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1.
Med Oncol ; 41(8): 191, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38954116

ABSTRACT

Zinc-finger proteins are involved in many biological processes. However, the role of Zinc-finger protein 334 (ZNF334) in cervical cancer remains unidentified. This study showed that promoter methylation of ZNF334 was responsible for its reduced expression. ZNF334 suppressed malignant biological behaviors in cervical cancer. Notably, ZNF334 reversed the EMT process both in vitro and in vivo. RNA-seq coupled with bioinformatics analysis caught P3H3 which is upregulated by ZNF334. Dual-luciferase reporter and Chromatin immunoprecipitation assays illustrated that ZNF334 directly regulate P3H3. Knockdown of P3H3 attenuated the reversal of EMT induced by ZNF334. Additionally, ZNF334 overexpression sensitized cervical cancer cells to the cytotoxic effects of paclitaxel, cyclosporine and sunitinib. In conclusions, this study illustrated that DNA methylation-based silencing ZNF334 played a vital role in cervical cancer, by regulating P3H3 in turn affects EMT. ZNF334 has the potential to become a novel diagnostic biomarker and a potential treatment target for cervical cancer.


Subject(s)
DNA Methylation , Epithelial-Mesenchymal Transition , Uterine Cervical Neoplasms , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/metabolism , Humans , Female , Epithelial-Mesenchymal Transition/genetics , Cell Line, Tumor , Animals , Mice , Gene Expression Regulation, Neoplastic , Transcription Factors/genetics , Transcription Factors/metabolism , Mice, Nude , Promoter Regions, Genetic/genetics , Histones/metabolism , Histones/genetics , Mice, Inbred BALB C
2.
Cell Signal ; 120: 111197, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38697447

ABSTRACT

OBJECTIVES: The clinical T1 stage solid lung cancer with metastasis is a serious threat to human life and health. In this study, we performed RNA sequencing on T1 advanced-stage lung cancer and adjacent tissues to identify a novel biomarker and explore its roles in lung cancer. METHODS: Quantitative reversed-transcription PCR, reverse transcription PCR and Western blot, MSP and Methtarget were utilized to evaluate FIBIN expression levels at both the transcriptional and protein levels as well as its methylation status. Differential target protein was evaluated for relative and absolute quantitation by isobaric tags. Co-IP was performed to detect the interactions between target protein. Precise location and expression levels of target proteins were revealed by immunofluorescence staining and component protein extraction using specific kits, respectively. RESULTS: We reported that FIBIN was frequently silenced due to promoter hypermethylation in lung cancer. Additionally, both in vitro and in vivo experiments confirmed the significant anti-proliferation and anti-metastasis capabilities of FIBIN. Mechanistically, FIBIN decreased the nuclear accumulation of ß-catenin by reducing the binding activity of GSK3ß with ANXA2 while promoting interaction between GSK3ß and ß-catenin. CONCLUSION: Our findings firstly identify FIBIN is a tumor suppressor, frequently silenced due to promoter hypermethylation. FIBIN may serve as a predictive biomarker for progression or metastasis among early-stage lung cancer patients.


Subject(s)
Annexin A2 , Carcinoma, Non-Small-Cell Lung , DNA Methylation , Gene Expression Regulation, Neoplastic , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/pathology , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Annexin A2/metabolism , Annexin A2/genetics , Animals , Mice , Cell Line, Tumor , Cell Proliferation , beta Catenin/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Mice, Nude , Neoplasm Metastasis , Biomarkers, Tumor/metabolism , Biomarkers, Tumor/genetics , Male , Promoter Regions, Genetic/genetics , Female , Mice, Inbred BALB C , A549 Cells , Cell Movement
3.
Cancer Med ; 12(2): 1102-1113, 2023 01.
Article in English | MEDLINE | ID: mdl-35852473

