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1.
J Cardiothorac Surg ; 18(1): 359, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38098070

RESUMO

BACKGROUND: Multiple rib fractures can lead to flail chest with up to 35% mortality rate due to severe pulmonary complications. Current treatments of flail chest remain controversial. Studies have shown that surgical treatments can improve outcomes and reduce mortality, comparing to non-operative treatments. Current surgical fixation methods focus on stabilization of ribs on the outward facing side, and they require division of intercostal muscles. Damages to surrounding nerves and vessels may lead to chronic pain. This study tests a novel interior fixation method that minimizes neurovascular injuries. METHODS: Twelve healthy canines were divided in two surgical operation groups for exterior and interior fixation using titanium metal plates. Osteotomy with oblique fractures was prepared under general anesthesia. Exterior fixation was performed in open surgery. Interior fixation was minimally invasive using custom made tools including a flexible shaft extension screwdriver, solid plate stand, guiding wire loop and metal plates with threaded holes. RESULTS: Respiratory and cardiovascular functions (RR, PO2, PCO2, SpO2, and HR) together with body temperature were measured before anesthesia and within 48 h after surgery. The difference in measurements was not statistically significant between the two groups before surgery with P values greater than 0.05. However, the interior group canines had better RR and PO2 values starting from the 24th hour, and better PCO2, SpO2, and HR values starting from the 48th hour. It took longer operation time to complete the minimally invasive interior fixation surgery (P value less than 0.001), but the total blood loss was less than the exterior fixation group (P value less than 0.001). Results also showed that interior group canines suffered less pain, and they had quicker recovery in gastrointestinal and physical mobility. CONCLUSIONS: The investigative interior fixation method was safe and effective in rib stabilization on a canine rib fracture model, comparing to the exterior fixation method. The interior fixation was minimally invasive, with less damages to tissues and nerves surrounding the ribs, leading to better postoperative outcomes.


Assuntos
Experimentação Animal , Tórax Fundido , Fraturas das Costelas , Animais , Cães , Tórax Fundido/cirurgia , Fixação Interna de Fraturas/métodos , Fraturas das Costelas/cirurgia , Costelas
3.
Altern Ther Health Med ; 29(5): 396-399, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37171949

RESUMO

Background: To investigate the value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the diagnosis of lung nodules related enlarged mediastinal lymph nodes (MLNs). Methods: Clinical data of 108 patients with lung nodules related enlarged MLNs who underwent EBUS-TBNA in our single center were retrospectively analyzed from January 2020 to December 2021. The sensitivity and specificity of EBUS-TBNA in malignancy diagnosis were evaluated. Associations between ultrasonic image measurement indexes and malignancy diagnosis were explored. The receiver operating characteristic (ROC) curve of these indexes, the area under curve (AUC), and the corresponding cut-off values were calculated to predict malignant MLNs. Results: Sensitivity, specificity, and accuracy of EBUS-TBNA in the diagnosis of lung nodules related malignant MLNs were 89.47%, 100%, and 92.59%, respectively. There were significantly higher proportions of malignant MLNs with clear boundary, short diameter ≥1 cm, lower long to short diameter ratio, abundant flow of blood, and destructed medulla than that of benign ones (P < .05). According to ROC curve analysis, the cut-off value of short diameters for predicting malignant MLNs was 1.085 cm, and the AUC was 0.796 (95% confidence interval: 0.724-0.868, P < .001). Corresponding sensitivity and specificity were 61.36% and 80.00%, respectively. The cut-off value of the long to short diameter ratio for predicting malignancy was 1.405, and the AUC was 0.697 (95% confidence interval: 0.609-0.790, P < .001). Corresponding sensitivity and specificity were 70.00% and 71.97%, respectively. Conclusion: EBUS-TBNA has a satisfactory accuracy of lung nodules related MLNs diagnosis. Short diameters and long to short diameter ratio of lung nodules related MLNs in ultrasonic image may contribute to the prediction of malignant lymph nodes.


