Daisuke Kasai

HCV replication suppresses cellular glucose uptake through down-regulation of cell surface expression of glucose transporters☆

BACKGROUND/AIMS Persistent infection with hepatitis C virus (HCV) causes extrahepatic diseases, including diabetes. We investigated the possible effect(s) of HCV replication on cellular glucose uptake and expression of the facilitative glucose transporter (GLUT) 2 and 1. METHODS We used Huh-7.5 cells harboring either an HCV subgenomic RNA replicon (SGR) or an HCV full-genomic RNA replicon (FGR), HCV-infected cells, and the respective cells treated with interferon (IFN). We also used liver tissue samples obtained from patients with or without HCV infection. RESULTS Glucose uptake and surface expression of GLUT2 and GLUT1 were suppressed in SGR, FGR and HCV-infected cells compared to the control cells. Expression levels of GLUT2 mRNA, but not GLUT1 mRNA, were lower in SGR, FGR and HCV-infected cells than in the control. Luciferase reporter assay demonstrated decreased GLUT2 promoter activities in SGR, FGR and HCV-infected cells. IFN treatment restored glucose uptake, GLUT2 surface expression, GLUT2 mRNA expression and GLUT2 promoter activities. Also, GLUT2 expression was reduced in hepatocytes of liver tissues obtained from HCV-infected patients. CONCLUSIONS HCV replication down-regulates cell surface expression of GLUT2 partly at the transcriptional level, and possibly at the intracellular trafficking level as suggested for GLUT1, thereby lowering glucose uptake by hepatocytes.

Cellular HIV-1 DNA levels in patients receiving antiretroviral therapy strongly correlate with therapy initiation timing but not with therapy duration.

BackgroundViral reservoir size refers to cellular human immunodeficiency virus-1 (HIV-1) DNA levels in CD4+ T lymphocytes of peripheral blood obtained from patients with plasma HIV-1-RNA levels (viral load, VL) maintained below the detection limit by antiretroviral therapy (ART). We measured HIV-1 DNA levels in CD4+ lymphocytes in such patients to investigate their clinical significance.MethodsCD4+ T lymphocytes were isolated from the peripheral blood of 61 patients with a VL maintained at less than 50 copies/ml for at least 4 months by ART and total DNA was purified. HIV-1 DNA was quantified by nested PCR to calculate the copy number per 1 million CD4+ lymphocytes (relative amount) and the copy number in 1 ml of blood (absolute amount). For statistical analysis, the Spearman rank or Wilcoxon signed-rank test was used, with a significance level of 5%.ResultsCD4 cell counts at the time of sampling negatively correlated with the relative amount of HIV-1 DNA (median = 33 copies/million CD4+ lymphocytes; interquartile range [IQR] = 7-123 copies/million CD4+ lymphocytes), but were not correlated with the absolute amounts (median = 17 copies/ml; IQR = 5-67 copies/ml). Both absolute and relative amounts of HIV-1 DNA were significantly lower in six patients in whom ART was initiated before positive seroconversion than in 55 patients in whom ART was initiated in the chronic phase, as shown by Western blotting. CD4 cell counts before ART introduction were also negatively correlated with both the relative and absolute amounts of HIV-1 DNA. Only the relative amounts of HIV-1 DNA negatively correlated with the duration of VL maintenance below the detection limit, while the absolute amounts were not significantly correlated with this period.ConclusionsThe amounts of cellular HIV-1 DNA in patients with VLs maintained below the detection limit by the introduction of ART correlated with the timing of ART initiation but not with the duration of ART. In addition, CD4+ T lymphocytes, which were newly generated by ART, diluted latently infected cells, indicating that measurements of the relative amounts of cellular HIV-1 DNA might be underestimated.

Large-cell neuroendocrine carcinoma of lung with epidermal growth factor receptor (EGFR) gene mutation and co-expression of adenocarcinoma markers: a case report and review of the literature

