Tariq Rana

Stem cells 101

by Communications Staff on October 8, 2012 at 10:52 am | 2 Comments

Sanford-Burnham's Stem Cell Research Center

Congratulations to John B. Gurdon and Shinya Yamanaka on winning the 2012 Nobel Prize in Physiology or Medicine! They received the award today for their “discovery that mature cells can be reprogrammed to become pluripotent.” In other words, these scientists figured out how to turn a normal adult cell, such as a skin cell, into a stem cell that has the potential to become any other type of cell in the body. Read below to learn more about stem cells and how they are revolutionizing medical research.

What are stem cells?

Stem cells are special because each is like a blank slate. Once it’s given the proper instruction, a stem cell can specialize and become any type of cell in the body—brain, heart, muscle, and more. Stem cells also have the ability to reproduce themselves indefinitely, renewing the supply.

Are there different types of stem cells?

Embryonic stem cells only exist during an organism’s development, when it is an embryo. These cells are pluripotent, meaning they have the capacity to become any cell type in the body.

Adult stem cells exist in fully developed organisms. They are more limited than embryonic stem cells—they are multipotent rather than pluripotent. These stem cells usually can only become a few types of specialized cells, based on the tissue from which they originate.

Induced pluripotent stem cells (iPSCs) are pluripotent, much like embryonic stem cells. iPSCs are produced in the laboratory by genetically reprogramming any adult cell, such as a skin cell.

Making it easier to make stem cells

by Heather Buschman, Ph.D. on September 25, 2012 at 8:01 am | 1 comment

Full Article

Induced pluripotent stem cells (iPSCs) generated using a kinase inhibitor

The process researchers use to generate induced pluripotent stem cells (iPSCs)—a special type of stem cell that can be made in the lab from any type of adult cell—is time consuming and inefficient. To speed things up, researchers at Sanford-Burnham turned to kinase inhibitors. These chemical compounds block the activity of kinases, enzymes responsible for many aspects of cellular communication, survival, and growth. As they outline in a paper published September 25 in Nature Communications, the team found several kinase inhibitors that, when added to starter cells, help generate many more iPSCs than the standard method. This new capability will likely speed up research in many fields, better enabling scientists around the world to study human disease and develop new treatments.

“Generating iPSCs depends on the regulation of communication networks within cells,” explained Tariq Rana, Ph.D., program director in Sanford-Burnham’s Sanford Children’s Health Research Center and senior author of the study. “So, when you start manipulating which genes are turned on or off in cells to create pluripotent stem cells, you are probably activating a large number of kinases. Since many of these active kinases are likely inhibiting the conversion to iPSCs, it made sense to us that adding inhibitors might lower the barrier.”

According to Tony Hunter, Ph.D., professor in the Molecular and Cell Biology Laboratory at the Salk Institute for Biological Studies and director of the Salk Institute Cancer Center, “The identification of small molecules that improve the efficiency of generating iPSCs is an important step forward in being able to use these cells therapeutically. Tariq Rana’s exciting new work has uncovered a class of protein kinase inhibitors that override the normal barriers to efficient iPSC formation, and these inhibitors should prove useful in generating iPSCs from new sources for experimental and ultimately therapeutic purposes.” Hunter, a kinase expert, was not involved in this study.

It’s a trap! New laboratory technique captures microRNA targets

by Heather Buschman, Ph.D. on May 9, 2012 at 9:43 am | 3 Comments

Full Article

Huricha Baigude, Ph.D., postdoctoral researcher and first author of the study

Human cells are thought to produce thousands of different microRNAs (miRNAs)—small pieces of genetic material that help determine which genes are turned on or off at a given time. miRNAs are an important part of normal cellular function, but they can also contribute to human disease—some are elevated in certain tumors, for example, where they promote cell survival. But to better understand how miRNAs influence health and disease, researchers first need to know which miRNAs are acting upon which genes—a big challenge considering their sheer number and the fact that each single miRNA can regulate hundreds of target genes. Enter miR-TRAP, a new easy-to-use method to directly identify miRNA targets in cells. This technique, developed by Tariq Rana, Ph.D., professor and program director at Sanford-Burnham, and his team, was first revealed in a paper published May 8 by the journal Angewandte Chemie International Edition.

“This method could be widely used to discover miRNA targets in any number of disease models, under physiological conditions,” Rana said. “miR-TRAP will help bridge a gap in the RNA field, allowing researchers to better understand diseases like cancer and target their genetic underpinnings to develop new diagnostics and therapeutics. This will become especially important as new high-throughput RNA sequencing technologies increase the numbers of known miRNAs and their targets.”

Read More

An easier (and safer) route to stem cell therapies

by Bruce Lieberman on October 31, 2011 at 9:32 am | 0 Comments

Full Article

Chao-Shun Yang, graduate student in Dr. Tariq Rana's lab and first author of the study

Many research labs around the world are focused on finding the most effective ways to reprogram an adult cell (a skin cell, for example) into induced pluripotent stem cells (iPSCs)—that is, cells that have the ability to develop into other tissues in the body. These cells not only offer researchers powerful tools to study a particular patient’s individual disease, but they have the potential to therapeutically replace diseased or damaged tissue in the patient from whom the cells originated.

Most experiments to reprogram adult cells employ viruses as vehicles to carry four particular genes—called reprogramming factors—into the nucleus of a cell. But genetic engineering carries its own risks, including the chance that these cells will continue replicating, eventually forming a tumor. What’s more, scientists are not exactly sure what the reprogramming factors do, on the molecular level, to promote the generation of iPSCs.

