The PIK3CA gene provides instructions for making the p110 alpha protein, a subunit of the enzyme phosphatidylinositol 3-kinase (PI3K). This enzyme adds phosphate groups to other proteins, a process called phosphorylation. PI3K signaling is involved in various cell activities, including growth, division, movement, and survival. It also plays a role in producing new proteins and transporting materials within cells.
Understanding PIK3CA in Cancer
Mutations in the PIK3CA gene can lead to an altered p110 alpha subunit, causing PI3K to signal without proper regulation. This unregulated signaling contributes to uncontrolled cell proliferation, a hallmark of cancer. While PIK3CA mutations alone may not cause cancer, they are often found with mutations in other genes that influence cancer risk.
PIK3CA is one of the most frequently mutated genes in solid cancers. These mutations are common in types such as breast cancer (over 30%), endometrial cancer (over 30%), bladder cancer (over 20%), colorectal carcinoma (over 17%), and head and neck squamous cell carcinoma (over 15%). The mutations often cluster at specific “hotspot” sites, including glutamates at positions 542 and 545 in the helical domain, and histidine at position 1047 near the C-terminus of the kinase domain. These hotspot variants impact enzymatic activation and downstream biological responses, making PIK3CA a target for cancer research and therapeutic development.
PIK3CA Initiatives in Texas
Texas has become a center for PIK3CA-related cancer research, treatment, and clinical trials. Institutions across the state are involved in understanding PIK3CA mutations and developing targeted therapies. These efforts aim to improve outcomes for patients with PIK3CA-mutated cancers.
MD Anderson Cancer Center in Houston conducts extensive cancer research, including studies on PIK3CA. UT Southwestern Medical Center in Dallas and Baylor College of Medicine in Houston also contribute to these advancements. These centers offer access to novel treatments through clinical trials, providing patients with new therapies.
Texas Children’s Cancer and Hematology Center is conducting a Phase II multi-center study, EPIK-P2, assessing the efficacy and safety of alpelisib in pediatric and adult patients with PIK3CA-related overgrowth spectrum (PROS). This study, like others across Texas, advances precision medicine approaches for PIK3CA-driven conditions. Texas Oncology also participates in cancer research and clinical trials, contributing to cancer care across various locations, including Austin.