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M Gabrovska,1 F Geurs,1 S Ponette,2 J Ponette,2 K Bulte,2 L Derveaux,3 I Kempeneers41Depts of Medical Oncology, 2Gastroenterology, 3Pneumology and 4Surgery, Regionaal Ziekenhuis Sint Maria, Halle, BelgiumAbstract: Few data are available on patient management in jaundice caused by liver metastases of solid tumors (nonbreast and noncolon origin). We report the first patient series consecutively treated with cisplatin weekly in patients with severe jaundice and liver failure due to underlying metastatic neoplasms. In 4 out of 8 cases, liver function tests were reversed and jaundice disappeared, permitting subsequent standard chemotherapy. The other 4 patients died 3 to 5 weeks after admission, illustrating the extent and severity of the underlying neoplasm.Keywords: liver failure, jaundice, metastases, chemotherapy, cisplatin

Cancer patients often receive a combination of antibodies targeting programmed death-ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen-4 (CTLA4). We conducted a window-of-opportunity study in head and neck squamous cell carcinoma (HNSCC) to examine the contribution of anti-CTLA4 to anti-PD-L1 therapy. Single-cell profiling of on- versus pre-treatment biopsies identified T cell expansion as an early response marker. In tumors, anti-PD-L1 triggered the expansion of mostly CD8 + T cells, whereas combination therapy expanded both CD4 + and CD8 + T cells. Such CD4 + T cells exhibited an activated T helper 1 (Th1) phenotype. CD4 + and CD8 + T cells co-localized with and were surrounded by dendritic cells expressing T cell homing factors or antibody-producing plasma cells. T cell receptor tracing suggests that anti-CTLA4, but not anti-PD-L1, triggers the trafficking of CD4 + naive/central-memory T cells from tumor-draining lymph nodes (tdLNs), via blood, to the tumor wherein T cells acquire a Th1 phenotype. Thus, CD4 + T cell activation and recruitment from tdLNs are hallmarks of early response to anti-PD-L1 plus anti-CTLA4 in HNSCC., Competing Interests: Declaration of interests P.M.C. reports the mentioned grant and non-financial support from AstraZeneca during the study; personal fees and non-financial support from AbbVie, Bayer, Bristol-Myers Squibb, Merck, LEO Pharma, and Vifor Pharma; personal fees from Daiichii Sankyo, and Rakuten; and non-financial support from Teva, Novartis, Amgen, and Roche outside the submitted work., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Histone deacetylases (HDACs) are enzymes pursued as drug targets in various cancers and several non-oncological conditions, such as inflammation and neurodegenerative disorders. In the past decade, HDAC inhibitors (HDACi) have emerged as relevant pharmaceuticals, with many efforts devoted to the development of new representatives. However, the growing safety concerns regarding the established hydroxamic acid-based HDAC inhibitors tend to drive current research more toward the design of inhibitors bearing alternative zinc-binding groups (ZBGs). This Perspective presents an overview of all non-hydroxamic acid ZBGs that have been incorporated into the clinically approved prototypical HDACi, suberoylanilide hydroxamic acid (vorinostat). This provides the unique opportunity to compare the inhibition potential and biological effects of different ZBGs in a direct way, as the compounds selected for this Perspective differ only in their ZBG. To that end, different strategies used to select a ZBG, its properties, activity, and liabilities are discussed.

Multiple lines of evidence have linked oxidative stress, tau pathology and neuronal cell cycle re-activation to Alzheimer's disease (AD). While a prevailing idea is that oxidative stress-induced neuronal cell cycle reactivation acts as an upstream trigger for pathological tau phosphorylation, others have identified tau as an inducer of cell cycle abnormalities in both mitotic and postmitotic conditions. In addition, nuclear hypophosphorylated tau has been identified as a key player in the DNA damage response to oxidative stress. Whether and to what extent these observations are causally linked remains unclear. Using immunofluorescence, fluorescence-activated nucleus sorting and single-nucleus sequencing, we report an oxidative stress-associated accumulation of nuclear hypophosphorylated tau in a subpopulation of cycling neurons confined in S phase in AD brains, near amyloid plaques. Tau downregulation in murine neurons revealed an essential role for tau to promote cell cycle progression to S phase and prevent apoptosis in response to oxidative stress. Our results suggest that tau holds oxidative stress-associated cycling neurons in S phase to escape cell death. Together, this study proposes a tau-dependent protective effect of neuronal cell cycle reactivation in AD brains and challenges the current view that the neuronal cell cycle is an early mediator of tau pathology., Competing Interests: Declaration of Competing Interests The authors declare that they have no competing interests., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Non-selective inhibition of different histone deacetylase enzymes by hydroxamic acid-based drugs causes severe side effects when used as a (long-term) cancer treatment. In this work, we searched for a potent zinc-binding group able to replace the contested hydroxamic acid by employing a lean inhibitor strategy. This instructed the synthesis of a set of HDAC6-selective inhibitors containing the more desirable mercaptoacetamide moiety. Biological evaluation of these new compounds showed an IC 50 in the nanomolar range, dose-dependent HDAC6 inhibition in MM1.S cells and improved genotoxicity results, rendering these new inhibitors valuable hits for applications even beyond oncology.

