LncRNA MAGI2-AS3 inhibits hepatocellular carcinoma cell proliferation and migration by targeting the miR-374b-5p/SMG1 signaling pathway

Long noncoding RNAs (lncRNAs) have been proven to play critical roles in cancer progression. Recently, lncRNA MAGI2-AS3 has been revealed to be a tumor suppressor and inhibit cell growth by targeting the Fas/FasL signalling pathway in breast cancer. However, the role and underlying mechanism of MAGI2-AS3 in hepatocellular carcinoma (HCC) remain largely unknown. In the current study, we found that MAGI2-AS3 expression is downregulated in HCC tissues and closely associated with some clinical characteristics (tumor size, lymph node metastasis, and TNM stage) and poor overall survival. Overexpression of MAGI2-AS3 inhibits HCC cell proliferation and migration in vitro, while impedes tumor growth in vivo accordantly. In addition, our data suggest that MAGI2-AS3 could function as an endogenous sponge of miR-374b-5p by directly binding to it and suppressing its expression. Furthermore, miR-374b-5p upregulation could restore the inhibitory effect of MAGI2-AS3 on HCC cells processes. Moreover, suppressor with morphogenetic effect on genitalia family member 1 (SMG1) is positively regulated by MAGI2-AS3 via absorbing miR-374b-5p in HCC cells. More important, SMG1 knockdown reverses the suppressive function of MAGI2-AS3 in HCC cell processes. Taken together, we reveal a functional MAGI2-AS3/miR-374b-5p/SMG1 axis that suppresses HCC progression, potently suggesting a new road for HCC treatment.     

Long noncoding MAGI2-AS3 promotes colorectal cancer progression through regulating miR-3163/TMEM106B axis

Colorectal cancer (CRC), is mostly derived from normal colon epithelial cells, and has been reported to be one of most common gastrointestinal malignancies globally. An increasing number of researchers have claimed that long noncoding RNAs (lncRNAs) exert significant functions in tumor progression. Nevertheless, the function of MAGI2-AS3 remains uncertain in CRC. The expression of MAGI2-AS3, miR-3163, and transmembrane protein 106B (TMEM106B) messenger RNA was examined by quantitative real-time polymerase chain reaction. Cell apoptosis was measured by caspase-3 activity test. Cell proliferation was tested by cell-counting kit 8 and 5-ethynyl-2′-deoxyuridine assays. Cell migration was detected by transwell assay. Western blot analysis examined the protein expression of TMEM106B. The expression of Ki-67 was evaluated by immunohistochemistry assay. The binding capacity between miR-3163 and MAGI2-AS3 (or TMEM106B) was studied by radioimmunoprecipitation and luciferase reporter assays. The expression of MAGI2-AS3 and TMEM106B was conspicuously upregulated whereas miR-3163 presented lower expression in CRC cells. MAGI2-AS3 deficiency facilitated cell apoptosis but hampered cell proliferation and migration. MAGI2-AS3 combined with miR-3163 and negatively regulated miR-3163 expression. In addition, the administration of sh-MAGI2-AS3 or miR-3163 mimics suppressed CRC cell growth in vivo. Subsequently, miR-3163 targeted TMEM106B and the transfection of sh-MAGI2-AS3 or miR-3163 mimics downregulated TMEM106B expression. Rescue assays verified that TMEM106B overexpression recovered the effects of MAGI2-AS3 inhibition on cell apoptosis, proliferation, and migration in CRC. MAGI2-AS3 drives CRC progression through regulating miR-3163/TMEM106B axis. This supplies innovative insights on the investigation of molecular mechanism in CRC progression.     

MiR-487a Promotes TGF-β1-induced EMT,the Migration and Invasion of Breast Cancer Cells by Directly Targeting MAGI2

