Serum-derived factors of breast cancer patients with brain metastases alter permeability of a human blood–brain barrier model

Abstract

Background: The most threatening metastases in breast cancer are brain metastases, which correlate with a very poor overall survival, but also a limited quality of life. A key event for the metastatic progression of breast cancer into the brain is the migration of cancer cells across the blood-brain barrier (BBB). Methods: We adapted and validated the CD34 + cells-derived human in vitro BBB model (brain-like endothelial cells, BLECs) to analyse the effects of patient serum on BBB properties. We collected serum samples from healthy donors, breast cancer patients with primary cancer, and breast cancer patients with, bone, visceral or cerebral metastases. We analysed cytokine levels in these sera utilizing immunoassays and correlated them with clinical data. We used paracellular permeability measurements, immunofluorescence staining, Western blot and mRNA analysis to examine the effects of patient sera on the properties of BBB in vitro. Results: The BLECs cultured together with brain pericytes in transwells developed a tight monolayer with a correct localization of claudin-5 at the tight junctions (TJ). Several BBB marker proteins such as the TJ proteins claudin-5 and occludin, the glucose transporter GLUT-1 or the efflux pumps PG-P and BCRP were upregulated in these cultures. This was accompanied by a reduced paracellular permeability for fluorescein (400 Da). We then used this model for the treatment with the patient sera. Only the sera of breast cancer patients with cerebral metastases had significantly increased levels of the cytokines fractalkine (CX3CL1) and BCA-1 (CXCL13). The increased levels of fractalkine were associated with the estrogen/progesterone receptor status of the tumour. The treatment of BLECs with these sera selectively increased the expression of CXCL13 and TJ protein occludin. In addition, the permeability of fluorescein was increased after serum treatment. Conclusion: We demonstrate that the CD34 + cell-derived human in vitro BBB model can be used as a tool to study the molecular mechanisms underlying cerebrovascular pathologies. We showed that serum from patients with

Benzoinum exerts NVU protective effect by inhibiting cell apoptosis in cerebral ischemia rats

“…The tight junctions are highly developed and played a key role in the establishment of BBB [32,33]. Claudin 5 is the has been considered the important adhesion molecule of tight junctions involved in BBB in present study [34][35][36]. In our study, the results suggested that benzoinum could reduce the BBB injury by increasing in Claudin 5.…”

Deletion of Protocadherin Gamma C3 Induces Phenotypic and Functional Changes in Brain Microvascular Endothelial Cells In Vitro

“…Wild type (WT) and PcdhgC3 knockout (KO) cerebEND cells were grown on gelatin-coated transwells (pore size 0.4 µm, Corning) for 6 days. The permeability assay was performed as previously described ( Curtaz et al, 2020 ) using 1 µM fluorescein (376 kDa, Sigma-Aldrich) for 1 h with aliquots taken from the basolateral compartment every 20 min. A parallel assay with cell-free transwells was used to calculate the endothelial permeability coefficient (Pe).…”

CXCL13/CXCR5 Interaction Facilitates VCAM-1-Dependent Migration in Human Osteosarcoma

“…Although CXCL13-regulated cancer cell migration and metastasis has been reported in some cancers [ 16 ], the effect of CXCL13 in the motility of osteosarcoma cells remains uncertain. Numerous studies have shown that human physiological concentrations of CXCL13 are significantly increased in cancer patients compared with healthy controls [ 25 ]. Other cancer researchers have used treatment concentrations of CXCL13 in the range of 50–100 ng/mL [ 26 , 27 ], so the concentrations used in our study are physiologically relevant.…”