title: Role of hemoglobin and transferrin in multi-wall carbon nanotube-induced mesothelial injury and carcinogenesis.
abstract: Multi-wall carbon nanotubes (MWCNT) are a form of flexible fibrous nanomaterial with high electrical and thermal conductivity. However, 50-nm MWCNT in diameter causes malignant mesothelioma (MM) in rodents and, thus, the International Agency of Research on Cancer has designated them as a possible human carcinogen. Little is known about the molecular mechanism through which MWCNT causes MM. To elucidate the carcinogenic mechanisms of MWCNT in mesothelial cells, we used a variety of lysates to comprehensively identify proteins specifically adsorbed on pristine MWCNT of different diameters (50 nm, NT50; 100 nm, NT100; 150 nm, NT150; and 15 nm/tangled, NTtngl) using mass spectrometry. We identified >400 proteins, which included hemoglobin, histone, transferrin and various proteins associated with oxidative stress, among which we selected hemoglobin and transferrin for coating MWCNT to further evaluate cytotoxicity, wound healing, intracellular catalytic ferrous iron and oxidative stress in rat peritoneal mesothelial cells (RPMC). Cytotoxicity to RPMC was observed with pristine NT50 but not with NTtngl. Coating NT50 with hemoglobin or transferrin significantly aggravated cytotoxicity to RPMC, with an increase in cellular catalytic ferrous iron and DNA damage also observed. Knockdown of transferrin receptor with ferristatin II decreased not only NT50 uptake but also cellular catalytic ferrous iron. Our results suggest that adsorption of hemoglobin and transferrin on the surface of NT50 play a role in causing mesothelial iron overload, contributing to oxidative damage and possibly subsequent carcinogenesis in mesothelial cells. Uptake of NT50 at least partially depends on transferrin receptor 1. Modifications of NT50 surface may decrease this human risk.
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Okazaki
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hiro
authors.initials: H
authors.lastname: Kohda
authors.affiliation: Division for Medical Research Engineering, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Division for Medical Research Engineering, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Taki
authors.affiliation: Department of Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishioka
authors.affiliation: Laboratory of Pharmaceutical and Medicinal Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Hirayama
authors.affiliation: Laboratory of Pharmaceutical and Medicinal Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
authors.forename: Hideko
authors.initials: H
authors.lastname: Nagasawa
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Toyokuni
mesh_terms: D000327:Adsorption; D000818:Animals; D002273:Carcinogens / Q000737:chemistry / Q000633:toxicity*; D002460:Cell Line; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D006454:Hemoglobins / Q000737:chemistry / Q000502:physiology*; D008297:Male; D008654:Mesothelioma / Q000139:chemically induced / Q000378:metabolism*; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D011916:Rats, Inbred F344; D011990:Receptors, Transferrin / Q000378:metabolism; D014168:Transferrin / Q000737:chemistry / Q000502:physiology*
chemical_list: D002273:Carcinogens; D006454:Hemoglobins; D037742:Nanotubes, Carbon; D011990:Receptors, Transferrin; C545564:Tfrc protein, rat; D014168:Transferrin
keywords: Adsorption; DNA damage; iron; mesothelial cell; multi-wall carbon nanotube