The Interactions among Hypertension, Cancer, and COVID-19: Perspective with Regard to Ca²⁺/cAMP Signalling

Background: The hypothesis that hypertension is clinically associated with an enhanced risk of developing cancer has been highlighted. However, the working principles involved in this link are still under intensive discussion. A correlation among inflammation, hypertension, and cancer could accurately describe the clinical link between these diseases. In addition, dyshomeostasis of Ca²⁺ has been considered to be involved in both cancer and hypertension, and inflammation. There is a strong link between Ca²⁺ signalling, e.g. enhanced Ca²⁺ signals, and inflammatory outcomes. cAMP also modulates pro- and anti-inflammatory outcomes; pharmaceuticals, which increase intracellular cAMP levels, can decrease the production of proinflammatory mediators and enhance the production of antiinflammatory outcomes. Objective: This article highlights the participation of Ca²⁺/cAMP signalling in the clinical association among inflammation, hypertension, and an enhanced risk for the development of cancer. In addition, considering that research on coronavirus disease 2019 (COVID-19) is a rapidly evolving field, this article also reviews recent reports related to the role of Ca²⁺ channel blockers in restoring Ca²⁺ signalling disruption due to COVID-19, including the relationship among COVID-19, cancer, and hypertension. Conclusion: An understanding of the association among these diseases could expand current pharmacotherapy, involving Ca²⁺ channel blockers and pharmaceuticals that facilitate a rise in cAMP levels.