Tumor metastasis is a complex and multistep process and its exact molecular mechanisms remain unclear. We attempted to find novel microRNAs (miRNAs) contributing to the migration and invasion of breast cancer cells. In this study, we found that the expression of miR-487a was higher in MDA-MB-231breast cancer cells with high metastasis ability than MCF-7 breast cancer cells with low metastasis ability and the treatment with transforming growth factor β1 (TGF-β1) significantly increased the expression of miR-487a in MCF-7 and MDA-MB-231 breast cancer cells. Subsequently, we found that the transfection of miR-487a inhibitor significantly decreased the expression of vimentin, a mesenchymal marker, while increased the expression of E-cadherin, an epithelial marker, in both MCF-7 cells and MDA-MB-231 cells. Also, the inactivation of miR-487a inhibited the migration and invasion of breast cancer cells. Furthermore, our findings demonstrated that miR-487a directly targeted the MAGI2 involved in the stability of PTEN. The down-regulation of miR-487a increased the expression of p-PTEN and PTEN, and reduced the expression of p-AKT in both cell lines. In addition, the results showed that NF-kappaB (p65) significantly increased the miR-487a promoter activity and expression, and TGF-β1 induced the increased miR-487a promoter activity via p65 in MCF-7 cells and MDA-MB-231 cells. Moreover, we further confirmed the expression of miR-487a was positively correlated with the lymph nodes metastasis and negatively correlated with the expression of MAGI2 in human breast cancer tissues. Overall, our results suggested that miR-487a could promote the TGF-β1-induced EMT, the migration and invasion of breast cancer cells by directly targeting MAGI2.     

MAGI

By incorporating annotation information into the analysis of next-generation sequencing DNA methylation data, we provide an improvement in performance over current testing procedures. Methylation analysis using genome information (MAGI) is applicable for both unreplicated and replicated data, and provides an effective analysis for studies with low sequencing depth. When compared with current tests, the annotation-informed tests provide an increase in statistical power and offer a significance-based interpretation of differential methylation.     

Long noncoding RNA MAGI1-IT1 regulates cardiac hypertrophy by modulating miR-302e/DKK1/Wnt/beta-catenin signaling pathway

Cardiac hypertrophy (CH) is an adaptive cardiac response to overload whose decompensation eventually leads to heart failure or sudden death. Recently, accumulating studies have indicated the implication of long noncoding RNAs (lncRNAs) in CH progression. MAGI1-IT1 is a newly-identified lncRNA that is highly associated with CH, while its specific role in CH progression remains masked. In this study, we uncovered that MAGI1-IT1 was distinctly downregulated in angiotensin (Ang) II-induced hypertrophic H9c2 cells. Also, MAGI1-IT1 overexpression in Ang II-treated H9c2 cells strikingly abolished the enlarged surface area and the enhanced levels of hypertrophic markers such as ANP, BNP, and β-MHC. Mechanically, we found MAGI1-IT1 sponged miR-302e which was identified as a hypertrophy-facilitator here, and that miR-302e upregulation countervailed the inhibition of MAGI1-IT1 overexpression on hypertrophic cells. Moreover, it was confirmed that MAGI1-IT1 boosted DKK1 expression by absorbing miR-302e. Subsequently, we also illustrated that MAGI1-IT1 inactivated Wnt/beta-catenin signaling through a DKK1-dependent pathway. Finally, both the DKK1 inhibition and LiCI (Wnt activator) supplement abrogated the hypertrophy-suppressive impact of MAGI1-IT1 on Ang II-simulated hypertrophic H9c2 cells. Jointly, our findings disclosed that MAGI1-IT1 functioned as a negative regulator in CH through inactivating Wnt/beta-catenin pathway via targeting miR-302e/DKK1 axis, revealing a novel road for CH treatment.     

MAGI: Methylation analysis using genome information

By incorporating annotation information into the analysis of next-generation sequencing DNA methylation data, we provide an improvement in performance over current testing procedures. Methylation analysis using genome information (MAGI) is applicable for both unreplicated and replicated data, and provides an effective analysis for studies with low sequencing depth. When compared with current tests, the annotation-informed tests provide an increase in statistical power and offer a significance-based interpretation of differential methylation.     

Long non‐coding RNA ZEB2‐AS1 promotes the proliferation,metastasis and epithelial mesenchymal transition in triple‐negative breast cancer by epigenetically activating ZEB2

