Tissue factor: a critical role in inflammation and cancer

Exposure-safety and exposure-efficacy analyses for tisotumab vedotin for patients with locally advanced or metastatic solid tumors

The antibody-drug conjugate (ADC) tisotumab vedotin (TV) received accelerated approval from the US Food and Drug Administration for treatment of adults with recurrent or metastatic cervical cancer (r/mCC) with disease progression on or after chemotherapy. A population pharmacokinetic (PK) model, developed using dosing data from four clinical TV studies, was used to estimate individual exposure and explore safety and efficacy exposure-response (ER) relationships. Because PK analysis showed no appreciable accumulation of TV and monomethyl auristatin E (MMAE) with repeated dosing, cycle 1 exposure metrics and predicted average concentrations from time zero until end of the cycle in which an event occurred (CavgLast ) were used for ER analyses. The probability of achieving objective response increased significantly as the ADC cycle 1 maximum serum concentration (Cmax ) increased. The probability of treatment-related adverse events (AEs) leading to dose modification increased significantly as ADC cycle 1 area under the concentration-time curve (AUC) increased. Number of grade 2+ ocular AEs increased significantly as ADC cycle 1 AUC, Cmax , and ADC CavgLast increased. MMAE cycle 1 AUC predicted risk of serious treatment-related AEs. The relationship between ADC exposure and efficacy end points suggests ADC treatment was associated with clinically meaningful response across the observed exposures; greater exposure was associated with increased efficacy. The relationship between ADC and MMAE exposure and safety end points suggests increased exposure was associated with increased AE risk. These results align with clinical findings showing TV 2 mg/kg (≤200 mg for patients ≥100 kg) every 3 weeks is efficacious and tolerable for patients with r/mCC.

Tisotumab Vedotin in Previously Treated Recurrent or Metastatic Cervical Cancer

PURPOSE

Tissue factor (TF) is a potential target in cervical cancer, as it is frequently highly expressed and associated with poor prognosis. Tisotumab vedotin, a first-in-class investigational antibody-drug conjugate targeting TF, has demonstrated encouraging activity in solid tumors. Here we report data from the cervical cancer cohort of innovaTV 201 phase I/II study (NCT02001623).

PATIENTS AND METHODS

Patients with recurrent or metastatic cervical cancer received tisotumab vedotin 2.0 mg/kg every 3 weeks until progressive disease, unacceptable toxicity, or consent withdrawal. The primary objective was safety and tolerability. Secondary objectives included antitumor activity.

RESULTS

Of the 55 patients, 51% had received ≥2 prior lines of treatment in the recurrent or metastatic setting; 67% had prior bevacizumab + doublet chemotherapy. Fifty-one percent of patients had squamous cell carcinoma. The most common grade 3/4 treatment-emergent adverse events (AEs) were anemia (11%), fatigue (9%), and vomiting (7%). No grade 5 treatment-related AEs occurred. Investigator-assessed confirmed objective response rate (ORR) was 24% [95% confidence interval (CI): 13%-37%]. Median duration of response (DOR) was 4.2 months (range: 1.0+-9.7); four patients responded for >8 months. The 6-month progression-free survival (PFS) rate was 29% (95% CI: 17%-43%). Independent review outcomes were comparable, with confirmed ORR of 22% (95% CI: 12%-35%), median DOR of 6.0 months (range: 1.0+-9.7), and 6-month PFS rate of 40% (95% CI: 24%-55%). Tissue factor expression was confirmed in most patients; no significant association with response was observed.

CONCLUSIONS

Tisotumab vedotin demonstrated a manageable safety profile and encouraging antitumor activity in patients with previously treated recurrent or metastatic cervical cancer.

Thrombogenic Risk Induced by Intravascular Mesenchymal Stem Cell Therapy: Current Status and Future Perspectives

Mesenchymal stem cells (MSCs) are currently studied and used in numerous clinical trials. Nevertheless, some concerns have been raised regarding the safety of these infusions and the thrombogenic risk they induce. MSCs express procoagulant activity (PCA) linked to the expression of tissue factor (TF) that, when in contact with blood, initiates coagulation. Some even describe a dual activation of both the coagulation and the complement pathway, called Instant Blood-Mediated Inflammatory Reaction (IBMIR), explaining the disappointing results and low engraftment rates in clinical trials. However, nowadays, different approaches to modulate the PCA of MSCs and thus control the thrombogenic risk after cell infusion are being studied. This review summarizes both in vitro and in vivo studies on the PCA of MSC of various origins. It further emphasizes the crucial role of TF linked to the PCA of MSCs. Furthermore, optimization of MSC therapy protocols using different methods to control the PCA of MSCs are described.

