64CuCl2 PET/CT as a potential new imaging method in prostate cancer: illusion or reality?

Copper (Cu) is an essential element for many cellular functions, including proliferation and angiogenesis. High serum Cu levels have been demonstrated in patients with neoplasia as well as high intra-tumoral Cu levels have been reported. Preclinical and clinical evidences suggest its use, in the form of 64Copper chloride (64CuCl2), as metabolic PET tracer in cancer diagnosis and therapy. Specifically, the use of 64CuCl2 in human prostate cancer (PCa) evidenced a high uptake of 64CuCl2 in tumoral prostate and involved regional lymph nodes in a staging setting and high sensitivity for local recurrence and lymph nodes detection in restaging, indicating its great potential. However, further and more solid clinical evidences are needed. On the other hand, 64CuCl2 seems to be a promising radiometabolic drug with great cytotoxic abilities on PCa cells. We have collected the most recent and relevant findings on its potential uses and limitations for the study and treatment of PCa, together with its possible translation in daily clinical practice.

The SGK1 Kinase Inhibitor SI113 Sensitizes Theranostic Effects of the 64CuCl2 in Human Glioblastoma Multiforme Cells.

BACKGROUND/AIMS: The importance of copper in the metabolism of cancer cells has been widely studied in the last 20 years and a clear-cut association between copper levels and cancer deregulation has been established. Copper-64, emitting positrons and ß-radiations, is indicated for the labeling of a large number of molecules suitable for radionuclide imaging as well as radionuclide therapy. Glioblastoma multiforme (GBM) is the CNS tumor with the worse prognosis, characterized by high number of recurrences and strong resistance to chemo-radio therapy, strongly affecting patients survival. We have recently discovered and studied the small molecule SI113, as inhibitor of SGK1, a serine/threonine protein kinase, that affects several neoplastic phenotypes and signaling cascades. The SI113-dependent SGK1 inhibition induces cell death, blocks proliferation, perturbs cell cycle progression and restores chemo-radio sensibility by modulating SGK1-related substrates. In the present paper we aim to characterize the combined effects of 64CuCl2 and SI113 on human GBM cell lines with variable p53 expression. METHODS: Cell viability, cell death and stress/authopagic related pathways were then analyzed by FACS and WB-based assays, after exposure to SI113 and/or 64CuCl2. RESULTS: We demonstrate here, that i) 64CuCl2 is able to induce a time and dose dependent modulation of cell viability (with different IC50 values) in highly malignant gliomas and that the co-treatment with SI113 leads to ii) additive/synergistic effects in terms of cell death; iii) enhancement of the effects of ionizing radiations, probably by a TRC1 modulation; iv) modulation of the autophagic response. CONCLUSIONS: Evidence reported here underlines the therapeutic potential of the combined treatment with SI113 and 64CuCl2 in GBM cells.

The current status of novel PET radio-pharmaceuticals in radiotherapy treatment planning of glioma.

Malignant glioma is a primary tumor of the central nervous system, representing a major cause of mortality in a young, productive subset of population. The management of this neoplasm requires aggressive treatments, including radiotherapy. Accurate imaging plays a central role in treatment planning process with curative intent based on radiation therapy. In order to maximize the radiation dose to the tumor and to minimize the damage to the normal surrounding tissue, a reliable identification of viable tumor margins is indeed required. The use of PET in the treatment planning process has become more promising over the years, although many important questions must be addressed. The aim of this article is to critically review the evidence supporting PET in radiotherapy planning, with special emphasis on the role of novel radiopharmaceuticals, comparing its sensitivity and specificity with respect to 18F-FDG and other anatomic imaging modalities.