The triple‐negative breast cancer is the most malignant type of breast cancer. Its pathogenesis and prognosis remain poor despite the significant advances in breast cancer diagnosis and therapy. Meanwhile, long noncoding RNAs (LncRNAs) play a pivotal role in the progression of malignant tumors. In this study, we found that LncRNA‐ZEB2‐AS1 was dramatically up‐regulated in our breast cancer specimens and cells (MDA231), especially in metastatic tumor specimens and highly invasive cells, and high lncRNA‐ZEB2‐AS1 expression is associated with clinicopathologic features and short survival of breast cancer patients. LncRNA‐ZEB2‐AS1 promotes the proliferation and metastasis of MDA231 cells in SCID mice. Thus, it is regarded as an oncogene in triple‐negative breast cancer. It is mainly endo‐nuclear and situated near ZEB2, positively regulating ZEB2 expression and activating the epithelial mesenchymal transition via the PI3K/Akt/GSK3β/Zeb2 signaling pathway. Meanwhile, EGF‐induced F‐actin polymerization in MDA231 cells can be suppressed by reducing lncRNA‐ZEB2‐AS1 expression. The migration and invasion of triple‐negative breast cancer can be altered through cytoskeleton rearrangement. In summary, we demonstrated that lncRNA‐ZEB2‐AS1 is an important factor affecting the development of triple‐negative breast cancer and thus a potential oncogene target.     

Endoplasmic reticulum stress‐induced exosomal miR‐27a‐3p promotes immune escape in breast cancer via regulating PD‐L1 expression in macrophages

Immune escape of breast cancer cells contributes to breast cancer pathogenesis. Tumour microenvironment stresses that disrupt protein homeostasis can produce endoplasmic reticulum (ER) stress. The miRNA‐mediated translational repression of mRNAs has been extensively studied in regulating immune escape and ER stress in human cancers. In this study, we identified a novel microRNA (miR)‐27a‐3p and investigated its mechanistic role in promoting immune evasion. The binding affinity between miR‐27a‐3p and MAGI2 was predicted using bioinformatic analysis and verified by dual‐luciferase reporter assay. Ectopic expression and inhibition of miR‐27a‐3p in breast cancer cells were achieved by transduction with mimics and inhibitors. Besides, artificial modulation of MAGI2 and PTEN was done to explore their function in ER stress and immune escape of cancer cells. Of note, exosomes were derived from cancer cells and co‐cultured with macrophages for mechanistic studies. The experimental data suggested that ER stress biomarkers including GRP78, PERK, ATF6, IRE1α and PD‐L1 were overexpressed in breast cancer tissues relative to paracancerous tissues. Endoplasmic reticulum stress promoted exosome secretion and elevated exosomal miR‐27a‐3p expression. Elevation of miR‐27a‐3p and PD‐L1 levels in macrophages was observed in response to exosomes‐overexpressing miR‐27a‐3p in vivo and in vitro. miR‐27a‐3p could target and negatively regulate MAGI2, while MAGI2 down‐regulated PD‐L1 by up‐regulating PTEN to inactivate PI3K/AKT signalling pathway. Less CD4⁺, CD8⁺ T cells and IL‐2, and T cells apoptosis were observed in response to co‐culture of macrophages and CD3⁺ T cells. Conjointly, exosomal miR‐27a‐3p promotes immune evasion by up‐regulating PD‐L1 via MAGI2/PTEN/PI3K axis in breast cancer.     

