EDITORIAL COMMENT

In the Universe, four main forces are effective. These are weak nuclear force, strong nuclear force, electromagnetic force and gravitational force. Gravity is the attractive force between all matter. In space, the force of gravity is diminished, resulting in microgravity. Currently, there are various studies about microgravity and its effect on biological functions in the literature. In this review, the authors reported effects of microgravity on cancer culture studies. In these studies, some devices are used such as rotating wall vessel (RWV) bioreactor, clinostat, random positioning machine (RPM) (3D clinostat), and magnetic levitation. These 3D cell culture studies are focused on oncology. We can find some studies that especially focused on culture or co-culture of prostate cancer in the microgravity conditions. These authors suggested that effects of microgravity on the oncological cultures in the space station (10-4 and 10-6 g) were immune cell changes, alterations in gene expression, effects on cell signaling, effects on apoptosis, cytoskeletal changes, and alterations in cell shape. Microgravity environment of space includes lack of sedimentation, reduced fluid shear, cellular co-location and 3D multicellular growth. Microencapsulation technology was developed in like these conditions using a xenograft model of prostate cancer. Space presents an unlimited horizon for discovery. Microgravity can further our understanding of the fundamental role of gravity in cancer cell growth and function. These studies will expand our knowledge necessary for improving treatment options and exploring the etiopathogenesis of cancer.