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BACKGROUND: The effect of human 8-Oxoguanine DNA Glycosylase (hOGG1) on exogenous chemicals in esophageal squamous cell carcinoma (ESCC) remain unclear. The study plans to determine hOGG1 expression levels in ESCC and possible interactions with known environmental risk factors in ESCC. MATERIAL AND METHODS: We analyzed levels of exposure to urinary nitrosamines in volunteers from high and low prevalence areas by GC-MS. And we performed the interaction between hOGG1 gene and nitrosamine disinfection by-products by analyzing hOGG1 gene expression in esophageal tissues. RESULTS: In ESCC, nitrosamine levels were significantly increased and hOGG1 mRNA expression levels were significantly decreased. There was a statistically significant interaction between reduced hOGG1 mRNA levels and non-tap drinking water sources in ESCC. The apparent indirect association between ESCC and NMEA indicated that 33.4% of the association between ESCC and NMEA was mediated by hOGG1. CONCLUSION: In populations which exposed to high levels of environmental pollutants NDMA, low expression of hOGG1 may promote the high incidence of esophageal cancer in Huai'an. hOGG1 may be a novel mediator in nitrosamine-induced esophageal tumorigenesis.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Nitrosaminas , Humanos , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/induzido quimicamente , Carcinoma de Células Escamosas do Esôfago/complicações , Nitrosaminas/toxicidade , Transformação Celular Neoplásica , RNA MensageiroRESUMO
Esophageal squamous cell carcinoma (ESCC) is a malignant tumor with high mortality and poor prognosis. Despite intensive research focused on tumor suppression, the 5-year survival rate of ESCC is lower than 15%. Therefore, investigate fundamental mechanisms involved in ESCC is on-demand crucial for diagnostics and developing targeted therapeutic drugs. Circular RNAs (circRNAs), as an emerging class of non-coding RNA, have been elucidated that circRNAs participated in regulating a variety of pathological processes and tumorigenesis. Nevertheless, the functional role of circRNAs in the occurrence and development of ESCC remains unclear. We identify a novel circRNA (hsa_circ_0001707), which was highly expressed in ESCC patients' tissues and cell lines. Furthermore, gain- and loss-of-function assays were performed and found that overexpression of hsa_circ_0001707 significantly promote tumor proliferation, metastasis, and invasion. By functioning as a competing endogenous RNA (ceRNA), the dual-luciferase activity assay verified that hsa_circ_0001707 can endogenously bind with miR-203a-3p and regulate its downstream gene Snail2. Rescue assay further confirms that hsa_circ_0001707 downregulation could partially attenuate the facilitation effect of miR-203a-3p, thereby inhibiting the endothelial-mesenchymal transition (EMT) process of ESCC. Our results suggested that hsa_circ_0001707 play an oncogenic role in the pathogenesis of ESCC, which might be a potential biomarker for diagnostics and targeting therapy.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , MicroRNAs , Humanos , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , MicroRNAs/genética , RNA Circular/genética , Neoplasias Esofágicas/patologia , Transição Endotélio-Mesênquima , Proliferação de Células/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão GênicaRESUMO
Background: Postoperative outcomes for patients suffering from resectable esophageal squamous cell carcinoma (ESCC) are related to sarcopenia. In patients with resectable ESCC, this study investigated the link between sarcopenia and postoperative pneumonia. Methods: The McKewon procedure was the only one used to treat resectable ESCC patients from January 2018 to December 2021 in this retrospective analysis. Sarcopenia was assessed using skeletal muscles at L3 and planning CT scans. It was defined when PMI was below 6.36 cm2/m2 and 3.92 cm2/m2 for men and women, separately. Analyses of multivariate and univariate logistic regression were applied for identifying the risk factors for postoperative pneumonia. Results: The study included 773 patients with resectable ESCC in total. Sarcopenia was an independent risk factor for postoperative pneumonia in individuals with resectable ESCC based on univariate and multivariate analysis (P < 0.05). The stratified analysis indicated that neither of the clinical outcomes in the logistic regression model were affected by gender, age, BMI, smoking, or pre-albumin (P for interaction > 0.006). Conclusion: Following the McKewon procedure, patients with resectable ESCC who were sarcopenic had a higher postoperative pneumonia rate. To prevent the development of postoperative pneumonia during the perioperative period, it may be important to control the incidence of sarcopenia.