lncRNA MAGI2-AS3下调miR-31-5p抑制肺腺癌细胞的增殖、迁移、侵袭并促进凋亡

目的研究lncRNA MAGI2-AS3对肺癌A549细胞增殖、迁移、侵袭和凋亡的影响和潜在的分子机制。方法根据转染载体不同将A549细胞分为pcDNA3.1组(转染pcDNA3.1)、pcDNA3.1-MAGI2-AS3组(转染pcDNA3.1-MAGI2-AS3)、anti-miR-NC组(转染anti-miR-NC)、anti-miR-31-5p组(转染anti-miR-31-5p)、pcDNA3.1-MAGI2-AS3+miR-NC组(共转染pcDNA3.1-MAGI2-AS3和miR-NC)、pcDNA3.1-MAGI2-AS3+miR-31-5p组(共转染pcDNA3.1-MAGI2-AS3和miR-31-5p mimics)。实时荧光定量PCR(qRT-PCR)检测miR-31-5p和MAGI2-AS3 RNA的表达,四氮唑蓝(MTT)法测定A549细胞增殖活性,Transwell实验检测细胞迁移和侵袭能力,双荧光素酶报告系统验证MAGI2-AS3与miR-31-5p的调控关系,流式细胞术检测细胞凋亡与周期。两组间比较采用独立样本t检验进行分析;多组间比较采用单因素方差分析,组内多重比较采用SNK-q检验。结果与人正常肺细胞HBE相比,肺癌细胞A549中的MAGI2-AS3表达量(0.48±0.03比1.29±0.06)降低,miR-31-5p表达量(1.01±0.05比0.25±0.02)升高;与pcDNA3.1组比较,pcDNA3.1-MAGI2-AS3组A549细胞活力(0.48±0.04比0.77±0.06)、迁移[(81.33±2.87)个比(124.33±3.09)个]和侵袭[(32.00±2.83)个比(53.00±3.27)个]细胞数、S期细胞所占比例(23.01﹪±1.00﹪比32.95﹪±1.06﹪)均降低,凋亡率(19.95﹪±1.25﹪比7.23﹪±0.51﹪)、G0-G1期细胞所占比例(43.58﹪±2.15﹪比33.56﹪±1.23﹪)均升高;与anti-miR-NC组比较,anti-miR-31-5p组A549细胞活力(0.53±0.04比0.78±0.06)、迁移[(76.00±3.74)个比(108.33±2.87)个]和侵袭[(30.00±1.63)个比(42.33±2.05)个]细胞数、S期细胞所占比例(24.43﹪±1.13﹪比32.91﹪±1.08﹪)降低,凋亡率(18.21﹪±1.24﹪比7.29﹪±0.51﹪)、G0-G1期细胞所占比例(41.56﹪±2.19﹪比33.53﹪±1.27﹪)升高,差异有统计学意义(P均<0.05);双荧光素酶报告系统结果显示,MAGI2-AS3靶向负调控miR-31-5p的表达。与pcDNA3.1-MAGI2-AS3+miR-NC组比较,pcDNA3.1-MAGI2-AS3+miR-31-5p组A549细胞活力(0.68±0.06比0.50±0.04)、迁移[(91.00±1.63)个比(52.67±2.62)个]和侵袭[(62.67±2.49)个比(31.67±4.03个)]细胞数升高,凋亡率(10.59﹪±1.0﹪比21.11﹪±1.14﹪)降低,差异有统计学意义(P均<0.05)。结论lncRNA MAGI2-AS3通过靶向miR-31-5p抑制A549细胞的增殖、迁移和侵袭,促进细胞凋亡。lncRNA MAGI2-AS3是肺癌潜在分子治疗靶点。     

Surface plasmon resonance analysis of the binding of high‐risk mucosal HPV E6 oncoproteins to the PDZ1 domain of the tight junction protein MAGI‐1

The E6 oncoproteins from high‐risk mucosal human papillomavirus (HPV) induce cervical cancer via two major activities, the binding and the degradation of the p53 protein and PDZ domain‐containing proteins. Human MAGI‐1 is a multi‐PDZ domain protein implicated into protein complex assembly at cell–cell contacts. High‐risk mucosal HPV E6 proteins interact with the PDZ1 domain of MAGI‐1 via a C‐terminal consensus binding motif. Here, we developed a medium throughput protocol to accurately measure by surface plasmon resonance affinity constants of protein domains binding to peptidic sequences produced as recombinant fusions to the glutathione‐S‐transferase (GST). This approach was applied to measure the binding of MAGI‐1 PDZ1 to the C‐termini of viral or cellular proteins. Both high‐risk mucosal HPV E6 C‐terminal peptides and cellular partners of MAGI‐1 PDZ1 bind to MAGI‐1 PDZ1 with comparable dissociation constants in the micromolar range. MAGI‐1 PDZ1 shows a preference for C‐termini with a valine at position 0 and a negative charge at position ?3, confirming previous studies performed with HPV18 E6. A detailed combined analysis via site‐directed mutagenesis of the HPV16 C‐terminal peptide and PDZ1 indicated that interactions mediated by charged residues upstream the PDZ‐binding motif strongly contribute to binding selectivity of this interaction. In addition, our work highlighted the K₄₉₉ residue of MAGI‐1 as a novel determinant of binding specificity. Finally, we showed that MAGI‐1 PDZ1 also binds to the C‐termini of LPP and Tax proteins, which were already known to bind to PDZ proteins but not to MAGI‐1. Copyright © 2010 John Wiley & Sons, Ltd.     

