8 research outputs found
Physical Activity as the Best Supportive Care in Cancer: The Clinician’s and the Researcher’s Perspectives
International audienceMultidisciplinary supportive care, integrating the dimensions of exercise alongside oncological treatments, is now regarded as a new paradigm to improve patient survival and quality of life. Its impact is important on the factors that control tumor development, such as the immune system, inflammation, tissue perfusion, hypoxia, insulin resistance, metabolism, glucocorticoid levels, and cachexia. An increasing amount of research has been published in the last years on the effects of physical activity within the framework of oncology, marking the appearance of a new medical field, commonly known as “exercise oncology”. This emerging research field is trying to determine the biological mechanisms by which, aerobic exercise affects the incidence of cancer, the progression and/or the appearance of metastases. We propose an overview of the current state of the art physical exercise interventions in the management of cancer patients, including a pragmatic perspective with tips for routine practice. We then develop the emerging mechanistic views about physical exercise and their potential clinical applications. Moving toward a more personalized, integrated, patient-centered, and multidisciplinary management, by trying to understand the different interactions between the cancer and the host, as well as the impact of the disease and the treatments on the different organs, this seems to be the most promising method to improve the care of cancer patients
The immunological landscape in pancreatic ductal adenocarcinoma and overcoming resistance to immunotherapy
International audiencePancreatic ductal adenocarcinoma is associated with a poor prognosis and there are few treatment options. The development of immunotherapy in pancreatic ductal adenocarcinoma has been difficult, and immune checkpoint inhibitors are only effective in a very small subset of patients. Most obstacles for treatment have been related to intertumoural and intratumoural heterogeneity, the composition of tumour stroma, and crosstalk with cancer cells. Improved molecular characterisation of pancreatic ductal adenocarcinoma and a better understanding of its microenvironment have paved the way for novel immunotherapy strategies, including the identification of predictive biomarkers, the development of rational combinations to optimise effectiveness, and the targeting of new mechanisms. Future immunotherapy strategies should consider individual characteristics to move beyond the traditional immune targets and circumvent the resistance to therapies that have been developed so far
Generation of a conditional Flpo/FRT mouse model expressing constitutively active TGFβ in fibroblasts
International audienceTransforming growth factor (TGFβ) is a secreted factor, which accumulates in tissues during many physio- and pathological processes such as embryonic development, wound healing, fibrosis and cancer. In order to analyze the effects of increased microenvironmental TGFβ concentration in vivo, we developed a conditional transgenic mouse model (Flpo/Frt system) expressing bioactive TGFβ in fibroblasts, a cell population present in the microenvironment of almost all tissues. To achieve this, we created the genetically-engineered [Fsp1-Flpo; FSFTGFβCA] mouse model. The Fsp1-Flpo allele consists in the Flpo recombinase under the control of the Fsp1 (fibroblast-specific promoter 1) promoter. The FSFTGFβCA allele consists in a transgene encoding a constitutively active mutant form of TGFβ (TGFβCA) under the control of a Frt-STOP-Frt (FSF) cassette. The FSFTGFβCA allele was created to generate this model, and functionally validated by in vitro, ex vivo and in vivo techniques. [Fsp1-Flpo; FSFTGFβCA] animals do not present any obvious phenotype despite the correct expression of TGFβCA transgene in fibroblasts. This [Fsp1-Flpo; FSFTGFβCA] model is highly pertinent for future studies on the effect of increased microenvironmental bioactive TGFβ concentrations in mice bearing Cre-dependent genetic alterations in other compartments (epithelial or immune compartments for instance). These dual recombinase system (DRS) approaches will enable scientists to study uncoupled spatiotemporal regulation of different genetic alterations within the same mouse, thus better replicating the complexity of human diseases
