TY - JOUR
T1 - Role of endolysosome function in iron metabolism and brain carcinogenesis
AU - Halcrow, Peter W.
AU - Lynch, Miranda L.
AU - Geiger, Jonathan D.
AU - Ohm, Joyce E.
N1 - Funding Information:
Grant support from the NIH ( ES022030 ) awarded to J.E.O. is acknowledged. JDG acknowledges research support from the National Institute of General Medical Sciences under award numbers P30GM100329 and U54GM115458, the National Institute of Mental Health under award numbers R01MH100972, R01MH105329 and R01MH119000, the National Institute of Neurological Diseases and Stroke (NINDS) under award number 2R01NS065957, and the National Institute of Drug Abuse under award number 2R01DA032444.
Publisher Copyright:
© 2021
PY - 2021/11
Y1 - 2021/11
N2 - Iron, the most abundant metal in human brain, is an essential microelement that regulates numerous cellular mechanisms. Some key physiological roles of iron include oxidative phosphorylation and ATP production, embryonic neuronal development, formation of iron-sulfur clusters, and the regulation of enzymes involved in DNA synthesis and repair. Because of its physiological and pathological importance, iron homeostasis must be tightly regulated by balancing its uptake, transport, and storage. Endosomes and lysosomes (endolysosomes) are acidic organelles known to contain readily releasable stores of various cations including iron and other metals. Increased levels of ferrous (Fe2+) iron can generate reactive oxygen species (ROS) via Fenton chemistry reactions and these increases can damage mitochondria and genomic DNA as well as promote carcinogenesis. Accumulation of iron in the brain has been linked with aging, diet, disease, and cerebral hemorrhage. Further, deregulation of brain iron metabolism has been implicated in carcinogenesis and may be a contributing factor to the increased incidence of brain tumors around the world. Here, we provide insight into mechanisms by which iron accumulation in endolysosomes is altered by pH and lysosome membrane permeabilization. Such events generate excess ROS resulting in mitochondrial DNA damage, fission, and dysfunction, as well as DNA oxidative damage in the nucleus; all of which promote carcinogenesis. A better understanding of the roles that endolysosome iron plays in carcinogenesis may help better inform the development of strategic therapeutic options for cancer treatment and prevention.
AB - Iron, the most abundant metal in human brain, is an essential microelement that regulates numerous cellular mechanisms. Some key physiological roles of iron include oxidative phosphorylation and ATP production, embryonic neuronal development, formation of iron-sulfur clusters, and the regulation of enzymes involved in DNA synthesis and repair. Because of its physiological and pathological importance, iron homeostasis must be tightly regulated by balancing its uptake, transport, and storage. Endosomes and lysosomes (endolysosomes) are acidic organelles known to contain readily releasable stores of various cations including iron and other metals. Increased levels of ferrous (Fe2+) iron can generate reactive oxygen species (ROS) via Fenton chemistry reactions and these increases can damage mitochondria and genomic DNA as well as promote carcinogenesis. Accumulation of iron in the brain has been linked with aging, diet, disease, and cerebral hemorrhage. Further, deregulation of brain iron metabolism has been implicated in carcinogenesis and may be a contributing factor to the increased incidence of brain tumors around the world. Here, we provide insight into mechanisms by which iron accumulation in endolysosomes is altered by pH and lysosome membrane permeabilization. Such events generate excess ROS resulting in mitochondrial DNA damage, fission, and dysfunction, as well as DNA oxidative damage in the nucleus; all of which promote carcinogenesis. A better understanding of the roles that endolysosome iron plays in carcinogenesis may help better inform the development of strategic therapeutic options for cancer treatment and prevention.
KW - Brain
KW - Carcinogens
KW - Endolysosomes
KW - Iron
KW - ROS
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U2 - 10.1016/j.semcancer.2021.06.013
DO - 10.1016/j.semcancer.2021.06.013
M3 - Article
C2 - 34139350
AN - SCOPUS:85109081940
SN - 1044-579X
VL - 76
SP - 74
EP - 85
JO - Seminars in Cancer Biology
JF - Seminars in Cancer Biology
ER -