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It was previously believed that the microbial community in the esophagus was relatively stable, but it has been reported that different esophageal diseases have different microbial community characteristics. In this study, we recruited patients with esophageal squamous cell carcinoma (ESCC) and collected 51 pairs of tumor and adjacent non-tumor tissues for full-length 16S rDNAsequencing and qPCR to compare the differences in microbial community structure. The results of sequencing in 19 pairs of tissues showed that Proteobacteria, Firmicutes, Bacteroidetes, Deinococcus-Thermus, and Actinobacteria were the main bacteria in tumor and adjacent non-tumor tissues. At the genus level, the bacteria with the highest relative proportion in tumor and adjacent non-tumor tissues were Streptococcus and Labrys, respectively. At the same time, it was observed that the complexity of microbial interactions in tumor tissues was weaker than that of adjacent non-tumor tissues. The results also found that the relative abundance of 24 taxa was statistically different between tumor and adjacent non-tumor tissues. The findings of qPCR in 32 pairs of tissues further evidence that the relative proportions of Blautia, Treponema, Lactobacillus murinus, Peptoanaerobacter stomatis, and Fusobacteria periodonticum were statistically different in tumor and adjacent non-tumor tissues. The findings of PIRCUSt2 indicated the lipopolysaccharide biosynthesis and biotin metabolism in the microbiome of cancer tissues are more significant. This study supplements the existing information on the structure, function, and interaction of microorganisms in the esophagus in situ and provides a direction for the further exploration of the relationship between esophageal in situ microorganisms and esophageal squamous cell carcinoma. KEY POINTS: ⢠The structure of the microbial community in esophageal cancer tissue and adjacent non-tumor tissues at the phylum level is similar ⢠Streptococcus and Labrys are the most important bacteria in esophageal tumor tissues and adjacent non-tumor tissues, respectively ⢠Microbial interactions in tumor tissues are stronger than in adjacent non-tumor tissues.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Microbiota , Bactérias/genética , DNA Ribossômico , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Humanos , Proteobactérias , StreptococcusRESUMO
Gut microbiota, especially human pathogens, has been shown to be involved in the occurrence and development of cancer. Esophageal squamous cell carcinoma and lung cancer are two malignant cancers, and their relationship with gut microbiota is still unclear. Virulence factor database (VFDB) is an integrated and comprehensive online resource for curating information about human pathogens. Here, based on VFDB database, we analyzed the differences of bacteria at genus level in the gut of patients with esophageal squamous cell carcinoma, lung cancer, and healthy controls. We proposed the possible cancer-associated bacteria in gut and put forward their possible effects. Apart from this, principal coordinate analysis (PCoA) and analysis of similarities (ANSOIM) suggested that some bacteria in the gut can be used as potential biomarkers to screen esophageal squamous cell carcinoma and lung cancer, and their effectiveness was preliminary verified. The relative abundance of Klebsiella and Streptococcus can be used to distinguish patients with esophageal squamous cell carcinoma and lung cancer from healthy controls. The absolute abundance of Klebsiella can further distinguish patients with esophageal squamous cell carcinoma from patients with lung cancer. In particular, the relative abundance of Fusobacterium can directly distinguish between patients with esophageal squamous cell carcinoma and healthy controls. Additionally, the absolute abundance of Haemophilus can distinguish lung cancer from healthy controls. Our study provided a new way based on VFDB database to explore the relationship between gut microbiota and cancer, and initially proposed a feasible cancer screening method.
