Joyce Schroeder: A new way to fight cancer

Up close, a thin slice of a human cell wall might look like the Great Wall of China, with an array of towers, tubes and molecular mailboxes.

Getting a message through is tricky. The molecule must hit the right receptor, a kind of smart mailbox that regulates life, screening messages, letting only a few bind to the cell.

The right signal can help sustain proper growth. But at another time in an organism's development, the same signal, coming down the same pathway, can promote unregulated, toxic growth, or overexpression, in genetic terms, leading to a tumor.

At the UA's Arizona Cancer Center, Joyce Schroeder is developing innovative ways to fight breast cancer by studying how to let the right messages get through at just the right time. Schroeder, a BIO5 member and associate professor of molecular and cellular biology in the College of Science at the UA, says her lab works on the basic biology of breast cancer as it also develops a drug to disrupt growth in tumor cells, without disrupting the life-sustaining signals.

The drug she has invented works on a type of mailbox with a very big label, epidermal growth factor receptor, or EGFR. The EGFR family of proteins makes up a crucial aspect of oncology because it signals not only growth but disregulated growth, or, often, cancer.

The peptide-based drug Schroeder has developed, still in preclinical stages, will inhibit those wrong messages. 'It's brand new,' she said. 'It takes a unique point of view. It will shut down the cancer-specific activities that happen as a tumor metastasizes, or goes crawling around. That is what causes a patient's death.' The peptide will put a stop to that unruly behavior by getting the colliding, disorderly proteins to back off from each other and settle down.

That aspect of her work is part of BIO5's Drug Discovery and Development Initiative.

Her lab uses transgenic mouse models of cancer to study how a tumor develops and spreads. She employs experts in genetics, cancer biology and molecular biology. 'We have to look at a cell, pull apart its tiny processes and understand what's going on,' she says, 'then take the right tools from molecular biology and apply them to cancer biology.'

Schroeder, born in Phoenix, studied microbiology at the UA before starting doctorate work at the University of North Carolina Chapel Hill. There in 1992, a new breast cancer project was rolling out as she arrived. 'My slice was to work on transgenic mouse models, getting at which genes cause breast cancer,' she recalls. 'The same genes that otherwise do good work are screwed up in human cancer.'

Since 2002 she has worked at the Arizona Cancer Center and BIO5 on questions that link up human development and cancer. At an early stage in life, any organism needs to shut down certain pathways inside its cells, and keep them at OFF, to survive. At times the organism turns a development pathway back to ON, when it's not supposed to,' she says. That can be linked to genetic mutations, Schroeder says.

More about Dr. Schroeder

The UA College of Science named Joyce Schroeder a 2008 Galileo Circle Fellow, one of its highest faculty honors. Her lab at the Cancer Center is funded by grants from the National Cancer Institute, the Arizona Biomedical Research Commission and the Ginny Clements Breast Cancer Foundation. Students in her lab are funded through fellowships administered at the Department of Defense's Breast Cancer Research Program. Before joining the UA in 2002, she had a post-doctoral fellowship at the Mayo Clinic in Scottsdale.