalin, a traditional Chinese medicine monomer, we found that it could reverse the high stemness and drug resistance induced by cisplatin in colorectal cancer. These findings suggest that bufalin plays an adjuvant role in colorectal cancer chemotherapy and may help reverse acquired drug resistance. These findings may aid in the development of new therapeutic strategies.


Assuntos
Bufanolídeos/administração & dosagem , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Células HCT116 , Humanos , Transdução de Sinais/efeitos dos fármacos
14.
Gene ; 627: 563-568, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28698158

RESUMO

Pigment epithelium-derived factor (PEDF) is a multifunctional secreted protein which plays important role in anti-angiogenic, anti-tumorigenic, as well as involves in the metabolism and regeneration of bone. In this study, our aim is to investigate the role of PEDF in regulating mineralization of osteoblasts from diabetic patients (DP). We isolated and cultured osteoblasts derived from DP and non-diabetic patients (NDP), in order to analyze the variable differences via gene expression and calcification assay in vitro. Gene expression analysis and alizarin red S staining revealed that osteoblasts from DP exhibited defective mineralization. PEDF and vascular endothelial growth factor (VEGF) levels were lower in osteoblasts from DP than those from NDP. Interestingly, exogenous PEDF could upregulate the gene expression levels of VEGF and osteoblast-related genes, further to restore mineralization ability in osteoblasts from DP. Our results demonstrated that PEDF played a positive role in maintaining bone development in diabetic osteoblasts, therefore, we confidently believe that PEDF may be a promising cytokine to consider in development of treatments for diabetic bone diseases.


Assuntos
Calcificação Fisiológica , Diabetes Mellitus/metabolismo , Proteínas do Olho/farmacologia , Fatores de Crescimento Neural/farmacologia , Osteoblastos/metabolismo , Serpinas/farmacologia , Estudos de Casos e Controles , Diferenciação Celular , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Humanos , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteocalcina/genética , Osteocalcina/metabolismo , Serpinas/genética , Serpinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
15.
Oncotarget ; 8(29): 48012-48026, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28624793

RESUMO

Multidrug resistance (MDR), mainly mediated by ABCB1 transporter, is a major cause for chemotherapy failure. Bufalin (BU), an active component of the traditional Chinese medicine chan'su, has been reported to have antitumor effects on various types of cancer cells. The purpose of this present study was to investigate the reversal effect of BU on ABCB1-mediated multidrug resistance in colorectal cancer. BU at safe concentration (5, 10, 20 nM) could reverse chemosensitivity of ABCB1-overexpression HCT8/ADR, LoVo/ADR and HCT8/ABCB1 nearly back to their parental cells level. In addition, results from the drug accumulation studies revealed that BU was able to enhance intracellular accumulation of doxorubicin (DOX) and Rhodamine 123 (Rho-123) in a dose-dependent manner. Furthermore, Western blot assays showed that BU significantly inhibited the expression level of ABCB1 protein. Meanwhile, BU stimulated the ATPase activity of ABCB1, which suggested that BU might be a substrate of ABCB1. More interestingly, docking analysis predicted that BU could be docked into the large hydrophobic drug-binding cavity of human ABCB1. Importantly, BU remarkable increased the effect of DOX against the ABCB1 resistant HCT8/ADR colorectal cell xenografts in nude mice, without inducing any obvious toxicity. Overall, we concluded that BU efficiently reversed ABCB1-mediated MDR through not only inhibited the efflux function of ABCB1, but also down-regulate its protein expression, which might represent a potential and superior ABCB1 modulator in colorectal cancer.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Antineoplásicos/farmacologia , Bufanolídeos/farmacologia , Neoplasias Colorretais/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Animais , Antineoplásicos/química , Bufanolídeos/química , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Oncotarget ; 8(13): 21719-21732, 2017 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-28423513

