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1.
Artigo em Chinês | MEDLINE | ID: mdl-31495106

RESUMO

Objective: To study the effect of particulate matter 2.5 (PM(2.5)) on oncogene expression in human bronchial epithelial (HBE) cells. Methods: HBE cells were selected as the study subjects, and PM(2.5) treatment group (10 µg/ml and 50 µg/ml) , negative control group and positive control group (10 µmol/L Cr(6+)) were set. CCK8 assay was used to test the IC(50) value of PM(2.5). HBE cells were treated with PM(2.5) for 24 h at 10 µg/ml and 50 µg/ml, additionally, cells were treated with blank as negative control, 10 µmol/L Cr(6+) as a positive control for 24 h. After the treatment, mRNA expression of oncogenes including c-myc, c-fos, k-ras and p53 were detected by fluorescent quantitative RT-PCR, the protein expression of oncogenes were detected with western blot. Results: The IC(50) value of PM(2.5) in HBE cells is 70.12 µg/ml. The qRT-PCR data showed that compared with the control group, the expression level of c-myc gene increased by respectively 500.1%、780.7%、305.3% after exposure to 10、50 µg/ml PM(2.5) and positive control group; c-fos gene increased respectively 34.0%、76.7%、131.3% after exposure to 10、50 µg/ml PM(2.5) and positive control group; k-ras gene increased respectively 50.3%、107.0%、49.7% after exposure to 10、50 µg/ml PM(2.5) and positive control group; p53 gene decreased by 28.3%、28.7%、59.7% after exposure to 10、50 µg/ml PM(2.5) and positive control group. The western blot results showed that compared with the control group, c-myc protein increased respectively 29.7%、77.3% after exposure to 50 µg/ml PM(2.5) and positive control group; c-fos protein increased respectively 200.3%、137.0% after exposure to 50 µg/ml PM(2.5) and positive control group; k-ras protein increased respectively 106.3%、130.3%、116.7% after exposure to 10、50 µg/ml PM(2.5) and positive control group; p53 protein decreased by 43.7%、53.3%、52.1% after exposure to 10、50 µg/ml PM(2.5) and positive control group. Conclusion: PM(2.5) could promote the expression of oncogenes in HBE cells, the carcinogenicity of haze might be related to promotion of oncogenes expression induced by PM(2.5).


Assuntos
Células Epiteliais/efeitos dos fármacos , Oncogenes , Material Particulado/toxicidade , Brônquios/citologia , Células Cultivadas , Humanos , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína Supressora de Tumor p53/genética
2.
Anticancer Res ; 39(9): 4729-4736, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519572

RESUMO

BACKGROUND/AIM: Amphiregulin (AREG) and epiregulin (EREG) mRNA expression levels are predictors of response to anti-EGFR antibody therapy. Left-sided colon cancer is more sensitive to anti-EGFR antibodies than right-sided, although the mechanism is unclear. The aim of this study was to determine the relationship between AREG, EREG mRNA expression levels and tumor location as well as the efficacy of anti-EGFR antibody agents. MATERIALS AND METHODS: Real-time PCR was used to assess AREG and EREG mRNA expression in metastatic colorectal cancer (CRC) samples from 153 patients. RESULTS: Among KRASwt samples, high AREG expression (AREGHigh) was significantly more common in left-sided tumors than in right-sided. Among patients who received anti-EGFR antibody, response rates were significantly higher in AREGHigh than in AREGLow In the left-sided tumor group, overall survival was significantly longer in patients with high EREG levels than with low levels, whereas the right-sided tumor group showed no survival difference between them. CONCLUSION: AREG and EREG mRNA expression levels in left-sided CRC were higher than in right-sided tumors. This may help explain why left-sided CRC is more responsive to anti-EGFR antibodies.


