Browsing Faculty of Medicine, Dentistry and Life Sciences by Publisher "American Association for Cancer Research"
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Changes in cervical keratinocyte gene expression associated with integration of human papillomavirus 16Episomal integration is a critical event in human papillomavirus (HPV)-related oncogenesis, although little information is currently available concerning the effect of integration on the host transcriptome. Expression microarrays were used to investigate the effect of integration of HPV16 on gene expression in cervical keratinocytes, using the unique cell line model W12. W12 was generated from a cervical low-grade squamous intraepithelial lesion "naturally" infected with HPV16 and at low passage contains approximately 100 HPV16 episomes/cell. With passage in vitro, integration of viral episomes is associated with the development of phenotypic and genomic abnormalities resembling those seen in cervical neoplastic progression in vivo. The Affymetrix U95A oligonucleotide array that contains probes for 12,600 human transcripts was used and 85 genes from a range of host cell pathways that show changes in expression levels after integration of HPV16 were identified. A range of genes not previously described as being involved in cervical neoplastic progression were identified. Interestingly, integration is associated with up-regulation of numerous IFN-responsive genes, in comparison with a baseline of episomally infected cells. These genes include p48, a component of the primary regulator of the IFN response pathway, IFN-stimulated gene factor 3. The physical state of high-risk HPV may substantially influence the response to IFN in infected keratinocytes.
Discovery of a Novel CIP2A Variant (NOCIVA) with clinical relevance in predicting TKI resistance in myeloid leukemiasPurpose: Cancerous inhibitor of PP2A (CIP2A) is an oncoprotein that inhibits the tumor suppressor PP2A-B56a. However, CIP2A mRNA variants remain uncharacterized. Here, we report the discovery of a CIP2Asplicing variant, NOCIVA (NOvel CIp2a VAriant). Experimental Design: Characterization of CIP2A variants was performed by both 3' and 5' rapid amplification of cDNA ends from cancer cells. The function of NOCIVA was assessed by structural and molecular biology approaches. Its clinical relevance was studied in an acute myeloid leukemia (AML) patient cohort and two independent chronic myeloid leukemia (CML) cohorts. Results: NOCIVA contains CIP2A exons 1-13 fused to 349 nucleotides from CIP2A intron 13. Intriguingly, the first 39 nucleotides of the NOCIVA-specific sequence are in the coding frame with exon 13 of CIP2A and code for a 13 amino acid peptide tail nonhomologous to any known human protein sequence. Therefore, NOCIVA translates to a unique human protein. NOCIVA retains the capacity to bind to B56a, but whereas CIP2A is predominantly a cytoplasmic protein, NOCIVA translocates to the nucleus. Indicative of prevalent alternative splicing from CIP2A to NOCIVA in myeloid malignancies, AML and CML patient samples overexpress NOCIVA but not CIP2A mRNA. In AML, a high NOCIVA/CIP2A mRNA expression ratio is a marker for adverse overall survival. In CML, high NOCIVA expression is associated with inferior event-free survival among imatinib-treated patients, but not among patients treated with dasatinib or nilotinib. Conclusions: We discovered novel variant of the oncoprotein CIP2A and its clinical relevance in predicting tyrosine kinase inhibitor therapy resistance in myeloid leukemias.