1
|
Liu A, Li X, Hao Z, Cao J, Li H, Sun M, Zhang Z, Liang R, Zhang H. Alterations of DNA methylation and mRNA levels of CYP1A1, GSTP1, and GSTM1 in human bronchial epithelial cells induced by benzo[a]pyrene. Toxicol Ind Health 2022; 38:127-138. [PMID: 35193440 DOI: 10.1177/07482337211069233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Benzo[a]pyrene (B[a]P) is a known human carcinogen and plays a major function in the initiation of lung cancer at its first proximity. However, the underlying molecular mechanisms are less well understood. In this study, we investigated the impact of B[a]P treatment on the DNA methylation and mRNA levels of CYP1A1, GSTP1, and GSTM1 in human bronchial epithelial cells (16HBEs), and provide scientific evidence for the mechanism study on the carcinogenesis of B[a]P. We treated 16HBEs with DMSO or concentrations of B[a]P at 1, 2, and 5 mmol/L for 24 h, observed the morphological changes, determined the cell viability, DNA methylation, and mRNA levels of CYP1A1, GSTP1, and GSTM1. Compared to the DMSO controls, B[a]P treatment had significantly increased the neoplastic cell number and cell viability in 16HBEs at all three doses (1, 2, and 5 mmol/L), and had significantly reduced the CYP1A1 and GSTP1 DNA promoter methylation levels. Following B[a]P treatment, the GSTM1 promoter methylation level in 16HBEs was profoundly reduced at low dose group compared to the DMSO controls, yet it was significantly increased at both middle and high dose groups. The mRNA levels of CYP1A1, GSTP1, and GSTM1 were significantly decreased in 16HBEs following B[a]P treatment at all three doses. The findings demonstrate that B[a]P promoted cell proliferation in 16HBEs, which was possibly related to the altered DNA methylations and the inhibited mRNA levels in CYP1A1, GSTP1, and GSTM1.
Collapse
Affiliation(s)
- Aixiang Liu
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China.,Department of Health Information Management, 74648Shanxi Medical University Fenyang College, Fenyang, Shanxi, China
| | - Xin Li
- Center of Disease Control and Prevention, 442190Taiyuan Iron and Steel Co Ltd, Taiyuan, Shanxi, China
| | - Zhongsuo Hao
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Jingjing Cao
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Huan Li
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Min Sun
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Zhihong Zhang
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Ruifeng Liang
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| | - Hongmei Zhang
- Department of Environmental Health, School of Public Health, 74648Shanxi Medical University, Taiyuan, Shanxi, China
| |
Collapse
|
2
|
LEF1 silencing sensitizes colorectal cancer cells to oxaliplatin, 5-FU, and irinotecan. Biomed Pharmacother 2021; 143:112091. [PMID: 34474344 DOI: 10.1016/j.biopha.2021.112091] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022] Open
Abstract
Colorectal cancer (CRC) is the third most prevalent cancer all around the world. Chemotherapy plays an essential role in the treatment of CRC while Oxaliplatin, Irinotecan, and 5 - fluorouracil (5-FU) are the most commonly used chemotherapeutic drugs. However, chemo-resistance is a major obstacle to successful therapy. It has been shown that inhibition of Wnt signaling pathway can sensitize the cells to chemotherapy. Lymphoid enhancer factor (LEF1) is a member of TCF/LEF transcription family mediating Wnt nuclear responses. The long isoform of LEF1 is highly expressed in colorectal cancer cells compared to the normal intestinal cells, in which expression of the short isoform is dominant. We found that the downregulation of long isoforms of LEF1 makes CRC cell lines more sensitive to the effect of chemotherapeutic drugs. This sensitivity is imposed by reduced proliferation, increased apoptosis, or cell cycle arrest. Our results also demonstrated that there is a balance in the expression of long, and short isoforms of LEF1. In summary, we showed the role of LEF1 in chemo-resistance of colorectal cancer cells to Oxaliplatin, Irinotecan and 5-FU.
