ABSTRACT
@#Introduction: Drug-resistance is a major hindrance to successful treatment of AML. Current predictive biomarkers are mainly genetic aberrations and insufficient in foretelling treatment outcome in all acute myeloid leukaemia (AML) due to its heterogeneous and aggressive nature. Proteins are stable and reliable. Secreted proteins in AML may have predictive or prognostic values for early intervention. Proteomic studies on AML are few and further investigations will benefit in selection of best markers. The aim of the study was to identify differentially expressed plasma proteins in AML with different treatment outcome. Methods: Two-dimensional electrophoresis (2-DE) technique was utilised to identify proteins differentially expressed in chemo-sensitive/chemo-resistant AML. Plasma and peripheral blood mononuclear cell (PBMC) lysate proteome analysis were performed on six chemo-resistant, four chemo-sensitive and six healthy controls and seven chemo-resistant, three chemo-sensitive and six healthy controls, respectively. Each experiment was conducted in duplicate or triplicate. Images were captured and protein spots detected by software. Differentially expressed protein spots were excised from gel and proteins were identified using LC/MS/MS. Proteins spots that were also detected in healthy controls were excluded. Results: Comparing mean % volume of each spot demonstrated significantly enhanced expression of apoliprotein-E (APO-E) and haptoglobin (HP) (p<0.05) in plasma and HNRNP H1 (p=0.049) in cell lysate of chemo-sensitive group. Serotransferrin (STF) from plasma and DNA-PK from cell lysate (p=0.01) were associated with chemo-resistance. Conclusion: This preliminary study identified several potential predictive biomarkers associated with chemo-resistance/chemo-sensitivity to treatment in AML. Further studies with a larger number of samples are required to validate the results.
ABSTRACT
Aims: The aim of this study was to investigate the genetic relatedness of the most prevalent Candida bloodstream infection (BSI) species in in a Malaysian population via Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) fingerprinting. Methodology and results: The genomic DNA of 43 Candida BSI blood culture samples obtained from Universiti Malaya Medical Centre (UMMC) was isolated, after which species identification was carried out using PCR with ITS-1 and ITS-4 pan-fungal primers in conjunction with CHROMagar™ Candida. The predominant Candida species in the BSI samples is Candida albicans (14 out of 43 isolates). RAPD-PCR on these 14 C. albicans clinical isolates was performed using PST as the arbitrary primer. Data analysis using MEGA found an overall non-relatedness of these 14 clinical isolates [average similarity coefficient (SAB) value 0.733±0.172]. Following in-depth analysis, five of the 14 isolates were observed to be identical (SAB values of 1.00 each), four isolates had SAB values of 0.80-0.99, indicating that they are highly similar, but are non-identical, while five isolates are unrelated (SAB lower than 0.80). This suggests that microevolution might have occurred and that these clinical isolates may possibly belong to different strains. Conclusion, significance and impact of study: A fair degree of genetic heterogeneity was found among the 14 C. albicans isolates from UMMC. To our knowledge, this is the first report on the genetic profiles of C. albicans bloodstream infection isolates from Malaysia, warranting further studies in the possible evolutionary trends within this Candida species in Malaysia. Keywords: Randomly Amplified Polymorphic DNA PCR (RAPD-PCR), Candida albicans, Candida bloodstream infections, Genetic relatedness, DNA fingerprinting
Subject(s)
Candida albicansABSTRACT
One of the main factors for virulence of fungus such as Candida albicans is the ability to change its morphology from yeast to hyphae. Allicin, one of the volatile sulfur-oil compounds from freshly crushed garlic, has a variety of antifungal activities. In this study, the effect of allicin on growth and hyphae production in C. albicans as compared to fluconazole, an antifungal drug was investigated using survival time in vitro and microscopic image at different time intervals. Additionally, the expression of selected genes involved in hyphae formation and development such as SIR2 and SAP1-4 was evaluated by semi-quantitative RTPCR and relative real time RT-PCR. Allicin was shown to down-regulate the expression of SIR2 (5.54 fold), similar to fluconazole (3.48 fold) at 2x MIC concentrations. Interestingly, allicin had no effect on SAPs1-4 expression, whereas fluconazole was able to suppress SAP4 expression. Our findings showed that allicin was effective in suppressing hyphae development of C. albicans to an extent that is sometimes equal or more than fluconazole. Moreover, allicin and fluconazole seemed to share a common anti-Candida mechanism through inhibition of SIR2 gene, while fluconazole appeared to also exert its fungistatic effect through another pathway that involved SAP4 suppression.