Mitochondrial DNA Copy Number in Colorectal Cancer in Vietnamese Patients

Mitochondria are organelles present in most eukaryotic cells, have their own genome and replicate independently of the nuclear genome. Alterations of mitochondrial DNA (mtDNA) have been shown to be associated with cancer. In particular, each cell has many mtDNA copies, the copy number depends on the cell type and the pathological state of the cell. To understand the role of mtDNA copy number in colorectal cancer (CRC), we quantified mtDNA copy number using real-time PCR method on 115 pairs of cancer tissue samples and 40 blood samples of CRC patients which were provided by hospital K, Military Hospital 103 and 67 blood samples of healthy people were used as controls. The results showed that, on tissue samples, most patients had mtDNA copy numbers in the range of 500-1500. The mtDNA copy number in the tissue sample of colon cancer patients (median: 1487.90) was higher than that of rectal cancer patients (median: 694.84) (p<0.05). The mtDNA copy number tends to increase with age, women are higher than men, and decreases with lymph node metastasis and cancer stage. The mtDNA copy number of blood samples from cancer patients is 3.4 times higher than that of blood samples from healthy people (p<0.05). The correlation of mtDNA copy number between tissue and blood samples from the same cancer patient is weak.