Mitochondrial DNA – role in cancer?

Mitochondria (plural of mitochondrion) are membrane-bound organelles (the cell’s ‘mini organs’) found in nearly all cells which play a vital role as “cellular power plants” by generating adenosine triphosphate (ATP), used by cells as a source of chemical energy. Mitochondria also play a role in cellular signaling, cellular differentiation, cell death, control of the cell cycle and cell growth, and other roles. Mitochondria are unusual in that they contain their own DNA, whilst the rest of the human genome is concentrated in the nucleus of the cell. Also, Mitochondrial DNA (mtDNA) is only inherited from mothers, whist the DNA in the cells nucleus is inherited from both mother and father.

Diagram of the structure of a mitochondrion from Wikimedia Commons under a Creative Commons CC0 license.

mtDNA has been linked carcinogenesis because of its high susceptibility to mutations and limited repair mechanisms in comparison to nuclear DNA. mtDNA lacks introns, so mutations tend to occur in coding sequences and it is thought that accumulation of these mutations may lead to tumor formation (Radpour et al, 2009). Research into of role of mtDNA mutations in cancer is advancing understanding of their functional role in carcinogenesis, value in diagnosis and monitoring, and potential therapeutic implications….

 

See more at:

http://www.cancerindex.org/geneweb/gmtdna.htm

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New insight into Prostate Cancer susceptibility

New research published in Nature Genetics (February 2014) by Qilai Huang and colleagues gives a new insight into the mechanisms by which men with a specific polymorphism (variation in a gene) have increased susceptibility to Prostate Cancer.

The team involving researchers in Finland, Sweden and China found that the ‘rs339331’ polymorphism is located  within a functional binding site of the HOXB13 gene and  causes an up regulation of RFX6, a protein which is associated with  prostate cancer cell proliferation, migration and invasion. Also, their analysis  of prostate tumours found a significant association between the T allele at rs339331 and higher levels of RFX6 mRNA.

For more details please see:

The CancerIndex page on the HOXB13 gene:

http://www.cancerindex.org/geneweb/HOXB13.htm

Nature Genetics:

Huang Q et al. A prostate cancer susceptibility allele at 6q22 increases RFX6 expression by modulating HOXB13 chromatin binding. Nature Genetics 46, 126–135 (2014)