Breaking News
February 23, 2019 - Intensive therapy during early stages of MS leads to better long-term outcomes
February 23, 2019 - Prenatal Fluconazole Exposure Increases Neonatal Risks
February 23, 2019 - Mental Health Screening: MedlinePlus Lab Test Information
February 23, 2019 - Study suggests birth mechanics are part of the process that leads to autism
February 23, 2019 - Unhealthy diet linked to poor mental health
February 23, 2019 - Study gives a snapshot of crocodile evolution
February 23, 2019 - Research finds steep rise in self-poisonings among young people
February 23, 2019 - American Gastroenterological Association announces “AGA Future Leaders Program”
February 23, 2019 - Scientists uncover new mechanisms regulating neural stem cells
February 23, 2019 - Combinations of certain insecticides turn out to be lethal for honeybees
February 23, 2019 - AHA News: Why Are Black Women at Higher Risk of Dying From Pregnancy Complications?
February 23, 2019 - NIMH » Anxiety Disorders
February 23, 2019 - Autistic people urgently need access to tailored mental health support
February 23, 2019 - Newly designed molecule could benefit people with Friedrich’s Ataxia
February 23, 2019 - Chinese CRISPR twins may have better cognition and memory
February 23, 2019 - Study finds new genetic clues associated with asthma in African ancestry populations
February 23, 2019 - Fetal signaling pathways may offer future opportunities to treat lung damage
February 23, 2019 - Early-stage osteoarthritis drug wins prestigious innovation award
February 23, 2019 - Researchers report positive findings with dasotraline for ADHD in children ages 6-12
February 23, 2019 - News study reanalyzes the effects of noncaloric sweeteners on gut microbiota
February 23, 2019 - New device allows scientists to reproduce blow effects on the heart in lab
February 23, 2019 - Holy herb identified as a potential treatment for Alzheimer’s disease
February 23, 2019 - New technology platform digitally counts growth factors in single cells
February 23, 2019 - Surgery and other treatments offer viable options for adult scoliosis
February 23, 2019 - Reduced antibody adaptability may make the elderly more vulnerable to influenza
February 23, 2019 - Neighborhood income, education associated with risk of disability progression in MS patients
February 23, 2019 - Endocrine Society opposes new rule that restricts access to Title X Family Planning Program
February 23, 2019 - 2019 guidelines for management of patients with atrial fibrillation
February 23, 2019 - Surprise rheumatoid arthritis discovery points to new treatment for joint inflammation
February 23, 2019 - A just-right fix for a tiny heart
February 23, 2019 - UMass Amherst scientist explores role of citrus peel in decreasing gut inflammation
February 23, 2019 - Owlstone Medical and Shanghai Renji Hospital collaborate to initiate breath biopsy lung cancer trial
February 23, 2019 - AMSBIO’s comprehensive portfolio of knock-out cell lines and lysates
February 23, 2019 - New app reliably determines physicians’ skills in forming accurate, efficient diagnoses
February 23, 2019 - Peripheral nerve injury can trigger the onset and spread of ALS, shows study
February 23, 2019 - Researchers uncover mechanisms that prevent tooth replacement in mice
February 23, 2019 - Once-a-day capsule offers new way to reduce symptoms of chronic breathlessness
February 23, 2019 - FDA Adds Boxed Warning for Increased Risk of Death with Gout Medicine Uloric (febuxostat)
February 23, 2019 - Phone-based intervention aids rheumatoid arthritis care
February 23, 2019 - Opioid epidemic makes eastern inroads and targets African-Americans
February 23, 2019 - New identified biomarker predicts patients who might benefit from HER2-targeted agents
February 23, 2019 - Study offers new insights into mechanisms of changes in erythrocytes under stress
February 23, 2019 - Antipsychotic polypharmacy may be beneficial for schizophrenia patients
February 23, 2019 - Researchers investigate how marijuana and tobacco co-use affects quit attempts by smokers
February 23, 2019 - Patients with diabetes mellitus have high risk of stable ischemic heart disease
February 23, 2019 - Transparency on healthcare prices played key role in Arizona health system’s turnaround
February 23, 2019 - A comprehensive, multinational review of peppers around the world
February 23, 2019 - Study finds modest decrease in burnout among physicians
February 23, 2019 - A simple change can drastically reduce unnecessary tests for urinary tract infections
February 23, 2019 - Deep Learning-Enhanced Device Detects Diabetic Retinopathy
February 23, 2019 - Researchers discover new binding partner for amyloid precursor protein
February 23, 2019 - Modest decrease seen in burnout among physicians, researchers say | News Center
February 23, 2019 - Transplanting bone marrow of young mice into old mice prevents cognitive decline
February 23, 2019 - Mogrify to accelerate novel IP and cell therapies using $3.7m USD funding
February 23, 2019 - Johns Hopkins study describes cells that may help speed bone repair
February 23, 2019 - Scientists demonstrate influence of food odors on proteostasis
February 23, 2019 - Researchers unlock the secret behind reproduction of fish called ‘Mary’
February 23, 2019 - Acupuncture Could Help Ease Menopausal Symptoms
February 23, 2019 - Researchers use AI to detect early signs of Alzheimer’s
February 23, 2019 - On recovery, vulnerability and ritual: An exhibit in white | News Center
February 23, 2019 - Memory Stored in Unexpected Region of the Brain
February 23, 2019 - Several health experts worldwide gather at EUDONORGAN event
February 23, 2019 - Discovery of potent compound in native California shrub may lead to treatment for Alzheimer’s
February 22, 2019 - Researchers create new map of the brain’s own immune system
February 22, 2019 - ICHE’s reviews on surgical infections, unnecessary urine tests, and nurses’ role in antibiotic stewardship
February 22, 2019 - UK Research and Innovation invests £200 million to create new generation of AI leaders
February 22, 2019 - Takeda collaboration to boost fight against Alzheimer’s and other neurodegenerative diseases
February 22, 2019 - Heavy drinking may change DNA, leading to increased craving for alcohol
February 22, 2019 - U.S. opioid deaths jump fourfold in 20 years; epidemic shifts to Eastern states | News Center
February 22, 2019 - 5 Questions with William Turner on Diversity in Medicine
February 22, 2019 - HHS Finalizes Rule Seeking To Expel Planned Parenthood From Family Planning Program
February 22, 2019 - Researchers uncover biochemical pathway that may help identify drugs to treat Alzheimer’s
February 22, 2019 - Biologist uses new grant to find ways to eliminate schistosomiasis
February 22, 2019 - Bag-mask ventilation to help patients breathe during intubation prevents complications
February 22, 2019 - AbbVie Announces New Drug Application Accepted for Priority Review by FDA for Upadacitinib for Treatment of Moderate to Severe Rheumatoid Arthritis
February 22, 2019 - Nature versus nurture and addiction
February 22, 2019 - New website connects researchers with data experts, resources | News Center
February 22, 2019 - Today’s Concerns About Drug Prices Echo The Past
February 22, 2019 - CT and Doppler equipment have low accuracy in detecting cerebral vasospasm and ischemia
February 22, 2019 - Study finds out similarity in function between healthy retina cell and tumor cell
Bacteria promote lung tumor development, study suggests