Assuntos
Anfirregulina/genética , Neoplasias Colorretais/genética , Epirregulina/genética , Regulação Neoplásica da Expressão Gênica , RNA Mensageiro/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Imunológicos/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Especificidade de Órgãos/genética , Prognóstico , Proteínas Proto-Oncogênicas p21(ras)/genética
3.
J Cancer Res Clin Oncol ; 145(9): 2273-2283, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31428934

RESUMO

OBJECTIVES: Recent research has classified lung adenocarcinoma patients with KRAS mutation into three subtypes by co-occurring genetic events in TP53 (KP subgroup), STK11/LKB1 (KL subgroup) and CDKN2A/B inactivation plus TTF-1 low expression (KC subgroup). The aim of this study was to identify valuable biomarkers by searching the candidate molecules that contribute to lung adenocarcinoma pathogenesis, especially KC subtype. MATERIALS AND METHODS: We analyzed the publicly available database and identified the candidate REG4 using the E-GEOD-31210 dataset, and then confirmed by TCGA dataset. In addition, an independent cohort of 55 clinical samples was analyzed by quantitative real-time PCR analysis. Functional studies and RNA sequencing were performed after silencing the REG4 expression. RESULTS: REG4, an important regulator of gastro-intestinal carcinogenesis, was highly expressed in KRAS mutant lung adenocarcinoma with low expression of TTF-1 (KC subtype). The results were validated both by gene expression analysis and immunohistochemistry study in an independent 55 clinical samples from Fudan University Shanghai Cancer Center. Further in vitro and in vivo functional assays revealed silencing REG4 expression significantly reduces cancer cell proliferation and tumorigenesis. Moreover, RNA sequencing and GSEA analysis displayed that REG4 knockdown might induce cell cycle arrest by regulating G2/M checkpoint and E2F targets. CONCLUSION: Our results indicate that REG4 plays an important role in KRAS-driven lung cancer pathogenesis and is a novel biomarker of lung adenocarcinoma subtype. Future studies are required to clarify the underlying mechanisms of REG4 in the division and proliferation of KC tumors and its potential therapeutic value.


Assuntos
Adenocarcinoma de Pulmão/diagnóstico , Biomarcadores Tumorais/genética , Transformação Celular Neoplásica/genética , Proteínas de Ligação a DNA/genética , Neoplasias Pulmonares/diagnóstico , Proteínas Associadas a Pancreatite/genética , Proteínas Proto-Oncogênicas p21(ras)/fisiologia , Fatores de Transcrição/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica/patologia , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Mutantes/genética , Proteínas Mutantes/fisiologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Fatores de Transcrição/metabolismo
4.
J Cancer Res Clin Oncol ; 145(10): 2423-2432, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31456088

RESUMO

PURPOSE: The mortality of colorectal cancer ranked fifth in China according to cancer statistics in 2015. Cancer screening had been repeatedly proved to play a vital role in decreasing the incidence and mortality of colorectal cancer, but the existing screening methods could not meet the requirements. So it is of urgent need to develop a non-invasive, convenient and accurate screening method. METHODS: In this study, stool samples were collected from 102 colorectal cancer, 20 colorectal adenoma, 6 hyperplastic polyps patients and 105 normal controls, and stool DNA was extracted for detection of methylation (BMP3, NDRG4, SDC2 and SFRP2) and KRAS mutations. Meanwhile, hemoglobin in stool samples was detected by immunoassays. Then, the logistic regression model used for classification was built with these biomarkers, and a ROC curve was drawn to evaluate the performance of each biomarker and the panel of them. Meanwhile, conventional serum biomarkers were detected for the comparison of positive rate in colorectal cancer between serum biomarkers and stool DNA biomarkers. RESULTS: As a result, a classification model built with methylation of SDC2 and SFRP2, KRAS mutations and hemoglobin showed a sensitivity of 91.4% for colorectal cancer and 60% for adenoma with the specificity of 86.1%. Compared with it, most of the conventional serum biomarkers showed a sensitivity of less than 20% for colorectal cancer which was significantly lower than stool DNA biomarkers. CONCLUSIONS: A novel panel comprised of stool DNA biomarkers was of much higher sensitivity and specificity in early screening of colorectal neoplasms than conventional serum biomarkers.


