Diabetes is a major public issue due to its high prevalence and long-term complications (1). The molecular pathogenesis of diabetes, however, remains largely unknown. The common forms of diabetes are syndromes with heterogeneous etiologies, each of which is influenced by polygenic and multiple environmental factors. Therefore, genetic and pathophysiologic analysis of diabetes remains a major challenge. On the other hand, recent progress in the identification of genetic alterations in monogenic disorders has provided clues for understanding the molecular pathogenesis of the common forms with similar phenotypes. There are several rare monogenic forms of diabetic syndromes, both in humans and in rodent models. In humans, there is a syndrome called maturity-onset diabetes of the young (MODY), which is inherited in an autosomal dominant mode (2). The primary lesions in these diseases are in the pancreatic β cells, resulting in decreased insulin secretion. The causal genes of some types of MODY were recently identified (3).In contrast, most of the monogenic diabetic syndromes in rodent models such as ob, db, agouti, tubby, and fat mice accompany obesity (4). The responsible genes are involved in the regulation of body weight, and their alterations result in increased insulin resistance in peripheral tissues, except in fat mice. Very recently, Yoshioka and colleagues established a monogenic diabetic model, called the Akita mouse (5). This model does not accompany either obesity or insulitis, but is accompanied by a notable pancreatic β-cell dysfunction, which distinguishes this mouse from the other well-characterized animal models. Diabetes in this mouse resembles that of human MODY in terms of early onset, an autosomal dominant mode of inheritance, and primary dysfunction of the β cells. The gene locus is named murine Mody and has been determined to be located on a distal end of Chromosome 7 by linkage analysis (5) and quantitative trait locus analysis (6).In this study, we demonstrate that the Mody mouse has a missense mutation of the insulin 2 gene (Ins2), which lies on a corresponding area of the Mody locus identified by the genetic analysis. This mutation completely cosegregates with the qualitative phenotype of diabetes in the Mody congenic lines, and it is therefore concluded to be responsible for diabetes in this mouse. The Mody mutation codes insulin 2, whose cysteine residue at the seventh amino acid of the A chain is replaced with tyrosine. This cysteine is involved in the formation of one of the Received for publication June 30, 1998, and accepted in revised form November 10, 1998.The mouse autosomal dominant mutation Mody develops hyperglycemia with notable pancreatic β-cell dysfunction. This study demonstrates that one of the alleles of the gene for insulin 2 in Mody mice encodes a protein product that substitutes tyrosine for cysteine at the seventh amino acid of the A chain in its mature form. This mutation disrupts a disulfide bond between the A and B chains and can induce a drastic conformational chan...

This study has shed light on heterogeneity in lung cancers, especially in adenocarcinomas, by establishing a molecularly, genetically, and clinically relevant, expression profile-defined classification. Future studies using independent patient cohorts are warranted to confirm the prognostic significance of EGFR mutations in TRU-type adenocarcinoma.

In cancer cells the small compounds erastin and RSL3 promote a novel type of cell death called ferroptosis, which requires iron‐dependent accumulation of lipid reactive oxygen species. Here we assessed the contribution of lipid peroxidation activity of lipoxygenases (LOX) to ferroptosis in oncogenic Ras‐expressing cancer cells. Several 12/15‐LOX inhibitors prevented cell death induced by erastin and RSL3. Furthermore, siRNA‐mediated silencing of ALOX15 significantly decreased both erastin‐induced and RSL3‐induced ferroptotic cell death, whereas exogenous overexpression of ALOX15 enhanced the effect of these compounds. Immunofluorescence analyses revealed that the ALOX15 protein consistently localizes to cell membrane during the course of ferroptosis. Importantly, treatments of cells with ALOX15‐activating compounds accelerated cell death at low, but not high doses of erastin and RSL3. These observations suggest that tumor ferroptosis is promoted by LOX‐catalyzed lipid hydroperoxide generation in cellular membranes.

Amplification and overexpression of the miR-17-92 microRNAs (miRNA) cluster at 13q31.3 has recently reported, with pointers to functional involvement in the development of B-cell lymphomas and lung cancers. In the present study, we show that inhibition of miR-17-5p and miR-20a with antisense oligonucleotides (ONs) can induce apoptosis selectively in lung cancer cells overexpressing miR-17-92, suggesting the possibility of 'OncomiR addiction' to expression of these miRNAs in a subset of lung cancers. In marked contrast, antisense ONs against miR18a and miR-19a did not exhibit such inhibitory effects, whereas inhibition of miR-92-1 resulted in only modest reduction of cell growth, showing significant distinctions among miRNAs of the miR-17-92 cluster in terms of their roles in cancer cell growth. During the course of this study, we also found that enforced expression of a genomic region, termed C2, residing 3 0 to miR-17-92 in the intron 3 of C13orf25 led to marked growth inhibition in association with double stranded RNA-dependent protein kinase activation. Finally, this study also revealed that the vast majority of C13orf25 transcripts are detected as Drosha-processed cleavage products on Northern blot analysis and that a novel polyadenylation site is present 3 0 to the miR-17-92 cluster and 5 0 to the C2 region. Taken together, the present findings contribute towards better understanding of the oncogenic roles of miR-17-92, which might ultimately lead to the future translation into clinical applications.