Microorganisms residing in the gut may stimulate the immune system to launch an assault against cancer cells.
Title: Unveiling the Gut-Immune Connection: Bacteria that Bolster the War Against Cancer
Hey there! Turns out, there's a gang of gut bacteria out there that can give your immune system a much-needed boost in its fight against cancer. This groundbreaking discovery, published in Nature Communications, promises to reshape and personalize immunotherapy treatments for the little devils we call cancer cells.
You know what they say — immunotherapy is all about empowering the body's internal defense system to vanquish disease. One method employs drugs known as immune checkpoint inhibitors. These bad boys block proteins cancer cells produce, protections that generally keep them safe from immune cell attacks.
But here's the kicker: It's not everyone who responds to cancer treatment using these immune checkpoint inhibitors, and the drugs can cause some serious side effects. So, what gives?
Enter the international research team led by the Sanford Burnham Prebys Medical Discovery Institute, based in sunny La Jolla, California. In a nutshell, they identified 11 gut bacteria strains that had a hand in slowing down the growth of melanoma tumors in mice.
Moreover, they flagged a significant pathway known as Unfolded Protein Response (UPR) as a major link connecting gut bacteria and the immune system's antitumor abilities. UPR is like the beneficial nitro-boost for the immune system's protein factory, ensuring proteins remain stable and healthy even under stress.
The crew found that UPR activity was lower in people with melanoma whose cancers responded well to immune checkpoint inhibitors, suggesting UPR activity could be a potential marker helping identify those with melanoma more likely to respond positively to treatment with these immune checkpoint inhibitors.
"These findings," says Ze'ev Ronai, the study's senior author and a professor at Sanford Burnham Prebys, "identify a group of beneficial gut bacteria strains and biomarkers that could help personalize immunotherapy for melanoma patients."
A Need for Improved Immunotherapy
Though it's relatively rare, melanoma is notorious for its rapid cell division, ability to invade nearby tissue, and potential to spread to other parts of the body. As such, it poses a significant and potentially life-threatening threat. Being responsible for most skin cancer deaths in the United States, melanoma claimed around 7,230 lives during 2019.
The good news is that treatment with immune checkpoint inhibitors has shown promising results, drastically improving survival rates for those battling melanoma. However, even when paired with other treatments, these therapies only work effectively for about half the cases. Plus, patients may still suffer from autoimmune reactions, limited response duration, and even resistance to the treatment.
The recent study further highlights the interplay between gut microbes and immunotherapy efficacy. Previous research has proven that certain gut bacteria strains can amplify treatment effectiveness, while specific antibiotics and probiotics can dampen it.
The team used mice lacking the RING finger protein 5 (RNF5) and discovered that these mice could hinder melanoma tumor growth as long as their immune systems and gut microbial populations were thriving. However, when these mice were housed with healthier mice that didn't lack the protein or were treated with antibiotics, their ability to fight melanoma tumors dwindled, demonstrating the critical role gut bacteria play in antitumor defenses.
Further investigation revealed several components of the immune system engaged in the gut, as well as reduced UPR activity in immune and gut cells that activated immune cells. The team went on to transplant the strains of bacteria from RNF5-silenced mice into germ-free mice (no gut bacteria whatsoever) and saw an antitumor response and reduced melanoma tumor growth.
The researchers plan to investigate the antitumor molecules produced by gut bacteria, test their powers, and explore which probiotics might enhance their effectiveness in people with melanoma. They also plan to examine the link between gut inflammation (seeing as RNF5-lacking mice were found to be more susceptible to it) and the balance between autoimmunity and antitumor immunity.
Their aim is to use this research to help more people maximize the benefits of immune therapies and eradicate the little buggers responsible for melanoma.
[1] Microbiotica's MB097: An Oral Microbiome-Based Therapy in the works. [3] The gut-nervous system-immune system axis: A research area showing promise. [4] The role of gut microbiota in cancer treatment outcomes.
- The study published in Nature Communications reveals a group of gut bacteria strains that help slow down the growth of melanoma tumors in mice.
- These 11 identified bacterial strains could potentially personalize immunotherapy treatments for people with melanoma.
- The Unfolded Protein Response (UPR) is a significant pathway connecting gut bacteria and the immune system's antitumor abilities.
- Lower UPR activity in people with melanoma who respond well to immune checkpoint inhibitors suggests it could be a potential marker for positive treatment response.
- Immunotherapy, which empowers the body's internal defense system, presents a promising approach for treating melanoma, but not everyone responds, and side effects can be severe.
- Previous research has shown that certain gut bacteria strains can amplify treatment effectiveness, while specific antibiotics and probiotics can dampen it.
- The study is an encouraging step towards improving the efficacy of immunotherapy treatments for melanoma patients.
- The research team plans to investigate the antitumor molecules produced by gut bacteria, test their powers, and explore which probiotics might enhance their effectiveness in people with melanoma.
