Abstract: MDR bacteria including carbapenem-resistant Pseudomonas aeruginosa are recognized as an important cause of hospital-acquired infections worldwide. This investigation seeks to determine the molecular characterization and antibiotic resistance genes associated with carbapenem-resistant P. aeruginosa. Methods We conducted WGS and phylogenetic analysis of 72 carbapenem-resistant P. aeruginosa isolated from hospital-acquired infection patients from August 2011 to March 2015 in three major hospitals in Hanoi, Vietnam. Results We identified three variants of IMP gene, among which blaIMP-15 was the most frequent (n = 34) in comparison to blaIMP-26 (n = 2) and blaIMP-51 (n = 12). We observed two isolates with imipenem MIC & gt;128 mg/L that co-harboured blaIMP-15 and blaDIM-1 genes and seven isolates (imipenem MIC  & gt; 128 mg/L) with a blaKPC-1 gene from the same hospital. MLST data shows that these 72 isolates belong to 18 STs and phylogenetic tree analysis has divided these isolates into nine groups. Conclusions Our results provide evidence that not only blaIMP-26 but other IMP variants such as blaIMP-15 and blaIMP-51 genes and several STs (ST235, ST244, ST277, ST310, ST773 and ST3151) have been disseminating in healthcare settings in Vietnam. In addition, we report the emergence of two isolates belonging to ST1240 and ST3340 that harboured two important carbapenemase genes (blaIMP-15 and blaDIM-1) and seven isolates belonging to ST3151 of P. aeruginosa that carried the blaKPC-1 gene in Vietnam, which could potentially cause serious restricted availability of treatment options in healthcare settings.

Abstract: For the prevalence of lung cancer and its poor diagnosis, the seeking of the efficient biomarkers for this disease is an urgent requirement, especially from non-invasive samples such as plasma. The mitochondria DNA (mtDNA) copy number change has been evaluated as a potential indicator of cancer risk, however, there have been few studies regarding mtDNA in plasma derived exosomes. In this study, the mtDNA copy number was measured on 29 plasma exosome samples of patients with non-small cell lung cancer (NSCLC) and 29 plasma exosome samples of cancer-free controls by real-time PCR assay, then being statistically analyzed to evaluate the relationship between these figures and several pathological features of NSCLC patients. As the results, the existence of mtDNA in exosomes isolated from plasma was detected through PCR assay using primers covering most of the mtDNA length. The relative mtDNA copy numbers determined in the exosomes of the disease and control groups were 1619.1 ± 2589.0 and 1207.0 ± 1550.0, respectively, whereas these values in two disease stages were 783.6 ± 759.3 (stage I-II) and 2647.0 ± 3584.0 (stage III-IV). Comparing among these groups, the difference was only statistically significant between the disease groups of stage I-II and stage III-IV (p 〈 0.05), the group of stage III-IV and the control group (p 〈 0.05). Indeed, the mtDNA copy number is associated with tumor stage and stage N (p 〈 0.05). On the other aspect, the smoking habit of NSCLC patients could be an underlying reason behind the alteration in mtDNA copy number in the plasma exosomes. In short, our study demonstrates that the mtDNA copy number in exosomes resourced from plasma could be a potential biomarker for the detection and prognosis of NSCLC.

