Enhanced osteochondral regeneration with a 3D-Printed biomimetic scaffold featuring a calcified interfacial layer

The integrative regeneration of both articular cartilage and subchondral bone remains an unmet clinical need due to the difficulties of mimicking spatial complexity in native osteochondral tissues for artificial implants. Layer-by-layer fabrication strategies, such as 3D printing, have emerged as a promising technology replicating the stratified zonal architecture and varying microstructures and mechanical properties. However, the dynamic and circulating physiological environments, such as mass transportation or cell migration, usually distort the pre-confined biological properties in the layered implants, leading to undistinguished spatial variations and subsequently inefficient regenerations. This study introduced a biomimetic calcified interfacial layer into the scaffold as a compact barrier between a cartilage layer and a subchondral bone layer to facilitate osteogenic-chondrogenic repair. The calcified interfacial layer consisting of compact polycaprolactone (PCL), nano-hydroxyapatite, and tasquinimod (TA) can physically and biologically separate the cartilage layer (TA-mixed, chondrocytes-load gelatin methacrylate) from the subchondral bond layer (porous PCL). This introduction preserved the as-designed independent biological environment in each layer for both cartilage and bone regeneration, successfully inhibiting vascular invasion into the cartilage layer and preventing hyaluronic cartilage calcification owing to devascularization of TA. The improved integrative regeneration of cartilage and subchondral bone was validated through gross examination, micro-computed tomography (micro-CT), and histological and immunohistochemical analyses based on an in vivo rat model. Moreover, gene and protein expression studies identified a key role of Caveolin (CAV-1) in promoting angiogenesis through the Wnt/β-catenin pathway and indicated that TA in the calcified layer blocked angiogenesis by inhibiting CAV-1.

A Tasquinomod-loaded dopamine-modified pH sensitive hydrogel is effective at inhibiting the proliferation of KRAS mutant lung cancer cells

Hydrogels can maintain a high local drug concentration during treatments and may be useful to local targeting diseased areas. We propose a pH sensitive hydrogel consisting of poly-vinylpyrrolidone (PVP) and chitosan as a new treatment method for KRAS mutant lung cancer. Addition of dopamine improved the drug loading and release effects of this hydrogel. We demonstrate that Tasquinimod-loading of this dopamine-modified pH sensitive hydrogel is more effective than Tasquinimod alone for inhibiting the proliferation of KRAS mutant lung cancer cells. Combination of conventional drugs with hydrogels may thus provide a new treatment modality for lung cancer.

Tasquinimod efficacy and S100A9 expression in glucose-treated HREC cells

PURPOSE

Diabetic retinopathy (DR) is one of the leading causes of blindness in working-aged people. Few studies were on the relationship between S100 Calcium Binding Protein A9 (S100A9) protein and DR, and none on endothelial cells induced by tasquinimod in high glucose. Therefore, we assessed the relationship between tasquinimod and S100A9 in DR.

METHODS

DR pathogenesis was simulated using high-glucose-induced human retinal endothelial cells (HRECs) to study the mRNA expression of s100a9, thrombospondin-1 (tsp-1), hypoxia-inducible factor 1-alpha (hif1-α), intercellular adhesion molecule 1 (icam-1), and vascular endothelial growth factor (vegf) after tasquinimod treatment. The protein expression of S100A9, TSP-1, extracellular signal-regulated kinase (ERK), ICAM-1 and VEGF was also analyzed.

RESULT

A total of 28 eyes of 26 patients were included in this experiment. A significantly higher expression of S100A9 as well as enhanced proliferation and mobility was observed in the high-glucose-treated HRECs compared with that in low-glucose-treated cells. However, these were significantly inhibited when treated with high glucose with 50 μM tasquinimod. The mRNA expression of tsp-1 was increased, whereas that of hif1-α, icam-1 and vegf was decreased after tasquinimod treatment. Western blot indicated the increased TSP-1 but decreased ERK, ICAM-1 and VEGF expression after treating with tasquinimod.

CONCLUSION

High glucose promoted the expression of s100a9, S100A9 protein in DR patients and HRECs. Tasquinimod inhibited the proliferation, migration and lumen formation of HRECs under a high glucose environment. Tasquinimod might play a vital role in inhibiting angiogenesis through inducing TSP-1 and inhibiting VEGF, ICAM-1 and ERK.

Tasquinimod targets suppressive myeloid cells in the tumor microenvironment

Infiltrating myeloid derived suppressor cells and tumor-associated macrophages (TAMs) are important components of the immunosuppressive tumor microenvironment. We recently reported that tasquinimod, which binds to S100A9, impairs both infiltration and function of these cells. Here we discuss the underlying mechanisms responsible for targeting multiple suppressive populations and the modulation of the tumor microenvironment.

Tasquinimod triggers an early change in the polarization of tumor associated macrophages in the tumor microenvironment

Background

Tasquinimod (a quinoline-3-carboxyamide) is a small molecule immunotherapy with demonstrated effects on the tumor microenvironment (TME) involving immunomodulation, anti-angiogenesis and inhibition of metastasis. A target molecule of tasquinimod is the inflammatory protein S100A9 which has been shown to affect the accumulation and function of suppressive myeloid cell subsets in tumors. Given the major impact of myeloid cells to the tumor microenvironment, manipulation of this cell compartment is a desirable goal in cancer therapeutics.

Methods

To understand the consequences of tasquinimod treatment on the TME, we evaluated early treatment effects in tumor infiltrating myeloid cells. Cellular phenotypes were studied by flow cytometry while gene expression both in tumor tissue and in isolated CD11b⁺ cells or tumor cells were measured by real time-PCR. Effects on angiogenesis were monitored by changes in CD31 levels and by gene expression in tumor tissue. Effects on cytokine levels in tumor tissue and serum were determined by multiplex analysis.

