The expression of neurotrophins (NTs) and related high- and low-affinity receptors was studied in surgical samples of histologically diagnosed human tumors of the lower respiratory tract. The experiment was conducted with 30 non-small cell lung cancer specimens and in eight small cell lung cancer specimens by Western blot analysis and immunohistochemistry to assess expression and distribution of NT and NT receptor proteins in tissues examined. Immunoblots of homogenates from human tumors displayed binding of anti-nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and NT-3 antibodies as well as of anti-tyrosine-specific protein kinase (Trk) A, TrkB, and TrkC receptor antibodies, with similar migration characteristics than those displayed by human beta-NGF and proteins from rat brain. A specific immunoreactivity for NTs and NT receptors was demonstrated in vessel walls, stromal fibroblasts, immune cells, and sometimes within neoplastic cell bodies. Approximately 33% of bronchioloalveolar carcinomas exhibited a strong membrane NGF and TrkA immunoreactivity, whereas 46% adenocarcinomas expressed an intense TrkA immunoreactivity but a weak immunostaining for NGF within tumor cells. Moreover, squamous cell carcinomas developed an intense TrkA immunoreactivity only within stroma surrounding neoplastic cells. A faint BDNF and TrkB immunoreactivity was documented in adenocarcinomas, squamous cell carcinomas, and small cell lung cancers. NT-3 and its corresponding TrkC receptor were found in a small number of squamous cell carcinomas within large-size tumor cells. No expression of low-affinity p75 receptor protein was found in tumor cells. The detection of NTs and NT receptor proteins in tumors of the lower respiratory tract suggests that NTs may be involved in controlling growth and differentiation of human lung cancer and/or influencing tumor behavior.
Among the scientific communities, there is a convergence of results supporting a direct relationship between dysregulated sialylation and poor prognosis in many human cancers. For this reason, we have retrospectively investigated 169 cases of invasive ductal carcinoma of the breast, coming from female patients aged between 31 and 76 years old. The whole series was subdivided into two prognostic groups: the first group consisted of 138 patients, who showed a post-treatment survival time more than 5 years, while the second group was made up by 31 patients, died within 5 years despite of chemotherapy. All the surgical specimens were fixed in 10 % neutral buffered formalin, paraffin embedded and, then, submitted to routinely haematoxylin/eosin staining and to a further histochemical (Alcian Blue, DDD-Fast Blue B, Mercury Orange), immunohistochemical (ST3GAL5 sialyltransferase, Ki67, c-erbB2, ER, PR) and chemico-elemental characterization. In the 31 cases of breast cancer belonging to the second group, an overexpression of sialomucins and sialyltransferases has been detected. Our results lead us to support that in aggressive chemoresistant breast cancers, the altered expression of sialic acid, due to an uncontrolled sialylation, creates an excessive negative charge on cell membranes, which stimulates repulsion between neoplastic cells and their subsequent access into the blood stream. This event implies an early metastatization and a rapid disease progression with fatal outcome. The early application of Alcian Blue stain on diagnostic biopsies of breast cancer is able to cheaply reveal the sialomucin accumulations, providing for the disease course.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.