Recent studies have revealed a role for macrophages and neutrophils in limiting chemotherapy efficacy; however, the mechanisms underlying the therapeutic benefit of myeloid-targeting agents in ...combination with chemotherapy are incompletely understood. Here, we show that targeting tumour-associated macrophages by colony-stimulating factor-1 receptor (CSF-1R) blockade in the K14cre;Cdh1
;Trp53
transgenic mouse model for breast cancer stimulates intratumoural type I interferon (IFN) signalling, which enhances the anticancer efficacy of platinum-based chemotherapeutics. Notably, anti-CSF-1R treatment also increased intratumoural expression of type I IFN-stimulated genes in patients with cancer, confirming that CSF-1R blockade is a powerful strategy to trigger an intratumoural type I IFN response. By inducing an inflamed, type I IFN-enriched tumour microenvironment and by further targeting immunosuppressive neutrophils during cisplatin therapy, antitumour immunity was activated in this poorly immunogenic breast cancer mouse model. These data illustrate the importance of breaching multiple layers of immunosuppression during cytotoxic therapy to successfully engage antitumour immunity in breast cancer.
Abstract
Oxidative allylic C–H functionalization is a powerful tool to streamline organic synthesis as it minimizes the need for functional group activation and generates alkenyl-substituted products ...amenable to further chemical modifications. The intramolecular variants can be used to construct functionalized ring structures but remain limited in scope and by their frequent requirement for noble metal catalysts and stoichiometric chemical oxidants. Here we report an oxidant-free, electrocatalytic approach to achieve intramolecular oxidative allylic C–H amination and alkylation by employing tailored cobalt-salen complexes as catalysts. These reactions proceed through a radical mechanism and display broad tolerance of functional groups and alkene substitution patterns, allowing efficient coupling of di-, tri- and even tetrasubstituted alkenes with N- and C-nucleophiles to furnish high-value heterocyclic and carbocyclic structures.
After an infection, pathogen-specific tissue-resident memory T cells (TRM cells) persist in nonlymphoid tissues to provide rapid control upon reinfection, and vaccination strategies that create TRM ...cell pools at sites of pathogen entry are therefore attractive. However, it is not well understood how TRM cells provide such pathogen protection. Here, we demonstrate that activated TRM cells in mouse skin profoundly alter the local tissue environment by inducing a number of broadly active antiviral and antibacterial genes. This “pathogen alert” allows skin TRM cells to protect against an antigenically unrelated virus. These data describe a mechanism by which tissue-resident memory CD8⁺ T cells protect previously infected sites that is rapid, amplifies the activation of a small number of cells into an organ-wide response, and has the capacity to control escape variants.
The KRAS oncoprotein, a critical driver in 33% of lung adenocarcinoma (LUAD), has remained an elusive clinical target due to its perceived undruggable nature. The identification of dependencies borne ...through common co-occurring mutations are sought to more effectively target KRAS-mutant lung cancer. Approximately 20% of KRAS-mutant LUAD carry loss-of-function mutations in KEAP1, a negative regulator of the antioxidant response transcription factor NFE2L2/NRF2. We demonstrate that Keap1-deficient Kras
lung tumors arise from a bronchiolar cell-of-origin, lacking pro-tumorigenic macrophages observed in tumors originating from alveolar cells. Keap1 loss activates the pentose phosphate pathway, inhibition of which, using 6-AN, abrogated tumor growth. These studies highlight alternative therapeutic approaches to specifically target this unique subset of KRAS-mutant LUAD cancers.
