The direct oral anticoagulants rivaroxaban and dabigatran do not inhibit orthotopic growth and metastasis of human breast cancer in mice

Factor Xa‐targeting DOACs were recently found to reduce recurrentVTE efficiently in cancer patients when compared to the standard treatment withlow‐molecular‐weight heparins (LMWHs). While the anticancer effects of LMWHshave been extensively studied in preclinical cancer models, the effects of FXa‐targetingDOACs on cancer progression remain to be studied.We investigated whether the FXa‐targeting DOAC rivaroxaban and thethrombin‐targeting DOAC dabigatran etexilate (DE) affected human breast cancergrowth and metastasis in orthotopic xenograft models.Mice that were put on a custom‐made chow diet supplementedwith rivaroxaban (0.4 or 1.0 mg/g diet) or dabigatran etexilate (DE) (10 mg/g diet)showed prolonged ex vivo coagulation times (prothrombin time [PT] and activatedpartial thromboplastin time [aPTT] assay, respectively). However, rivaroxabanand DE did not inhibit MDA‐MB‐231 tumor growth and metastasis formationin lungs or livers of 7‐week‐old fully immunodeficient NOD/SCID/ƴC−/− (NSG) mice.Comparable data were obtained for rivaroxaban‐treated mice when using NOD‐SCIDmice. Rivaroxaban and DE treatment also did not significantly inhibit tumor growthand metastasis formation when using another human triple negative breast cancer(TNBC) cell line (HCC1806) in NOD‐SCID mice. The FXa and thrombin‐induced geneexpression of the downstream target CXCL8 in both cell lines, but FXa and thrombin,did not significantly stimulate migration, proliferation, or stemness in vitro.Although effectively inhibiting coagulation, the DOACs rivaroxaban andDE did not inhibit orthotopic growth and metastasis of human TNBC. It remains to beinvestigated whether DOACs exert antitumorigenic effects in other types of cancer.Toxicolog

Smchd1 haploinsufficiency exacerbates the phenotype of a transgenic FSHD1 mouse model

Functional Genomics of Muscle, Nerve and Brain Disorder

Direct oral anticoagulants do not inhibit growth and metastasis of human triple negative breast cancer in immunodeficient mice

It has been well-established that cancer results in a hypercoagulable state and an increased risk for venous thromboembolism (VTE). More recently, it has been suggested that coagulation may also affect cancer progression and metastasis. Cancer patients with VTE are currently treated with the anticoagulant low molecular weight heparins (LMWHs). Preclinical studies have shown that LMWHs can inhibit metastasis formation in several types of cancer, but beneficial effects of LMWHs on survival have not been consistently found in clinical trials. Recently, a new class of anticoagulants are available for treatment of VTE, the so-called direct oral anticoagulant (DOACs), which include dabigatran and rivaroxaban, a direct thrombin and FXa inhibitor, respectively. However, the effects of DOACs on cancer are currently under studied.Toxicolog

Integrin regulation by tissue factor promotes cancer stemness and metastatic dissemination in breast cancer

Tissue Factor (TF) is the initiator of blood coagulation but also functions as a signal transduction receptor. TF expression in breast cancer is associated with higher tumor grade, metastasis and poor survival. The role of TF signaling on the early phases of metastasis has never been addressed. Here, we show an association between TF expression and metastasis as well as cancer stemness in 574 breast cancer patients. In preclinical models, blockade of TF signaling inhibited metastasis tenfold independent of primary tumor growth. TF blockade caused a reduction in epithelial-to-mesenchymal-transition, cancer stemness and expression of the pro-metastatic markers Slug and SOX9 in several breast cancer cell lines and in ex vivo cultured tumor cells. Mechanistically, TF forms a complex with beta 1-integrin leading to inactivation of beta 1-integrin. Inhibition of TF signaling induces a shift in TF-binding from alpha 3 beta 1-integrin to alpha 6 beta 4 and dictates FAK recruitment, leading to reduced epithelial-to-mesenchymal-transition and tumor cell differentiation. In conclusion, TF signaling inhibition leads to reduced pro-metastatic transcriptional programs, and a subsequent integrin beta 1 and beta 4-dependent reduction in metastasic dissemination.Thrombosis and Hemostasi

Mutations in DNMT3B Modify Epigenetic Repression of the D4Z4 Repeat and the Penetrance of Facioscapulohumeral Dystrophy

Functional Genomics of Muscle, Nerve and Brain Disorder

Tumor-expressed factor VII is associated with survival and regulates tumor progression in breast cancer

Cancer enhances the risk of venous thromboembolism, but a hypercoagulant microenvironment also promotes cancer progression. Although anticoagulants have been suggested as a potential anticancer treatment, clinical studies on the effect of such modalities on cancer progression have not yet been successful for unknown reasons. In normal physiology, complex formation between the subendothelial-expressed tissue factor (TF) and the blood-borne liver-derived factor VII (FVII) results in induction of the extrinsic coagulation cascade and intracellular signaling via protease-activated receptors (PARs). In cancer, TF is overexpressed and linked to poor prognosis. Here, we report that increased levels of FVII are also observed in breast cancer specimens and are associated with tumor progression and metastasis to the liver. In breast cancer cell lines, tumor-expressed FVII drives changes reminiscent of epithelial-to-mesenchymal transition (EMT), tumor cell invasion, and expression of the prometastatic genes, SNAI2 and SOX9. In vivo, tumorexpressed FVII enhanced tumor growth and liver metastasis. Surprisingly, liver-derived FVII appeared to inhibit metastasis. Finally, tumor-expressed FVII-induced prometastatic gene expression independent of TF but required a functional endothelial protein C receptor, whereas recombinant activated FVII acting via the canonical TF:PAR2 pathway inhibited prometastatic gene expression. Here, we propose that tumor-expressed FVII and liverderived FVII have opposing effects on EMT and metastasis.Surgical oncolog