Assuntos
Biomarcadores Tumorais , Neoplasias Colorretais/genética , DNA de Neoplasias , Fezes/química , Adenoma/diagnóstico , Adenoma/genética , China/epidemiologia , Pólipos do Colo/diagnóstico , Pólipos do Colo/genética , Colonoscopia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Metilação de DNA , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Programas de Rastreamento , Mutação , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas p21(ras)/genética , Curva ROC , Sensibilidade e Especificidade
5.
Gene ; 716: 144033, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31377313

RESUMO

Oral squamous cell cancer (OSCC) is one of the causes of death worldwide. The purpose of this project was to define the restoring of microRNA-143 in HN-5 cells and discover molecular apparatuses responsible for the anticancer processes. Firstly, expression levels of miR-143, K-Ras, MMP9 and C-Myc were evaluated in OSCC tissues. Then, microRNA-143 was transfected into HN-5 cells. The cytotoxic effects of microRNA-143 on HN-5 cells were evaluated. To estimate the effects of microRNA-143 on cell migration, wound healing assay was done. The expression levels of microRNA-143, K-Ras, MMP9, C-Myc, ADAMTS and CXCR4 were evaluated via the qRT-PCR method. microRNA-143 mimic inhibited cell migration in HN-5 cell line. microRNA-143 mimic decreased K-Ras, MMP9, C-My, ADAMTS and CXCR4 gene expression. microRNA-143 can inhibit HN-5 cells migration in vitro by down-regulating the expression of invasion-linked genes. Hence, microRNA-143 can be a new diagnostic biomarker and new therapeutic target for OSCC.


Assuntos
MicroRNAs/metabolismo , Neoplasias Bucais/genética , Neoplasias de Células Escamosas/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Metástase Neoplásica , Neoplasias de Células Escamosas/metabolismo , Neoplasias de Células Escamosas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transfecção
6.
Cancer Sci ; 110(9): 2760-2772, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325400

RESUMO

Long noncoding RNAs (lncRNAs) are emerging as key regulators in cancer initiation and progression. TP53TG1 is a recently identified lncRNA and several studies have shown that TP53TG1 may play the role of tumor suppressor gene or oncogene in different tumors. Nevertheless, the involvement of TP53TG1 in carcinogenesis of pancreatic ductal adenocarcinoma (PDAC) has not been characterized. In our studies, we identified that TP53TG1 was highly expressed in PDAC and was a novel regulator of PDAC development. Knockdown of TP53TG1 inhibited proliferation, induced apoptosis, and decreased migration and invasion in PDAC cells, whereas enhanced expression of TP53TG1 had the opposite effects. Mechanistically, TP53TG1 could directly bind to microRNA (miR)-96 and effectively function as a sponge for miR-96, thus antagonizing the functions of miR-96 and leading to derepression of its endogenous target KRAS, which is a core oncogene in the initiation and maintenance of PDAC. Taken together, these observations imply that TP53TG1 contributes to the growth and progression of PDAC by acting as a competing endogenous RNA (ceRNA) to competitively bind to miR-96 and regulate KRAS expression, which highlights the importance of the complicated miRNA-lncRNA network in modulating the progression of PDAC.


Assuntos
Carcinoma Ductal Pancreático/genética , Proteínas de Ligação a DNA/metabolismo , MicroRNAs/antagonistas & inibidores , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA Longo não Codificante/metabolismo , Carcinogênese/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , RNA Longo não Codificante/genética
7.
Pharm Res ; 36(9): 133, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289919

