HYPERMETHYLATED DNA AS BIOMARKER FOR NASOPHARYNGEAL CANCER DETECTION

Backgroud: Nasopharyngeal carcinoma (NPC) is a malignancy with remarkable geographic and distribution worldwide, toward in Southern China and Southern Asia. In addition to Epstein–Barr virus infection, environmental carcinogens, the development of NPC involves the cumulative genetic as well as epigenetic alteration. More recently, it has been reported that DNA hypermethylation, an epigenetic mechanism, that occurred by the addition of a methyl group at 5' position of the pyrimidine ring of cytosine residues at CpG islands, has been considered as the cause of nasopharyngeal tumorigenesis. In recent years, many reports have focused on the identification, evaluation of aberrant methylation of target tumor suppressor genes' promoters, such as RASSF1A, BLU, DLEC, RARβ, p16, p15, p14, and MGMT in the NPC development.Objective: We focused on the description and exemplification of the DNA hypermethylation changes in nasopharyngeal carcinoma.Conclusion: we highlighted the DNA hypermethylation as a potential biomarker applied in monitoring, screening, and early diagnosis for cancer of nasopharynx

Epidemiology, incidence and mortality of Nasopharynx Cancer in Southeast Asia: an update report

Background: Nasopharyngeal cancer, with a distinct geographical and racial distribution, is the common neck and head cancer. Knowledge about the ecological factors including incidence, mortality, and so on, is important to find out the best way for its prevention in future. The aim of current study was to find out the incidence(-ASR), mortality(-ASR) of nasopharyngeal cancer and its correlation between those factors with HDI as well as its components in Southeast Asian countries in 2018.Methods: The data of the incidence(-ASR), mortality(-ASR), Human development index (HDI) were extracted from the GLOBOCAN project and Human Development Reports database. The relationships were evaluated by using Pearson Correlation Coefficient method.Results: In Southeast Asian region, incidence of 34,681, and mortality of 22,231 were recorded. The high incidence and mortality were related to medium human development countries. The significant positive correlations were observed between HDI with incidence-ASR (r = 6.25, p = 0.04) and mortality-ASR (r = 0.38, p = 0.26). No significant correlations were found between HDI component with incidence-ASR and mortality-ASR, except for the relationship between incidence-ASR and GNI/capita (r = 0.71, p = 0.02).Conclusion: The nasopharyngeal cancer is native to Asian region, includes Southeast Asian countries. The highest incidence and mortality were recorded in medium HDI countries.Keywords: Nasopharyngeal cancer; Epidemiology; Ecology, Southeast Asi

DNA Hypermethylation in Breast Cancer

Cancer development is a complex process with multiple steps. Many factors, including radiation, chemicals, viruses, genetic and epigenetic changes, lead to abnormal proliferation of a single cell, which results in the outgrowth of a population of clonal-derived tumour cells. It has established that DNA hypermethylation, an epigenetic mechanism that occurred by the addition of a methyl group at 5′ position of the pyrimidine ring of cytosine residues at CpG islands through the action of DNA methyltransferase enzymes, has been considered as the cause of human tumorigenesis, including breast cancer development. Moreover, DNA hypermethylation holds a promising application as a potential biomarker for the early detection, prognosis and prediction of drug sensitivity in cancer. Therefore, this chapter focuses on the description and exemplification of the DNA hypermethylation changes, particularly, highlight the DNA hypermethylation as a potential biomarker applied in predictive, diagnostic, prognostic and therapeutic monitoring of breast cancer

IDENTIFICATION OF FREQUENT PROMOTER METHYLATION OF DEATH-ASSOCIATED PROTEIN KINASE IN LIQUID-BASED PAPANICOLAOUS TEST SAMPLES IN VIETNAMESE POPULATION

  Objective: The infection of high-risk human papillomavirus (HPV) genotypes, particularly HPV-16 and HPV-18, is known to cause cervical cancer (CC); however, aberrant DNA methylation of death-associated protein kinase (DAPK), a member of tumor suppressor gene family, are required for cervical tumorigenesis. The aim of our study was to evaluate the hypermethylation frequency of CpG belonged to DAPK promoter, in Vietnamese patients, as well as to study about the association between hypermethylation, and high-risk HPV infection leading to CC.Methods: Methylation-specific-polymerase chain reaction (MSP) was performed to analyze methylation status from 109 liquid-based papanicolaous test samples, collected from local hospital and were identified whether HPV/or non-HPV, high-risk/low-risk HPV infection, then was confirmed by sequencing.Results: In the case of high-risk HPV infection, the frequency of DAPK gene hypermethylation was 66.67% (24 of 36 cases). Meanwhile, low hypermethylation status was found in low-risk and non-HPV infection, counting for 12.0% (3 of 25 cases), 2.1% (1 of 48 cases), respectively. Significant association of DAPK hypermethylation with high-risk, low-risk, and non-HPV infection was observed (p<0.0001). The DAPK hypermethylation increased the possibility to CC in the case of high-risk HPV infected with high incidence: Odds ratio=34.5 (95% confidence interval [CI]=10.15-117.23, p<0.01), relative risk=12.2 (95% CI=4.56-32.42, p<0.01).Conclusion: Based on those data, it suggested that MSP carried out on noninvasive samples will lead to potential method to screening, diagnosis and early diagnosis of cervical carcinoma in Vietnamese population