Hypothalamic–pituitary–adrenal axis activation and glucocorticoid-responsive gene expression in skeletal muscle and liver of Apc mice
International audienceBackground: Cancer patients at advanced stages experience a severe depletion of skeletal muscle compartment together with a decrease in muscle function, known as cancer cachexia. Cachexia contributes to reducing quality of life, treatment efficiency, and lifespan of cancer patients. However, the systemic nature of the syndrome is poorly documented. Here, we hypothesize that glucocorticoids would be important systemic mediators of cancer cachexia. Methods: To explore the role of glucocorticoids during cancer cachexia, biomolecular analyses were performed on several tissues (adrenal glands, blood, hypothalamus, liver, and skeletal muscle) collected from Apc Min/+ male mice, a mouse model of intestine and colon cancer, aged of 13 and 23 weeks, and compared with wild type age-matched C57BL/6J littermates. Results: Twenty-three-week-old Apc mice recapitulated important features of cancer cachexia including body weight loss (À16%, P < 0.0001), muscle atrophy (gastrocnemius muscle: À53%, P < 0.0001), and weakness (À50% in tibialis anterior muscle force, P < 0.0001), increased expression of atrogens (7-fold increase in MuRF1 transcript level, P < 0.0001) and down-regulation of Akt-mTOR pathway (3.3-fold increase in 4EBP1 protein content, P < 0.0001), together with a marked transcriptional rewiring of hepatic metabolism toward an increased expression of gluconeogenic genes (Pcx
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Multicenter randomized controlled trial of neoadjuvant chemoradiotherapy alone or in combination with pembrolizumab in patients with resectable or borderline resectable pancreatic adenocarcinoma
BackgroundPancreatic ductal adenocarcinoma (PDAC) is a challenging target for immunotherapy because it has an immunosuppressive tumor microenvironment. Neoadjuvant chemoradiotherapy can increase tumor-infiltrating lymphocyte (TIL) density, which may predict overall survival (OS). We hypothesized that adding programmed cell death protein 1 (PD-1) blockade to chemoradiotherapy would be well tolerated and increase TILs among patients with localized PDAC.MethodsPatients were randomized 2:1 to Arm A (receiving pembrolizumab plus chemoradiotherapy (capecitabine and external beam radiation)) or Arm B (receiving chemoradiotherapy alone) before anticipated pancreatectomy. Primary endpoints were (1) incidence and severity of adverse events during neoadjuvant therapy and (2) density of TILs in resected tumor specimens. TIL density was assessed using multiplexed immunofluorescence histologic examination.ResultsThirty-seven patients were randomized to Arms A (n=24) and B (n=13). Grade ≥3 adverse events related to neoadjuvant treatment were experienced by 9 (38%) and 4 (31%) patients in Arms A and B, respectively, with one patient experiencing dose-limiting toxicity in Arm A. Seventeen (71%) and 7 (54%) patients in Arms A and B, respectively, underwent pancreatectomy. Median CD8+ T-cell densities in Arms A and B were 67.4 (IQR: 39.2–141.8) and 37.9 (IQR: 22.9–173.4) cells/mm2, respectively. Arms showed no noticeable differences in density of CD8+Ki67+, CD4+, or CD4+FOXP3+ regulatory T cells; M1-like and M2-like macrophages; or granulocytes. Median OS durations were 27.8 (95% CI: 17.1 to NR) and 24.3 (95% CI: 12.6 to NR) months for Arms A and B, respectively.ConclusionsAdding pembrolizumab to neoadjuvant chemoradiotherapy was safe. However, no convincing effect on CD8+ TILs was observed
SMAD2/3 mediate oncogenic effects of TGF-β in the absence of SMAD4
