Engineering an “Invisible Cloak” for Bacteria to Deliver Cancer Drugs

Scientists exploring a novel but highly promising avenue of cancer treatment have developed a type of “invisibility cloak” that helps engineered bacteria sneak through the body’s immune defenses. The result is more powerful delivery of anti-cancer drugs and shrinking of tumors in mice, with the scientists hopeful the approach can overcome toxicity issues that have plagued these techniques so far.

Traditional forms of cancer treatment – radiotherapy, chemotherapy and immunotherapy – each have their own strengths when it comes to combating tumors, and what’s known as therapeutic bacteria could bring its own set of skills into the mix. Bacteria itself can have powerful anti-tumor effects, but genetic engineering could allow it to take on entirely new capabilities, including releasing specific compounds or carrying potent anti-cancer drugs. There are a number of challenges in using bacteria for this purpose, however, with the issue of toxicity chief among them. Living bacteria can grow rapidly in the body, and because the body’s immune system sees them as a threat, too many can trigger an extreme inflammatory response.

In clinical trials, these toxicities have been shown to be the critical problem, limiting the amount we can dose bacteria and compromising efficacy,” said Columbia University‘s Jaeseung Hahn, who co-led the research. “Some trials had to be terminated due to severe toxicity.

Addressing this toxicity problem would mean finding (or engineering) bacteria that can evade the body’s immune system and safely make it to a tumor to fulfill their anti-cancer potential. Hahn’s team has made new inroads in this space by turning to sugar polymers called capsular polysaccharides (CAP), which naturally coat bacterial surfaces and protect them from immune attacks.

We hijacked the CAP system of a probiotic E. coli strain Nissle 1917,” said Tetsuhiro Harimoto, the study’s co-lead author. “With CAP, these bacteria can temporarily evade immune attack; without CAP, they lose their encapsulation protection and can be cleared out in the body. So we decided to try to build an effective on/off switch.”

Source: https://www.engineering.columbia.edu/

New Vaccine to Ward off Cancer Permanently

A Merseyside man has become the first in the UK to receive a ‘vaccine’ that is hoped will stop his recurring head and neck cancer from returning, in a clinical research trial which may help bring further ground-breaking treatments for the disease. The clinical research team at The Clatterbridge Cancer Centre has given patient Graham Booth an injection of a therapy tailor-made to his personal DNA and designed to help his own immune system ward off cancer permanently.

Graham first had head and neck cancer in 2011 and it then returned four times, each time meaning he needed gruelling treatment, including facial surgery, reconstruction and radiotherapy. He is now hoping this new treatment – part of the Transgene clinical research study – will mean it does not come back. Dad-of-five Graham, 54, will have a year-long course of immunotherapy injections in a bid to keep him cancer-free, part of a research project designed to reduce deaths and recurrence in head and neck cancers, including of the throat, neck, mouth and tongue. Graham, of West Kirkby, said he was not worried about being the first person in the UK to receive this pioneering treatment and that it “opened new doorways” which gave him hope that the cancer would not come back.

When I had my first cancer treatment in 2011, I was under the impression that the cancer would not return. My biggest fear was realised in 2016 when it came back and then in 2019 and then two cases in 2021,” explains Graham. “Last year I had the feeling of the cancer progressing and there were not a lot of options left. This clinical trial has opened new doorways and gives me a bit of hope that my cancer won’t come back.”

And this could open doorways for other people. I’m hopefully looking at a brighter future. A bit of hope that it never returns again – which would mean the world to my family and everyone around me.”

Source: https://www.cityam.com/