The inflammatory cytokine interleukin-6 (IL-6) is critical for the expression of octamer-binding transcription factor 4 (OCT4), which is highly associated with early tumor recurrence and poor ...prognosis of hepatocellular carcinomas (HCC). DNA methyltransferase (DNMT) family is closely linked with OCT4 expression and drug resistance. However, the underlying mechanism regarding the interplay between DNMTs and IL-6-induced OCT4 expression and the sorafenib resistance of HCC remains largely unclear.
HCC tissue samples were used to examine the association between DNMTs/OCT4 expression levels and clinical prognosis. Serum levels of IL-6 were detected using ELISA assays (n = 144). Gain- and loss-of-function experiments were performed in cell lines and mouse xenograft models to determine the underlying mechanism in vitro and in vivo.
We demonstrate that levels of DNA methyltransferase 3 beta (DNMT3b) are significantly correlated with the OCT4 levels in HCC tissues (n = 144), and the OCT4 expression levels are positively associated with the serum IL-6 levels. Higher levels of IL-6, DNMT3b, or OCT4 predicted early HCC recurrence and poor prognosis. We show that IL-6/STAT3 activation increases DNMT3b/1 and OCT4 in HCC. Activated phospho-STAT3 (STAT-Y640F) significantly increased DNMT3b/OCT4, while dominant negative phospho-STAT3 (STAT-Y705F) was suppressive. Inhibiting DNMT3b with RNA interference or nanaomycin A (a selective DNMT3b inhibitor) effectively suppressed the IL-6 or STAT-Y640F-induced increase of DNMT3b-OCT4 and ALDH activity in vitro and in vivo. The fact that OCT4 regulates the DNMT1 expressions were further demonstrated either by OCT4 forced expression or DNMT1 silence. Additionally, the DNMT3b silencing reduced the OCT4 expression in sorafenib-resistant Hep3B cells with or without IL-6 treatment. Notably, targeting DNMT3b with nanaomycin A significantly increased the cell sensitivity to sorafenib, with a synergistic combination index (CI) in sorafenib-resistant Hep3B cells.
The DNMT3b plays a critical role in the IL-6-mediated OCT4 expression and the drug sensitivity of sorafenib-resistant HCC. The p-STAT3 activation increases the DNMT3b/OCT4 which confers the tumor early recurrence and poor prognosis of HCC patients. Findings from this study highlight the significance of IL-6-DNMT3b-mediated OCT4 expressions in future therapeutic target for patients expressing cancer stemness-related properties or sorafenib resistance in HCC.
Metastatic dissemination of colorectal cancer (CRC), the third most common cancer type, is responsible for CRC deaths. Understanding the transition of lymph node metastasis (LNM) from Stage II to ...Stage III is beneficial in the prognosis and intervention of CRC. In this study, a quantitative proteomic survey was conducted to investigate the LNM‐associated proteins and evaluate the clinicopathological characteristics of these target proteins in CRC. By using the LC–MS/MS iTRAQ technology, we analysed the proteomic changes between LMN II and LMN III. Fresh tumours from the CRC specimens consisting of 12 node‐negative (Stage II) and 12 node‐positive (Stage III) cases were analysed by LC–MS/MS iTRAQ proteome analysis. Subsequently, tissue microarray with immunohistochemistry staining was conducted to access the clinicopathological characteristics of these proteins in 116 paraffin‐embedded CRC samples, each for non‐LNM and LNM CRC. To study the effects of the differentially expressed proteins on the potential mechanism, Boyden chamber assay, flow cytometry and shRNA‐based assessments were conducted to examine the role of the epithelial–mesenchymal transition (EMT) and the invasiveness of CRC cells and others in vivo xenograft mouse model experiments. Forty‐eight proteins were found differentially expressed between non‐LNM and LNM CRC tissues. Protein abundances of chromogranin‐A (CHGA) and ubiquitin carboxyl‐terminal hydrolase isozyme L1 (UCHL1) were observed in node‐positive CRC (p < 0.05). Knockdown of CHGA and UCHL1 significantly regulate cancer behaviours of HCT‐116, including inhibition of cell migration, invasiveness, cell cycle G1/S arrest and reactive oxygen species (ROS) generation. Mechanistically, the CHGA and UCHL1 inactivation displayed decreased levels of UCH‐L1, chromogranin A, β‐catenin, cyclin E, twist‐1/2, vimentin, MMP‐9, N‐cadherin and PCNA through the activation of the Rho‐GTPase/AKT/NFκB pathways. Histone modification of H3K4 trimethylation of CHGA and UCHL1 promoter were increased to activate their transcription through the signalling transduction such as Rho‐GTPase, AKT and NFκB pathways. Our results indicated that UCHL1 and chromogranin A are novel regulators in CRC lymph node metastasis to potentially provide new insights into the mechanism of CRC progression and serve as biomarkers for CRC diagnosis at the metastatic stage.
