The role of the retinoblastoma protein-interacting zinc finger gene 1 tumor suppressor gene in human esophageal squamous cell carcinoma cells.
ABSTRACT: The tumor suppressor protein retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) is downregulated in several types of cancer, including esophageal squamous cell carcinoma (ESCC). The present study used two in vitro methods to re-express RIZ1 in the human ESCC TE13 cell line in order to induce apoptosis. RIZ1 was re-expressed in the TE13 cells by reintroducing the gene through transfection or by removal of transcriptional repression through treatment with a DNA methyltransferase (DNMT) inhibitor. To reintroduce the gene, the open reading frame of the RIZ1 gene was inserted into the eukaryotic expression pcDNA3.1(+) vector and pcDNA3.1(+)/RIZ1 was purified and transfected into the TE13 ESCC cells. Removing transcriptional repression involved treating the TE13 cells with 5-aza-2'-deoxycytidine (5-aza-CdR), a DNMT inhibitor. RIZ1 mRNA and protein expression were determined by quantitative polymerase chain reaction (qPCR) and western blotting. The rate of apoptosis of the cells was determined by flow cytometry. A recombinant eukaryotic human RIZ1 expression plasmid, pcDNA3.1(+)/RIZ1, was constructed and confirmed by sequencing. RIZ1 mRNA and protein expression increased in pcDNA3.1(+)/RIZ1 stably transfected cells. Treatment with 5-aza-CdR for 48 and 72 h resulted in increased RIZ1 protein expression and increased the rate of apoptosis in the TE13 cells (P<0.01). In conclusion, transfection of the TE13 cells with the eukaryotic pcDNA3.1(+)/RIZ1 expression vector and reversal of transcriptional repression of RIZ1 using 5-aza-CdR demonstrate that it is possible to re-express RIZ1 in TE13 cells. Furthermore, the re-expression of RIZ1 led to an increased rate of apoptosis and this method may provide new therapeutic possibilities.
Project description:<h4>Background</h4>Uterine leiomyoma is a benign tumor with unclear pathogenesis and inaccurate treatment. This tumor exhibits altered DNA methylation related to disease progression. DNMT inhibitors as 5-aza-2'-deoxycytidine (5-aza-CdR), have been suggested to treat tumors in which DNA methylation is altered. We aimed to evaluate whether DNA methylation reversion with 5-aza-CdR reduces cell proliferation and extracellular matrix (ECM) formation in uterine leiomyoma cells to provide a potential treatment option.<h4>Methods</h4>Prospective study using uterine leiomyoma and adjacent myometrium tissues and human uterine leiomyoma primary (HULP) cells (n = 16). In tissues, gene expression was analyzed by qRT-PCR and DNMT activity by ELISA. Effects of 5-aza-CdR treatment on HULP cells were assessed by CellTiter, western blot, and qRT-PCR.<h4>Results</h4>DNMT1 gene expression was higher in uterine leiomyoma vs myometrium. Similarly, DNMT activity was greater in uterine leiomyoma and HULP cells (6.5 vs 3.8 OD/h/mg; 211.3 vs 63.7 OD/h/mg, respectively). After 5-aza-CdR treatment on HULP cells, cell viability was reduced, significantly so at 10 μM (85.3%). Treatment with 10 μM 5-aza-CdR on HULP cells significantly decreased expression of proliferation marker PCNA (FC = 0.695) and of ECM proteins (COLLAGEN I FC = 0.654; PAI-1, FC = 0.654; FIBRONECTIN FC = 0.733). 5-aza-CdR treatment also decreased expression of Wnt/β-catenin pathway final targets, including WISP1 protein expression (10 μM, FC = 0.699), c-MYC gene expression (2 μM, FC = 0.745 and 10 μM, FC = 0.728), and MMP7 gene expression (5 μM, FC = 0.520 and 10 μM, FC = 0.577).<h4>Conclusions</h4>5-aza-CdR treatment inhibits cell proliferation, ECM formation, and Wnt/β-catenin signaling pathway targets in HULP cells, suggesting that DNA methylation inhibition is a viable therapeutic target in uterine leiomyoma.
