The protein-coding gene hnRNP K acts as a tumor suppressor in acute myeloid leukemia (AML), according to research published in Cancer Cell.
Investigators found that AML patients who carried a partial deletion of chromosome 9 also experienced a significant decrease in hnRNP K expression.
This deletion, 9q21.32, along with the decreased levels of hnRNP K, led to reduced survival and increased tumor formation.
“Our data implicates hnRNP K in the development of blood disorders and suggests it acts as a tumor suppressor,” said Sean Post, PhD, of The University of Texas MD Anderson Cancer Center in Houston.
“Both in vivo and in vitro results indicate that hnRNP K achieves this through regulation of key genetic pathways. Our study found that hnRNP K expression must be maintained for proper cellular regulation and to prevent tumor formation.”
Dr Post and his colleagues examined hnRNP K’s role in tumorigenesis by generating a mouse model harboring an Hnrnpk knockout allele.
They found that Hnrnpk haploinsufficiency resulted in reduced survival, increased tumor formation, genomic instability, and the development of transplantable hematopoietic neoplasms with myeloproliferation.
“Our findings showed that Hnrnpk haploinsufficiency led to tumor development by deregulating cell proliferation and differentiation programs through control of key cellular pathways, which suggests these pathways may be exploited by targeted therapies,” Dr Post said.
Specifically, he and his colleagues found that reduced hnRNP K expression attenuated p21 activation, downregulated C/EBP levels, and activated STAT3 signaling.
The investigators also analyzed samples from AML patients who harbored 9q21.32 and found a significant decrease in hnRNP K expression.
“It was clear that these changes in AML patients with the 9q21.32 deletion resulted in a tumor suppressor gene involved in blood cancer development,” Dr Post said.
