Intracellular distribution and stability of a luminescent rhenium(i) tricarbonyl tetrazolato complex using epifluorescence microscopy in conjunction with X-ray fluorescence imaging

Abstract

Optical epifluorescence microscopy was used in conjunction with X-ray fluorescence imaging to monitor the stability and intracellular distribution of the luminescent rhenium(i) complex fac-[Re(CO)(phen)L], where phen = 1,10-phenathroline and L = 5-(4-iodophenyl)tetrazolato, in 22Rv1 cells. The rhenium complex showed no signs of ancillary ligand dissociation, a conclusion based on data obtained via X-ray fluorescence imaging aligning iodine and rhenium distributions. A diffuse reticular localisation was detected for the complex in the nuclear/perinuclear region of cells, by either optical or X-ray fluorescence imaging techniques. X-ray fluorescence also showed that the rhenium complex disrupted the homeostasis of some biologically relevant elements, such as chlorine, potassium and zinc.

Intracellular Localization of an Osmocenyl‐Tamoxifen Derivative in Breast Cancer Cells Revealed by Synchrotron Radiation X‐ray Fluorescence Nanoimaging

“…[6] As such, they were shown to inhibit thioredoxin reductase (TrxR), as elenoenzyme involved in the cellular redox balance, in vitro and in Jurkat cells. [4,7] Here we use state-of-the-art synchrotron radiation X-ray fluorescence (SR-XRF) nanoimaging [8][9][10][11] to quantitatively trace the intracellular distribution of metal-based drugs at biologically relevant concentrations in al abel-free fashion. Them etallodrug,a nd the endogenous elements in MDA-MB-231 cells,exposed for 1h or 24 hto2mm Oc-OH-Tam, were mapped.…”

Cytotoxicity, cellular localization and photophysical properties of Re(I) tricarbonyl complexes bound to cysteine and its derivatives

“…In the present study, it is particularly difficult to pinpoint the exact position of complex 1 in the cells in Figs. 6 and S9(a), other than being present in the nuclear and/or perinuclear region, as the distribution images themselves are two-dimensional projection of three dimensional objects in dried cells [78]. This also applies to quantification of elemental concentrations shown in Fig.…”

“…Rhenium accumulation in the nuclear and/or perinuclear region of these cells is evident. The nuclear region can be identified via morphology in the optical image, as well as by the presence of zinc and phosphorous, which are predominantly found in the nucleus in zinc finger proteins and in the DNA backbone, respectively [46,78]. When comparing the Zn and Re maps in cells treated with 1, there appears to be some overlap between the Zn and Re signals in the nuclear regions of 1-A and 1-B, indicating that these two elements to some extent co-localize in these cells.…”

“…Data were analyzed with a one-way ANOVA, followed by Dunnet post-tests from comparisons between treated and control cells (phen = 1,10′-phenanthroline; L = 5-(4-iodophenyl)tetraazolate), also revealed using the XFM technique that Re was localized within the diffuse reticular network in the nuclear and/or perinuclear region in 22Rv1 cells, and that the complex remained intact after uptake. Earlier studies had shown that cellular localization of such complexes varied depending on the substitution group on the aryltetrazolate ligand [78].…”

Graftable SCoMPIs enable the labeling and X-ray fluorescence imaging of proteins

“…Very recently, Massi and Harris have shown that Re complexes can be mapped at the single cell level by XRF. 29 However, X-ray fluorescence molecular tags or probes that can be grafted onto target biomolecules and that do not modify to a large extent their physico-chemical properties are still needed.…”