Re-purposing the pro-senescence properties of doxorubicin to introduce immunotherapy in breast cancer brain metastasis

An increasing number of breast cancer patients develop brain metastases (BM). Standard-of-care treatments are largely inefficient, and breast cancer brain metastasis (BCBM) patients are considered untreatable. Immunotherapies are not successfully employed in BCBM, in part because breast cancer is a “cold” tumor and also because the brain tissue has a unique immune landscape. Here, we generate and characterize immunocompetent models of BCBM derived from PyMT and Neu mammary tumors to test how harnessing the pro-senescence properties of doxorubicin can be used to prime the specific immune BCBM microenvironment. We reveal that BCBM senescent cells, induced by doxorubicin, trigger the recruitment of PD1-expressing T cells to the brain. Importantly, we demonstrate that induction of senescence with doxorubicin improves the efficacy of immunotherapy with anti-PD1 in BCBM in a CD8 T cell-dependent manner, thereby providing an optimized strategy to introduce immune-based treatments in this lethal disease. In addition, our BCBM models can be used for pre-clinical testing of other therapeutic strategies in the future

Taxanes trigger cancer cell killing in vivo by inducing non-canonical T cell cytotoxicity

Although treatment with taxanes does not always lead to clinical benefit, all patients are at risk of their detrimental side effects such as peripheral neuropathy. Understanding the in vivo mode of action of taxanes can help design improved treatment regimens. Here, we demonstrate that in vivo, taxanes directly trigger T cells to selectively kill cancer cells in a non-canonical, T cell receptor-independent manner. Mechanistically, taxanes induce T cells to release cytotoxic extracellular vesicles, which lead to apoptosis specifically in tumor cells while leaving healthy epithelial cells intact. We exploit these findings to develop an effective therapeutic approach, based on transfer of T cells pre-treated with taxanes ex vivo, thereby avoiding toxicity of systemic treatment. Our study reveals a different in vivo mode of action of one of the most commonly used chemotherapies, and opens avenues to harness T cell-dependent anti-tumor effects of taxanes while avoiding systemic toxicity

Taxanes trigger cancer cell killing in vivo by inducing non-canonical T cell cytotoxicity

Although treatment with taxanes does not always lead to clinical benefit, all patients are at risk of their detrimental side effects such as peripheral neuropathy. Understanding the in vivo mode of action of taxanes can help design improved treatment regimens. Here, we demonstrate that in vivo, taxanes directly trigger T cells to selectively kill cancer cells in a non-canonical, T cell receptor-independent manner. Mechanistically, taxanes induce T cells to release cytotoxic extracellular vesicles, which lead to apoptosis specifically in tumor cells while leaving healthy epithelial cells intact. We exploit these findings to develop an effective therapeutic approach, based on transfer of T cells pre-treated with taxanes ex vivo, thereby avoiding toxicity of systemic treatment. Our study reveals a different in vivo mode of action of one of the most commonly used chemotherapies, and opens avenues to harness T cell-dependent anti-tumor effects of taxanes while avoiding systemic toxicity

Cell polarity in hepatic cells physiopathology

La polarité apico-basolatérale, qui est essentielle pour le maintien de l'architecture tissulaire et pour des fonctions de l'épithelium sain, est fréquemment fragilisée, voire perdue, dans des lésions prénéoplasiques et au cours de la tumorigénèse. Les patients atteints de l'hépatite C chronique ont un risque accru de développer des carcinomes hépatocellulaires. Le contexte inflammatoire et cirrhotique, caractéristique de l'infection chronique par le virus de l'hépatite C (VHC), constitue un facteur de risque important de la tumorigenèse. De plus, le virus exerce des effets directs sur la physiopathologie de la cellule hôte, qui semblent favoriser la transformation oncogénique. Mon travail de thèse a permit de développer et de caractériser un modèle de culture tridimensionnelle qui reproduit la morphologie complexe des hépatocytes pour ensuite étudier l'effet d'une proteine virale, NS5A sur la physiopathologie de cellules hépatiques dans un contexte tridimensionnelle. Des cellules hépatiques, immortalisées ou primaires, s'organisent en organoides polarisés et acquièrent l'expression de marqueurs hépatocytaires matures. L'organisation tridimensionnelle et la polarité des organoides influent sur des voies de signalisation intracellulaires, dont la voie PI3K/Akt, un acteur crucial de la physiologie de la cellule et de sa transformation. Dans notre modèle, l'activation constitutive de la kinase Akt perturbe l'organisation tridimensionnelle des hépatocytes. NS5A, une des protéines du VHC, active la voie PI3K/Akt et interfère avec l'intégrité des organoides. Dans des précurseurs hépatiques primaires, les BMELs l'expression de NS5A conduit à la perte de marqueurs épithéliaux et à l'acquisition de marqueurs mésenchymateux et au phénotype migratoire et invasif. Ces effets de NS5A, qui suggèrent une transition épithelio-mésenchymateuse (TEM), sont additifs à l'action du TGF-β, un inducteur connu de la TEM.Apico-basolateral polarity is essential to maintain tissue architecture and function of healthy epithelium. It is weakened or lost in preneoplastic lesions and in the course of carcinogenesis. Patients suffering from chronic hepatitis C are at risk for hepatocellular carcinoma. In addition to the necroinflammatory liver microenvironment, which favours tumorigenesis, direct effects of the virus on its host cell physiopathology also participate in the initiation of oncogenic transformation.To study the effects of viral proteins on cellular polarity and function, we developped an in vitro threedimensional (3D) culture model that reproduces complex hepatocyte morphology. Both immortalized cells and primary hepatocyte precursors organise themselves into intricate 3D organoids and acquire markers of mature hepatocytes. Their organisation and polarity impacts on several intracellular signal transduction pathways, including the PI3K/Akt axis, a major actor of physiology and of oncogenic transformation. Interestingly, constitutive Akt signalling perturbs hepatocyte 3D organization.NS5A, an HCV viral protein with pleiotropic activities, is an upstream activator of Akt. NS5A expression interferes with organoid formation and integrity. In primary hepatocyte precursors it leads to downregulation of epithelial and to acquisition of mesenchymal markers, suggesting an induction of epithelial-to-mesenchymal transition (EMT). Moreover, the effects of NS5A are additive to that of TGF-beta, a bona fide EMT inducer relevant to HCV-related pathologies. NS5A is also inducing pro-migratory and invasive phenotypes in BMEL cells as well as the hepatic cell line AML12. The signaling pahways underlying this results might involve Twist factors, well known actors of EMT, as NS5A is capable of their transcriptional regulation.The molecular mechanisms linking viral proteins to alterations of hepatocyte morphology are under investigation. Alterations of cell shape and function are of major interest in the context of virus-induced phenotype, relevant to tumour initiation and progression

