Mesothelin engineered on virus-like particles provides treatment clues for pancreatic cancer

February 15, 2008

New understanding of a protein that spurs the growth of pancreatic cancer could lead to a new vaccine against the deadly disease, said researchers at Baylor College of Medicine in Houston in a report appearing in the current edition of the journal Molecular Cancer Therapeutics.

The protein called mesothelin appears to play an important role in promoting pancreatic cancer growth, said the senior author Dr. Qizhi (Cathy) Yao, professor of surgery - vascular surgery at BCM. She, along with co-lead authors Dr. Min Li, assistant professor of surgery, and research associate Dr. Uddalak Bharadwaj carried out the studies of the protein that is found on the tumor cells' surface.

"Mesothelin is found in other cancers for several years," said Yao, also a researcher in the Dan L. Duncan Cancer Center at BCM. "However, we didn't know the role it played in pancreatic cancer:" until she and her colleagues reported in this article. In fact, they found very high levels of mesothelin in 18 of 21 samples of patient's pancreatic tissues compared to amounts found in nearby normal tissues. In studies of this protein in the lab, pancreatic cancer cell lines that produced high levels of mesothelin grew faster and spread more than those in which mesothelin levels were lower.

Pancreatic cancer cells grew and spread faster in mice whose tumors expressed high levels of mesothelin than in those whose cancer did not, said the researchers, who conducted the studies in an immune deficient mouse.

"We saw this molecule as very significant in the life of the tumor cells," Yao said. "Our next step is to identify whether this would be a good active immunotherapy target."

Making a treatment vaccine of virus-like particles (VLPs) that contained mesothelin, researchers injected mice having pancreatic cancer with this vaccine three times. Virus-like particles have the unique property of inducing protective immune responses but they lack the infectious capacities of the original virus.

Tumor growth in the immunized mice slowed and in some cases the tumor disappeared. The average life span for the mice not treated was four weeks. The immunized mice survived five weeks longer than those not treated.

Researchers found that the immunization works by suppressing production of key immune system cells that suppress the body's ability to fight the tumor. The researchers said pancreatic cancers produce these cells, called T regulatory cells, as a protective measure.

"If we are able to see the same results in humans, this would allow us to incorporate a combination therapy to treat the tumor," Yao said. "Treatment with a single drug is not effective."

Yao and her colleagues are seeking U.S. Food and Drug Administration approval to begin studies using their vaccination on people suffering from pancreatic cancer.
-end-
Other BCM researchers who took part in the study include Drs. Rongxin Zhang, Sheng Zhang, Hong Mu, William Fisher, F. Charles Brunicardi, and Changyi Chen.

Funding for the study came from grants from the National Institutes of Health, the Dan L. Duncan Cancer Center at BCM and the American Cancer Society. The article is available at http://mct.aacrjournals.org/

Baylor College of Medicine

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.