TNFa and IL2 Encoding Oncolytic Adenovirus Activates Pathogen and Danger-Associated Immunological Signaling

In order to break tumor resistance towards traditional treatments, we investigate the response of tumor and immune cells to a novel, cytokine-armed oncolytic adenovirus: Ad5/3-d24-E2F-hTNFa-IRES-hIL2 (also known as TILT-123 and OAd.TNFa-IL2). There are several pattern recognition receptors (PRR) that might mediate adenovirus-infection recognition. However, the role and specific effects of each PRR on the tumor microenvironment and treatment outcome remain unclear. Hence, the aim of this study was to investigate the effects of OAd.TNFa-IL2 infection on PRR-mediated danger- and pathogen-associated molecular pattern (DAMP and PAMP, respectively) signaling. In addition, we wanted to see which PRRs mediate an antitumor response and are therefore relevant for optimizing this virotherapy. We determined that OAd.TNFa-IL2 induced DAMP and PAMP release and consequent tumor microenvironment modulation. We show that the AIM2 inflammasome is activated during OAd.TNFa-IL2 virotherapy, thus creating an immunostimulatory antitumor microenvironment.Peer reviewe

CRISPR screens in sister chromatid cohesion defective cells reveal PAXIP1-PAGR1 as regulator of chromatin association of cohesin

The cohesin complex regulates higher order chromosome architecture through maintaining sister chromatid cohesion and folding chromatin by DNA loop extrusion. Impaired cohesin function underlies a heterogeneous group of genetic syndromes and is associated with cancer. Here, we mapped the genetic dependencies of human cell lines defective of cohesion regulators DDX11 and ESCO2. The obtained synthetic lethality networks are strongly enriched for genes involved in DNA replication and mitosis and support the existence of parallel sister chromatid cohesion establishment pathways. Among the hits, we identify the chromatin binding, BRCT-domain containing protein PAXIP1 as a novel cohesin regulator. Depletion of PAXIP1 severely aggravates cohesion defects in ESCO2 mutant cells, leading to mitotic cell death. PAXIP1 promotes global chromatin association of cohesin, independent of DNA replication, a function that cannot be explained by indirect effects of PAXIP1 on transcription or DNA repair. Cohesin regulation by PAXIP1 requires its binding partner PAGR1 and a conserved FDF motif in PAGR1. PAXIP1 co-localizes with cohesin on multiple genomic loci, including active gene promoters and enhancers. Possibly, this newly identified role of PAXIP1-PAGR1 in regulating cohesin occupancy on chromatin is also relevant for previously described functions of PAXIP1 in transcription, immune cell maturation and DNA repair.</p

Electric Field Mediated Ion Transport Through Charged Mesoporous Membranes

The transport of ions from aqueous solutions through a stacked Au/alpha-alumina/gamma-alumina/Au membrane under the influence of a dc potential difference is reported. The membrane shows high cation permselectivity at ionic strengths of ~1 mM at pH 4.3-6.5, which is associated with a combination of anion adsorption and double-layer overlap inside the pores of the gamma-alumina layer. The cation flux can be controlled by ionic strength, dc potential difference and pH

MMS22L-TONSL functions in sister chromatid cohesion in a pathway parallel to DSCC1-RFC

The leading strand-oriented alternative PCNA clamp loader DSCC1-RFC functions in DNA replication, repair, and sister chromatid cohesion (SCC), but how it facilitates these processes is incompletely understood. Here, we confirm that loss of human DSCC1 results in reduced fork speed, increased DNA damage, and defective SCC. Genome-wide CRISPR screens in DSCC1-KO cells reveal multiple synthetically lethal interactions, enriched for DNA replication and cell cycle regulation. We show that DSCC1-KO cells require POLE3 for survival. Co-depletion of DSCC1 and POLE3, which both interact with the catalytic polymerase ε subunit, additively impair DNA replication, suggesting that these factors contribute to leading-strand DNA replication in parallel ways. An additional hit is MMS22L, which in humans forms a heterodimer with TONSL. Synthetic lethality of DSCC1 and MMS22L-TONSL likely results from detrimental SCC loss. We show that MMS22L-TONSL, like DDX11, functions in a SCC establishment pathway parallel to DSCC1-RFC. Because both DSCC1-RFC and MMS22L facilitate ESCO2 recruitment to replication forks, we suggest that distinct ESCO2 recruitment pathways promote SCC establishment following either cohesin conversion or de novo cohesin loading

Discovery of a potent protein kinase D inhibitor: insights in the binding mode of pyrazolo[3,4-d] pyrimidine analogues

In this study, we set out to rationally optimize PKD inhibitors based on the pyrazolo[3,4-d]pyrimidine scaffold. The lead compound for this study was 1-NM-PP1, which was previously found by us and others to inhibit PKD. In our screening we identified one compound (3-IN-PP1) displaying a 10-fold increase in potency over 1-NM-PP1, opening new possibilities for specific protein kinase inhibitors for kinases that show sensitivity towards pyrazolo[3,4-d]pyrimidine derived compounds. Interestingly the observed SAR was not in complete agreement with the commonly observed binding mode where the pyrazolo[3,4-d]pyrimidine compounds are bound in a similar fashion as PKD's natural ligand ATP. Therefore we suggest an alternate binding mode where the compounds are flipped 180 degrees. This possible alternate binding mode for pyrazolo[3,4-d]pyrimidine based compounds could pave the way for a new class of specific protein kinase inhibitors for kinases sensitive towards pyrazolo[3,4-d]pyrmidines.crosscheck: This document is CrossCheck deposited related_data: Supplementary Information identifier: Klaas Verschueren (ORCID) identifier: Joachim Demaerel (ORCID) identifier: Arnout R. D. Voet (ResearcherID) identifier: Wim M. De Borggraeve (ORCID) identifier: Wim M. De Borggraeve (ResearcherID) copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal copyright_licence: This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0) history: Received 2 December 2016; Accepted 31 January 2017; Accepted Manuscript published 9 February 2017; Advance Article published 15 February 2017; Version of Record published 23 March 2017status: publishe

