RESUMEN
Gastric cancer (GC) is a prominent cause of cancer-related mortality worldwide. Long noncoding RNA (lncRNA) maternal expression gene3 (MEG3) participates in numerous signaling pathways by targeting the miRNA-mRNA axis. Studies on human tumors have demonstrated that the antibiotic Ciprofloxacin induces cell cycle changes, programmed cell death, and growth suppression. In this study, we transfected MEG3 lncRNA and Ciprofloxacin into the MKN-45 GC cell line. qRT-PCR was employed to evaluate the effects on the specific microRNA and mRNA. The wound healing test, MTT assay, and flow cytometry were used to assess the impact of their administration on cell migration, viability, and apoptosis, respectively. Research showed that miR-147 expression fell even more after MEG3 lncRNA transfection, leading to an increase in B-cell lymphoma 2 (BCL-2) levels. Ciprofloxacin transfection did not significantly affect the axis, except for MEG3, which led to its slight upregulation. MEG3 lncRNA inhibited the migration of MKN-45 cells compared to the control group. When MEG3 lncRNA was coupled with Ciprofloxacin, there was a significant reduction in cell migration compared to untreated groups and controls. MTT assay and flow cytometry demonstrated that MEG3 lncRNA decreased cell viability and triggered apoptosis. Simultaneous administration of MEG3 lncRNA and Ciprofloxacin revealed a significant reduction in cell viability caused by increased apoptosis obtained from MTT or flow cytometry assays. Modulating the miR-147-BCL-2 axis decreases cell migration and survival while promoting cell death. In conclusion, combining MEG3 lncRNA with Ciprofloxacin may be an effective therapeutic approach for GC treatment by influencing the miR-14-BCl-2 axis, resulting in reduced cell viability, migration, and increased apoptosis.
Asunto(s)
Apoptosis , Movimiento Celular , Supervivencia Celular , Ciprofloxacina , ARN Largo no Codificante , Neoplasias Gástricas , Ciprofloxacina/farmacología , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias Gástricas/patología , Neoplasias Gástricas/genética , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/metabolismo , Línea Celular Tumoral , MicroARNs/genética , MicroARNs/metabolismoRESUMEN
RESEARCH QUESTION: What is the effect of vitamin D3 (1,25(OH)2D3) on proliferation, cell cycle and apoptosis of endometrial stromal cells (ESC) in endometriotic patients? DESIGN: ESC isolated from 10 women with endometriosis and 10 healthy controls were treated with 1,25(OH)2D3. The proliferation of control endometrial stromal cells (CESC), eutopic endometrial stromal cells (EuESC) and ectopic endometrial stromal cells (EESC) was analysed 72 h after the treatment using methyl thiazolyl tetrazolium assay. Propidium iodide staining and flow cytometry were used to determine the cell cycle distribution in ESC. Annexin V/propidium iodide double staining was used to evaluate apoptosis in ESC. RESULTS: In the presence of oestrogen, 1,25(OH)2D3 treatment inhibited the proliferation of ESC from all three origins (Pâ¯=â¯0.009 for CESC, P = 0.005 for EuESC and P < 0.001 for EESC). The percentage of S phase cells in EESC was higher than in EuESC and CESC (P = 0.002 and Pâ¯=â¯0.001, respectively). The percentage of S phase cells in EuESC was higher than in CESC (P = 0.005). The percentage of G1 phase cells in EESC was lower than that of EuESC and CESC (P = 0.003 and P = 0.002, respectively) and the percentage of G1 phase cells in EuESC was lower than that of CESC (P = 0.007). Moreover, 1,25(OH)2D3 inhibited cell cycle regardless of cell type (P = 0.002 in EESC, P = 0.001 in EuESC and P = 0.014 in CESC), but in the absence of oestrogen, inhibited cell cycle only in EuESC (P = 0.012). CONCLUSIONS: Although 1,25(OH)2D3 increased apoptotic and necrotic cells and decreased live cells in the EuESC and EESC, it did not affect apoptosis in CESC and only increased necrotic cells. These findings indicate that 1,25(OH)2D3 potentially has a growth-inhibiting and pro-apoptotic effect on ESC from endometriotic patients.