RESUMO

PURPOSE: KRAS is the most frequently mutated gene in human cancers. Despite its direct involvement in malignancy and intensive effort, direct inhibition of KRAS via pharmacological inhibitors has been challenging. RNAi induced knockdown using siRNAs against mutant KRAS alleles offers a promising tool for selective therapeutic silencing in KRAS-mutant lung cancers. However, the major bottleneck for clinical translation is the lack of efficient biocompatible siRNA carrier systems. METHODS: Bovine serum albumin (BSA) nanoparticles were prepared by desolvation method to deliver siRNA targeting the KRAS G12S mutation. The BSA nanoparticles were characterized with respect to their size, zeta potential, encapsulation efficiency and nucleic acid release. Nanoparticle uptake, cellular distribution of nucleic acids, cytotoxicity and gene knock down to interfere with cancer hallmarks, uncontrolled proliferation and migration, were evaluated in KRAS G12S mutant A459 cells, a lung adenocarcinoma cell line. RESULTS: BSA nanoparticles loaded with siRNA resulted in nanoparticles smaller than 200 nm in diameter and negative zeta potentials, displaying optimal characteristics for in vivo application. Encapsulating and protecting the siRNA payload well, the nanoparticles enabled transport to A549 cells in vitro, could evade endosomal entrapment and mediated significant sequence-specific KRAS knockdown, resulting in reduced cell growth of siRNA transfected lung cancer cells. CONCLUSIONS: BSA nanoparticles loaded with mutant specific siRNA are a promising therapeutic approach for KRAS-mutant cancers.


Assuntos
Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas/química , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , RNA Interferente Pequeno/farmacologia , Soroalbumina Bovina/química , Células A549 , Animais , Apoptose/efeitos dos fármacos , Bovinos , Sobrevivência Celular , Técnicas de Silenciamento de Genes , Terapia Genética , Humanos , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Transfecção
8.
Nat Commun ; 10(1): 2914, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266968

RESUMO

The deubiquitylase OTUD3 plays a suppressive role in breast tumorigenesis through stabilizing PTEN protein, but its role in lung cancer remains unclear. Here, we demonstrate that in vivo deletion of OTUD3 indeed promotes breast cancer development in mice, but by contrast, it slows down KrasG12D-driven lung adenocarcinoma (ADC) initiation and progression and markedly increases survival in mice. Moreover, OTUD3 is highly expressed in human lung cancer tissues and its higher expression correlates with poorer survival of patients. Further mechanistic studies reveal that OTUD3 interacts with, deubiquitylates and stabilizes the glucose-regulated protein GRP78. Knockdown of OTUD3 results in a decrease in the level of GRP78 protein, suppression of cell growth and migration, and tumorigenesis in lung cancer. Collectively, our results reveal a previously unappreciated pro-oncogenic role of OTUD3 in lung cancer and indicate that deubiquitylases could elicit tumor-suppressing or tumor-promoting activities in a cell- and tissue-dependent context.


Assuntos
Proteínas de Choque Térmico/metabolismo , Neoplasias Pulmonares/enzimologia , Proteases Específicas de Ubiquitina/metabolismo , Animais , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Proteínas de Choque Térmico/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteases Específicas de Ubiquitina/genética
9.
Nat Commun ; 10(1): 2919, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266962

RESUMO

Oncogenic mutations in KRAS or BRAF are frequent in colorectal cancer and activate the ERK kinase. Here, we find graded ERK phosphorylation correlating with cell differentiation in patient-derived colorectal cancer organoids with and without KRAS mutations. Using reporters, single cell transcriptomics and mass cytometry, we observe cell type-specific phosphorylation of ERK in response to transgenic KRASG12V in mouse intestinal organoids, while transgenic BRAFV600E activates ERK in all cells. Quantitative network modelling from perturbation data reveals that activation of ERK is shaped by cell type-specific MEK to ERK feed forward and negative feedback signalling. We identify dual-specificity phosphatases as candidate modulators of ERK in the intestine. Furthermore, we find that oncogenic KRAS, together with ß-Catenin, favours expansion of crypt cells with high ERK activity. Our experiments highlight key differences between oncogenic BRAF and KRAS in colorectal cancer and find unexpected heterogeneity in a signalling pathway with fundamental relevance for cancer therapy.


