High-affinity Cu(I) chelator PSP-2 as potential anti-angiogenic agent

Abstract

Copper is an essential trace metal that has been implicated in angiogenesis, the formation of new blood vessels. As tumor growth relies on establishing a functional capillary network for blood supply, copper chelation therapy may hold promise as an anti-cancer strategy by suppressing angiogenesis. To test the anti-angiogenic effect of PSP-2, a recently developed high affinity Cu(I) chelator with low zeptomolar dissociation constant, we utilized the endothelial cancer cell line EAhy926 and assessed changes in cell migration, proliferation, and tube formation in Matrigel. In addition, sprouting was assessed by the chicken and sheep aortic ring assay, and vascular pattern formation was studied in the chorioallantoic membrane of chicken embryos (CAM assay). While incubation with PSP-2 resulted in selective depletion of cellular copper levels, cell migration was not affected and the proliferating activity was even slightly increased. Moreover, the endothelial tube formation assay revealed significant morphological changes in the presence of PSP-2, with thicker tubular walls and an overall decreased meshes area. Similarly, the aortic ring assay and CAM assay showed that PSP-2 evokes significantly longer sprouts with smaller angles at branching points. Altogether, PSP-2 exhibits significant bioactivity at concentrations as low as 5 μM, rendering it a promising anti-angiogenic agent. As EAhy926 cells exhibit both endothelial and tumorigenic properties, the anti-angiogenic effect of PSP-2 might potentially translate also into anti-cancer activity.

Identification of cuproptosis‐related lncRNAs for prognosis and immunotherapy in glioma

“…We reasonably speculated that cuproptosis, a recently defined form of cell death, is correlated with glioma prognosis. Although the mechanisms underlying cuproptosis have not been determined, increasing evidence has indicated the significant role played by copper in tumour development and immunity: An increasing number of studies have shown that copper‐induced tumour cell death was associated with mitochondrial dysfunction, proteasome inhibition and antiangiogenesis 37–40 . Furthermore, intratumoral copper can regulate key signalling pathways that mediate PD‐L1‐driven cancer immune evasion 41 .…”

“…Although the mechanisms underlying cuproptosis have not been determined, increasing evidence has indicated the significant role played by copper in tumour development and immunity: An increasing number of studies have shown that copper-induced tumour cell death was associated with mitochondrial dysfunction, proteasome inhibition and antiangiogenesis. [37][38][39][40]…”

Microvascular Experimentation in the Chick Chorioallantoic Membrane as a Model for Screening Angiogenic Agents including from Gene-Modified Cells

“…For automated methods, many software packages exist which can be adapted to identify tubules, vessel branch points and network junctions. Such software packages include: Angiotool [ 221 ], AngioQuant [ 60 , 73 , 137 ], Wimasis [ 87 , 101 ], HetCAM [ 222 ], Photoshop CS4 [ 223 ] and Synedra view [ 224 ]. Image analysis software such as Image J can be used for both manual and semi-automated quantification methods.…”

High-Affinity Cu(I)-Chelator with Potential Anti-Tumorigenic Action—A Proof-of-Principle Experimental Study of Human H460 Tumors in the CAM Assay

“…Previously, our research group reported on the anti-angiogenic effects of the novel membrane-permeant high-affinity Cu(I) chelator PSP-2 [ 33 ], which binds Cu(I) with low zeptomolar affinity. We demonstrated that PSP-2 adversely affects tube formation of tumorigenic endothelial cells EAhy926 in vitro, impaired normal sprouting in the aortic ring assay, and resulted in suppressed branching, in favor of long, parallel arranged vessels in the chorioallantoic membrane of the chicken embryo (CAM assay) in ovo [ 33 ]. In the current study, we directly explored the potential anti-tumorigenic action of PSP-2.…”

“…Tetrathiomolybdate was also combined with radiotherapy and proved effective in a mouse Lewis lung metastatic tumor model [ 31 ]. Recently, our research team evaluated a new high-affinity Cu(I) chelator, PSP-2 [ 32 ], for its potential anti-angiogenic activity in vitro and in ovo, i.e., in the chorioallantoic membrane assay of the chicken embryo (CAM assay) [ 33 ]. We were able to show a significant reduction in angiogenic activity when PSP-2 was applied.…”