SOX17 is a protein that plays a significant role in various biological processes. It functions as a transcription factor, acting like a master switch within cells, turning specific genes on or off. This precise control directs a cell’s development and function. SOX17 belongs to the SOX (SRY-related HMG-box) family of proteins, recognized for their regulatory roles in embryonic development.
Role in Embryonic Development
SOX17 guides the formation of several basic body structures during early embryonic development. It is particularly recognized for its role in establishing the definitive endoderm, one of the three primary germ layers in the embryo. These germ layers are foundational blueprints, each giving rise to distinct tissues and organs throughout the body.
The definitive endoderm, largely dependent on SOX17, develops into the linings of the digestive and respiratory systems, and solid organs such as the liver and pancreas. Without proper SOX17 function, these internal structures would not form correctly.
Beyond its role in internal organ development, SOX17 is also involved in building the body’s vascular system. It is recognized for its contribution to both vasculogenesis, the initial formation of new blood vessels from scratch, and angiogenesis, the growth of new blood vessels from existing ones. Without adequate SOX17 activity, proper blood vessel networks cannot form, which is necessary for supplying nutrients and oxygen to the developing embryo, thus supporting its growth and survival. SOX17 also plays a role in the normal looping of the embryonic heart tube.
Function in Adult Tissues and Stem Cells
SOX17 continues to play a role in adults, contributing to the maintenance of the vascular system. It is involved in postnatal angiogenesis, the formation of new blood vessels from existing ones after birth. This ongoing process helps repair and maintain blood vessel health.
Research focuses on SOX17’s utility in the laboratory, particularly with stem cells. Scientists use SOX17 as a tool to direct the fate of pluripotent stem cells, which are capable of developing into nearly any cell type in the body. Introducing SOX17 guides these versatile cells towards becoming endoderm-derived cells. This capability is a foundational step for creating specific organ cells, such as those of the liver or pancreas, in a laboratory dish for research or therapeutic purposes.
Connection to Human Diseases
When SOX17 does not function correctly, due to genetic mutations or abnormal protein levels, it can contribute to various human diseases. Dysregulation, meaning the protein is expressed at wrong levels or in inappropriate tissues, can lead to health problems.
Problems with SOX17 can manifest as developmental disorders. For instance, mutations in the SOX17 gene have been linked to certain vascular malformations, where blood vessels do not form or connect properly. It is also associated with vesicoureteral reflux (VUR), a condition where urine flows backward from the bladder to the kidneys, which can lead to kidney damage. These examples illustrate how disruptions in SOX17’s early developmental roles can lead to lasting health issues.
SOX17 exhibits a complex and often paradoxical role in cancer. In some cancers, such as certain types of colorectal cancer, SOX17 acts as a tumor suppressor, meaning that the loss or reduction of SOX17 activity can contribute to the growth and progression of the tumor. Conversely, in other cancers, including certain ovarian and lung cancers, SOX17 can behave as an oncogene, where its presence or increased activity promotes cancer growth. This dual nature highlights the intricate ways SOX17 interacts with different cellular environments and signaling pathways in various cancer types.
Applications in Medical Research
Understanding SOX17’s functions is leading to promising applications in medical research. These applications span regenerative medicine and cancer therapeutics.
In regenerative medicine, SOX17 is being explored for its ability to guide stem cell differentiation. Building on its role in directing endoderm formation, scientists are investigating how SOX17 can help coax pluripotent stem cells to become specific cell types, such as insulin-producing pancreatic beta cells. This research holds potential for developing new cell-based therapies for conditions like diabetes.
SOX17’s involvement in various cancers makes it a subject of interest for cancer therapeutics. Because SOX17 can act as either a tumor suppressor or an oncogene depending on the cancer type, researchers are studying it as a potential target for new cancer drugs. Additionally, SOX17 expression levels or methylation patterns are being investigated as biomarkers, which could help predict a patient’s prognosis or their response to specific treatments.