RESUMO

The development of multidrug-resistance (MDR) is a major contributor to death in colorectal carcinoma (CRC). Here, we investigated the possible role of microRNA (miR)-503-5p in drug resistant CRC cells. Unbiased microRNA array screening revealed that miR-503-5p is up-regulated in two oxaliplatin (OXA)-resistant CRC cell lines. Overexpression of miR-503-5p conferred resistance to OXA-induced apoptosis and inhibition of tumor growth in vitro and in vivo through down-regulation of PUMA expression. miR-503-5p knockdown sensitized chemoresistant CRC cells to OXA. Our studies indicated that p53 suppresses miR-503-5p expression and that deletion of p53 upregulates miR-503-5p expression. Inhibition of miR-503-5p in p53 null cells increased their sensitivity to OXA treatment. Importantly, analysis of patient samples showed that expression of miR-503-5p negatively correlates with PUMA in CRC. These results indicate that a p53/miR-503-5p/PUMA signaling axis regulates the CRC response to chemotherapy, and suggest that miR-503-5p plays an important role in the development of MDR in CRC by modulating PUMA expression.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias Colorretais/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas/metabolismo , Adulto , Idoso , Animais , Western Blotting , Resistência a Múltiplos Medicamentos/genética , Feminino , Células HCT116 , Células HT29 , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase
17.
J Cell Biochem ; 118(11): 3932-3942, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28402022

RESUMO

Steroidogenic acute regulatory protein (StAR), a mitochondrial cholesterol delivery protein, plays a beneficial role in hyperlipidemia, NAFLD, and endothelial inflammation. Elevated circulating fatty acids and low grade inflammation are known as key risk factors of insulin resistance and type 2 diabetes. In the present study, C57BL/6J mice were fed with HFD and infected with recombinant adenovirus expressing StAR by tail-vein injection. Intraperitoneal glucose/insulin tolerance test was performed to assess the insulin sensitivity. Morphological analysis and intramuscular lipid determination were used to illustrate the adipose hypertrophy and ectopic fat accumulation in skeletal muscle. The levels of inflammatory factor and nitric oxide were determined by ELISA and classic Griess reagent methods, respectively. The fatty acids composition was analysis using gas chromatography-mass spectrometry (GC-MS). The expression of genes associated with inflammation and insulin resistance were determined by Western blotting and qPCR to elucidate the underlying mechanism. We demonstrated that StAR overexpression ameliorated insulin resistance and systemic inflammatory response with the reduction of adipose hypertrophy and intramuscular lipid in HFD-fed mice. In addition, StAR overexpression increased serum unsaturated fatty acids (UFAs) and PPARγ expression in muscle and adipose tissue of obese mice. In conclusion, StAR may activate PPARγ by increasing UFAs, which leads to a protective role in systemic inflammation and insulin resistance in obese mice. J. Cell. Biochem. 118: 3932-3942, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Gorduras na Dieta/efeitos adversos , Resistência à Insulina , Obesidade/metabolismo , Fosfoproteínas/biossíntese , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Gorduras na Dieta/farmacologia , Ácidos Graxos Insaturados/sangue , Inflamação , Masculino , Camundongos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Ácido Nítrico/sangue , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/patologia , PPAR gama/genética , PPAR gama/metabolismo , Fosfoproteínas/genética
18.
Oncol Rep ; 37(3): 1815-1825, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28184922

RESUMO

Cinobufagin (CBF) is isolated from the skin and posterior auricular glands of the Asiatic toad (Bufo gargarizans). This study investigated the reversal effect of CBF on P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) in colon cancer. The effect of CBF on the cytotoxicity of anticancer drugs in P-gp overexpressing LoVo/ADR, HCT116/L, Cao-2/ADR cells and their parental cells was determined using CCK-8 assay. Apoptosis of anti-cancer drugs and accumulation of doxorubicin (DOX) and Rhodamine 123 (Rho123) in P-gp overexpressing cells were evaluated by flow cytometry. Results indicated that CBF significantly enhanced the sensitivity of P-gp substrate drugs on P-gp overexpressing cells, but had no effect on their parental cells. CBF enhanced the effect of DOX against P-gp-overexpressing LoVo/ADR cell xenografts in nude mice. Moreover, CBF also increased cell apoptosis of chemotherapy agents and intracellular accumulation of DOX and Rho123 in the MDR cells. Further research on the mechanisms revealed non-competitive inhibition of P-gp ATPase activity, but without altering the expression of P-gp. These findings demonstrated that CBF could be further developed into a safe and potent P-gp modulator for combination use with anticancer drugs in cancer chemotherapy.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Bufanolídeos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Animais , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Doxorrubicina/farmacologia , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Biochim Biophys Acta Mol Basis Dis ; 1863(4): 978-990, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28153708

