title: Zinc chelation: a metallothionein 2A's mechanism of action involved in osteosarcoma cell death and chemotherapy resistance.
abstract: Osteosarcoma is the most common primary tumor of bone occurring in children and adolescents. The histological response to chemotherapy represents a key clinical factor related to survival. We previously showed that statins exhibit antitumor effects in vitro, inducing apoptotic cell death, reducing cell migration and invasion capacities and strengthening cytotoxic effects in combination with standard drugs. Comparative transcriptomic analysis between control and statin-treated cells revealed strong expression of several genes, including metallothionein (MT) 2A. MT2A overexpression by lentiviral transduction reduced bioavailable zinc levels, an effect associated with reduced osteosarcoma cell viability and enhanced cell differentiation. In contrast, MT2A silencing did not modify cell viability but strongly inhibited expression of osteoblastic markers and differentiation process. MT2A overexpression induced chemoresistance to cytotoxic drugs through direct chelation of platinum-containing drugs and indirect action on p53 zinc-dependent activity. In contrast, abrogation of MT2A enhanced cytotoxic action of chemotherapeutic drugs on osteosarcoma cells. Finally, clinical samples derived from chemonaive biopsies revealed that tumor cells expressing low MT2A levels correspond to good prognostic (good responder patients with longer survival rate), whereas high MT2A levels were associated with adverse prognosis (poor responder patients). Taken together, these data show that MT2A contributes to chemotherapy resistance in osteosarcoma, an effect partially mediated by zinc chelation. The data also suggest that MT2A may be a potential new prognostic marker for osteosarcoma sensitivity to chemotherapy.
authors.affiliation: 1] INSERM, U606, Paris F-75010, France [2] Université Paris Diderot, Sorbonne Paris Cité, Paris F-75013, France [3] INSERM, U981, Villejuif F-94805, France [4] Gustave Roussy, Villejuif F-94805, France [5] Université Paris-Sud XI, Kremlin-Bicêtre F-94270, France.
authors.forename: N
authors.initials: N
authors.lastname: Habel
authors.forename: Z
authors.initials: Z
authors.lastname: Hamidouche
authors.forename: I
authors.initials: I
authors.lastname: Girault
authors.forename: A
authors.initials: A
authors.lastname: Patiño-García
authors.forename: F
authors.initials: F
authors.lastname: Lecanda
authors.forename: P J
authors.initials: PJ
authors.lastname: Marie
authors.forename: O
authors.initials: O
authors.lastname: Fromigué
mesh_terms: D000293:Adolescent; D000069059:Atorvastatin; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002614:Chelating Agents / Q000494:pharmacology*; D002648:Child; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D006538:Heptanoic Acids / Q000494:pharmacology; D006801:Humans; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012516:Osteosarcoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D011379:Prognosis; D011487:Protein Conformation; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; D006538:Heptanoic Acids; C491053:MT2A protein, human; D011758:Pyrroles; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D008668:Metallothionein; D000069059:Atorvastatin; D015032:Zinc