ABSTRACT

BACKGROUND: To explore the prognosis predicting ability of the combined factors, Epstein-Barr virus DNA change level (EBVCL) and tumor volume reduction ratio (TVRR) after inductive chemotherapy (IC), in locally advanced nasopharyngeal carcinoma (LANPC). METHODS: From 2010 to 2018, 299 LANPC patients were included in this retrospective study. Receiver operating characteristic (ROC) curve analysis was performed to acquire the best critical values. According to the best critical values of EBVCL and TVRR, patients were stratified into low- and high-risk groups. Kaplan-Meier and ROC curve analyses were utilized to verify the prognostic ability of the new predictor (EBVCL+TVRR). The prognostic values among EBVCL+TVRR, EBVCL, TVRR, TNM stage, and the RECIST 1.1 criteria were compared by ROC curve. The primary end points were overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional failure-free survival (LRFFS). RESULTS: ROC curve analyses of TVRR on three-year survival showed the best critical values of TVRR was 32.72% for OS, 30.21% for PFS and LRFFS, 29.87% for DMFS. The best critical value of EBVCL was 127 copies/ml for OS, and 87.7 copies/ml for PFS, DMFS, and LRFFS. The three-year OS, PFS, DMFS, and LRFFS for low- and high-risk groups were 97.7% versus 78.3% (hazard ratio [HR] = 0.2398; 95% confidence interval [CI]: 0.1277-0.4502; p < 0.0001), 91.1% versus 60.9% (HR = 0.3294; 95% CI: 0.2050-0.5292; p < 0.0001), 94.2% versus 68.7% (HR = 0.2413; 95% CI: 0.1284-0.4535; p < 0.0001) and 97.8% versus 77.9% (HR = 0.3078; 95% CI: 0.1700-0.5573; p = 0.0001), respectively. The maximal area under ROC curve of EBVCL+TVRR, EBVCL, TVRR, TNM stage, and RECIST 1.1 criteria for three-year OS was 0.829, 0.750, 0.711, 0.555, and 0.605, respectively. CONCLUSION: The new-developed indicator (EBVCL+TVRR) could better predict the LANPC patient's survival after IC compared with TNM stage system or RECIST 1.1 criteria.


Subject(s)
Carcinoma , Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/pathology , Prognosis , Herpesvirus 4, Human/genetics , Epstein-Barr Virus Infections/complications , Retrospective Studies , Tumor Burden , Nasopharyngeal Neoplasms/pathology , DNA, Viral , Carcinoma/drug therapy
5.
Front Oncol ; 12: 809304, 2022.
Article in English | MEDLINE | ID: mdl-35198442

ABSTRACT

Though single tumor immunotherapy and radiotherapy have significantly improved the survival rate of tumor patients, there are certain limitations in overcoming tumor metastasis, recurrence, and reducing side effects. Therefore, it is urgent to explore new tumor treatment methods. The new combination of radiotherapy and immunotherapy shows promise in improving therapeutic efficacy and reducing recurrence by enhancing the ability of the immune system to recognize and eradicate tumor cells, to overcome tumor immune tolerance mechanisms. Nanomaterials, as new drug-delivery-system materials of the 21st century, can maintain the activity of drugs, improve drug targeting, and reduce side effects in tumor immunotherapy. Additionally, nanomaterials, as radiosensitizers, have shown great potential in tumor radiotherapy due to their unique properties, such as light, heat, electromagnetic effects. Here, we review the mechanisms of tumor immunotherapy and radiotherapy and the synergy of radiotherapy with multiple types of immunotherapies, including immune checkpoint inhibitors (ICIs), tumor vaccines, adoptive cell therapy, and cytokine therapy. Finally, we propose the potential for nanomaterials in tumor radiotherapy and immunotherapy.

6.
Front Oncol ; 11: 698773, 2021.
Article in English | MEDLINE | ID: mdl-34490095

ABSTRACT

During the procedure of radiotherapy for superficial tumors, the key to treatment is to ensure that the skin surface receives an adequate radiation dose. However, due to the presence of the built-up effect of high-energy rays, equivalent tissue compensators (boluses) with appropriate thickness should be placed on the skin surface to increase the target radiation dose. Traditional boluses do not usually fit the skin perfectly. Wet gauze is variable in thickness day to day which results in air gaps between the skin and the bolus. These unwanted but avoidable air gaps lead to a decrease of the radiation dose in the target area and can have a poor effect on the outcome. Three-dimensional (3D) printing, a new rising technology named "additive manufacturing" (AM), could create physical models with specific shapes from digital information by using special materials. It has been favored in many fields because of its advantages, including less waste, low-cost, and individualized design. It is not an exception in the field of radiotherapy, personalized boluses made through 3D printing technology also make up for a number of shortcomings of the traditional commercial bolus. Therefore, an increasing number of researchers have tried to use 3D-printed boluses for clinical applications rather than commercial boluses. Here, we review the 3D-printed bolus's material selection and production process, its clinical applications, and potential radioactive dermatitis. Finally, we discuss some of the challenges that still need to be addressed with the 3D-printed boluses.