Results

The MC38-C215 colon carcinoma tumors showed a substantial infiltration of primarily myeloid cells that were dominated by Ly6C^lowF4/80⁺CD206⁺ M2-polarized tumor associated macrophages (TAMs), an immuno-suppressive and pro-angiogenic cell population. Here, we show that tasquinimod treatment induces an anti-tumor effect which is subsequent to a reduction in tumor infiltrating CD206⁺ M2 macrophages and a simultaneous increase in M1 macrophages expressing MHC class II and CD86. The tasquinimod-induced changes in TAM polarization were evident within 24 h of exposure, emphasizing the ability of tasquinimod to rapidly reprogram the tumor microenvironment. This change in the tumor associated myeloid compartment preceded an increased IL12-production within the tumor and a decrease in tumor neovascularization. The switch in TAM polarization by tasquinimod was confirmed in the 4T1 breast cancer model where tasquinimod also reduce lung metastasis development.

Conclusion

Our data show that tasquinimod affects tumor infiltrating myeloid cells early after exposure, leading to a change in phenotype from pro-angiogenic and immunosuppressive M2-like TAMs to pro-inflammatory M1-like macrophages. These changes are consistent with the effects of tasquinimod seen on tumor vascularization, immune suppression and metastasis giving further insights to the anti-tumor mechanism of action of tasquinimod.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-015-0098-5) contains supplementary material, which is available to authorized users.

[Tasquinimod: How to act on microenvironment in metastatic prostate cancer]

Despite the recent introduction of new drugs, castration-resistant metastatic prostate cancer, (mCRPC) remains a poor prognosis disease, with a crucial need for new therapeutic approaches. Tasquinimod is a newly developed molecule, orally administered, currently evaluated in phase III studies. Tasquinimod targets the tumor microenvironment, focusing on the angiogenic and immune components. Its specific action on the S100A9 protein restores immunity and reduces angiogenesis. A phase II double-blind randomized study against placebo showed an improvement of more than 50% of progression free survival in the group of mCRPC patients treated with tasquinimod, as compared to the placebo group. At a dose of 1mg/day, the tolerance of tasquinimod appeared acceptable. This review presents the available preclinical and clinical results of tasquinimod, with a particular focus on the originality of its mode of action.

Assessment of the bone scan index in a randomized placebo-controlled trial of tasquinimod in men with metastatic castration-resistant prostate cancer (mCRPC)

INTRODUCTION

Drug development and clinical decision making for patients with metastatic prostate cancer (PC) have been hindered by a lack of quantitative methods of assessing changes in bony disease burden that are associated with overall survival (OS). Bone scan index (BSI), a quantitative imaging biomarker of bone tumor burden, is prognostic in men with metastatic PC. We evaluated an automated method for BSI calculation for the association between BSI over time with clinical outcomes in a randomized double-blind trial of tasquinimod (TASQ) in men with metastatic castration-resistant PC (mCRPC).

METHODS

Bone scans collected during central review from the TASQ trial were analyzed retrospectively using EXINIbone(BSI), an automated software package for BSI calculation. Associations between BSI and other prognostic biomarkers, progression-free survival, OS, and treatment were evaluated over time.

RESULTS

Of 201 men (57 TASQ and 28 placebo), 85 contributed scans at baseline and week 12 of sufficient quality. Baseline BSI correlated with prostate-specific antigen and alkaline phosphatase levels and was associated with OS in univariate (hazard ratio [HR] = 1.42, P = 0.013) and multivariate (HR = 1.64, P<0.001) analyses. BSI worsening at 12 weeks was prognostic for progression-free survival (HR = 2.14 per BSI doubling, P<0.001) and OS (HR = 1.58, P = 0.033) in multivariate analyses including baseline BSI and TASQ treatment. TASQ delayed BSI progression.

CONCLUSIONS

BSI and BSI changes over time were independently associated with OS in men with mCRPC. A delay in objective radiographic bone scan progression with TASQ is suggested; prospective evaluation of BSI progression and response criteria in phase 3 trials of men with mCRPC is warranted.

Quantitative determination of the anti-tumor agent tasquinimod in human urine by liquid chromatography-tandem mass spectrometry

Tasquinimod is an anti-tumor drug that is currently in clinical development for the treatment of solid cancers. After oral administration, tasquinimod and a number of its metabolites are excreted in the urine. The quantitative determination of tasquinimod in urine is challenging because of the required sensitivity (down to 0.1nM or 40pg/mL), the highly variable nature of this biological matrix and the presence of potentially unstable metabolites, which may convert back to the parent drug. In this article, an LC-MS/MS method is described for the determination of tasquinimod in human urine in the concentration range 0.1-200nM. Liquid-liquid extraction with n-chlorobutane was used to extract tasquinimod from 100μL human urine and to remove interfering endogenous urinary constituents. Reversed-phase liquid chromatography coupled to a triple quadrupole mass spectrometer equipped with an ESI source was used for quantification of tasquinimod in a 2.5-min run. A stable-isotope labeled internal standard was used for response normalization. The intra- and inter-day coefficients of variation (precision) as well as the bias (accuracy) of the method were below 7%. Although considerable conversion of conjugated tasquinimod metabolites back to parent drug was observed when incurred samples were stored at 37°C for a prolonged time, tasquinimod as well as its metabolites were sufficiently stable under all relevant sampling, storage and analysis conditions. The method was successfully applied to determine the urinary excretion of tasquinimod in healthy volunteers and patients with renal impairment after a 0.5-mg oral dose.