New model could speed up colon cancer research: Introducing … – Science Daily
Posted: May 3, 2017 at 4:44 pm
Using the gene-editing system known as CRISPR, MIT researchers have shown in mice that they can generate colon tumors that very closely resemble human tumors. This advance should help scientists learn more about how the disease progresses and allow them to test new therapies.
Once formed, many of these experimental tumors spread to the liver, just like human colon cancers often do. These metastases are the most common cause of death from colon cancer.
"That's been a missing piece in the study of colon cancer. There is really no reliable method for recapitulating the metastatic progression from a primary tumor in the colon to the liver," says Omer Yilmaz, an MIT assistant professor of biology, a member of MIT's Koch Institute for Integrative Cancer Research, and the lead senior author of the study, which appears in the May 1 issue of Nature Biotechnology.
The study builds on recent work by Tyler Jacks, the director of the Koch Institute, who has also used CRISPR to generate lung and liver tumors in mice.
"CRISPR-based technologies have begun to revolutionize many aspects of cancer research, including building mouse models of the disease with greater speed and greater precision. This study is a good example of both," says Jacks, who is also an author of the Nature Biotechnology paper.
The paper's lead authors are Jatin Roper, a research affiliate at the Koch Institute and a gastroenterologist at Tufts Medical Center, and Tuomas Tammela, a research scientist at the Koch Institute.
Mimicking human tumors
For many years, cancer biologists have taken two distinct approaches to modeling cancer. One is to grow immortalized human cancer cells known as cancer cell lines in a lab dish. "We've learned a lot by studying these two-dimensional cell lines, but they have limitations," Yilmaz says. "They don't really reproduce the complex in vivo environment of a tumor."
Another widely used technique is genetically engineering mice with mutations that predispose them to develop cancer. However, it can take years to breed such mice, especially if they have more than one cancer-linked mutation.
Recently, researchers have begun using CRISPR to generate cancer models. CRISPR, originally discovered by biologists studying the bacterial immune system, consists of a DNA-cutting enzyme called Cas9 and short RNA guide strands that target specific sequences of the genome, telling Cas9 where to make its cuts. Using this process, scientists can make targeted mutations in the genomes of living animals, either deleting genes or inserting new ones.
To induce cancer mutations, the investigators package the genes for Cas9 and the RNA guide strand into viruses called lentiviruses, which are then injected into the target organs of adult mice.
Yilmaz, who studies colon cancer and how it is influenced by genes, diet, and aging, decided to adapt this approach to generate colon tumors in mice. He and members of his lab were already working on a technique for growing miniature tissues known as organoids -- three-dimensional growths that, in this case, accurately replicate the structure of the colon.
In the new paper, the researchers used CRISPR to introduce cancer-causing mutations into the organoids and then delivered them via colonoscopy to the colon, where they attached to the lining and formed tumors.
"We were able to transplant these 3-D mini-intestinal tumors into the colon of recipient mice and recapitulate many aspects of human disease," Yilmaz says.
More accurate modeling
Once the tumors are established in the mice, the researchers can introduce additional mutations at any time, allowing them to study the influence of each mutation on tumor initiation, progression, and metastasis.
Almost 30 years ago, scientists discovered that colon tumors in humans usually acquire cancerous mutations in a particular order, but they haven't been able to accurately model this in mice until now.
"In human patients, mutations never occur all at once," Tammela says. "Mutations are acquired over time as the tumor progresses and becomes more aggressive, more invasive, and more metastatic. Now we can model this in mice."
To demonstrate that ability, the MIT team delivered organoids with a mutated form of the APC gene, which is the cancer-initiating mutation in 80 percent of colon cancer patients. Once the tumors were established, they introduced a mutated form of KRAS, which is commonly found in colon and many other cancers.
The scientists also delivered components of the CRISPR system directly into the colon wall to quickly model colon cancer by editing the APC gene. They then added CRISPR components to also edit the gene for P53, which is commonly mutated in colon and other cancers.
"These new approaches reduce the time frame to develop genetically engineered mice from two years to just a few months, and involve very basic gene engineering with CRISPR," Roper says. "We used P53 and KRAS to demonstrate the principle that the CRISPR editing approach and the organoid transplantation approach can be used to very quickly model any possible cancer-associated gene."
In this study, the researchers also showed that they could grow tumor cells from patients into organoids that could be transplanted into mice. This could give doctors a way to perform "personalized medicine" in which they test various treatment options against a patient's own tumor cells.
Yilmaz' lab is now using these techniques to study how other factors such as metabolism, diet, and aging affect colon cancer development. The researchers are also using this approach to test potential new colon cancer drugs.
