RESUMO
Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophins group which plays a crucial role in brain development and neurogenesis. In the hypothalamus it is described as playing a role in energy metabolism and feeding behaviour. The hippocampal concentration of BDNF is believed to play an important role in learning and memory, it has a protective role in neurodegeneration and stress responses. BDNF is also known to take part in many other processes, e.g. angiogenesis, proliferation, cell migration and apoptosis. With its receptor TrkB, neurotrophins are important agents that playa role in neural diseases, as well as in cardiovascular and metabolic disorders, such as diabetes mellitus or acute coronary syndrome. Over the last few years, BDNF interaction with TrkB has also been found to be involved in cancer development, including brain, breast, urinary and gastrointestinal cancer. TrkB expression itself has been described as an aggressive neural tumour. BDNF/TrkB signalling takes part in promoting tumour growth and metastasis. The presented review focuses on gastrointestinal cancer and presents the current literature concerning influence of BDNF and TrkB receptor in cancer progression. Special attention is also paid to data confirming the possible role of BDNF/TrkB interaction in chemotherapy resistance. This might present the opportunity to assess the BDNF and TrkB pathway as a possible novel target for anticancer therapies.