Biomarkers of endothelial activation and thrombosis in tunnel construction workers exposed to airborne contaminants

OBJECTIVES

The aims were to study biomarkers of systemic inflammation, platelet/endothelial activation and thrombosis in tunnel construction workers (TCW).

METHODS

Biomarkers and blood fatty acids were measured in blood of 90 TCW and 50 referents before (baseline) and towards the end (follow-up) of a 12 days work period. They had been absent from work for 9 days at baseline. Air samples were collected by personal sampling.

RESULTS

Personal thoracic air samples showed geometric mean (GM) particulate matter and α-quartz concentrations of 604 and 74 µg/m³, respectively. The arithmetic mean (AM) concentration of elemental carbon was 51 µg/m³. The GM (and 95% confidence interval) concentration of the pro-inflammatory cytokine TNF-α decreased from 2.2 (2.0-2.4) at baseline to 2.0 pg/mL (1.8-2.2) (p = 0.02) at follow-up among the TCW. Also the platelet activation biomarkers P-selectin and CD40L decreased significantly [25.4 (24.1-26.6) to 24.4 (22.9-26.0)] ng/mL, p = 0.04 and 125 (114-137) to 105 (96-115) pg/mL, p < 0.001, respectively. ICAM-1 concentrations increased from 249 (238-260) to 254 (243-266) ng/mL (p = 0.02). No significant alterations were observed among the referents when assessed by paired sample t test. Unbeneficial alterations in blood fatty acid composition were observed between baseline and follow-up, mainly among referents.

CONCLUSIONS

TCW had slightly reduced systemic inflammation and platelet activation although highly exposed to particulate matter, α-quarz and diesel exhaust, which might be due to increased physical activity during the exposure period. The slightly increased ICAM-1 may indicate monocyte recruitment to the lungs. The diet was substantially altered towards a less beneficial fatty acid profile.

Changes in the Laboratory Data for Cancer Patients Treated with Korean-medicine-based Inpatient Care

OBJECTIVES

The study aimed to determine changes in laboratory data for cancer patients receiving Korean medicine (KM) care, with a focus on patients' functional status, cancer-coagulation factors and cancer immunity.

METHODS

We conducted an observational study of various cancer patients in all stages admitted to the East-West Cancer Center (EWCC), Dunsan Korean Hospital of Daejeon University, from Mar. 2011 to Aug. 2011. All patients were under the center's multi-modality Korean-medicine-based inpatient cancer care program. The hospitalization stay at EWCC ranged from 9 to 34 days. A total of 80 patients were followed in their routine hematologic laboratory screenings performed before and after hospitalization. Patients were divided into three groups depending on the status of their treatment: prevention of recurrence and metastasis group, Korean medicine (KM) treatment only group, and combination of conventional and KM treatment group. The lab reports included natural killer (NK) cell count (CD16 + CD56), fibrinogen, white blood cell (WBC), lymphocytes, monocytes, neutrophil, red blood cell (RBC), hemoglobin, platelet, Erythrocyte Sedimentation Rate (ESR), and Eastern Cooperative Oncology Group (ECOG) performance status.

RESULTS

With a Focus on patients' functional status, cancer-coagulation factors and cancer immunity, emphasis was placed on the NK cell count, fibrinogen count, and ECOG scores. Data generally revealed decreased fibrinogen count, fluctuating NK cell count and decreased ECOG, meaning improved performance status in all groups. The KM treatment only group showed the largest decrease in mean fibrinogen count and the largest increase in mean NK cell count. However, the group's ECOG score showed the smallest decrease, which may be due to the concentration of late-cancer-stage patients in that particular group.

CONCLUSIONS

Multi-modality KM inpatient care may have positive effect on lowering the cancer coagulation factor fibrinogen, but its correlation with the change in the NK cell count is not clear.

