Molecular attributes and apoptosis-inducing activities of a putative serine protease isolated from Tiger Milk mushroom (Lignosus rhinocerus) sclerotium against breast cancer cells in vitro
Document Type
Article
Publication Date
1-1-2018
Abstract
Background: The highly valued medicinal tiger milk mushroom (also known as Lignosus rhinocerus) has the ability to cure numerous ailments. Its anticancer activities are well explored, and recently a partially purified cytotoxic protein fraction termed F5 from the mushroom's sclerotial cold water extract consisting mainly of fungal serine proteases was found to exhibit potent selective cytotoxicity against a human breast adenocarcinoma cell line (MCF7) with IC50 value of 3.00 μg/ml. However, characterization of its cell death-inducing activity has yet to be established. Methods: The mechanism involved in the cytotoxic activities of F5 against MCF7 cells was elucidated by flow cytometry-based apoptosis detection, caspases activity measurement, and expression profiling of apoptosis markers by western blotting. Molecular attributes of F5 were further mined from L. rhinocerus's published genome and transcriptome for future exploration. Results and Discussion: Apoptosis induction in MCF7 cells by F5 may involve a cross-talk between the extrinsic and intrinsic apoptotic pathways with upregulation of caspase-8 and -9 activities and a marked decrease of Bcl-2. On the other hand, the levels of pro-apoptotic Bax, BID, and cleaved BID were increased accompanied by observable actin cleavage. At gene level, F5 composed of three predicted nonsynonymous single nucleotide polymorphisms (T > C) and an alternative 5' splice site. Conclusions: Findings from this study provide an advanced framework for further investigations on cancer therapeutics development from L. rhinocerus.
Keywords
Anticancer, Apoptosis, F5, GME4347_g, Lignosus rhinocerus, Serine protease, Tiger milk mushroom
Divisions
fac_med
Funders
Ministry of Education Malaysia: Fundamental Research Grant Scheme (FRGS) FP029-2014A,MAHSA University: MAHSA Research Grant (RP122-09/17),University of Malaya, Kuala Lumpur, Malaysia: UMRG Programme Grant (RP034 A, B, C–17AFR)
Publication Title
PeerJ
Volume
6
Publisher
PeerJ