Engineering the Environment of Oral Cancer
New $3.05 million NIDCR R01 supports Dr. Ricardo Cruz-Acuña’s research into the physical forces that may drive precancerous oral lesions toward cancer
When oral cancer is not caught early, the consequences can be life-altering. As tumors of the tongue and other parts of the mouth become more extensive, treatment may involve removing significant amounts of tissue, leaving patients struggling with speech or swallowing. Survival also declines dramatically once the disease has spread. When the disease is still localized, nearly 89 percent of patients are alive five years after diagnosis. Once it has spread to distant parts of the body, that figure falls to 36 percent.
Oral cancer, however, can be preceded by visible precancerous lesions. These lesions provide an opportunity to study the changes that occur before cancer becomes invasive and better understand what may drive that progression.
With a new $3.05 million, five-year R01 grant from the National Institute of Dental and Craniofacial Research, Dr. Ricardo Cruz-Acuña, PhD, assistant professor of cancer engineering at Columbia University College of Dental Medicine and a member of the Tumor Biology and Microenvironment Program at the Herbert Irving Comprehensive Cancer Center, is investigating what happens during that critical period before cancer develops. His research focuses on whether changes in the physical environment surrounding precancerous cells may help push them toward cancer, looking beyond genetic changes in the cells themselves.
Understanding what drives that progression could help address a persistent clinical challenge: not every precancerous lesion follows the same course. Some will eventually become cancer, while most will not. When an oral surgeon identifies suspicious tissue, it may be biopsied and then monitored over time for changes. Pathologists can assess the degree of abnormality in the tissue, which provides important information about risk, but they cannot determine with certainty what an individual lesion will ultimately do.
Cruz-Acuña’s hypothesis is that the cells themselves are only part of the story. The physical properties of the tissue surrounding them may also play a role in whether a precancerous lesion progresses. Two properties matter in particular: stiffness, or how firmly the tissue pushes back when it is pressed, and viscosity, or how readily it flows and relaxes under that pressure. Both change as a lesion advances.
“It’s not only genetics,” Cruz-Acuña said. “We believe the physical properties of the tissue surrounding those cells also contribute to disease progression, and we want to test whether changes like increased stiffness and viscosity are actually driving the transformation into cancer cells.”
To test that idea in the lab, Cruz-Acuña’s team grows cells obtained from patient biopsies as organoids, three-dimensional structures that more closely reproduce the characteristics of the original tissue than cells grown flat in a traditional Petri dish. The organoids are suspended within an engineered hydrogel, allowing the cells to grow in three dimensions within an environment that more closely resembles the one they encounter in the body.
Patient-derived organoids grown from a precancerous oral lesion inside the lab's engineered hydrogels. At left, stained to show structure; at right, imaged by fluorescence microscopy, with CD44 in green and cell nuclei in blue. Each is a fraction of a millimeter across. Image: Esha Uddin, Cruz-Acuña Lab. Scale bar, 100 µm.
What makes the system distinctive is how precisely that environment can be manipulated. The researchers designed the hydrogel using mechanical measurements from biopsies of normal oral tissue, precancerous lesions and cancerous lesions, where they observed increasing stiffness and viscosity as disease progressed. Within the hydrogel, however, they can control those properties independently. By changing stiffness and viscosity separately, the researchers can isolate how each one affects the behavior of precancerous cells.
The researchers will then look at how the precancerous cells respond, both functionally and at the molecular level. Much of that attention is on a single protein, CD44, which sits on the surface of the cell and binds to the matrix around it. Cruz-Acuña’s team suspects CD44 acts as a kind of antenna, converting the physical state of the tissue into chemical signals inside the cell, and that stiffness and viscosity switch on different programs through that same receptor.
By identifying molecular changes associated with the cells’ response to stiffness and viscosity, Cruz-Acuña hopes the work will also point toward markers that could eventually help distinguish lesions at higher risk of progressing to cancer from those at lower risk. Such markers could provide another layer of information beyond what clinicians can currently learn from examining the tissue itself.
The grant also funds a direct test of whether that signaling can be interrupted. The team will treat organoids with compounds that block CD44 and the pathways it activates. The work is preclinical, and any therapy for patients remains far off, but the experiments are designed to show whether the pathway is one worth pursuing.
The study could ultimately go beyond identifying which lesions are most likely to progress. By tracing how precancerous cells respond to their physical surroundings, Cruz-Acuña and his team hope to uncover potential opportunities for earlier intervention.
“We want to test whether those physical changes are actually driving the transformation into cancer cells, and then whether we can block those,” Cruz-Acuña said.
The R01 also marks a new direction for Cruz-Acuña’s research program. His previous work has focused largely on esophageal cancer, while the five-year award expands his lab’s work into oral cancer and builds on his broader interest in understanding how the environments surrounding cells contribute to disease.
The project also draws on expertise across Columbia, bringing together researchers from CDM and the Herbert Irving Comprehensive Cancer Center. As principal investigator, Cruz-Acuña assembled a team whose expertise spans different parts of the research, from the study of patient-derived organoids to the clinical understanding of oral disease. The team includes Dr. Sidney Eisig, director of Oral and Maxillofacial Surgery; oral pathologist Dr. Elizabeth Philipone, now professor of Diagnostic Sciences at Rutgers School of Dental Medicine and formerly a faculty member at CDM; and Dr. Hiroshi Nakagawa, professor of Medicine and a cancer biologist at Columbia’s Herbert Irving Comprehensive Cancer Center. The collaboration also gives the project access to research facilities and expertise across both units.
For now, the work begins with understanding what pushes a precancerous lesion toward cancer, but Cruz-Acuña hopes its implications will eventually reach much further.
"The window that matters is the one before anyone needs surgery on their mouth,” Cruz-Acuña said. “If we can learn what pushes a lesion across that line, that’s where we have a chance to intervene.”