Overexpression of CCN3 inhibits inflammation and progression of atherosclerosis in apolipoprotein E-deficient mice

Background

Cysteine-rich 61/connective tissue growth factor/nephroblastoma overexpressed (CCN) 3 has been recently reported to play a role in regulating inflammation of vascular endothelial cells. However, the role of CCN3 in atherosclerosis, which is characterized by vascular inflammation, remains unclear.

Hypothesis and Objectives

Overexpression of CCN3 may relieve the inflammation response in and inhibit the progress of atherosclerosis. We aimed to explore the potential roles of CCN3 in inflammation in atherosclerosis.

Strategy and Main Results

In in vitro studies using cultured human aortic endothelial cells and human umbilical vein endothelial cells, CCN3 mRNA and protein expression significantly decreased in response to tumor necrosis factor-α and interleukin-1β treatments (p<0.05), when analyzed by quantitative real-time polymerase chain reaction and Western blot. Using a mouse model of atherosclerosis, the mRNA and protein levels of CCN3 decreased by 72.2% (p = 0.041) and 86.4% (p = 0.036), respectively, compared with levels in wild-type control mice, respectively. Overexpression of CCN3 by adenovirus-mediated gene overexpression decreased low-density lipoprotein cholesterol by 48.9% (p = 0.017), total cholesterol by 58.9% (p = 0.031), and triglycerides by 56.8% (p = 0.022), and it increased high-density lipoprotein cholesterol level by 2.16-fold (p = 0.039), compared with control groups. Additionally, a reduced plaque area and increased fibrous cap were observed (p<0.05). Furthermore, CCN3 overexpression decreased cell adhesion molecule-1 mRNA expression by 84.7% (p = 0.007) and intercellular adhesion molecule-1 mRNA expression by 61.2% (p = 0.044). Inflammatory factors, including matrix metalloproteinases, cyclooxygenase 2, and tissue factor also significantly (p<0.05) decreased with CCN3 overexpression in the atherosclerotic mouse model. Additionally, CCN1 and CCN2, which have been reported to be highly expressed in aortic atherosclerotic plaques, were significantly downregulated (p<0.05) by CCN3 overexpression.

Conclusion

CCN3 overexpression is associated with control of inflammatory processes and reversion of dyslipidemia in the process of atherosclerosis, which implies that CCN3 may be a promising target in the treatment of atherosclerosis.

Inhibitory Effect of an Urotensin II Receptor Antagonist on Proinflammatory Activation Induced by Urotensin II in Human Vascular Endothelial Cells

In this study, we investigated the effects of a selective urotensin II (UII) receptor antagonist, SB-657510, on the inflammatory response induced by UII in human umbilical vein endothelial cells (EA.hy926) and human monocytes (U937). UII induced inflammatory activation of endothelial cells through expression of proinflammatory cytokines (IL-1β and IL-6), adhesion molecules (VCAM-1), and tissue factor (TF), which facilitates the adhesion of monocytes to EA.hy926 cells. Treatment with SB-657510 significantly inhibited UII-induced expression of IL-1β, IL-6, and VCAM-1 in EA.hy926 cells. Further, SB-657510 dramatically blocked the UII-induced increase in adhesion between U937 and EA.hy926 cells. In addition, SB-657510 remarkably reduced UII-induced expression of TF in EA.hy926 cells. Taken together, our results demonstrate that the UII antagonist SB-657510 decreases the progression of inflammation induced by UII in endothelial cells.

Knockdown of mTOR by lentivirus‑mediated RNA interference suppresses atherosclerosis and stabilizes plaques via a decrease of macrophages by autophagy in apolipoprotein E‑deficient mice

