Dr. Qingyun LiuMore than 100,000 people in the United States will be diagnosed with colorectal cancer this year. While the incidence of this cancer is dropping in the elderly, colon cancer rates are rising among those under 54 years of age.

Qingyun (Jim) Liu, PhD, director, of the IMM’s Center for Translational Cancer Research, and his lab have dedicated years of research to better understand colon cancer and develop potential therapeutics.

“I have been working on colon cancer since I discovered a group of receptors long before I joined UTHealth Houston,” Liu said, adding that this group of receptors has been key to understanding colorectal cancer.

Prior to joining the IMM in 2009, Liu worked 16 years in the drug discovery industry.
Taking a molecular and cellular approach, Liu and his lab are working to discover why colon cancer produces these receptors and how they work within cancer cells.

“We will then be able to develop potential drugs that target these receptors on the cancer cells,” he explained.

Using an approach called antibody drug conjugate (ADC) – whereby the antibody attached with a toxin binds directly to the cancer cell receptor, researchers target points of interest.
“This is like a smart bomb because it targets specific kinds of cells,” he explained, adding that ADC has become successful in treating blood, bladder, breast, and uterine cancers.

The lab has published research on new ADCs for colon cancer and is funded by the National Institutes of Health and the Cancer Prevention and Research Institute of Texas.

“These grants allow us to engineer different antibodies to target these receptors,” Liu said. “We are trying to optimize and broaden our testing, including safety research.”

The lab is also using a ligand-based drug conjugate approach to attack colon cancer cells.

“These receptors bind molecules called the ligand, which is basically the signaling-triggering molecule of these receptors,” Liu explained. “We came up with a clever approach to put a cytotoxin onto the ligand. The trick is, we actually created a ligand that is not active anymore.”

Liu and colleagues modified the ligand so that it becomes inactive but still binds to the receptors very strongly. “It will still target the receptors without doing anything but carrying the drug,” Liu said.

“So far, the results are very promising,” Liu added. “We are working to ensure this approach can be tolerated at a therapeutically effective dose without causing severe side effects.”
Other work of the center includes investigating how cancer cells develop drug resistance and how they metastasize.

“We are also using lighting and imaging to track how drugs enter a tumor and visualize how the tumors develop,” he said.

To further understand cancer, the center takes cancer cells from patients and grows them into a three-dimensional model in a petri dish.

“Since tumors are three-dimensional, this is more like a real tumor,” Liu said. “We can then conduct our experiments in these tumors and see how they will respond to different treatments.”