Our study investigates the biochemical and functional impact of selective histone deacetylase 6 (HDAC6) inhibitors, a promising class of novel therapeutics, in several cancer models. Selective HDAC6 inhibitors (Tubathian A, Tubastatin A, Tubacin and Ricolinostat) and a non-selective HDAC inhibitor (Vorinostat) were evaluated on cancer cell lines derived from multiple tumour types in both an in vitro and in vivo setting as potential cancer therapeutics. Selective HDAC6 inhibitors resulted in α-tubulin acetylation with no impact on histone acetylation but failed to show any anti-cancer properties. Only the use of high concentrations of selective HDAC6 inhibitors resulted in co-inhibition of other HDAC enzymes and consequently in reduced growth, migratory and/or invasive activity of cancer cells in vitro as well as in vivo. The specificity of HDAC6 inhibition was confirmed using a CRISPR/Cas9 knockout cell line. Our results suggest that selective HDAC6 inhibitors may fall short as potential single agent anti-cancer drugs and prove that many previous data regarding this promising class of compounds need to be interpreted with great care due to their use in high concentrations resulting in low selectivity and potential off-target effects., (© 2019 UICC.)

The diversity of cell types and regulatory states in the brain, and how these change during aging, remains largely unknown. We present a single-cell transcriptome atlas of the entire adult Drosophila melanogaster brain sampled across its lifespan. Cell clustering identified 87 initial cell clusters that are further subclustered and validated by targeted cell-sorting. Our data show high granularity and identify a wide range of cell types. Gene network analyses using SCENIC revealed regulatory heterogeneity linked to energy consumption. During aging, RNA content declines exponentially without affecting neuronal identity in old brains. This single-cell brain atlas covers nearly all cells in the normal brain and provides the tools to study cellular diversity alongside other Drosophila and mammalian single-cell datasets in our unique single-cell analysis platform: SCope (http://scope.aertslab.org). These results, together with SCope, allow comprehensive exploration of all transcriptional states of an entire aging brain., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Recent studies point towards the possible disadvantages of using hydroxamic acid-based zinc-binding groups in HDAC inhibitors due to e.g. mutagenicity issues. In this work, we elaborated on our previously developed Tubathian series, a class of highly selective thiaheterocyclic HDAC6 inhibitors, by replacing the benzohydroxamic acid function by an alternative zinc chelator, i.e. , an aromatic trifluoromethyl ketone. Unfortunately, these compounds showed a reduced potency to inhibit HDAC6 as compared to their hydroxamic acid counterparts. In agreement, the most active trifluoromethyl ketone was unable to influence the growth of SK-OV-3 ovarian cancer cells nor to alter the acetylation status of tubulin and histone H3. These data suggest that replacement of the zinc-binding hydroxamic acid function with a trifluoromethyl ketone zinc-binding moiety within reported benzohydroxamic HDAC6 inhibitors should not be considered as a standard strategy in HDAC inhibitor development.

Truncating mutations in the tumor suppressor gene adenomatous polyposis coli (APC) are the initiating step in the vast majority of sporadic colorectal cancers, and they underlie familial adenomatous polyposis (FAP) syndromes. Modeling of APC- driven tumor formation in the mouse has contributed substantially to our mechanistic understanding of the associated disease, but additional models are needed to explore therapeutic opportunities and overcome current limitations of mouse models. We report on a novel and penetrant genetic cancer model in Xenopus tropicalis, an aquatic tetrapod vertebrate with external development, diploid genome and short life cycle. Tadpoles and froglets derived from embryos injected with TAL effector nucleases targeting the apc gene rapidly developed intestinal hyperplasia and other neoplasms observed in FAP patients, including desmoid tumors and medulloblastomas. Bi-allelic apc mutations causing frame shifts were detected in the tumors, which displayed activation of the Wnt/β-catenin pathway and showed increased cellular proliferation. We further demonstrate that simultaneous double bi-allelic mutation of apc and a non-relevant gene is possible in the neoplasias, opening the door for identification and characterization of effector or modifier genes in tumors expressing truncated apc. Our results demonstrate the power of modeling human cancer in Xenopus tropicalis using mosaic TALEN-mediated bi-allelic gene disruption.