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Nuclear genes involved in mitochondria-to-nucleus communication in breast cancer cells.

Delsite R, Kachhap S, Anbazhagan R, Gabrielson E, Singh KK - Mol. Cancer (2002)

Bottom Line: Expression of several genes was also down regulated.These include phospholipase C, agouti related protein, PKC gamma, protein tyrosine phosphatase C, phosphodiestarase 1A (cell signaling), PIBF1, cytochrome p450, (metabolism) and cyclin dependent kinase inhibitor p19, and GAP43 (cell growth and differentiation).These genes may mediate the cross talk between mitochondria and the nucleus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Sidney Kimmel Cancer Center, Johns Hopkins School of Medicine, Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Room 143, Baltimore, MD 21231, USA. RDELSITE@PARTNERS.ORG

ABSTRACT

Background: The interaction of nuclear and mitochondrial genes is an essential feature in maintenance of normal cellular function. Of 82 structural subunits that make up the oxidative phosphorylation system in the mitochondria, mitochondrial DNA (mtDNA) encodes 13 subunits and rest of the subunits are encoded by nuclear DNA. Mutations in mitochondrial genes encoding the 13 subunits have been reported in a variety of cancers. However, little is known about the nuclear response to impairment of mitochondrial function in human cells.

Results: We isolated a Rho0 (devoid of mtDNA) derivative of a breast cancer cell line. Our study suggests that depletion of mtDNA results in oxidative stress, causing increased lipid peroxidation in breast cancer cells. Using a cDNA microarray we compared differences in the nuclear gene expression profile between a breast cancer cell line (parental Rho+) and its Rho0 derivative impaired in mitochondrial function. Expression of several nuclear genes involved in cell signaling, cell architecture, energy metabolism, cell growth, apoptosis including general transcription factor TFIIH, v-maf, AML1, was induced in Rho0 cells. Expression of several genes was also down regulated. These include phospholipase C, agouti related protein, PKC gamma, protein tyrosine phosphatase C, phosphodiestarase 1A (cell signaling), PIBF1, cytochrome p450, (metabolism) and cyclin dependent kinase inhibitor p19, and GAP43 (cell growth and differentiation).

Conclusions: Mitochondrial impairment in breast cancer cells results in altered expression of nuclear genes involved in signaling, cellular architecture, metabolism, cell growth and differentiation, and apoptosis. These genes may mediate the cross talk between mitochondria and the nucleus.

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Lipid peroxidation is increased due to dysfunction in mitochondria: Subconfluent cultures were collected by trypsinization, washed with ice cold PBS and lysed by freeze/thaw cycles in sterile deionized water. Lipid peroxidation was measured as described in material methods.
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Figure 4: Lipid peroxidation is increased due to dysfunction in mitochondria: Subconfluent cultures were collected by trypsinization, washed with ice cold PBS and lysed by freeze/thaw cycles in sterile deionized water. Lipid peroxidation was measured as described in material methods.

Mentions: Mitochondria are the major site of reactive oxygen (ROS) production [1,2] OS cause oxidative damage. It is conceivable that altered mitochondrial function in Rho0 leads to increased oxidative stress. We therefore measured lipid peroxidation in parental and Rho0 breast cancer cells. Malondialdehyde, a product of the catabolism of peroxidized lipids, forms a pigmented reaction product with thiobarbituric acid that can be measured spectrophotometrically [10,11]. Levels of thiobarbituric acid-reactive species were measured in extracts of parental Rho+ and Rho0 cells to determine if altered mitochondrial function results in lipid peroxidation. Figure 4 shows that thiobarbituric acid-reactive species were increased in Rho0 cells (solid bar) compared to the Rho+ parental cells (open bar). We conclude that an increase in lipid peroxidation is associated with the impairment of mitochondrial function.


Nuclear genes involved in mitochondria-to-nucleus communication in breast cancer cells.

Delsite R, Kachhap S, Anbazhagan R, Gabrielson E, Singh KK - Mol. Cancer (2002)

Lipid peroxidation is increased due to dysfunction in mitochondria: Subconfluent cultures were collected by trypsinization, washed with ice cold PBS and lysed by freeze/thaw cycles in sterile deionized water. Lipid peroxidation was measured as described in material methods.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC149409&req=5

Figure 4: Lipid peroxidation is increased due to dysfunction in mitochondria: Subconfluent cultures were collected by trypsinization, washed with ice cold PBS and lysed by freeze/thaw cycles in sterile deionized water. Lipid peroxidation was measured as described in material methods.
Mentions: Mitochondria are the major site of reactive oxygen (ROS) production [1,2] OS cause oxidative damage. It is conceivable that altered mitochondrial function in Rho0 leads to increased oxidative stress. We therefore measured lipid peroxidation in parental and Rho0 breast cancer cells. Malondialdehyde, a product of the catabolism of peroxidized lipids, forms a pigmented reaction product with thiobarbituric acid that can be measured spectrophotometrically [10,11]. Levels of thiobarbituric acid-reactive species were measured in extracts of parental Rho+ and Rho0 cells to determine if altered mitochondrial function results in lipid peroxidation. Figure 4 shows that thiobarbituric acid-reactive species were increased in Rho0 cells (solid bar) compared to the Rho+ parental cells (open bar). We conclude that an increase in lipid peroxidation is associated with the impairment of mitochondrial function.

Bottom Line: Expression of several genes was also down regulated.These include phospholipase C, agouti related protein, PKC gamma, protein tyrosine phosphatase C, phosphodiestarase 1A (cell signaling), PIBF1, cytochrome p450, (metabolism) and cyclin dependent kinase inhibitor p19, and GAP43 (cell growth and differentiation).These genes may mediate the cross talk between mitochondria and the nucleus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Sidney Kimmel Cancer Center, Johns Hopkins School of Medicine, Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Room 143, Baltimore, MD 21231, USA. RDELSITE@PARTNERS.ORG

ABSTRACT

Background: The interaction of nuclear and mitochondrial genes is an essential feature in maintenance of normal cellular function. Of 82 structural subunits that make up the oxidative phosphorylation system in the mitochondria, mitochondrial DNA (mtDNA) encodes 13 subunits and rest of the subunits are encoded by nuclear DNA. Mutations in mitochondrial genes encoding the 13 subunits have been reported in a variety of cancers. However, little is known about the nuclear response to impairment of mitochondrial function in human cells.

Results: We isolated a Rho0 (devoid of mtDNA) derivative of a breast cancer cell line. Our study suggests that depletion of mtDNA results in oxidative stress, causing increased lipid peroxidation in breast cancer cells. Using a cDNA microarray we compared differences in the nuclear gene expression profile between a breast cancer cell line (parental Rho+) and its Rho0 derivative impaired in mitochondrial function. Expression of several nuclear genes involved in cell signaling, cell architecture, energy metabolism, cell growth, apoptosis including general transcription factor TFIIH, v-maf, AML1, was induced in Rho0 cells. Expression of several genes was also down regulated. These include phospholipase C, agouti related protein, PKC gamma, protein tyrosine phosphatase C, phosphodiestarase 1A (cell signaling), PIBF1, cytochrome p450, (metabolism) and cyclin dependent kinase inhibitor p19, and GAP43 (cell growth and differentiation).

Conclusions: Mitochondrial impairment in breast cancer cells results in altered expression of nuclear genes involved in signaling, cellular architecture, metabolism, cell growth and differentiation, and apoptosis. These genes may mediate the cross talk between mitochondria and the nucleus.

Show MeSH
Related in: MedlinePlus