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1.
Mol Cancer ; 18(1): 174, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791342

RESUMO

BACKGROUND: Long noncoding RNAs (lncRNAs) play nonnegligible roles in the epigenetic regulation of cancer cells. This study aimed to identify a specific lncRNA that promotes the colorectal cancer (CRC) progression and could be a potential therapeutic target. METHODS: We screened highly expressed lncRNAs in human CRC samples compared with their matched adjacent normal tissues. The proteins that interact with LINRIS (Long Intergenic Noncoding RNA for IGF2BP2 Stability) were confirmed by RNA pull-down and RNA immunoprecipitation (RIP) assays. The proliferation and metabolic alteration of CRC cells with LINRIS inhibited were tested in vitro and in vivo. RESULTS: LINRIS was upregulated in CRC tissues from patients with poor overall survival (OS), and LINRIS inhibition led to the impaired CRC cell line growth. Moreover, knockdown of LINRIS resulted in a decreased level of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), a newly found N6-methyladenosine (m6A) 'reader'. LINRIS blocked K139 ubiquitination of IGF2BP2, maintaining its stability. This process prevented the degradation of IGF2BP2 through the autophagy-lysosome pathway (ALP). Therefore, knockdown of LINRIS attenuated the downstream effects of IGF2BP2, especially MYC-mediated glycolysis in CRC cells. In addition, the transcription of LINRIS could be inhibited by GATA3 in CRC cells. In vivo experiments showed that the inhibition of LINRIS suppressed the proliferation of tumors in orthotopic models and in patient-derived xenograft (PDX) models. CONCLUSION: LINRIS is an independent prognostic biomarker for CRC. The LINRIS-IGF2BP2-MYC axis promotes the progression of CRC and is a promising therapeutic target.

2.
J Cancer ; 10(10): 2299-2311, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31258733

RESUMO

Background: Lymphocytes were reported to play a significant part in host anticancer immune responses and influence tumour prognosis. Few studies have focused on the prognostic values of aspartate aminotransferase (AST) to lymphocyte ratio (ALRI), aspartate aminotransferase to platelet count ratio index (APRI) and systemic immune-inflammation index (SII) in hepatocellular carcinoma (HCC) treated with palliative treatments. Methods: Five hundred and ninety-eight HCC patients treated with palliative therapies were retrospectively analysed. We randomly assigned patients into the training cohort (429 patients) and the validation cohort I (169 patients). Receiver operating characteristic (ROC) curves were used to identify the best cut-off values for the ALRI, APRI and SII in the training cohort and the values were further validated in the validation cohort I. Correlations between ALRI and other clinicopathological factors were also analysed. A prognostic nomogram including ALRI was established. We validated the prognostic value of the ALRI, SII and APRI with two independent cohorts, the validation cohort II of 82 HCC patients treated with TACE and the validation cohort III of 150 HCC patients treated with curative resection. In the training cohort and all the validation cohorts, univariate analyses by the method of Kaplan-Meier and multivariate analysis by Cox proportional hazards regression model were carried out to identify the independent prognostic factors. Results: The threshold values of ALRI, APRI and SII were 86.3, 1.37 and 376.4 respectively identified by ROC curve analysis in the training cohort. Correlation analysis showed that ALRI>86.3 was greatly associated with higher rates of Child-Pugh B&C, portal vein tumor thrombosis (PVTT) and ascites (P < 0.05). Correspondingly, ALRI level of HCC patients with Child-Pugh B&C, PVTT and ascites was evidently higher than that of HCC patients with Child-Pugh A, without PVTT and without ascites (P < 0.001). In the training cohort and the validation cohort I, II, III, the OS of patients with ALRI >86.3 was obviously shorter than patients with ALRI ≤86.3 (P <0.001). We identified ALRI as an independent prognostic factor by univariate and multivariate analyses both in training Cohort (HR=1.481, P=0.004), validation cohort I (HR=1.511, P=0.032), validation cohort II (HR=3.166, P=0.005) and validation cohort III (HR=3.921, P=0.010). The SII was identified as an independent prognostic factor in training cohort (HR=1.356, P=0.020) and the validation cohort II (HR=2.678, P=0.002). The prognostic nomogram including ALRI was the best in predicting 3-month, 6-month, 1-year, 2-year survival And OS among TNM, ALRI, ALRI-TNM and nomogram. Conclusions: The ALRI was a novel independent prognostic index for the HCC patients treated with palliative treatments.