Sensitizing Triple-Negative Breast Cancer to PI3K Inhibition by Cotargeting IGF1R

Targeted therapies have proven invaluable in the treatment of breast cancer, as exemplified by tamoxifen treatment for hormone receptor-positive tumors and trastuzumab treatment for HER2-positive tumors. In contrast, a subset of breast cancer negative for these markers, triple-negative breast cancer (TNBC), has met limited success with pathway-targeted therapies. A large fraction of TNBCs depend on the PI3K pathway for proliferation and survival, but inhibition of PI3K alone generally has limited clinical benefit. We performed an RNAi-based genetic screen in a human TNBC cell line to identify kinases whose knockdown synergizes with the PI3K inhibitor GDC-0941 (pictilisib). We discovered that knockdown of insulin-like growth factor-1 receptor (IGF1R) expression potently increased sensitivity of these cells to GDC-0941. Pharmacologic inhibition of IGF1R using OSI-906 (linsitinib) showed a strong synergy with PI3K inhibition. Furthermore, we found that the combination of GDC-0941 and OSI-906 is synergistic in 8 lines from a panel of 18 TNBC cell lines. In these cell lines, inhibition of IGF1R further decreases the activity of downstream PI3K pathway components when PI3K is inhibited. Expression analysis of the panel of TNBC cell lines indicates that the expression levels of IGF2BP3 can be used as a potential predictor for sensitivity to the PI3K/IGF1R inhibitor combination. Our data show that combination therapy consisting of PI3K and IGF1R inhibitors could be beneficial in a subset of TNBCs. Mol Cancer Ther; 15(7); 1545-56. ©2016 AACR

Electric Field Mediated Ion Transport Through Charged Mesoporous Membranes

The transport of ions from aqueous solutions through a stacked Au/alpha-alumina/gamma-alumina/Au membrane under the influence of a dc potential difference is reported. The membrane shows high cation permselectivity at ionic strengths of ~1 mM at pH 4.3-6.5, which is associated with a combination of anion adsorption and double-layer overlap inside the pores of the gamma-alumina layer. The cation flux can be controlled by ionic strength, dc potential difference and pH

BIRC2–BIRC3 amplification: a potentially druggable feature of a subset of head and neck cancers in patients with Fanconi anemia

Head-and-neck squamous cell carcinomas (HNSCCs) are relatively common in patients with Fanconi anemia (FA), a hereditary chromosomal instability disorder. Standard chemo-radiation therapy is not tolerated in FA due to an overall somatic hypersensitivity to such treatment. The question is how to find a suitable alternative treatment. We used whole-exome and whole genome mRNA sequencing to identify major genomic and transcriptomic events associated with FA-HNSCC. CRISPR-engineered FA-knockout models were used to validate a number of top hits that were likely to be druggable. We identified deletion of 18q21.2 and amplification of 11q22.2 as prevailing copy-number alterations in FA HNSCCs, the latter of which was associated with strong overexpression of the cancer-related genes YAP1, BIRC2, BIRC3 (at 11q22.1-2). We then found the drug AZD5582, a known small molecule inhibitor of BIRC2-3, to selectively kill FA tumor cells that overexpressed BIRC2-3. This occurred at drug concentrations that did not affect the viability of untransformed FA cells. Our data indicate that 11q22.2 amplifications are relatively common oncogenic events in FA-HNSCCs, as holds for non FA-HNSCC. Therefore, chemotherapeutic inhibition of overexpressed BIRC2-3 may provide the basis for an approach to develop a clinically realistic treatment of FA-HNSCCs that carry 11q22.2 amplifications

ELOF1 is a transcription-coupled DNA repair factor that directs RNA polymerase II ubiquitylation

Cells employ transcription-coupled repair (TCR) to eliminate transcription-blocking DNA lesions. DNA damage-induced binding of the TCR-specific repair factor CSB to RNA polymerase II (RNAPII) triggers RNAPII ubiquitylation of a single lysine (K1268) by the CRL4CSA ubiquitin ligase. How CRL4CSA is specifically directed towards K1268 is unknown. Here, we identify ELOF1 as the missing link that facilitates RNAPII ubiquitylation, a key signal for the assembly of downstream repair factors. This function requires its constitutive interaction with RNAPII close to K1268, revealing ELOF1 as a specificity factor that binds and positions CRL4CSA for optimal RNAPII ubiquitylation. Drug–genetic interaction screening also revealed a CSB-independent pathway in which ELOF1 prevents R-loops in active genes and protects cells against DNA replication stress. Our study offers key insights into the molecular mechanisms of TCR and provides a genetic framework of the interplay between transcriptional stress responses and DNA replication