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BACKGROUND: Patients with DNA mismatch repair-proficient/microsatellite stable (pMMR/MSS) colorectal cancer (CRC), which accounts for 85% of all CRC cases, display a poor respond to immune checkpoint inhibitors (i.e., anti-PD-1 antibodies). pMMR/MSS CRC patients with locally advanced cancers need effective combined therapies. METHODS: In this pilot study, we administered six preoperative doses of each 2-week cycle of the anti-PD-1 antibody sintilimab (at a fixed dose of 200 mg), oxaliplatin, and 5-FU/CF (mFOLFOX6) combined with five doses of bevacizumab (the number of doses was reduced to prevent surgical delays) to patients with cT4NxM0 colon or upper rectal cancers. And radical surgery was performed approximately 2 weeks after the last dose of neoadjuvant therapy. The primary endpoint was a pathologic complete response (pCR). We also evaluated major pathologic response (MPR, ≤10% residual viable tumor), radiological and pathological regression, safety, and tumor mutation burden (TMB), and tumor microenvironment (TME) characteristics. RESULTS: By the cutoff date (September 2023), 22 patients with cT4NxM0 pMMR/MSS colon or upper rectal cancers were enrolled and the median follow-up was 24.7 months (IQR: 21.1-26.1). All patients underwent R0 surgical resection without treatment-related surgical delays. pCR occurred in 12 of 22 resected tumors (54.5%) and MPR occurred in 18 of 22 (81.8%) patients. At the cutoff date, all patients were alive, and 21/22 were recurrence-free. Treatment-related adverse events of grade 3 or higher occurred in of 2/22 (9.1%) patients. Among the pCR tumors, two were found to harbor POLE mutations. The degree of pathological regression was significantly greater than that of radiological regression (p = 1.35 × 10-8). The number of CD3+/CD4+ cells in the tumor and stroma in pretreated biopsied tissues was markedly lower in pCR tumors than in non-pCR tumors (p = 0.038 and p = 0.015, respectively). CONCLUSIONS: Neoadjuvant sintilimab combined with bevacizumab and mFOLFOX6 was associated with few side effects, did not delay surgery, and led to pCR and non-pCR in 54.5% and 81.8% of the cases, respectively. Downregulation of CD3/CD4 expression in the tumor and stroma is related to pCR. However, the molecular mechanisms underlying PD-1 blockade-enhanced targeted chemotherapy require further investigation.
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Protocolos de Quimioterapia Combinada Antineoplásica , Bevacizumab , Neoplasias Colorrectales , Fluorouracilo , Inhibidores de Puntos de Control Inmunológico , Humanos , Masculino , Femenino , Persona de Mediana Edad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Anciano , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Fluorouracilo/uso terapéutico , Fluorouracilo/administración & dosificación , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Proyectos Piloto , Bevacizumab/uso terapéutico , Bevacizumab/administración & dosificación , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Leucovorina/uso terapéutico , Leucovorina/administración & dosificación , Reparación de la Incompatibilidad de ADN , Adulto , Inestabilidad de Microsatélites , Oxaliplatino/uso terapéutico , Oxaliplatino/administración & dosificación , Terapia Neoadyuvante/métodos , Microambiente Tumoral/inmunología , Compuestos Organoplatinos/uso terapéutico , Compuestos Organoplatinos/administración & dosificación , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Resultado del TratamientoRESUMEN
Clinical treatment for osteosarcoma (OS) is still lacking effective means, and no significant progress in OS treatment have been made in recent years. Single chemotherapy has serious side effects and can produce drug resistance easily, resulting poor therapeutic effect. As a modern and non-invasive treatment form, photodynamic therapy (PDT) is widely used to treat diverse cancers. Chemotherapy in combination with PDT is a particularly efficient antitumor method that could overcome the defects of monotherapies. Since mitochondria is a key subcellular organelle involved in cell apoptosis regulation, targeting tumor cells mitochondria for drug delivery has become an important entry point for anti-tumor therapy. Herein, we rationally designed a core-shell structured biomimetic nanoplatform, i.e., D@SLNP@OSM-IR780, to achieve tumor homologous targeting and mitochondria targeted drug release for chemotherapy combined with PDT against OS. Upon 808 nm laser irradiation, D@SLNP@OSM-IR780 exhibited excellent photo-cytotoxicity in vitro. The excellent targeting effect of D@SLNP@OSM-IR780 in tumor tissues produced a tumor inhibition rate of 98.9% in vivo. We further indicated that synergistic chemo-photodynamic effect induced by D@SLNP@OSM-IR780 could activate mitochondria-mediated apoptosis pathway, along with host immune response and potential photothermal effect. On the whole, D@SLNP@OSM-IR780 is revealed to be a promising platform for OS targeted combination therapeutics.
