Fused Proteins Offer Hope for Treating the Most Malignant Cancers

BATON ROUGE -- An LSU researcher has discovered a potential treatment for the most malignant forms of cancer by fusing two proteins, one

that slips past the tumor’s defenses carrying a second protein to kill the tumor.

Both proteins are produced by bacteria. Staphylococcal Superantigen-Like protein 11 (SSL11) is the delivery platform. It carries a fragment of Pseudomonas exotoxin A (PE24) and binds to a tumor marker, Sialyl Lewis X (SLeX). PE24 turns off an enzyme (eukaryotic elongation factor 2 kinase) that aids tumor growth. The tumors die as a result.

“The more malignant the tumor is, the more likely it is to metastasize or spread. The greater the expression of SLeX, the shorter the person’s expected survival time, and the better the fit is for SSL11,” said LSU Assistant Professor of Biological Sciences Chen Chen. “The fused protein works in two stages, SSL binds to the tumor marker and prevents cancer cells from spreading. Then PE 24 kills the tumor cells.”

Chen said SSL11’s ability to halt the spread of cancer made her look at the immunotoxin as a delivery platform. By fusing SSL11 with PE24, Chen and her team created a treatment that works on a variety of cancers.

“We actually found it killed many different types of cancer cell lines in the lab, including lung, breast, colon and cervical cancer,” she said.

For now, Chen and her team are focusing on lung cancer. The disease kills 1.6 million people worldwide each year. Five-year survival rates range from 4-17%, depending on the stage when a person is diagnosed and the region where they live. Lung cancer cost the United States $23.8 billion in 2020.

The researchers recently won a National Institutes of Health R21 grant to further their research. Their next step will be to test the treatment on mice, and in the future seek funding or a partnership for clinical trials in people.

“Immunotoxin therapy is an exciting and promising addition to cancer treatment,” said Robert Twilley, LSU vice president of research and economic development. “Making sure Louisiana residents can access premier cancer care based on cutting-edge research is one of the top priorities of LSU’s Scholarship First Agenda, and Dr. Chen’s work demonstrates how our faculty are tackling this crucial health challenge.”

Chen worked with LSU’s Office of Innovation & Technology Transfer (ITC) on patenting her discovery.

“Our office helps faculty members like Dr. Chen protect and license their discoveries. We’re excited to explore the commercial possibilities for this cancer treatment,” said Daniel Felch, LSU ITC senior commercialization officer.

About LSU’s Office of Innovation & Technology Commercialization

LSU’s Office of Innovation & Technology Commercialization (ITC) protects and commercializes LSU’s intellectual property. The office focuses on transferring early-stage inventions and works into the marketplace for the greater benefit of society. ITC also handles federal invention reporting, which allows LSU to receive hundreds of millions of dollars each

year in federally funded research, and processes confidentiality agreements, material transfer agreements, and other agreements related to intellectual property.

About LSU Office of Innovation & Ecosystem Development

LSU Innovation unites the university’s innovation and commercialization resources under one office, maximizing LSU's impact on the intellectual, economic, and social development of Louisiana and beyond. LSU Innovation focuses on establishing, developing, and growing technology-based startup companies. LSU Innovation oversees LSU Innovation Park, a 200-acre business incubator that fosters early-stage tech companies, and the Office of Innovation & Technology Commercialization, which streamlines the process of evaluating, protecting, and licensing intellectual property created by LSU researchers. LSU Innovation serves as the host organization for the Louisiana Small Business Development Center (SBDC) Network which oversees all SBDC services across the state as well as the LSU SBDC, which provides free consulting services to small businesses across the state. LSU Innovation helps Louisiana technology companies apply for seed funding through the federal Small Business Innovation Research and Small Business Technology Transfer grant programs. LSU Innovation educates faculty, students, and the community on entrepreneurial principles through the National Science Foundation’s Innovation Corps (I-Corps) program which trains innovators to consider the market opportunities for pressing scientific questions, leading to increased funding state and federal grant programs as well as potential industry partners and licensees.