Assuntos
Neoplasias do Colo/enzimologia , Mucosa Intestinal/enzimologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Camundongos , Camundongos Transgênicos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Especificidade da Espécie
10.
Nat Commun ; 10(1): 3055, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296870

RESUMO

KRAS mutations are present in over 90% of pancreatic ductal adenocarcinomas (PDAC), and drive their poor outcomes and failure to respond to targeted therapies. Here we show that Leukemia Inhibitory Factor (LIF) expression is induced specifically by oncogenic KRAS in PDAC and that LIF depletion by genetic means or by neutralizing antibodies prevents engraftment in pancreatic xenograft models. Moreover, LIF-neutralizing antibodies synergize with gemcitabine to eradicate established pancreatic tumors in a syngeneic, KrasG12D-driven, PDAC mouse model. The related cytokine IL-6 cannot substitute for LIF, suggesting that LIF mediates KRAS-driven malignancies through a non-STAT-signaling pathway. Unlike IL-6, LIF inhibits the activity of the Hippo-signaling pathway in PDACs. Depletion of YAP inhibits the function of LIF in human PDAC cells. Our data suggest a crucial role of LIF in KRAS-driven pancreatic cancer and that blockade of LIF by neutralizing antibodies represents an attractive approach to improving therapeutic outcomes.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Fator Inibidor de Leucemia/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Feminino , Técnicas de Inativação de Genes , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Fator Inibidor de Leucemia/antagonistas & inibidores , Fator Inibidor de Leucemia/genética , Camundongos , Mutação , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/genética , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Chem Biol Interact ; 309: 108708, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31199928

RESUMO

Colon cancer is one of the most lethal cancers worldwide even with the significant progress made in screening techniques and therapeutic agents. Genetic mutations in tumors complicated the treatments, and the survival rate remains low for patients at late or metastatic stages. KRAS gene mutation which leads to failure of the EGFR targeted therapies stands for an example of the challenges in clinical sites. Therefore, development of novel agents for colon cancer treatment is in need. Natural and synthetic coumarin derivatives have been suggested with various biological activities with pharmacologic potential including anti-cancer capacity. Here in this study, five coumarin derivatives, include trifluoromethyl-, dimethoxy-, and/or nitro-substitutions at different positions, were synthesized. Their cancer inhibition potential was investigated in various cancer cell lines. Our data demonstrated that one nitro-coumarin derivate, 5,7-Dimethoxy-4-methyl-6-nitro-chromen-2-one, exhibits cytotoxicity specifically towards colon cancer cells under competitive EC50. Our results showed that this compound can effectively suppress colon cancer cells harboring either wild type or mutant KRAS genes, and that it could inhibit short-term proliferation, long term proliferation, and migration capacities of cancer cells. Finally, we demonstrated that this coumarin derivate facilitates cancer cell death through activation of apoptosis pathway. Our results suggest that this coumarin derivate is a promising lead drug worth further investigation and development for future cancer treatment.


Assuntos
Apoptose/efeitos dos fármacos , Cumarínicos/farmacologia , Dióxido de Nitrogênio/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Cumarínicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Mutação
12.
Sheng Wu Gong Cheng Xue Bao ; 35(5): 880-891, 2019 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-31223006

RESUMO

A simple, robust and highly sensitive TB-ARMS method based on qPCR technique was developed to detect kras mutations. The technique was evaluated, and its clinical application was investigated. Mutation specific primers for eight common kras mutations and wild type gene targeted blockers were designed and optimized. Moreover, a mutant-enriched condition was used in to improve the sensitivity and specificity of mutation detection. Constructed plasmids carrying mutant kras genes, as well as confirmed wild type genomic DNA, were used as standard samples for evaluation of the methodology. The performance of our new method was validated by comparing the results of our method with that of a commercial kras kit in testing 40 clinical samples. Preoperative plasma samples, as well as paired tissue samples, were tested in parallel for evaluation of its clinical application. We have developed a new TB-ARMS method for kras mutation detection that can detect minor mutant alleles with a frequency as low as 0.01% in a heterogeneous sample. We have successfully demonstrated its 0.01% detection sensitivity with highly specific mutant amplification in conjunction with selective wild type suppression by blocker under a mutant-enriched reaction condition. We also showed that our TB-ARMS method was more accurate than the commercial kras kit, which is widely used presently. Furthermore, we have validated our method as an efficient liquid biopsy method, and the results of the plasma DNA detection with our TB-ARMS method were in consistent with the sequencing results of paired tissue samples. In conclusion, our TB-ARMS qPCR method could be effectively applied in kras mutation test for clinical tissue samples, as well as for liquid biopsy samples such as plasma.