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Bactérias/isolamento & purificação , Neoplasias Esofágicas/microbiologia , Microbioma Gastrointestinal , Neoplasias Pulmonares/microbiologia , Idoso , Bactérias/classificação , Bactérias/genética , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos PilotoRESUMO
A number of studies have identified that gut microbiota influences the development of cancer. However, there is little known about gut microbiota and esophageal cancer (EC). The aim of this study was to investigate the gut microbiota profile associated with EC. In this study, 23 patients with EC and 23 sex- and age-matched healthy controls (NC) were recruited between July 2019 and August 2019 at Huai'an First People's Hospital (Huai'an, China) and the gut microbiota was analyzed by 16S rRNA gene sequencing of fresh stool samples. We found that the microbial richness of intestinal flora in patients with EC were higher than NC, whereas evenness did not change obviously. Principal coordinate analysis (PCoA) and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) analysis both revealed that a distinct separation in bacterial community composition between the EC and NC. At the phylum level, the EC group showed significantly higher abundances of Firmicutes and Actinobacteria, but a lower Bacteroidetes than NC. At the genus level, a significantly increased abundance of Streptococcus, Bifidobacterium, Subdoligranulum, Blautia, Romboutsia, Collinsella, Paeniclostridium, Dorea, and Atopobium were observed in EC patients, while Lachnospira, Bacteroides, Agathobacter, Lachnoclostridium, Parabacteroides, Paraprevotella, Butyricicoccus, Tyzzerella, Fusicatenibacter, and Sutterella were reduced. Receiver operating characteristic (ROC) analysis revealed that Lachnospira, Bacteroides, Streptococcus, and Bifidobacterium both achieved a high accuracy in EC diagnosis (area under the curve was more than 0.85), and the Lachnospira was found to be the best classifier. This study firstly characterized the gut microbiota composition of EC patients and screened out the optimal potential microbiota biomarkers for EC diagnosis. It may provide a fundamental reference for further studies on the gut microbiome for the diagnosis and treatment of EC.
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Neoplasias Esofágicas , Microbioma Gastrointestinal , China , Disbiose , Fezes , Humanos , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Surgical resection is regarded as the only potentially curative treatment option for patients with metastatic colorectal cancer (CRC). The National Comprehensive Cancer Network clinical practice guidelines do not recommend palliative surgery unless there is a risk of severe symptoms. However, accumulating evidence has shown that palliative surgery is associated with more favorable outcomes for patients with metastatic CRC. AIM: To investigate the separate role of palliative primary tumor resection for patients with stage IVA (M1a diseases) and stage IVB (M1b diseases) colorectal adenocarcinoma (CRA). METHODS: CRA patients diagnosed from 2010 to 2015 with definite M1a and M1b categories according to the 8th edition of American Joint Committee on Cancer staging system were selected from the Surveillance Epidemiology and End Results (SEER) database. To minimize potential selection bias, the data were adjusted by propensity score matching (PSM). Baseline characteristics, including gender, year of diagnosis, age, marital status, primary site, surgical information, race, grade, chemotherapy, and radiotherapy, were recorded and analyzed. Univariate and multivariate analyses were performed to explore the separate role of palliative surgery for patients with M1a and M1b diseases. RESULTS: A total of 19680 patients with metastatic CRA were collected from the SEER database, including 10399 cases of M1a diseases and 9281 cases of M1b diseases. Common independent prognostic factors for both M1a and M1b patients included year of diagnosis, age, race, marital status, primary site, grade, surgery, and chemotherapy. After PSM adjustment, 3732 and 3568 matched patients in the M1a and M1b groups were included, respectively. Patients receiving palliative primary tumor resection had longer survival time than those without surgery (P < 0.001). For patients with M1a diseases, palliative resection could increase the median survival time by 9 mo; for patients with M1b diseases, palliative resection could prolong the median survival time by 7 mo. For M1a diseases, patients with lung metastasis had more clinical benefit from palliative resection than those with liver metastasis (15 mo for lung metastasis vs 8 mo for liver metastasis, P < 0.001). CONCLUSION: CRA patients with M1a diseases gain more clinical benefits from palliative primary tumor resection than those with M1b diseases. Those patients with M1a (lung metastasis) have superior long-term outcomes after palliative primary tumor resection.
