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1.
Oncogene ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31740780

RESUMO

H1 histamine receptor (H1HR) belongs to the family of rhodopsin-like G-protein-coupled receptors. Recent studies have shown that H1HR expression is increased in several types of cancer. However, its functional roles in tumor progression remain largely unknown, especially in hepatocellular carcinoma (HCC). We found that H1HR is frequently unregulated in HCC, which is significantly associated with both recurrence-free survival and overall survival in HCC patients. Functional experiments revealed that H1HR promoted both the growth and metastasis of HCC cells by inducing cell cycle progression, formation of lamellipodia, production of matrix metalloproteinase 2, and suppression of cell apoptosis. Activation of cyclic adenosine monophosphate-dependent protein kinase A was found to be involved in H1HR-mediated HCC cell growth and metastasis. In addition, we found that overexpression of H1HR was mainly due to the downregulation of miR-940 in HCC cells. Moreover, the H1HR inhibitor terfenadine significantly suppressed tumor growth and metastasis in an HCC xenograft nude mice model. Our findings demonstrate that H1HR plays a critical role in the growth and metastasis of HCC cells, which provides experimental evidence supporting H1HR as a potential drug target for the treatment of HCC.

2.
J Exp Clin Cancer Res ; 38(1): 402, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519193

RESUMO

BACKGROUND: Dihydroartemisinin (DHA) has been shown to exert anticancer activity through iron-dependent reactive oxygen species (ROS) generation, which is similar to ferroptosis, a novel form of cell death. However, whether DHA causes ferroptosis in glioma cells and the potential regulatory mechanisms remain unclear. METHODS: Effects of DHA on the proliferation, cell death, ROS and lipid ROS generation as well as reduced gluthione consumption were assessed in glioma cells with or without ferroptosis inhibitor. The biological mechanisms by which glioma cells attenuate the pro-ferroptotic effects of DHA were assessed using molecular methods. RESULTS: DHA induced ferroptosis in glioma cells, as characterized by iron-dependent cell death accompanied with ROS generation and lipid peroxidation. However, DHA treatment simultaneously activated a feedback pathway of ferroptosis by increasing the expression of heat shock protein family A (Hsp70) member 5 (HSPA5). Mechanistically, DHA caused endoplasmic reticulum (ER) stress in glioma cells, which resulted in the induction of HSPA5 expression by protein kinase R-like ER kinase (PERK)-upregulated activating transcription factor 4 (ATF4). Subsequent HSPA5 upregulation increased the expression and activity of glutathione peroxidase 4 (GPX4), which neutralized DHA-induced lipid peroxidation and thus protected glioma cells from ferroptosis. Inhibition of the PERK-ATF4-HSPA5-GPX4 pathway using siRNA or small molecules increased DHA sensitivity of glioma cells by increasing ferroptosis both in vitro and in vivo. CONCLUSIONS: Collectively, these data suggested that ferroptosis might be a novel anticancer mechanism of DHA in glioma and HSPA5 may serve as a negative regulator of DHA-induced ferroptosis. Therefore, inhibiting the negative feedback pathway would be a promising therapeutic strategy to strengthen the anti-glioma activity of DHA.

3.
Cancer Lett ; 461: 44-55, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31278950

RESUMO

Succinate dehydrogenase is a heterotetrameric complex comprising four nuclear-encoded subunits, catalyzes the oxidation of succinate to fumarate in the tricarboxylic acid cycle. A subset of cancers have been found to be associated with mutations in the four SDH genes. However, the functional roles of the SDH complex in tumorigenesis remain largely unclear, especially in hepatocellular carcinoma (HCC). Here, we investigated the expression levels of the four SDH subunits and their clinical significance in HCC, followed by systematic exploration of the effects of SDH dysfunction on HCC cell survival and metastasis both in vitro and in vivo, as well as the underlying molecular mechanisms. Our results showed that the expression of the SDHA/B/C/D subunits was significantly downregulated in HCC, associated with poor patient prognosis, and contributed to SDH inactivation. Additionally, attenuated SDH activity following SDHC knockdown promoted HCC-cell growth and metastasis both in vitro and in vivo via elevated reactive oxygen species levels and subsequent activation of nuclear factor-κB signaling. These findings suggest a critical tumor-suppressive role for SDH and provide strong evidence supporting this enzyme as a potential drug target in the treatment of HCC.

