ARTICLE | doi:10.20944/preprints202208.0337.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: breast cancer; polymorphism; mitochondrial genomics; D310
Online: 18 August 2022 (10:17:28 CEST)
Breast cancer has an important incidence in the worldwide female population. Although alterations in the mitochondrial genome probably play an important role in carcinogenesis, the actual evidence is ambiguous and inconclusive. The purpose of the present work was to explore mitochondrial sequences of clinical cases with breast cancer from different origins and determine the polymorphisms associated. The search for complete and partial mtDNA sequences obtained from breast cancer patients and controls was performed in NCBI Genbank database. We identified 124 mtDNA sequences associated to breast cancer cases of which 86 were complete and 38 partial sequences. Of these 86 complete sequences, 52 belong to patients with a confirmed diagnosis of breast cancer and 34 sequences were obtained from healthy mammary tissue of the same patients used as controls. From mtDNA analysis, two polymorphisms with significative statistical differences were found in D130 in sequences analyzed: m.310del (rs869289246) in 34.6% (27/78) breast cancer cases and 61.7% (21/34) of controls; and m.315dup (rs369786048) in 60.2% (47/78) of breast cancer cases and 38.2% (13/34) of controls. Also, the variant m.16519T>C (rs3937033) was found in 59% of control sequences and 52% of breast cancer sequences with a significant statistical difference. Polymorphic changes are evolutionarily related to haplogroup H of Indo-European and Euro Asiatic origins, however, were found in all non-European sequences with breast cancer.
ARTICLE | doi:10.20944/preprints202210.0025.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mitochondria; Type 2 diabetes; MDP; MOTS-c; Humanin; SHLP
Online: 5 October 2022 (03:43:17 CEST)
Since the discovery of mitochondrial-derived peptides (MDP), their participation in cellular metabolism is no longer considered as the sole function of the mitochondria, but importance was also attached to its role as a source of protective factors of metabolic stress. These peptides are encoded in the mitochondrial genome and translated into the mitochondria or cytoplasm, to signal within the cell or be released and bind to membrane receptors. The objective of this work was explored and compare the frequency of MT-RNR1 and MT-RNR2 variants in sequences obtained from T2D individuals and control population. 213 different mitochondrial polymorphisms previously reported in the literature associated with T2D and cardiovascular diseases were analyzed. We can found three variants in the MT-RNR1 not related with MOTS-c coding sequence: m.1189T>C (rs28358571), m.1420T>C (rs111033356), and m.1438A>G (rs2001030); and secondly, three polymorphisms associated to MT-RNR2 m.2667T>C (rs878870626) related to humanin, m.1811A>G (rs28358576) in SHPL3 and m.3027T>C (rs199838004) in SHPL6 associated with statistical differences between the T2D and control group. All these findings were previously related to cardiovascular complications in literature and, as far as we know, relating for the first time in diabetic patients.
ARTICLE | doi:10.20944/preprints202309.0086.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: mtDNA; mitogenome; Type 2 diabetes; polymorphism; SNP
Online: 5 September 2023 (10:22:58 CEST)
Type 2 diabetes (T2D) is a chronic systemic disease with a complex etiology, characterized by insulin resistance and mitochondrial dysfunction in various cell tissues. To explore this relationship, we conducted a secondary analysis of complete mtDNA sequences from 1,261 T2D patients and 1,105 control individuals. Our findings revealed significant associations between certain single nucleotide polymorphisms (SNPs) and T2D. Notably, the variants m.1438A>G (controls: 32 [27.6%], T2D: 84 [72.4%]; OR: 2.46; 95%CI: 1.64-3.78; p<0.001), m.14766C>T (controls: 498 [36.9%], T2D: 853 [63.1%]; OR: 2.57, 95%CI: 2.18-3.04, p<0.001), and m.16519T>C (controls: 363 [43.4%], T2D: 474 [56.6%]; OR: 1.24, 95%CI: 1.05-1.47, p=0.012) were significantly associated with diabetes probability. The variant m.16189T>C Previously reported in multiple studies in different populations, it was not found to be associated with T2D in our analysis (controls: 148 [13.39] T2D: 171 [13.56%]; OR: 1.03; 95%CI: 0.815-1.31,; p=0.83). These results provide evidence suggesting a link between some mtDNA polymorphisms and T2D, probably related to association rules and topological patterns and three-dimensional confirmation associated to regions where the changes are, rather than to point mutations in the sequence.