Assuntos
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Estudos Retrospectivos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Pulmão
4.
Biochem Genet ; 60(5): 1585-1600, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35064360

RESUMO

In the previous studies, circular RNA (circRNA) has been shown to be closely related to the occurrence and development of various cancers. However, the role and mechanism of circ-ATIC in the progression of esophageal squamous cell carcinoma (ESCC) is not yet clear. Quantitative real-time PCR was used to detect the expression levels of circ-ATIC, microRNA (miR)-326 and inhibitor of DNA binding 1 (ID1) in tissues (n = 50) and cells. Cell counting kit 8 assay, colony formation assay, flow cytometry, wound-healing assay and transwell assay were performed to measure the proliferation, apoptosis, migration, and invasion of cells. In addition, the oxidative stress of cells was evaluated by detecting the productions of superoxide dismutase and malondialdehyde. Animal studies were implied to explore the role of circ-ATIC in ESCC tumor growth. The relationship between circ-ATIC and miR-326 or ID1 was determined by dual-luciferase reporter assay and RNA immunoprecipitation assay. Additionally, the protein expression of ID1 was examined by western blot assay. Circ-ATIC was found to be upregulated in ESCC tissues and cells. Silenced circ-ATIC suppressed the proliferation, migration, invasion, promoted the apoptosis and oxidative stress of ESCC cells. The tumor growth of ESCC also was inhibited by circ-ATIC knockdown. Furthermore, we found that circ-ATIC could sponge miR-326, and miR-326 could target ID1. The rescue experiments revealed that miR-326 inhibitor could reverse the negative regulation of circ-ATIC silencing on ESCC progression, and ID1 overexpression also inverted the inhibitory effect of miR-326 on ESCC progression. In addition, we confirmed that the expression of ID1 was positively regulated by circ-ATIC. Our study showed that circ-ATIC facilitated the progression of ESCC by regulating the miR-326/ID1 axis, indicating that circ-ATIC might be a target for ESCC treatment.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , MicroRNAs , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo
5.
Mamm Genome ; 32(6): 508-516, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34586488

RESUMO

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Tyrosine kinase inhibitors (TKIs) are currently the most effective chemotherapy for NSCLC. However, most cancer patients develop TKI resistance at tumor relapse stage. We firstly measured the expression change of miR-519d-3p in TKI resistance NSCLC cells. We then ectopically expressed miR-519-3p in TKI resistant cells to study its functional impact on cell proliferation, migration, invasion and cell sensitivity to gefitinib. The downstream target of miR-519-3p was identified by bioinformatics and validated in luciferase reporter assay and western blotting analysis. We also studied the reversing effect of the candidate target in NSCLC cells expressing miR-519d-3p. Lastly, we compared the miR-519d-3p level in NSCLC patients with good or poor response to gefitinib. miR-519d-3p level was downregulated in TKI resistant NSCLC cells. The restoration of miR-519d-3p in these NSCLC cells inhibited cell proliferation, invasion and migration; enhanced cell sensitivity to gefitinib. EPAS1 was identified and validated as downstream target of miR-519d-3p. Co-expressing EPAS1 antagonized the inhibitory effect of miR-519d-3p on NSCLC cells. MiR-519d-3p was downregulated in NSCLC patients with poor response to gefitinib. Targeting miR-519d-3p/EPAS1 axis may provide alternative treatment for TKI-resistant NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
6.
Clin Cancer Res ; 27(8): 2255-2265, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33627492

RESUMO

PURPOSE: Nodule evaluation is challenging and critical to diagnose multiple pulmonary nodules (MPNs). We aimed to develop and validate a machine learning-based model to estimate the malignant probability of MPNs to guide decision-making. EXPERIMENTAL DESIGN: A boosted ensemble algorithm (XGBoost) was used to predict malignancy using the clinicoradiologic variables of 1,739 nodules from 520 patients with MPNs at a Chinese center. The model (PKU-M model) was trained using 10-fold cross-validation in which hyperparameters were selected and fine-tuned. The model was validated and compared with solitary pulmonary nodule (SPN) models, clinicians, and a computer-aided diagnosis (CADx) system in an independent transnational cohort and a prospective multicentric cohort. RESULTS: The PKU-M model showed excellent discrimination [area under the curve; AUC (95% confidence interval (95% CI)), 0.909 (0.854-0.946)] and calibration (Brier score, 0.122) in the development cohort. External validation (583 nodules) revealed that the AUC of the PKU-M model was 0.890 (0.859-0.916), higher than those of the Brock model [0.806 (0.771-0.838)], PKU model [0.780 (0.743-0.817)], Mayo model [0.739 (0.697-0.776)], and VA model [0.682 (0.640-0.722)]. Prospective comparison (200 nodules) showed that the AUC of the PKU-M model [0.871 (0.815-0.915)] was higher than that of surgeons [0.790 (0.711-0.852), 0.741 (0.662-0.804), and 0.727 (0.650-0.788)], radiologist [0.748 (0.671-0.814)], and the CADx system [0.757 (0.682-0.818)]. Furthermore, the model outperformed the clinicians with an increase of 14.3% in sensitivity and 7.8% in specificity. CONCLUSIONS: After its development using machine learning algorithms, validation using transnational multicentric cohorts, and prospective comparison with clinicians and the CADx system, this novel prediction model for MPNs presented solid performance as a convenient reference to help decision-making.