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Neoplasias Óseas , Nanopartículas , Osteosarcoma , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Biomimética , Nanopartículas/uso terapéutico , Osteosarcoma/tratamiento farmacológico , Neoplasias Óseas/tratamiento farmacológico , Mitocondrias , Línea Celular TumoralRESUMEN
Indolent T-cell lymphoma is a rare disease. Here we presented a 53-year-old male patient initially diagnosed as ulcerative colitis in 2000 that finally developed into extensive indolent T-cell lymphoma in 2022. We also described the differences between indolent T-cell lymphoma and inflammatory bowel disease, and the possible disease progression into lymphoma after biological therapy.
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Colitis Ulcerosa , Enfermedades Inflamatorias del Intestino , Linfoma de Células T , Linfoma , Masculino , Humanos , Persona de Mediana Edad , Colitis Ulcerosa/complicaciones , Colitis Ulcerosa/patología , Linfoma de Células T/complicaciones , Linfoma de Células T/diagnóstico por imagen , Linfoma de Células T/patología , Enfermedades Inflamatorias del Intestino/patología , Progresión de la EnfermedadRESUMEN
BACKGROUND AND AIMS: Partial pancreatectomy, commonly used for chronic pancreatitis, or pancreatic lesions, has diverse impacts on endocrine and metabolism system. The study aims to determine the global prevalence of new-onset, worsening, and resolution of diabetes following partial pancreatectomy. METHODS: The authors searched PubMed, Embase, Web of Science, and Cochrane Library from inception to October, 2023. DerSimonian-Laird random-effects model with Logit transformation was used. Sensitivity analysis, meta-regression, and subgroup analysis were employed to investigate determinants of the prevalence of new-onset diabetes. RESULTS: A total of 82 studies involving 13 257 patients were included. The overall prevalence of new-onset diabetes after partial pancreatectomy was 17.1%. Univariate meta-regression indicated that study size was the cause of heterogeneity. Multivariable analysis suggested that income of country or area had the highest predictor importance (49.7%). For subgroup analysis, the prevalence of new-onset diabetes varied from 7.6% (France, 95% CI: 4.3-13.0) to 38.0% (UK, 95% CI: 28.2-48.8, P <0.01) across different countries. Patients with surgical indications for chronic pancreatitis exhibited a higher prevalence (30.7%, 95% CI: 21.8-41.3) than those with pancreatic lesions (16.4%, 95% CI: 14.3-18.7, P <0.01). The type of surgical procedure also influenced the prevalence, with distal pancreatectomy having the highest prevalence (23.7%, 95% CI: 22.2-25.3, P <0.01). Moreover, the prevalence of worsening and resolution of preoperative diabetes was 41.1 and 25.8%, respectively. CONCLUSIONS: Postoperative diabetes has a relatively high prevalence in patients undergoing partial pancreatectomy, which calls for attention and dedicated action from primary care physicians, specialists, and health policy makers alike.