CIL-102 (1-4-(furo2,3-bquinolin-4-ylamino)phenylethanone) is a well-known, major active agent of the alkaloid derivative of Camptotheca acuminata with valuable biological properties, including ...anti-tumorigenic activity. In this study, we investigated the molecular mechanisms by which CIL-102 mediated the induction of cell death, and we performed cell cycle G2/M arrest to clarify molecular changes in colorectal cancer cells (CRC). Treatment of DLD-1 cells with CIL-102 resulted in triggering the extrinsic apoptosis pathway through the activation of Fas-L, caspase-8 and the induction of Bid cleavage and cytochrome c release in a time-dependent manner. In addition, CIL-102 mediated apoptosis and G2/M arrest by phosphorylation of the Jun N-terminus kinase (JNK1/2) signaling pathway. This resulted in the expression of NFκB p50, p300 and CREB-binding protein (CBP) levels, and in the induction of p21 and GADD45 as well as the decreased association of cdc2/cyclin B. Furthermore, treatment with the JNK1/2 (SP600125), NFκB (PDTI) or the p300/CBP (C646) inhibitors abolished CIL-102-induced cell cycle G2/M arrest and reversed the association of cdc2 with cyclin B. Therefore, we demonstrated that there was an increase in the cellular levels of p21 and GADD45 by CIL-102 reduction in cell viability and cell cycle arrest via the activation of the JNK1/2, NFκB p50, p300 and CBP signaling modules. Collectively, our results demonstrated that CIL-102 induced cell cycle arrest and apoptosis of colon cancer cells by upregulating p21 and GADD45 expression and by activating JNK1/2, NFκB p50 and p300 to provide a new mechanism for CIL-102 treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background/Aims: Colorectal cancer (CRC) is the third most common type of cancer and the second leading cause of cancer-related deaths worldwide. PRDXs are antioxidant enzymes that play an important ...role in cell differentiation, proliferation and apoptosis and have diverse functions in malignancy development. However, the mechanism of aberrant overexpression of PRDX6 in CRC remains unclear. Methods: Boyden chamber assay, flow cytometry and a lentiviral shRNA targeting PRDX6 and transient transfection with pCMV-6-PRDX6 plasmid were used to examine the role of PRDX6 in the proliferation capacity and invasiveness of CRC cells. Immunohistochemistry (IHC) with tissue array containing 40 paraffin- embedded CRC tissue specimens and Western blot assays were used to detect target proteins. Results: PRDX6 was significantly up-expressed in different comparisons of metastasis of colorectal adenomas in node-positive CRC (P = 0.03). In in vitro HCT-116, PRDX6 silencing markedly suppressed CRC cell migration and invasiveness while also inducing cell cycle arrest as well as the generation of reactive oxygen species (ROS); specific overexpression of PRDX6 had the opposite effect. Mechanistically, the PRDX6 inactivation displayed decreased levels of PRDX6, N-cadherin, β-catenin, Vimentin, Slug, Snail and Twist-1 through the activation of the PI3K/ AKT/p38/p50 pathways, but they were also significantly inhibited by PRDX6 transfectants. There was also increased transcriptional activation of dimethylation of histone H3 lysine 4 (H3K4me3) of PRDX6 promoter via the activation of the PI3K/Akt/NFkB pathways. Conclusion: Our findings demonstrated that PRDX6 expression plays a characteristic growth-promoting role in CRC metastasis. This study suggests that PRDX6 may serve as a biomarker of node-positive status and may have a role as an important endogenous regulator of cancer cell tumorigenicity in CRC. PRDX6 may also be an effective therapeutic target.
OBJECTIVE:A systematic review on the reproducibility of ambulatory blood pressure measurements (ABPM) has not yet been conducted. This meta-analysis compared 24-h/daytime/night-time SBP and DBP mean ...values and SBP/DBP nocturnal dipping status from ABPMs in participants with or without hypertension.
