SEP 22, 2017 02:45 PM PDT

Scientists Battle Cancer with the Poliovirus

WRITTEN BY: Xuan Pham
3 22 788

Samples of the modified poliovirus | Image: Duke University

With cancer putting up such strong fight, scientists are resorting to more unconventional therapies to give them the edge. The Zika virus was recently co-opted to fight deadly brain cancer, and now, scientists are turning their attention to the poliovirus.

The radical approach of using the poliovirus to kill cancer made big headlines in 2014. At that time, a group of researchers from Duke University reported that a lab-engineered hybrid virus was capable of killing cancer cells. The virus is a combination of the poliovirus and the rhinovirus, called PVS-RIPO. But while it showed promising results against cancer cells and was given to a limited number of patients as an experimental therapy, the team didn’t know the precise mechanisms behind how this virus worked.

"We have had a general understanding of how the modified poliovirus works, but not the mechanistic details at this level," said co-senior author and Duke neurosurgery professor Matthias Gromeier. "Knowing the steps that occur to generate an immune response will enable us to rationally decide whether and what other therapies make sense in combination with poliovirus to improve patient survival."

The same team persisted and recently published a follow up study, in which they detailed how the modified poliovirus unleashes its attack against cancer cells.

As it turns out, the modified poliovirus attaches to malignant cancer cells via the CD155 protein, which acts as a receptor for PVS-RIPO. Once bound, the virus kills the tumor cells, causing the release of tumor antigens. In the second phase of the attack, the modified virus infects two types of immune cells: dendritic cells and macrophages. This action triggers the immune system to attack viciously. Cancer-killing T-cells are launched to seek and destroy cancer cells lurking in the virus-infected tumor.

"Not only is poliovirus killing tumor cells, it is also infecting the antigen-presenting cells, which allows them to function in such a way that they can now raise a T-cell response that can recognize and infiltrate a tumor," says Smita Nair, the co-senior author on the study with Grimier. "This is an encouraging finding, because it means the poliovirus stimulates an innate inflammatory response."

The results were observed in human melanoma and breast cancer cell lines, and subsequently validated in mouse models. The team believes the same mechanism of attack could apply to several other cancer types that express the CD155 marker.

"Because PVSRIPO naturally targets and destroys cancer cells from most common cancer types (pancreas, prostate, lung, colon, and many others), it can be directed against these cancers as well," says Gromeier. "To establish this in the clinic, we plan future clinical trials in patients with cancers other than brain tumors."

PVS-RIPO earned the FDA’s “breakthrough therapy” designation last year, based on early success in clinical trials. If promising results continue, the treatment could be on the shortlist to receive approval.

Additional sources: Duke University, MNT

About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
APR 24, 2018
Cancer
APR 24, 2018
CAR-T Cell Therapy 101
Chimeric antigen receptor T cells (CAR-T cells) have emerged as a useful tool for cancer treatments in a small number of cancers thus far. This area of treatment research is expanding rapidl
MAY 10, 2018
Immunology
MAY 10, 2018
New Biomarker for Lung Cancer Diagnosis
Lung cancer is the most common cause of death from cancer for both genders and for people all over the globe. This is largely due to the lack of diagnostic
MAY 14, 2018
Clinical & Molecular DX
MAY 14, 2018
Early Differences Between Benign and Malignant Tumors
Physicians are in need of a dependable diagnostic approach for distinguishing between benign and malignant tumors early-on. Once doctors can rule out that
JUL 17, 2018
Cancer
JUL 17, 2018
Experimental "Trojan Horse" Tumor Destruction Approach Using CRISPR
CRISPR can be used to dupe circulating tumor cells into killing their own main tumor after "re-homing" back with a death receptor for tumor destruction.
JUL 23, 2018
Cancer
JUL 23, 2018
Increased Vitamin D Is Not Cancer Preventative
A new study in July's JAMA Oncology outlines the results of a 4-year study in New Zealand focused on vitamin D and if it is positively associated with cancer prevention.
JUL 25, 2018
Neuroscience
JUL 25, 2018
Can CT Scans Increase the Risk of Brain Cancer?
Medical imaging has gone from fuzzy X-rays that didn't show much, to real-time functional MRI scans in just a few decades. Being able to see inside the
Loading Comments...