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Diabetes Mellitus , Pancreatectomía , Humanos , Pancreatectomía/efectos adversos , Diabetes Mellitus/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Prevalencia , Pancreatitis Crónica/cirugía , Pancreatitis Crónica/epidemiología , Salud GlobalRESUMEN
For colorectal cancer (CRC), surgical resection remains essential for achieving good prognoses. Unfortunately, numerous patients with locally advanced CRC and metastatic CRC failed to meet surgical indications or achieve pathological complete response after surgery. Perioperative therapy has been proven to effectively lower tumor staging and reduce recurrence and metastasis. Immune checkpoint inhibitors (ICIs) have shown unprecedented prolongation of survival time and satisfactory safety in patients with high microsatellite instability/deficient mismatch repair (MSI-H/dMMR), while the therapeutic effect obtained by patients with mismatch repair-proficient or microsatellite stable (pMMR/MSS) was considered minimal. However, recent studies found that certain CRC patients with dMMR/MSI-H presented intrinsic or acquired immune resistance, and pMMR/MSS CRC patients can also achieve better efficacy. Therefore, more predictors are required for screening patients with potential clinical benefits. Since the discovery of synergistic effects between immunotherapy, chemotherapy, and radiotherapy, different immunotherapy-based therapies have been applied to the perioperative therapy of CRC in an increasing number of research. This review comprehensively summarized the past and current progress of different combinations of immunotherapy in perioperative clinical trials for CRC, focusing on the efficacy and safety, and points out the direction for future development.
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Neoplasias Encefálicas , Neoplasias Colorrectales , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia , Neoplasias Colorrectales/terapia , Inestabilidad de MicrosatélitesRESUMEN
Diabetes mellitus (DM) is a systemic metabolic disease with high mortality and morbidity. Extracellular vesicles (EVs) have emerged as a novel class of signaling molecules, biomarkers and therapeutic agents. EVs-mediated intercellular and interorgan crosstalk of pancreatic islets plays a crucial role in the regulation of insulin secretion of ß-cells and insulin action in peripheral insulin target tissues, maintaining glucose homeostasis under physiological conditions, and it's also involved in pathological changes including autoimmune response, insulin resistance and ß-cell failure associated with DM. In addition, EVs may serve as biomarkers and therapeutic agents that respectively reflect the status and improve function and viability of pancreatic islets. In this review, we provide an overview of EVs, discuss EVs-mediated intercellular and interorgan crosstalk of pancreatic islet under physiological and diabetic conditions, and summarize the emerging applications of EVs in the diagnosis and treatment of DM. A better understanding of EVs-mediated intercellular and interorgan communication of pancreatic islets will broaden and enrich our knowledge of physiological homeostasis maintenance as well as the development, diagnosis and treatment of DM.
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Diabetes Mellitus , Vesículas Extracelulares , Islotes Pancreáticos , Humanos , Fenómenos Fisiológicos Celulares , InsulinaRESUMEN
T-cell lymphoma (TCL) is a highly heterogeneous group of invasive non-Hodgkin lymphoma with adverse prognosis and limited treatment options. The relationship between TCL and Exportin-1 (XPO1), a major nuclear export receptor, has not been established yet. We here investigated the prognostic role and therapeutic implication of XPO1 in TCL. We analyzed XPO1 expression in a cohort of 69 TCL tumors and found that XPO1 was over-expressed in 76.8% of TCL and correlated with decreased progression-free survival (PFS) and overall survival (OS). In vitro treatment of TCL cell lines with KPT-8602, the second-generation selective inhibitor of nuclear export (SINE), inhibited XPO1 expression and showed significant anti-proliferative, cell-cycle arrest and pro-apoptotic efficacy. In mechanism, KPT-8602 restored the localization of cytoplasmic FOXO3A, p27, p21, IκBα and PP2A into the nucleus, leading to AKT and NF-κB deactivation. Our data demonstrate for the first time that XPO1 could be an unfavorable prognostic factor for TCL, and provide a rationale for further investigation of the efficacy of KPT-8602 in TCL patients.
