Numerous studies have firmly established the role of ion channels in essentially all basic cellular functions. Apart from their role in ion transport, they can form macromolecular complexes with adhesion proteins, and signaling molecules. Ion channels are not only responsible for cellular electrogenesis and excitability, but they also regulate the necessary conditions for tissue homeostasis, such as differentiation, proliferation and apoptosis. Although cancer is not officially classified as a channelopathy, it has been increasingly recognized that ion channel aberrations play an important role in virtually all cancer types. Ion channels can exert pro-tumorigenic activities due to genetic or epigenetic alterations, or as a response to molecular signals, such as growth factors, hormones, etc. Prostate cancer is the second leading cause of cancer-related death in men in the United States. Increasing evidence suggests that ion channels and pumps play a critical role in the regulation of prostate cancer cell proliferation, apoptosis evasion, migration, epithelial-to-mesenchymal transition and angiogenesis. There is also evidence suggesting that ion channels might play a role in treatment failure in prostate cancer. Hence, they represent promising targets for diagnosis, staging and treatment. Here, the role of major types of ion channels involved in the development and progression of prostate cancer were reviewed. Identifying the underlying molecular mechanisms of the pro-tumorigenic effects of ion channels, may potentially inform the development of novel therapeutic strategies to counter this malignancy.

Background: The identification of new cellular receptors has been increasing rapidly. A receptor is called “orphan” if an endogenous ligand has not been identified yet. Methods: Here we review receptors that contribute to prostate cancer and are considered orphan or partially orphan. This means that the full spectrum of their endogenous ligands remains unknown. Results: The orphan receptors are divided into two major families. The first group includes G protein-coupled receptors. Most are orphan olfactory receptors. OR51E1 inhibits cell proliferation and induces senescence in prostate cancer. OR51E2 inhibits prostate cancer growth, but promotes invasiveness and metastasis. GPR158, GPR110 and GPCR-X play significant roles in prostate cancer development and progression. However, GPR160 induces cell cycle arrest and apoptosis. The other major subset of orphan receptors are nuclear receptors. RORα inhibits tumor growth, but RORγ stimulates androgen receptor signaling. PXR contributes to metabolic deactivation of androgens and inhibits cell proliferation. TLX has pro-tumorigenic effects in prostate cancer, while its knockdown triggers cellular senescence and growth arrest. Estrogen-related receptor ERRγ can inhibit tumor growth but ERRα is pro-tumorigenic. Dax1 and Shp are also inhibitory in prostate cancer. Conclusion: There is a “zoo” of relatively underappreciated orphan receptors that play key roles in prostate cancer.

Preclinical evidence suggests that voltage gradients can act as a kind of top-down master regulator during embryogenesis and orchestrate downstream molecular-genetic pathways during organ regeneration or repair. Moreover, electrical stimulation shifts response to injury towards regeneration instead of healing or scarring. Cancer and embryogenesis not only share common phenotypical features, but also commonly upregulated molecular pathways. Ion channel activity is directly or indirectly linked to the pathogenesis of cancer hallmarks, while experimental and clinical studies suggest that their modulation may exert antitumor effects. A large recent clinical trial served as a proof-of-principle for the benefit of preoperative use of topical sodium channel blockade as a potential anticancer strategy against early human breast cancers. Apart from the obvious importance in perioperative medicine, it calls for the planning of further carefully designed clinical trials to expand on the concept of ion channels as tumor drivers.

Background: The clinical impact of vasopressin in hemorrhagic shock remains largely unknown. Objective: This systematic review and meta-analysis was designed to investigate the effects of vasopressin receptor agonists during the resuscitation of hemorrhagic shock. Methods: A systematic search of PubMed (MEDLINE), Scopus, and PubMed Central was conducted for relevant articles. Preclinical (animal) and clinical studies were included. The primary objective was to investigate the correlation of vasopressin receptor agonist use with mortality and various hemodynamic parameters. Results: Data extraction was possible in 13 animal studies and two clinical studies. Differences in risk of mortality between patients who received a vasopressin receptor agonist were not statistically significant when compared to those who were not treated with such agents [RR (95%CI): 1.17 (0.67, 2.08); p=0.562; I2 = 50%]. The available data were insufficient to conduct a meta-analysis assessing the effect of vasopressin receptor agonists on hemodynamics. Drawing safe conclusions from animal studies was challenging, due to significant heterogeneity in terms of species and dosage of vasopressin receptor agonists across studies. Conclusions: Differences in risk of mortality between patients who received a vasopressin receptor agonist were not statistically significant when compared to those who were not treated with such agents after hemorrhagic shock.

Elevated resting heart rate is frequently observed in cancer patients, and is associated with increased mortality. Although specific chemotherapeutic agents can induce cardiotoxicity, the presence of sinus tachycardia in chemotherapy-naive patients suggests other factors likely contribute to this clinical presentation. Despite its prevalence, cancer-associated resting sinus tachycardia has not been fully recognized and comprehensively described as a separate clinical entity. Secondary effects of cancer, especially structural cardiac changes, secretory factors (inflammatory cytokines), and thromboembolic disease can cause resting tachycardia. Alternatively, rapid heart rate may reflect compensatory mechanisms responding to increased metabolic demands, raised cardiac output states, and even pain. Hence, cancer-associated tachycardia presents a clinical dilemma; acute life-threatening conditions (such as sepsis, pulmonary embolism, etc.) must be ruled out, but cancer itself can explain resting sinus tachycardia and more conservative management can avoid unnecessary testing, cost and patient stress. Furthermore, identification and management of cardiac conditions associated with cancer may improve survival and the quality of life of cancer patients.