Abstract: The MT-ATP8 gene encodes for A6L protein subunit belonging to the proton channel of the ATP synthase. MT-ATP8 gene’s mutations can affect the structure and function of the ATP synthase, which may cause diseases. In this study, alterations of MT-ATP8 gene were investigated in tumor tissues of patients with breast cancer and control blood samples using PCR combined with direct sequencing and PCR-RFLP methods, data were analyzed using bioinformatics tools and statistical methods. Sequencing results revealed 5 variants of MT-ATP8 gene on 35 breast tumor tissues and 26 blood samples of controls, of which two mutations C8414T and C8417T altered the amino acid sequence of the resulting protein. The C8417T was further screened by PCR-RFLP and was found in 0,98% (1/102) of breast tumor samples. This change lead to substitution of lecine to phenylalanine (L18F) in a highly conserved position of A6L and was predicted as probably damaging to the structure and function of the protein. Additionally, a 9 bp deletion was also observed in a non-coding region of mtDNA in 26,5% (27/102) of breast cancer patients and 27% (7/26) of controls. Thus, these results showed that C8417T variant in the conserved position of MT-ATP8 gene was rare and first identified in a group of breast cancer patients in Vietnam. Keywords Breast cancer, mitochondrial DNA, MT-ATP8 References [1] Petros JA, Baumann AK, Ruiz-Pesini E, Amin MB, Sun CQ, Hall J, Lim S, Issa MM, Flanders WD, Hosseini SH, Marshall FF, Wallace DC, mtDNA mutations increase tumorigenicity in prostate cancer, Proc Natl Acad Sci U S A (2005), 102(3):719-24.[2] Wang X, The expanding role of mitochondria in apoptosis, Genes Dev (2001), 15(22):2922-33.[3] Jonckheere AI, Smeitink JA, Rodenburg RJ, Mitochondrial ATP synthase: architecture, function and pathology, J Inherit Metab Dis (2012), 35(2):211-25.[4] Grzybowska-Szatkowska L, Slaska B, Rzymowska J, Brzozowska A, Florianczyk B, Novel mitochondrial mutations in the ATP6 and ATP8 genes in patients with breast cancer, Mol Med Rep (2014), 10(4):1772-8.[5] Adzhubei IA, Schmidt S, Peshkin L, Ramensky VE, Gerasimova A, Bork P, Kondrashov AS, Sunyaev SR, A method and server for predicting damaging missense mutations, Nat Methods (2010), 7(4):248-9.[6] Thapa S, Lalrohlui F, Ghatak S, Zohmingthanga J, Lallawmzuali D, Pautu JL, Senthil Kumar N, Mitochondrial complex I and V gene polymorphisms associated with breast cancer in mizo-mongloid population, Breast Cancer (2016), 23(4):607-16.[7] Warburg O, On the origin of cancer cells , Science (1956), 123:309-14.[8] Dumas JF, Rousse D, Servais S, Mitochondria and cancer, Cellular Bioenergetics in Health and Diseases: New Perspectives in Mitochondrial Biology (2012), 115-47.[9] Mkaouar-Rebai E, Kammoun F, Chamkha I, Kammoun N, Hsairi I, Triki C, Fakhfakh F, A de novo mutation in the adenosine triphosphatase (ATPase) 8 gene in a patient with mitochondrial disorder, J Child Neurol (2010), 25(6):770-5.[10] Jonckheere AI, Hogeveen M, Nijtmans LG et al., A novel mitochondrial ATP8 gene mutation in a patient with apical hypertrophic cardiomyopathy and neuropathy, J Med Genet (2008), 45:129-33.[11] Ware SM, El-Hassan N, Kahler SG et al., Infantile cardiomyopathy caused by a mutation in the overlapping region of mitochondrial ATPase 6 and 8 genes, J Med Genet (2009), 46:308-14.[12] Liu VW, Shi HH, Cheung AN, Chiu PM, Leung TW, Nagley P, Wong LC, Ngan HY, High incidence of somatic mitochondrial DNA mutations in human ovarian carcinomas, Cancer Res (2001), 61(16):5998-6001.