The National Institutes of Health this month issued three grants funding RNAi-related research in cancer including one involving the development of shRNA vectors to study transcription factors associated with tumorigenesis, one examining whether RNAi can be used to suppress a protein linked to leukemia, and one looking at the roles certain microRNAs play in lymphomas.
The NIH also recently announced that the National Institute on Alcohol Abuse and Alcoholism, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Office of Dietary Supplements are seeking funding proposals for projects investigating the mechanism of alcoholic and non-alcoholic fatty liver disease using technologies including RNAi.
The first grant was awarded by the National Cancer Institute to Massachusetts Institute of Technology researcher Jennifer Shepard to support the development of shRNA vectors to study activating E2Fs.
E2Fs are a family of transcription factors that play a role in cell proliferation and have been found to be regulated by the tumor-suppressor gene retinoblastoma, or Rb.
“Rb is functionally inactivated in most human cancers, and the deregulation of E2F family members and their transcriptional targets is believed to be a crucial step in tumorigenesis,” Shepard noted in the grant’s abstract.
“Based on their opposing transcriptional properties, E2Fs can be divided into two classes: the activating E2Fs and the repressive E2Fs,” she explained. “There has been much debate about the relative roles of the activating versus repressive E2Fs in controlling the proliferation of both normal and tumor cells. Moreover, the role of these proteins in ES cell regulation has not yet been addressed.”
With the support of the NCI grant, worth about $49,000, Shepard aims to create an shRNA vector system that will allow inducible knockdown of multiple E2Fs in cultured cells and mouse models.
“These studies will allow us to directly address the requirement of the activating E2Fs in ES cells, primary fibroblasts, and in tumor development,” she stated in the abstract. “Moreover, it will also provide a valuable vector resource to the community that can be used for efficient, simultaneous knockdown of genes of choice.”
The second grant, worth roughly $54,000, was awarded by the National Heart, Lung, and Blood Institute to Jerry Cheng, a researcher at the University of California, Los Angeles, for a project investigating the role of the transcription factor cyclic AMP-responsive element binding protein, or CREB, in hematopoiesis and acute myeloid leukemia.
“We have found that … CREB is overproduced in leukemia stem cells compared to normal stem cells [and have] demonstrated that CREB increases the growth and survival of myeloid cells,” Cheng said of his lab in the grant’s abstract. “We propose to use … RNA interference to knock down CREB in hopes of stopping the growth of leukemia cells.”
According to Cheng, preliminary studies in his lab have shown that knocking down CREB has a significant impact on the growth of myeloid leukemia cell lines. Using RNAi, he is planning to examine the effects of inhibiting CREB in normal bone marrow stem cells to study the transcription factor’s role in hematopoiesis.
After this, Cheng aims to “characterize the effects of RNAi on molecules that activate CREB and promote growth or survival of leukemia cells, [and then] test whether RNAi will slow the progression of leukemia in mice,” he stated in the grant abstract. “These studies will provide new ways of treating AML in hopes of improving the survival of children afflicted with this disease.”
The last grant was awarded to Cold Spring Harbor Laboratory’s Lin He by the National Cancer Institute to fund research into the functions of miRNAs in tumor development and maintenance.
“Recent evidence has suggested that non-coding RNAs, in particular microRNAs, are subjected to changes in gene structure and expression regulation in tumors,” He stated in the grant’s abstract.
“I identified a polycistronic miRNA cluster, mir17-92, as a target of chromosome 13q31 amplicon found in human B-cell lymphomas,” He noted. “In a mouse model for B-cell lymphoma, enforced mir17-92 expression cooperates with c-myc and accelerates tumor growth by repressing cell death … [providing] some of the first functional evidence that changes in miRNAs could contribute to oncogenesis.”
With the grant, which is worth up to $90,000, He proposes to “identify the oncogenic miRNA components within the mir17-92 cluster and to dissect the molecular basis for the tumorigenic effects of mir17-92.”
“We propose to use … RNA interference to knock down CREB in hopes of stopping the growth of leukemia cells.”
After this, He proposes to investigate the effects of mir17-92 on tumors and their response to therapy, and then use combined expression studies, copy number studies, and functional characterization “to examine more broadly the miRNA pathways in the oncogenic and tumor suppressor network. These studies, if successful, will produce fundamental insights into the functions of miRNAs [in cancer] … which can be applied for discovery of both diagnostic markers and therapeutic targets,” He added.
Funding Opportunity for RNAi
According to the NIH, alcoholic liver disease and nonalcoholic fatty liver disease are conditions characterized by fat accumulation in hepatocytes, which leads to steatosis and excess triglyceride deposits.
The funding opportunity, which was issued late last month, is seeking “grant applications that will use an integrative approach of state-of-the-art technologies to gain insight into the molecular mechanisms of both alcoholic and nonalcoholic fatty liver” disease, the NIH said. “This includes investigating the mechanisms by which alcohol and nonalcoholic metabolic factors … accelerate import of free fatty acids into hepatocytes; impair mitochondrial a-oxidation of fatty acids; impede the entry of free fatty acids into mitochondria; promote de novo fatty acid synthesis; promote esterification of free fatty acids into triglycerides; and disrupt export of triglycerides from hepatocytes through very low-density lipoprotein.”
The agencies are encouraging applicants to submit proposals that incorporate novel genomics approaches, such as RNAi, “if a gene or genes is found to play a potential role in the development of alcoholic or nonalcoholic fatty liver,” the NIH noted.
The NIH said that because proposed research projects will vary in scope, “it is anticipated that the size and duration of each award will also vary … [and] awards pursuant to this funding opportunity are contingent upon the availability of funds and the submission of a sufficient number of meritorious applications.”
Applications may be submitted beginning Jan. 5, 2007.