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The neurotoxin MPP+ (1-methyl-4-phenylpyridinium ion) disrupts mitochondrial function leading to oxidative stress and neuronal death. Here we examine whether activation of the Keap1-Nrf2 cascade can protect SH-SY5Y neuroblastoma cells from MPP+-induced cytotoxicity. Treatment of SH-SY5Y cells with CBR-470-1, an inhibitor of the glycolytic enzyme phosphoglycerate kinase 1 (PGK1), leads to methylglyoxal modification of Keap1, Keap1-Nrf2 disassociation, and increased expression of Nrf2 responsive genes. Pretreatment with CBR-470-1 potently attenuated MPP+-induced oxidative injury and SH-SY5Y cell apoptosis. CBR-470-1 neuroprotection is dependent upon Nrf2, as Nrf2 shRNA or CRISPR/Cas9-mediated Nrf2 knockout, abolished CBR-470-1-induced SH-SY5Y cytoprotection against MPP+. Consistent with these findings, PGK1 depletion or knockout mimicked CBR-470-1-induced actions and rendered SH-SY5Y cells resistant to MPP+-induced cytotoxicity. Furthermore, activation of the Nrf2 cascade by CRISPR/Cas9-induced Keap1 knockout protected SH-SY5Y cells from MPP+. In Keap1 or PGK1 knockout SH-SY5Y cells,CBR-470-1 failed to offer further cytoprotection against MPP+. Collectively PGK1 inhibition by CBR-470-1 protects SH-SY5Y cells from MPP+ via activation of the Keap1-Nrf2 cascade.
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1-Metil-4-fenilpiridínio/toxicidade , Fator 2 Relacionado a NF-E2/agonistas , Fármacos Neuroprotetores/farmacologia , Síndromes Neurotóxicas/prevenção & controle , Fosfoglicerato Quinase/antagonistas & inibidores , Linhagem Celular Tumoral , Técnicas de Inativação de Genes , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/patologia , Fosfoglicerato Quinase/genética , Fosfoglicerato Quinase/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Esophageal carcinoma (EC) bears one of the most rapid-growing incidences in cancers, which also has the highest mortality rate worldwide. Multiple studies have authenticated that circular RNAs (circRNAs) significantly work on the progression of cancers. circRNA hsa_circ_0030018 was also verified to exert functions on the development of glioma previously. Nevertheless, the biological function of hsa_circ_0030018 in EC has not been well elucidated yet. In the present study, the results displayed the expression of hsa_circ_0030018 was dramatically increased in EC cells. Inhibition of has_circ_0030018 suppressed cell proliferation, migration, and epithelial-mesenchymal transition (EMT) process in EC. Based on molecular mechanism assays, has_circ_0030018 served as a sponge of miR-599. Enabled homolog (ENAH), which exhibited high expression in EC cells, was confirmed to be a downstream target gene of miR-599. Additionally, has_circ_0030018 positively regulated ENAH expression while miR-599 negatively regulated ENAH expression. Finally, by employing rescue assays, ENAH deficiency partially counteracted the promoting function of miR-599 silence on cell proliferation, migration, and EMT process in EC cotransfected with sh- has_circ_0030018#1 cells. In conclusion, hsa_circ_0030018 acted as a sponge of miR-599 to aggravate EC progression by regulating ENAH expression. Therefore, hsa_circ_0030018 might serve as a promising biomarker and therapeutic target for EC.
