Alterations in Low-Z Elements Distribution in Heart Tissue after Treatments to Breast Cancer Using LEXRF Technique

Andrea Mantuano,Camila Salata,Delson Braz,Samara Ferreira-Machado,Alessandra Gianoncelli,Marcos Vinicius Colaço,Arissa Pickler,Regina Cely Barroso,Carla Lemos Mota,Liebert Parreiras Nogueira,Carlos Eduardo De Almeida

doi:10.4236/ajac.2016.711068

Abstract

Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for the BC, including chemotherapy and/or radiotherapy, increased the survival rates for this type of cancer. One late complication induced by BC treatment is the cardiotoxicity. This term comprises different cardiotoxic side effects, which include blood pressure alterations, myocardial ischemia, congestive heart failure and other damages. This study aimed to evaluate the cardiac alterations induced by radiotherapy and chemotherapy, simulating a treatment for BC in Wistar rats. It is, therefore, important to understand the mechanisms involved in the cardiotoxicity, in order to prevent women from this late effect, when they undergo BC treatments. The major interests in this work are in Low atomic weight elements as Sodium, because it is strongly related to cardiomyocyte contraction; Magnesium, because it is important in the cardiac metabolism; and Iron, because BC treatment induced cardiotoxicity can be associated to the oxidative stress. Changes that occur in unhealthy tissues in case to cardiovascular damages can be better understood when elemental compounds and structures of healthy tissues are known. Low Energy X-ray Fluorescence (LEXRF) technique was used to obtain elemental maps of low Z-elements providing a semi-quantitative analysis of the tissues evaluated under different conditions. Through the technique LEXRF we obtained elemental and absorption maps. The results showed more damages when associating chemotherapy and radiotherapy in comparison to myocardium healthy. Those images taken together with light microscopy, X-ray absorption and phase contrast images, satisfactorily characterize the cardiac tissue for the first time in the literature, from the structural and morphological points of view. LEXRF was carried out at TwinMic beamline in the ELETTRA Synchrotron Fa-cility, at the beamline TwinMic, in Trieste, Italy.

Highlights

Soft X-rays can provide better contrast in absorption imaging than hard X-rays as a result of the high absorption cross sections of C, N and O Kα shells, the main organic matter constituents, in the soft X-ray regime [1].A combination of compositional and morphological information can be used to make a semiquantitative investigation able to identify reliable marker elements and to better understand some aspects of healthy tissues and tissues treated with chemotherapy and/or radiotherapy [2] [3].Several studies about cellular organization and caracterization are reported in literature
The major interests in this work are in Low atomic weight elements as Sodium, because it is strongly related to cardiomyocyte contraction; Magnesium, because it is important in the cardiac metabolism; and Iron, because breast cancer (BC) treatment induced cardiotoxicity can be associated to the oxidative stress
Images of light microscopy and Low Energy X-ray Fluorescence (LEXRF) images were obtained for each group

Summary

Introduction

Soft X-rays can provide better contrast in absorption imaging than hard X-rays as a result of the high absorption cross sections of C, N and O Kα shells, the main organic matter constituents, in the soft X-ray regime [1].A combination of compositional and morphological information can be used to make a semiquantitative investigation able to identify reliable marker elements and to better understand some aspects of healthy tissues and tissues treated with chemotherapy and/or radiotherapy [2] [3].Several studies about cellular organization and caracterization are reported in literature. Le Gros, M.A., et al, 2012 [4] used soft X-ray tomography to visualize cells in three dimensions, obtaining remarkable images This technique does not allow identifying the elemental distribution. X-ray fluorescence microprobe, X-ray Fluorescence Microscopy and Dynamic Contrast-enhanced MR Imaging, are used to establish elemental concentrations for a large number of different chemical elements simultaneously in different locations in cell and tissue samples [5]. Those techniques provide trace element sensitivity using hard Xrays, an opportunity to image whole cells and quantify high-Z elements on a per cell basis

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