Assuntos
Tomada de Decisão Clínica/métodos , Neoplasias Pulmonares/epidemiologia , Pulmão/diagnóstico por imagem , Aprendizado de Máquina , Nódulos Pulmonares Múltiplos/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Nódulos Pulmonares Múltiplos/diagnóstico , Nódulos Pulmonares Múltiplos/terapia , Estudos Prospectivos , Curva ROC , Medição de Risco/métodos , Tomografia Computadorizada por Raios X , Adulto Jovem
7.
Strahlenther Onkol ; 197(2): 141-149, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32681351

RESUMO

BACKGROUND: Non-small-cell lung cancer (NSCLC) is a major cause of cancer-related death globally. Endothelial PAS domain-containing protein 1 (EPAS1) is a homolog of the hypoxia-inducible factor 1α and has been reported to confer tyrosine kinase inhibitor (TKI) resistance in NSCLC, but its role in peritoneal carcinomatosis of NSCLC is unknown. METHODS: PC14HM, a high metastatic potential subline of NSCLC cell line PC14, was derived. Stable shRNA knockdown of EPAS1 was then established in PC14HM cells and subjected to assessment regarding the effects on proliferation and viability, xenograft tumor growth, metastatic potential, mesothelial-mesenchymal transition (MMT)-related characteristics and peritoneal carcinomatosis in a mouse model. RESULTS: EPAS1 expression was elevated in PC14HM cells. Knockdown of EPAS1 inhibited the proliferation and viability of PC14HM cells in vitro and suppressed tumorigenesis in vivo. In addition, the metastatic features and in vitro productions of MMT-inducing factors in PC14HM cells was also associated with EPAS1. More importantly, knockdown of EPAS1 drastically suppressed peritoneal carcinomatosis of PC14HM cells in vivo. CONCLUSION: EPAS1 promotes peritoneal carcinomatosis of NSCLC through enhancement of MMT and could therefore serve as a prognostic marker or a therapeutic target in treating NSCLC, particularly in patients with peritoneal carcinomatosis.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Transição Epitelial-Mesenquimal , Neoplasias Pulmonares/patologia , Invasividade Neoplásica/genética , Neoplasias Peritoneais/secundário , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Neoplasias Pulmonares/genética , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica/patologia , Neoplasias Peritoneais/patologia , Regulação para Cima
8.
Cancer Control ; 25(1): 1073274818769849, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29651883

RESUMO

BACKGROUND: Long noncoding RNAs (lncRNAs) are a new class of cancer regulators. Here, we aimed to investigate the diagnostic and therapeutic values of an lncRNA, differentiation antagonizing noncoding RNA (DANCR), in lung cancer. METHODS: Real-time polymerase chain reaction was used to compare DANCR levels in normal and cancerous lung tissues as well as lung cancer cells. Lentiviral transduction was used to induce DANCR overexpression or silencing in vitro, followed by monitoring cell proliferation, colony formation, and changes in microRNA-216a (miR-216a) expression. DANCR-specific small hairpin RNA transduction was used to establish cells with stable DANCR knockdown, and silenced cells were used to initiate lung tumor xenografts, followed by monitoring tumor growth. RESULTS: DANCR upregulation was seen in lung cancer, particularly in high-grade lung cancer tissues and aggressive cancer cells. Ectopic DANCR expression induced lung cancer cell proliferation and colony formation, whereas DANCR silencing induced opposing effects. The miR-216a level in cancer cells was negatively correlated with DANCR expression. The DANCR knockdown reduced the growth of tumor xenografts in vivo. CONCLUSION: DANCR upregulation is a potential indicator of aggressive lung cancer. Silencing of DANCR has great potential as a potent therapeutic strategy in lung cancer.


Assuntos
Neoplasias Pulmonares/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , MicroRNAs/biossíntese , MicroRNAs/metabolismo , Gradação de Tumores , RNA Longo não Codificante/metabolismo , Transfecção , Regulação para Cima
9.
Cell Biochem Funct ; 36(1): 27-33, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29314203