7.
BMC Cancer ; 21(1): 327, 2021 Mar 30.
Article in English | MEDLINE | ID: mdl-33785010

ABSTRACT

BACKGROUND: To compare the prognostic value of 7th and 8th editions of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system for patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy and simultaneous integrated boost- intensity-modulated radiation therapy (SIB-IMRT). METHODS: Patients with NPC (n = 300) who received SIB-IMRT were included. Survival by T-classification, N-classification, and stage group of each staging system was assessed. RESULTS: For T-classification, nonsignificant difference was observed between T1 and T3 and between T2 and T3 disease (P = 0.066 and 0.106, respectively) for overall survival (OS) in the 7th staging system, whereas all these differences were significant in the 8th staging system (all P < 0.05). The survival curves for disease-free survival (DFS) and locoregional recurrence-free survival (LRRFS) in both staging systems were similar, except for the comparison of T2 and T4 disease for LRRFS (P = 0.070 for 7th edition; P = 0.011 for 8th edition). For N-classification, significant differences were observed between N2 and N3 diseases after revision (P = 0.046 and P = 0.043 for OS and DFS, respectively). For staging system, no significant difference was observed between IVA and IVB of 7th edition. CONCLUSION: The 8th AJCC staging system appeared to have superior prognosis value in the SIB-IMRT era compared with the 7th edition.


Subject(s)
Nasopharyngeal Carcinoma/epidemiology , Nasopharyngeal Carcinoma/radiotherapy , Radiotherapy, Intensity-Modulated/methods , Female , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis
8.
Oral Oncol ; 111: 104924, 2020 12.
Article in English | MEDLINE | ID: mdl-32736209

ABSTRACT

PURPOSE: To compare the prognostic value of the sum volumetric regression ratio (SVRR) of the primary tumour and metastatic lymph nodes with treatment response based on RECIST 1.1 criteria after induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: A total of 117 stage III-IVA NPC patients treated with induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) were retrospectively reviewed. The SVRR and the treatment response based on RECIST 1.1 were measured using contrast-enhanced computed tomography (CT) localisations before and after induction chemotherapy. The receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff point of the SVRR and compare the prognostic value of the SVRR and RECIST 1.1criteria. RESULTS: The optimal cutoff points of SVRR for progression-free survival (PFS), locoregional failure-free survival (LRFFS) and distant metastasis-free survival (DMFS) were all 25.15%, while for overall survival (OS) it was 16.63%. The area under the ROC curve (AUC) of optimal cutoff points of SVRR was superior than that of RECIST 1.1 for PFS (AUC: 0.716 vs. 0.578; P = 0.0022), LRFFS (AUC: 0.700 vs. 0.574; P = 0.0080) and DMFS (AUC: 0.736 vs. 0.606; P = 0.0053), respectively. The 3-year PFS, DMFS and OS rates for SVRR less than vs. greater than or equal to the cutoff points were 55.8% vs. 92.2% (P < 0.001, hazard ratio (HR): 0.209, 95% confidence interval (CI): 0.091-0.480), 59.7% vs. 96.7% (P < 0.001, HR: 0.120, 95% CI: 0.043-0.336) and 66.7% vs. 98.1% (P < 0.001, HR: 0.069, 95% CI: 0.014-0.342), while the responses [stable disease (SD), partial response (PR)] based on RECIST 1.1 were not significantly associated with 3-year survival rates. Multivariate analysis indicated that SVRR was an independent prognostic factor for PFS, DMFS and OS (all P < 0.05). CONCLUSIONS: The sum volumetric regression ratio and response based on RECIST 1.1 were related to the prognosis in locoregionally advanced NPC after induction chemotherapy. Sum volumetric regression ratio is an independent outcome predictor for survival in locoregionally advanced NPC, playing a better prognostic role than RECIST 1.1.