4.
J Mol Diagn ; 21(4): 593-601, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026598

RESUMO

Heteroplasmic mutations in mitochondrial DNA (mtDNA) play critical roles in mitochondrial disease, aging, and cancer. Recently, next-generation sequencing (NGS) has been widely used to detect mtDNA mutations for diagnosis and monitoring of the above-mentioned diseases. However, little attention is paid on inherent cross-contamination generated during mtDNA capture and sequencing of mixed samples, which may seriously reduce the detection accuracy of mtDNA heteroplasmic mutations. In this study, a novel sequencing strategy based on a unique double-barcode design was established. The results showed that when single barcode-based analysis strategy was used, cross-contamination level of 20 DNA samples ranged from 0.27% to 11.90% on HiSeq 2500 and from 0.93% to 17.70% on HiSeq X ten, whereas double barcode-based strategy could effectively eliminate cross-contamination. Moreover, the data indicated that cross-contamination was mainly derived from capture process and was significantly affected by different NGS platforms. In addition, contamination level was negatively related to sequencing depth. Moreover, cross-contamination significantly increased the false-positive calling of mtDNA heteroplasmic mutations and remarkably affected the heteroplasmy level of mtDNA mutations. In contrast, cross-contamination had no notable effect on classification of mtDNA haplogroup. Taken together, our novel double barcode-based sequencing strategy is effective in eliminating cross-contamination, enhancing the detection accuracy of mtDNA NGS, and improving its application in diagnosis or monitoring of diseases associated with mtDNA mutations.

5.
J Exp Clin Cancer Res ; 38(1): 136, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909929

RESUMO

BACKGROUND: Mitochondrial Ca2+ plays a critical role in tumorigenesis, including cell proliferation and metastasis. Mitochondrial calcium uniporter regulator 1 (MCUR1) has been shown to be frequently upregulated in HCC and promote cancer cell survival. However, whether MCUR1 is involved in the metastasis of HCC and its underlying mechanisms remain unknown. METHODS: The effect of MCUR1 expression on epithelial-mesenchymal transition (EMT) in HCC cells was first evaluated by immunofluorescent staining and Western blot. Then, in vitro invasion and in vivo metastasis assays were used to evaluate the function of MCUR1 in HCC metastasis. The underlying mechanism has also been explored by investigating the effect of MCUR1 on ROS/Nrf2/Notch1 pathway. RESULTS: MCUR1 expression was significantly higher in HCC with metastasis and associated with tumor progression. MCUR1 promoted in vitro invasion and in vivo metastasis of HCC cells by promoting EMT via Snail. Mechanistically, MCUR1-mediated mitochondrial Ca2+ signaling promoted the EMT of HCC cells by activating ROS/Nrf2/Notch1 pathway. Inhibition of ROS production, mitochondrial Ca2+ uptake, Nrf2 expression or Notch1 activity significantly suppressed MCUR1-induced EMT of HCC cells. In addition, treatment with the mitochondrial Ca2+-buffering protein parvalbumin significantly inhibited ROS/Nrf2/Notch pathway and MCUR1-induced EMT and HCC metastasis. CONCLUSIONS: Our study provides evidence supporting a metastasis-promoting role for MCUR1-dependent mitochondrial Ca2+ uptake in HCC. Our findings suggest that MCUR1 may be a potential therapeutic target for HCC treatment.


Assuntos
Cálcio/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Transdução de Sinais , Animais , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Progressão da Doença , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Estadiamento de Neoplasias , Transplante de Neoplasias , Espécies Reativas de Oxigênio/metabolismo , Receptores Notch/metabolismo , Regulação para Cima
6.
Oncogene ; 38(25): 5007-5020, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30894684