Read the original post:
New model could speed up colon cancer research: Introducing ... - Science Daily
- Gene Therapy Could Prevent Blindness [Last Updated On: June 10th, 2010] [Originally Added On: June 10th, 2010]
- Gene Brodland Sits with Cambridge Who's Who in a Revealing Interview [Last Updated On: June 16th, 2010] [Originally Added On: June 16th, 2010]
- Researchers Make Colon Cancer Breakthrough [Last Updated On: July 20th, 2010] [Originally Added On: July 20th, 2010]
- Pro abortion- Antiabortion myth8 - Fly to India for safe abortion! [Last Updated On: October 16th, 2010] [Originally Added On: October 16th, 2010]
- New Fertility Test / Whooping Cough Alert / Gene Therapy for Depression [Last Updated On: October 21st, 2010] [Originally Added On: October 21st, 2010]
- Alzheimer's Breakthrough? [Last Updated On: October 23rd, 2010] [Originally Added On: October 23rd, 2010]
- Audio Genetics Lab - Native Flute - MP3Tera Forums [Last Updated On: December 8th, 2010] [Originally Added On: December 8th, 2010]
- Gene Therapy - Cortical Studios [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- There Shall Be Physicians for the Spirit: USC Institute for Genetic Medicine Art Gallery [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- IRRI: Rice genetic diversity and discovery [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Research Symposium: Mork Depart - 2006 - Video 1 [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Mendelian Genetics [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Ayurveda [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Drs. Kaspar and MacKenzie discuss the promise and path forward for SMA Gene Therapy [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- 3. Genetic Engineering [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Prof. Martinez Cruzado Lecture Part 3 "Amerindian Gene Study In Puerto Rico" [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Gene Therapy Research Makes Nationwide Children's Worthy of Wellstone Center [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Gene Therapy Example [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Sweet Tooth Gene [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- OHSU's video of new gene therapy method developed at the Oregon National Primate Research Center [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Gregor Mendel's Punnett Squares [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Ethical Concerns With Genetic Engineering [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Dr. Laura Niklason on the importance of her AFAR grants for telomerase gene therapy research [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- What is the future of genetic medicine? [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Prof. Martinez Cruzado Lecture Part 2 "Amerindian Gene Study In Puerto Rico" [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Jewish DNA - Genetic Research and The Origins of the Jewish People [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Future of genetic engineering - by Futurist Dr Patrick Dixon. Genetic mutations and genetic disorders. Gene science by conference keynote speaker [Last Updated On: May 11th, 2011] [Originally Added On: May 11th, 2011]
- annstewart82's Genetic Medicine and God [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Genetic research could unlock breeding seasons in sheep [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Genetics 101 Part 1: What are genes? [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Molecular and Cellular Foundations of Medicine, 1 of 2 [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Dan Arking of Johns Hopkins Medicine [Last Updated On: May 17th, 2011] [Originally Added On: May 17th, 2011]
- Genetics : How Is Gene Therapy Done? [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene Therapy Shows Promise for Blindness [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Tomato suicide gene therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Cancer Alternative Treatment - Gene Therapy for Cancer a Report from Channel 4 News [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Muscular Dystrophy Gene Therapy: ScienCentral News Video [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Sickle Cell Anemia -- Hope from Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Challenges of gene therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Pain Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene therapy success 'reverses' blindness [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- DNA Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- The Neural Circuitry of Perception [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Resetting Metabolism- Nuclear Receptors and AMPK: A Lecture by Ronald Evans, PhD [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Islands at Risk (Part 2) - Genetic Engineering in Hawai'i [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Xiao Xiao on gene therapy for muscular dystrophy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- HYBRID HUMANS-Hair Follicle Gene Therapy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Genetics 101 Part 4: What is phenotype? [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Lloyd Pye - Ancient Genetic Engineering [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Study Designs: Genetic Association Studies [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Gene Therapy for Genetic Disease: The Long and Winding Road [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Introduction to Population Genetics [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Islands at Risk (Part 1) - Genetic Engineering in Hawai'i [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Genetics Based Research on Treatment-Resistant Epilepsy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Science in Action: Gene Therapy for Color Blindness [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Gregg Semenza of Johns Hopkins Medicine on HIF 1 [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- The Sleepiness Gene [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Blind Gene Therapy [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Richard Dawkins and Dr Yan on genetic ancestry (extended version) - Bang Goes the Theory - BBC One [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Joshua Mendell of Johns Hopkins Medicine [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Genetic/Genomic Faculty Champion Initiative (PM session) [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- euronews science - Epigenetics [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- The Genetic Age, Panel 1 [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Biobanking and Bioethics: When Genetics Research Hits the Courts [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Darren Wolfe on gene therapy for pain.m4v [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetics 101 Part 3: Where do your genes come from? [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- ASHG 2010 Mtg.: "Complex Disease Genetics Research in Populations" (Dr. Carlos Bustamente) [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Public Talk - Prof Leonard Seymour, Oxford [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- A New Era in Medicine: Genetics [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetic Engineering Animation [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Linda Brzustowicz - Genetic Causes of Schizophrenia [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Hadassah Gene Therapy Center [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Robin Ali on gene therapy for retinal disease [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- UF cardiologists study gene-modified stem cells to help Dobermans with common heart condition [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Akhilesh Pandey of Johns Hopkins Medicine [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- China's Cancer Drug - China [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetic Therapy Restored Boy's Sight [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Molecular and Cellular Foundations of Medicine Class, 2 of 2 [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Talking Research - Professor George Ebers - Vitamin D and genetics in MS [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Designing Humanity - Genetic Engineering [Last Updated On: May 30th, 2011] [Originally Added On: May 30th, 2011]