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Pigment epithelium-derived factor (PEDF) is an oncogene found in various types of cancers. However, how PEDF affects the development of human esophageal squamous cell carcinoma (ESCC) is unknown. This study investigates the role of PEDF in ESCC cell proliferation, migration, and cell cycle both in vitro and in vivo. The PEDF expression was examined in patient tumor samples and ESCC cell lines. Short hairpin RNA technology was used to inhibit the PEDF expression in ESCC EC9706 and KYSE150 cells. In vitro cell proliferation and migration assays were performed. The effects of PEDF on tumor growth and progression were examined in vivo in murine subcutaneous xenograft tumor models. It was found that PEDF was overexpressed in esophageal cancer cells and patient tumor tissues compared to normal control samples. PEDF enhanced cell cycle progression and inhibited cell apoptosis. Knock down of PEDF inhibited esophageal cell proliferation and migration in vitro. Moreover, Inhibition of PEDF significantly reduced tumor growth and tumor size in vivo. These results indicate that PEDF induce tumorigenesis in ESCC and can be a potential therapeutic target for cancer treatment.
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AIMS: Inflammation is considered to play a critical role in the pathogenesis of diabetic retinopathy, and high mobility group box protein 1 (HMGB1) could promote inflammation as an alarmin. We investigated the expression of HMGB1 signalling pathway components in type 2 diabetic rat retinas and in high glucose cultured ARPE-19 cells. METHODS: Retinal expression of HMGB1 and its receptors in type 2 diabetic rats were detected by western blot and immunohistochemistry. ARPE-19 cells were cultured with low glucose, high glucose (with or without anti-HMGB1 antibody) or mannitol (control) for different lengths of time (12, 24, 48, 72 h). Then expression of HMGB1 and its receptors was measured by immunocytochemistry, ELISA or western blot. Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activity and tumour necrosis factor α (TNFα)/vascular endothelial growth factor (VEGF) production in retinas as well as in ARPE-19 cells were detected by ELISA. Furthermore, blood-retinal barrier permeability and ARPE-19 cell viability were measured by Evans-Blue and Cell Counting Kit-8 assay, respectively. RESULTS: HMGB1 signalling pathway components including receptors for HMGB1 as well as NF-κB and TNFα/VEGF were significantly upregulated in type 2 diabetic retinas and in high glucose treated ARPE-19 cells, compared to their respective counterparts. HMGB1 blockage significantly alleviated NF-κB activity and VEGF secretion in ARPE-19 cells cultured with high glucose. In addition, blood-retinal barrier permeability of the diabetic retinas increased, while cell viability of high glucose treated ARPE-19 cells decreased. CONCLUSIONS: Expression of HMGB1 signalling pathway components were increased in diabetic rat retinas and in ARPE-19 cells exposed to high glucose.
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Retinopatia Diabética/metabolismo , Proteína HMGB1/metabolismo , Retina/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais/fisiologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Retinopatia Diabética/patologia , Glucose/farmacologia , Humanos , Masculino , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/metabolismo , Retina/citologia , Epitélio Pigmentado da Retina/citologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
OBJECTIVE: To compare the short-term outcomes in patients with esophageal cancer after subtotal esophagectomy via thoracoscopy in prone position and in left lateral position. METHODS: Between September 2008 and September 2010, thoraco-laparoscopic esophagectomy (TLE) with thoracoscopic mobilization of the esophagus and mediastinal esophagectomy was performed in 41 patients in prone position (group A) and other 41 patients (group B) performed by the same surgeon in left lateral position. RESULTS: Preoperatively, the endoscopic location of the tumor was in the upper third in 5 cases (2 vs. 3), the middle third in 21 cases (12 vs. 9), and the lower third in 56 cases (27 vs. 29). The median operative time was 230 (range 170-310) min in group A and 280 (range 190-380) min in group B (P=0.04). The median intraoperative blood loss was 275 (range 100-320) ml in group A and 360 (range 120-670) ml in group B (P=0.09). The median number of lymph nodes dissected was 8.4 (range 4-23) in group A and 6.9 (range 6-21) in group B (P=0.03). The postoperative complications totaled 6 (14.6%) in group A and 8 (17.1%) in group B (P=0.44). After a median follow-up period of 15.7 (range 2-28) months for group A and 16.3 (range 3-31) months for group B, 19 patients in group A died and 21 patients in group B. CONCLUSIONS: For esophageal cancer under T3N1M0, surgical outcomes are similar between prone thoracoscopic esophageal mobilization and left lateral position. Prone position may be associated with better lymph node dissection.
