Antigene and Antiproliferative Effects of Triplex-Forming Oligonucleotide (TFO) Targeted on hmgb1 Gene in Human Hepatoma Cells

Author(s):

Neelam Lohani and Moganty R. Rajeswari*   Pages 1943 - 1955 ( 13 )

Abstract:

<P>Background: The high mobility group box 1 (hmgb1) is one of the frequently over-expressed genes whose aberrant expression is reported in a number of human cancers. Various strategies are underway to inhibit hmgb1 expression in cancer cells having considerable therapeutic value. </P><P> Objective: The present work involves selective transcriptional inhibition of the hmgb1 gene using selective DNA triplex structure-based gene technology. Here, the promoter region of the hmgb1 gene at position (-183 to -165) from the transcription start site as a target was selected using bioinformatic tools. </P><P> Methods: The DNA triplex formation by the DNA of the target gene and TFO was confirmed using UV absorption spectroscopy, Circular Dichroism, and Isothermal Calorimetry. </P><P> Results: Treatment of HepG2 cell with specific Triplex-forming Oligonucleotide significantly downregulated HMGB1 expression level at mRNA and protein levels by 50%, while the classical anticancer drugs, actinomycin/ adriamycin as positive controls showed 65% and the combination of TFO and drug decreased by 70%. The anti-proliferative effects of TFO correlated well with the fact of accumulation of cells in the Go phase and apoptotic cell death. Further, the binding of anti-cancer drugs to hmgb1 is stronger in DNA triplex state as compared to hmgb1 alone, suggesting the combination therapy as a better option. </P><P> Conclusion: Therefore, the ability of hmgb1 targeted triplex-forming oligonucleotide in combination with triplex selective anticancer drug holds promise in the treatment of malignancies associated with hmgb1 overexpression. The result obtained may open up new vistas to provide a basis for the rational drug design and searching for high-affinity ligands with a high triplex selectivity.</P>

Keywords:

HMGB1, DNA triplex, triplex-forming oligonucleotide, hepatocellular carcinoma, antigene, transcription.

Affiliation:

Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, Department of Biochemistry, All India Institute of Medical Sciences, New Delhi

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