RESUMO
Polo-like kinase 1 (PLK1) is a serine/threonine kinase required for mitosis and cytokinesis. As cancer cells are often hypersensitive to partial PLK1 inactivation, chemical inhibitors of PLK1 have been developed and tested in clinical trials. However, these small molecule inhibitors alone are not completely effective. PLK1 promotes numerous molecular and cellular events in the cell division cycle and it is unclear which of these events most crucially depend on PLK1 activity. We used a CRISPR-based genome-wide screening strategy to identify genes whose inactivation enhances cell proliferation defects upon partial chemical inhibition of PLK1. Genes identified encode proteins that are functionally linked to PLK1 in multiple ways, most notably factors that promote centromere and kinetochore function. Loss of the kinesin KIF18A or the outer kinetochore protein SKA1 in PLK1-compromised cells resulted in mitotic defects, activation of the spindle assembly checkpoint and nuclear reassembly defects. We also show that PLK1-dependent CENP-A loading at centromeres is extremely sensitive to partial PLK1 inhibition. Our results suggest that partial inhibition of PLK1 compromises the integrity and function of the centromere/kinetochore complex, rendering cells hypersensitive to different kinetochore perturbations. We propose that KIF18A is a promising target for combinatorial therapies with PLK1 inhibitors.
Assuntos
Proteínas de Ciclo Celular , Elementos Facilitadores Genéticos , Cinetocoros , Proteínas Serina-Treonina Quinases , Proteínas de Ciclo Celular/genética , Proteínas Serina-Treonina Quinases/genética , Humanos , Quinase 1 Polo-LikeRESUMO
Improving the tumor reoxygenation to sensitize the tumor to radiation therapy is a cornerstone in radiation oncology. Here, the pre-clinical development of a clinically transferable liposomal formulation encapsulating trans sodium crocetinate (NP TSC) is reported to improve oxygen diffusion through the tumor environment. Early pharmacokinetic analysis of the clinical trial of this molecule performed on 37 patients orient to define the optimal fixed dosage to use in a triple-negative breast cancer model to validate the therapeutic combination of radiation therapy and NP TSC. Notably, it is reported that this formulation is non-toxic in both humans and mice at the defined fixed concentration, provides a normalization of the tumor vasculature within 72 h window after systemic injection, leads to a transient increase (50% improvement) in the tumor oxygenation, and significantly improves the efficacy of both mono-fractionated and fractionated radiation therapy treatment. Together, these findings support the introduction of a first-in-class therapeutic construct capable of tumor-specific reoxygenation without associated toxicities.
Assuntos
Neoplasias , Hipóxia Tumoral , Humanos , Camundongos , Animais , Carotenoides , Neoplasias/terapia , Vitamina A/uso terapêuticoRESUMO
BACKGROUND: Immune checkpoint inhibitors of programmed cell death protein 1 (PD-1) represent a significant breakthrough in treating head and neck squamous cell carcinoma (HNSCC), with long-lasting responses and prolonged survival observed in first- and second-line therapy. However, this is observed in < 20% of patients and high primary/secondary resistance may occur. The primary objective of the identification of predictive factors for the response to anti-PD-1 immunotherapy in head and neck squamous cell carcinoma (IPRICE) study is to identify predictive factors of response to anti-PD-1 immunotherapy. METHODS: The IPRICE study is a single-center, prospective, non-randomized, open-label, and interventional clinical trial. Liquid and tumor biopsies will be performed in 54 patients with recurrent/metastatic (R/M) HNSCC undergoing anti-PD-1 immunotherapy alone to compare the evolution of gene expression and immunological profile between responders and non-responders. We will use a multidisciplinary approach including spatial transcriptomics, single seq-RNA analysis, clinical data, and medical images. Genes, pathways, and transcription factors potentially involved in the immune response will also be analyzed, including genes involved in the interferon-gamma (IFN-γ) pathway, immunogenic cell death and mitophagy, hypoxia, circulating miRNA-mediated immunomodulation, cytokines, and immune repertoire within the tumor microenvironment (TME). With a follow-up period of 3-years, these data will help generate effective biomarkers to define optimal therapeutic strategy and new immunomodulatory agents based on a better understanding of primary/secondary resistance mechanisms. Tumor biopsy will be performed initially before the start of immunotherapy at the first tumor assessment and is only proposed at tumor progression. Clinical data will be collected using a dedicated Case Report Form (CRF). DISCUSSION: Identifying predictive factors of the response to anti-PD-1 immunotherapy and optimizing long-term immune response require a thorough understanding of the intrinsic and acquired resistance to immunotherapy. To achieve this, dynamic profiling of TME during anti-PD-1 immunotherapy based on analysis of tumor biopsy samples is critical. This will be accomplished through the anatomical localization of HNSCC, which will allow for the analysis of multiple biopsies during treatment and the emergence of breakthrough technologies including single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics. TRIAL REGISTRATION: Clinicaltrial.gov. Registered April 14, 2022, https://www. CLINICALTRIALS: gov/study/NCT05328024 .