RESUMO

Tumor-associated macrophages (TAMs) contribute to hepatocellular carcinoma (HCC) progression. However, the molecular mechanism underlying the infiltration of TAMs into HCC microenvironment is largely unclear. Recent studies have reported that alteration of mitochondrial nucleoid structures induces mitochondrial DNA (mtDNA) release into the cytosol, which is recognized as mtDNA stress, and consequently regulates innate immunity. Here we aimed to investigate whether mitochondrial fission induces mtDNA stress and then promotes TAM infiltration and HCC progression. Confocal microscopy and real-time PCR were used to detect cytosolic mtDNA content in HCC cells. The relationship between the expression of mitochondrial fission key regulator dynamin-related protein 1 (Drp1) and the percentage of CD163 (a marker of TAMs)-positive cells was investigated in HCC tissues using immunohistochemistry. Finally, the effect of Drp1 overexpression in HCC cells on recruitment and polarization of TAMs was investigated. Our data showed that increased Drp1 expression was positively correlated with the infiltration of TAMs into HCC tissues. Drp1-mediated mitochondrial fission induced the cytosolic mtDNA stress to enhance the CCL2 secretion from HCC cells by TLR9-mediated NF-κB signaling pathway, and thus promoted the TAM recruitment and polarization. Depleting cytosolic mtDNA using DNase I or blocking TLR9 pathway by TLR9 antagonist, siRNA for TLR9 or p65 in HCC cells with Drp1 overexpression significantly decreased the recruitment and polarization of TAMs. Blocking CCR2 by antagonist significantly reduced TAM infiltration and suppressed HCC progression in mouse model. In conclusion, our findings reveal a novel mechanism of TAM infiltration in HCC by mitochondrial fission-induced mtDNA stress.

7.
Mol Carcinog ; 58(6): 957-966, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30693981

RESUMO

Sporadic colorectal cancer (sCRC) is one of the leading causes of cancer death worldwide. As a highly heterogeneous complex disease, the currently reported classical genetic markers for sCRC, including APC, KRAS, BRAF, and TP53 gene mutations and epigenetic alterations, can explain only some sCRC patients. Here, we first reported a deleterious c.551C>T mutation in SARDH in sCRC. SARDH was identified as a novel tumor suppressor gene and was abnormally decreased in sCRC at both the transcriptional and the translational level. SARDH mRNA levels were also down-regulated in oesophageal cancer, lung cancer, liver cancer, and pancreatic cancer in the TCGA database. SARDH overexpression inhibited the proliferation, migration, and invasion of CRC cell lines, whereas its depletion improved these processes. SARDH overexpression was down-regulated in multiple pathways, especially in the chemokine pathway. The SARDH transcript level was positively correlated with the methylation states of CXCL1 and CCL20. Therefore, we concluded that SARDH depletion is involved in the development of sCRC.


Assuntos
Neoplasias Colorretais/patologia , Perfilação da Expressão Gênica/métodos , Mutação Puntual , Sarcosina Desidrogenase/genética , Sarcosina Desidrogenase/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Quimiocina CCL20/genética , Quimiocina CXCL1/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Metilação de DNA , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Processamento de RNA , Sequenciamento Completo do Exoma
8.
Int J Cancer ; 144(10): 2516-2528, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30415472

RESUMO

It is now widely accepted that mitochondrial biogenesis is inhibited in most cancer cells. Interestingly, one of the possible exceptions is colorectal cancer (CRC), in which the content of mitochondria has been found to be higher than in normal colon mucosa. However, to date, the causes and effects of this phenomenon are still unclear. In the present study, we systematically investigated the functional role of mitochondrial single-strand DNA binding protein (mtSSB), a key molecule in the regulation of mitochondrial DNA (mtDNA) replication, in the mitochondrial biogenesis and CRC cell growth. Our results demonstrated that mtSSB was frequently upregulated in CRC tissues and that upregulated mtSSB was associated with poor prognosis in CRC patients. Furthermore, overexpression of mtSSB promoted CRC cell growth in vitro by regulating cell proliferation. The in vivo assay confirmed these results, indicating that the forced expression of mtSSB significantly increases the growth capacity of xenograft tumors. Mechanistically, the survival advantage conferred by mtSSB was primarily caused by increased mitochondrial biogenesis and subsequent ROS production, which induced telomerase reverse transcriptase (TERT) expression and telomere elongation via Akt/mTOR pathway in CRC cells. In addition, FOXP1, a member of the forkhead box family, was identified as a new transcription factor for mtSSB. Moreover, our results also demonstrate that proinflammatory IL-6/STAT3 signaling facilitates mtSSB expression and CRC cell proliferation via inducing FOXP1 expression. Collectively, our findings demonstrate that mtSSB induced by inflammation plays a critical role in the regulation of mitochondrial biogenesis, telomerase activation, and subsequent CRC proliferation, providing a strong evidence for mtSSB as drug target in CRC treatment.


