ABSTRACT
Aim: To summarize current knowledge, gaps, quality of the evidence and show main results related to the role of the autonomic nervous system in lung cancer. Methods: Studies were identified through electronic databases (PubMed, Scopus, Embase and Cochrane Library) in October 2023, and a descriptive analysis was performed. Twenty-four studies were included, and most were observational. Results: Our data indicated an increased expression of ß-2-adrenergic receptors in lung cancer, which was associated with poor prognosis. However, the use of ß-blockers as an add-on to standard treatment promoted enhanced overall survival, recurrence-free survival and reduced metastasis occurrence. Conclusion: Although the results herein seem promising, future research using high-quality prospective clinical trials is required to draw directions to guide clinical interventions.
Lung cancer is one of the most common causes of cancer-related deaths in the world, which often goes undiagnosed until it is in an advanced stage. Recently, the autonomic nervous system (sympathetic and parasympathetic nervous systems) has been identified as a regulator of cancer growth and spread, including lung cancer. In fact, preclinical studies have demonstrated that autonomic innervation in lung cancer can trigger tumor progression, metastasis, and resistance to treatment, worsening the prognosis. In this sense, add-on strategies to standard cancer treatments have been investigating and one of them has stood out: the incidental use of ß-blockers (patients who used ß-blockers for the treatment of hypertension and/or cardiovascular diseases or anxiety) before surgeries or during chemotherapy, which has been associated with improved clinical outcomes. Thus, a scoping review was conducted to summarizing the current knowledge about the quality of evidence, gaps and main results related to the role of the autonomic nervous system in human lung cancer. Data from this review indicated an increase in sympathetic nervous system receptors associated with a worse prognosis in patients with lung cancer. Indeed, those patients who took ß-blockers along with lung cancer treatment showed an increase in survival and a reduction in the occurrence of metastases. Although the results herein seem promising, further prospective clinical studies are needed to investigate the effect of the intentional and controlled use of ß-blockers as an add-on strategy on the treatment of different types and stages of lung cancer.
ABSTRACT
AIMS: The current study tested the hypotheses that 1) an acute bout of aerobic exercise impairs isolated skeletal muscle contractile properties and 2) N-acetylcysteine (a thiol antioxidant; NAC) administration can restore the impaired muscle contractility after exercise. MAIN METHODS: At rest or immediately after an acute bout of aerobic exercise, extensor digitorum longus (EDL) and soleus muscles from male Wistar rats were harvested for ex vivo skeletal muscle contraction experiments. Muscles from exercised animals were incubated in Krebs Ringer's buffer in absence or presence of 20mM of NAC. Force capacity and fatigue properties were evaluated. KEY FINDINGS: Exercised EDL and soleus displayed lower force production across various stimulation frequencies (p<0.001), indicating that skeletal muscle force production was impaired after an acute bout of exercise. However, NAC treatment restored the loss of force production in both EDL and soleus after fatiguing exercise (p<0.05). Additionally, NAC treatment increased relative force production at different time points during a fatigue-induced protocol, suggesting that NAC treatment mitigates fatigue induced by successive contractions. SIGNIFICANCE: NAC treatment improves force capacity and fatigue properties in ex vivo skeletal muscle from rats submitted to an acute bout of aerobic exercise.