Subject(s)
Chemoradiotherapy , Induction Chemotherapy/methods , Nasopharyngeal Carcinoma/drug therapy , Nasopharyngeal Neoplasms/drug therapy , Response Evaluation Criteria in Solid Tumors , Tumor Burden/drug effects , Contrast Media , Female , Humans , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis , Male , Middle Aged , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Carcinoma/radiotherapy , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/radiotherapy , Neoplasm Staging , Prognosis , Progression-Free Survival , ROC Curve , Radiotherapy, Intensity-Modulated , Retrospective Studies , Survival Rate , Tomography, X-Ray Computed/methods , Treatment Outcome , Tumor Burden/radiation effects
9.
Clin Epigenetics ; 11(1): 184, 2019 12 04.
Article in English | MEDLINE | ID: mdl-31801619

ABSTRACT

BACKGROUND: Recent studies suggested that ZMYND10 is a potential tumor suppressor gene in multiple tumor types. However, the mechanism by which ZMYND10 inhibits breast cancer remains unclear. Here, we investigated the role and mechanism of ZMYND10 in breast cancer inhibition. RESULTS: ZMYND10 was dramatically reduced in multiple breast cancer cell lines and tissues, which was associated with promoter hypermethylation. Ectopic expression of ZMYND10 in silenced breast cancer cells induced cell apoptosis while suppressed cell growth, cell migration and invasion in vitro, and xenograft tumor growth in vivo. Furthermore, molecular mechanism studies indicated that ZMYND10 enhances expression of miR145-5p, which suppresses the expression of NEDD9 protein through directly targeting the 3'-untranslated region of NEDD9 mRNA. CONCLUSIONS: Results from this study show that ZMYND10 suppresses breast cancer tumorigenicity by inhibiting the miR145-5p/NEDD9 signaling pathway. This novel discovered signaling pathway may be a valid target for small molecules that might help to develop new therapies to better inhibit the breast cancer metastasis.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Breast Neoplasms/pathology , Cytoskeletal Proteins/genetics , DNA Methylation , Down-Regulation , MicroRNAs/genetics , Animals , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Movement , Cell Proliferation , Epigenesis, Genetic , Female , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells , Mice , Neoplasm Invasiveness , Neoplasm Transplantation , Promoter Regions, Genetic
10.
Clin Epigenetics ; 10(1): 103, 2018 08 03.
Article in English | MEDLINE | ID: mdl-30075814

ABSTRACT

BACKGROUND: TET1 is a tumor suppressor gene (TSG) that codes for ten-eleven translocation methyl cytosine dioxygenase1 (TET1) catalyzing the conversion of 5-methylcytosine to 5-hydroxy methyl cytosine as a first step of TSG demethylation. Its hypermethylation has been associated with cancer pathogenesis. However, whether TET1 plays any role in nasopharyngeal carcinoma (NPC) remains unclear. This study investigated the expression and methylation of TET1 in NPC and confirmed its role and mechanism as a TSG. RESULTS: TET1 expression was downregulated in NPC tissues compared with nasal septum deviation tissues. Demethylation of TET1 in HONE1 and HNE1 cells restored its expression with downregulated methylation, implying that TET1 was silenced by promoter hypermethylation. Ectopic expression of TET1 suppressed the growth of NPC cells, induced apoptosis, arrested cell division in G0/G1 phase, and inhibited cell migration and invasion, confirming TET1 TSG activity. TET1 decreased the expression of nuclear ß-catenin and downstream target genes. Furthermore, TET1 could cause Wnt antagonists (DACT2, SFRP2) promoter demethylation and restore its expression in NPC cells. CONCLUSIONS: Collectively, we conclude that TET1 exerts its anti-tumor functions in NPC cells by suppressing Wnt/ß-catenin signaling via demethylation of Wnt antagonists (DACT2 and SFRP2).


Subject(s)
Carrier Proteins/genetics , Membrane Proteins/genetics , Mixed Function Oxygenases/genetics , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Neoplasms/genetics , Neoplasm Proteins/genetics , Proto-Oncogene Proteins/genetics , Wnt Signaling Pathway , Adaptor Proteins, Signal Transducing , Aged , Apoptosis , Cell Cycle , Cell Line, Tumor , Cell Movement , DNA Methylation , Down-Regulation , Epigenesis, Genetic , Epithelial-Mesenchymal Transition , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Middle Aged , Promoter Regions, Genetic , Sequence Analysis, DNA
11.
J Cell Mol Med ; 22(2): 1257-1271, 2018 02.
Article in English | MEDLINE | ID: mdl-29193730