[13] Zhuo G, Feng G, Leng J, et al., A 9-bp deletion homoplasmy in women with polycystic ovary syndrome revealed by mitochondrial genome-mutation screen, Biochem Genet (2010), 48:157-163.[14] Abu-Amero KK, Alzahrani AS, Zou M, Shi Y, Association of mitochondrial DNA transversion mutations with familial medullary thyroid carcinoma/multiple endocrine neoplasia type 2 syndrome, Oncogene (2006), 25:677-84.[15] Bonora E, Porcelli AM, Gasparre G, et al., Defective oxidative phosphorylation in thyroid oncocytic carcinoma is associated with pathogenic mitochondrial DNA mutations affecting complexes I and III, Cancer Res (2006), 66:6087-96.[16] Costa-Guda J, Tokura T, Roth SI, Arnold A, Mitochondrial DNA mutations in oxyphilic and chief cell parathyroid adenomas, BMC Endocr Disord (2007); 7:8.[17] Chintha R, Kaipa PR, Sekhar N, Hasan Q, Mitochondria and tumors: A new perspective, Indian J Cancer (2013), 50(3).[18] Tan DJ, Bai RK, Wong LJ, Comprehensive scanning of somatic mitochondrial DNA mutations in breast cancer, Cancer Res (2002), 62(4):972-6.[19] Tipirisetti NR, Lakshmi RK, Govatati S, Govatati S, Vuree S, Singh L, Raghunadha Rao D, Bhanoori M, Vishnupriya S, Mitochondrial genome variations in advanced stage breast cancer: a case-control study, Mitochondrion (2013), 13(4):372-8. [20] Ghaffarpour M, Mahdian R, Fereidooni F, Kamalidehghan B, Moazami N, Houshmand M, The mitochondrial ATPase6 gene is more susceptible to mutation than the ATPase8 gene in breast cancer patients, Cancer Cell Int (2014), 14(1):21.[21] Perucca-Lostanlen D, Narbonne H, Hernandez JB, et al., Mitochondrial DNA variations in patients with maternally inherited diabetes and deafness syndrome, Biochem Biophys Res Commun (2000), 277(3):771-5.[22] Bai Y, Guo Z, Xu J, Zhang J, Cui L, Zhang H, Zhang S, The 9-bp deletion at position 8272 in region V of mitochondrial DNA is associated with renal cell carcinoma outcome, Mitochondrial DNA A DNA Mapp Seq Anal (2014), 27(3):1973-5.[23] Jin Y, Yu Q, Zhou D, Chen L, Huang X, Xu G, Huang J, Gao X, Gao Y, Shen L, The mitochondrial DNA 9-bp deletion polymorphism is a risk factor for hepatocellular carcinoma in the Chinese population, Genet Test Mol Biomarkers (2012), 16(5):330-4.[24] Ren W, Li Y, Li R, Feng H, Wu S, Mao Y, Huang L, Mitochondrial intergenic COII/tRNA(Lys) 9-bp deletion, a biomarker for hepatocellular carcinoma? Mitochondrial DNA A DNA Mapp Seq Anal (2015), 27(4):2520-2.[25] Cortopassi GA, Shibata D, Soong NW, Arnheim N, A pattern of accumulation of a somatic deletion of mitochondrial DNA in aging human tissues, Proc Natl Acad Sci U S A (1992), 89(16):7370-4.

Abstract: Some mutations of mt-DNA which encode tRNA (mt-tRNA) were previously reported  to be associated with clinical manifestations of neuromuscular disorders syndrome. In addition, alterations of the mitochondrial genome have been suggested to contribute to mitochondrial dysfunction and tumorigenesis. Alterations in some mt-tRNA genes have also been identified in breast cancer, lung cancer and colorectal cancer. However, so far, we have not found any report on mt-tRNA gene alteration in the Vietnamese colorectal cancer patients. So that, in this study, we analyzed the alterations of some mt-tRNA genes in a group of  Vietnamese colorectal cancer patients and predicted influence of the alterations to secondary structure of tRNA based on bioinformatic tools. PCR-RFLP and DNA sequencing methods were used to screening alterations, secondary structure of tRNA was predicted in silico by using a tool of the  Vienna RNA Websuite. Results: both A12309G and A12310G of tRNALeu were identified together in two out of 98 patients, and both T12150G and C12154G of tRNAHis were indentified in one  out of 19 patients. All of these alterations were heteroplasmic and have not been reported in cancer patients. In particular, the C12154G  alteration in the DHR loop led to change of secondary structure of  tRNAHis and may affect to function of this tRNA molecule. Keywords mt-tRNA, Vietnamese colorectal cancer, PCR-RFLP, DNA sequencing References [1] http://globocan.iarc.fr/Pages/online.aspx (30/11/2017).