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Endometriosis , Vitamina D , Humanos , Femenino , Vitamina D/metabolismo , Endometriosis/metabolismo , Propidio/metabolismo , Propidio/farmacología , Ciclo Celular , División Celular , Apoptosis , Vitaminas , Estrógenos/metabolismo , Células del Estroma/metabolismo , Proliferación Celular , Endometrio/metabolismoRESUMEN
BACKGROUND: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. METHODS: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 µM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. RESULTS: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and ß-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 µM CoCl2. The gene expression of VEGF, vimentin, and ß-catenin and protein level of ß-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of ß-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. CONCLUSION: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Factor 1 Inducible por Hipoxia/metabolismo , Hipoxia/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Western Blotting , Expresión Génica , Células HEK293 , Humanos , Hipoxia/genética , Factor 1 Inducible por Hipoxia/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Activación Transcripcional/genéticaRESUMEN
Immunotherapy has improved cancer treatment based on investigations of tumor immune escape. Manipulation of the immune system stimulates antitumor immune responses and blocks tumor immune escape routes. Genetically adoptive cell therapy, such as T cells, has yielded promising results for hematologic malignancies, but their application to solid tumors has been challenging. Macrophages have a wide broad of capabilities in regulating immune responses, homeostasis, and tissue development, as well as the ability to phagocyte, present antigens, and infiltrate the tumor microenvironment (TME). Given the importance of macrophages in cancer development, they could serve as novel tool for tumor treatment. Therefore, macrophages are used in different formats for direct and indirect targeting of tumor cells. This review summarized the available data on the various applications of macrophages in cancer immunotherapy.
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Inmunoterapia , Macrófagos , Neoplasias , Microambiente Tumoral , Humanos , Neoplasias/inmunología , Neoplasias/terapia , Macrófagos/inmunología , Animales , Inmunoterapia/métodos , Microambiente Tumoral/inmunología , Escape del Tumor/inmunología , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismoRESUMEN
Researchers have tried to find novel strategies for cancer treatment in the past decades. Among the utilized methods, administering oncolytic viruses (OVs) alone or combined with other anticancer therapeutic approaches has had promising outcomes, especially in solid tumors. Infecting the tumor cells by these viruses can lead to direct lysis or induction of immune responses. However, the immunosuppressive tumor microenvironment (TME) is considered a significant challenge for oncolytic virotherapy in treating cancer. Based on OV type, hypoxic conditions in the TME can accelerate or repress virus replication. Therefore, genetic manipulation of OVs or other molecular modifications to reduce hypoxia can induce antitumor responses. Moreover, using OVs with tumor lysis capability in the hypoxic TME may be an attractive strategy to overcome the limitations of the therapy. This review summarizes the latest information available in the field of cancer virotherapy and discusses the dual effect of hypoxia on different types of OVs to optimize available related therapeutic methods.
Asunto(s)
Neoplasias , Viroterapia Oncolítica , Virus Oncolíticos , Humanos , Neoplasias/patología , Virus Oncolíticos/genética , Microambiente Tumoral , Replicación ViralRESUMEN
OBJECTIVE: The goal of treatment in palindromic rheumatism (PR) is to control the attacks and prevent disease evolution to chronic arthritis. Conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) including antimalarial and methotrexate cannot control attacks in all patients. METHODS: In this retrospective study, we assessed the efficacy of leflunomide in patients with PR who had an inadequate response to DMARDs. In this study, patients who had a diagnosis of PR and were treated with leflunomide because of active disease despite treatment with csDMARDs for at least 6 months were included. Remission was defined as no attacks for 3 months and prednisolone dose ≤5 mg/d. Leflunomide treatment failure was defined as failure to achieve remission, the need to add other DMARDs for controlling attacks and disease progression to chronic arthritis during treatment with leflunomide. RESULTS: Ten cases with active disease despite treatment with hydroxychloroquine and methotrexate and low-dose prednisolone treated with leflunomide were included in the study. During the 12.6 ± 7.5 months of treatment with leflunomide, the frequency of attacks significantly decreased. Complete and partial remission were achieved in 90% of patients. CONCLUSION: Our results indicate that leflunomide controls PR attacks and it might be a new option for patients with PR.