Assuntos
Proliferação de Células/genética , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Interleucina-6/genética , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Telomerase/genética , Regulação para Cima/genética , Linhagem Celular Tumoral , DNA Mitocondrial/genética , Humanos , Biogênese de Organelas , Fator de Transcrição STAT3 , Transdução de Sinais/genética , Ativação Transcricional/genética
9.
Eur J Cancer ; 106: 133-143, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30528798

RESUMO

BACKGROUND: Both circulating tumour cell (CTC) and total circulating cell-free DNA (ccfDNA) predict cancer patient prognosis. However, no study has explored the prognostic value of the combined use of CTC and ccfDNA. We aimed to investigate individual and joint effects of CTC and ccfDNA on clinical outcomes of metastatic breast cancer (MBC) patients. METHODS: We collected 227 blood samples from 117 MBC patients. CTCs were enumerated using the CellSearch System. ccfDNAs were quantified by quantitative real-time polymerase chain reaction and Qubit fluorometer. The individual and joint effects of CTC and ccfDNA levels on patient progression-free survival (PFS) and overall survival (OS) were analysed using Cox proportional hazards models. RESULTS: Compared to patients with <5 CTCs, patients with ≥5 CTCs had a 2.58-fold increased risk of progression and 3.63-fold increased risk of death. High level of ccfDNA was associated with a 2.05-fold increased risk of progression and 3.56-fold increased risk of death. These associations remained significant after adjusting for other important clinical covariates and CTC/ccfDNA levels. CTC and ccfDNA levels had a joint effect on patient outcomes. Compared to patients with low levels of both CTC and ccfDNA, those with high levels of both markers exhibited a >17-fold increased death risk (P < 0.001). Moreover, longitudinal analysis of 132 samples from 22 patients suggested that the inconsistency between CTC level and outcome in some patients could possibly be explained by ccfDNA level. CONCLUSIONS: CTC and total ccfDNA levels were individually and jointly associated with PFS and OS in MBC patients.

10.
Mol Cancer ; 17(1): 176, 2018 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30572883

RESUMO

BACKGROUND: Although the genetic spectrum of human colorectal cancer (CRC) is mainly characterized by APC, KRAS and TP53 mutations, driver genes in tumor initiation have not been conclusively demonstrated. In this study, we aimed to identify novel markers for CRC. METHODS: We performed exome analysis of sporadic colorectal cancer (sCRC) coding regions to screen loss of function (LoF) mutation genes, and carried out systems-level approaches to confirm top rank gene in this study. RESULTS: We identified loss of BMP5 is an early event in CRC. Deep sequencing identified BMP5 was mutated in 7.7% (8/104) of sCRC samples, with 37.5% truncating mutation frequency. Notably, BMP5 negative expression and its prognostic value is uniquely significant in sCRC but not in other tumor types. Furthermore, BMP5 expression was positively correlated with E-cadherin in CRC patients and its dysregulation play a vital role in epithelial-mesenchymal transition (EMT), thus triggering tumor initiation and development. RNA sequencing identified, independent of BMP/Smads pathway, BMP5 signaled though Jak-Stat pathways to inhibit the activation of oncogene EPSTI1. CONCLUSIONS: Our result support a novel concept that the importance of BMP5 in sCRC. The tumor suppressor role of BMP5 highlights its crucial role in CRC initiation and development.


Assuntos
Proteína Morfogenética Óssea 5/genética , Neoplasias Colorretais/genética , Proteínas Supressoras de Tumor/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Transição Epitelial-Mesenquimal/genética , Perfilação da Expressão Gênica/métodos , Células HCT116 , Células HT29 , Humanos , Mutação/genética , Transdução de Sinais , Proteínas Smad/genética , Transcriptoma
11.
Cell Death Dis ; 9(11): 1050, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30323195

RESUMO

Mitochondrial morphology is remodeled by continuous dynamic cycles of fission and fusion. Emerging data have shown that the disturbance of balance between mitochondrial fission and fusion is involved in the progression of several types of neoplasms. However, the status of mitochondrial dynamics and its potential biological roles in breast cancer (BC), particularly in triple negative BC (TNBC) are not fully clear. Here, we reported that the mitochondrial fission was significantly increased in BC tissues, especially in the TNBC tissues, when compared with that in the corresponding peritumor tissues. Meanwhile, our data showed that Drp1 was upregulated, while Mfn1 was downregulated in TNBC. Moreover, elevated mitochondrial fission was associated with poorer prognosis in TNBC patients. Mitochondrial fission promoted the survival of TNBC cells both in vitro and in vivo. Furthermore, we identified a positive feedback loop between mitochondrial fission and Notch signaling pathway in TNBC cells, as proved by the experimental evidence that the activation of Notch signaling enhanced Drp1-mediated mitochondrial fission and Drp1-mediated mitochondrial fission in turn promoted the activation of Notch signaling, which ultimately promoted the cell survival of TNBC via increasing survivin expression level. Inhibition of either Notch1 or Drp1 significantly impaired the activation of the other, leading to the suppression of TNBC cell survival and proliferation. Collectively, our data reveal a novel mechanism that the positive feedback loop between mitochondrial fission and Notch signaling promotes the survival, proliferation and apoptotic resistance of TNBC cells via increasing survivin expression and thus favors cancer progression.

