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OBJECTIVE: To investigate the effects of DNA methylation and histone acetylation on the cell cycle progression and expression of tumor suppressor genes in human colon cancer (HCC) cell lines. METHODS: Three HCC cell lines (HT-29, SW1116 and Colo-320) were treated with the DNA methyl­ation inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC) or/and histone deacetylase (HDAC) inhibitors, tricho­statin A (TSA) or sodium butyrate. The methylation status of the promoter of the p16 [sup INK4A ] gene was assayed by methylation-specific PCR (MSP). The expression of p16 [sup INK4A ] and p21 [sup WAF1 ] was analyzed by RT-PCR. The cell cycle distribution was determined by flow cytometry. RESULTS: Before treatment, p16 [sup INK4A ] expression was slightly detected in the three cell lines (HT-29, SW1116 and Colo-320) and p21 [sup WAF1 ] expression was not detected in SW1116 and Colo-320 cells. The methylation level of the p16 [sup INK4A ] gene promoter significantly decreased and mRNA expression markedly increased in HT-29 cells after treatment with 1 µmol/L, but not 10 µmol/L, of 5-aza-dC for 24 h. In the SW1116 and Colo-320 cells, the expression of p16 [sup INK4A ] was markedly enhanced at 10 µmol/L or 5 µmol/L of 5-aza-dC for 24 h. However, p21 [sup WAF1 ] gene expression was not detected. Interestingly, after treatment with TSA or sodium butyrate, the transcription of p21 [sup WAF1 ] was significantly upregulated in these two cell lines. Furthermore, 5-aza-dC did not affect cell cycle distribution, but TSA or sodium butyrate blocked the cell cycle, mainly in the G[sub 1] phase. CONCLUSIONS: The expression of the p16 [sup INK4A ] gene is regulated by DNA methylation in three HCC cell lines. The expression of p21 [sup WAF1 ] gene is regulated by histone acetylation in SW1116 and Colo-320. In these two cell lines, histone hyperacetylation causes a G[sub 1] cell cycle arrest. [ABSTRACT FROM AUTHOR]

Discusses a potent cell-active allosteric inhibitor of murine DNA cytosine C methyltransferase. Determination of the inhibition potency of the single-stranded nucleic acid; Inhibition of DNA methylation activity by a single-stranded phosphorothioate derivative; Effect of inhibitor treatment of human colon cancer cells on demylation of the tumor suppressor gene.

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate, whose role in gastric carcinogenesis is controversial. The authors performed a meta-analysis and individual data pooled analysis of case-control studies that examined the association between C677T and A1298C polymorphisms (the former being associated with low folate serum levels) and gastric cancer (meta-analyses: 16 studies, 2,727 cases and 4,640 controls for C677T and seven studies, 1,223 cases and 2,015 controls for A1298C; pooled analyses: nine studies, 1,540 cases and 2,577 controls for C677T and five studies, 1,146 cases and 1,549 controls for A1298C). An increased risk was found for MTHFR 677 TT in the meta-analysis (odds ratio (OR) = 1.52, 95% confidence interval (CI): 1.31, 1.77) and pooled analysis (OR = 1.49, 95% CI: 1.14, 1.95). No association resulted for MTHFR 1298 CC (meta-OR = 0.94, 95% CI: 0.65, 1.35; pooled OR = 0.90, 95% CI: 0.69, 1.34). Results from the pooled analysis of four studies on C677T stratified according to folate levels showed an increased risk for individuals with low (OR = 2.05, 95% CI: 1.13, 3.72) versus high (OR = 0.95, 95% CI: 0.54, 1.67) folate levels. Overall, these findings support the hypothesis that folate plays a role in gastric carcinogenesis. [ABSTRACT FROM AUTHOR]

Chronic inflammation and oncogenic pathway activation are key-contributing factors in colorectal cancer pathogenesis. However, colorectal intrinsic mechanisms linking these two factors in cancer development are poorly defined. Here, we show that intestinal epithelial cell (IEC)-specific deletion of Dot1l histone methyltransferase (Dot1lΔIEC) reduced H3K79 dimethylation (H3K79me2) in IECs and inhibited intestinal tumor formation in ApcMin- and AOM-DSS-induced colorectal cancer models. IEC-Dot1l abrogation was accompanied by alleviative colorectal inflammation and reduced Wnt/β-catenin signaling activation. Mechanistically, Dot1l deficiency resulted in an increase in Foxp3+RORϒ+ regulatory T (Treg) cells and a decrease in inflammatory Th17 and Th22 cells, thereby reducing local inflammation in the intestinal tumor microenvironment. Furthermore, Dot1l deficiency caused a reduction of H3K79me2 occupancies in the promoters of the Wnt/ß-catenin signaling genes, thereby diminishing Wnt/ß-catenin oncogenic signaling pathway activation in colorectal cancer cells. Clinically, high levels of tumor H3K79me2 were detected in patients with colorectal carcinomas as compared to adenomas, and negatively correlated with RORϒ+FOXP3+ Treg cells. Altogether, we conclude that DOT1L is an intrinsic molecular node connecting chronic immune activation and oncogenic signaling pathways in colorectal cancer. Our work suggests that targeting the DOT1L pathway may control colorectal carcinogenesis. Significance: IEC-intrinsic DOT1L controls T cell subset balance and key oncogenic pathway activation, impacting colorectal carcinogenesis. [ABSTRACT FROM AUTHOR]