Effect of plant growth regulators on growth and lipid accumulation of microalgal Haematococcus pluvialis Flotow in two-stage culture

Haematococcus pluvialis cells were cultured in aerated liquid Bold’s Basal medium in two-stage (initial stage during in 7 weeks for increased biomass growth and second stage during in 3 weeks for increased lipid accumulation) with different volumes 250 mL, 10 L, and 1,000 L. With a volume of 250 mL, the medium was supplied with benzyl adenine (BA), indole-3-acetic acid (IAA) or gibberellic acid (GA3) at concentration from 0.1 - 0.2 mg/L in initial stage and IAA or GA3 at concentration from 0.1 - 0.2 mg/L in second stage. After 10 weeks of culture, results showed that supplement of 0.1 mg/L BA in initial stage and 0.125 mg/L IAA in second stage increased cell density, and microalgal cells had green color with a spherical shape. On the contrary, supplement of 0.15 mg/L IAA in initial stage and 0.175 mg/L GA3 in second stage increased lipid accumulation, and microalgal cells had red color with a spherical shape. With a volume of 10 L, the medium was supplied with 0.1 mg/L BA in initial stage, and treated with separation or combination from 2 - 3 of these factors (nitrogen starvation, 0.5% NaCl, 4.98 mg/L FeSO4) were applied in second stage. The result showed that the cultures was treated with nitrogen starvation increased dry biomass and biofuel, but treated with 4.98 mg/L FeSO4 only increased biofuel. With a volume of 1,000 L, microalgal cells were cultured in BB liquid medium in initial stage, and treated with 4.98 mg/L FeSO4 increased fresh 78.67 mg/mL and dry biomass 2.05 mg/L and total lipid content 28.24 %/ DW

Egfr and K-ras in molecularly targeted therapy: From In Silico to In Vitro study

Molecularly targeted therapy is a new type of cancer treatment which uses monoclonalantibodies or small substances to identify and attack cancer cells, except normal cell. This has more advantages than classical treatments. EGFR (Epidermal Growth Factor Receptor) and Kras (Kirsten-ras) are considered as two well molecular-targeted agent. In present study, we performed a systematic literature review in NCBI and computed average frequencies of EGFR and K-ras mutations in some common cancers. According to data analysis, we conclude that global published mutations which belong to these genes neither exclude each other nor associate with factors of race. We successfully designed and evaluated (1) primers for detection of EGFR and K-ras mutations by PCR-sequencing; (2) primer/probe sets are used for detection of the most seven common K-ras mutations by Allele-Specific-Realtime PCR (AS-Real-time PCR) as well as Allele-Specific PCR. Due to initial experimental results, an appropriate DNA extraction procedure from FFPE (Formalin-Fixed, ParaffinEmbedded) samples and optimal Tm for each primer couple of amplified mutation, containing regions on K-ras have been drawn. Results of K-ras mutation on colorectal cancer patients obtained from Tay Ninh Province, Viet Nam was firstly detected by using PCR-sequencing methods, then, confirmed by AS-Real-Time PCR

Isolation and identification of some . Strain from traditional fermented foods

Recent publications showed that Lactic acid bacteria (LAB) are used extensively to inhibit growth of spoilage and pathogenic bacterial strains. That is being applied in food processing such as tradition fermented food or dairy, beverage and meat products. Lactic acid bacteria can produce a variety of antibacterial agents including bacteriocin, diacetyl, etc. Thus, the isolation, identification and taxonomical characterization of each new Lactobacillus sp. strain is being more and more required. However, the large number of species in the genus Lactobacillus almost have their high phenotypic and physiological similarity which easily leads to misidentification. The present study was aimed for isolation and reliable identification of Lactobacillus sp. strains from some traditional fermented foods by on the basis of phenotypic analysis and combination of PCR and sequencing of target sequences base on 16S-23S rRNA gene. Eight strains of LAB were isolated and characterized through morpholigical, physiological, biochemical and carbohydrate fermentation tests. All of them were determined as Lactobacillus sp. Moreover, the nucleotides sequences of 16S-23S rDNA of them was compared and phylogenetic analysis to those of Lactosbacillus species in GenBank and the results confirm that four strains: L1, L3, L4 and L7 belong to Lactobacillus platarum and four strains: L2, L5, L6 and L8 belong to species L. rhamnosu

