Upregulation of microRNA-126-5p is associated with drug resistance to cytarabine and poor prognosis in AML patients.

MicroRNAs (miRs) have been shown to negatively regulate gene expression by binding to mRNAs, and they play an important role in various physiological processes and malignancies. A previous study identified mature miR-126-3p as an onco-microRNA that is generated from the pre­microRNA, miR-126. Although miR-126 also generates mature miR-126-5p, its function is less clear. In the present study, the relationship between miR-126-5p/3p expression levels and overall survival in 109 patients with acute myeloid leukemia (AML) who received intensive therapy were evaluated. Higher expression levels above the median value of miR-126-5p/3p were correlated with a poorer overall survival. The hazard ratio and 95% confidence intervals (95% CI) for the higher expression group relative to the lower expression group of miR-126-5p/3p were 2.098 (95% CI: 1.075-4.228) and 1.958 (95% CI: 1.001-3.927), respectively. An interaction was not observed between the hazard ratios of miR-126-5p and miR­126-3p (p=0.73). Transfection of the mimic miR-126-5p into the AML cell line, KG-1, resulted in a decrease in the sensitivity to cytarabin and the expression level of Klotho mRNA as well as the elevation in the phosphorylation of Akt. The results of the present study demonstrated that higher expression levels of miR-126-5p/3p in patients with AML resulted in a poorer prognosis. Furthermore, miR-126-5p elevated the phosphorylation of Akt.

Japanese external quality assessment program to standardize HIV-1 drug-resistance testing (JEQS2010 program) using in vitro transcribed RNA as reference material.

To design appropriate antiretroviral therapy regimens and avoid the emergence of human immunodeficiency virus (HIV)-1 variants with reduced susceptibility to antiretroviral drugs, genotypic drug-resistance testing (HIV genotyping) is strongly recommended. To monitor the quality of HIV genotyping in Japan, we performed an external quality assessment (EQA), named the Japanese external quality assessment program, to standardize HIV genotyping (JEQS). To accurately evaluate the quality of HIV genotyping, we employed as reference material (RM) a well-characterized sample, in vitro transcribed RNA (trRNA) that includes the HIV gag-pol sequence, and created a JEQS2010 panel consisting of three single variant and three mixed trRNA samples. All 11 participating laboratories showed high concordance rates (>96%) for the single variant samples. Eight laboratories also showed good rates of detecting minor variants, but three laboratories failed to detect the variants comprising one-half of the sample. These three laboratories used a common primer that had four internal mismatches to the minor trRNA clone. This program showed the usefulness of trRNA as RM, the high quality of HIV genotyping, and extensive interlaboratory variation in the ability to detect minor variants. These results suggest that improving the quality of HIV genotyping in Japan requires regularly implementing the EQA program and improving the HIV genotyping protocol in each laboratory.

The diagnostic utility of matrix metalloproteinase-3 and high-sensitivity C-reactive protein for predicting rheumatoid arthritis in anti-cyclic citrullinated peptide antibody-negative patients with recent-onset undifferentiated arthritis.

Anti-cyclic citrullinated peptide (anti-CCP) antibodies are well-established serological markers that show high sensitivity and specificity in early rheumatoid arthritis (RA) and are associated with bone erosions of RA. However, some patients subsequently progress to RA even if there is no presence of anti-CCP antibodies in an early stage. The aim of this study is to evaluate the diagnostic utility of matrix metalloproteinase-3 (MMP-3), high-sensitivity C-reactive protein (hsCRP) and IgM rheumatoid factor for predicting RA in anti-CCP-negative patients with recent-onset undifferentiated arthritis (UA). Baseline levels of those markers were measured at the entry of the study. A total of 99 patients with UA were included, among them 44 patients (44.4 %) had been classified as having RA by a skilled rheumatologist at some point during 1-year follow-up. Of these 99 patients, 34 patients (34.3 %) had anti-CCP antibodies and 65 patients (65.7 %) had no anti-CCP antibodies. Eleven patients who were anti-CCP-negative developed RA. We compared sensitivity, specificity, positive predictive value and negative predictive value of serum markers of these anti-CCP-negative RA patients. The combined usage of MMP-3 with hsCRP is relatively superior to other markers as predictors of RA.

Mutation analysis of the SDHB and SDHD genes in pheochromocytomas and paragangliomas: identification of a novel nonsense mutation (Q168X) in the SDHB gene.

Pheochromocytoma (PCC) and paraganglioma (PGL) are tumors of the autonomic nervous system. The former is a tumor that occurs in only adrenal glands, and the latter can be found in the head and neck or in the thorax and abdomen. In PCC and PGL, genetic mutations account for approximately 30% of functional (secrete catecholamines) and nonfunctional cases. In addition to RET, VHL and NF-1, genes encoding succinate dehydrogenase complex subunit B (SDHB), subunit C (SDHC), and subunit D (SDHD) are recognized as susceptibility genes for PCC and PGL. Recently, PCC and PGL caused by genetic mutations of SDHB, SDHC and SDHD were established as hereditary pheochromocytoma paraganglioma syndrome (HPPS). Approximately 15% of all PCCs and PGLs are recognized as HPPS. Among these three susceptibility genes, SDHB and SDHD are known to be strongly related to HPPS. The aim of this study was to analyze SDHB and SDHD mutations in PCC and PGL patients. Among 18 patients, we identified a novel heterozygous nonsense mutation at codon 168 resulting in a CAG (glutamine) to TAG (stop) substitution (Q168X) in the SDHB gene in a patient diagnosed with solitary sporadic PGL. A number of studies have reported that SDHB mutation-associated disease demonstrates a higher rate of malignancy. However, all seven patients diagnosed with malignancy in this study did not have genetic mutation of SDHB and only one patient with no malignant sign had genetic mutation of SDHB. Further accumulation of cases is necessary to confirm the association between SDHB mutation and malignant potential.

Quantification of lamivudine-resistant hepatitis B virus mutants by type-specific TaqMan minor groove binder probe assay in patients with chronic hepatitis B.

BACKGROUND: Lamivudine (LAM)-resistant hepatitis B virus (HBV) with mutations in the polymerase region frequently appears after long-term use of LAM. Several methods allowing detection of mutant strains (YIDD, YVDD) have been reported, but they have no quantitative characteristics. In this study, we explored a unique approach for quantification of each mutant strain. METHODS: A method for detection and quantification of wild and mutant strains was developed using realtime polymerase chain reaction and type-specific minor groove binder (MGB) probes, and tested in patients with chronic hepatitis B before and after additive treatment with adefovir dipivoxil (ADV). RESULTS: A good correlation was confirmed in HBV DNA quantity obtained between the YMDD-specific MBG probe assay and Amplicor HBV Monitor assay results (P < 0.001), linear between 3 and 9 log copies/mL serum. Of 109 samples from patients with chronic hepatitis B tested by both these assays and conventional direct sequencing, 90 (88.2%) showed identical results. The assays successfully detected and quantified a single type of mutant in three of four patients with additive ADV treatment, and also two coexisting mutant types (YIDD and YVDD) in the remaining patient. CONCLUSIONS: Our specific and sensitive method for detection and quantification of HBV DNA with the wild-type YMDD motif and its two mutant forms (YIDD and YVDD) appears to be clinically useful, especially in patients with multiple mutant HBV infections.