LncRNA GAS6‐AS2 promotes bladder cancer proliferation and metastasis via GAS6‐AS2/miR‐298/CDK9 axis

Long noncoding RNAs (lncRNAs) have been proved to play important roles in carcinogenesis and development of numerous cancers, but their biological functions in bladder cancer remain largely unknown. In this study, a novel lncRNA termed GAS6‐AS2 were primary identified, and its roles as well as mechanisms in regulating proliferation and metastasis of bladder cancer cells were investigated. Clinically, GAS6‐AS2 was significantly up‐regulated in bladder cancer tissues and positively correlated with tumour stages and poor prognosis. Moreover, expression of GAS6‐AS2 was also increased in bladder cancer cells compared with normal bladder cells. Further investigating the roles of GAS6‐AS2, we found GAS6‐AS2 regulated proliferation and proliferative activity of bladder cancer cells via inducing G1 phase arrest. What's more, we found that GAS6‐AS2 contributed to metastatic abilities of cells. In mechanism, GAS6‐AS2 could function as a competitive endogenous RNA (ceRNA) via direct sponging miR‐298, which further regulating the expression of CDK9. Finally, we also proved that GAS6‐AS2 knockdown suppressed tumour growth and metastasis in vivo. In conclusion, our study proved that GAS6‐AS2 could function as a ceRNA and promote the proliferation and metastasis of bladder cancer cells, which provided a novel prognostic marker for bladder cancer patients in clinic.     

lncRNA NR2F1‐AS1 promotes breast cancer angiogenesis through activating IGF‐1/IGF‐1R/ERK pathway

Long non‐coding RNAs (lncRNAs) take various effects in cancer mostly through sponging with microRNAs (miRNAs). lncRNA NR2F1‐AS1 is found to promote tumour progression in hepatocellular carcinoma, endometrial cancer and thyroid cancer. However, the role of lncRNA NR2F1‐AS1 in breast cancer angiogenesis remains unknown. In this study, we found lncRNA NR2F1‐AS1 was positively related with CD31 and CD34 in breast cancer through Pearson's correlation analysis, while lncRNA NR2F1‐AS1 transfection promoted human umbilical vascular endothelial cell (HUVEC) tube formation. In breast cancer cells, lncRNA NR2F1‐AS1 enhanced the HUVEC proliferation, tube formation and migration ability through tumour‐conditioned medium (TCM). In zebrafish model, lncRNA NR2F1‐AS1 increased the breast cancer cell‐related neo‐vasculature and subsequently promoted the breast cancer cell metastasis. In mouse model, lncRNA NR2F1‐AS1 promoted the tumour vessel formation, increased the micro vessel density (MVD) and then induced the growth of primary tumour. Mechanically, lncRNA NR2F1‐AS1 increased insulin‐like growth factor‐1 (IGF‐1) expression through sponging miRNA‐338‐3p in breast cancer cells and then activated the receptor of IGF‐1 (IGF‐1R) and extracellular signal‐regulated kinase (ERK) pathway in HUVECs. These results indicated that lncRNA NR2F1‐AS1 could promote breast cancer angiogenesis through IGF‐1/IGF‐1R/ERK pathway.     

Decreased expression of EZH2 reactivates RASSF2A by reversal of promoter methylation in breast cancer cells

EZH2, the catalytic subunit of polycomb repressor complex 2, has oncogenic properties, whereas RASSF2A, a Ras association domain family protein, has a tumor suppressor role in many types of human cancer. However, the interrelationship between these two genes remains unclear. Here, we showed that the downregulation of EZH2 reduces CpG island methylation of the RASSF2A promoter, thereby leading to increased RASSF2A expression. Our findings also showed that knockdown of EZH2 increased RASSF2A expression in the human breast cancer cell line MCF‐7 in cooperation with DNMT1. This was similar to the effect of 5‐Aza‐CdR, a DNA methylation inhibitor that reactivates tumor suppressor genes and activated RASSF2A expression in our study. The EZH2 inhibitor DZNep markedly suppressed the proliferation, migration, and invasion of MCF‐7 cells treated with ADR and TAM. EZH2 inhibits the expression of tumor suppressor gene RASSF2A via promoter hypermethylation. Thus, it plays an important role in tumorigenesis and is a potential therapeutic target for the treatment of breast cancer.     

