IRE1α is an endoplasmic reticulum (ER) transmembrane protein with cytoplasmic kinase and endoribonuclease (RNase) domains. Under ER stress, IRE1α can splice Xbp1 mRNA enabling translation of this unfo Show more
IRE1α is an endoplasmic reticulum (ER) transmembrane protein with cytoplasmic kinase and endoribonuclease (RNase) domains. Under ER stress, IRE1α can splice Xbp1 mRNA enabling translation of this unfolded protein response transcription factor or mediate sequence-specific degradation of mRNAs through regulated IRE1α-dependent decay (RIDD). Somatic mutations in IRE1α occur in many different human cancers including non-melanoma skin cancer (NMSC). To understand their role in skin cancer pathogenesis, we generated immortalized primary mouse keratinocytes with inducible expression of multiple engineered and cancer-associated mutations, including those present in NMSC. All NMSC mutations tested were activating mutations with elevated autophosphorylation and enhanced RIDD activity relative to the degree of change seen in Xbp1 splicing. Pathway analysis of RNA-Seq data and in vitro studies showed that RNase-impaired mutations enhanced cell migration due to increased levels of active RhoA and the RIDD target Angptl4. In contrast, activating mutations caused elevated Rac1 activation, enrichment of genes involved in DNA repair, increased phospho-ATR levels and improved survival in response to UVB irradiation, a crucial etiological factor for sun-exposure-induced skin cancers. Together, these results suggest divergent roles of IRE1α mutations that mediate crucial tumor-promoting events in keratinocytes. Show less
Assessing whether next-generation DNA sequencing (NGS) can be used to screen prostate cancer for multiple gene alterations in men routinely diagnosed with this disease and/or who are entered into clin Show more
Assessing whether next-generation DNA sequencing (NGS) can be used to screen prostate cancer for multiple gene alterations in men routinely diagnosed with this disease and/or who are entered into clinical trials. Previous studies are limited and have reported only low success rates. We marked areas of cancer on H&E-stained sections from formalin-fixed needle biopsies, and used these as templates to dissect cancer-rich tissue from adjacent unstained sections. DNA was prepared using a Qiagen protocol modified to maximise DNA yield. The DNA was screened simultaneously for mutations in 365 cancer-related genes using an Illumina HiSeq 2000 NGS platform. From 63 prostate cancers examined, 59(94%) of the samples yielded at least 30 ng of DNA, the minimum amount of DNA considered suitable for NGS analysis. Patients in the D'Amico high-risk group yielded an average of 1033 ng, intermediate-risk patients 401 ng, and low-risk patients 97 ng. NGS of eight samples selected from high-risk and intermediate-risk groups gave a median exon read depth of 962 and detected TMPRRS2-ERG fusions, as well as a variety of mutations including those in the SPOP, TP53, ATM, MEN1, NBPF10, NCOR2, PIK3CB and MAP2K5 (MEK5) genes. Using the methods presented here, NGS technologies can be used to screen a high proportion of patients with prostate cancer for mutations in cancer-related genes in tissue samples opening up its general use in the context of clinical trials or routine diagnosis. Show less