Receptor ligand-triggered resistance to alectinib and its circumvention by Hsp90 inhibition in EML4-ALK lung cancer cells

Alectinib is a new generation ALK inhibitor with activity against the gatekeeper L1196M mutation that showed remarkable activity in a phase I/II study with echinoderm microtubule associated protein-like 4 (EML4) - anaplastic lymphoma kinase (ALK) non-small cell lung cancer (NSCLC) patients. However, alectinib resistance may eventually develop. Here, we found that EGFR ligands and HGF, a ligand of the MET receptor, activate EGFR and MET, respectively, as alternative pathways, and thereby induce resistance to alectinib. Additionally, the heat shock protein 90 (Hsp90) inhibitor suppressed protein expression of ALK, MET, EGFR, and AKT, and thereby induced apoptosis in EML4-ALK NSCLC cells, even in the presence of EGFR ligands or HGF. These results suggest that Hsp90 inhibitors may overcome ligand-triggered resistance to new generation ALK inhibitors and may result in more successful treatment of NSCLC patients with EML4-ALK.     

Purification and Characterization of Tumor Invasion-inhibiting Factors

Tumor invasion-inhibiting factors were purified from bovine liver using an in vitro system for estimating the tumor invasion ability. The acid-ethanol extract of liver was subjected to ultrafiltration (Amicon PM10 membrane), and the fraction corresponding to the molecular weight range below 10,000 was further fractionated by ion-exchange (DEAE-Toyopearl), gel filtration (Bio-Gel P6), and reverse-phase (C18) chromatographies. Two types of active polypeptides with molecular weights of about 5,000 and 2,000 were purified and named IIF-1 and IIF-2, respectively. Both peptides inhibited tumor invasion with half-maximum concentrations of 2–6 ng/ml in vitro . The amino acid compositions of both peptides were determined.     

Successful treatment of refractory gastric antral vascular ectasia using transcatheter arterial embolization

In January 2008, a 67-year-old woman was admitted to our hospital because of hepatitis C virus-related cirrhosis and hepatocellular carcinoma (HCC). In February 2010, she had tarry stools and anemia resulting from gastric antral vascular ectasia (GAVE). Argon plasma coagulation (APC) treatment for GAVE was performed at that time. She revisited our hospital in July 2010 because of tarry stools and anemia caused by GAVE recurrence, which required 5 APC sessions and blood transfusion to control the bleeding. In October 2010, she arrived at our hospital by ambulance because of hemorrhagic shock resulting from GAVE recurrence. Despite performing 5 APC sessions and multiple blood transfusions, the tarry stools and anemia persisted during the hospitalization period. In December 2010 and January 2011, second-stage selective transcatheter arterial embolization (TAE) of the right gastric and right gastroepiploic arteries using microcoils was performed for the treatment of the refractory GAVE. Upper gastrointestinal endoscopy performed after TAE revealed the disappearance of mucosal diffuse spotty redness. In addition, no complications such as gastric ulcer and necrosis were observed. Selective TAE, effectively resolved the GAVE and anemia, and no recurrence has been observed during the last 24 months. Therefore, TAE may be a safe and radical treatment for refractory GAVE.     

PATHOLOGICAL STUDY ON AMYLOIDOSIS —RELATIONSHIP OF AMYLOID DEPOSITS IN THE AORTA TO AGING—

Senile aortic amyloidosis in 224 autopsy cases over 40 years was investigated comparing cardiac and pancreatic amyloidosis in them. A total of 176 cases of aortic amyloidosis was found for an average incidence of 79%. Under the 5th decade the incidence was 51% and it rose sharply with age and reached 95% in over the 8th decade. The incidence of cardiac amyloidosis also increased with age, but it was always higher in the aorta. Aortic and cardiac amyloid were both positive in the DMAB method for tryptophan. The major part exposed to amyloidosis in the aorta was the media. The medial amyloid consisted of numerous minute deposits and had no relation to atherosclerosis. Some comments about the pathogenesis of senile amyloidosis were also mentioned.     

A rare male patient with classic Rett syndrome caused by MeCP2_e1 mutation

Rett syndrome (RTT) is a severe neurodevelopmental disorder typically affecting females. It is mainly caused by loss‐of‐function mutations that affect the coding sequence of exon 3 or 4 of methyl‐CpG‐binding protein 2 (MECP2). Severe neonatal encephalopathy resulting in death before the age of 2 years is the most common phenotype observed in males affected by a pathogenic MECP2 variant. Mutations in MECP2 exon 1 affecting the MeCP2_e1 isoform are relatively rare causes of RTT in females, and only one case of a male patient with MECP2‐related severe neonatal encephalopathy caused by a mutation in MECP2 exon 1 has been reported. This is the first reported case of a male with classic RTT caused by a 5‐bp duplication in the open‐reading frame of MECP2 exon 1 (NM_001110792.1:c.23_27dup) that introduced a premature stop codon [p.(Ser10Argfs*36)] in the MeCP2_e1 isoform, which has been reported in one female patient with classic RTT. Therefore, both males and females displaying at least some type of MeCP2_e1 mutation may exhibit the classic RTT phenotype.

     

Development of a time-resolved fluoroimmunoassay for insulins and its application to monitoring of insulin secretion induced by feeding in the barfin flounder, Verasper moseri

A time-resolved fluoroimmunoassay (TR-FIA) system was developed to quantify insulin levels in the barfin flounder. This TR-FIA system is a solid-phase assay based on competition of unlabeled insulins and biotinylated barfin flounder insulin-II against an anti-barfin flounder insulin-II antibody. The minimum detectable level of barfin flounder insulin-I and -II in this TR-FIA was 10 pg/well which corresponded to 1.0 ng/ml, and insulin-II showed slightly higher crossreactivity than insulin-I. The accuracy of this TR-FIA was assured by specificity test, validation test, and recovery test using plasma added insulin-II. The results indicated the high specificity and sufficient accuracy of this assay system for insulin level measurement. This system was applied to the measurement of plasma insulin levels of fed and fasted barfin flounders. Plasma insulin levels (average +/- SEM) in fed flounders reached a maximum 2 h (9.3 +/- 1.7 ng/ml) and decreased gradually thereafter, while those in fasted flounders remained at low levels (1.1 +/- 0.1-2.0 +/- 0.2 ng/ml) during the experiment. After removing proteins by acidification and subsequent gel filtration, plasma samples taken from fed and fasted flounders at 2 h after feeding were fractionated separately by reversed-phase HPLC. In fed flounders, insulin immunoreactivity was detected in fractions corresponding to those of insulin-I or -II. The ratio of integrated insulin immunoreactivities of each peak was 0.378 +/- 0.044 (average +/- SD). This value was in good agreement with those (0.355 +/- 0.019) of absorbance areas of each insulin from Brockmann body extracts of the barfin flounder on reversed-phase HPLC. In fasted flounders, very weak insulin immunoreactivities were observed at retention times corresponding to those of insulin-I and -II. These results indicated that both insulin-I and -II were secreted into the blood being induced by feeding stimulation with approximately the same ratio as that of the quantities harbored in the Brockmann body.