<abstract xmlns="http://www.w3.org/1999/xhtml"><bold>Objectives.</bold> Previously we have shown that 20 days after the tumor cells injection smaller melanomas have been developed in chemically sympathectomized mice in comparison with animals having intact sympathetic nervous system. However, it is known that chemical sympathectomy reduces the sympathetic neurotransmission only temporarily. In the present study, we monitored the survival of the sympathectomized mice with melanoma with an attempt to find out how long the suppressing effect of sympathectomy on the melanoma growth may endure.<bold>Methods.</bold> The chemical sympathectomy was performed by intraperitoneal injection of neurotoxin 6-hydroxydopamine in male C57BL/6J mice. Seven days later, the animals were injected subcutaneously with B16-F10 melanoma cells. Then, melanoma development, survival of the tumor-bearing mice and weight of the developed tumor mass were analyzed.<bold>Results.</bold> Sympathectomy delayed the development of the palpable tumors (18th day vs.14th day) and significantly prolonged the survival of the tumor-bearing mice (median 34 days vs. 29 days). However, the weight of the developed melanoma was significantly increased in the sympathectomized mice in comparison with the animals having intact sympathetic nervous system.<bold>Conclusions.</bold> The data of the present study showed that effect of the chemical sympathectomy, performed before the tumor growth induction, persisted even at the time when sympathetic nerves started to regenerate that resulted in a prolonged survival of the mice with melanoma. However, comparing to our previous study, in which we have shown a reduced tumor mass in earlier stages of the tumor growth, specifically 20 days after melanoma cells injection, now we indicate that in later stages of the melanoma progression, the tumor mass was significantly increased in sympathectomized animals. These contra-intuitive findings may indicate that interventions affecting the sympathetic nervous system may exert complex effect on the tumor progression. Based on these data we may suggest that the potential therapeutic interventions affecting the sympathetic signaling in the tumor tissue and its microenvironment should attenuate the sympathetic neurotransmission not only temporarily but till the complete regression of the tumor tissue.</abstract>

Objectives. Previously we have shown that 20 days after the tumor cells injection smaller melanomas have been developed in chemically sympathectomized mice in comparison with animals having intact sympathetic nervous system. However, it is known that chemical sympathectomy reduces the sympathetic neurotransmission only temporarily. In the present study, we monitored the survival of the sympathectomized mice with melanoma with an attempt to find out how long the suppressing effect of sympathectomy on the melanoma growth may endure.Methods. The chemical sympathectomy was performed by intraperitoneal injection of neurotoxin 6-hydroxydopamine in male C57BL/6J mice. Seven days later, the animals were injected subcutaneously with B16-F10 melanoma cells. Then, melanoma development, survival of the tumor-bearing mice and weight of the developed tumor mass were analyzed.Results. Sympathectomy delayed the development of the palpable tumors (18th day vs.14th day) and significantly prolonged the survival of the tumor-bearing mice (median 34 days vs. 29 days). However, the weight of the developed melanoma was significantly increased in the sympathectomized mice in comparison with the animals having intact sympathetic nervous system.Conclusions. The data of the present study showed that effect of the chemical sympathectomy, performed before the tumor growth induction, persisted even at the time when sympathetic nerves started to regenerate that resulted in a prolonged survival of the mice with melanoma. However, comparing to our previous study, in which we have shown a reduced tumor mass in earlier stages of the tumor growth, specifically 20 days after melanoma cells injection, now we indicate that in later stages of the melanoma progression, the tumor mass was significantly increased in sympathectomized animals. These contra-intuitive findings may indicate that interventions affecting the sympathetic nervous system may exert complex effect on the tumor progression. Based on these data we may suggest that the potential therapeutic interventions affecting the sympathetic signaling in the tumor tissue and its microenvironment should attenuate the sympathetic neurotransmission not only temporarily but till the complete regression of the tumor tissue.

Sympathectomized tumor-bearing mice survive longer but develop bigger melanomas

Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava,

Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava,

Endocrine Regulations

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Sympathectomized tumor-bearing mice survive longer but develop bigger melanomas"}

Objectives. Previously we have shown that 20 days after the tumor cells injection smaller melanomas have been developed in chemically sympathectomized mice in...

Sympathectomized tumor-bearing mice survive longer but develop bigger melanomas

Published Online: Dec 08, 2016

Page range: 207 - 214

DOI: https://doi.org/10.1515/enr-2016-0022

Keywords
6-hydroxydopamine, B16-F10 melanoma cells, melanoma development and growth, tumor weight

© 2016 Horvathova L et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Sympathectomized tumor-bearing mice survive longer but develop bigger melanomas

Published Online: Dec 08, 2016

Page range: 207 - 214

DOI: https://doi.org/10.1515/enr-2016-0022

Keywords6-hydroxydopamine, B16-F10 melanoma cells, melanoma development and growth, tumor weight

© 2016 Horvathova L et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
6-hydroxydopamine, B16-F10 melanoma cells, melanoma development and growth, tumor weight