title: TRAIL-based tumor sensitizing galactoxyloglucan, a novel entity for targeting apoptotic machinery.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for cancer therapy due to its ability to selectively induce apoptosis in cancer cells, without causing significant toxicity in normal tissues. We previously reported that galactoxyloglucan (PST001) possesses significant antitumor and immunomodulatory properties. However, the exact mechanism in mediating this anticancer effect is unknown. This study, for the first time, indicated that PST001 sensitizes non-small cell lung cancer (A549) and nasopharyngeal (KB) cells to TRAIL-mediated apoptosis. In vitro studies suggested that PST001 induced apoptosis primarily via death receptors and predominantly activated caspases belonging to the extrinsic apoptotic cascade. Microarray profiling of PST001 treated A549 and KB cells showed the suppression of survivin (BIRC5) and anti-apoptotic Bcl-2, as well as increased cytochrome C. TaqMan low density array analysis of A549 cells also confirmed that the induction of apoptosis by the polysaccharide occurred through the TRAIL-DR4/DR5 pathways. This was finally confirmed by in silico analysis, which revealed that PST001 binds to TRAIL-DR4/DR5 complexes more strongly than TNF and Fas ligand-receptor complexes. In summary, our results suggest the potential of PST001 to be developed as an anticancer agent that not only preserves innate biological activity of TRAIL, but also sensitizes cancer cells to TRAIL-mediated apoptosis.
authors.affiliation: Laboratory of Biopharmaceuticals and Nanomedicine, Division of Cancer Research, Regional Cancer Centre, Trivandrum, Kerala 695011, India.
authors.forename: S R
authors.initials: SR
authors.lastname: Aravind
authors.affiliation: Laboratory of Biopharmaceuticals and Nanomedicine, Division of Cancer Research, Regional Cancer Centre, Trivandrum, Kerala 695011, India.
authors.forename: Manu M
authors.initials: MM
authors.lastname: Joseph
authors.affiliation: Department of Hematopathology, UT MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA.
authors.forename: Suraj K
authors.initials: SK
authors.lastname: George
authors.affiliation: Department of Biotechnology and Microbiology and Inter-University Centre for Bioscience, Kannur University, Thalassery Campus, Palayad, Kerala 670661, India.
authors.forename: K V
authors.initials: KV
authors.lastname: Dileep
authors.affiliation: Laboratory of Biopharmaceuticals and Nanomedicine, Division of Cancer Research, Regional Cancer Centre, Trivandrum, Kerala 695011, India.
authors.forename: Sheeja
authors.initials: S
authors.lastname: Varghese
authors.affiliation: Laboratory of Biopharmaceuticals and Nanomedicine, Division of Cancer Research, Regional Cancer Centre, Trivandrum, Kerala 695011, India.
authors.forename: Alphy
authors.initials: A
authors.lastname: Rose-James
authors.affiliation: Quest International University, Perak, No. 227, Plaza Teh Teng Seng-level 2, Jalan Raja Permaisuri Bainum, 30250 Ipoh, Perak, Malaysia.
authors.forename: Prabha
authors.initials: P
authors.lastname: Balaram
authors.affiliation: Department of Biotechnology and Microbiology and Inter-University Centre for Bioscience, Kannur University, Thalassery Campus, Palayad, Kerala 670661, India.
authors.forename: C
authors.initials: C
authors.lastname: Sadasivan
authors.affiliation: Laboratory of Biopharmaceuticals and Nanomedicine, Division of Cancer Research, Regional Cancer Centre, Trivandrum, Kerala 695011, India. Electronic address: lekhasree64@yahoo.co.in.
authors.forename: T T
authors.initials: TT
authors.lastname: Sreelekha
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002843:Chromatin / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005936:Glucans / Q000494:pharmacology*; D006801:Humans; D062105:Molecular Docking Simulation; D020411:Oligonucleotide Array Sequence Analysis; D011419:Propidium / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*
chemical_list: D017304:Annexin A5; D051017:Apoptosis Regulatory Proteins; D002843:Chromatin; D005456:Fluorescent Dyes; D005936:Glucans; C000601288:PST001; D053221:TNF-Related Apoptosis-Inducing Ligand; D011419:Propidium; D020169:Caspases
keywords: Apoptosis; Microarray; Polysaccharide; TRAIL; Tamarindus indica