Mitochondrial DNA copy number and hnRNP A2/B1 protein: Biomarkers for direct exposure of benzene

Abstract

The present study was performed to identify biomarkers for exposure of benzene in blood cells and hematopoietic tissues. Peripheral mononuclear cells, hematopoietic stem cells, and leukemia cell lines were cultured in RPMI 1640 media with the addition of 0, 1, and 10 mM of benzene. Hydrogen peroxide was measured using an enzyme immunoassay. Mitochondrial mass, membrane potential, and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green/Red probes, and real-time polymerase chain reaction. In addition, two-dimensional gel electrophoresis and mass spectrometry matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology were performed to identify protein markers. The mitochondrial contents and membrane potentials were dramatically increased after three weeks of direct benzene exposure. The hydrogen peroxide level increased significantly after two weeks of treatment with benzene (4.4 ± 1.9 µM/mg protein) compared to the non-benzene treatment group (1.2 ± 1.0; p = 0.001). The mtDNA copy number gradually increased after exposure to benzene. Numerous protein markers showed significant aberrant expression after exposure to benzene. Among them, the heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 was markedly decreased after exposure to benzene. Thus, increased mitochondrial mass, mtDNA copy number, and the hnRNP A2/B1 protein were biomarkers for benzene-related toxicity and hematotoxicity.

Profiling of Biomarkers for the Exposure of Polycyclic Aromatic Hydrocarbons: Lamin-A/C Isoform 3, Poly[ADP-ribose] Polymerase 1, and Mitochondria Copy Number Are Identified as Universal Biomarkers

“…mtDNA copy number was determined according to our published protocol [13]. For in vitro model study, the purified PCR product of cytochrome b (Cytb) gene was inserted into pGEM-T easy vector and E. coli JM 109 cells (Promega, Madison, WI, USA) were transformed in order to obtain recombinant plasmids.…”

“…This study used a published protocol to amplify and sequence the mtDNA control region gene and minisatellites (303 poly C, 16189 poly C and 514 (CA) repeat) [13]. The mtDNA sequences obtained were analyzed using the Revised Cambridge Reference Sequence (http://www.mitomap.org/), Blast2 program (http://www.ncbi.nlm.nih.gov/blast/bl2seq/wblast2.cgi), and the MitoAnalyzer (http://www.cstl.nist.gov/biotech/strbase/mitoanalyzer.html) to identify mtDNA aberrations.…”

“…Past evidence had indicated that the mtDNA repair capacity is limited and that the proximity of mtDNA to sites of reactive oxygen species generation suggested that mtDNA may be more susceptible to mutation than nuclear DNA. Our laboratory has recently reported that hnRNP protein and the change of mitochondrial genome are recognized as novel and useful markers for benzene exposure [13]. Moreover, there is currently a paucity of data on the direct effects of PAHs in primary hematopoietic cells and various cell lines.…”

Mitochondria malfunctions as mediators of stem-cells’ related carcinogenesis: A hypothesis that supports the highly conserved profile of carcinogenesis

“…Mitochondrial DNA is highly susceptible to damage [29,30] while several carcinogenic chemical compounds (e.g. polycyclic aromatic hydrocarbons, azo dyes and nitrosamines), accumulate preferentially in mtDNA than in nuclear DNA highlighting the role of mtDNA mutations in chemical carcinogenesis [31][32][33].…”

Helicobacter pyloriouter inflammatory protein A (OipA) suppresses apoptosis of AGS gastric cells in vitro

“…Non-gastric cancer HNRNPA2B1used as marker for detection of lung cancer (Eom et al, 2011). (Leiblich et al, 2006;Luo et al, 2015;McCleland et al, 2013;Rodriguez et al, 2003).…”