MAGI proteins can differentially regulate the signaling pathways of 5-HT2AR by enhancing receptor trafficking and PLC recruitment

MAGI proteins are Membrane-Associated Guanylate Kinase Inverted proteins that belong to the MAGUK family. They are scaffolding proteins that were shown to mediate the trafficking and signaling of various G protein-coupled receptors (GPCRs). They contain PDZ domains in their structure and many GPCRs interact with these proteins via the PDZ motifs on the carboxyl terminal end of a receptor. In a PDZ overlay assay performed with the carboxyl terminal tail of 5-HT_2AR, we were able to detect all three members of the MAGI subfamily, MAGI-1, MAGI-2 and MAGI-3 as interacting PDZ proteins. The PDZ motif of 5-HT_2AR consists of three amino acids; serine (S), cysteine (C) and valine (V). In this study, we characterize these 5-HT_2AR interactions with MAGI proteins. We first confirm the interaction using co-immunopricipitation and illustrate that the interaction is PDZ motif-dependent in human embryonic kidney (HEK 293) cells. We then assess the effects of overexpression and knockdown of the MAGI proteins on the internalization, trafficking and signaling of 5-HT_2AR. We find that knockdown of either MAGI-1 or MAGI-3 using siRNA results in a significant reduction in the internalization of 5-HT_2AR. As for signaling, we report here that MAGI proteins can modulate the signaling via the two transduction pathways that 5-HT_2AR can activate. We illustrate a significant effect of modulating MAGI proteins expression on 5-HT-stimulated IP formation. We demonstrate an enhancement in 5-HT_2AR-stimulated IP formation upon MAGI proteins overexpression. In addition, we show that knockdown of MAGI proteins with siRNA leads to a significant reduction in 5-HT_2AR-stimulated IP formation. Furthermore, we illustrate a significant increase in 5-HT-stimulated ERK1/2 phosphorylation upon MAGI proteins knockdown. Interestingly, this effect on ERK1/2 activation is PDZ motif-independent. We also suggest two possible mechanisms of regulation for the effect of MAGI proteins on 5-HT_2AR function. One mechanism involves the regulation of cell surface expression since we show that both MAGI-2 and MAGI-3 can enhance receptor trafficking to the plasma membrane when overexpressed in HEK 293 cells. The other mechanism points to regulation of second messengers in the signaling pathways. Specifically, we show that overexpression of any of the three MAGI proteins can enhance the recruitment of PLCβ3 to 5-HT_2AR. In addition, we report a negative effect for knocking down MAGI-3 on β-arrestin recruitment to the receptor and this effect is PDZ motif-independent. Taken together, our findings document distinct roles for the three MAGI proteins in regulating 5-HT_2AR trafficking and signaling and emphasize the importance of studying PDZ proteins and their interactions with GPCRs to regulate their function.     

LncRNA NR2F2‐AS1 promotes tumourigenesis through modulating BMI1 expression by targeting miR‐320b in non‐small cell lung cancer

Recently, long noncoding RNAs (lncRNAs) are attracting wide attention in the field of cancer research because of its important role in cancer diagnosis and prognosis. But studies on the biological effects and relevant mechanisms of lncRNAs in non‐small cell lung cancer (NSCLC) remain few and need to be enriched. Our study discussed the expression and biological effects of LncRNA NR2F2‐AS1, and further explored its possible molecular mechanisms. As a result, elevated expression of NR2F2‐AS1 was detected in NSCLC tissues and cells and was remarkably associated with the tumor, node, metastasis (TNM) stage and the status of lymphatic metastasis of patients. Down‐regulated NR2F2‐AS1 contributed to the promotion of cell apoptosis and the inhibition of cell proliferation and invasion in A549 and SPC‐A‐1 cells in vivo and vitro. Through bioinformatics analysis, NR2F2‐AS1 functions as a ceRNA directly binding to miR‐320b, BMI1 was a direct target of miR‐320b. Combined with the following cellular experiments, the data showed that NR2F2‐AS1 may influence the NSCLC cell proliferation, invasion and apoptosis through regulating miR‐320b targeting BMI1.     

Inhibition of breast cancer cell growth by the combination of clofarabine and sulforaphane involves epigenetically mediated CDKN2A upregulation

Many antineoplastic nucleoside analogue-based combinatorial strategies focused on remodelling aberrant DNA methylation patterns have been developed. The number of studies demonstrate high efficacy of bioactive phytochemicals in support of conventional chemotherapy. Our recent discoveries of the epigenetic effects of clofarabine (2′-deoxyadenosine analogue, antileukaemic drug) and clofarabine-based combinations with dietary bioactive compounds in breast cancer cells led us to look for more DNA methylation targets of these cancer-preventive agents. In the present study, using methylation-sensitive restriction analysis (MSRA) and qPCR, we showed that clofarabine in combination with sulforaphane, a phytochemical from cruciferous vegetables, significantly reactivates DNA methylation-silenced CDKN2A tumour suppressor and inhibits cancer cell growth at a non-invasive breast cancer stage.