GARDNER, Mass.—New England Peptide (NEP) and the Atlantic CancerResearch Institute (ACRI) have jointly submitted a patent application forcancer-related peptide reagents which the companies believe have the potentialto deliver breakthroughs in cancer diagnostics and more individualizedtherapies for cancer patients.
The patent application's principal claims the series of peptide reagentsis capable of capturing exosomes and/or microvesiclesfrom cell culture media and various tissue fluids, and that the captured materialsare primarily and specifically oriented towards any type of cancer.
"The concepts of enabling discovery in exosomeresearch and understanding the need to expedite cancer diagnoses and improveaccuracy of treatments are the main tenets of the patent," says Dr.Steve Griffiths, researcher at Moncton, New Brunswick-based ACRI, andco-inventor of the new peptides. "Existing methods give comparatively loweryields and thus present missed opportunities for detection andcharacterization."
One of the hallmarks of cancer cells is their high propensity to "budoff" their cellular material into small particles called microvesicles andexosomes. These particles carry a variety of information about the parentcancer cell that recently has become a primary focus of research. Earlyfindings from cell cultures grown in the lab indicate their potential, but tomaximize the overall benefit, scientists need to use cells from "real-life"samples.
"Real-life samples," in this case, refers to easilycollected samples such as blood or urine, states Scott Lewis, co-inventor anddirector of NEP's Antibody Division. The currently accepted method for thecollection and testing of potential cancerous material—the biopsy of detectedtumors—is invasive, expensive and, because in many cases tumors are not evenlooked for until the patient is quite ill, too late to be effective, henotes.
On the other hand, the collection and subsequenttesting of blood or urine samples is far easier and often already done on ayearly basis.
"Because of the comparative differencein ease and practicality between the two methods, the potential of catchingrelevant data at much earlier stages would be greatly increased," Lewis says."The mRNA, miRNA and protein information found in microvesicles and exosomesthus far has already revealed known cancer biomarkers. Further research enabledby these reagents will be extremely useful in creating profiles of specificcancer types, as well as providing insight into how and why some cancersprogress into being lethal and others do not."
The idea of using exosomes as a potential source of molecules ofdiagnostic, prognostic and theranostic interest hasbeen generating steam ever since they were first discovered to contain knownbiomarkers for cancer. The problem with doing this on a widespread basis is thedifficulty in collecting exosomes from whatever biological tissue is beingused, since they are typically a very small part of the total material presentin any sample.
"The current accepted method for exosomepurification—ultracentrifugation—involves spinning a sample at very high speeds(a centrifugal force of 100,000g) to concentrate the exosomes into a pellet atthe bottom of a test tube," notes Griffiths.
However, because of the limited number of labs withmachines capable of such high speeds—and the popularity of such machines inthese facilities—ultracentrifugation can be a major bottleneck in exosomeanalysis, he notes. Furthermore, without direct access to an ultracentrifuge,renting time at a facility can be a significant expense.
"Since our reagents do not requireultracentrifugation, the time and expense related to this as an issue has beenremoved," he states.
"Adding these two advantages together, one can easilyenvision the advent of personalized testing," ACRI's Griffiths adds.
His vision is that each patient would be examined forindicators of cancer of a specific threat (including severity and type) andaccording to the results—rather than gambling on broad-spectrum approaches oftreatment that may be both inefficient and at times severely debilitating—atreatment plan would be tailored to their exact needs.
NEP's Lewis agrees: "This would give untold cumulativebenefit to insurance companies, healthcare professionals and patients alike,"he observes.
Moving forward, ACRI will continue to refine thereagents through its research programs and at the same time identify newapplications for the derived products. NEP will be responsible formanufacturing and commercialization.