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Hidrazinas , Linfoma de Células T , Transporte Activo de Núcleo Celular , Apoptosis , Línea Celular Tumoral , Humanos , Hidrazinas/farmacología , Carioferinas/genética , Carioferinas/metabolismo , Pronóstico , Receptores Citoplasmáticos y Nucleares , Proteína Exportina 1RESUMEN
BACKGROUND: Monomorphic epitheliotropic intestinal T cell lymphoma (MEITL) is a rare extra-nodal T-cell lymphoma that has uniformly aggressive features with a poor prognosis. No standardized treatment protocols have been established. Previous experience has demonstrated favorable outcomes with combination chemotherapy followed by autologous hematopoietic stem cell transplant. However, many patients are unable to tolerate the toxicities. Chidamide is a new histone deacetylase inhibitor that has shown preferential efficacy in mature T-cell lymphoma. CASE SUMMARY: We herein present two cases of MEITL who were both intermediate risk according to enteropathy-associated T cell lymphoma prognostic index. Case one was a 61-year-old man. He complained of upper abdominal pain and intermittent black stool for 2 mo. Imaging examination revealed that the intestinal wall was thickened. He received a partial excision of the small intestine. A chidamide-based combination regimen was given postoperatively. Eleven months later, he presented with recurrence in the bilateral lungs. He passed away 15 mo after his diagnosis. Case two was a 35-year-old woman who complained of abdominal distention for 1 mo. Positron emission tomography/computed tomography demonstrated wall thickening of the small intestine and upper sigmoid colon. Colon perforation and septic shock occurred on the fourth day of her admission. She was treated by sigmoid colostomy. Chidamide-based combination therapy was then provided. She was recurrence-free for 6 mo until lesions were found in the bilateral brain and lived for 17 mo since her diagnosis. Compared to historical data, chidamide seems to improve the prognosis of MEITL slightly. CONCLUSION: MEITL is a type of aggressive lymphoma. Chidamide is a new promising approach for the treatment of MEITL.
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T-cell acute lymphoblastic leukaemia (T-ALL) is an aggressive haematological malignancy that is characterized by a high frequency of induction failure and by early relapse. Many studies have revealed that metadherin (MTDH) is highly expressed in a variety of malignant solid tumours and plays an important role in the occurrence and development of tumours. However, the relationship between the expression of MTDH and T-ALL has not yet been reported, and the regulatory factors of MTDH are still unknown. Our previous studies found that mPGES-1/PGE2 was important for promoting the growth of leukaemia cells. In the present study, we found that MTDH was highly expressed in primary T-ALL cells and in the Jurkat cell line. Our results showed that mPGES-1/PGE2 regulates the expression of MTDH through the EP3/cAMP/PKA-CREB pathway in T-ALL cells. Downregulation of MTDH inhibits the growth of Jurkat cells in vitro and in vivo. Our results suggest that MTDH could be a potential target for the treatment of T-ALL.