Assuntos
Neoplasias de Cabeça e Pescoço , Inibidores de Checkpoint Imunológico , Recidiva Local de Neoplasia , Carcinoma de Células Escamosas de Cabeça e Pescoço , Humanos , Antígeno B7-H1/metabolismo , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Imunoterapia/métodos , Estudos Prospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Microambiente Tumoral , Inibidores de Checkpoint Imunológico/uso terapêuticoRESUMO
Current therapeutic treatments improving the impaired transportation of oxygen in acute respiratory distress syndrome (ARDS) have been found to be relevant and beneficial for the therapeutic treatment of COVID-19 patients suffering from severe respiratory complications. Hence, we report the preclinical and the preliminary results of the Phase I/II clinical trial of LEAF-4L6715, a liposomal nanocarrier encapsulating the kosmotropic agent trans-crocetin (TC), which, once injected, enhance the oxygenation of vascular tissue and therefore has the potential to improve the clinical outcomes of ARDS and COVID-19 in severely impacted patients. We demonstrated that the liposomal formulation enabled to increase from 30 min to 48 h the reoxygenation properties of free TCs in vitro in endothelial cells, but also to improve the half-life of TC by 6-fold in healthy mice. Furthermore, we identified 25 mg/kg as the maximum tolerated dose in mice. This determined concentration led to the validation of the therapeutic efficacy of LEAF-4 L6715 in a sepsis mouse model. Finally, we report the preliminary outcomes of an open-label multicenter Phase I/II clinical trial (EudraCT 2020-001393-30; NCT04378920), which was aimed to define the appropriate schedule and dosage of LEAF-4L6715 and to confirm its tolerability profile and preliminary clinical activity in COVID-19 patients treated in intensive care unit.
Assuntos
COVID-19 , Síndrome do Desconforto Respiratório , Animais , Carotenoides , Células Endoteliais , Humanos , Camundongos , Respiração Artificial , Síndrome do Desconforto Respiratório/tratamento farmacológico , SARS-CoV-2 , Vitamina A/análogos & derivadosRESUMO
Certain amino acids induce inhibitory effects in plant growth due to feedback inhibition of metabolic pathways. The inhibition patterns depend on plant species and the plant developmental stage. Those amino acids with inhibitory action on specific weeds could be utilized as herbicides, however, their use for weed control has not been put into practice. Orobanche minor is a weed that parasitizes red clover. O. minor germination is stimulated by clover root exudates. The subsequent seedling is an obligated parasite that must attach quickly to the clover root to withdraw its nutrients. Early development of O. minor is vulnerable to amino acid inhibition and therefore, a series of in vitro, rhizotron, and field experiments were conducted to investigate the potential of amino acids to inhibit O. minor parasitism. In in vitro experiments it was found that among a collection of 20 protein amino acids, lysine, methionine and tryptophan strongly interfere with O. minor early development. Field research confirmed their inhibitory effect but revealed that methionine was more effective than lysine and tryptophan, and that two successive methionine applications at 308 and 543 growing degree days inhibited O. minor emergence in red clover up to 67%. We investigated additional effects with potential to influence the practical use of amino acids against broomrape weeds, whether the herbicidal effect may be reversible by other amino acids exuded by host plants or may be amplified by inducing host resistance barriers against O. minor penetration. This paper suggests that amino acids may have the potential to be integrated into biorational programs of broomrape management.
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Social spiders differ from social insects by the production and the use of silk to build irregular webs. This silk prevents dispersion of the individuals and ensures the group cohesion during swarming and collective displacements, playing a part similar to tracks of pheromones in ants. A social spider Anelosimus eximius is attracted by conspecific silk and does not show any discrimination relative to its origin, excluding any group closure. The quantity of silk and the state of satiety of the individual modulate this attraction, and might explain how the spider society adapts the size of the web to its nutritional needs.