STIM-Orai Channels and Reactive Oxygen Species in the Tumor Microenvironment

• Published in: Cancers Vol. 11; no. 4; p. 457
• Main Authors: Frisch, Janina, Angenendt, Adrian, Hoth, Markus, Prates Roma, Leticia, Lis, Annette
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30-03-2019; MDPI
• Subjects: Apoptosis; Blood vessels; Calcium channels; Calcium influx; Cancer; Cell fate; Cell growth; Cell migration; Cell proliferation; Chemokines; Cytokines; Extracellular matrix; Gene expression; Growth factors; Hepatitis B; Hypoxia; Immune response; Ischemia; Liver cancer; Medical prognosis; Metabolism; Metastasis; Mutation; Reactive oxygen species; Review; Tumor cells; Tumor microenvironment; Tumors; STIM; calcium; tumor microenvironment; H2O2; Orai; reactive oxygen species
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers11040457

The tumor microenvironment (TME) is shaped by cancer and noncancerous cells, the extracellular matrix, soluble factors, and blood vessels. Interactions between the cells, matrix, soluble factors, and blood vessels generate this complex heterogeneous microenvironment. The TME may be metabolically beneficial or unbeneficial for tumor growth, it may favor or not favor a productive immune response against tumor cells, or it may even favor conditions suited to hijacking the immune system for benefitting tumor growth. Soluble factors relevant for TME include oxygen, reactive oxygen species (ROS), ATP, Ca
, H⁺, growth factors, or cytokines. Ca
plays a prominent role in the TME because its concentration is directly linked to cancer cell proliferation, apoptosis, or migration but also to immune cell function. Stromal-interaction molecules (STIM)-activated Orai channels are major Ca
entry channels in cancer cells and immune cells, they are upregulated in many tumors, and they are strongly regulated by ROS. Thus, STIM and Orai are interesting candidates to regulate cancer cell fate in the TME. In this review, we summarize the current knowledge about the function of ROS and STIM/Orai in cancer cells; discuss their interdependencies; and propose new hypotheses how TME, ROS, and Orai channels influence each other.