Rewriting our understanding of gastric tumours
The immune system can be an important ally in the fight against cancer. A study from McGill scientists published today inSciencesuggests that the reverse may also be true – that abnormal inflammation triggered by the immune system may underlie the development of stomachtumoursin patients with a hereditary cancer syndrome known asPeutz-JeghersSyndrome (PJS). The findingsare likely topromptare-thinking of how gastrictumoursform in patients with this syndromeandinothers with gastrointestinal cancers. Theyshouldalsoopen the door to potential new treatments based on targeting inflammation rather thantumourcells.
A rare,hereditary cancer syndrome
Peutz-JeghersSyndrome(PJS)is a rare genetic disorder that affects approximately 1 in 150,000 people worldwide.PJS is caused by a mutant, inactive version of a gene (STK11/LKB1) that acts asatumoursuppressorand regulator of cell growth,metabolism, survival and polarity (the way the different elements in the cell are organized).Initial signs of the disease arethe development ofdark blue or brown frecklesaround people’s mouths, eyes,andnostrils. Patients also developbenign polyps– massesof cells that form on the inside lining of their stomach andtheir digestive tract.
Bytheageof65, those with the syndrome havea greater than90 percent chance of developing cancer, includingpancreatic, stomach, ovarian, cervical, colon orbreast cancer.There is currently no cure for PJS.Patients are monitored for cancerdevelopment andoftenrequiresurgery to remove polyps to prevent intestinal blockageandbleeding.
Researcherslooking for a cure forPJShavelongfocused on therole thattheSTK11geneplaysin theepithelial cells of the gastrointestinal tract where polyps,andeventuallytumours,form.But a serendipitous discovery in mice led McGill-based researchersto turn their attention in acompletely differentdirection– the immune system.
A new focus on the immune system
Dr.JuliannaBlagih, whowasstudying therole ofSTK11/LKB1inimmune cells as part ofher Ph.D.thesisat McGill,observed that mice with disruption of theSTK11gene only in T cells– soldiers of the immune system that protect our bodies from infection –developed gastrointestinaltumourssimilar to those found in people with PJS.This observation led Dr.Blagihandher Ph.D. supervisor,Dr.Russell Jones, to explorehowimmunecellsmay contribute todevelopment ofthe disease.
“This is a greatexample of how a random discovery infundamental science inthe lab can lead to new ideas about how diseases are caused, and potentially also to new treatments,”saidDr.Jones,corresponding author of the study andAssociate Professor in the Department of Physiology and theGoodman Cancer Research Centre at McGill. “When weinvestigated further, weconfirmedthatthese were not simply random resultsandthatthe mice with T cells withthesemutationsdevelopedinflammationin theirgastrointestinaltractand polyps similar to those in PJS patients.”
Moreover,Dr. Maya Poffenberger,the lead author and a member of Dr. Jones’ research team,discovered thattelltale signs of inflammation were found in polyps from human PJS patients. She also foundthatpolypdevelopment could be reduced ingenetically-susceptible mice when they were administeredmedication that interruptedspecific inflammatory pathways.
Changing paradigmsforPeutz-JeghersSyndrome
Dr. Jonesadds, “Basically,our workchangestheway we have been thinkingabout this disease, with our focus now on understanding how the immune systemcontributes to polyp development.We hope that our discovery willlead to new treatmentsforPJSpatientsand others withgastrointestinal cancers.We’re pretty excited about it.”
Dr. Jones’next step is to work with mousemodels andtocontinuecollaborationswithcolleagues such asGeorge Zogopoulos andWilliam Foulkes at the 㽶Ƶ Health Centre (MUHC)to studyinpatientstherole of inflammation in the disease.
To read “” byM. C. Poffenberger et alinScience
The research was funded bythe Canadian Cancer Society,the Canadian Institutes of Health Research (CIHR), the McGill Integrated Cancer Research Training Program,andthe Fonds de Recherche du Québec – Santé (FRQS).
About the Goodman Cancer Research Centre
The(GCRC), located within 㽶Ƶ’s Life Sciences Complex, is a state of the art hub for groundbreaking cancer research that attracts and retains top scientists from around the world.Originally established in 1978 as the McGill Cancer Centre, the Centre leads scientific advances that enable us to investigate cancer at a genomic, cellular and molecular level, and understand how cancer progresses, spreads and resists therapies. The Centre currently comprises 27 dedicated research teams with cutting-edge technology platforms, research and support staff and over 200 trainees. Research activities at the GCRC represent a first line of defense in the fight against cancer, with focus on fundamental research to understand why cancers fail to respond to treatment and translating findings into new targets and therapies.
Contacts:
Russell Jones,Goodman Cancer Research Centre, Department ofPhysiology, 㽶Ƶ,russell.jones [at] mcgill.ca,Twitter: (English interviews)
Nicole Beauchemin,Goodman Cancer Research Centre, Department ofPhysiology, 㽶Ƶ,Nicole.beauchemin [at] mcgill.ca(French interviews)
Photocaption:Artist rendition of a growing stomach polyp from aPeutz-JeghersSyndrome patient. The red cells represent pro-inflammatory T cellsthat promotepolyp development. Artist credit: Ella Maru Studio.