Investigation into the anti-cancer properties of Ganoderma lucidum

Abstract

Ganoderma lucidum is a type of mushroom commonly used in Asia for the promotion of health and longevity. The observed biological activities of G. lucidum include anti-cancer and antiinflammatory effects which may be useful in the treatment and prevention of cancer. As well as current dietary supplements, liquor-based extracts are attracting interest as a vehicle for Ganoderma consumption. We wish to identify whether G. lucidum extracts have any anti-cancer activities in common human cancers: prostate, breast, lung, and colon using tissue culture studies. We also wish to identify the biologically active pathways and genes associated with the anti-cancer activities of G. lucidum using various gene expression analysis techniques. The first part of this study is the extraction of G. lucidum bioactive ingredients. Extraction of the bioactive components is essential as the mushroom is tough and indigestible. Six different Ganoderma extracts were acquired, based on three different traditional means of G. lucidum consumption. The second part of the study involved testing these extracts in well-established models of human cancer cell lines. This was performed in order to identify whether there was an observable growth inhibition associated with the Ganoderma extracts. These studies were followed by the use of Affymetrix GeneChip® PrimeView™ Human Gene Expression Arrays to identify the changes in gene expression due to the treatment of Ganoderma extracts in prostate cancer cell lines (PC3 and DU145). Several key genes identified with Affymetrix analysis were validated using RTPCR, a different technique of quantitative gene expression analysis. We found that all the Ganoderma extracts showed growth inhibition in the cancer cell lines tested. Using Affymetrix microarray analysis, we identified four main biologically active pathways: cell cycle control/apoptosis, cell-cell adhesion, DNA repair, and inflammatory/immune response. Using RT-PCR we tested eleven genes associated with these pathways. The results supported our findings in the Affymetrix analysis. Furthermore, using RT-PCR, we identified that the anti-cancer activity of Ganoderma liquor-based extracts was associated with inflammatory/immune response. Identification of the anti-cancer activities of G. lucidum and their associated pathways warrants further studies of the molecular pathways of G. lucidum anti-cancer activities in advanced cancer models.