ABSTRACT

Chromosome region 3p12-14 is an important tumour suppressor gene (TSG) locus for multiple cancers. ADAMTS9, a member of the metalloprotease large family, has been identified as a candidate 3p14.2 TSG inactivated by aberrant promoter CpG methylation in several carcinomas, but little known about its expression and function in breast cancer. In this report, ADAMTS9 expression and methylation was analysed in breast cancer cell lines and tissue samples. ADAMTS9 RNA was significantly down-regulated in breast cancer cell lines (6/8). After treating the cells with demethylation agent Aza and TSA, ADAMTS9 expression was dramatically increased. Bisulphite genomic sequencing and methylation-specific PCR detected promoter methylation, which was associated with decreased ADAMTS9 expression. Hypermethylation was also detected in 130/219 (59.4%) of primary tumours but only in 4.5% (2/44) of paired surgical margin tissues. Ectopic expression of ADAMTS9 in tumor cells induced significant growth suppression, cell cycle arrest at the G0/G1 phase, enhanced apoptosis and reduced cell migration and invasion. Conditioned culture medium from ADAMTS9-transfected BT549 cells markedly disrupted tube formation ability of human umbilical vein endothelial cell (HUVEC) in Matrigel. Furthermore, ADAMTS9 inhibited AKT signaling and its downstream targets (MDM2, p53, p21, p27, E-cadherin, VIM, SNAIL, VEGFA, NFκB-p65 and MMP2). In addition, we demonstrated, for the first time, that ADAMTS9 inhibits AKT signaling, through suppressing its upstream activators EGFR and TGFß1/TßR(I/II) in breast cancer cells. Our results suggest that ADAMTS9 is a TSG epigenetically inactivated in breast cancer, which functions through blocking EGFR- and TGFß1/TßR(I/II)-activated AKT signaling.


Subject(s)
ADAMTS9 Protein/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Chromosomes, Human, Pair 3/metabolism , CpG Islands/genetics , DNA Methylation/genetics , Promoter Regions, Genetic , ADAMTS9 Protein/genetics , Adult , Apoptosis/genetics , Breast Neoplasms/blood supply , Cell Cycle Checkpoints/genetics , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Epithelial-Mesenchymal Transition/genetics , ErbB Receptors/metabolism , Female , Gene Expression Regulation, Neoplastic , Humans , Neoplasm Invasiveness , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/pathology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Transforming Growth Factor beta/metabolism , Tumor Stem Cell Assay
12.
Int J Oncol ; 51(3): 801-811, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28677721

ABSTRACT

The transcription factor, zinc-finger protein 545 (ZNF545), that belongs to the Kruppel-associated box zinc-finger protein (KRAB-ZFP) family, acts as a tumor suppressor and is inactivated by promoter methylation in cancers such as nasopharyngeal carcinoma, breast cancer, and gastric cancer, but its role in colorectal cancer (CRC) is unknown. The purpose of this study was to characterize the ZNF545 expression, methylation status, biological function, and related molecular mechanisms in CRC. The results showed that ZNF545 was expressed in adult normal colorectal tissues, but downregulated or silenced in CRC cell lines, and this mechanism was reversed by demethylation treatment with 5-aza-2'-deoxycytidine and trichostatin A. The results also showed that the expression of ZNF545 in primary CRC tissues was significantly downregulated compared to adjacent tissues (p<0.05). Overexpression of ZNF545 caused CRC cell cycle arrest and apoptosis, suppressed cell proliferation, and suppressed colony formation and migration in vitro, showing that ZNF545 can function as a tumor suppressor. This function was also shown in nude mice. Furthermore, Wnt/ß­catenin, phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT), and mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) signaling pathways participated in the regulation of ZNF545 in CRC cells. Together, the results suggested that ZNF545 functions as a tumor suppressor in CRC and is frequently inactivated by promoter methylation.


Subject(s)
Cell Proliferation/genetics , Colorectal Neoplasms/genetics , DNA Methylation/genetics , Nuclear Proteins/genetics , Animals , Apoptosis/genetics , Cell Cycle Checkpoints/genetics , Colorectal Neoplasms/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , MAP Kinase Signaling System/genetics , Mice , Promoter Regions, Genetic , Wnt Signaling Pathway/genetics , Xenograft Model Antitumor Assays
13.
Oncotarget ; 8(24): 39443-39459, 2017 Jun 13.
Article in English | MEDLINE | ID: mdl-28467796