PurposeA high rate of response to treatment with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has been observed in certain patients (women, of East Asian ethnicity, with non-smoking history and adenocarcinoma histology) with mutations in exons 18 to 21 of the tyrosine kinase domain of EGFR. Some cases of high-grade neuroendocrine carcinoma of the lung harboring mutations have been sporadically reported.MethodsWe describe the case of a 78-year-old woman with large-cell neuroendocrine carcinoma of the lung, with mutation in exon 21 L858R and co-expression of adenocarcinoma markers.ResultsA mass (3.0 cm in diameter) was identified in the inferior lobe of the left lung, accompanied by metastases into ipsilateral mediastinal lymph nodes and elevations of serum pro-gastrin-releasing peptide and carcinoembryonic antigen. Initial transbronchial brushing cytology suggested high-grade neuroendocrine carcinoma favoring small-cell carcinoma in poorly smeared and degenerated preparations, and revealed exon 21 L858R mutation. Re-enlargement of the cancer and bone metastases was observed after chemotherapy, and further testing suggested large-cell neuroendocrine carcinoma with immunoreactivity to markers of primary lung adenocarcinoma and L858R mutation. High-grade neuroendocrine carcinoma with mutations in the tyrosine kinase domain of EGFR may be associated with adenocarcinoma, as reviewed from the literature and may also apply to our case.ConclusionsEGFR-TKI could provide better quality of life and survival in patients with advanced or relapsed high-grade neuroendocrine carcinoma with EGFR gene mutations. Further studies in this respect are warranted.

Usefulness of the Oximetry Test for the Diagnosis of Sleep Apnea Syndrome in Japan

We evaluated the usefulness of oximetry tests that are frequently used as screening tools for sleep apnea syndrome (SAS) by determining the level of agreement between oximetry test results and polysomnography test (PSG) results. We retrospectively examined 135 patients suspected of having SAS. Although the oximetry desaturation index (DSI) seemed better than the oximetry apnea index in the agreement with the polysomnography respiratory disturbance index (RDI), the criteria of DSI greater than or equal to 15 was not sensitive enough to screen for moderate SAS (PSG-RDI ≥ 20). Multivariate analyses revealing that body mass index (BMI) as well as DSI correlated well with PSG-RDI, we established a new criterion by adding the BMI score (DSI ≥ 15 or BMI ≥ 25), which remarkably improved the sensitivity. This criterion may be useful not only in clinical practice but also in medical checkups for asymptomatic patients, and also suggests that obese patients with sleep disturbance should undergo PSGs, irrespective of the DSI score.

Successful Erlotinib Treatment for a Patient with Gefitinib-Related Hepatotoxicity and Lung Adenocarcinoma Refractory to Intermittently Administered Gefitinib

A 73-year-old Japanese man was histologically diagnosed with lung adenocarcinoma harboring an exon 19 deletion in the epidermal growth factor receptor. The patient was treated with gefitinib for 6 weeks until he developed substantially elevated hepatic enzyme levels that resulted in the discontinuation of gefitinib. Gefitinib was reintroduced with an intermittent treatment schedule after the transaminase levels normalized, but the patients enzyme levels rose again, and the cancer progressed. Gefitinib was eventually replaced with erlotinib. There was stable disease for 7 weeks without any signs of liver toxicity. Thus, erlotinib may be a beneficial and well-tolerated treatment option for patients with gefitinib-related hepatotoxicity.

Correlation between UGT1A1 polymorphisms and raltegravir plasma trough concentrations in Japanese HIV-1-infected patients

Raltegravir (RAL), an HIV integrase inhibitor, is metabolized mainly by UDP-glucuronosyltransferase 1A1 (UGT1A1). Polymorphisms in UGT1A1 may cause alterations in the pharmacodynamics of RAL, which is taken twice daily with no dietary restrictions. We compared the effect of two polymorphic alleles in this gene, UGT1A1*6 and UGT1A1*28 on plasma RAL concentrations in Japanese HIV-1-infected patients. Of 114 Japanese HIV-1-infected patients who received RAL, the frequencies of UGT1A1*6 and UGT1A1*28 were 18% and 13%, respectively. The percentage of homozygotes for UGT1A1*6 and UGT1A1*28 was 6% and 4%, respectively, the percentage of compound heterozygotes for UGT1A1*6 and UGT1A1*28 was 2%, and that of heterozygotes for UGT1A1*6 and UGT1A1*28 was 22% and 17%, respectively. RAL plasma trough concentrations were compared for each polymorphism. Significantly higher levels of RAL were observed with patients who were homozygous for UGT1A1*6 (median: 1.0 μg/mL) than for the normal allele (median: 0.11 μg/mL; p = 0.021). Multivariate logistic regression analysis showed that the presence of one or two alleles of UGT1A1*6 or two alleles of UGT1A1*28 were independent factors associated with high RAL plasma trough concentrations (≥ 0.17 μg/mL). These results indicated that UGT1A1*6 and UGT1A1*28 are both factors influencing the RAL plasma trough concentrations in Japanese HIV-1-infected patients.