12.
Huan Jing Ke Xue ; 39(3): 1342-1349, 2018 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965482

RESUMO

In this study, a CEM-UF composite membrane with ammonia nitrogen enrichment and separation characteristics was combined with nitrification/denitrification to treat low C/N wastewater. The denitrification characteristics of low C/N wastewater at different flow ratios were investigated, and the structural characteristics of functional microbial communities in nitrifying and denitrifying activated sludge were analyzed by 16Sr DNA high-throughput sequencing. The results showed that influent TN was 60 mg·L-1, COD/TN was 2.65, the nitrification effect of each flow rate was good, and the average ammonia nitrogen removal rate was 98.7%. When the flow ratio increased from 1:2 to 1:6, the m(COD)/m(NO3--N) of denitrification was increased, and the removal of average nitrate nitrogen reached its highest level at 1:6, which was 86.28%, and the removal of total nitrogen increased from 22.56% to 46.8%. An analysis of Illumina sequencing showed that nitrogen fixing bacteria Proteobacteria accounted for 30.9%, and the important nitrite oxidizing bacteria, Nitrospirae, accounted for 3.06%. At the genus level, Nitrosomonas and Nitrosospira, belonging to the ammonia oxidizing bacteria (AOB) category and Nitrospira and Nitrobacter, belonging to the nitrite oxidizing bacteria (NOB) category were detected. The ratio of AOB and NOB bacteria was high, which is consistent with good nitrification in the nitrification reactor. The dominant bacteria in denitrification sludge were Proteobacteria (53.13%), followed by Bacteroidetes (10.93%). A variety of bacteria related to denitrification were detected at the genus level, such as Dechloromonas, Thauera, Castellaniella, Alicycliphilus, Azospira, Comamonas, Caldilinea, and Saccharibacteria. The proportion of denitrifying bacteria was 25.91% as denitrifying bacteria microbial species were rich in the denitrifying sludge, giving a good denitrification effect.


Assuntos
Reatores Biológicos , Desnitrificação , Nitrificação , Águas Residuárias/química , Purificação da Água , Amônia , Bactérias , Carbono/química , Nitrogênio/química
13.
Artigo em Inglês | MEDLINE | ID: mdl-29610678

RESUMO

Colorectal cancer is one of the leading causes of cancer death worldwide. According to global genomic status, colorectal cancer can be classified into two main types: microsatellite-stable and microsatellite-instable tumors. Moreover, the two subtypes also exhibit different responses to chemotherapeutic agents through distinctive molecular mechanisms. Recently, mitochondrial DNA depletion has been shown to induce apoptotic resistance in microsatellite-instable colorectal cancer. However, the effects of altered mitochondrial DNA copy number on the progression of microsatellite-stable colorectal cancer, which accounts for the majority of colorectal cancer, remain unclear. In this study, we systematically investigated the functional role of altered mitochondrial DNA copy number in the survival and metastasis of microsatellite-stable colorectal cancer cells. Moreover, the underlying molecular mechanisms were also explored. Our results demonstrated that increased mitochondrial DNA copy number by forced mitochondrial transcription factor A expression significantly facilitated cell proliferation and inhibited apoptosis of microsatellite-stable colorectal cancer cells both in vitro and in vivo. Moreover, we demonstrated that increased mitochondrial DNA copy number enhanced the metastasis of microsatellite-stable colorectal cancer cells. Mechanistically, the survival advantage conferred by increased mitochondrial DNA copy number was caused in large part by elevated mitochondrial oxidative phosphorylation. Furthermore, treatment with oligomycin significantly suppressed the survival and metastasis of microsatellite-stable colorectal cancer cells with increased mitochondrial DNA copy number. Our study provides evidence supporting a possible tumor-promoting role for mitochondrial DNA and uncovers the underlying mechanism, which suggests a potential novel therapeutic target for microsatellite-stable colorectal cancer.

