This is important because it cansurely be used to successfully detect early stage cancer with serious success. This is something that has not been possiblein any meaningful way in the past. Sofar though, the method could possibly be available once because it wouldpresently trigger an immune response.
On the other hand, we believethat cancer takes years to show up although there is also good reason toquestion that.
The method is designed to allowcancer sells to be lit up, allowing easy discovery. Assuming that this can also be used as a drugdelivery system we have another plausible effective tool against cancer.
Genetically Altered Virus Detects Cancers Early
Released: 5/9/2011 7:00 AM EDT
Embargo expired: 5/11/2011 5:00 PM EDT
Newswise — CINCINNATI – Scientists have used a geneticallyre-engineered herpes virus that selectively hunts down and infects canceroustumors and then delivers genetic material that prompts cancers to secrete abiomarker and reveal their presence.
According to a study appearing May 11 in PLoS (Public Library ofScience) ONE, the novel technology has the potential to vastly improve cancerdiagnosis by allowing the disease to be caught at much earlier stages and tomonitor the effectiveness of therapy.
Researchers at Cincinnati Children’s Hospital Medical Center
“Our study represents a proof-of-principle in mice, and there iscertainly room for further refinement. If ultimately validated in human trials,it could have implications for people with known cancer risk or who have ahistory of cancer and high risk of recurrence,’’ said Timothy Cripe, M.D.,Ph.D., senior investigator on the study and a physician and researcher in theDivision of Oncology at Cincinnati Children’s.
“Early cancer detection is vital to improve cure rates because cancerstage predicts prognosis, but biomarkers are known for only a few cancer types.We were able to use a reprogrammed herpes virus administered intravenously todeliver genetic information that induces a known blood biomarker for cancer tobe secreted by cancer cells,” explained Dr. Cripe, who collaborated on thestudy with first author, Andrew Browne, Ph.D., a fourth-year medical student atthe University of Cincinnati (UC) College of Medicine and a recent graduatefrom UC’s Department of Electrical and Computer Engineering.
The researchers engineered a herpes simplex virus mutant they calledrQ-M38G, reprogramming its genetic makeup so it bypasses healthy tissues andinstead targets rapidly dividing cancer cells for infection. They also geneticallyarmed the virus so it prompts cancer cells to secrete Gaussia luciferase(GLuc).
GLuc is a luminescent, easily detectable protein the researchersused as a universal blood biomarker for cancer cells infected by rQ-M38G.Because rQ-M38G/GLuc might also help shrink cancer, it is part of a new classof agents dubbed “theragnostics” that can simultaneously be used for diagnosisand therapy, Dr. Cripe said.
Initially the researchers tested rQ-M38G on laboratory cell cultures ofhealthy dormant human skin cells and on rapidly dividing cancer cells. Virusreplication and biomarker production were very low in the dormant normal cells.In contrast, virus replication and biomarker production were much higher intumor cell lines of malignant peripheral nerve sheath tumors, osteosarcoma(bone cancer), rhabdomyosarcoma (muscle cancer) and Ewing sarcoma.
Researchers then tested the virus’s detection capabilities in mousemodels of these same cancers by injecting rQ-M38G into their tail veins, andfor comparison into the tail veins of healthy control mice. Non-tumor bearingmice showed background signals for the virus without significant replicationsor biomarker production. More than 90 percent of the tumor bearing mice showedsignificant virus replication and biomarker production.
The technology even worked in some mice with only microscopic amountsof cancer in their kidneys, researchers report. If it were to work as well inhumans, the scientists estimate that hidden tumors less than half-inch indiameter might be detectable. Because of the anticipated immune responseagainst the virus and the GLuc protein in humans, further refinements of thetechnology will likely be needed to be able to use it more than once.
The study is one more example of the expanding research into usingreprogrammed HSV as novel methods to treat or diagnose cancer, especially asmedicine reaches the limits of modern chemotherapies. Dr. Cripe said thiscreates an urgent need for new strategies against stubborn metastatic disease.Less than 30 percent of patients with metastatic cancer survive beyond fiveyears, despite the aggressive use of modern combination therapies that includechemotherapy.
Also collaborating on the current study were Jennifer Leddon, MarkCurrier, Jon Williams, Jason Frischer, and Margaret Collins all of CincinnatiChildren’s.
Funding support for the study came from The Cancer Free Kids PediatricCancer Research Alliance
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