Project description:The function of human transmembrane protein 176A (TMEM176A) in cancer remains unclear. To understand the function and mechanism of TMEM176A in human esophageal cancer development, 13 esophageal cancer cell lines and 267 cases of primary esophageal squamous cell cancer (ESCC) samples were analyzed by methylation specific PCR (MSP), flow cytometry, immunohistochemistry and transfection assays. TMEM176A was highly expressed in BIC1 cells and loss of TMEM176A expression was found in TE1, TE3, TE13, KYSE140, KYSE180, KYSE410, KYSE450, KYSE520, Segl, KYSE150, YES2 and COLO680N cells. Complete methylation was detected in TE1, TE3, TE13, KYSE140, KYSE180, KYSE410, KYSE450, KYSE520, Segl, KYSE150, YES2 and COLO680N cells, while unmethylation was detected in BIC1 cells. Restoration of TMEM176A expression was induced by 5-aza-2'-deoxycytidine treatment in methylated cell lines. TMEM176A was methylated in 66.7% (178/267) of primary esophageal cancer samples, and promoter region methylation was significantly associated with tumor differentiation (p<0.001) and loss off/reduced expression of TMEM176A (p<0.05). Methylation of TMEM176A was significantly associated with poor 5-year overall survival (p < 0.05). Cox proportional hazards model analysis suggest that TMEM176A methylation is an independent prognostic factor for poor 5-years OS. TMEM176A inhibited cell invasion and migration, and induced apoptosis in esophageal cancer cells. TMEM176A suppressed esophageal cancer cell growth both in vitro and in vivo. In conclusion, TMEM176A is frequently methylated in human ESCC and the expression of TMEM176A is regulated by promoter region methylation. TMEM176A methylation may serve as a diagnostic and prognostic marker in ESCC. TMEM176A is a potential tumor suppressor in human ESCC.
Project description:Background:Genome-wide sequencing investigations have identified numerous long noncoding RNAs (lncRNAs) among mammals, many of which exhibit aberrant expression in cancers, including esophageal squamous cell carcinoma (ESCC). Herein, this study elucidates the role and mechanism by which LINC01419 regulates the DNA methylation of glutathione S-transferase pi 1 (GSTP1) in relation to ESCC progression and the sensitivity of ESCC cells to 5-fluorouracil (5-FU). Methods:LINC01419 and GSTP1 levels were quantified among 38 paired ESCC and adjacent tissue samples collected from patients with ESCC. To ascertain the contributory role of LINC01419 in the progression of ESCC and identify the interaction between LINC01419 and GSTP1 promoter methylation, LINC01419 was overexpressed or silenced, and the DNA methyltransferase inhibitor 5-Aza-CdR was treated. Results:Data from the GEO database (GSE21362) and the Cancer Genome Atlas displayed elevated levels of LINC01419 and downregulated levels of GSTP1 in the ESCC tissues and cells. The silencing of LINC01419 led to decreased proliferation, increased apoptosis, and enhanced sensitivity to 5-FU in ESCC cells. Notably, LINC01419 could bind to the promoter region of the GSTP1 gene, resulting in elevated GSTP1 methylation and reduced GSTP1 levels via the recruitment of DNA methyltransferase among ESCC cells, whereby ESCC progression was stimulated accompanied by reduced ESCC cell sensitivity to 5-FU. GSTP1 demethylation by 5-Aza-CdR was observed to reverse the effects of LINC01419 overexpression in ESCC cells and the response to 5-FU. Conclusion:Highly expressed LINC01419 in ESCC promotes GSTP1 methylation, which ultimately acts to promote the event of ESCC and diminish the sensitivity of ESCC cells to 5-FU, highlighting a novel potential strategy to improve 5-FU-based chemotherapy in ESCC.