METHODS:Ovid MEDLINE, EMBASE, and CINAHL Complete databases were searched for articles published before 3 May 2019. Eligible studies reporting a 24-h ABPM repeated at least once within 1 month were included. The mean daytime/night-time/24-h BP values, percentage of nocturnal dipping, and proportion of nondippers were compared between the first and second day of measurements, and the proportion of participants with inconsistent dipping status were estimated using a random effect model.
RESULTS:Population-based analysis found a 0–1.1 mmHg difference between the first and second ABPM for 24-h/daytime/night-time SBP and DBP and 0–0.5% for percentage of SBP/DBP nocturnal dipping. The proportion of non-dippers was not different between the first and second ABPM. Intra-individual analysis found that the 95% limit of agreements (LOA) for SBP/DBP were wide and the 95% LOA for daytime SBP, common reference to diagnose hypertension, ranged −16.7 to 18.4 mmHg. Similarly, 32% of participants had inconsistent nocturnal dipping status.
CONCLUSION:ABPM had excellent reproducibility at the population level, favouring its application for research purposes; but reproducibility of intra-individual BP values and dipping status from a 24-h ABPM was limited. The available evidence was limited by the lack of high-quality studies and lack of studies in non-Western populations.
Background/Aims: A combination of fluorescence two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry approach was ...used to search for potential markers for prognosis and intervention of colorectal cancer (CRC) at different stages of lymph node metastasis (LMN). This quantitative proteomic survey aimed to investigate the LNM-associated proteins and evaluate the clinicopathological characteristics of these target proteins in CRC from stage I to stage IV. Methods: Sixteen CRC cases were categorized into paired non-LNM and LNM groups, and two-dimensional difference gel electrophoresis and MS proteome analysis were performed. Differential protein expression between non-LNM and LNM CRC was further validated in a tissue microarray, including 40 paraffin-embedded samples by immunohistochemistry staining. Moreover, a Boyden chamber assay, flow cytometry, and shRNA were used to examine the epithelial–mesenchymal transition and mechanism invasiveness of the differentially expressed proteins in DLD-1 cells and in vivo xenograft mouse model. Results: Eighteen differentially expressed proteins were found between non-LNM and LNM CRC tissues. Among them, protein levels of Gelsolin (GSN) and peroxiredoxin 4 (PRDX4) were abundant in node-positive CRC. Downregulation of GSN and PRDX4 markedly suppressed migration and invasiveness and also induced cell cycle G1/S arrest in DLD-1. Mechanistically, the EGFR/RhoA/PKCα/ERK pathways are critical for transcriptional activation of histone modification of H3 lysine 4 trimethylation (H3K4me3) of GSN and PRDX4 promoters, resulting in upregulation of GSN, PRDX4, Twist-1/2, cyclinD1, proliferating cell-nuclear antigen, β-catenin, N-cadherin, and matrix metalloprotein-9. Conclusions: GSN and PRDX4 are novel regulators in CRC lymph node metastasis to potentially provide new insights into the mechanism of CRC progression and serve as a biomarker for CRC diagnosis at the metastatic stage.
Somatic mutations of MET gene are emerging as important driver mutations for lung cancers. To identify the common clinicopathological features of MET exon 14 skipping mutations and amplification and ...clarify whether the two MET gene alterations cause protein overexpression were investigated using 196 lung cancer samples of Taiwan through real time-qPCR/sequencing, fluorescence in situ hybridization, and immunohistochemistry. The two MET gene alterations are both present in low frequency, ~1%, in the studied lung cancer population of Taiwan. MET exon 14 skipping mutations were identified from two early-stage patients, who were both relatively advanced in age, and did not carry other driver mutations. One was an adenocarcinoma and the other was a rare carcinosarcoma. Three gene amplifications cases were identified. Neither of the two MET gene alterations would lead to protein overexpression; hence, direct detection in nucleic acid level would be a preferred and straightforward solution for the identification of skipping mutations. The presence of MET exon 14 mutations in minor histological types of lung cancers urge to extend screening scope of this mutation in lung cancer and treatment response evaluation in clinical trials. These would be important next steps for the success of MET target therapy in clinical practice.