RESUMO

Oesophageal cancer (OC) is one of the most fatal malignancies in the world, and chemoresistance restricts the therapeutic outcome of OC. Long noncoding RNA (lncRNA) was reported to play roles in multiple cancer types. Yet, the function of lncRNA in chemoresistance of OC has not been reported. A lncRNA gene, PCAT-1, showed higher expression in OC tissues, especially higher in secondary OC compared with normal mucosa tissues. Overexpression of PCAT-1 increased the proliferation rate and growth of OC cells. Inhibition of PCAT-1 decreased proliferation and growth of OC cells, and increased cisplatin chemosensitivity. In a mouse OC xenograft model, PCAT-1 inhibition repressed OC growth in vivo. Therefore, PCAT-1 may potentially serve as a therapeutic target for treating OC. PCAT-1 promotes development of OC and represses the chemoresistance of OC to cisplatin, and silencing of PCAT-1 may be a therapeutic strategy for treating OC.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/patologia , RNA Longo não Codificante/genética , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Esofágicas/genética , Humanos , Masculino , Camundongos , Camundongos Nus , RNA Longo não Codificante/metabolismo , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Tumour Biol ; 39(5): 1010428317706215, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28488541

RESUMO

Non-small cell lung cancer accounts for 85% of all types of lung cancer and is the leading cause of worldwide cancer-associated mortalities. MiR-124 is epigenetically silenced in various types of cancer and plays important roles in tumor development and progression. MiR-124 was also significantly downregulated in non-small cell lung cancer patients. Glycolysis has been considered as a feature of cancer cells; hypoxia-inducible factor 1-alpha/beta and Akt are key enzymes in the regulation of glycolysis and energy metabolism in cancer cells. However, the role of miR-124 in non-small cell lung cancer cell proliferation, glycolysis, and energy metabolism remains unknown. In this research, cell proliferation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; furthermore, glucose consumption and lactic acid production were assessed; adenosine triphosphate content and NAD+/NADH were also detected. These tests were conducted using the normal non-small cell lung cancer cell line A549, which was transfected variedly with miR-mimics, miR-124 mimics, miR-124 inhibitor, pc-DNA3.1(+)-AKT1, and pc-DNA3.1(+)-AKT2 plasmid. Here, we show that miR-124 overexpression directly decreased cell growth, glucose consumption, lactate production, and energy metabolism. MiR-124 also negatively regulates glycolysis rate-limiting enzymes, glucose transporter 1 and hexokinase II. Our results also showed that miR-124 negatively regulates AKT1 and AKT2 but no regulatory effect on hypoxia-inducible factor 1-alpha/beta. Overexpression of AKT reverses the inhibitory effect of miR-124 on cell proliferation and glycolytic metabolism in non-small cell lung cancer. AKT inhibition blocks miR-124 silencing-induced AKT1/2, glucose transporter 1, hexokinase II activation, cell proliferation, and glycolytic or energy metabolism changes. In summary, this study demonstrated that miR-124 is able to inhibit proliferation, glycolysis, and energy metabolism, potentially by targeting AKT1/2-glucose transporter 1/hexokinase II in non-small cell lung cancer cells.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Transportador de Glucose Tipo 1/genética , Hexoquinase/genética , MicroRNAs/genética , Proteína Oncogênica v-akt/genética , Células A549 , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/genética , Metabolismo Energético/genética , Regulação Neoplásica da Expressão Gênica , Glicólise/genética , Humanos
11.
DNA Cell Biol ; 35(11): 715-721, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27494742

RESUMO

Lung cancer is one of the most malignant cancers with a high metastatic potential. The purpose of this study was to study the role and the underlying mechanism of miR-214 in lung cancer progression. The expression of miR-214 in normal lung and lung cancer tissue was analyzed by quantitative real-time PCR analysis. Furthermore, H1299 cells were infected with miR-214 lentivirus, and the effect of infection on cell viability and migration was analyzed. Carboxypeptidase-D (CPD), as a potential target of miR-214, was characterized in either normal lung or lung cancer tissues. The interaction of CPD expression with the tumor suppressing effect of miR-214 was characterized. We demonstrated that low miR-214 expression is a hallmark of lung cancer, especially high-grade and metastatic cancer. In vitro studies in H1299 cells confirmed that low miR-214 expression is associated with enhanced proliferation and migratory abilities. Similarly, CPD overexpression coincides with high-grade lung cancer and the CPD overexpression could reverse the inhibitory effects of miR-214. miR-214 is a tumor suppressor in lung cancer. miR-214 inhibits lung cancer progression by targeting CPD. The miR-214-CPD axis may be a therapeutic axis for lung cancer patients.