Assuntos
Técnicas e Procedimentos Diagnósticos , Mutação , Proteínas Proto-Oncogênicas p21(ras) , Reação em Cadeia da Polimerase em Tempo Real , Primers do DNA , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Proteínas Proto-Oncogênicas p21(ras)/genética
13.
Dis Colon Rectum ; 62(7): 832-839, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31188184

RESUMO

BACKGROUND: Mutation analyses provide the basis of selecting an appropriate target agent for the treatment of metastatic colorectal cancer. However, metachronous metastases developed after the treatment of primary tumor could create significant opportunities for different genetic profiles relative to the primary tumors. OBJECTIVE: The purpose of this study was to assess the necessity of genetic evaluation of metachronous metastases; we performed a quantitative analysis of genetic discordance between metachronous metastases and radically resected primary colorectal cancers using next-generation sequencing. DESIGN: This was a retrospective study. SETTINGS: Patients from a single-institution tertiary care center were studied. PATIENTS: We enrolled 33 patients who underwent resection of metachronous metastases between January 2014 and December 2016, ≥6 months after radical resection of primary colorectal cancer and whose tissue was available for analysis. MAIN OUTCOME MEASURES: Tumor samples were analyzed by next-generation sequencing. The mutant allele frequency was analyzed to evaluate the proportion of mutations in the tumor tissue. RESULTS: The mutant allele frequency of KRAS in metachronous metastases was higher in 6 cases (mean difference =% 25.5% (range, 9.5%-58.0%)) and lower in 3 cases (mean difference = 9.3% (range, 8.0-10.0%) compared with each of their primary tumors. In 1 case, the KRAS mutant-type (mutant allele frequency = 22.6%) metachronous metastasis had developed from the KRAS wild-type primary tumor. LIMITATIONS: Tumor sample may not represent perfectly the whole tumor of the patient because of heterogeneity. CONCLUSIONS: Genetic discordance can exist between metachronous metastases and radically resected primary colorectal cancers. For appropriate target therapy, genetic evaluation of metachronous metastases needs to be considered when possible. See Video Abstract at http://links.lww.com/DCR/A932.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/terapia , Análise Mutacional de DNA , Intervalo Livre de Doença , Feminino , GTP Fosfo-Hidrolases/genética , Frequência do Gene , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Proteínas Proto-Oncogênicas B-raf/genética , Estudos Retrospectivos , Proteína Supressora de Tumor p53/genética
14.
Gastroenterology ; 157(4): 1123-1137.e22, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31175866

RESUMO

BACKGROUND & AIMS: Intraductal papillary mucinous neoplasms (IPMNs) are lesions that can progress to invasive pancreatic cancer and constitute an important system for studies of pancreatic tumorigenesis. We performed comprehensive genomic analyses of entire IPMNs to determine the diversity of somatic mutations in genes that promote tumorigenesis. METHODS: We microdissected neoplastic tissues from 6-24 regions each of 20 resected IPMNs, resulting in 227 neoplastic samples that were analyzed by capture-based targeted sequencing. Somatic mutations in genes associated with pancreatic tumorigenesis were assessed across entire IPMN lesions, and the resulting data were supported by evolutionary modeling, whole-exome sequencing, and in situ detection of mutations. RESULTS: We found a high prevalence of heterogeneity among mutations in IPMNs. Heterogeneity in mutations in KRAS and GNAS was significantly more prevalent in IPMNs with low-grade dysplasia than in IPMNs with high-grade dysplasia (P < .02). Whole-exome sequencing confirmed that IPMNs contained multiple independent clones, each with distinct mutations, as originally indicated by targeted sequencing and evolutionary modeling. We also found evidence for convergent evolution of mutations in RNF43 and TP53, which are acquired during later stages of tumorigenesis. CONCLUSIONS: In an analysis of the heterogeneity of mutations throughout IPMNs, we found that early-stage IPMNs contain multiple independent clones, each with distinct mutations, indicating their polyclonal origin. These findings challenge the model in which pancreatic neoplasms arise from a single clone. Increasing our understanding of the mechanisms of IPMN polyclonality could lead to strategies to identify patients at increased risk for pancreatic cancer.


