title: Diet-derived 25-hydroxyvitamin D3 activates vitamin D receptor target gene expression and suppresses EGFR mutant non-small cell lung cancer growth in vitro and in vivo.
abstract: Epidemiologic studies implicate vitamin D status as a factor that influences growth of EGFR mutant lung cancers. However, laboratory based evidence of the biological effect of vitamin D in this disease is lacking. To fill this knowledge gap, we determined vitamin D receptor (VDR) expression in human lung tumors using a tissue microarray constructed of lung cancer cases from never-smokers (where EGFR gene mutations are prevalent). Nuclear VDR was detected in 19/19 EGFR mutant tumors. Expression tended to be higher in tumors with EGFR exon 19 deletions than those with EGFR L858R mutations. To study anti-proliferative activity and signaling, EGFR mutant lung cancer cells were treated with the circulating metabolite of vitamin D, 25-hydroxyvitamin D3 (25D3). 25D3 inhibited clonogenic growth in a dose-dependent manner. CYP27B1 encodes the 1α-hydroxylase (1αOHase) that converts 25D3 to the active metabolite, 1,25-dihydroxyvitamin D3 (1,25D3). Studies employing VDR siRNA, CYP27B1 zinc finger nucleases, and pharmacologic inhibitors of the vitamin D pathway indicate that 25D3 regulates gene expression in a VDR-dependent manner but does not strictly require 1αOHase-mediated conversion of 25D3 to 1,25D3. To determine the effects of modulating serum 25D3 levels on growth of EGFR mutant lung tumor xenografts, mice were fed diets containing 100 or 10,000 IU vitamin D3/kg. High dietary vitamin D3 intake resulted in elevated serum 25D3 and significant inhibition of tumor growth. No toxic effects of supplementation were observed. These results identify EGFR mutant lung cancer as a vitamin D-responsive disease and diet-derived 25D3 as a direct VDR agonist and therapeutic agent.
authors.affiliation: Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Alissa R
authors.initials: AR
authors.lastname: Verone-Boyle
authors.affiliation: Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Shoemaker
authors.affiliation: Department of Bioinformatics & Biostatistics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Kristopher
authors.initials: K
authors.lastname: Attwood
authors.affiliation: Department of Pathology and Center for Personalized Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Carl D
authors.initials: CD
authors.lastname: Morrison
authors.affiliation: Heartland Assays LLC, Ames, IA 50010, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Makowski
authors.affiliation: Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Battaglia
authors.affiliation: Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Hershberger
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002112:Calcifediol / Q000008:administration & dosage / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D004032:Diet; D066246:ErbB Receptors / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008819:Mice, Nude; D009154:Mutation; D034622:RNA Interference; D018167:Receptors, Calcitriol / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous; D047368:Tumor Burden / Q000187:drug effects / Q000235:genetics
chemical_list: D018167:Receptors, Calcitriol; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D066246:ErbB Receptors; D002112:Calcifediol
keywords: CYP27B1; EGFR; non-small cell lung cancer (NSCLC); vitamin D; zinc finger nucleases