Although resistance exercise (RE) is now recognized as an adjuvant in cancer treatment because of its capacity to prevent muscle wasting, weakness, and cachexia, it is unknown whether RE can mitigate tumor development. Two solid adenocarcinoma models (Walker-256 and Ehrlich) were used to investigate the effects of RE on tumor cell proliferation, growth, and aggressiveness parameters in tumor-bearing animals’ life span.
Walker-256 tumor-bearing rats and Ehrlich tumor-bearing mice were subjected to RE, which consisted of climbing a ladder apparatus with loads tied to their tails. After 4 wk, animals were euthanized, and tumors were excised and assessed for tumor microenvironment evaluation such as cell proliferation and apoptosis determination, collagen deposit, and presence of malignant tumor morphology.
Our data demonstrate that RE mitigated tumor growth and favored tumor end points such as lower Scarff–Bloom–Richardson histological grade tumor, denoting slow cell aberrant form and division, decreased tumor cell proliferation (evaluated by nucleus marked with antigen ki-67), and lower viable tumor area in both types of tumors studied. In addition, RE stimulated tumor microvessel density in Walker-256 tumor-bearing rats, but there was no change in their life span.
RE may mitigate tumor growth and tumor malignancy parameters such as lower histopathological grade, assuming less nuclear pleomorphism and mitotic cells, smaller viable tumor area, and decreased tumor cell proliferation in both adenocarcinomas. In addition, RE induced tumor vascularization.
1Department of Physical Education, State University of Londrina, Londrina, PR, BRAZIL
2Department of General Pathology, State University of Londrina, Londrina, PR, BRAZIL
3Graduate Program of Health Sciences, Faculty of Medicine, Federal University of Mato Grosso, Cuiabá, BRAZIL
4Brazilian National Institute of Cancer, Rio de Janeiro, RJ, BRAZIL
5Faculty of Sport, University of Porto, CIAFEL, Porto, PORTUGAL
Address for correspondence: Rafael Deminice, Ph.D., Department of Physical Education, Faculty of Physical Education and Sport, State University of Londrina, Rodovia Celso Garcia Cid, Pr 445 Km 380, Campus Universitário, Londrina, Paraná, Brazil; E-mail: email@example.com.
C. S. P. and M. T. T. contributed equally to this work.
Submitted for publication January 2019.
Accepted for publication April 2019.
Online date: April 13, 2019