International audienceTGF-β signaling is involved in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis, representing one of the four major pathways genetically altered in 100% of PDAC cases. TGF-β exerts complex and pleiotropic effects in cancers, notably via the activation of SMAD pathways, predominantly SMAD2/3/4. Though SMAD2 and 3 are rarely mutated in cancers, SMAD4 is lost in about 50% of PDAC, and the role of SMAD2/3 in a SMAD4-null context remains understudied. We herein provide evidence of a SMAD2/3 oncogenic effect in response to TGF-β1 in SMAD4-null human PDAC cancer cells. We report that inactivation of SMAD2/3 in SMAD4-negative PDAC cells compromises TGF-β-driven collective migration mediated by FAK and Rho/Rac signaling. Moreover, RNA-sequencing analyses highlight a TGF-β gene signature related to aggressiveness mediated by SMAD2/3 in the absence of SMAD4. Using a PDAC patient cohort, we reveal that SMAD4-negative tumors with high levels of phospho-SMAD2 are more aggressive and have a poorer prognosis. Thus, loss of SMAD4 tumor suppressive activity in PDAC leads to an oncogenic gain-of-function of SMAD2/3, and to the onset of associated deleterious effects
Schwann cells support oncogenic potential of pancreatic cancer cells through TGFβ signaling
International audiencePancreatic ductal adenocarcinoma (PDAC) is one of the solid tumors with the poorest prognosis. The stroma of this tumor is abundant and composed of extracellular matrix and stromal cells (including cancer-associated fibroblasts and immune cells). Nerve fibers invading this stroma represent a hallmark of PDAC, involved in neural remodeling, which participates in neuropathic pain, cancer cell dissemination and tumor relapse after surgery. Pancreatic cancer-associated neural remodeling is regulated through functional interplays mediated by physical and molecular interactions between cancer cells, nerve cells and surrounding Schwann cells, and other stromal cells. In the present study, we show that Schwann cells (glial cells supporting peripheral neurons) can enhance aggressiveness (migration, invasion, tumorigenicity) of pancreatic cancer cells in a transforming growth factor beta (TGFβ)-dependent manner. Indeed, we reveal that conditioned medium from Schwann cells contains high amounts of TGFβ able to activate the TGFβ-SMAD signaling pathway in cancer cells. We also observed in human PDAC samples that high levels of TGFβ signaling activation were positively correlated with perineural invasion. Secretome analyses by mass spectrometry of Schwann cells and pancreatic cancer cells cultured alone or in combination highlighted the central role of TGFβ in neuro-epithelial interactions, as illustrated by proteomic signatures related to cell adhesion and motility. Altogether, these results demonstrate that Schwann cells are a meaningful source of TGFβ in PDAC, which plays a crucial role in the acquisition of aggressive properties by pancreatic cancer cells
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PD-1 blockade induces reactivation of non-productive T cell responses characterized by NF-kB signaling in patients with pancreatic cancer
Abstract Purpose: Pancreatic ductal adenocarcinoma (PDAC) trials have evaluated CTLA-4 and/or PD-(L)1 blockade in patients with advanced disease where bulky tumor burden and limited time to develop anti-tumor T cells may have contributed to poor clinical efficacy. Here we evaluated peripheral blood and tumor T cells from patients with PDAC receiving neoadjuvant chemoradiation plus anti-PD-1 (pembrolizumab) versus chemoradiation alone. We analyzed whether PD-1 blockade successfully reactivated T cells in the blood and/or tumor to determine whether lack of clinical benefit could be explained by lack of reactivated T cells versus other factors. Experimental Design: We used single cell transcriptional profiling and TCR clonotype tracking to identify TCR clonotypes from blood that match clonotypes in the tumor. Results: PD-1 blockade increases the flux of TCR clonotypes entering cell cycle and induces an IFNγ signature like that seen in patients with other GI malignancies who respond to PD-1 blockade. However, these reactivated T cells have a robust signature of NF-κB signaling not seen in cases of PD-1 antibody response. Among paired samples between blood and tumor, several of the newly cycling clonotypes matched activated T cell clonotypes observed in the tumor. Conclusions: Cytotoxic T cells in the blood of PDAC patients remain sensitive to reinvigoration by PD-1 blockade and some have tumor-recognizing potential. Although these T cells proliferate and have a signature of IFN exposure, they also upregulate NF-κB signaling, which potentially counteracts the beneficial effects of anti-PD-1 reinvigoration and marks these T cells as non-productive contributors to anti-tumor immunity