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Proteína de Unión a CREB/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Proteínas de la Membrana/biosíntesis , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Prostaglandina-E Sintasas/metabolismo , Proteínas de Unión al ARN/biosíntesis , Subtipo EP3 de Receptores de Prostaglandina E/metabolismo , Línea Celular Tumoral , Células HEK293 , Humanos , Células Jurkat , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Prostaglandina-E Sintasas/biosíntesis , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Transducción de SeñalRESUMEN
Context: Shenmai Injection (SMI) is usually used to treat atherosclerotic coronary heart disease and viral myocarditis in China. However, the effect of SMI on multidrug resistance has not been reported.Objective: To investigate the reversal effect of SMI in adriamycin (ADR) resistant breast cancer cell line (MCF-7/ADR) and explore the related molecular mechanisms.Materials and methods: The effect of SMI (0.25, 0.5, 1 mg/mL) to reverse chemoresistance in MCF-7/ADR cells was elucidated by MTT, HPLC-FLD, DAPI staining, flow cytometric analysis, western blotting. At the same time, in vivo test was conducted to probe into the effect of SMI on reversing ADR resistance, and verapamil (10 µM) was used as a positive control.Results: The results showed that the toxicity of ADR to MCF-7/ADR cells was strengthened significantly after treated with SMI (0.25, 0.5, 1 mg/mL), the IC50 of ADR was decreased 54.4-fold. The intracellular concentrations of ADR were increased 2.2-fold (p < 0.05) and ADR accumulation was enhanced in the nuclei (p < 0.05). SMI could strongly enhance the ADR-induced apoptosis and increase intracellular rhodamine 123 accumulation in MCF-7/ADR cells. Additionally, a combination of ADR and SMI (5 mg/kg) could dramatically reduce the weight and volume of tumour (p < 0.05). Furthermore, the results revealed that SMI might reverse MDR via inhibiting ADR-induced activation of the mitogen-activated protein kinase/nuclear factor (NF)-κB pathway to down-regulated the expression of P-glycoprotein (P-gp).Discussion and conclusions: SMI could potentially be used to treat ADR-resistance. This suggests possibilities for future clinical research.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/farmacología , Medicamentos Herbarios Chinos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , FN-kappa B/metabolismo , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Doxorrubicina/metabolismo , Doxorrubicina/uso terapéutico , Combinación de Medicamentos , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/uso terapéutico , Femenino , Humanos , Células MCF-7 , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Rodamina 123/metabolismo , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
AIMS: Doxorubicin (DOX) is an effective anthracycline anticancer drug. However, the clinical usage of it is limited due to its severe cardiotoxicity side effects. Metformin (Met) is a kind of first-line antihyperglycemic drug which has a potential protective effect on the heartï¼it is often used for oral treatment of type 2 diabetes. In this study, we explored whether Met could attenuate cardiotoxicity induced by DOX. MATERIALS AND METHODS: For the sake of exploring the Met protective effect and mechanism, we established the DOX-induced cardiotoxicity models both in H9C2 cells incubated with 5 µM DOX in vitro and Sprague-Dawley rats treated with 20 mg/kg cumulative dose of DOX. KEY FINDINGS: Met is able to inhibit growth inhibition and apoptosis of H9C2 cells induced by DOX. The heart indexes of rats were examined to evaluate the Met cardiotoxicity protection. Met improved the abnormal indexes, serum markers of cardiac heart injury, echocardiography, electrocardiogram, cardiac pathology, cardiomyocyte apoptosis, and oxidative stress markers induced by DOX. Furthermore, in vivo and in vitro studies demonstrated that Met protected against DOX-induced increasing cleaved caspase-3 and Bax. Met also prevented the downregulation of Bcl-2, activated the AMPK pathway, and inhibited the MAPK pathway. SIGNIFICANCE: Met showed protective effects on DOX-induced cardiotoxicity by reducing oxidative stress and apoptosis, as well as regulating AMPK and MAPK signaling pathways.
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Adenilato Quinasa/metabolismo , Antibióticos Antineoplásicos/toxicidad , Doxorrubicina/toxicidad , Corazón/efectos de los fármacos , Sistema de Señalización de MAP Quinasas , Metformina/farmacología , Animales , Línea Celular , Ratas , Ratas Sprague-DawleyRESUMEN
The anti-inflammatory activity of Quzhou Fructus Aurantii Extract (QFAE) has been reported recently. Thus, present study aims to explore the mechanism of anti-inflammation of QFAE in vitro and in vivo to develop a lung phylactic agent. The anti-inflammatory mechanism of QFAE in RAW 264.7 cells and acute lung injury (ALI) mice model was determined by cytokines analysis, histopathological examination, Western blot assay, immunofluorescence, and immunohistochemistry analysis. The results showed that QFAE restrained mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways in LPS-induced RAW 264.7 cells, whereas AMP-activated protein kinase (AMPK) signaling pathways were activated, as revealed by prominent attenuation of phosphorylation of ERK, JNK, p38, p65, IκBα, RSK and MSK, and overt enhancement of phosphorylation of ACC and AMPKα. The levels of pro-inflammatory cytokines TNF, IL-6, and IL-1ß were suppressed, whereas the level of anti-inflammatory cytokine IL-10 increased after pretreatment with QFAE in vivo and in vitro. Moreover, QFAE prevented mice from LPS-provoked ALI, bases on alleviating neutrophils, and macrophages in bronchoalveolar lavage fluid (BALF) and mitigatingpulmonary histological alters, as well as hematological change. The MAPK and NF-κB signaling pathways in LPS-stimulated ALI mice were dampened by QFAE pretreatment, whereas AMPK signaling pathways were accelerated, as testify by significant restraint of phosphorylation of ERK, JNK, p38, p65, and IκBα, and distinct elevation of phosphorylation of ACC and AMPKα. The remarkable anti-inflammatory effect of QFAE is associated with the suppression of MAPK and NF-κB signaling pathways and the initiation of AMPK signaling pathway.
