Single nucleotide polymorphisms in the mitochondrial displacement loop and age at onset of non-Hodgkin lymphoma

Polymorphisms of mitochondrial DNA control region are associated to endometriosis

PURPOSE

Polymorphisms in the control region of mitochondrial DNA (mtDNA) can affect generation of reactive oxygen species and impact in the pathogenesis of endometriosis. This study investigated the association of mtDNA polymorphisms with endometriosis.

METHODS

Patients were divided in two groups: endometriosis (n = 90) and control (n = 92). Inclusion criteria were as follows: women between 18 and 50 years, with histological diagnosis and surgical staging of endometriosis (endometriosis group) or undergoing gynecological surgery for tubal ligation, leiomyoma, or ovarian cysts, with no evidence of endometriosis (control group). DNA extraction was performed from peripheral blood. Sanger sequencing of mtDNA control region was performed, and polymorphisms were determined comparing the sequences obtained with the Cambridge Reference Sequence.

RESULTS

The frequency of polymorphisms T16217C (14.4 and 5.4% of endometriosis and control group, respectively; p = 0.049) and G499A (13.3 vs. 4.3%; p = 0.038) was higher in the endometriosis group, while T146C (32.6 vs. 18.9%; p = 0.042) and 573.2C (5.6 vs. 29.3%; p < 0.001) were lower. No difference was observed in haplogroups between groups.

CONCLUSION

mtDNA polymorphisms T16217C and G499A were associated with endometriosis, while T416C and 573.2C were shown to be associated with an absence of disease.

Identification of sequence polymorphisms in the mitochondrial cytochrome c oxidase genes as risk factors for hepatocellular carcinoma

BACKGROUND

Single nucleotide polymorphisms (SNPs) accumulated in the mitochondrial DNA (mtDNA) is susceptible to the tumor formation. We discovered previously that SNPs in the mitochondrial displacement loop (D-loop) was associated with the risk of hepatocellular carcinoma (HCC).

METHODS

The cytochrome c oxidase (COX) genes of mtDNA were sequenced between 107 HCC patients and 100 matched healthy controls. The χ² test was used to analyze single SNPs' statistical difference between HCC patients and healthy controls.

RESULTS

In this study, cancer risk-associated SNPs in the COX genes of mtDNA coding region were assessed in HCC patients and health controls. The nucleotide position at site 9545A/G (P=.036) was identified its association for HCC with the 9545G allele susceptible to cancer risk.

CONCLUSIONS

The SNPs in the COX genes may help us to evaluate the cancer risk of HCC.