Bacteria promote lung tumor development, study suggests

image_pdfDownload PDFimage_print
bacteria
Credit: CC0 Public Domain

MIT cancer biologists have discovered a new mechanism that lung tumors exploit to promote their own survival: These tumors alter bacterial populations within the lung, provoking the immune system to create an inflammatory environment that in turn helps the tumor cells to thrive.

In mice that were genetically programmed to develop lung cancer, those raised in a bacteria-free environment developed much smaller tumors than mice raised under normal conditions, the researchers found. Furthermore, the researchers were able to greatly reduce the number and size of the lung tumors by treating the mice with antibiotics or blocking the immune cells stimulated by the bacteria.

The findings suggest several possible strategies for developing new lung cancer treatments, the researchers say.

“This research directly links bacterial burden in the lung to lung cancer development and opens up multiple potential avenues toward lung cancer interception and treatment,” says Tyler Jacks, director of MIT’s Koch Institute for Integrative Cancer Research and the senior author of the paper.

Chengcheng Jin, a Koch Institute postdoc, is the lead author of the study, which appears in the Jan. 31 online edition of Cell.

Linking bacteria and cancer

Lung cancer, the leading cause of cancer-related deaths, kills more than 1 million people worldwide per year. Up to 70 percent of lung cancer patients also suffer complications from bacterial infections of the lung. In this study, the MIT team wanted to see whether there was any link between the bacterial populations found in the lungs and the development of lung tumors.

To explore this potential link, the researchers studied genetically engineered mice that express the oncogene Kras and lack the tumor suppressor gene p53. These mice usually develop a type of lung cancer called adenocarcinoma within several weeks.

Mice (and humans) typically have many harmless bacteria growing in their lungs. However, the MIT team found that in the mice engineered to develop lung tumors, the bacterial populations in their lungs changed dramatically. The overall population grew significantly, but the number of different bacterial species went down. The researchers are not sure exactly how the lung cancers bring about these changes, but they suspect one possibility is that tumors may obstruct the airway and prevent bacteria from being cleared from the lungs.

This bacterial population expansion induced immune cells called gamma delta T cells to proliferate and begin secreting inflammatory molecules called cytokines. These molecules, especially IL-17 and IL-22, create a progrowth, prosurvival environment for the tumor cells. They also stimulate activation of neutrophils, another kind of immune cell that releases proinflammatory chemicals, further enhancing the favorable environment for the tumors.

“You can think of it as a feed-forward loop that forms a vicious cycle to further promote tumor growth,” Jin says. “The developing tumors hijack existing immune cells in the lungs, using them to their own advantage through a mechanism that’s dependent on local bacteria.”

However, in mice that were born and raised in a germ-free environment, this immune reaction did not occur and the tumors the mice developed were much smaller.

Blocking tumor growth

The researchers found that when they treated the mice with antibiotics either two or seven weeks after the tumors began to grow, the tumors shrank by about 50 percent. The tumors also shrank if the researchers gave the mice drugs that block gamma delta T cells or that block IL-17.

The researchers believe that such drugs may be worth testing in humans, because when they analyzed human lung tumors, they found altered bacterial signals similar to those seen in the mice that developed cancer. The human lung tumor samples also had unusually high numbers of gamma delta T cells.

“If we can come up with ways to selectively block the bacteria that are causing all of these effects, or if we can block the cytokines that activate the gamma delta T cells or neutralize their downstream pathogenic factors, these could all be potential new ways to treat lung cancer,” Jin says.

Many such drugs already exist, and the researchers are testing some of them in their mouse model in hopes of eventually testing them in humans. The researchers are also working on determining which strains of bacteria are elevated in lung tumors, so they can try to find antibiotics that would selectively kill those bacteria.


Researchers identify a mechanism that fuels cancer cells’ growth



Provided by
Massachusetts Institute of Technology

Citation:
Bacteria promote lung tumor development, study suggests (2019, January 31)
retrieved 11 February 2019
from https://medicalxpress.com/news/2019-01-bacteria-lung-tumor.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Tagged with:

About author

Related Articles