RESUMO

Non-alcoholic fatty liver disease (NAFLD) covers a wide spectrum of liver pathology. Intracellular lipid accumulation is the first step in the development and progression of NAFLD. Steroidogenic acute regulatory protein (StAR) plays an important role in the synthesis of bile acid and intracellular lipid homeostasis and cholesterol metabolism. We hypothesize that StAR is involved in non-alcoholic fatty liver disease (NAFLD) pathogenesis. The hypothesis was identified using free fatty acid (FFA)-overloaded NAFLD in vitro model and high-fat diet (HFD)-induced NAFLD mouse model transfected by recombinant adenovirus encoding StAR (StAR). StAR expression was also examined in pathology samples of patients with fatty liver by immunohistochemical staining. We found that the expression level of StAR was reduced in the livers obtained from fatty liver patients and NAFLD mice. Additionally, StAR overexpression decreased the levels of hepatic lipids and maintained the hepatic glucose homeostasis due to the activation of farnesoid x receptor (FXR). StAR overexpression attenuated the impairment of insulin signaling in fatty liver. This protective role of StAR was owing to a reduction of intracellular diacylglycerol levels and the phosphorylation of PKCε. Furthermore, FXR inactivation reversed the observed beneficial effects of StAR. The present study revealed that StAR overexpression can reduce hepatic lipid accumulation, regulate glucose metabolism and attenuate insulin resistance through a mechanism involving the activation of FXR. Our study suggests that StAR may be a potential therapeutic target for NAFLD.


Assuntos
Regulação da Expressão Gênica , Metabolismo dos Lipídeos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fosfoproteínas/metabolismo , Animais , Diglicerídeos/genética , Diglicerídeos/metabolismo , Feminino , Humanos , Resistência à Insulina , Masculino , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/terapia , Fosfoproteínas/genética
20.
Alcohol Clin Exp Res ; 40(7): 1531-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27184383

RESUMO

BACKGROUND: Major depression is one of the most prevalent psychiatry comorbidities of alcohol use disorders (AUD). As negative emotions can trigger craving and increase the risk of relapse, treatments that target both conditions simultaneously may augment treatment success. Previous studies showed a potential synergistic effect of Food and Drug Administration approved medication for AUD acamprosate and the antidepressant escitalopram. In this study, we investigated the effects of combining acamprosate and escitalopram on ethanol (EtOH) consumption in stress-induced depressed mice. METHODS: Forty singly housed C57BL/6J male mice were subjected to chronic unpredictable stress. In parallel, 40 group-housed male mice were subjected to normal husbandry. After 3 weeks, depressive- and anxiety-like behaviors and EtOH consumption were assessed. For the next 7 days, mice were injected with saline, acamprosate (200 mg/kg; twice/d), escitalopram (5 mg/kg; twice/d), or their combination (n = 9 to 11/drug group/stress group). Two-bottle choice limited-access drinking of 15% EtOH and tap water was performed 3 hours into dark phase immediately after the daily dark phase injection. EtOH drinking was monitored for another 7 days without drug administration. RESULTS: Mice subjected to the chronic unpredictable stress paradigm for 3 weeks showed apparent depression- and anxiety-like behaviors compared to their nonstressed counterparts including longer immobility time in the forced swim test and lower sucrose preference. Stressed mice also displayed higher EtOH consumption and preference in a 2-bottle choice drinking test. During the drug administration period, the escitalopram-only and combined drug groups showed significant reduction in EtOH consumption in nonstressed mice, while only the combined drug group showed significantly reduced consumption in stressed mice. However, such reduction did not persist into the postdrug administration period. CONCLUSIONS: The combination of acamprosate and escitalopram suppressed EtOH intake in both nonstressed and stressed mice; hence, this combination is potentially helpful for AUD individuals with or without comorbid depression to reduce alcohol use.


Assuntos
Consumo de Bebidas Alcoólicas/tratamento farmacológico , Citalopram/uso terapêutico , Taurina/análogos & derivados , Acamprosato , Animais , Ansiedade/complicações , Ansiedade/tratamento farmacológico , Depressão/complicações , Depressão/tratamento farmacológico , Quimioterapia Combinada , Masculino , Camundongos , Estresse Psicológico/tratamento farmacológico , Taurina/uso terapêutico
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