Assuntos
Carboxipeptidases/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Carboxipeptidases/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Genes Supressores de Tumor , Humanos
12.
J Physiol Biochem ; 72(2): 337-43, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27083571

RESUMO

miR-148b has been found to be aberrantly expressed in various tumor types. It has recently been reported to be involved in regulating radioresistance in non-small cell lung cancer (NSCLC) cells. However, its expression level and association with radiosensitivity in human patient samples have not been investigated. Real-time PCR was used to evaluate the expression levels of miR-148b. Χ (2) test was performed to analyze the association between miR-148b expression levels and clinicopathological factors or radiosensitivity. Kaplan-Meier survival curve was constructed to estimate the overall survival (OS), and the differences in survival were compared using the log-rank test. Cox regression analysis was conducted to determine the prognostic value of miR-148b. The relative level of miR-148b was significantly decreased in NSCLC tissues compared with matched non-cancerous tissues (P < 0.0001), and it was higher in tissues of patients who are good responders compared to those who are poor responders to radiotherapy (P < 0.0001). Lower expression of miR-148b was positively associated with high tumor stage (P = 0.0407) and radioresistance (P = 0.0002), and it predicted poor survival in patients with (P = 0.0129) or without (P = 0.0094) radiotherapy treatment. miR-148b was an independent prognostic factor for NSCLC as demonstrated by Cox proportional hazards risk analysis. miR-148b may serve as a prognostic biomarker of poor survival and a novel predictor of response to radiotherapy treatment in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Neoplasias Pulmonares/radioterapia , Pulmão/efeitos da radiação , MicroRNAs/metabolismo , RNA Neoplásico/metabolismo , Biomarcadores/metabolismo , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sobrevida
13.
Cytogenet Genome Res ; 146(1): 1-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26184032

RESUMO

Lung cancer, especially non-small cell lung cancer (NSCLC), is the major cause of cancer death worldwide. Mutations in epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-Met), both of which are receptor tyrosine kinases, have been identified in a considerable percentage of NSCLC patients. EGFR and c-Met share the same downstream pathways and cooperate not only in promoting metastasis but also in conferring resistance to tyrosine kinase inhibitor (TKI) therapies in NSCLC. MicroRNAs (miRNAs) are a family of small non-coding RNAs, usually 21-25 nucleotides long, and are critical in regulating gene expression. Abnormal miRNA expression has been implicated in the initiation and progression in many forms of cancers, including lung cancer. In this study, we found that miR-200a is downregulated in NSCLC cells, where it directly targets the 3'-UTR of both EGFR and c-Met mRNA. Overexpression of miR-200a in NSCLC cells significantly downregulates both EGFR and c-Met levels and severely inhibits cell migration and invasion. Moreover, in NSCLC cell lines that are resistant to gefitinib, a drug often used in TKI therapies to treat NSCLC, miR-200a expression is able to render the cells much more sensitive to the drug treatment.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , MicroRNAs/fisiologia , Proteínas Proto-Oncogênicas c-met/genética , Quinazolinas/farmacologia , Regiões 3' não Traduzidas , Sequência de Bases , Sítios de Ligação , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/metabolismo , Gefitinibe , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Invasividade Neoplásica , Proteínas Proto-Oncogênicas c-met/metabolismo , Interferência de RNA
14.
Cancer Biol Ther ; 16(4): 549-57, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25831463

RESUMO

Mutations in epidermal growth factor receptor (EGFR) rendering it constitutively active is one of the major causes for metastatic non-small-cell lung cancer (NSCLC), and EGFR-targeted therapies utilizing tyrosine kinase inhibitors (TKIs) are often used clinically as the first-line treatment. But approximately half of NSCLC patients develop resistance to these therapies, where the MET proto-oncogene is amplified by EGFR through the hypoxia-inducible factor (HIF)-1α. Here we report that endothelial PAS domain-containing protein 1 (EPAS1), with 48% sequence identity to HIF-1α, specifically binds to TKI-resistant T790M EGFR, but not to wild-type EGFR, in NSCLC cell lines. Expression of EPAS1 enhances amplification of MET when simultaneously expressed with T790M EGFR but not with wild-type EGFR, and this enhancement is independent of ligand binding domain of EGFR. MET amplification requires EPAS1, since EPAS1 knock-down reduced MET levels. When NSCLC cells expressing T790M EGFR were treated with TKIs, reduced EPAS1 levels significantly enhanced the drug effect, whereas over-expression of EPAS1 increased the drug resistant effect. This EPAS1-dependent TKI-resistance was abolished by knocking-down MET, suggesting that EPAS1 does not cause TKI-resistance itself but functions to bridge EGFR and MET interactions. Our findings suggest that EPAS1 is a key factor in the EGFR-MET crosstalk in conferring TKI-resistance in NSCLC cases, and could be used as a potential therapeutic target in TKI-resistant NSCLC patients.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Amplificação de Genes/genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Pulmonares/tratamento farmacológico , Proto-Oncogene Mas
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