[2] M. Brandon, P. Baldi, D.C Wallace, Mitochodrial mutations in cancer, Oncogen 25(34) (2006) 4647.[3] G. Li, YX. Duan, XB. Zhang, F Wu, Mitochondrial RNA mutations may be infrequent in hepatocellular carcinoma patients, Genet Mol Res15(2) (2016) doi: 10.4238/gmr.15027665.[4] F. Mohammed, AR. Rezaee, E. Mosaieby, M. Houshmand, Mitochondrial A12308G alteration in RNA Leu (CUN)) in colorectal cancer samples, Diagn Pathol (2015) doi: 10.1186/s13000-015-0337-6.[5] S. Datta, M. Majumder, NK. Biswas, N. Sikdar, B. Roy, Increased risk of oral cancer in relation to common Indian mitochondrial polymorphisms and Autosomal GSTP1 locus, Cancer, 110 (2007) 1999.[6] L .Wang , ZJ. Chen , YK. Zhang , HB. Le, The role of mitochondrial RNA mutations in lung cancer, Int J Clin Exp Med 8(8) (2015) 13341.[7] AR. Gruber, R. Lorenz, SH. Bernhart, R. Neubock, IL Hofacker The Vienna ARN Websuite, Nucleic Acids Res 36 (2008) 70.[8] https://blast.ncbi.nlm.nih.gov/Blast.cgi (11/2017).[9] Y. Goto, I Nonaka, S Horai, A mutation in the RNALeu (UUR) gene associated with the MELAS subgroup of mitochondrial encephalomyopathies, Nature 348(6302 (1990) 651[10] http://www.mitomap.org/MITOMAP (11/2017).[11] A. Lorenc, J. Bryk Golik P, Homoplasmic MELAS A3243G mtDNA mutation in a colon cancer sample, Mitochondrion 3(2) (2003) 119.[12] EL. Blakely, J.W Yarham , C.L. Alston , K Craig , J. Poulton , C. Brierley , SM. Park , A. Dean , JH. Xuereb , KN. Anderson , A. Compston , C. Allen , S. Sharif , P. Enevoldson , M. Wilson , SR. Hammans , DM. Turnbull , R. McFarland , RW.Taylor , Pathogenic mitochondrial tRNA point mutations: nine novel mutations affirm their importance as a cause of mitochondrial disease, Hum Mutat 34(9) (2013) 1260.[13] S. DiMauro, Mitochondrial ADN medicine, Biosci Rep 27(3) (2007) 5.[14] DC. Wallace, D. Chalkia, Mitochondrial ADN genetics and the heteroplasmy conundrum in evolution and disease”, Cold Spring Harb Perspect Biol 5(11) (2013), doi:10.1101/cshperspect. a021220  

Abstract: Mục tiêu: Nhằm đánh giá khả năng xác định chuỗi nhẹ tự do trong bệnh viêm não tự miễn, nghiên cứu đã sử dụng phương pháp thẩm tách miễn dịch để phân tích chuỗi nhẹ tự do kappa và lamda trong dịch não tủy và huyết tương của bệnh nhân. Đối tượng nghiên cứu: gồm 9 cặp mẫu huyết tương và dịch não tuỷ của 9 bệnh nhân được chẩn đoán viêm não tự miễn do Bệnh viện Nhi Trung ương cung cấp. Phương pháp nghiên cứu: Albumin và IgG được phân đoạn bằng sắc ký ái lực, và được phân tách bằng điện di 2 chiều. Chuỗi nhẹ tự do kappa và lamda được xác định bằng phương pháp thẩm tách miễn dịch, sau đó được định lượng bằng phần mềm ImageJ. Kết quả: Albumin và IgG là 2 thành phần chủ yếu của huyết tương, chúng gồm nhiều dạng isotype được phân tách thành các dải spot trên bản gel điện di 2 chiều. Chuỗi nhẹ tự do kappa biểu hiện rõ rệt trong tất cả 9 mẫu dịch não tuỷ và huyết tương. Không thấy xuất hiện chuỗi nhẹ tự do lamda trong dịch não tuỷ của bệnh nhân. Kết luận: Chuỗi nhẹ tự do kappa biểu hiện mạnh trong mẫu dịch não tuỷ và phương pháp thẩm tách miễn dịch là phương pháp tiềm năng có thể được phát triển để sử dụng trong xét nghiệm hỗ trợ chẩn đoán bệnh viêm não tự miễn. Từ khóa: Chuỗi nhẹ tự do, bệnh viêm não tự miễn, đa xơ cứng, dịch não tuỷ