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Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Toracoscopia/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Decúbito Ventral , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The abnormal function of O(6)-methylguanine-DNA methyltransferase (MGMT) is reported to be associated with the occurrence of various tumors and malignant tumor progression. However, little evidence is available to describe its role in esophageal carcinogenesis. To address this issue, we constructed a stable MGMT-silenced esophageal cancer cell line by RNA interference, and exposed the cells to N-methyl-N-nitro-N-nitrosoguanidine (MNNG) to investigate the role that MGMT plays in toxicity. During this time, we also observed the malignant behavior of cells in vitro and in vivo. In addition, two-dimensional electrophoresis and mass spectrometry were used to detect and confirm the proteins that were differentially expressed in the MGMT-deficient and MGMT-proficient cells, which might be responsible for the malignant alteration of cells. Results showed that the IC(50) of MGMT-deficient and MGMT-proficient cells exposed to MNNG was 30 µM and 65 µM, respectively, and MGMT-deficient cells had more aggressive motility and invasive abilities compared with MGMT-proficient cells. Nineteen differentially expressed proteins were detected between the MGMT-deficient and MGMT-proficient cells, 14 of which were identified, including the membrane-cytoskeleton linker protein, Ezrin, which was confirmed by both mass spectrometry and western blot analysis. The correlation between MGMT, Ezrin expression, and the malignant behavior of one normal epithelial esophageal cell line and seven esophageal cancer lines is discussed. In conclusion, loss of MGMT expression leads EC109 esophageal cancer cells to have increased malignant behavior, which may correlate with its high Ezrin protein expression.
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Proteínas do Citoesqueleto/metabolismo , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , O(6)-Metilguanina-DNA Metiltransferase/deficiência , Animais , Western Blotting , Células CHO , Adesão Celular , Movimento Celular , Proliferação de Células , Cricetinae , Eletroforese em Gel Bidimensional , Esôfago/metabolismo , Esôfago/patologia , Imunofluorescência , Guanina/análogos & derivados , Guanina/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação/genética , O(6)-Metilguanina-DNA Metiltransferase/antagonistas & inibidores , O(6)-Metilguanina-DNA Metiltransferase/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , TransfecçãoRESUMO
AIMS: The standardized extract from the leaves of Ginkgo biloba (EGb761) is applied as a phyto-pharmacon in therapy of diverse cardiovascular disorders. However, the effects of EGb761 on bone-marrow mesenchymal stem cells (BMSCs) transplanted into the ischemic myocardium currently remain uncertain. In this study, the dosage-effects of EGb761 on BMSC survival in vitro and in vivo were investigated. MAIN METHODS: The ischemic microenvironment of rat BMSCs was simulated by hypoxia/serum deprivation (SD) and the rat myocardial infarction model was established. The rat BMSCs were cultured under hypoxia/SD or transplanted into the animal ischemic heart. The BMSC apoptosis was determined by FACS and TUNEL assay. Each apoptotic signal molecule's activity was assayed by immunoblot. KEY FINDINGS: EGb761 showed a biphasic effect on the hypoxia/SD-induced BMSC apoptosis. Low concentration of EGb761 (10-100µg/ml) aggravated hypoxia/SD-induced apoptosis via Akt inactivation and an enhancement of caspase-9 and caspase-3 expressions, whereas high concentration of EGb761 (500-2000µg/ml) significantly prevented hypoxia/SD-induced BMSC apoptosis via the activated Akt and the inactivated caspase-9 and caspase-3. The animal study also indicated that the apoptotic index (AI) in the high concentration of EGb761 group was significantly lower than the low concentration of EGb761 group. SIGNIFICANCE: The biphasic effect of EGb761 is closely related to the PI3K-Akt and caspase-9 signaling pathways. The therapeutic concentration of EGb761 may be one of the vital factors determining the specific action of EGb761 on cell apoptosis. It is of significant clinical implication to investigate the mechanisms of the biphasic effect of EGb761.