Could there be a safer and more predictable way to alter the expression of genes in cells, thereby reprogramming their DNA so they revert to their earlier, more malleable state?

Personalized Medicine 101

by Amelia Tomas on April 21, 2011 at 3:54 pm | 1 comment

Full Article

Dr. Steven Smith, Scientific Director for the Florida Hospital Sanford-Burnham Translational Research Institute, demonstrates sophisticated equipment used in metabolic studies.

Dr. Steven Smith, Scientific Director for the Florida Hospital Sanford-Burnham Translational Research Institute, cares for a patient.

In 2003, the completion of the human genome project gave us an unprecedented amount of genetic information. From this, a new clinical concept is emerging: personalized medicine.

Conventional medical care generalizes treatment to all patients with a particular disease. But since a disease is as individual as the person who has it, casting a wide therapeutic net has its limitations. For one, patients with a certain genetic makeup might not respond to a particular drug as well as patients with different genetics, or they might experience different side effects. As personalized medicine becomes a reality, it could rectify these less-than-ideal situations.

From the diagnostic point-of-view, personalized medicine is a shift from reactive to proactive. Based on a person’s health, genetic, and environmental profiles, doctors practicing personalized medicine could assess a patient’s risk for acquiring a genetic disease before any symptoms develop. This might allow them to target the specific genes that account for illness (the BRCA1/BRCA2 genes that predispose a woman to breast cancer, for example), incorporate a prevention strategy, and monitor those genes over time. When it comes to treatment, personalized drugs could be prescribed based on an individual’s molecular “build” and targeting treatment where it will do the most good and the least harm.

New recipe for iPS cells

by Heather Buschman, Ph.D. on February 2, 2011 at 4:00 am | 2 Comments

Full Article

Stem cells are ideal tools to understand disease and develop new treatments because they can self-renew (generate more cells in a dish) and differentiate (become a wide variety of cell types). They can be differentiated into heart muscle cells, for example, which could then be used to replace damaged heart tissue. Where do scientists get stem cells? In the early days of stem cell research, investigators could isolate stem cells from pathological specimens of the brain or bone marrow. More recently, they have figured out how to make a special kind of stem cell called an induced pluripotent stem cell (iPS cell) from almost any type of adult cell, such as a skin cell. Researchers can then use iPS cells to study human development or to create “disease in a dish”, a technique that allows them to model an individual patient’s specific disease and screen for personalized treatments.

But generating iPS cells can be an arduous task. Reprogramming differentiated adult cells into iPS cells requires so many steps and so much time that the efficiency rate is very low – you might end up with only a few iPS cells even if you started with a million skin cells. So a team set out to improve the process. In a paper published February 1, 2011 in The EMBO Journal, they uncovered microRNAs (miRNAs) that are important during reprogramming and exploited them to make the transition from skin cell to iPS cell more efficient.

“We identified several molecular barriers early in the reprogramming process and figured out how to remove them using miRNA,” said Dr. Tariq Rana, senior author of the study. “This is significant because it will enhance our ability to use iPS cells to model diseases in the laboratory and search for new therapies.”

Hibernating herpes viruses

by Heather Buschman, Ph.D. on October 14, 2010 at 9:39 am | 1 comment

Full Article

Herpes viruses are good at hiding. They infect human cells and lay dormant there until replication is activated by stress or some other environmental factor. One type, Kaposi’s sarcoma-associated herpesvirus (KSHV), is one of only a few viruses known to cause cancer.

In a study that appeared online September 17 in the journal EMBO Reports, Sanford-Burnham’s Dr. Tariq Rana and colleagues found that KSHV stays quiet by expressing certain microRNAs (miRNAs), small strands of genetic material that interfere with protein production.

“KSHV dormancy is believed to be essential for tumor formation, yet some forms of cancers caused by the virus have also been linked to viral reactivation,” explains Dr. Rana, professor and director of Sanford-Burnham’s RNA Biology Program. “This study helps us better understand the KSHV life cycle, thus providing new insight into how the virus causes cancer in some populations.”

RNApalooza

by Josh Baxt on May 13, 2010 at 1:14 pm | 1 comment

Full Article

Until recently, RNA had been thought of simply as a messenger, transferring encoded information from our DNA to ribosomes, which produce proteins. But in the past 10 years, scientists have found that specific types of RNA, called microRNA and RNAi, play a significant role in controlling which genes are turned on or off—processes that could have a profound impact on human health.

On May 7, scientists from around the country came to Sanford-Burnham’s 32nd Annual Scientific Symposium to discuss the implications of these small RNAs and how we can use them to fight disease.

It’s a small RNA world

by Josh Baxt on April 23, 2010 at 6:00 am | 0 Comments

Full Article

We’re oversimplifying a little, but our genetic code works like this: DNA codes for messenger RNA (mRNA); mRNA takes that coded message out of the nucleus; tiny machines called ribosomes read the message in the mRNA and produce proteins; proteins do most of the work in the cell. However, there is another player in this pathway that has only come to light relatively recently—microRNAs(miRNAs).

Stem cells 101

What are stem cells?

Are there different types of stem cells?

Read More

Making it easier to make stem cells

It’s a trap! New laboratory technique captures microRNA targets

An easier (and safer) route to stem cell therapies

Personalized Medicine 101

New recipe for iPS cells

Hibernating herpes viruses

RNApalooza

It’s a small RNA world

Search

Find more information

Please take a quick survey

Which of these items describes you?

Categories

What are stem cells?

Are there different types of stem cells?

Search

Find more information

Please take a quick survey

Which of these items describes you?

Categories

Search by Keyword