14.
J Exp Clin Cancer Res ; 37(1): 43, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29506556

RESUMO

BACKGROUND: Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. METHODS: The level of cytosolic Ca2+ was assessed by Fura-2 in HCC cells. After changing cytosolic Ca2+ level by using agonists or inhibitors, cell apoptosis was detected by flow cytometry. We also detected the effect of ionomycin or parvalbumin on the anti-tumor activity of TNFα in a mice model. Lastly, we studied the roles of cytosolic Ca2+ in the mitochondrial-dependent intrinsic apoptosis pathway. RESULTS: Here, we demonstrated that TNFα induced extracellular Ca2+ influx into cytoplasm through transient receptor potential channel in HCC cells. Both cytosolic Ca2+ scavenger and Ca2+-binding protein PV effectively desensitized hepatocellular carcinoma cells to TNFα, whereas combination ionomycin or 1,4,5-inositol triphosphate significantly sensitized HCC cells to TNFα, indicating that the increased level of cytosolic Ca2+ was positively correlated with the TNFα-induced cell apoptosis in vitro. In a nude mice xenograft model, our data revealed that TNFα combined with ionomycin remarkably synergized the anti-tumor effect of TNFα. Furthermore, we found that TNFα-mediated extracellular Ca2+ influx accelerated TNFα-induced extrinsic apoptosis through activating calpain/IAP/caspase3 pathway. CONCLUSIONS: Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular Ca2+ influx to enhance cell apoptosis and suggests that increasing the level of cytosolic Ca2+ might be an alternative strategy to improve the pro-apoptotic activity of TNFα in HCC cells, although suitable chemical or biological reagents need to be further tested.


Assuntos
Apoptose , Cálcio/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Biomarcadores , Calpaína/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Espaço Extracelular/metabolismo , Humanos , Potencial da Membrana Mitocondrial , Camundongos , Mitocôndrias/metabolismo , Modelos Biológicos , RNA Interferente Pequeno/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Canais de Receptores Transientes de Potencial/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Int J Cancer ; 143(5): 1143-1152, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29569724

RESUMO

Recent studies have revealed significant intratumor heterogeneity (ITH) of nuclear genome mutations and highlighted its function in tumor progression and treatment resistance. However, the ITH of somatic mitochondrial DNA (mtDNA) mutations detected in cancers remains unknown. In this study, we performed multiregional mtDNA sequencing of tumor and paratumor tissue samples from 12 hepatocellular carcinoma (HCC) and 13 colorectal cancer (CRC) patients. A substantial level of mtDNA mutations was found in paired non-HCC inflammatory tissues, suggesting that these tissues might not be mtDNA-genetically "normal." Moreover, our data indicated that the ITH of somatic mtDNA mutations was a common feature in HCC and CRC patients. In addition, we found that shared mutations which were observed in at least 2 samples in each patient exhibited a significantly higher heteroplasmic level than mutations that were private to a specific tumor region from both HCC (p = 0.039) and CRC patients (p = 0.001). The heteroplasmic level of shared mutations was positively correlated with intratumoral recurrence of mtDNA mutations. We also found that shared mutations in tumor tissues with a higher degree of pathogenicity risk exhibited a higher heteroplasmic level and intratumoral recurrence in both HCC and CRC patients. These findings suggest that some mtDNA mutations may undergo positive selection during the clonal expansion. Taken together, our analyses identified various levels of ITH of somatic mtDNA mutations in HCC and CRC patients and provided evidence supporting the positive selection working on some somatic mtDNA mutations in tumor tissues.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/patologia , Neoplasias Colorretais/patologia , DNA Mitocondrial/genética , Neoplasias Hepáticas/patologia , Mutação , Carcinoma Hepatocelular/genética , Neoplasias Colorretais/genética , Genoma Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias Hepáticas/genética , Prognóstico
16.
Clin Cancer Res ; 24(4): 906-915, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29246937

