Alterations of several microRNA (miRNA) have been linked to cancer development and its biology. To search for unique miRNA that might play a role in the development of anaplastic thyroid carcinoma (ATC), we examined the expression of multiple miRNA and their functional effects on target genes in human thyroid carcinoma cell lines. We quantitatively evaluated the expression of multiple miRNA in 10 ATC and five papillary thyroid carcinoma (PTC) cell lines, as well as primary tumors from 11 thyroid carcinoma patients (three ATC and eight PTC), using the stem-loop-mediated reverse transcription real-time polymerase chain reaction method. We also examined the target gene specificity of unique miRNA that showed differences in expression between ATC and PTC cell lines.

Small and large non-coding RNAs (ncRNAs) contribute to the acquisition of aggressive tumor behavior in diverse human malignancies. Two types of ncRNAs, miRNA‑10b (miR-10b) and homemobox (HOX) transcript antisense RNA (HOTAIR), can suppress the translation of the HOXD10 gene, an mRNA encoding a transcriptional repressor that inhibits the expression of cell migration/invasion-associated genes. Using epithelial ovarian cancer cell lines and primary tumors, we investigated whether miR‑10b and/or HOTAIR can regulate the expression of HOXD10, and whether it permits gain of pro‑metastatic gene products, matrix metallopeptidase 14 (MMP14) and ras homolog family member C (RHOC). Overexpression of miR-10b induced a decrease in HOXD10 protein expression, and upregulated the migration and invasion abilities in ovarian cancer cell lines (P<0.05). In these cells, a significant increase of MMP14 and RHOC protein was observed. No significant upregulation of the HOXD10 protein was observed in cells with the treatment of HOTAIR-siRNA. Positive signals for HOXD10 and MMP14 proteins were observed in 47 (69%) and 25 (37%) of 68 patients with epithelial ovarian cancers. An inverse correlation between HOXD10 and MMP14 immunoreactivities was observed (P<0.05), and miR-10b expression was also inversely correlated with HOXD10 protein expression (P<0.05). These results suggested that downregulation of HOXD10 expression by miR-10b overexpression may induce an increase of pro-metastatic gene products, such as MMP14 and RHOC, and contribute to the acquisition of metastatic phenotypes in epithelial ovarian cancer cells.

The anti-arrhythmic agent amiodarone (AD) is associated with numerous adverse effects, but serious liver disease is rare. The improved safety of administration of daily low doses of AD has already been established and this regimen is used for long-term medication. Nevertheless, asymptomatic continuous liver injury by AD may increase the risk of step-wise progression of non-alcoholic fatty liver disease. We present an autopsy case of AD-induced liver cirrhosis in a patient who had been treated with a low dose of AD (200 mg/d) daily for 84 mo. The patient was a 85-year-old male with a history of ischemic heart disease. Seven years after initiation of treatment with AD, he was admitted with cardiac congestion. The total dose of AD was 528 g. Mild elevation of serum aminotransferase and hepatomegaly were present. Liver biopsy specimens revealed cirrhosis, and under electron microscopy numerous lysosomes with electron-dense, whorled, lamellar inclusions characteristic of a secondary phospholipidosis were observed. Initially, withdrawal of AD led to a slight improvement of serum aminotransferase levels, but unfortunately his general condition deteriorated and he died from complications of pneumonia and renal failure. Long-term administration of daily low doses of AD carries the risk of progression to irreversible liver injury. Therefore, periodic examination of liver function and/or liver biopsy is required for the management of patients receiving long-term treatment with AD.

No abstract

Bortezomib is a potent proteasome inhibitor that has been extensively used to treat multiple myeloma. One of the most common grade 3 adverse events is cyclic thrombocytopenia. In this study, we studied the mechanism by which bortezomib induces thrombocytopenia in a mouse model. After the intravenous administration of bortezomib (2.5 mg/kg) via tail vein, platelet counts significantly decreased on days 2-4 and recovered to the normal range on day 6. Bortezomib (2.5 mg/kg) injected into mice in vivo did not affect colony-forming unit-megakaryocytes (CFU-Mk) or megakaryocytes in the bone marrow. However, proplatelet formation (PPF) significantly decreased on days 2 and 4, after bortezomib administration to mice. Meanwhile, CFU-Mk formation and the ploidy distribution of cultured megakaryocytes in vitro were not affected by bortezomib used at concentrations of ≤ 1 ng/mL. The PPF of megakaryocytes in vitro significantly decreased with 0.1, 1, 10, and 100 ng/mL bortezomib. Considering the bortezomib concentration in clinical studies, these data strongly suggest that decreased PPF activity induces thrombocytopenia. To elucidate the mechanism behind decreased PPF, Western blot was performed. Activated Rho expression increased after the incubation of murine platelets with bortezomib. Decreased PPF activity was eliminated by the addition of Y27632, a Rho kinase inhibitor, in vitro. Given that the Rho/Rho kinase pathway is a negative regulator of PPF, bortezomib increases activated Rho, inducing decreased PPF, which results in decreased platelet count.