[64Cu]Cu-ATSM: an emerging theranostic agent for cancer and neuroinflammation

Bifunctional Copper Chelators Capable of Reducing Aβ Aggregation and Aβ-Induced Oxidative Stress

Five bifunctional copper chelating agents, Alz-(1-5), designed to prevent beta-amyloid (Aβ) aggregation, were synthesized, and the leader compound (Alz-5) was chosen. Alz-5 acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity. Reactive oxygen species measurements provided by the Pt-nanoelectrode technique in single Aβ42-affected human neuroblastoma SH-SY5Y cells revealed significant antioxidant activity of Alz-5. AFM data obtained on Aβ42 fibrils clearly indicate the antiaggregating property of Alz-5. To gain insights into the changes in the physiomechanical properties of Aβ42-affected cells, as well as in order to evaluate the antiaggregating ability of Alz-5, Young's modulus mapping on living SH-SY5Y cells affected consequently by Aβ42 and Alz-5 was conducted, and the ability of Alz-5 to decrease cell rigidity induced by Aβ42 was indisputably proven. Low cell toxicity and antioxidating properties, in conjunction with AFM and SICM-based biophysical provided on Aβ42-affected SH-SY5Y cells, support Alz-5 as a potential inhibitor of Aβ aggregation.

Unveiling the promising anticancer effect of copper-based compounds: a comprehensive review

Copper is a necessary micronutrient for maintaining the well-being of the human body. The biological activity of organic ligands, especially their anticancer activity, is often enhanced when they coordinate with copper(I) and (II) ions. Copper and its compounds are capable of inducing tumor cell death through various mechanisms of action, including activation of apoptosis signaling pathways by reactive oxygen species (ROS), inhibition of angiogenesis, induction of cuproptosis, and paraptosis. Some of the copper complexes are currently being evaluated in clinical trials for their ability to map tumor hypoxia in various cancers, including locally advanced rectal cancer and bulky tumors. Several studies have shown that copper nanoparticles can be used as effective agents in chemodynamic therapy, phototherapy, hyperthermia, and immunotherapy. Despite the promising anticancer activity of copper-based compounds, their use in clinical trials is subject to certain limitations. Elevated copper concentrations may promote tumor growth, angiogenesis, and metastasis by affecting cellular processes.

A Luciferase Reporter Assay to Detect Cellular Hypoxia In Vitro

Hypoxia is a hallmark of ischemic cardiovascular diseases and solid malignant tumors. Cellular hypoxia induces numerous physiological and pathological processes, including hematopoiesis, angiogenesis, metabolic changes, cell growth, and apoptosis. Hypoxia-inducible factor-1 (HIF-1) binds to hypoxia response elements (HREs) to selectively induce the expression of various genes in response to hypoxia. Therefore, HREs have been used to develop hypoxia-targeted gene therapy.More than 70 pairs of HREs and hypoxia-inducible genes have been identified. The hypoxia-induced gene expression levels vary among HRE sequences depending on the number of HRE copies and oxygen levels. Most known HREs have not yet been thoroughly studied. Recent studies have revealed that the HRE-mediated effects of hypoxia are cell line-dependent. Herein we describe an in vitro method to investigate gene activation levels and characteristics based on varying the copy number of HREs in response to cellular hypoxia. We explain how to clone HREs into luciferase reporter constructs in the sense, antisense, and dual directions to measure luciferase expression for functional analyses.

Assessment of hypoxia and oxidative-related changes in a lung-derived brain metastasis model by [64Cu][Cu(ATSM)] PET and proteomic studies

BACKGROUND

Brain metastases (BM) are the most frequent malignant brain tumors. The aim of this study was to characterize the tumor microenvironment (TME) of BM and particularly hypoxia and redox state, known to play a role in tumor growth and treatment resistance with multimodal PET and MRI imaging, immunohistochemical and proteomic approaches in a human lung cancer (H2030-BrM3)-derived BM model in rats.

RESULTS

First, in vitro studies confirmed that H2030-BrM3 cells respond to hypoxia with increasing expression of HIF-1, HIF-2 and their target genes. Proteomic analyses revealed, among expression changes, proteins associated with metabolism, oxidative stress, metal response and hypoxia signaling in particular in cortical BM. [64Cu][Cu(ATSM)] PET revealed a significant uptake by cortical BM (p < 0.01), while no uptake is observed in striatal BM 23 days after tumor implantation. Pimonidazole, HIF-1α, HIF-2α, CA-IX as well as GFAP, CTR1 and DMT1 immunostainings are positive in both BM.

CONCLUSION

Overall, [64Cu][Cu(ATSM)] imaging and proteomic results showed the presence of hypoxia and protein expression changes linked to hypoxia and oxidative stress in BM, which are more pronounced in cortical BM compared to striatal BM. Moreover, it emphasized the interest of [64Cu][Cu(ATSM)] PET to characterize TME of BM and depict inter-metastasis heterogeneity that could be useful to guide treatments.

Pulmonary artery imaging with 68 Ga-FAPI-04 in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

The feasibility and significance of imaging pulmonary artery (PA) remodeling with 68 Ga-fibroblast activating protein inhibitor (FAPI) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) have not yet been addressed.

METHODS

68 Ga-FAPI-04 uptake in the PA and ascending artery was evaluated in 13 patients with CTEPH and 13 matched non-CTEPH controls. The correlations of PA 68 Ga-FAPI-04 uptake and remodeling parameters derived from right heart catheterization (RHC) were analyzed.

RESULTS

Of the 13 patients with CTEPH, nine (69%) showed visually enhanced 68 Ga-FAPI-04 uptake, whereas none of the control subjects had increased 68 Ga-FAPI-04 uptake in the PA. The prevalence of enhanced uptake in the main, lobar, and segmental PAs was 45% (17/38), 33% (16/48), and 28% (44/159), respectively. 68 Ga-FAPI-04 activity in the PA was positively correlated with pulmonary arterial diastolic pressure (r = 0.571, P = 0.041).

CONCLUSION

68 Ga-FAPI-04 has the potential for imaging fibroblast activation in the PA wall, and 68 Ga-FAPI-04 activity in PA is positively correlated with pulmonary arterial diastolic pressure.