It is increasingly evident that long noncoding RNAs (IncRNA) have causative roles in carcinogenesis. In this study, we report findings implicating a novel IncRNA in gastric cancer, termed GAPLINC (gastric adeno-carcinoma predictive long intergenic noncoding RNA), based on the use of global microarray and in situ hybridization (ISH) analyses to identify aberrantly expressed IncRNA in human gastric cancer specimens. GAPLINC is a 924-bp-long IncRNA that is highly expressed in gastric cancer tissues. GAPLINC suppression and with gene expression profiling in gastric cancer cells revealed alterations in cell migration pathways, with CD44 expression the most highly correlated. Manipulating GAPLINC expression altered CD44 mRNA abundance and the effects of GAPLINC on cell migration and proliferation were neutralized by suppressing CD44 expression. Mechanistic investigations revealed that GAPLINC regulates CD44 as a molecular decoy for miR211-3p, a microRNA that targets both CD44 and GAPLINC. Tissue ISH analysis suggested that GAPLINC overexpression defines a subgroup of patients with gastric cancer with very poor survival. Taken together, our results identify a noncoding regulatory pathway for the CD44 oncogene, shedding new light on the basis for gastric cancer cell invasiveness. [ABSTRACT FROM AUTHOR]

The progression of colorectal carcinoma (CRC) to invasive and metastatic disease may involve localized occurrences of epithelial- mesenchymal transition (EMT). However, mechanisms of the EMT process in CRC progression are not fully understood. We previously showed that knockdown of signal transducer and activator of transcription 3 (STAT3) up-regulated E-cadherin (a key component in EMT progression) in CRC. In this study, we examined the roles of STAT3 in CRC EMT and ZEB1, an EMT inducer, in STAT3-induced down-regulation of E-cadherin. Knockdown of STAT3 significantly increased E-cadherin and decreased N-cadherin and vimentin expressions in highly invasive LoVo CRC cells. Meanwhile, overexpression of STAT3 significantly reduced E-cadherin and enhanced N-cadherin and vimentin expressions in weakly invasive SW1116 CRC cells. Activation of STAT3 significantly increased CRC cell invasiveness and resistance to apoptosis. Knockdown of STAT3 dramatically enhanced chemosensitivity of CRC cells to fluorouracil. STAT3 regulated ZEB1 expression in CRC cells, and the STAT3- induced decrease in E-cadherin and cell invasion depended on activation of ZEB1 in CRC cells. Additionally, pSTAT3Tyr-705 and ZEB1 expressions were significantly correlated with TNM (tumor, lymph node, and metastasis stages) (p < 0.01). In conclusion, STAT3 may directly mediate EMT progression and regulate ZEB1 expression in CRC. ZEB1 may participate in STAT3-induced cell invasion and E-cadherin down-regulation in CRC cells. The expressions of pSTAT3Tyr-705 and ZEB1 may be positively associated with CRC metastasis. Our data may provide potential targets to prevent and/or treat CRC invasion and metastasis. [ABSTRACT FROM AUTHOR]

Abnormalities in the STAT3 pathway are involved in the oncogenesis of several cancers. However, the mechanism by which dysregulated STAT3 signaling contributes to the progression of human colorectal cancer (CRC) has not been elucidated, nor has the role of JAK, the physiological activator of STAT3, been evaluated. To investigate the role of both JAK and STAT3 in CRC progression, we inhibited JAK with AG490 and depleted STAT3 with a SiRNA. Our results demonstrate that STAT3 and both JAK1 and 2 are involved in CRC cell growth, survival, invasion, and migration through regulation of gene expression, such as Bcl-2, p16ink4a, p21waf1/cip1, p27kip1, E-cadherin, VEGF, and MMPs. Importantly, the FAK is not required for STAT3-mediated regulation, but does function downstream of JAK. In addition, our data show that proteasome-mediated proteolysis promotes dephosphorylation of the JAK2, and consequently, negatively regulates STAT3 signaling in CRC. Moreover, immunohistochemical staining reveals that nuclear staining of phospho-STAT3 mostly presents in adenomas and adenocarcinomas, and a positive correlation is found between phospho-JAK2 immunoreactivity and the differentiation of colorectal adenocarcinomas. Therefore, our findings illustrate the biologic significance of JAK1, 2/STAT3 signaling in CRC progression and provide novel evidence that the JAK/STAT3 pathway may be a new potential target for therapy of CRC. [ABSTRACT FROM AUTHOR]

The extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) pathway is a critical intermediary for cell proliferation, differentiation, and survival. In the human colon cancer cell line SW1116, treatment with the DNA methyltransferase 1 (DNMT1) inhibitor 5-aza-2′-deoxycytidine (5-aza-dC) or the ERK-MAPK inhibitors PD98059 or rottlerin, or transient transfection with the MAP/ERK kinase (MEK)1/2 small interfering RNA down-regulates DNMT1 and proliferating cell nuclear antigen levels. In this report, we found that drug treatment or small interfering RNA transfection of SW1116 cells induced promoter demethylation of the p16INK4A and p21WAF1 genes, which up-regulated their mRNA and protein expression levels. Flow cytometry revealed that rottlerin treatment induced cell cycle arrest at phase G1 (p < 0.05). Thus, the ERK-MAPK inhibitor treatment or siRNA-mediated knockdown of ERK-MAPK decreases DNA methylation via down-regulating DNMT1 expression and other unknown mediator(s) in SW1116 colon cancer cells. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical efficacy of haploid hematopoietic stem cells (haplo-HSC) combined with third-party umbilical cord blood (tpCB) transplantation in the treatment of X-linked chronic granulomatous disease (X-CGD)., Methods: The clinical data of 26 boys with X-CGD were retrospectively analyzed who were admitted to the Sixth Medical Center of PLA General Hospital between April 2014 and March 2018. All the patients were treated with haplo-HSC combined with tpCB transplantation. The median age of the patients was 3.5 years. The donor was the father in 25 cases and an aunt in 1 case. Transplantation was 5/6 HLA-matched in 9 cases, 4/6 in 12 cases, and 3/6 in 5 cases. The patients received busulfan, cyclophosphamide, fludarabine, or anti-thymocyte globulin for myeloablative preconditioning. Cyclosporine A and mycophenolate mofetil were used for prevention of acute graft-versus-host disease (aGVHD). Then the patients were treated with haploid bone marrow hematopoietic stem cells combined with tpCB transplantation on day 1 and haploid peripheral hematopoietic stem cells on day 2. The counts of median donor total nucleated cells, CD34 + cells, and CD3 + cells were 14.6×10 8 /kg, 5.86×10 6 /kg, and 2.13×10 8 /kg respectively., Results: The median time to neutrophil and platelet engraftment was 12 and 23 days after transplantation respectively. Full donor hematopoietic chimerism was observed on day 30. Twenty-five cases were from haplo-HSC and 1 was from cord blood. No primary implant failure and implant dysfunction occurred, and secondary implant failure occurred in one case. The NADPH oxidase activity returned to normal one month after transplantation. The incidence of grade I-II aGVHD and grade III-IV aGVHD was 35% and 15% respectively. Chronic GVHD (cGVHD) of the skin occurred in one case, and no progression was observed after steroid administration. During the follow-up period of 6-51 months, 25 patients survived, of whom 24 were disease-free (23 patients without cGVHD and 1 with cGVHD of the skin) and NADPH oxidase activity returned to normal; one patient developed secondary implant failure but survived; one patient died of viral interstitial pneumonia 16 months after transplantation. The 5-year event-free survival rate and overall survival rate were 81%±12% and 89%±10% respectively., Conclusions: Haplo-HSC combined with tpCB transplantation is one of the effective methods for the treatment of X-CGD in children.

Aim: To investigate the factors influencing the occurrence of gastric varioliform lesions (GVLs) and their possible link with gastric cancer., Methods: A 1:1 matched case-control study was performed to retrospectively analyze data from 1638 chronic gastritis patients who had undergone gastroscopy at one of two Chinese hospitals between 2009 and 2014. Patients with GVLs (cases) were compared to those without such lesions (controls). Endoscopic and pathological findings were recorded, along with interview information on Helicobacter pylori (H. pylori) infection, medical, drug and family histories, lifestyle and eating habits. The association between each factor and the occurrence of GVLs was estimated, and then multivariate conditional logistic regression was used to evaluate the independent factors., Results: The frequency and severity of glandular atrophy, intestinal metaplasia (IM) and low-grade intraepithelial neoplasia were significantly increased in the GVL group (P < 0.01). Overall analysis showed that H. pylori infection [3.051 (2.157, 4.317), P <0.001], allergic respiratory diseases [3.636 (2.183, 6.055), P < 0.001], work-related stress [2.019 (1.568, 2.600), P < 0.001], irregular meals [2.300 (1.462, 3.619), P < 0.001], high intake of spicy food [1.754 (1.227, 2.507), P = 0.002] and high intake of fresh fruit [0.231 (0.101, 0.529), P = 0.001] were significantly correlated with the occurrence of GVLs (positively, except for the latter). Stratified analyses indicated that pickled food consumption in patients over 50 years old [7.224 (2.360, 22.115), P = 0.001] and excessive smoking in men [2.013 (1.282, 3.163), P = 0.002] were also positively correlated, and that, for antral GVLs, vegetable consumption [0.491 (0.311, 0.776), P = 0.002] was negatively correlated., Conclusion: Seven risk factors and two protective factors are determined for GVLs, which were found to be associated with premalignant abnormalities.