Periostin Limits Tumor Response to VEGFA Inhibition

Resistance to antiangiogenic drugs limits their applicability in cancer therapy. Here, we show that revascularization and progression of pancreatic neuroendocrine tumors (PNETs) under extended vascular-endothelial growth factor A (VEGFA) blockade are dependent on periostin (POSTN), a matricellular protein expressed by stromal cells. Genetic deletion of Postn in RIP1-Tag2 mice blunted tumor rebounds of M2-like macrophages and αSMA+ stromal cells in response to prolonged VEGFA inhibition and suppressed PNET revascularization and progression on therapy. POSTN deficiency also impeded the upregulation of basic fibroblast growth factor (FGF2), an adaptive mechanism previously implicated in PNET evasion from antiangiogenic therapy. Higher POSTN expression correlated with markers of M2-like macrophages in human PNETs, and depleting macrophages with a colony-stimulating factor 1 receptor (CSF1R) antibody inhibited PNET revascularization and progression under VEGFA blockade despite continued POSTN production. These findings suggest a role for POSTN in orchestrating resistance to anti-VEGFA therapy in PNETs.

Dual angiopoietin-2 and VEGFA inhibition elicits antitumor immunity that is enhanced by PD-1 checkpoint blockade

Antonino Cassarà, Michele De Palma, Ece Kadioglu, Damya Laoui, Nicolo Rigamonti, Céline Wyser Rmili

Pathological angiogenesis is a hallmark of cancer and a therapeutic target. Vascular endothelial growth factor A (VEGFA) and angiopoietin-2 (ANGPT2; also known as ANG2) are proangiogenic cytokines that sustain tumor angiogenesis and limit antitumor immunity. We show that combined ANGPT2 and VEGFA blockade by a bispecific antibody (A2V) provided superior therapeutic benefits, as compared to the single agents, in both genetically engineered and transplant tumor models, including metastatic breast cancer (MMTV-PyMT), pancreatic neuroendocrine tumor (RIP1-Tag2), and melanoma. Mechanistically, A2V promoted vascular regression, tumor necrosis, and antigen presentation by intratumoral phagocytes. A2V also normalized the remaining blood vessels and facilitated the extravasation and perivascular accumulation of activated, interferon-γ (IFNγ)–expressing CD8+ cytotoxic T lymphocytes (CTLs). Whereas the antitumoral activity of A2V was, at least partly, CTL-dependent, perivascular T cells concurrently up-regulated the expression of the immune checkpoint ligand programmed cell death ligand 1 (PD-L1) in tumor endothelial cells. IFNγ neutralization blunted this adaptive response, and PD-1 blockade improved tumor control by A2V in different cancer models. These findings position immune cells as key effectors of antiangiogenic therapy and support the rationale for cotargeting angiogenesis and immune checkpoints in cancer therapy.

American Association for the Advancement of Science2017

Overcoming microenvironmental resistance to PD-1 blockade in genetically engineered lung cancer models

Gael Luis Boivin, Chiara Cianciaruso, Michele De Palma, Alan Nicolas Thierry Guichard, Ece Kadioglu, Ioanna Keklikoglou, Amaia Martinez Usatorre, Etienne Meylan, Sina Nassiri, Bruno Torchia, Nadine Zangger

Immune checkpoint blockade (ICB) with PD-1 or PD-L1 antibodies has been approved for the treatment of nonsmall cell lung cancer (NSCLC). However, only a minority of patients respond, and sustained remissions are rare. Both chemotherapy and antiangiogenic drugs may improve the efficacy of ICB in mouse tumor models and patients with cancer. Here, we used genetically engineered mouse models of Kras(G12D/+);p53(-/-) NSCLC, including a mismatch repair-deficient variant (Kras(G12D/+);p53(-/-);Msh2(-/-)) with higher mutational burden, and longitudinal imaging to study tumor response and resistance to combinations of ICB, antiangiogenic therapy, and chemotherapy. Antiangiogenic blockade of vascular endothelial growth factor A and angiopoietin-2 markedly slowed progression of autochthonous lung tumors, but contrary to findings in other cancer types, addition of a PD-1 or PD-L1 antibody was not beneficial and even accelerated progression of a fraction of the tumors. We found that antiangiogenic treatment facilitated tumor infiltration by PD-1(+) regulatory T cells (T-regs), which were more efficiently targeted by the PD-1 antibody than CD8(+) T cells. Both tumor-associated macrophages (TAMs) of monocyte origin, which are colony-stimulating factor 1 receptor (CSF1R) dependent, and TAMs of alveolar origin, which are sensitive to cisplatin, contributed to establish a transforming growth factor-beta-rich tumor microenvironment that supported PD-1(+) T-regs. Dual TAM targeting with a combination of a CSF1R inhibitor and cisplatin abated T-regs, redirected the PD-1 antibody to CD8(+) T cells, and improved the efficacy of antiangiogenic immunotherapy, achieving regression of most tumors.

AMER ASSOC ADVANCEMENT SCIENCE2021

An in vivo neovascularization assay for screening regulators of angiogenesis and assessing their effects on pre-existing vessels

Witold Waldemar Kilarski, Marcin Stefan Zielinski

Therapeutic regulation of tissue vascularization has appeared as an attractive approach to treat a number of human diseases. In vivo neovascularization assays that reflect physiological and pathological formation of neovessels are important in this effort. In this report we present an assay where the effects of activators and inhibitors of angiogenesis can be quantitatively and qualitatively measured. A provisional matrix composed of collagen I and fibrin was formed in a plastic cylinder and implanted onto the chick chorioallantoic membrane. A nylon mesh separated the implanted matrix from the underlying tissue to distinguish new from pre-existing vessels. Vascularization of the matrix in response to fibroblast growth factor-2 or platelet-derived growth factor-BB was scored in a double-blinded manner, or vessel density was measured using a semi-automated image analysis procedure. Thalidomide, fumagillin, U0126 and TGF beta inhibited neovessel growth while hydrocortisone exerted a negative and wortmannin a toxic effect on the pre-existing vasculature. This quantitative, inexpensive and rapid in vivo angiogenesis assay might be a valuable tool in screening and characterizing factors that influence wound or tumor induced vascularization and in assessing their effects on the normal vasculature.

Springer Netherlands2012

Overcoming microenvironmental resistance to PD-1 blockade in genetically engineered lung cancer models

AMER ASSOC ADVANCEMENT SCIENCE2021