RESUMO

Purpose: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. In China, chronic hepatitis B virus (HBV) infection remains the major risk factor for HCC. In this study, we performed a genome-wide association study (GWAS) among Chinese populations to identify novel genetic loci contributing to susceptibility to HBV-related HCC.Experimental Design: GWAS scan is performed in a collection of 205 HBV-related HCC trios (each trio includes an affected proband and his/her both parents), and 355 chronic HBV carriers with HCC (cases) and 360 chronic HBV carriers without HCC (controls), followed by two rounds of replication studies totally consisting of 3,796 cases and 2,544 controls.Results: We identified a novel association signal within the CDK14 gene at 7q21.13 (index rs10272859, OR = 1.28, P = 9.46 × 10-10). Furthermore, we observed that the at-risk rs10272859[G] allele was significantly associated with higher mRNA expression levels of CDK14 in liver tissues. Chromosome conformation capture assays in liver cells confirmed that a physical interaction exists between the promoter region of CDK14 and the risk-associated SNPs in strong linkage disequilibrium with the index rs10272859 at 7q21.13. This index rs10272859 also showed significant association with the survival of HCC patients.Conclusions: Our findings highlight a novel locus at 7q21.13 conferring both susceptibility and prognosis to HBV-related HCC, and suggest the CDK14 gene to be the functional target of the 7q21.13 locus. Clin Cancer Res; 24(4); 906-15. ©2017 AACR.


Assuntos
Carcinoma Hepatocelular/genética , Cromossomos Humanos Par 7/genética , Quinases Ciclina-Dependentes/genética , Estudo de Associação Genômica Ampla , Hepatite B Crônica/genética , Neoplasias Hepáticas/genética , Adulto , Grupo com Ancestrais do Continente Asiático/genética , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/etnologia , Estudos de Casos e Controles , China , Feminino , Predisposição Genética para Doença/etnologia , Predisposição Genética para Doença/genética , Hepatite B Crônica/complicações , Hepatite B Crônica/etnologia , Humanos , Desequilíbrio de Ligação , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/etnologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Análise de Sobrevida
17.
Liver Int ; 38(7): 1263-1272, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29210177

RESUMO

BACKGROUND & AIMS: Mitochondrial dynamics of fission and fusion plays critical roles in a diverse range of important cellular functions, and its deregulation has been increasingly implicated in human diseases. Previous studies have shown that increased mitochondrial fission significantly promoted the proliferation of hepatocellular carcinoma (HCC) cells. However, how they influence the migration of tumour cells remained largely unknown. METHODS: In the present study, we further investigated the effect of mitochondrial fission on the migration and metastasis of hepatocellular carcinoma cells. Moreover, the underlying molecular mechanisms and therapeutic application were explored. RESULTS: Our data showed that dynamin-1-like protein expression was strongly increased in distant metastasis of hepatocellular carcinoma when compared to primary hepatocellular carcinoma. In contrast, the mitochondrial fusion protein mitofusin 1 showed an opposite trend. Moreover, the expression of dynamin-1-like protein and mitofusin 1 was significantly associated with the disease-free survival of hepatocellular carcinoma patients. In addition, our data further showed that mitochondrial fission significantly promoted the reprogramming of focal-adhesion dynamics and lamellipodia formation in hepatocellular carcinoma cells mainly by activating typical Ca2+ /CaMKII/ERK/FAK pathway. Importantly, treatment with mitochondrial division inhibitor-1 significantly decreased calcium signalling in hepatocellular carcinoma cells and had a potential treatment effect for hepatocellular carcinoma metastasis in vivo. CONCLUSIONS: Taken together, our findings demonstrate that mitochondrial fission plays a critical role in the regulation of hepatocellular carcinoma cell migration, which provides strong evidence for this process as a drug target in hepatocellular carcinoma metastasis treatment.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Dinâmica Mitocondrial , Transdução de Sinais , Animais , Carcinoma Hepatocelular/genética , Movimento Celular , Proliferação de Células , Quinase 1 de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Quinazolinonas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Receptor EphB2/metabolismo
18.
Int J Mol Med ; 41(1): 331-339, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29138798