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Argininosuccinate synthetase 1 (ASS1) is a rate‐limited enzyme in arginine biosynthesis. The oncogenic potential of ASS1 in terms of prognosis and cancer metastasis in arginine prototrophic gastric ...cancer (GC) remains unclear at present. We identify differentially expressed proteins in microdissected GC tumor cells relative to adjacent nontumor epithelia by isobaric mass tag for relative and absolute quantitation proteomics analysis. GC cells with stable expression or depletion of ASS1 were further analyzed to identify downstream molecules. We investigated their effects on chemoresistance and cell invasion in the presence or absence of arginine. ASS1 was highly expressed in GC and positively correlated with GC aggressiveness and poor outcome. Depletion of ASS1 led to inhibition of tumor growth and decreased cell invasion via induction of autophagy‐lysosome machinery, resulting in degradation of active β‐catenin, Snail, and Twist. Ectopic expression of ASS1 in GC cells reversed these effects and protected cancer cells from chemotherapy drug‐induced apoptosis via activation of the AKT–mammalian target of rapamycin signaling pathway. ASS1 contributes to GC progression by enhancing aggressive potential resulting from active β‐catenin, Snail, and Twist accumulation. Our results propose that ASS1 might contribute to GC metastasis and support its utility as a prognostic predictor of GC—Tsai, C.‐Y., Chi, H.‐C, Chi, L.‐M., Yang, H.‐Y., Tsai, M.‐M., Lee, K.‐F., Huang, H.‐W., Chou, L.‐F., Cheng, A.‐J., Yang, C.‐W., Wang, C.‐S., Lin, K.‐H. Argininosuccinate synthetase 1 contributes to gastric cancer invasion and progression by modulating autophagy. FASEB J. 32, 2601–2614 (2018). www.fasebj.org
The stromal cell-derived factor-1 (SDF-1)/CXC receptor 4 (CXCR4) axis plays an important role in tumor angiogenesis and invasiveness in colorectal cancer (CRC) progression. In addition, metastatic ...CRC remains one of the most difficult human malignancies to treat because of its chemoresistant behavior. However, the mechanism by which correlation occurs between CXCR4 and the clinical response of CRC to chemotherapy remains unknown. We generated chemoresistant cells with increasing doses of oxaliplatin (OXA) and 5-Fluorouracil (5FU) to develop resistance at a clinical dose. We found that the putative markers did not change in the parental cells, but HCT-116/OxR and HCT-116/5-FUR were more aggressive and had higher tumor growth (demonstrated by wound healing, chemotaxis assay, and a nude mice xenograft model) with the use of oxaliplatin. Apoptosis induced by oxaliplatin treatment was significantly decreased in HCT-116/OxR compared to the parental cells. Moreover, HCT-116/OxR cells displayed increased levels of p-gp, p-Akt p-ERK, p-IKBβ, CXCR4, and Bcl-2, but they also significantly inhibited the apoptotic pathways when compared to the parental strain. We evaluated the molecular mechanism governing the signaling pathway associated with anti-apoptosis activity and the aggressive status of chemoresistant cells. Experiments involving specific inhibitors demonstrated that the activation of the pathways associated with CXCR4, ERK1/2 mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3K)/Akt is critical to the functioning of the HCT-116/OxR and HCT-116/5-FUR characteristics of chemosensitivity. These findings elucidate the mechanism of CXCR4/PI3K/Akt downstream signaling and provide strategies to inhibit CXCR4 mediated signaling pathway in order to overcome CRC's resistance to chemotherapy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Gastric cancer (GC) is the third leading cause of cancer-related mortality worldwide and prognosis after potentially curative gastrectomy remains poor. Administration of GC-targeting molecules in ...combination with adjuvant chemo- or radiotherapy following surgical resection has been proposed as a potentially effective treatment option. Here, we have identified DOCK6, a guanine nucleotide exchange factor (GEF) for Rac1 and CDC42, as an independent biomarker for GC prognosis. Clinical findings indicate the positive correlation of higher DOCK6 expression with tumor size, depth of invasion, lymph node metastasis, vascular invasion, and pathological stage. Furthermore, elevated DOCK6 expression was significantly associated with shorter cumulative survival in both univariate and multivariate analyses. Gene ontology analysis of three independent clinical GC cohorts revealed significant involvement of DOCK6-correlated genes in the WNT/β-catenin signaling pathway. Ectopic expression of DOCK6 promoted GC cancer stem cell (CSC) characteristics and chemo- or radioresistance concomitantly through Rac1 activation. Conversely, depletion of DOCK6 suppressed CSC phenotypes and progression of GC, further demonstrating the pivotal role of DOCK6 in GC progression. Our results demonstrate a novel mechanistic link between DOCK6, Rac1, and β-catenin in GCCSC for the first time, supporting the utility of DOCK6 as an independent marker of GC.
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