The tumors growing like tiny backpacks on a batch of mice come from human cancer patients just across campus at University of Colorado Hospital.
Within an hour of surgery, a team led by head-and-neck-cancer hotshot Dr. Antonio Jimeno can place a tumor onto the back of a mouse in the school's underground animal- research lab.
The tumor grows, and a few months later, there is enough of it to put into 20 to 40 mice, their tiny bodies used to test the ability of hundreds of drugs to kill cancer cells.
Sometimes, doctors are able to determine the course of treatment for a patient based on which drug is shrinking their tumor in a rodent counterpart. But the goal of the research is much broader: to discover the specific combination of abnormal genes that causes head and neck cancer, and which drugs will stifle it.
"We create a pseudo-patient," said Jimeno, a 36-year-old Spaniard who was lured from Johns Hopkins University in Baltimore to direct CU's head-and-neck-cancer department 2 1/2 years ago.
Most researchers across the country seeking a cure for head and neck cancer grow cell lines in a plastic dish and, when they are large enough to form a tumor, put them into mice. By using a "fresh cancer sample" directly from human to mouse, scientists get a closer idea of how the tumor would grow in a human body, Jimeno said.
His research uses fewer mice than traditional experiments because human tumors are more predictable when they are directly transferred, skipping the petri dish, Jimeno said. Each mouse — genetically engineered to have no immune suppression and therefore not reject the tumor — costs $40 to $50.
Entering the lab where the mice live requires about six weeks of vaccinations and training, plus an astronautlike suit to prevent germs from killing the mice. The tumors, Jimeno said, are implanted without pain and by federal rules cannot grow to more than 10 percent of a mouse's body weight.
They are removed when they reach the size of a chickpea.
Jimeno's team has taken tumors in the past year from 35 patients with head and neck cancer, which attacks the mouth, throat and voice box. Among them was Ken McConnellogue, CU's vice president for university relations.
A lump in his neck
McConnellogue was diagnosed with cancer at the CU medical campus in Aurora after feeling a lump on the side of his neck last fall.
During a doctor's appointment, Jimeno asked whether McConnellogue would mind if researchers took the tumor from his tonsil and gave it to some mice.
"Patients from all walks of life understand — 'You are testing drugs in mice, and when you find out which one works, you will give it to me. Then you won't have to test them all on me,' " Jimeno said.
McConnellogue, who learned last month his cancer was gone and then boarded a plane to Hawaii, benefited from a cutting-edge chemotherapy and radiation treatment — one tested during scientific experiments just a few years ago and approved for use on humans.
"This is how the system should work," he said. "I'm happy my case was part of a knowledge base that will help others. It will allow much more precision in the selection of drugs and treatment for people."
If McConnellogue were to relapse, it's possible CU researchers could determine what drugs to give him based on what worked best in the mice carrying his tumor. The researchers are testing combinations of already-approved drugs as well as new, unapproved drugs to determine whether they should be used in clinical trials on humans.
About 45,000 people are diagnosed with head and neck cancer each year in the United States, and about 15,000 die from the disease. The cancer is linked to tobacco use and, more recently, to the human papillomavirus — the same infection considered the major cause of cervical cancer in women.
HPV percentage to grow
About one quarter of head-and- neck-cancer cases today are linked to HPV, and doctors expect that percentage to grow to about half of all cases by 2020.
Few researchers are able to implant fresh head-and-neck tumors directly into animals, in part because of the high potential for infection, said Dr. Christine Chung, a cancer scientist and professor at Vanderbilt University. Tumors removed from the mouth and throat often are contaminated by bacteria and fungi, she said.
But when researchers can pull off a direct transfer, they are able to "simulate closer to what a tumor would act like" in a human. A plastic dish, in contrast, is a flat surface void of normal cells — just a tumor growing on its own, Chung said.
Still, there are limitations to studying cancer in mice instead of humans. Research mice are genetically uniform and live in cages void of variety in diet or environment.
"But you cannot implant tumors into a bunch of humans and give them chemo drugs," Chang said.
Jimeno's research is funded by a $275,000 U.S. Department of Defense grant and a $300,000 grant from the National Institutes of Health.
Jennifer Brown: 303-954-1593 or email@example.com