ABSTRACT

Dickkopf-related protein 2 (DKK2) is one of the antagonists of Wnt/ß-catenin signaling, with its downregulation reported in multiple cancers. However, how DKK2 contributes to breast tumorigenesis remains unclear. We examined its expression and promoter methylation in 10 breast tumor cell lines, 98 primary tumors, and 21 normal breast tissues. Compared with normal tissues, DKK2 was frequently silenced in breast cell lines (7/8). DKK2 promoter methylation was detected in 77.8% of cell lines and 86.7% of breast tumors; while rarely detected in normal breast tissues (19%), indicating common DKK2 methylation in breast cancer. Ectopic expression of DKK2 changed breast tumor cell morphology, inhibited cell proliferation and colony formation by inducing G0/G1 cell cycle arrest and apoptosis, and suppressed tumor cell migration by reversing epithelial-mesenchymal transition (EMT) and downregulating stem cell markers. Moreover, restored expression of DKK2 in MCF7 cells disrupted the microtube formation of human umbilical vein endothelial cells on Matrigel®. In vivo, the growth of MDA-MB-231 cells in nude mice was markedly decreased after stable expression of DKK2. DKK2 suppressed canonical Wnt/ß-catenin signaling by inhibiting ß-catenin activity with decreased active ß-catenin protein. Thus, our findings demonstrate that DKK2 functions as a tumor suppressor through inhibiting cell proliferation and inducing apoptosis via regulating Wnt signaling during breast tumorigenesis.


Subject(s)
Apoptosis/genetics , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , DNA Methylation , G1 Phase Cell Cycle Checkpoints/genetics , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Wnt Signaling Pathway , Adult , Animals , Biomarkers, Tumor , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Disease Models, Animal , Ectopic Gene Expression , Female , Gene Expression Regulation, Neoplastic , Humans , Mice , Middle Aged , Neoplasm Grading , Neoplasm Metastasis , Neoplasm Staging , Neovascularization, Pathologic/genetics , Promoter Regions, Genetic , Tumor Stem Cell Assay , Young Adult
14.
Cell Physiol Biochem ; 41(5): 1709-1724, 2017.
Article in English | MEDLINE | ID: mdl-28365691

ABSTRACT

BACKGROUND/AIMS: Aberrant activation of the Wnt/ß-catenin signaling pathway plays a key role in the pathogenesis of multiple tumors including digestive cancers. Recent studies have reported that Dickkopf-related protein 2 (DKK2) is epigenetically inactivated in numerous types of cancers and that its gene products exhibit tumor-suppressive properties. However, the biological functions and underlying molecular mechanisms of DKK2 in colon carcinoma remains obscure. METHODS: We examined the expression of DKK2 in colon tumor cell lines by RT-PCR and its promoter methylation status in colon tumor cell lines and primary tumors by methylation-specific PCR (MSP). Ectopic expression of DKK2 was measured by RT-PCR prior to the other experiments. To investigate the function of DKK2, we assayed colony formation and cell proliferation, utilized flow cytometric analyses of the cell cycle and acridine orange/ethidium bromide (AO/EB) fluorescence staining for apoptosis, and examined wound healing, transwell migration and tumor growth in vivo. Western blots were used to explore the mechanisms of DKK2 in epithelial- mesenchymal transition and canonical Wnt/ß-catenin signaling. RESULTS: We show here that downregulation or silencing of DKK2 was closely associated with the hypermethylation status of its promoter and that DKK2 expression could be restored by demethylation treatment. Methylation of the DKK2 promoter was detected in nearly all tumors and tumor-adjacent tissues, but not in normal colon tissues. Ectopic expression of DKK2 in colon cell lines HCT116 and HT-29 inhibited colony formation and cell viability by inducing cell cycle G0/G1 arrest and apoptosis, and growth of stable DKK2-infected HCT116 cells in nude mice was decreased compared to controls. Furthermore, DKK2 restrained cell migration through partial reversal of epithelial-to- mesenchymal transition and also by downregulating several stem cell markers. Our data further showed that restoration of DKK2 expression resulted in downregulation of active ß-catenin and its downstream target genes. CONCLUSION: DKK2 appears to be a functional tumor suppressor regulating tumorigenesis of colorectal cancer by antagonizing Wnt/ß-catenin signaling.


Subject(s)
Colorectal Neoplasms/metabolism , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Intercellular Signaling Peptides and Proteins/biosynthesis , Neoplasm Proteins/metabolism , Wnt Signaling Pathway , beta Catenin/metabolism , Animals , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Female , Humans , Intercellular Signaling Peptides and Proteins/genetics , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Metastasis , Neoplasm Proteins/genetics , beta Catenin/genetics
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