Assuntos
Biomarcadores Tumorais/genética , Transformação Celular Neoplásica/genética , Mutação , Neoplasias Intraductais Pancreáticas/genética , Neoplasias Pancreáticas/genética , Idoso , Idoso de 80 Anos ou mais , Transformação Celular Neoplásica/patologia , Cromograninas/genética , Evolução Clonal , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Evolução Molecular , Feminino , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Taxa de Mutação , Estadiamento de Neoplasias , Proteínas Oncogênicas/genética , Neoplasias Intraductais Pancreáticas/patologia , Neoplasias Pancreáticas/patologia , Fenótipo , Proteínas Proto-Oncogênicas p21(ras)/genética , Estudos Retrospectivos
15.
Nat Commun ; 10(1): 2607, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197133

RESUMO

Inhibiting the RAS oncogenic protein has largely been through targeting the switch regions that interact with signalling effector proteins. Here, we report designed ankyrin repeat proteins (DARPins) macromolecules that specifically inhibit the KRAS isoform by binding to an allosteric site encompassing the region around KRAS-specific residue histidine 95 at the helix α3/loop 7/helix α4 interface. We show that these DARPins specifically inhibit KRAS/effector interactions and the dependent downstream signalling pathways in cancer cells. Binding by the DARPins at that region influences KRAS/effector interactions in different ways, including KRAS nucleotide exchange and inhibiting KRAS dimerization at the plasma membrane. These results highlight the importance of targeting the α3/loop 7/α4 interface, a previously untargeted site in RAS, for specifically inhibiting KRAS function.


Assuntos
Sítio Alostérico/efeitos dos fármacos , Antineoplásicos/farmacologia , Desenho de Drogas , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Repetição de Anquirina , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Histidina/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Neoplasias/genética , Neoplasias/patologia , Biblioteca de Peptídeos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais/efeitos dos fármacos
16.
PLoS Genet ; 15(6): e1008168, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31199785

RESUMO

The lack of predictive preclinical models is a fundamental barrier to translating knowledge about the molecular pathogenesis of cancer into improved therapies. Insertional mutagenesis (IM) in mice is a robust strategy for generating malignancies that recapitulate the extensive inter- and intra-tumoral genetic heterogeneity found in advanced human cancers. While the central role of "driver" viral insertions in IM models that aberrantly increase the expression of proto-oncogenes or disrupt tumor suppressors has been appreciated for many years, the contributions of cooperating somatic mutations and large chromosomal alterations to tumorigenesis are largely unknown. Integrated genomic studies of T lineage acute lymphoblastic leukemias (T-ALLs) generated by IM in wild-type (WT) and Kras mutant mice reveal frequent point mutations and other recurrent non-insertional genetic alterations that also occur in human T-ALL. These somatic mutations are sensitive and specific markers for defining clonal dynamics and identifying candidate resistance mechanisms in leukemias that relapse after an initial therapeutic response. Primary cancers initiated by IM and resistant clones that emerge during in vivo treatment close key gaps in existing preclinical models, and are robust platforms for investigating the efficacy of new therapies and for elucidating how drug exposure shapes tumor evolution and patterns of resistance.