Collapse
|
3
|
Zhang Y, Zhang H. RNAa Induced by TATA Box-Targeting MicroRNAs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019. [PMID: 28639194 DOI: 10.1007/978-981-10-4310-9_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent studies reveal that some nuclear microRNAs (miRNA) and synthesized siRNAs target gene promoters to activate gene transcription (RNAa). Interestingly, our group identified a novel HIV-1-encoded miRNA, miR-H3, which targets specifically the core promoter TATA box of HIV-1 and activates viral gene expression. Depletion of miR-H3 significantly impaired the replication of HIV-1. miR-H3 mimics could activate viruses from CD4+ T cells isolated from patients receiving suppressive highly active antiretroviral therapy, which is very intriguing for reducing HIV-1 latent reservoir. Further study revealed that many cellular miRNAs also function like miR-H3. For instance, let-7i targets the TATA box of the interleukin-2 (IL-2) promoter and upregulates IL-2 expression in T-lymphocytes. In RNAa induced by TATA box-targeting miRNAs, Argonaute (AGO) proteins are needed, but there is no evidence for the involvement of promoter-associated transcripts or epigenetic modifications. We propose that the binding of small RNA-AGO complex to TATA box could facilitate the assembly of RNA Polymerase II transcription preinitiation complex. In addition, synthesized small RNAs targeting TATA box can also efficiently activate transcription of interested genes, such as insulin, IL-2, and c-Myc. The discovery of RNAa induced by TATA box-targeting miRNA provides an easy-to-use tool for activating gene expression.
Collapse
Affiliation(s)
- Yijun Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.,Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Hui Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China. .,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.
| |
Collapse
|
4
|
Dar SA, Kumar M. saRNAdb: Resource of Small Activating RNAs for Up-regulating the Gene Expression. J Mol Biol 2018; 430:2212-2218. [PMID: 29625201 DOI: 10.1016/j.jmb.2018.03.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/19/2018] [Accepted: 03/22/2018] [Indexed: 12/19/2022]
Abstract
RNA activation (RNAa) is the process of enhancing selective gene expression at transcriptional level using double-stranded RNAs, targeting gene promoter. These RNA molecules are usually 21 nucleotides long and termed as small activating RNAs (saRNAs). They are involved in gene regulation, epigenetics, gain-of-function studies and have potential therapeutic applications for various diseases especially cancer. RNAa is opposite to RNA interference in functionality; however, both processes share some protein machinery. There are many RNA interference centered online resources but no one for saRNAs; therefore, we developed "saRNAdb" database (http://bioinfo.imtech.res.in/manojk/sarna/). It contains 2150 manually curated saRNA entries with detailed information about their nucleotide sequences, activities, corresponding target gene, promoter and other experimental data. Besides, saRNA-promoter binding location, predicted saRNA features, tools (off-target, map) and RNAa-related proteins with their interacting partners are provided. saRNAdb is expected to assist in RNA research especially for nucleic acid-based therapeutics development.
Collapse
Affiliation(s)
- Showkat Ahmad Dar
- Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific and Industrial Research, Sector 39A, Chandigarh 160036, India
| | - Manoj Kumar
- Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific and Industrial Research, Sector 39A, Chandigarh 160036, India.