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Antirreumáticos , Artritis Reumatoide , Antirreumáticos/efectos adversos , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/tratamiento farmacológico , Quimioterapia Combinada , Humanos , Leflunamida/efectos adversos , Metotrexato/efectos adversos , Prednisolona/uso terapéutico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Hypoxia is a common characteristic of the tumor microenvironment. In response to hypoxia, expression of the hypoxia-inducible factor (HIF) can lead to activation of downstream molecular events such as epithelial-mesenchymal transition (EMT), invasion, and angiogenesis. In this study, CoCl2 was used to simulate hypoxia in SKBR3 and HEK293T cell lines to investigate whether this treatment can induce hypoxia-associated EMT and invasion in the studied cells. SKBR3 and HEK293T cells were treated with different concentrations of CoCl2 at different exposure times and their viability was analyzed. To confirm successful hypoxia induction, the expression levels of HIF1α and vascular endothelial growth factor A (VEGFA) mRNA were assessed. Additionally, the expression of EMT-associated markers including snail, E-cadherin, N-cadherin, and vimentin, as well as invasion-related genes including matrix metalloproteinase-2 (MMP2) and MMP9 was measured. We found that cell viability in CoCl2-treated cells was concentration-dependent and was not affected at low doses. While the expression of HIF and VEGFA genes was upregulated following hypoxia induction. E-cadherin expression was significantly downregulated in HEK293T cells; while, N-cadherin and snail were upregulated in both cell lines. Moreover, an increment of MMP expression was only observed in SKBR3 cells. Taken together, the findings indicated that CoCl2 can mimic hypoxia in both cell lines, but EMT was triggered in SKBR3 cells more effectively than in HEK293T cells, and invasion was only stimulated in SKBR3 cells. In conclusion, SKBR3 cancer cells can be used as an EMT model to better understand its control and manipulation mechanisms and to investigate new therapeutic targets for the suppression of tumor metastasis.
Asunto(s)
Transición Epitelial-Mesenquimal , Metaloproteinasa 2 de la Matriz , Cadherinas/genética , Cadherinas/metabolismo , Cadherinas/farmacología , Hipoxia de la Célula , Línea Celular Tumoral , Movimiento Celular , Cobalto/metabolismo , Cobalto/farmacología , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Hipoxia/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , ARN Mensajero/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Vimentina/genética , Vimentina/metabolismo , Vimentina/farmacologíaRESUMEN
Tumor-infiltrating lymphocytes (TILs), frontline soldiers of the adaptive immune system, are recruited into the tumor site to fight against tumors. However, their small number and reduced activity limit their ability to overcome the tumor. Enhancement of TILs number and activity against tumors has been of interest for a long time. A lack of knowledge about the tumor microenvironment (TME) has limited success in primary TIL therapies. Although the advent of engineered T cells has revolutionized the immunotherapy methods of hematologic cancers, the heterogeneity of solid tumors warrants the application of TILs with a wide range of specificity. Recent advances in understanding TME, immune exhaustion, and immune checkpoints have paved the way for TIL therapy regimens. Nowadays, TIL therapy has regained attention as a safe personalized immunotherapy, and currently, several clinical trials are evaluating the efficacy of TIL therapy in patients who have failed conventional immunotherapies. Gaining favorable outcomes following TIL therapy of patients with metastatic melanoma, cervical cancer, ovarian cancer, and breast cancer has raised hope in patients with refractory solid tumors, too. Nevertheless, TIL therapy procedures face several challenges, such as high cost, timely expansion, and technical challenges in selecting and activating the cells. Herein, we reviewed the recent advances in the TIL therapy of solid tumors and discussed the challenges and perspectives.