Much controversy surrounds the cell-of-origin of mutant K-Ras (K-RasG12D)–induced lung adenocarcinoma. To shed light on this issue, we have used technology that enables us to conditionally target ...K-RasG12D expression in Surfactant Protein C (SPC) ⁺ alveolar type 2 cells and in Clara cell antigen 10 (CC10) ⁺ Clara cells by use of cell-type–restricted recombinant Adeno-Cre viruses. Experiments were performed both in the presence and absence of the tumor suppressor gene p53, enabling us to assess what effect the cell-of-origin and the introduced genetic lesions have on the phenotypic characteristics of the resulting adenocarcinomas. We conclude that both SPC-expressing alveolar type 2 cells and CC10-expressing Clara cells have the ability to initiate malignant transformation following the introduction of these genetic alterations. The lungs of K-Ras ˡᵒˣ–Sᵗᵒᵖ–ˡᵒˣ–ᴳ¹²ᴰ/⁺ and K-Ras ˡᵒˣ–Sᵗᵒᵖ–ˡᵒˣ–ᴳ¹²ᴰ/⁺;tumor suppressor gene Trp53 F/F mice infected with Adeno5–SPC–Cre and Adeno5–CC10–Cre viruses displayed differences in their tumor spectrum, indicating distinct cellular routes of tumor initiation. Moreover, using a multicolor Cre reporter line, we demonstrate that the resulting tumors arise from a clonal expansion of switched cells. Taken together, these results indicate that there are multiple cellular paths to K-RasG12D–induced adenocarcinoma and that the initiating cell influences the histopathological phenotype of the tumors that arise.
Lung squamous cell carcinoma (LSCC) is a devastating malignancy with no effective treatments, due to its complex genomic profile. Therefore, preclinical models mimicking its salient features are ...urgently needed. Here we describe mouse models bearing various combinations of genetic lesions predominantly found in human LSCC. We show that SOX2 but not FGFR1 overexpression in tracheobronchial basal cells combined with Cdkn2ab and Pten loss results in LSCC closely resembling the human counterpart. Interestingly, Sox2;Pten;Cdkn2ab mice develop LSCC with a more peripheral location when Club or Alveolar type 2 (AT2) cells are targeted. Our model highlights the essential role of SOX2 in commanding the squamous cell fate from different cells of origin and represents an invaluable tool for developing better intervention strategies.
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•Pten;Cdkn2ab loss causes a diversity of tumors in tracheobronchial basal cells•SOX2 overexpression is crucial in promoting LSCC upon loss of Pten;Cdkn2ab•Sox2;Pten;Cdkn2ab mice develop LSCC from Basal, Alveolar type 2, and Club cells•Mouse LSCC phenotypically and molecularly resembles the human counterpart
Ferone et al. establish mouse models bearing various combinations of genetic alterations commonly found in human lung squamous cell carcinoma and show that SOX2, but not FGFR1, overexpression induces the squamous cell fate from different cells of origin carrying the same combined Cdkn2ab and Pten loss.
The detyrosination-tyrosination cycle involves the removal and religation of the C-terminal tyrosine of α-tubulin and is implicated in cognitive, cardiac, and mitotic defects. The vasohibin-small ...vasohibin-binding protein (SVBP) complex underlies much, but not all, detyrosination. We used haploid genetic screens to identify an unannotated protein, microtubule associated tyrosine carboxypeptidase (MATCAP), as a remaining detyrosinating enzyme. X-ray crystallography and cryo-electron microscopy structures established MATCAP's cleaving mechanism, substrate specificity, and microtubule recognition. Paradoxically, whereas abrogation of tyrosine religation is lethal in mice, codeletion of MATCAP and SVBP is not. Although viable, defective detyrosination caused microcephaly, associated with proliferative defects during neurogenesis, and abnormal behavior. Thus, MATCAP is a missing component of the detyrosination-tyrosination cycle, revealing the importance of this modification in brain formation.
Mouse xenografts from (patient-derived) tumors (PDX) or tumor cell lines are widely used as models to study various biological and preclinical aspects of cancer. However, analyses of their RNA and ...DNA profiles are challenging, because they comprise reads not only from the grafted human cancer but also from the murine host. The reads of murine origin result in false positives in mutation analysis of DNA samples and obscure gene expression levels when sequencing RNA. However, currently available algorithms are limited and improvements in accuracy and ease of use are necessary.
We developed the R-package XenofilteR, which separates mouse from human sequence reads based on the edit-distance between a sequence read and reference genome. To assess the accuracy of XenofilteR, we generated sequence data by in silico mixing of mouse and human DNA sequence data. These analyses revealed that XenofilteR removes > 99.9% of sequence reads of mouse origin while retaining human sequences. This allowed for mutation analysis of xenograft samples with accurate variant allele frequencies, and retrieved all non-synonymous somatic tumor mutations.
XenofilteR accurately dissects RNA and DNA sequences from mouse and human origin, thereby outperforming currently available tools. XenofilteR is open source and available at https://github.com/PeeperLab/XenofilteR .
Differentiation of naïve peripheral B cells into terminally differentiated plasma cells is characterized by epigenetic alterations, yet the epigenetic mechanisms that control B‐cell fate remain ...unclear. Here, we identified a role for the histone H3K79 methyltransferase DOT1L in controlling B‐cell differentiation. Mouse B cells lacking Dot1L failed to establish germinal centers (GC) and normal humoral immune responses in vivo. In vitro, activated B cells in which Dot1L was deleted showed aberrant differentiation and prematurely acquired plasma cell characteristics. Similar results were obtained when DOT1L was chemically inhibited in mature B cells in vitro. Mechanistically, combined epigenomics and transcriptomics analysis revealed that DOT1L promotes expression of a pro‐proliferative, pro‐GC program. In addition, DOT1L indirectly supports the repression of an anti‐proliferative plasma cell differentiation program by maintaining the repression of Polycomb Repressor Complex 2 (PRC2) targets. Our findings show that DOT1L is a key modulator of the core transcriptional and epigenetic landscape in B cells, establishing an epigenetic barrier that warrants B‐cell naivety and GC B‐cell differentiation.
SYNOPSIS
The histone H3K79 methyltransferase DOT1L plays a central role in B cell development and differentiation. DOT1L maintains B cells naivety by orchestrating critical transcriptional and epigenetic regulators.
DOT1L is essential for the formation of germinal center B cells.
DOT1L prevents premature differentiation of naïve B cells towards plasma cells.
DOT1L contributes to the repression of PRC2 target genes.
The histone H3K79 methyltransferase DOT1L plays a central role in B cell development and differentiation. DOT1L maintains B cells naivety by orchestrating critical transcriptional and epigenetic regulators.
L‐asparaginase (ASNase) serves as an effective drug for adolescent acute lymphoblastic leukemia. However, many clinical trials indicated severe ASNase toxicity in patients with solid tumors, with ...resistant mechanisms not well understood. Here, we took a functional genetic approach and identified SLC1A3 as a novel contributor to ASNase resistance in cancer cells. In combination with ASNase, SLC1A3 inhibition caused cell cycle arrest or apoptosis, and myriads of metabolic vulnerabilities in tricarboxylic acid (TCA) cycle, urea cycle, nucleotides biosynthesis, energy production, redox homeostasis, and lipid biosynthesis. SLC1A3 is an aspartate and glutamate transporter, mainly expressed in brain tissues, but high expression levels were also observed in some tumor types. Here, we demonstrate that ASNase stimulates aspartate and glutamate consumptions, and their refilling through SLC1A3 promotes cancer cell proliferation. Lastly, in vivo experiments indicated that SLC1A3 expression promoted tumor development and metastasis while negating the suppressive effects of ASNase by fueling aspartate, glutamate, and glutamine metabolisms despite of asparagine shortage. Altogether, our findings identify a novel role for SLC1A3 in ASNase resistance and suggest that restrictive aspartate and glutamate uptake might improve ASNase efficacy with solid tumors.
Synopsis
While L‐asparaginase is an effective drug for the treatment of childhood leukemia, toxicity and tolerance hamper its further usage in patients with solid tumors. Here, a genome‐wide functional screen identifies a role for amino acid transporter SLC1A3 in asparaginase resistance in cancer cells, suggesting a therapeutic perspective for restrictive aspartate and glutamate uptake in solid tumors.
Loss‐of‐function screen identifies SLC1A3 as facilitator of asparaginase resistance.
SLC1A3 is highly expressed in solid tumors.
Combined SLC1A3 blockade and asparaginase treatment impair cell growth in vitro and tumorigenesis in vivo.
Supplementation of intracellular aspartate and glutamate levels by SLC1A3 promotes cancerogenesis.
Amino acid transporter SLC1A3 facilitates cancer development by circumventing amino acid deprivation induced by asparaginase treatment.
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