DNA hypermethylation patterns of APC gene promoter in Vietnamese high-risk HPV infected patients

Cervical cancer is the leading cause of cancer death in women in Vietnam. Virtually, cervical cancers are associated with infection of HPV (Human papilloma virus). In addition, inactivation of tumor suppressor genes (TSGs), leading by aberrant hypermethylation, an epigenetic mechanism, has been observed in cervical cancer development. Screening for early detection of cervical cancer is importantly increasing from Vietnam, therefore, in current study, we analyzed the aberrant methylation status of APC (Adenomatous polyposis coli) gene, its product has an important role in cell cycle control and maintenance of genomic stability, as the pattern of potential biomarker for cervical cancer in Vietnamese population. The liquid-based Pap test samples which were identified whether HPV-infected or low-risk HPV infected or nonHPV-infected were enrolled and analyzed by MSP (Methylation specific PCR). As the results, the hypermethylation of APC was reached to 75%, 12.5% and 30% in high-risk HPV genotype infected group, in low-risk HPV genotype infected group, and non-HPV genotype infection, respectively. Especially, the characteristic of high-risk HPV infection was also associated with the hypermethylation of candidate gene (p < 0.05). Moreover, the odds ratio and relative risk were found in the high value, counting for 10.5 (95%CI, 2.3 – 47.2) and 3.37 (95%CI, 1.3 – 8.3), respectively. In conclusion, these outcomes suggested that the aberrant hypermethylation of APC gene, which accessed in non-invasive samples, led to the potential biomarker and application in early prognosis and diagnosis to cervical cancer in Vietnamese population

Identification of bacterial intestinal pathogens by a PCR-Reverse dot blot procedure

Intestinal infections which are the important public health concern worldwide, are caused by the bacterial intestinal pathogens. The aim at our study is to develop a simultaneous, rapid, sensitive and specific diagnostic assay by using a combined PCR-Reverse dot blot method for the identification of pathogen strains, including Bacillus cereus, Clostridium botulinum, Clostridium perfringen, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., Shigella spp., Vibrio cholerae, Vibrio parahaemolyticus, Yersinia enterocolitica and Brucella spp. Based on the 16S and 23S DNA regions, the two sets of universal primers and twelve specific probes were obtained for amplification and specific detection of those twelve bacterial species. The initial experimental results using bacterial cultures and 50 clinical samples confirmed the in silico hypothesis that was previously established in universal primers and probes design as well as identified with some basic conditions for PCR and Reverse Dot Blot hybridization reactions. Thus, this procedure being further tested for the other kinds of samples such as fecal samples or foods

First record of Cantharellus minor from Vietnam with identification support from a combination of nrLSU and nrSSU phylogenetic analysis

Background: A previously identified sample XC02, which was collected from a pine forest (Pinus kesiya Royle ex Gordon), in Xuan Tho Commune, Da Lat, Lam Dong Province, Vietnam, was identified as Cantharellus minor based on morphology and nrLSU phylogeny analysis. Sequence analysis of multiple genes are becoming more and more common for phylogenetic analysis of mushrooms.Method: Total DNA was isolated from sample XC02. The primer NS1, NS4 were applied to amplify the target gene the nuclear ribosomal small subunit DNA (nrSSU). For phylogenetic analysis, individual and concatenated datasets (nrSSU and nrLSU-nrSSU) were constructed. Phylogenetic tree was constructed with MEGA 6.0 with a 1000 replicate bootstrap based on the neighbor joining, maximum likelihood, maximum parsimony method.  Results: A concatenated dataset containing a total of 14 sequences from Cantharellus, Craterellus (Cantharellaceae, Canthraellales) and Hydnum (Hydnaceae, Cantharellales) were constructed. For the specimen XC02, the phylogenies based on the first, second, and third datasets (nrLSU, nrSSU, and nrLSU-nrSSU) and the morphological analysis, reported in our previous study, strongly confirmed the identity of XC02 as Cantharellus minor.Conclusion: The combination between the morphological analysis and phylogenetic analysis is confirmed as the best approach for the identification of Cantharellus and other mushroom species that we collected in the Central Highlands, Vietnam.Keywords: nrLSU; Cantharellus, Cantharellus minor; nrSSU; nrLSU; phylogeny analysis; Vietna