Asunto(s)
Melanoma , Neoplasias Ováricas , Femenino , Humanos , Linfocitos Infiltrantes de Tumor , Inmunoterapia , Linfocitos T/patología , Microambiente TumoralRESUMEN
BACKGROUND: Endothelin-1 (ET-1) is a peptide overexpressed in gastric cancer (GC) and linked to carcinogenesis and resistance to chemotherapy. Applying microRNAs (miRNAs/miRs) to downregulate ET-1 and reverse resistance to commonly used chemotherapy drugs such as 5-fluorouracil (5-FU) is practical. METHODS: The current study sought to evaluate the miR-648 expression in GC and any plausibility of its replacement, either with or without the combination of chemo agents to downregulate ET-1 expression through interaction with its target gene. To this end, miR-648 and ET-1 expression levels were assessed in GC tissues and adjacent non-tumor tissues driven from 65 patients who had already undergone surgery, fifteen of which had received 5-FU before surgery. The impact of miR-648 and chemo agents on ET-1 expression was measured using qPCR and Western blotting. Further, an MTT assay was conducted to assess its association with cell viability. Ultimately, the association of miR-648 and ET-1 with clinicopathological characteristics was evaluated. RESULTS: The current study revealed that miR-648 was considerably down-regulated, while ET-1 was substantially up-regulated in patients with GC. The 5-FU caused a significant increase in miR-648 and reduced ET-1 expression. It was also determined that overexpression of miR-648 suppressed ET-1 production, notably when combined with 5-FU, leading to survival reduction. These results further showed that miR-648 replacement could sensitize chemoresistant GC cells. Besides, a significant association between ET-1 and miR-648 with clinicopathological features was discovered CONCLUSIONS: miR-648 replacement may serve as a potential oncosuppressive therapeutic approach that warrants further investigation to translate into an effective GC treatment.
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MicroARNs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Endotelina-1/genética , Endotelina-1/metabolismo , Endotelina-1/farmacología , Regulación Neoplásica de la Expresión Génica/genética , Resistencia a Antineoplásicos/genética , Línea Celular Tumoral , Fluorouracilo/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Proliferación CelularRESUMEN
Endometriosis is a chronic inflammatory disease that has been reported to be associated with immune system dysfunction. On the other hand, the effect of Vitamin D as an immune modulator and its relation with several autoimmune and inflammatory diseases has been previously investigated. Moreover, several studies have reported the polymorphisms of VDR and VDBP genes can change the functions of these molecules. Therefore, these polymorphisms may be influential on endometriosis pathogenesis. In this study, we aimed at evaluating the association between VDR gene (FokI (F/f), BsmI (B/b), ApaI (A/a), TaqI (T/t)), and VDBP gene (GC*1S, GC*1F, and GC*2) polymorphisms with endometriosis in Iranian women population. This case-control study was performed on 120 women with endometriosis and 110 healthy women. ARMS-PCR and PCR-RFLP methods were used to inspect polymorphisms in VDR and VDBP genes, respectively. Based on the results, there was no statistically significant difference between the cases with endometriosis and control subjects in terms of genotypes and allele frequencies of VDR and VDBP gene polymorphisms. These data suggest that VDR and VDBP gene polymorphisms may have no role in endometriosis susceptibility in Iranian women.
Asunto(s)
Endometriosis/genética , Estudios de Asociación Genética/métodos , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Calcitriol/genética , Proteína de Unión a Vitamina D/genética , Adulto , Estudios de Casos y Controles , Endometriosis/diagnóstico , Endometriosis/epidemiología , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Infertilidad Femenina/diagnóstico , Infertilidad Femenina/epidemiología , Infertilidad Femenina/genética , Irán/epidemiologíaRESUMEN
Interleukin-10 (IL-10) is a pleiotropic cytokine, which has both regulatory and stimulatory effects on different immune cell types. Different studies have reported the importance of IL-10 and Transforming growth factor-beta (TGF-ß) in the regulation of B cell class switching the production of immunoglobulin A (IgA); however, the underlying mechanisms remain to be fully elucidated. The objective of this study was to investigate the TGF-ß response during B stimulation of human B cells by IL-10. Pan B cells of healthy donors were negatively purified by a magnetic cell separation technique. B cells were cultured with multimeric CD40 ligand (mCD40L) and IL-10 for two and seven days. After harvesting in specific days, TGF-ß receptor II and surface IgA expression was determined by flow cytometry, while IgA and TGF-ß secretion was assessed by enzyme-linked immunosorbent assay. B cells endogenously expressed TGF-ß receptor II and after 48 hours cultivation with mCD40L or mCD40L plus IL-10, both the expression of this receptor and the production of TGF-ß were significantly increased. Notably, TGF-ß levels following stimulation with mCD40L and IL-10 were higher than those produced by B cells stimulated with mCD40L alone. Furthermore, at day 7 and following IL-10 stimulation, there was a significant rise in the amount of IgA secretion by class-switched plasma cells, which was higher than stimulation with mCD40L alone. Our findings suggest that IL-10 can modulate TGF-ß production and TGF-ß receptor expression in mCD40-activated human B lymphocytes.
