Roberta G. Leitão

Study of human prostate spheroids treated with zinc using X ray microfluorescence

Prostate cancer is the most frequently diagnosed type of cancer in men and the second leading cause of their cancer death in many countries. Human tumor cells cultured in three dimensions display increased pro-angiogenic capacities and resistance to interferons, chemotherapeutic agents or irradiation, as compared with cells cultured in two dimensional monolayers. In this study, we investigated Zn distribution in prostate cancer spheroids (DU145) and analyzed the differences in the response to Zinc (0-150 μM) treatment using X-ray microfluorescence with Synchrotron Radiation (SRμXRF). The measurements were performed in standard geometry of 45° incidence, exciting with a white beam and using an optical capillary with 20 μm diameter collimation in the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results showed non-uniform distribution of Zn in all the spheroids analyzed. Zn treatment showed a decrease in Zn intensity with the increase of its concentration in DU145 spheroids. The differential response to zinc of DU145 cell spheroids suggests that zinc may have an important role in prostate cancer.

Contribution of X-Ray Imaging Microscopy in Metal Bioaccumulation Studies

Industrialization, urbanization, agriculture and natural resource exploration activities are the main sources of release of pollutants, which contaminate both the aqueous compartment and the sediment. In general, metals are the major pollutant, and 90 % approximately of the heavy metals bind to mineral particles, organic matter and to microbial biofilm. The sufficient bioavailability of contaminants can result in bioaccumulation and, depending on the contaminant level, most marine sedimentary ecosystems can become toxic and/or presumably extinct. The knowledge of the physiological mechanisms and the investigation of how these organisms deal with the bioaccumulation of heavy metals are the key in order to unlock adaptive processes, which contribute to the evolutionary fitness and permanence of the species in the environment. In this context, X-ray fluorescence microscopy with Synchrotron radiation with tomography assessment (3D images) was used in order to mapping the body heavy metal distribution of a high abundant marine worm from Guanabara Bay, which is a chronic heavy metal polluted area located at Rio de Janeiro, Brazil. Cadmium, nickel, chromo and cooper were investigated and the results showed a bioaccumulation in the inner parts and especially at the anterior region of the organism. Therefore, X-ray imaging techniques can be a useful tool in order to investigate bioaccumulation in marine benthic invertebrates.

Study of Response to Zinc in Human Prostate Spheroids Using X-Ray Microfluorescence

Diseases of the prostate gland are the most frequently diagnosed in men after middle age. Spheroid cell culture is a useful technique for tissue engineering or regenerative medicine research, pharmacological and toxicological studies, and fundamental studies in cell biology. In this paper, we investigated zinc distribution in cell spheroids in benign prostate hyperplasia (BPH) and prostate cancer (PCa) (DU145) and analyzed the differences in the response to zinc (0-150 μM) treatment using μXRF with synchrotron radiation. The results showed nonuniform distribution of Zn in all the spheroids analyzed. The differential response to zinc of BPH and DU145 cell spheroids suggests that zinc may have an important role in PCa.

Elemental Distribution of Prostate Samples by Synchrotron Radiation X-Ray Fluorescence Techniques

Synchrotron X-ray imaging systems with fluorescence techniques were developed for biomedical research at the Brazilian Synchrotron Laboratory. Two different X-ray fluorescence systems were implemented to analyze human prostate samples with and without disorders.

Spatial distribution of elements in the spheroids by prostate tumor cells using synchrotron radiation x-ray fluorescence

The formation of three-dimensional cell microspheres such as spheroids has attracted attention as a useful culture technique. In this study, we investigated the trace elemental distribution (mapping) in spheroids derived from tissue prostate cancer (PCa). The measurements were performed in standard geometry of 45° incidence, exciting with a white beam and using an optical capillary with 20 μm diameter collimation in the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results showed that most elements analyzed presented non-uniform distribution. P, S and Cl showed similar elemental distribution in all the samples analyzed. K, Ca, Fe, and Cu showed different elemental distribution for the spheroids analyzed. Zinc presented more intense distributions in the spheroid central region for all spheroids analyzed.