The neuronal influence on tumor progression

Abstract

Nerve fibers accompany blood and lymphatic vessels all over the body. An extensive amount of knowledge has been obtained with regard to tumor angiogenesis and tumor lymphangiogenesis, yet little is known about the potential biological effects of "neoneurogenesis". Cancer cells can exploit the advantage of the factors released by the nerve fibers to generate a positive microenvironment for cell survival and proliferation. At the same time, they can stimulate the formation of neurites by secreting neurotrophic factors and axon guidance molecules. The neuronal influence on the biology of a neoplasm was initially described several decades ago. Since then, an increasing amount of experimental evidence strongly suggests the existence of reciprocal interactions between cancer cells and nerves in humans. Moreover, researchers have been able to demonstrate a crosstalk between cancer cells and nerve fibers as a strategy for survival. Despite all these evidence, a lot remains to be done in order to clarify the role of neurotransmitters, neuropeptides, and their associated receptor-initiated signaling pathways in the development and progression of cancer, and response to therapy. A global-wide characterization of the neurotransmitters or neuropeptides present in the tumor microenvironment would provide insights into the real biological influences of the neuronal tissue on tumor progression. This review is intended to discuss our current understanding of neurosignaling in cancer and its potential implications on cancer prevention and therapy. The review will focus on the soluble factors released by cancer cells and nerve endings, their biological effects and their potential relevance in the treatment of cancer.

Dopamine Receptor Gene (DRD1-DRD5) Expression Changes as Stress Factors Associated with Breast Cancer

“…These types of events occur due to secretion of catecholamines (stress-mediators) which increases in response to stressful events (Ganguly, 2010;Beaulieu and Gainetdinov, 2011). Most of catecholamines including epinephrine and norepinephrine are related to carcinogenesis and tumor progression (Mancino et al, 2011). In addition, there is a close relationship between immune and nervous systems.…”

“…Previous study demonstrated that mental and physiological conditions of individuals are important in the promotion and development of cancers and changes in patient's life style could be effective in incidence of stress (Cohen et al, 2007;Mancino et al, 2011;Barik et al, 2013). Cancer cells and nerve fibers have cross-talks and thus could influence on each other.…”

“…Chronic stress has an important role in evidence of cancers specially breast cancer and cause to secretion of neurotransmitters. Numerous studies showed the role of neurotransmitters in the occurrence and progression of cancers which is mediated by their various types of receptors (Elenkov et al, 2000;Marsh et al, 2010;Mancino et al, 2011). In general, the nerve fibers are interconnected with lymphatic and blood vessels (Elenkov et al, 2000).…”

“…One of these neurotransmitters is dopamine which has proliferative effects in non-transformed cells (Mancino et al, 2011). Whereas, some of neurotransmitters particularly dopamine can inhibit the T cell receptor (TCR)-induced cell proliferation and stimulation of T cells to secretion of cytokines and consequently leads immune system depletion (Basu et al, 2010).…”

“…Recently, several studies have shown that different mediators of the nervous system like neurotransmitters have an important role in immune system functions, lymphocyte migration and tumor angiogenesis, lymphogenesis and progression. Several neurotransmitters may lead to tumor progression via stimulating the migration and dissemination of tumor cells to distant sites (Mancino et al, 2011;Hejazi et al, 2014).…”