Asunto(s)
Linfocitos B/inmunología , Inmunoglobulina A/inmunología , Interleucina-10/inmunología , Receptores de Factores de Crecimiento Transformadores beta/inmunología , Factor de Crecimiento Transformador beta/inmunología , Regulación hacia Arriba/inmunología , Antígenos CD40/inmunología , Ligando de CD40/inmunología , Humanos , Cambio de Clase de Inmunoglobulina/inmunología , Activación de Linfocitos/inmunologíaRESUMEN
This investigation is performed to evaluate the impact of static magnetic field on the Cell growth alignment, and differentiation potential in Human Mesenchymal Stem cells derived from human newborn cords. In vitro-cultured mesenchymal stem cells derived from human newborn cords were exposed to SMF up to 24 mT and compared with the control (unexposed) cultures. Viability was assessed via Trypan Blue staining and MTT assay. Cell cycle progression was studied after flow cytometry data analysis. Sox-2, Nanong, and Oct-4 Primers used for RT-PCR experiment. Morphological studies showed that the exposed cells were significantly aligned in parallel bundles in a correlation with the magnetic field lines. Viability measurements showed a significant reduction in cell viability which was noted after exposure to static magnetic field and initiated 36 h after the end of exposure time. Flow cytometric data analysis confirmed a decrease in G1 phase cell population within the treated and cultured groups compared with the corresponding control samples. However, the induced changes were recovered in the cell cultures after the post-exposure culture recovery time which may be attributed to the cellular repair mechanisms. Furthermore, the proliferation rate and Oct-4 gene expression were reduced due to the 18 mT static magnetic field exposure. The significant proliferation rate decrease accompanied by the Sox-2, Nanong, and Oct-4 gene expression decline, suggested the differentiation inducing effects of SMF exposure. Exposure to Static Magnetic fields up to 24 mT affects mesenchymal stem cell alignment and proliferation rate as well as mRNA expression of Sox-2, Nanong, and Oct-4 genes, therefore can be considered as a new differentiation inducer in addition to the other stimulators.
RESUMEN
T-cell immunoglobulin and mucin domain (TIM)-3 have been shown to negatively regulate Th1 cell-mediated immunity. Activation of TIM-3 by galectin-9 induces Th1 cell apoptosis, which may contribute to skewing of immune response towards Th2-dominant immunity. The aim of this study was to determine whether certain genetic variations of TIM-3 influence predisposition to asthma in a sample of Iranian population. This case-control study was conducted on 209 patients with asthma and 200 healthy controls. The +4259 T>G and -574 G>T polymorphisms were detected using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and amplification refractory mutation system-PCR(ARMS-PCR). Total serum IgE was further measured with ELISA. Notably, +4259T > G and-574G>T polymorphisms of TIM-3 were significantly associated with the susceptibility to asthma. In addition, the present study showed a significant difference between the distribution frequency of the GT + TT genotype and T allele on the +4259 T>G and -574 G>T locus between the groups.However, no correlation between the +4259 T > G and -574G > T polymorphisms and total serum IgE levels were observed. Together these results suggest that the TIM-3 +4259 T>G and -574 G>T polymorphisms are greatly associated with the susceptibility of Iranian population to asthma, which could open up new horizons for better understanding of the pathophysiology, diagnostic, prognostic and therapeutic approaches of asthma.
Asunto(s)
Alelos , Asma/epidemiología , Asma/genética , Predisposición Genética a la Enfermedad , Receptor 2 Celular del Virus de la Hepatitis A/genética , Polimorfismo de Nucleótido Simple , Adulto , Asma/inmunología , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Genotipo , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Irán/epidemiología , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Factores de RiesgoRESUMEN
BACKGROUND: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. METHODS: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 µM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. RESULTS: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and ß-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 µM CoCl2. The gene expression of VEGF, vimentin, and ß-catenin and protein level of ß-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of ß-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. CONCLUSION: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor.