MARK2/MARK3 kinases are catalytic co-dependencies of YAP/TAZ in human cancer.

The Hippo signaling pathway is commonly dysregulated in human cancer, which leads to a powerful tumor dependency on the YAP/TAZ transcriptional coactivators. Here, we used paralog co-targeting CRISPR screens to identify the kinases MARK2/3 as absolute catalytic requirements for YAP/TAZ function in diverse carcinoma and sarcoma contexts. Underlying this observation is direct MARK2/3-dependent phosphorylation of NF2 and YAP/TAZ, which effectively reverses the tumor suppressive activity of the Hippo module kinases LATS1/2. To simulate targeting of MARK2/3, we adapted the CagA protein from H. pylori as a catalytic inhibitor of MARK2/3, which we show can regress established tumors in vivo. Together, these findings reveal MARK2/3 as powerful co-dependencies of YAP/TAZ in human cancer; targets that may allow for pharmacology that restores Hippo pathway-mediated tumor suppression.

Scribble Deficiency Promotes Pancreatic Ductal Adenocarcinoma Development and Metastasis.

Perturbation of cell polarity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) progression. Scribble (SCRIB) is a well characterized polarity regulator that has diverse roles in the pathogenesis of human neoplasms. To investigate the impact of SCRIB deficiency on PDAC development and progression, Scrib was genetically ablated in well-established mouse models of PDAC. Scrib loss in combination with KrasG12D did not influence development of pancreatic intraepithelial neoplasms (PanIN) in mice. However, Scrib deletion cooperated with KrasG12D and concomitant Trp53 heterozygous deletion to promote invasive PDAC and metastatic dissemination, leading to reduced overall survival. Immunohistochemical and transcriptome analyses revealed that Scrib-null tumors display a pronounced reduction of collagen content and cancer associated fibroblast (CAF) abundance. Mechanistically, interleukin 1α (IL1α) levels were reduced in Scrib deficient tumors, and Scrib knockdown downregulated IL1α in mouse PDAC organoids (mPDOs), which impaired CAF activation. Furthermore, Scrib loss increased YAP activation in mPDOs and established PDAC cell lines, enhancing cell survival. Clinically, SCRIB expression was decreased in human PDAC, and SCRIB mislocalization was associated with poorer patient outcome. These results indicate that SCRIB deficiency enhances cancer cell survival and remodels the tumor microenvironment to accelerate PDAC development and progression, establishing the tumor suppressor function of SCRIB in advanced pancreatic cancer.

Area postrema neurons mediate interleukin-6 function in cancer cachexia.

Interleukin-6 (IL-6) has been long considered a key player in cancer cachexia. It is believed that sustained elevation of IL-6 production during cancer progression causes brain dysfunctions, which ultimately result in cachexia. However, how peripheral IL-6 influences the brain remains poorly understood. Here we show that neurons in the area postrema (AP), a circumventricular structure in the hindbrain, is a critical mediator of IL-6 function in cancer cachexia in male mice. We find that circulating IL-6 can rapidly enter the AP and activate neurons in the AP and its associated network. Peripheral tumor, known to increase circulating IL-6, leads to elevated IL-6 in the AP, and causes potentiated excitatory synaptic transmission onto AP neurons and AP network hyperactivity. Remarkably, neutralization of IL-6 in the brain of tumor-bearing mice with an anti-IL-6 antibody attenuates cachexia and the hyperactivity in the AP network, and markedly prolongs lifespan. Furthermore, suppression of Il6ra, the gene encoding IL-6 receptor, specifically in AP neurons with CRISPR/dCas9 interference achieves similar effects. Silencing Gfral-expressing AP neurons also attenuates cancer cachectic phenotypes and AP network hyperactivity. Our study identifies a central mechanism underlying the function of peripheral IL-6, which may serve as a target for treating cancer cachexia.

Pancreatic cancer-associated fibroblasts modulate macrophage differentiation via sialic acid-Siglec interactions.

Despite recent advances in cancer immunotherapy, pancreatic ductal adenocarcinoma (PDAC) remains unresponsive due to an immunosuppressive tumor microenvironment, which is characterized by the abundance of cancer-associated fibroblasts (CAFs). Once identified, CAF-mediated immune inhibitory mechanisms could be exploited for cancer immunotherapy. Siglec receptors are increasingly recognized as immune checkpoints, and their ligands, sialic acids, are known to be overexpressed by cancer cells. Here, we unveil a previously unrecognized role of sialic acid-containing glycans on PDAC CAFs as crucial modulators of myeloid cells. Using multiplex immunohistochemistry and transcriptomics, we show that PDAC stroma is enriched in sialic acid-containing glycans compared to tumor cells and normal fibroblasts, and characterized by ST3GAL4 expression. We demonstrate that sialic acids on CAF cell lines serve as ligands for Siglec-7, -9, -10 and -15, distinct from the ligands on tumor cells, and that these receptors are found on myeloid cells in the stroma of PDAC biopsies. Furthermore, we show that CAFs drive the differentiation of monocytes to immunosuppressive tumor-associated macrophages in vitro, and that CAF sialylation plays a dominant role in this process compared to tumor cell sialylation. Collectively, our findings unravel sialic acids as a mechanism of CAF-mediated immunomodulation, which may provide targets for immunotherapy in PDAC.

Cytidine deaminases APOBEC3C and APOBEC3D promote DNA replication stress resistance in pancreatic cancer cells.

Gemcitabine is a potent inhibitor of DNA replication and is a mainstay therapeutic for diverse cancers, particularly pancreatic ductal adenocarcinoma (PDAC). However, most tumors remain refractory to gemcitabine therapies. Here, to define the cancer cell response to gemcitabine, we performed genome-scale CRISPR-Cas9 chemical-genetic screens in PDAC cells and found selective loss of cell fitness upon disruption of the cytidine deaminases APOBEC3C and APOBEC3D. Following gemcitabine treatment, APOBEC3C and APOBEC3D promote DNA replication stress resistance and cell survival by deaminating cytidines in the nuclear genome to ensure DNA replication fork restart and repair in PDAC cells. We provide evidence that the chemical-genetic interaction between APOBEC3C or APOBEC3D and gemcitabine is absent in nontransformed cells but is recapitulated across different PDAC cell lines, in PDAC organoids and in PDAC xenografts. Thus, we uncover roles for APOBEC3C and APOBEC3D in DNA replication stress resistance and offer plausible targets for improving gemcitabine-based therapies for PDAC.

Modular synthesis of functional libraries by accelerated SuFEx click chemistry.

Accelerated SuFEx Click Chemistry (ASCC) is a powerful method for coupling aryl and alkyl alcohols with SuFEx-compatible functional groups. With its hallmark favorable kinetics and exceptional product yields, ASCC streamlines the synthetic workflow, simplifies the purification process, and is ideally suited for discovering functional molecules. We showcase the versatility and practicality of the ASCC reaction as a tool for the late-stage derivatization of bioactive molecules and in the array synthesis of sulfonate-linked, high-potency, microtubule targeting agents (MTAs) that exhibit nanomolar anticancer activity against multidrug-resistant cancer cell lines. These findings underscore ASCC's promise as a robust platform for drug discovery.

Prophylactic and long-lasting efficacy of senolytic CAR T cells against age-related metabolic dysfunction.

Senescent cells, which accumulate in organisms over time, contribute to age-related tissue decline. Genetic ablation of senescent cells can ameliorate various age-related pathologies, including metabolic dysfunction and decreased physical fitness. While small-molecule drugs that eliminate senescent cells ('senolytics') partially replicate these phenotypes, they require continuous administration. We have developed a senolytic therapy based on chimeric antigen receptor (CAR) T cells targeting the senescence-associated protein urokinase plasminogen activator receptor (uPAR), and we previously showed these can safely eliminate senescent cells in young animals. We now show that uPAR-positive senescent cells accumulate during aging and that they can be safely targeted with senolytic CAR T cells. Treatment with anti-uPAR CAR T cells improves exercise capacity in physiological aging, and it ameliorates metabolic dysfunction (for example, improving glucose tolerance) in aged mice and in mice on a high-fat diet. Importantly, a single administration of these senolytic CAR T cells is sufficient to achieve long-term therapeutic and preventive effects.

A mucus production programme promotes classical pancreatic ductal adenocarcinoma.

OBJECTIVE: The optimal therapeutic response in cancer patients is highly dependent upon the differentiation state of their tumours. Pancreatic ductal adenocarcinoma (PDA) is a lethal cancer that harbours distinct phenotypic subtypes with preferential sensitivities to standard therapies. This study aimed to investigate intratumour heterogeneity and plasticity of cancer cell states in PDA in order to reveal cell state-specific regulators. DESIGN: We analysed single-cell expression profiling of mouse PDAs, revealing intratumour heterogeneity and cell plasticity and identified pathways activated in the different cell states. We performed comparative analysis of murine and human expression states and confirmed their phenotypic diversity in specimens by immunolabeling. We assessed the function of phenotypic regulators using mouse models of PDA, organoids, cell lines and orthotopically grafted tumour models. RESULTS: Our expression analysis and immunolabeling analysis show that a mucus production programme regulated by the transcription factor SPDEF is highly active in precancerous lesions and the classical subtype of PDA - the most common differentiation state. SPDEF maintains the classical differentiation and supports PDA transformation in vivo. The SPDEF tumour-promoting function is mediated by its target genes AGR2 and ERN2/IRE1ß that regulate mucus production, and inactivation of the SPDEF programme impairs tumour growth and facilitates subtype interconversion from classical towards basal-like differentiation. CONCLUSIONS: Our findings expand our understanding of the transcriptional programmes active in precancerous lesions and PDAs of classical differentiation, determine the regulators of mucus production as specific vulnerabilities in these cell states and reveal phenotype switching as a response mechanism to inactivation of differentiation states determinants.

Engrailed-1 Promotes Pancreatic Cancer Metastasis.

Engrailed-1 (EN1) is a critical homeodomain transcription factor (TF) required for neuronal survival, and EN1 expression has been shown to promote aggressive forms of triple negative breast cancer. Here, it is reported that EN1 is aberrantly expressed in a subset of pancreatic ductal adenocarcinoma (PDA) patients with poor outcomes. EN1 predominantly repressed its target genes through direct binding to gene enhancers and promoters, implicating roles in the activation of MAPK pathways and the acquisition of mesenchymal cell properties. Gain- and loss-of-function experiments demonstrated that EN1 promoted PDA transformation and metastasis in vitro and in vivo. The findings nominate the targeting of EN1 and downstream pathways in aggressive PDA.

Prophylactic and long-lasting efficacy of senolytic CAR T cells against age-related metabolic dysfunction.

Senescent cells accumulate in organisms over time because of tissue damage and impaired immune surveillance and contribute to age-related tissue decline1,2. In agreement, genetic ablation studies reveal that elimination of senescent cells from aged tissues can ameliorate various age-related pathologies, including metabolic dysfunction and decreased physical fitness3-7. While small-molecule drugs capable of eliminating senescent cells (known as 'senolytics') partially replicate these phenotypes, many have undefined mechanisms of action and all require continuous administration to be effective. As an alternative approach, we have developed a cell-based senolytic therapy based on chimeric antigen receptor (CAR) T cells targeting uPAR, a cell-surface protein upregulated on senescent cells, and previously showed these can safely and efficiently eliminate senescent cells in young animals and reverse liver fibrosis8. We now show that uPAR-positive senescent cells accumulate during physiological aging and that they can be safely targeted with senolytic CAR T cells. Treatment with anti uPAR CAR T cells ameliorates metabolic dysfunction by improving glucose tolerance and exercise capacity in physiological aging as well as in a model of metabolic syndrome. Importantly, a single administration of a low dose of these senolytic CAR T cells is sufficient to achieve long-term therapeutic and preventive effects.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

SUMMARY: Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

AACR Cancer Centers Alliance: Fostering Collaboration and Innovation to Advance Lifesaving Scientific Discoveries for Patients.

SUMMARY: Basic and clinical cancer research discoveries stemming from the nation's cancer centers have markedly improved outcomes for many cancer patients. Despite this forward momentum in our progress against this complex disease, cancer in all its forms remains a major public health challenge that touches the lives of nearly every American, either directly or indirectly. The newly formed AACR Cancer Centers Alliance will accelerate the pace of discovery by providing an ongoing mechanism for transferring new knowledge, sharing resources, developing national demonstration projects, and driving innovation that impacts cancer science, cancer care delivery, and science and health policy.

Myo-differentiation reporter screen reveals NF-Y as an activator of PAX3-FOXO1 in rhabdomyosarcoma.

Recurrent chromosomal rearrangements found in rhabdomyosarcoma (RMS) produce the PAX3-FOXO1 fusion protein, which is an oncogenic driver and a dependency in this disease. One important function of PAX3-FOXO1 is to arrest myogenic differentiation, which is linked to the ability of RMS cells to gain an unlimited proliferation potential. Here, we developed a phenotypic screening strategy for identifying factors that collaborate with PAX3-FOXO1 to block myo-differentiation in RMS. Unlike most genes evaluated in our screen, we found that loss of any of the three subunits of the Nuclear Factor Y (NF-Y) complex leads to a myo-differentiation phenotype that resembles the effect of inactivating PAX3-FOXO1. While the transcriptomes of NF-Y- and PAX3-FOXO1-deficient RMS cells bear remarkable similarity to one another, we found that these two transcription factors occupy nonoverlapping sites along the genome: NF-Y preferentially occupies promoters, whereas PAX3-FOXO1 primarily binds to distal enhancers. By integrating multiple functional approaches, we map the PAX3 promoter as the point of intersection between these two regulators. We show that NF-Y occupies CCAAT motifs present upstream of PAX3 to function as a transcriptional activator of PAX3-FOXO1 expression in RMS. These findings reveal a critical upstream role of NF-Y in the oncogenic PAX3-FOXO1 pathway, highlighting how a broadly essential transcription factor can perform tumor-specific roles in governing cellular state.

Optogenetic stimulation of the brainstem dorsal motor nucleus ameliorates acute pancreatitis.

Introduction: Inflammation is an inherently self-amplifying process, resulting in progressive tissue damage when unresolved. A brake on this positive feedback system is provided by the nervous system which has evolved to detect inflammatory signals and respond by activating anti-inflammatory processes, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve. Acute pancreatitis, a common and serious condition without effective therapy, develops when acinar cell injury activates intrapancreatic inflammation. Prior study has shown that electrical stimulation of the carotid sheath, which contains the vagus nerve, boosts the endogenous anti-inflammatory response and ameliorates acute pancreatitis, but it remains unknown whether these anti-inflammatory signals originate in the brain. Methods: Here, we used optogenetics to selectively activate efferent vagus nerve fibers originating in the brainstem dorsal motor nucleus of the vagus (DMN) and evaluated the effects on caerulein-induced pancreatitis. Results: Stimulation of the cholinergic neurons in the DMN significantly attenuates the severity of pancreatitis as indicated by reduced serum amylase, pancreatic cytokines, tissue damage, and edema. Either vagotomy or silencing cholinergic nicotinic receptor signaling by pre-administration of the antagonist mecamylamine abolishes the beneficial effects. Discussion: These results provide the first evidence that efferent vagus cholinergic neurons residing in the brainstem DMN can inhibit pancreatic inflammation and implicate the cholinergic anti-inflammatory pathway as a potential therapeutic target for acute pancreatitis.

Inhibition of mitochondrial metabolism by (-)-jerantinine A: synthesis and biological studies in triple-negative breast cancer cells.

A concise semi-synthesis of the Aspidosperma alkaloids, (-)-jerantinine A and (-)-melodinine P, and derivatives thereof, is reported. The novel compounds were shown to have potent activity against MDA-MB-231 triple-negative breast cancer cells. Furthermore, unbiased metabolomics and live cell reporter assays reveal (-)-jerantinine A alters cellular redox metabolism and induces oxidative stress that coincides with cell cycle arrest.