Curcumin-Mediated Reversal of p15 Gene Promoter Methylation: Implication in Anti-Neoplastic Action against Acute Lymphoid Leukaemia Cell Line.
Curcumin has been documented to exert anticancer effects by interacting with altered proliferative and apoptotic pathways in cancer models. In this study, we evaluated the potential of curcumin to reverse promoter methylation of the p15 gene in Raji cells and its ability to induce apoptosis and genomic instability. Anti-neoplastic action of curcumin showed an augmentation in reactive oxygen species (ROS) and cell cycle arrest in G1 phase. Subsequently, curcumin- exposed Raji cells showed structural abnormalities in chromosomes. These observations suggest that curcumin also causes ROS-mediated apoptosis and genomic instability. The treatment of Raji cell line with 10 μM curcumin caused hypomethylation of the p15 promoter after six days. Hypomethylation of p15 was further found to be favoured by downregulation of DNA methyltransferase 1 after 10 μM curcumin treatment for six days. Methylation-specific PCR suggested demethylation of the p15 promoter. Demethylation was further validated by DNA sequencing. Reverse-transcription PCR demonstrated that treatment with curcumin (10 μM) for six days led to the up-regulation of p15 and down-regulation of DNA methyltransferase 1. Furthermore, curcumin- mediated reversal of p15 promoter methylation might be potentiated by down-regulation of DNA methyltransferase 1 expression, which was supported by cell cycle analysis. Furthermore, curcumin acts as a double-pronged agent, as it caused apoptosis and promoter hypomethylation in Raji cells.
Department of Biotechnology, Panjab University, Chandigarh, India.
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V
Sharma
Department of Biotechnology, Panjab University, Chandigarh, India.
A K
AK
Jha
Department of Biotechnology, Panjab University, Chandigarh, India.
A
A
Kumar
Department of Biochemistry, Panjab University, Chandigarh, India.
A
A
Bhatnagar
Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi, India.
G
G
Narayan
Department of Biochemistry, Panjab University, Chandigarh, India.
J
J
Kaur
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D019457:Chromosome Breakage / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology* / Q000633:toxicity; D050762:Cyclin-Dependent Kinase Inhibitor p15 / Q000096:biosynthesis* / Q000235:genetics; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis* / Q000235:genetics; D019175:DNA Methylation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004790:Enzyme Induction / Q000187:drug effects; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects*; D042822:Genomic Instability / Q000187:drug effects*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000473:pathology*; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism
D000972:Antineoplastic Agents, Phytogenic; C493966:CDKN2B protein, human; D050762:Cyclin-Dependent Kinase Inhibitor p15; D009363:Neoplasm Proteins; D017382:Reactive Oxygen Species; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D003474:Curcumin