Cancer genomics and sequencing have allowed researchers to discover new types of cellular control switches. For example, using sequencing, they have discovered a new type of RNA, called circular RNA, which seems to be prevalent in certain cancers. While circular RNAs exist in normal cells, there are cancer-specific ones that are highly expressed in some types of cancer.
A computational biologist now at the McGovern Medical School at the University of Texas Health Science Center at Houston hopes to better understand circular RNA in order to potentially use it as a cancer biomarker or therapeutic target.
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Cancer genomics and sequencing have allowed researchers to discover new types of cellular control switches. For example, using sequencing, they have discovered a new type of RNA, called circular RNA, which seems to be prevalent in certain cancers. While circular RNAs exist in normal cells, there are cancer-specific ones that are highly expressed in some types of cancer.
A computational biologist now at the McGovern Medical School at the University of Texas Health Science Center at Houston hopes to better understand circular RNA in order to potentially use it as a cancer biomarker or therapeutic target.
Leng Han was recruited in 2015 from the University of Texas MD Anderson Cancer Center, where he was a postdoctoral fellow. He received a First-Time Tenure-Track Award from CPRIT, and joined the department of biochemistry & molecular biology.
Unlike most RNA, which is linear, circular RNA forms, well, a circle. Recent studies have shown that circular RNAs may play roles in regulating the functions of genes that code for proteins, but these processes are not fully understood.
Circular RNA is more stable than linear RNA, which also makes it less prone to degrade inside human tissues and easier to detect in urine or blood. Certain circular RNAs appear only in particular cancer types or in a particular cancer stage, which might someday make them convenient biomarkers to detect or stage cancers. Han hopes that once circular RNAs are better understood, they might also serve as therapeutic targets.
Han is also studying other RNAs that don’t code for proteins—which is RNA’s most well understood role. He found a non-coding RNA in cancer that seems to be involved in the proliferation of cancer cells. Using genetic knockout techniques, he discovered that if this non-coding RNA is knocked out, the cells don’t multiply out of control.
Han’s other role as a computational geneticist is helping other researchers access and understand the complex data generated from cancer genome sequencing. With the advent of large databases like The Cancer Genome Atlas (TCGA), clinicians and researchers have access to bewildering volumes of information. Tens of thousands of complete sequences of cancer genomes from dozens of different types of cancer await discoveries. Han said discoveries made using TCGA have already lowered the mortality rate for cancer in general.
Han is making it easier for researchers to search for particular relationships, such as the ratio of circular RNA in cancer vs. normal cells. “We can show them whether circular RNA is up-regulated in cancer types compared to normal cells, and compare among different cancer stages—early or late,” he says. “Since TCGA also contains patient survival data, the researchers can choose their target to perform further experiments.”
He’s also planning to apply his expertise to studying the function of non-coding RNAs involved in immunotherapy, because it’s such a promising new field.
CPRIT has provided generous support that enabled Han to hire multiple postdocs to work in his lab. Han says he hopes to use it to leverage additional funding from the National Institutes of Health.
Han received his undergraduate degree in biotechnology from Wuhan University in Wuhan, China, and his Ph.D. in genetics & bioinformatics from the Chinese Academy of Sciences in Kunming. He spent two years as a postdoctoral fellow at Stanford University before coming to MD Anderson as a postdoctoral fellow in 2012.
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