ASO-Based PKM Splice-Switching Therapy Inhibits Hepatocellular Carcinoma Growth

Abstract

The M2 pyruvate kinase (PKM2) isoform is upregulated in most cancers and plays a crucial role in regulation of the Warburg effect, which is characterized by the preference for aerobic glycolysis over oxidative phosphorylation for energy metabolism. PKM2 is an alternative-splice isoform of the PKM gene and is a potential therapeutic target. Antisense oligonucleotides (ASO) that switch PKM splicing from the cancer-associated PKM2 to the PKM1 isoform have been shown to induce apoptosis in cultured glioblastoma cells when delivered by lipofection. Here, we explore the potential of ASO-based PKM splice switching as a targeted therapy for liver cancer. A more potent lead constrained-ethyl (cEt)/DNA ASO induced PKM splice switching and inhibited the growth of cultured hepatocellular carcinoma (HCC) cells. This PKM isoform switch increased pyruvate-kinase activity and altered glucose metabolism. In an orthotopic HCC xenograft mouse model, the lead ASO and a second ASO targeting a nonoverlapping site inhibited tumor growth. Finally, in a genetic HCC mouse model, a surrogate mouse-specific ASO induced Pkm splice switching and inhibited tumorigenesis, without observable toxicity. These results lay the groundwork for a potential ASO-based splicing therapy for HCC. Significance: Antisense oligonucleotides are used to induce a change in PKM isoform usage in hepatocellular carcinoma, reversing the Warburg effect and inhibiting tumorigenesis.

Increased Expression of NXPH4 Correlates with Immune Cell Infiltration and Unfavorable Prognosis in Hepatocellular Carcinoma

“…The results demonstrated that NXPH4 was positively related with the top coexpressed genes (PKM2, ENO2, SLC16A3, SAPCD2, and PNCK), and all these genes were associated with poor survival of HCC. PKM, ENO2, and SLC16A3 have been researched to have important effects on promoting tumor progression [22][23][24][25][26]. Based on the GO and KEGG pathway analyses, it was suggested that the NXPH4 coexpressed genes play important roles in metabolism and intracellular signaling transduction.…”

Splice‐switch oligonucleotide‐based combinatorial platform prioritizes synthetic lethal targets CHK1 and BRD4 against MYC‐driven hepatocellular carcinoma

“…Prior studies have also exhibited the value of SSOs as candidate therapeutic agents in cancer. 38 , 45 , 46 , 47 , 88 It may therefore be of value to further develop and optimize ssCHK1 and ssBRD4 as potential therapeutic agents against MYC‐driven HCC in a situation where no viable pharmacological agents are available for clinical use. Further chemical modifications to ssCHK1 and ssBRD4 such as the use of a morpholino‐based backbone can render them resistant to enzymatic degradation in biologic fluids and suitable for subsequent clinical applications, as demonstrated in the FDA‐approved SSOs.…”

“… 39 , 40 , 41 , 42 , 43 , 44 Recent advances in SSO technologies have also demonstrated the value of SSOs as candidate RNA therapeutics with significant anticancer properties in in vivo models of HCC, melanoma, prostate, and lung cancer. 38 , 45 , 46 , 47 Additionally, prior applications of SSOs have exhibited dose‐dependent splice‐switch events and is therefore suitable for use in conjunction with QPOP for target prioritization, where the dosages of the therapeutics are considered. 48 …”

SR Splicing Factors Promote Cancer via Multiple Regulatory Mechanisms

“…Another study suggested that highly expressed SRSF10 in head and neck cancer is also associated with aberrant PKM splicing resulting in the expression of PKM2 isoform [ 109 ]. ASO targeting PKM splicing increases the PKM1 to PKM2 ratio, thereby redirecting glucose carbons from anabolic processes to the tricarboxylic acid (TCA) cycle in hepatocellular carcinoma and suppressing the liver-tumor formation and growth [ 110 ].…”