Primary Pleuropulmonary Synovial Sarcoma: A Case

Primary pleuropulmonary synovial sarcoma is extremely rare. The diagnosis can only be made after having eliminated an extrapleuropulmonary localization in the past and at the time of diagnosis. Our presentation is about a 40-year-old woman having a cough and dyspnea since three weeks ago; imaging had showed a left pleurisy with pleuropulmonary process. Histological study of the biopsy confirmed the diagnosis of pleuropulmonary synovial sarcoma. PET-SCAN had not identified any extrathoracic localization. This tumor is known for its aggressive nature and high risk of metastasis. Its primitive character is retained following a diagnostic procedure of exclusion. Surgical treatment remains the best therapeutic tool when it is technically feasible; otherwise the prognosis is often unfortunate. In this paper, we report a case of primary pleuropulmonary synovial sarcoma. Through this case, we present a rare disease that is often difficult to diagnose

Early Therapeutic Interventions for Newly Diagnosed Glioblastoma: Rationale and Review of the Literature

PURPOSE OF REVIEW: Glioblastoma is the commonest primary brain cancer in adults whose outcomes are amongst the worst of any cancer. The current treatment pathway comprises surgery and postoperative chemoradiotherapy though unresectable diffusely infiltrative tumour cells remain untreated for several weeks post-diagnosis. Intratumoural heterogeneity combined with increased hypoxia in the postoperative tumour microenvironment potentially decreases the efficacy of adjuvant interventions and fails to prevent early postoperative regrowth, called rapid early progression (REP). In this review, we discuss the clinical implications and biological foundations of post-surgery REP. Subsequently, clinical interventions potentially targeting this phenomenon are reviewed systematically. RECENT FINDINGS: Early interventions include early systemic chemotherapy, neoadjuvant immunotherapy, local therapies delivered during surgery (including Gliadel wafers, nanoparticles and stem cell therapy) and several radiotherapy techniques. We critically appraise and compare these strategies in terms of their efficacy, toxicity, challenges and potential to prolong survival. Finally, we discuss the most promising strategies that could benefit future glioblastoma patients. SUMMARY: There is biological rationale to suggest that early interventions could improve the outcome of glioblastoma patients and they should be investigated in future trials

A Carbon Nanotube Optical Reporter Maps Endolysosomal Lipid Flux

Lipid accumulation within the lumen of endolysosomal vesicles is observed in various pathologies including atherosclerosis, liver disease, neurological disorders, lysosomal storage disorders, and cancer. Current methods cannot measure lipid flux specifically within the lysosomal lumen of live cells. We developed an optical reporter, composed of a photoluminescent carbon nanotube of a single chirality, that responds to lipid accumulation via modulation of the nanotube’s optical band gap. The engineered nanomaterial, composed of short, single-stranded DNA and a single nanotube chirality, localizes exclusively to the lumen of endolysosomal organelles without adversely affecting cell viability or proliferation or organelle morphology, integrity, or function. The emission wavelength of the reporter can be spatially resolved from within the endolysosomal lumen to generate quantitative maps of lipid content in live cells. Endolysosomal lipid accumulation in cell lines, an example of drug-induced phospholipidosis, was observed for multiple drugs in macrophages, and measurements of patient-derived Niemann–Pick type C fibroblasts identified lipid accumulation and phenotypic reversal of this lysosomal storage disease. Single-cell measurements using the reporter discerned subcellular differences in equilibrium lipid content, illuminating significant intracellular heterogeneity among endolysosomal organelles of differentiating bone-marrow-derived monocytes. Single-cell kinetics of lipoprotein-derived cholesterol accumulation within macrophages revealed rates that differed among cells by an order of magnitude. This carbon nanotube optical reporter of endolysosomal lipid content in live cells confers additional capabilities for drug development processes and the investigation of lipid-linked diseases