Project description:Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive carcinomas of the gastrointestinal tract. We assessed the relevance of Slug in measuring the invasive potential of ESCC cells in vitro and in vivo in immunodeficient mice.We utilized RNA interference to knockdown Slug gene expression, and effects on survival and invasive carcinoma were evaluated using a Boyden chamber transwell assay in vitro. We evaluated the effect of Slug siRNA-transfection and Slug cDNA-transfection on E-cadherin and Bcl-2 expression in ESCC cells. A pseudometastatic model of ESCC in immunodeficient mice was used to assess the effects of Slug siRNA transfection on tumor metastasis development.The EC109 cell line was transfected with Slug-siRNA to knockdown Slug expression. The TE13 cell line was transfected with Slug-cDNA to increase Slug expression. EC109 and TE13 cell lines were tested for the expression of apoptosis-related genes bcl-2 and metastasis-related gene E-cadherin identified previously as Slug targets. Bcl-2 expression was increased and E-cadherin was decreased in Slug siRNA-transfected EC109 cells. Bcl-2 expression was increased and E-cadherin was decreased in Slug cDNA-transfected TE13 cells. Invasion of Slug siRNA-transfected EC109 cells was reduced and apoptosis was increased whereas invasion was greater in Slug cDNA-transfected cells. Animals injected with Slug siRNA-transfected EC109 cells exhibited fewer seeded nodes and demonstrated more apoptosis.Slug down-regulation promotes cell apoptosis and decreases invasion capability in vitro and in vivo. Slug inhibition may represent a novel strategy for treatment of metastatic ESCC.
Project description:The purpose of this study was to investigate whether inhibition of DNA (cytosine-5)-methyltransferase 1 (DNMT-1) alleviated ferroptosis through nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy during diabetes myocardial (DM) ischemia/reperfusion (I/R) injury (IRI). Rat DM + sham (DS), I/R, and DM + I/R (DIR), H9c2 cell high glucose (HG), hypoxia reoxygenation (H/R), and high-glucose hypoxia reoxygenation (HH/R) models were established. DNMT-1 inhibitor 5-Aza-2'-deoxycytidine (5-aza-CdR) was administered to rat and cell models. The protein level of DNMT-1, NCOA4, FTH, GPX4, Beclin-1, and P62 was detected by western blotting. Compared with normal sham (NS) group, myocardial tissue was injured in DS and I/R models. The level of DNMT-1, NCOA4, and ferroptosis was increased. Moreover, the cell injury was more serious in rat DIR or HH/R model. 5-Aza-CdR could reduce NCOA4-mediated ferritinophagy and myocardial injury in DIR and HH/R models. Moreover, the siRNA for NCOA4 could also reduce the level of ferritinophagy and cell injury in HH/R model. 5-Aza-CdR enhanced the protective effect for NCOA4-siRNA in the process of cell injury. Inhibition of DNMT-1 could reduce ferroptosis during DIR, which the NCOA4-mediated ferritinophagy might be regulated.
Project description:Esophageal cancers (ECs) are highly aggressive tumors with poor prognosis and few treatment options. This study investigated the possibility of treating esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells by inhibitors of broad and specific histone deacetylases (HDACi; SAHA, MS-275, FK228) and/or of DNMT (Azacytidine, AZA). Drug targets (HDAC1,2,3 and DNMT1) were present in non-neoplastic (HET-1A), ESCC (OE21) and EAC (OE33) cell lines. All cell lines responded to HDACi by reduced HDAC activity and increased histone acetylation as well as to AZA by up-regulation of p21. Expression of drug targets remained largely unaffected by HDACi and AZA treatment. Importantly, cell viability, apoptosis, cell cycle dynamics and DNA damage were only affected by HDACi and/or AZA in ESCC and EAC, but not the non-neoplastic cells. This was specifically seen for the combination of MS-275 and AZA, leading to enhanced cancer cell selectivity and drug efficiency. By transcriptome analyses of MS-275, AZA and MS-275/AZA treated cells, known (e.g. p21) as well as novel regulated genes significantly associated with the cellular effects post HDACi and/or AZA treatment in ESCC and EAC cells were identified. Finally, human EC tissue specimens frequently expressed the actionable drug targets HDAC1/2/3 and DNMT1. In summary, a combined HDACi (MS-275)/AZA treatment is cancer cell selective and efficient in vitro. Since the majority of ECs express the drug targets in situ, this paves the way for further investigations of HDACi/AZA treatment in esophageal cancer cells and their translation into a clinico-pathological setting. To elucidate the transcriptome response to HDAC inhibitors of normal esophageal cells and esophageal tumor cells, total RNA was isolated from non-neoplastic esophageal epithelial cells (Het1A cells) a well as from two esophageal tumor cell lines (OE21 and OE33), respectively. Cells were treated with either MS-275, Azacytidine (AZA) or in combination of both. DMSO treatment was used as control in each case. Total RNA was isolated from cells 24 h after treatment and experiments were performed in biological triplicates.
