Abstract 4303: Bioimaging of multiple elements by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in penile carcinomas
Authors: Muñoz Juan José Augusto Moyano , Drigo Sandra A. , Marchi Fabio , Pessoa Gustavo , Neto Cristovam S. , Guimaraes Gustavo , Arruda Marco A Z , Rogatto Silvia R. 
Published: May 2015

Abstract
Background: Penile cancer (PeCa) is a rare disease associated with a high mortality and morbidity rate. Surgery is usually the clinical procedure used for the local control of this disease, which results in the partial or complete amputation of the organ and consequently in the causation of psychosexual morbidities. The imbalance of trace elements has been shown to contribute to several cancer related mechanisms, including cell proliferation, tumor progression and apoptosis. The laser ablation imaging-ICP-MS (LA(i)-ICP-MS) is a high sensitive method used as a new tool to detect trace elements associated with human cancer.
Aim: The main aim of our study is to develop a biometal imaging technique to map the spatial distribution of selected metals in cryosections of PeCa tissues in comparison to the ones in adjacent non-neoplastic and normal penile tissues.
Methods: Fresh frozen specimens of PeCa (n=3), paired adjacent non-neoplastic tissue (n=1) and normal penile tissues (obtained from autopsy; n=2) were selected and evaluated using LA-ICP-MS, for the identification of the selected trace elements: 23Na, 44Ca, 43Ca, 39K, 24Mg, 31P and 13C (reference element). The instrumental parameters of the method were optimized for the quantification of plasma energy and optimal reaction cell conditions. Experimental parameters were optimized for the speed ablation (µm s-1) and laser beam diameter (mm), energy (mJ) and frequency (Hz).
Results: The tissues were ablated using a spot size of 55µm and a scan speed of 60 µm s-1, which proved to be efficient laser parameters. The mapping of the trace elements revealed both decreased and increased levels of the different traces analyzed in the PeCa tumor cells when compared to the adjacent non-neoplastic and normal penile tissues. The same pattern of elements distribution and counts was observed in the three PeCa specimens analyzed. A lower average of element counts (43Ca/13C ratio=0.085; 44Ca/13C ratio=1.63; 23Na/13C ratio=188.91) was detected in the PeCa tissue when compared to the normal tissues (43Ca/13C ratio=0.48; 44Ca/13C ratio=6.7; 23Na/13C ratio= 336.2). In addition, PeCa presented considerably higher average counts of 24Mg, 39K and 31P (24Mg/13C ratio=18.56; 39K/13C ratio=189.12; 31P/13C ratio=18.27) compared to the normal tissues (24Mg/13C ratio=8.15; 39K/13C ratio=13.23; 31P/13C ratio=4.54).
Conclusions: LA-ICP-MS mapping is a powerful and useful method to provide novel information regarding the spatial distribution of elements in penile tumors and their implication in tumorigenesis.
Note: This abstract was not presented at the meeting.
Citation Format: Juan José Augusto Moyano Muñoz, Sandra A. Drigo, Fabio Marchi, Gustavo Pessoa, Cristovam S. Neto, Gustavo Guimaraes, Marco A Z Arruda, Silvia R. Rogatto. Bioimaging of multiple elements by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in penile carcinomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4303. doi:10.1158/1538-7445.AM2014-4303