Targeting extracellular matrix through phytochemicals: a promising approach of multi-step actions on the treatment and prevention of cancer

Enhanced Tumor Site Accumulation and Therapeutic Efficacy of Extracellular Matrix-Drug Conjugates Targeting Tumor Cells

The extracellular matrix (ECM) engages in regulatory interactions with cell surface receptors through its constituent proteins and polysaccharides. Therefore, nano-sized extracellular matrix conjugated with doxorubicin (DOX) is utilized to produce extracellular matrix-drug conjugates (ECM-DOX) tailored for targeted delivery to cancer cells. The ECM-DOX nanoparticles exhibit rod-like morphology, boasting a commendable drug loading capacity of 4.58%, coupled with acid-sensitive drug release characteristics. Notably, ECM-DOX nanoparticles enhance the uptake by tumor cells and possess the ability to penetrate endothelial cells and infiltrate tumor multicellular spheroids. Mechanistic insights reveal that the internalization of ECM-DOX nanoparticle is facilitated through clathrin-mediated endocytosis and macropinocytosis, intricately involving hyaluronic acid receptors and integrins. Pharmacokinetic assessments unveil a prolonged blood half-life of ECM-DOX nanoparticles at 3.65 h, a substantial improvement over the 1.09 h observed for free DOX. A sustained accumulation effect of ECM-DOX nanoparticles at tumor sites, with drug levels in tumor tissues surpassing those of free DOX by several-fold. The profound therapeutic impact of ECM-DOX nanoparticles is evident in their notable inhibition of tumor growth, extension of median survival time in animals, and significant reduction in DOX-induced cardiotoxicity. The ECM platform emerges as a promising carrier for avant-garde nanomedicines in the realm of cancer treatment.

CXCR7 promotes pulmonary vascular remodeling via targeting p38/MMP2 pathway in pulmonary arterial hypertension

Background

A hallmark feature of pulmonary arterial hypertension (PAH) is the excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) in the pulmonary arteries. The exact role of C-X-C motif chemokine ligand 12 (CXCL12)/chemokine receptor type 7 (CXCR7) in the PASMCs remains unknown. This study was conducted to investigate CXCR7's role in p38/MMP2 pathway and its effect on PASMCs.

Methods

In this study, we examined the expression profile of CXCL12/CXCR7 in both hypoxic rats and PASMCs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to measure the level of proliferation in PASMCs. Enzyme-linked immunosorbent assay (ELISA) and western blotting assays were applied to investigate the protein expression of the related molecules.

Results

We found that a high level of CXCR7 was correlated with remodeled pulmonary arterioles in hypoxic rats. Moreover, CXCR7 protein levels were significantly increased by the induction of CXCL12, indicating that the CXCL12-CXCR7 axis participates in PAH. During hypoxia-PAH, CXCR7 inhibition reduces right ventricular systolic pressure (RVSP), the Fulton index, and pulmonary arteriosclerosis remodeling. Further study indicated inhibition CXCR7 reduced PASMCs by downregulating MMP2, via p38 MAPK pathway. It was additionally found that CXCL12/CXCR7 stimulated the phosphorylation of the p38 MAPK pathway, which was a contributing factor to the decrease in MMP2 expression following preconditioning with SB203580, which inhibited p38 MAPK.

Conclusions

In summary, these findings suggest that CXCL12/CXCR7 plays a critical role in PAH, the therapy of which can be developed further by targeting its potential targets.

Improving the Efficacy of Common Cancer Treatments via Targeted Therapeutics towards the Tumour and Its Microenvironment

Cancer is defined as the uncontrolled proliferation of heterogeneous cell cultures in the body that develop abnormalities and mutations, leading to their resistance to many forms of treatment. Left untreated, these abnormal cell growths can lead to detrimental and even fatal complications for patients. Radiation therapy is involved in around 50% of cancer treatment workflows; however, it presents significant recurrence rates and normal tissue toxicity, given the inevitable deposition of the dose to the surrounding healthy tissue. Chemotherapy is another treatment modality with excessive normal tissue toxicity that significantly affects patients' quality of life. To improve the therapeutic efficacy of radiotherapy and chemotherapy, multiple conjunctive modalities have been proposed, which include the targeting of components of the tumour microenvironment inhibiting tumour spread and anti-therapeutic pathways, increasing the oxygen content within the tumour to revert the hypoxic nature of the malignancy, improving the local dose deposition with metal nanoparticles, and the restriction of the cell cycle within radiosensitive phases. The tumour microenvironment is largely responsible for inhibiting nanoparticle capture within the tumour itself and improving resistance to various forms of cancer therapy. In this review, we discuss the current literature surrounding the administration of molecular and nanoparticle therapeutics, their pharmacokinetics, and contrasting mechanisms of action. The review aims to demonstrate the advancements in the field of conjugated nanomaterials and radiotherapeutics targeting, inhibiting, or bypassing the tumour microenvironment to promote further research that can improve treatment outcomes and toxicity rates.

Matrix stiffness affects tumor-associated macrophage functional polarization and its potential in tumor therapy

The extracellular matrix (ECM) plays critical roles in cytoskeletal support, biomechanical transduction and biochemical signal transformation. Tumor-associated macrophage (TAM) function is regulated by matrix stiffness in solid tumors and is often associated with poor prognosis. ECM stiffness-induced mechanical cues can activate cell membrane mechanoreceptors and corresponding mechanotransducers in the cytoplasm, modulating the phenotype of TAMs. Currently, tuning TAM polarization through matrix stiffness-induced mechanical stimulation has received increasing attention, whereas its effect on TAM fate has rarely been summarized. A better understanding of the relationship between matrix stiffness and macrophage function will contribute to the development of new strategies for cancer therapy. In this review, we first introduced the overall relationship between macrophage polarization and matrix stiffness, analyzed the changes in mechanoreceptors and mechanotransducers mediated by matrix stiffness on macrophage function and tumor progression, and finally summarized the effects of targeting ECM stiffness on tumor prognosis to provide insight into this new field.