Microgravity and cancer cells: from molecular mechanisms to therapeutic strategies

All living organisms on Earth have evolved mechanisms to counteract the effects of gravity. In space, however, shear forces, buoyancy-driven convection, and hydrostatic pressure are either eliminated or significantly reduced. Microgravity disrupts the balance between intracellular structures and external forces, leading to changes at both the cellular and subcellular levels. The absence of gravitational forces in microgravity significantly impacts cellular behavior, including changes in tumor cell morphology, cytoskeletal structure, and gene expression. Research has demonstrated that microgravity induces the three-dimensional aggregation of cancer cells into multicellular spheroids, which more closely resemble in vivo tumors. These spheroids exhibit altered behaviors, including increased apoptosis, autophagy, and reduced proliferation and migration. Such changes suggest that microgravity may offer a promising novel therapeutic approach for cancer treatment. However, the precise underlying mechanisms remain largely unexplored. This review examines current microgravity research platforms and explores how microgravity affects tumor cell molecular and biological behaviors, offering valuable insights into the potential for innovative cancer therapies.