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Proteínas Quinasas Activadas por AMP/metabolismo , Medicamentos Herbarios Chinos/uso terapéutico , Inflamación/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , FN-kappa B/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Western Blotting , Cromatografía Líquida de Alta Presión , Citocinas/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Ratones , Ratones Endogámicos ICR , Células RAW 264.7/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Previous studies have suggested that microsomal prostaglandin E synthase-1 (mPGES-1) is highly expressed and closely associated with mitogen-activated protein kinase (MAPK) signaling pathways in various types of malignant cells. However, their expression patterns and function with respect to T-cell acute lymphoblastic leukemia (T-ALL) remain largely unknown. The present study investigated whether mPGES-1 served a crucial role in T-ALL and aimed to identify interactions between mPGES-1 and the MAPK signaling pathway in T-ALL. The results indicated that mPGES-1 overexpression in T-ALL jurkat cells was significantly decreased by RNA silencing. Decreasing mPGES-1 on a consistent basis may inhibit cell proliferation, induce apoptosis and arrest the cell cycle in T-ALL jurkat cells. Microarray and western blot analyses revealed that c-Jun N-terminal kinase served a role in the mPGES-1/prostaglandin E2/EP4/MAPK positive feedback loops. In addition, P38 and extracellular signal-regulated kinase 1/2 exhibited negative feedback effects on mPGES-1. In conclusion, the results suggested that cross-talk between mPGES-1 and the MAPK signaling pathway was very complex. Therefore, the combined regulation of mPGES-1 and the MAPK signaling pathway may be developed into a new candidate therapy for T-ALL in the future.
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OBJECTIVE: To investigate the effects of shRNA targeting mPGES-1 on tumorigenicity of human acute leukemia K562 cells in nude mice in vivo and its mechanisms. METHODS: For experiment 3 groups including KD group(expression of mPGES-1 in K562 cells was down-regulated by shRNA), CON (cells without any treatment) and NC group (cells treated with nonspecific-sequence shRNA) were set-up. Western blot was used to test the expression of ß-catenin and cyclinD1 in cells. Then the cells of 3 groups were implanted into BALB/c nude mice subcutaneously to establish murine xenograft model. The growth state of the mice and the size of the xenograft tumor were recorded. HE staining was used to observe the morphology of xenograft tumor. Expressions of ß-catenin and cyclinD1 in xenograft tumor were detected by immunohistochemical staining. RESULTS: In vitro the expression of ß-catenin and cyclinD1 in KD group were lower than the CON group and NC group (P<0.05). In vivo the tumor volume and weight of KD group were significant smaller than the other two groups (P<0.01). HE staining showed that tissues in the KD group were relatively looser in arrangement with smaller cell nucleus and less cytoplasm. The expression of ß-catenin and cyclinD1 in the KD group were remarkable weak as compared with that in CON group and NC group (P<0.05). CONCLUSION: Down-regulating the expression of mPGES-1 by shRNA may significantly inhibit the tumorigenicity of K562 cells in nude mice in vivo and its mechanism may be related with the inhibition of expression of ß-catenin and cyclinD1.