Assuntos
Genômica , Leucemia-Linfoma Linfoblástico de Células T Precursoras/dietoterapia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Linhagem Celular Tumoral , Aberrações Cromossômicas , Evolução Clonal/genética , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Camundongos , Mutagênese Insercional/genética , Mutação , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia
17.
Clin Cancer Res ; 25(15): 4589-4591, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31164372

RESUMO

Approximately 8%-10% of pancreatic ductal adenocarcinoma cases are KRAS wild type. In a subset of these tumors, NRG1 gene fusions have been identified as targetable oncogenic drivers, a discovery that highlights the importance of deep molecular characterization for KRAS wild-type pancreatic cancers and provides a novel treatment strategy in this disease.See related article by Jones et al., p. 4674.


Assuntos
Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas/genética , Carcinogênese , Humanos , Neuregulina-1/genética , Oncogenes , Proteínas Proto-Oncogênicas p21(ras)/genética
19.
Nat Commun ; 10(1): 2569, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189880

RESUMO

Synonymous mutations have been viewed as silent mutations, since they only affect the DNA and mRNA, but not the amino acid sequence of the resulting protein. Nonetheless, recent studies suggest their significant impact on splicing, RNA stability, RNA folding, translation or co-translational protein folding. Hence, we compile 659194 synonymous mutations found in human cancer and characterize their properties. We provide the user-friendly, comprehensive resource for synonymous mutations in cancer, SynMICdb ( http://SynMICdb.dkfz.de ), which also contains orthogonal information about gene annotation, recurrence, mutation loads, cancer association, conservation, alternative events, impact on mRNA structure and a SynMICdb score. Notably, synonymous and missense mutations are depleted at the 5'-end of the coding sequence as well as at the ends of internal exons independent of mutational signatures. For patient-derived synonymous mutations in the oncogene KRAS, we indicate that single point mutations can have a relevant impact on expression as well as on mRNA secondary structure.


Assuntos
Bases de Dados de Ácidos Nucleicos , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias/genética , Mutação Silenciosa/genética , Conjuntos de Dados como Assunto , Humanos , Mutação de Sentido Incorreto/genética , Mutação Puntual/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Dobramento de RNA/genética , Processamento de RNA/genética , RNA Mensageiro/química , RNA Mensageiro/genética
20.
Anticancer Res ; 39(6): 2845-2853, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31177122

RESUMO

BACKGROUND/AIM: Recent studies have shown a marked increase of AT-rich interactive domain 3A (ARID3A) in colon cancer tissue compared to normal colon mucosa. However, the role of ARID3A has not yet been determined in rectal cancer. We, therefore, investigated the clinical relevance of ARID3A expression in patients with residual rectal cancer after neoadjuvant chemoradiotherapy (NACRT). MATERIALS AND METHODS: One hundred thirty-four patients who underwent surgical resection for residual rectal cancer after NACRT were analyzed. ARID3A expression was evaluated using immunohistochemistry on whole-tissue sections. KRAS exon 2 (codons 12 and 13) and BRAF V600E mutation status were determined using polymerase chain reaction. RESULTS: ARID3A positivity was found in 91 cases (64.5%), and it correlated with absence of perineural invasion (p=0.031), longer disease-free survival (DFS) (p=0.048) and cancer-specific survival (CSS) (p=0.006). However, ARID3A positivity was not correlated with KRAS (p=0.231) or BRAF mutation status (p=0.577). In multivariate analysis, ARID3A positivity was independently associated with a favorable CSS (p=0.035), but not DFS (p=0.051). CONCLUSION: ARID3A positivity can predict favorable prognosis in patients with residual rectal cancer after NACRT.


Assuntos
Quimiorradioterapia Adjuvante/métodos , Proteínas de Ligação a DNA/metabolismo , Neoplasia Residual/cirurgia , Neoplasias Retais/terapia , Fatores de Transcrição/metabolismo , Regulação para Cima , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mutação , Terapia Neoadjuvante , Neoplasia Residual/genética , Neoplasia Residual/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Retais/genética , Neoplasias Retais/metabolismo , Estudos Retrospectivos , Resultado do Tratamento
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