RESUMO

Substantial evidence has indicated that Notch and bone morphogenetic protein (BMP) signaling may regulate odontoblastic differentiation. Hairy/enhancer­of­split related with YRPW motif 1 (Hey1), a downstream target gene of Notch and BMP signaling, is expressed in dental pulp tissues and has been demonstrated to be responsible for osteoblast mineralization. The aim of this study was to investigate the effects of Hey1 on odontoblast differentiation. The results of the study demonstrated that Hey1 expression in odontoblast­lineage cells (OLCs) was upregulated by stimulation of osteoblastic/odontoblastic differentiation medium containing ascorbic acid, ß­glycerol phosphate and dexamethasone. Furthermore, stable Hey1­overexpressing cells expressed higher levels of dentin sialophosphoprotein (DSPP) and exhibited higher mineralization capabilities following stimulation by differentiation medium. Furthermore, RNA interference­mediated knockdown of Hey1 downregulated the expression levels of DSPP in OLCs stimulated by differentiation medium. Taken together, the findings indicate that Hey1 may be a positive regulator of odontoblastic differentiation. The present study broadens the understanding of odontoblast differentiation and biomineralization.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/genética , Proteínas da Matriz Extracelular/genética , Odontogênese/genética , Fosfoproteínas/genética , Proteínas Repressoras/genética , Sialoglicoproteínas/genética , Animais , Ácido Ascórbico/farmacologia , Linhagem Celular , Linhagem da Célula/genética , Polpa Dentária/crescimento & desenvolvimento , Polpa Dentária/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Odontoblastos/efeitos dos fármacos , Odontoblastos/metabolismo , Transdução de Sinais/genética
19.
Antioxid Redox Signal ; 28(12): 1120-1136, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28938844

RESUMO

AIMS: Levels of the mitochondrial calcium uniporter regulator 1 (MCUR1) increases during development of hepatocellular carcinoma (HCC). However, mechanisms of how mitochondrial Ca2+ homeostasis is modulated and its function remain limited in cancers. RESULTS: MCUR1 was frequently upregulated in HCC cells to enhance the Ca2+ uptake into mitochondria in an MCU-dependent manner, which significantly facilitated cell survival by inhibiting mitochondria-dependent intrinsic apoptosis and promoting proliferation of HCC cells, and thus led to poor prognosis. In vivo assay confirmed these results, indicating that overexpressed MCUR1 notably decreased the fraction of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells and increased the positive Ki67 staining in xenograft tumors, while reduced MCUR1 expression was associated with impaired growth capacity of HCC cells in nude mice. The survival advantage conferred by MCUR1-mediated mitochondrial Ca2+ uptake was majorly caused by elevated production of mitochondrial reactive oxygen species and subsequent AKT/MDM2- induced P53 degradation, which regulated the expression level of apoptosis-related molecules and cell cycle-related molecules. Treatment of mitochondrial Ca2+-buffering protein parvalbumin remarkably inhibited the growth of HCC cells. Conclusions and Innovation: Our study provides evidence supporting a possible tumor-promoting role for MCUR1-mediated mitochondrial Ca2+ uptake and uncovers a mechanistic understanding that links change of mitochondrial Ca2+ homeostasis to cancer cell survival, which suggests a potential novel therapeutic target for HCC. Antioxid. Redox Signal. 28, 1120-1136.


Assuntos
Sinalização do Cálcio/fisiologia , Carcinoma Hepatocelular/metabolismo , Sobrevivência Celular/fisiologia , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/fisiologia , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Regulação para Cima/fisiologia
20.
J Exp Clin Cancer Res ; 36(1): 168, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29179728

RESUMO

BACKGROUND: Previous studies have indicated that tumor mitochondrial DNA (mtDNA) mutations are primarily shaped by relaxed negative selection, which is contradictory to the critical roles of mtDNA mutations in tumorigenesis. Therefore, we hypothesized that site-specific selection may influence tumor mtDNA mutations. METHODS: To test our hypothesis, we developed the largest collection of tumor mtDNA mutations to date and evaluated how natural selection shaped mtDNA mutation patterns. RESULTS: Our data demonstrated that both positive and negative selections acted on specific positions or functional units of tumor mtDNAs, although the landscape of these mutations was consistent with the relaxation of negative selection. In particular, mutation rate (mutation number in a region/region bp length) in complex V and tRNA coding regions, especially in ATP8 within complex V and in loop and variable regions within tRNA, were significantly lower than those in other regions. While the mutation rate of most codons and amino acids were consistent with the expectation under neutrality, several codons and amino acids had significantly different rates. Moreover, the mutations under selection were enriched for changes that are predicted to be deleterious, further supporting the evolutionary constraints on these regions. CONCLUSION: These results indicate the existence of site-specific selection and imply the important role of the mtDNA mutations at some specific sites in tumor development.


Assuntos
DNA Mitocondrial/genética , Mitocôndrias/genética , Neoplasias/genética , Mutação Puntual , Aminoácidos/genética , Códon/genética , DNA Mitocondrial/química , Bases de Dados Genéticas , Humanos , Mitocôndrias/química , Taxa de Mutação , Seleção Genética
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