| |
Collapse
|
5
|
Zhang Y, Liu W, Chen Y, Liu J, Wu K, Su L, Zhang W, Jiang Y, Zhang X, Zhang Y, Liu C, Tao L, Liu B, Zhang H. A Cellular MicroRNA Facilitates Regulatory T Lymphocyte Development by Targeting the FOXP3 Promoter TATA-Box Motif. THE JOURNAL OF IMMUNOLOGY 2017; 200:1053-1063. [DOI: 10.4049/jimmunol.1700196] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 11/16/2017] [Indexed: 12/18/2022]
|
6
|
Li LC. Small RNA-Guided Transcriptional Gene Activation (RNAa) in Mammalian Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [DOI: 10.1007/978-981-10-4310-9_1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
7
|
Target-Recognition Mechanism and Specificity of RNA Activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [DOI: 10.1007/978-981-10-4310-9_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
8
|
Meng X, Jiang Q, Chang N, Wang X, Liu C, Xiong J, Cao H, Liang Z. Small activating RNA binds to the genomic target site in a seed-region-dependent manner. Nucleic Acids Res 2016; 44:2274-82. [PMID: 26873922 PMCID: PMC4797303 DOI: 10.1093/nar/gkw076] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 01/29/2016] [Indexed: 01/27/2023] Open
Abstract
RNA activation (RNAa) is the upregulation of gene expression by small activating RNAs (saRNAs). In order to investigate the mechanism by which saRNAs act in RNAa, we used the progesterone receptor (PR) gene as a model, established a panel of effective saRNAs and assessed the involvement of the sense and antisense strands of saRNA in RNAa. All active saRNAs had their antisense strand effectively incorporated into Ago2, whereas such consistency did not occur for the sense strand. Using a distal hotspot for saRNA targeting at 1.6-kb upstream from the PR transcription start site, we further established that gene activation mediated by saRNA depended on the complementarity of the 5' region of the antisense strand, and that such activity was largely abolished by mutations in this region of the saRNA. We found markedly reduced RNAa effects when we created mutations in the genomic target site of saRNA PR-1611, thus providing evidence that RNAa depends on the integrity of the DNA target. We further demonstrated that this saRNA bound the target site on promoter DNA. These results demonstrated that saRNAs work via an on-site mechanism by binding to target genomic DNA in a seed-region-dependent manner, reminiscent of miRNA-like target recognition.
Collapse
Affiliation(s)
- Xing Meng
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Qian Jiang
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Nannan Chang
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Xiaoxia Wang
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Chujun Liu
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Jingwei Xiong
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Huiqing Cao
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China
| | - Zicai Liang
- Institute of Molecular Medicine, Peking University, Beijing 100871, PR China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China
| |
Collapse
|
9
|
Targeting Highly Structured RNA by Cooperative Action of siRNAs and Helper Antisense Oligomers in Living Cells. PLoS One 2015; 10:e0136395. [PMID: 26308932 PMCID: PMC4556297 DOI: 10.1371/journal.pone.0136395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/03/2015] [Indexed: 12/02/2022] Open
Abstract
RNA target accessibility is one of the most important factors limiting the efficiency of RNA interference-mediated RNA degradation. However, targeting RNA viruses in their poorly accessible, highly structured regions can be advantageous because these regions are often conserved in sequence and thus less prone to viral escape. We developed an experimental strategy to attack highly structured RNA by means of pairs of specifically designed small interfering RNAs and helper antisense oligonucleotides using the 5’ untranslated region (5’UTR) of coxsackievirus B3 as a model target. In the first step, sites accessible to hybridization of complementary oligonucleotides were identified using two mapping methods with random libraries of short DNA oligomers. Subsequently, the accessibility of the mapped regions for hybridization of longer DNA 16-mers was confirmed by an RNase H assay. Using criteria for the design of efficient small interfering RNAs (siRNA) and a secondary structure model of the viral 5’UTR, several DNA 19-mers were designed against partly double-stranded RNA regions. Target sites for DNA 19-mers were located opposite the sites which had been confirmed as accessible for hybridization. Three pairs of DNA 19-mers and the helper 2’-O-methyl-16-mers were able to effectively induce RNase H cleavage in vitro. For cellular assays, the DNA 19-mers were replaced by siRNAs, and the corresponding three pairs of siRNA-helper oligomer tools were found to target 5’UTR efficiently in a reporter construct in HeLa cells. Addition of the helper oligomer improved silencing capacity of the respective siRNA. We assume that the described procedure will generally be useful for designing of nucleic acid-based tools to silence highly structured RNA targets.
Collapse
|