4.
Mol Cancer ; 18(1): 112, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31230592

RESUMO

BACKGROUND: Colorectal carcinoma (CRC) is one of the most common malignant tumors, and its main cause of death is tumor metastasis. RNA N6-methyladenosine (m6A) is an emerging regulatory mechanism for gene expression and methyltransferase-like 3 (METTL3) participates in tumor progression in several cancer types. However, its role in CRC remains unexplored. METHODS: Western blot, quantitative real-time PCR (RT-qPCR) and immunohistochemical (IHC) were used to detect METTL3 expression in cell lines and patient tissues. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of METTL3. The biological functions of METTL3 were investigated in vitro and in vivo. RNA pull-down and RNA immunoprecipitation assays were conducted to explore the specific binding of target genes. RNA stability assay was used to detect the half-lives of the downstream genes of METTL3. RESULTS: Using TCGA database, higher METTL3 expression was found in CRC metastatic tissues and was associated with a poor prognosis. MeRIP-seq revealed that SRY (sex determining region Y)-box 2 (SOX2) was the downstream gene of METTL3. METTL3 knockdown in CRC cells drastically inhibited cell self-renewal, stem cell frequency and migration in vitro and suppressed CRC tumorigenesis and metastasis in both cell-based models and PDX models. Mechanistically, methylated SOX2 transcripts, specifically the coding sequence (CDS) regions, were subsequently recognized by the specific m6A "reader", insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), to prevent SOX2 mRNA degradation. Further, SOX2 expression positively correlated with METTL3 and IGF2BP2 in CRC tissues. The combined IHC panel, including "writer", "reader", and "target", exhibited a better prognostic value for CRC patients than any of these components individually. CONCLUSIONS: Overall, our study revealed that METTL3, acting as an oncogene, maintained SOX2 expression through an m6A-IGF2BP2-dependent mechanism in CRC cells, and indicated a potential biomarker panel for prognostic prediction in CRC.

5.
J Exp Clin Cancer Res ; 38(1): 196, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088567

RESUMO

BACKGROUND: Deregulation of protein translation control is a hallmark of cancers. Eukaryotic initiation factor 4A2 (EIF4A2) is required for mRNA binding to ribosome and plays an important role in translation initiation. However, little is known about its functions in colorectal cancer (CRC). METHODS: Analysis of CRC transcriptome data from TCGA identified that EIF4A2 was associated with poor prognosis. Immunohistochemistry study of EIF4A2 was carried out in 297 paired colorectal tumor and adjacent normal tissue samples. In vitro and in vivo cell-biological assays were performed to study the biological functions of EIF4A2 on experimental metastasis and sensitivity to oxaliplatin treatment. Bioinformatic prediction, chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assay were carried out to unveil the transcription factor of EIF4A2 regulation. RESULTS: EIF4A2 Expression is significantly higher in colorectal tumors. Multivariate analysis suggests EIF4A2 as an independent predictor of overall, disease-free and progression-free survival. Dysfunction of EIF4A2 by genetic knock-down or small-molecule inhibitor silvestrol dramatically inhibited CRC invasion and migration, sphere formation and enhanced sensitivity to oxaliplatin treatment in vitro and in vivo. Notably, EIF4A2 knock-down also suppressed lung metastasis in vivo. qRT-PCR and immunoblotting analyses identified c-Myc as a downstream target and effector of EIF4A2. ChIP and dual-luciferase reporter assays validated the bioinformatical prediction of ZNF143 as a specific transcription factor of EIF4A2. CONCLUSIONS: EIF4A2 promotes experimental metastasis and oxaliplatin resistance in CRC. Silvestrol inhibits tumor growth and has synergistic effects with oxaliplatin to induce apoptosis in cell-derived xenograft (CDX) and patient-derived xenograft (PDX) models.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/metabolismo , Resistencia a Medicamentos Antineoplásicos , Fator de Iniciação 4A em Eucariotos/metabolismo , Oxaliplatina/farmacologia , Adulto , Idoso , Animais , Biomarcadores , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Cancer Res ; 78(8): 1972-1985, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29654155

RESUMO

Genomic alterations of tumor suppressorsoften encompass collateral protein-coding genes that create therapeutic vulnerability to further inhibition of their paralogs. Here, we report that malic enzyme 2 (ME2) is frequently hemizygously codeleted with SMAD4 in gastric cancer. Its isoenzyme ME1 was upregulated to replenish the intracellular reducing equivalent NADPH and to maintain redox homeostasis. Knockdown of ME1 significantly depleted NADPH, induced high levels of reactive oxygen species (ROS), and ultimately cell apoptosis under oxidative stress conditions, such as glucose starvation and anoikis, in ME2-underexpressed cells. Moreover, ME1 promoted tumor growth, lung metastasis, and peritoneal dissemination of gastric cancer in vivo Intratumoral injection of ME1 siRNA significantly suppressed tumor growth in cell lines and patient-derived xenograft-based models. Mechanistically, ME1 was transcriptionally upregulated by ROS in an ETV4-dependent manner. Overexpression of ME1 was associated with shorter overall and disease-free survival in gastric cancer. Altogether, our results shed light on crucial roles of ME1-mediated production of NADPH in gastric cancer growth and metastasis.Significance: These findings reveal the role of malic enzyme in growth and metastasis.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/8/1972/F1.large.jpg Cancer Res; 78(8); 1972-85. ©2018 AACR.


Assuntos
Proliferação de Células/fisiologia , Homeostase/fisiologia , Neoplasias Pulmonares/secundário , Malato Desidrogenase/fisiologia , NADP/metabolismo , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/patologia , Proteínas E1A de Adenovirus/fisiologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Regulação para Baixo , Feminino , Glucose/metabolismo , Xenoenxertos , Humanos , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Proteínas Proto-Oncogênicas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteína Smad4/genética , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/metabolismo , Regulação para Cima
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