Verticillin A overcomes apoptosis resistance in human colon carcinoma through DNA methylation-dependent upregulation of BNIP3.

Abstract

Drug resistance is a major cause of failure in cancer chemotherapy. Therefore, identification and combined use of adjuvant compounds that can overcome drug resistance may improve the efficacy of cancer therapy. We screened extracts of Verticillium species-infected mushrooms for antitumor compounds and identified the compound Verticillin A as an inducer of hepatoma cell apoptosis in vitro and an inhibitor of tumor xenograft growth in vivo. Verticillin A exhibited a potent apoptosis-sensitizing activity in human colon carcinoma cells exposed to TRAIL or Fas in vitro. Furthermore, Verticillin A effectively sensitized metastatic human colon carcinoma xenograft to TRAIL-mediated growth inhibition in vivo. At the molecular level, we observed that Verticillin A induces cell-cycle arrest in the G₂ phase of the cell cycle in human colon carcinoma cells, markedly upregulating BNIP3 in both hepatoma and colon carcinoma cells. Notably, silencing BNIP3 decreased the sensitivity of tumor cells to Verticillin A-induced apoptosis in the absence or presence of TRAIL. We found that the BNIP3 promoter is methylated in both human hepatoma and colon carcinoma cells and tumor specimens. Verticillin A upregulated the expression of a panel of genes known to be regulated at the level of DNA methylation, in support of the concept that Verticillin A may act by demethylating the BNIP3 promoter to upregulate BNIP3 expression. Taken together, our findings identify Verticillin A as a potent apoptosis sensitizer with great promise for further development as an adjuvant agent to overcome drug resistance in human cancer therapy.

• Authors: Feiyan Liu, Qianqian Liu, Dafeng Yang, Wendy B Bollag, Keith Robertson, Ping Wu, Kebin Liu
• Journal: Cancer research (Cancer Res) Vol. 71 Issue 21 Pg. 6807-16 (Nov 01 2011) ISSN: 1538-7445 [Electronic] United States
• PMID: 21911457 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: ©2011 AACR.

Chemical References

• Antineoplastic Agents, Alkylating
• BNIP3 protein, human
• Fas Ligand Protein
• Indoles
• Membrane Proteins
• Neoplasm Proteins
• Proto-Oncogene Proteins
• RNA, Small Interfering
• Recombinant Proteins
• TNF-Related Apoptosis-Inducing Ligand
• verticillins
• Etoposide
• Cisplatin

Topics

• Adenocarcinoma (genetics, metabolism, pathology, secondary)
• Animals
• Antineoplastic Agents, Alkylating (pharmacology)
• Apoptosis (drug effects)
• Carcinoma, Hepatocellular (genetics, pathology)
• Cell Line, Tumor (drug effects, metabolism)
• Cisplatin (pharmacology)
• Colonic Neoplasms (genetics, metabolism, pathology)
• DNA Methylation (drug effects)
• Drug Resistance, Neoplasm (drug effects)
• Etoposide (pharmacology)
• Fas Ligand Protein (pharmacology)
• Female
• Gene Expression Regulation, Neoplastic (drug effects)
• Humans
• Indoles (pharmacology)
• Liver Neoplasms (genetics, pathology)
• Membrane Proteins (biosynthesis, genetics, physiology)
• Mice
• Mice, Nude
• Neoplasm Proteins (biosynthesis, genetics, physiology)
• Promoter Regions, Genetic
• Proto-Oncogene Proteins (biosynthesis, genetics, physiology)
• RNA Interference
• RNA, Small Interfering (pharmacology)
• Recombinant Proteins (pharmacology)
• TNF-Related Apoptosis-Inducing Ligand (pharmacology)
• Up-Regulation (drug effects)
• Xenograft Model Antitumor Assays