Project description:Activation-induced cytidine deaminase (AID) was originally identified as an inducer of somatic hypermutation (SHM) and class switch recombination (CSR) in immunoglobulin genes. However, AID can also cause mutations in host genes and contribute to cancer progression and drug resistance. In this study, molecular docking showed the interaction of free 5-aza-CdR and Zebularine (Zeb) with AID. However, only 5-aza-CdR-incorporated ssDNA bound to the active site of AID and inhibited AID expression through proteasomal degradation. 5-aza-CdR demonstrated cytotoxicity against AID-positive and -negative hematopoietic cancer cells. In contrast, Zeb exhibited a cytotoxic effect only in AID-negative cells due to its inability to inhibit AID expression. This differential effect might be due to the DNMT1 stabilization induced by AID, thus restricting the ability of Zeb to deplete DNMT1 and induce tumor suppressor genes (TSGs), such as p21, in AID-positive cells. Moreover, the in vivo anticancer effect of 5-aza-CdR but not Zeb in AID-positive hematopoietic cancer cells was demonstrated. The study not only displays the association of AID and DNMT1 and identifies a novel biological function of AID, but also provides novel information regarding the use of DNMT inhibitors to treat AID-positive hematopoietic cancers.
Project description:Cancer stem cells (CSCs) have been isolated from many tumors and considered as the main reason of cancer recurrence and metastasis. DNA methyltransferase 1 (DNMT1) mediates DNA methylation and plays an important role in CSCs maintenance. However, the function of DNMT1 in CSCs of esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we examined the role of DNMT1 in regulating self-renewal in CSCs of ESCC. We found a high expression of DNMT1 in both side population (SP) cells and sphere formation cells that represented as substitutes for CSCs in KYSE150 and EC109 ESCC cell lines. We performed the knockdown of DNMT1 using lentivirus-mediated RNA interference (RNAi) methods. We revealed that ablation of DNMT1 resulted in the numbers and self-renewal abilities of CSCs refrained significantly in ESCC cells. As a result of the CSCs inhibition, the malignant phenotypes such as cell proliferation, colony formation, migration and drug resistance abilities were dramatically inhibited in ESCC cells. Treatment of 5-aza-2'-deoxycytidine (5-aza-dC), a DNMT inhibitor, also resulted in the inhibition of CSCs and malignant profiles in ESCC cells. Our findings also provided the first evidence that 5-aza-dC inhibited the colony and sphere formation of CSCs. Thus, our results indicated that DNMT1 was important for the self-renewal maintenance of CSCs in ESCC, and 5-aza-dC could be a potential therapy for the CSCs of ESCC.
Project description:DNA methylation is an epigenetic mechanism establishing long-term gene silencing during development and cell commitment, which is maintained in subsequent cell generations. Aberrant DNA methylation is found at gene promoters in most cancers and can lead to silencing of tumor suppressor genes. The DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) is able to reactivate genes silenced by DNA methylation and has been shown to be a very potent epigenetic drug in several hematological malignancies. In this report, we demonstrate that 5-aza-CdR exhibits high antineoplastic activity against anaplastic large cell lymphoma (ALCL), a rare CD30 positive non-Hodgkin lymphoma of T-cell origin. Low dose treatment of ALCL cell lines and xenografted tumors causes apoptosis and cell cycle arrest in vitro and in vivo. This is also reflected in genome-wide expression analyses, where genes related to apoptosis and cell death are amongst the most affected targets of 5-aza-CdR. Furthermore, we observed demethylation and re-expression of p16(INK4A) after drug administration and senescence associated ?-galactosidase activity. Thus, our data provide evidence that 5-aza-CdR is highly efficient against ALCL and warrants further clinical evaluation for future therapeutic use.
Project description:DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2'-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.