Modeling and Therapeutic Targeting of p21-Activated Kinase Members in High-Risk Rhabdomyosarcoma
Rhabdomyosarcoma (RMS) is the most common tumor of the muscles affecting the pediatric population. RMS is highly aggressive and is classified by two subtypes, embryonal (ERMS) and alveolar (ARMS). Unfortunately, RMS has a high tendency to metastasize or to spread to different locations in the body. Despite aggressive treatments, patients with high-risk RMS still have a 5-year overall survival rate of only 20-30% highlighting the need for the new treatment options. Our lack of knowledge about the biology that contributes to metastasis limits the development of new treatment options for RMS. High-dose cytotoxic (cell-killing) chemotherapy and radiation are the current treatments for RMS and can have tremendous side effects in children such as damaging the heart and kidneys.
Therefore, we must gain insights into the critical changes occurring in the RMS cells that are contributing to tumor formation and aggressive metastatic disease in order to develop less toxic, targeted therapies. Targeted therapy exploits a feature unique to the tumor to kill it while traditional chemotherapy kills any rapidly dividing cell. To date, few actionable alterations have been identified for development of targeted therapies in RMS. In our studies of pediatric sarcomas, we have identified p21-activated kinases (PAKs) as key contributors to RMS cell survival and tumor cell spreading. PAKs are altered in many cancers and are attractive therapeutic targets for drug development. No prior studies have demonstrated the role for PAKs in RMS but our ongoing studies demonstrate PAKs as key mediator of RMS tumor progression.