Atherosclerotic plaque destabilization and rupture leads to acute coronary syndromes which cause serious damage to human health worldwide. However, there is currently a lack of efficient therapeutic methods. Mammalian target of rapamycin (mTOR) has been suggested to be involved in the development of atherosclerotic plaques and serves as a therapeutic target. The present study was performed to determine whether RNA interference (RNAi) of mTOR in vivo by LV‑mediated small hairpin RNA (shRNA) was capable of inhibiting the progression of atherosclerotic plaques. LV‑mediated shRNA against mTOR (LV‑shmTOR) was designed and obtained. Male apolipoprotein E‑deficient mice were fed a high‑fat diet and a constrictive collar was placed around the right carotid arteries of these mice to induce plaque formation. Eight weeks after surgery, mice were randomly divided into the mTOR RNA interference (LV‑shmTOR) group, receiving treatment with LV‑mTOR‑shRNA; the LV‑shCON group, receiving treatment with LV‑non‑specific‑shRNA; and the control group, receiving treatment with phosphate‑buffered saline. Following transfection, the mice were sacrificed to evaluate the effects of mTOR expression silencing on atherosclerosis. Transfection of LV‑mTOR‑shRNA markedly inhibited the mRNA and protein expression levels. Knockdown of mTOR ameliorated dysregulated blood lipid metabolism and stabilized aortic atherosclerotic plaques by decreasing the plaque area and increasing the fibrous cap and cap‑to‑core ratio. Furthermore, macrophages were decreased by silencing mTOR in atherosclerotic plaques. In addition, western blot analysis revealed that the knockdown of mTOR increased autophagy‑related protein 13 (Atg13) dephosphorylation and light chain 3‑I/light chain 3‑II (LC3‑I/LC3‑II) ratios, both of which were associated with a high activity of autophagy, suggesting an increase of autophagy in atherosclerotic plaques. Moreover, genes including matrix metalloproteinase 2, monocyte chemoattractant protein 1 and tissue factor, which promote plaque instability, were downregulated by silencing mTOR. These results demonstrate that LV‑mediated mTOR silencing by RNAi treatment induces macrophage autophagy and is a potential strategy for the treatment of atherosclerotic plaques.

Sphingomyelin synthase 2 over-expression induces expression of aortic inflammatory biomarkers and decreases circulating EPCs in ApoE KO mice

AIMS

This study sought to assess the effect of sphingomyelin synthase 2 (SMS2) over-expression on plaque component and endothelial dysfunction in atherosclerosis.

MAIN METHODS

We generated recombinant adenovirus vectors containing human SMS2 cDNA (AdV-SMS2) or control gene GFP cDNA (AdV-GFP). Both AdVs were injected (i.v.) into ApoE KO mice to establish SMS2 over-expressing and control mice models, respectively. The mice were fed a high fat diet for 30 days. We then examined their plasma lipid levels, expression levels of aortic inflammatory biomarkers critical for the plaque's stability, and numbers of peripheral endothelial progenitor cells (EPC).

KEY FINDINGS

Compared with the control mice, SMS2 over-expression had significantly (1) increased aortic matrix metalloproteinase-2 (MMP-2), monocyte chemoattractant protein-1 (MCP-1), tissue factor (TF) and cyclooxygenase-2 (COX-2) mRNA levels (1.9-fold, 2.2-fold, 2.6-fold and 3.2-fold, respectively, P<0.01) and protein levels (2.2-fold, 1.9-fold, 1.9-fold and 2.1-fold, respectively, P<0.01); (2) increased MMP-2, COX-2 in situ expression in aortic root (2.6-fold and 2.3-fold, respectively, P<0.01); (3) decreased aortic COX-1 mRNA levels (65%, P<0.01) and protein levels (64%, P<0.01); and (4) decreased CD34/KDR-positive cells (33%, P<0.01), circulating angiogenic cells (CACs) (50%, P<0.05), and colony forming units (CFUs) (40%, P<0.05) in circulation.

SIGNIFICANCE

SMS2 over-expression was probably associated with increased expression of aortic inflammatory biomarkers, as well as decreased numbers of CD34/KDR-positive cells, CACs and CFUs in circulation. Therefore, SMS2 over-expression might correlate with endothelial dysfunction and aggravate atherosclerotic plaque instability in ApoE KO mice.

A new Factor Xa inhibitor from Amblyomma cajennense with a unique domain composition

Bioactive compounds of great interest are found in the saliva of hematophagous organisms. While exploring a cDNA library derived from the salivary glands of the tick Amblyomma cajennense, a transcript that codes for a protein with unique structure (containing an N-terminal Kunitz-type domain and a C-terminus with no homology to any annotated sequences) was found. The recombinant mature form of this protein ( approximately 13.5kDa) was produced in Escherichia coli BL21 (DE3), and it was able to inhibit Factor Xa (FXa) and extend global blood clotting times in vitro and ex vivo. Static and dynamic predictions of its tertiary structure indicate regions that may be related to its FXa inhibitor function.