Nav: Home

Tightening the tumor-targeting abilities of checkpoint blockade immunotherapy

July 12, 2019

Seeking to improve upon existing checkpoint inhibitor therapies, scientists have developed a common checkpoint inhibitor (anti-PD-L1) in a nanoparticle formulation, which were activated specifically at tumor sites in mouse models of cancer. Their approach intends to prevent the immune system from becoming tolerant of tumors - which occurs in 30% of all cancer patients - and could help avoid the toxic off-target effects observed during the use of standard antibody checkpoint inhibitors. As well, the antibodies used to target immune system-suppressing proteins like PD-1 and PD-L1 can fail to reach deep-seated or metastatic tumors, further hindering their efficacy. Seeking a method to overcome these hurdles, Dangge Wang and colleagues developed highly tumor-specific nanoparticles carrying PD-L1-targeting antibodies and a photosensitizer, a light-activated molecule that produces tumor-killing reactive oxygen species after encountering matrix metalloproteinase protein 2 (MMP-2), a protein abundant in tumors. In mouse models, the dual administration of PD-L1-carrying nanoparticles in conjunction with local near-infrared radiation (that activates the photosensitizer) promoted the infiltration of cancer cell-killing T cells into the tumor site and further sensitized the tumors to PD-L1 checkpoint blockade. This combination also helped the nanoparticles effectively suppress tumor growth and metastasis to the lung and lymph nodes, resulting in approximately 80% mouse survival over 70 days, compared to complete mouse death in 45 days in the group treated with only PD-L1 antibodies. With further improvement, the platform used here could be readily adapted to other immune checkpoint inhibitors for improved checkpoint blockade immunotherapy, the authors say.
-end-


American Association for the Advancement of Science

Related Cancer Articles:

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.
More Cancer News and Cancer Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...