Dual gene therapy suppresses lung cancer in preclinical test

January 15, 2007

HOUSTON -- Combination gene therapy delivered in lipid-based nanoparticles drastically reduces the number and size of human non-small cell lung cancer tumors in mice, researchers at The University of Texas M. D. Anderson Cancer Center and the University of Texas Southwestern Medical Center report in the Jan. 15 edition of Cancer Research.

Two tumor-suppressing genes given intravenously reduced cancer separately but had their most powerful effect when administered together, cutting the number of tumors per mouse by 75 percent and the weight of tumors by 80 percent.

"In cancer treatment we have combination chemotherapy, and we also combine different modes of therapy - surgery, radiation and chemotherapy. Now you've got the possibility of combined targeted gene therapy," said Jack Roth, M.D., professor and chair of the M. D. Anderson Department of Thoracic and Cardiovascular Surgery and a senior researcher on the project.

The genes wrapped in the nanoparticles were p53, a well-known tumor suppressor that works by causing defective cells to commit suicide and is often shut down or defective in cancer cells, and FUS1, a tumor-suppressor discovered by the research group that is deficient in most human lung cancers. Each nanoparticle carried one of the two genes.

The Cancer Research paper reports that FUS1 works with p53 to force the lung cancer cells to kill themselves - a process known as apoptosis.

Further analysis showed that the combination achieved greater cell suicide because FUS1 suppresses a gene that expresses a protein known to rapidly degrade p53, says senior author Lin Ji, Ph.D., M. D. Anderson associate professor of thoracic and cardiovascular surgery.

The FUS1/p53 combination also activates a cell suicide pathway based in the cells' mitochondria, their energy powerhouse.

Lab experiments first showed that the gene combination cut the number of viable cells in four lines of human non-small cell lung cancer by 70 to 80 percent 48 hours after treatment while leaving a control group of normal cells unaffected. The cancer cell lines treated with the gene combination had 2 to 3 times more cells killed by apoptosis than either gene nanoparticle had individually. The research team then confirmed these findings in the mouse studies.

The nanoparticle delivery system, which the researchers have used for years, consists of a plasmid gene expression cassette loaded with DNA that encodes either the p53 or the FUS1 protein. This is wrapped tightly in a form of cholesterol to protect it from the body's defense mechanisms. "You can't deliver naked DNA for cancer therapy," Ji says.

The nanoparticles accumulate mainly in the lungs, particularly in the tumors, Ji says. The positively charged nanoparticles are delivered to the negatively charged cancer cell membrane and taken into the cell, where the genes repeatedly express either p53 or FUS1 tumor-suppressing proteins.

Roth expects the research team to advance combination therapies to clinical trials in the coming years, either of genes or of genes with other biologic or chemotherapy agents.

"We certainly hope this approach will be more effective but we also think it's likely to be much less toxic, with fewer side effects, than other types of combined cancer therapy," Roth says. "These genes don't have much effect on normal tissue or normal cells when they are overexpressed. It's really just cancer cells where they seem to have their effect. Ultimately, the usefulness of this approach has to be proven in clinical trials."
-end-
EMBARGOED FOR RELEASE UNTIL 12:01 A.M. (EST), MONDAY, JANUARY 15, 2007

The FUS1 nanoparticles are being tested alone in a phase 1 safety and dose-escalation clinical trial at M. D. Anderson for patients with advanced non-small cell lung cancer that has spread to other organs. Charles Lu, M.D., associate professor in the M. D. Anderson Department of Thoracic, Head and Neck Medical Oncology, is conducting the clinical trial, which is funded by M. D. Anderson's and UT-Southwestern's joint National Cancer Institute Specialized Program of Research Excellence (SPORE) in lung cancer.

Co-authors with Roth and Ji are John D. Minna, M.D., Department of Internal Medicine and Pharmacology, Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center; first author Wu-Guo Deng, Ph.D., Hiroyaki Kawashima, M.D., Ph.D., Guanglin Wu, M.D., Gitanjali Jayachandran, Ph.D., and Kai Xu, M.S., all of the M. D. Anderson Department of Thoracic and Cardiovascular Surgery.

Research was supported by a National Cancer Institute SPORE grant, U.S. Department of Defense TARGET Lung Cancer Programs grant, W.M. Keck Gene Therapy Career Development grant, M. D. Anderson's Cancer Center Support Grant, and a grant from the Tobacco Settlement Funds appropriated by the Texas Legislature.

University of Texas M. D. Anderson Cancer Center

Related Cancer Cells Articles from Brightsurf:

Cancer researchers train white blood cells to attacks tumor cells
Scientists at the National Center for Tumor Diseases Dresden (NCT/UCC) and Dresden University Medicine, together with an international team of researchers, were able to demonstrate that certain white blood cells, so-called neutrophil granulocytes, can potentially - after completing a special training program -- be utilized for the treatment of tumors.

New way to target some rapidly dividing cancer cells, leaving healthy cells unharmed
Scientists at Johns Hopkins Medicine and the University of Oxford say they have found a new way to kill some multiplying human breast cancer cells by selectively attacking the core of their cell division machinery.

Breast cancer cells use message-carrying vesicles to send oncogenic stimuli to normal cells
According to a Wistar study, breast cancer cells starved for oxygen send out messages that induce oncogenic changes in surrounding normal epithelial cells.

Breast cancer cells turn killer immune cells into allies
Researchers at Johns Hopkins University School of Medicine have discovered that breast cancer cells can alter the function of immune cells known as Natural killer (NK) cells so that instead of killing the cancer cells, they facilitate their spread to other parts of the body.

Breast cancer cells can reprogram immune cells to assist in metastasis
Johns Hopkins Kimmel Cancer Center investigators report they have uncovered a new mechanism by which invasive breast cancer cells evade the immune system to metastasize, or spread, to other areas of the body.

Engineered immune cells recognize, attack human and mouse solid-tumor cancer cells
CAR-T therapy has been used successfully in patients with blood cancers such as lymphoma and leukemia.

Drug that keeps surface receptors on cancer cells makes them more visible to immune cells
A drug that is already clinically available for the treatment of nausea and psychosis, called prochlorperazine (PCZ), inhibits the internalization of receptors on the surface of tumor cells, thereby increasing the ability of anticancer antibodies to bind to the receptors and mount more effective immune responses.

Engineered bone marrow cells slow growth of prostate and pancreatic cancer cells
In experiments with mice, researchers at the Johns Hopkins Kimmel Cancer Center say they have slowed the growth of transplanted human prostate and pancreatic cancer cells by introducing bone marrow cells with a specific gene deletion to induce a novel immune response.

First phase i clinical trial of CRISPR-edited cells for cancer shows cells safe and durable
Following the first US test of CRISPR gene editing in patients with advanced cancer, researchers report these patients experienced no negative side effects and that the engineered T cells persisted in their bodies -- for months.

Zika virus' key into brain cells ID'd, leveraged to block infection and kill cancer cells
Two different UC San Diego research teams identified the same molecule -- αvβ5 integrin -- as Zika virus' key to brain cell entry.

Read More: Cancer Cells News and Cancer Cells 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.