Not always a miracle - The case of the missing metastasis.

Spontaneous regression of malignant neoplasms is extremely rare, but renal cell carcinomas (RCC) are most often associated with this phenomenon. We report a case of a patient with personal history of RCC, who underwent nephrectomy and no other oncological treatment. One year after nephrectomy, a lung metastasis was detected and kept under follow-up for 3 years. Its size increased over time until a needle biopsy was performed, and its metastatic nature confirmed. Wedge resection of the lung nodule was performed, and no neoplastic cells were found, suggesting its spontaneous regression after biopsy. Different theories have been proposed to explain this phenomenon and, in most cases, the mechanism seems to involve the activation of the immune system. This case supports the importance of reducing tumor burden and the impact of the disturbance of the tumor microenvironment caused by instrumentation, in improving immune system activation and its essential role in neoplasm regression.

Novel insights into the role of urotensin II in cardiovascular disease.

Urotensin II (UII) is a vasoactive peptide that interacts with a specific receptor called the UT receptor. UII has been implicated in cardiovascular regulation, with promising therapeutic applications based on UT receptor antagonism. The endogenous ligands of the UT receptor: UII and urotensin-related peptide (URP), differentially bind and activate this receptor. Also, the receptor localization is not restricted to the plasma membrane, possibly inducing different physiological responses that could support its inconsistent, but potent, vasoactive activity. These properties could explain the disappointing outcomes in clinical studies, in contrast to the positive preclinical results regarding heart failure, pulmonary hypertension, atherosclerosis and diabetes mellitus. These aspects should be considered in future investigations to a better comprehension of the role of UII as a potential therapeutic target.