Abstract
For over three decades, K-RAS has been known as the holy grail of cancer targets, one of the most frequently mutated oncogenes in cancer. Because the development of conventional small molecule K-RAS inhibitors has been extremely challenging, K-RAS has been dubbed as an undruggable target, and only recently a mutation specific inhibitor has reached clinical trials. Targeted protein degradation has emerged as a new modality in drug discovery to tackle undruggable targets. However, no degrader for K-RAS has been described thus far. Our laboratory has developed an Affinity-directed PROtein Missile (AdPROM) system for targeted proteolysis of endogenous proteins through the ubiquitin proteasome system. Here, we show that we can achieve degradation of endogenous K-RAS and H-RAS in different cell lines in a targeted manner using our AdPROM system. Our findings imply that endogenous RAS proteins can be targeted for proteolysis, thereby offering tantalising possibilities for an alternative therapeutic approach to these so-called undruggable targets in cancer.
List of abbreviations
- AdPROM
- Affinity directed PROtein Missile
- ASC
- Apoptosis-associated speck-like protein containing a CARD
- ATPB
- ATP synthase subunit β
- BRAF – B
- Rapidly Accelerated Fibrosarcoma
- Cas9
- CRISPR associated protein 9
- CRBN
- Cereblon
- CRISPR
- Clustered Regularly Interspaced short palindromic repeats
- CUL
- Cullin
- DAPI
- 4,6-diamidino-2-phenylindole
- DARPIN
- Designed Ankyrin Repeat Protein
- FACS
- Fluorescence Activated Cell Sorting
- FKBP
- FK506 Binding Protein
- GAP
- GTPase Activating Protein
- GAPDH
- Glyceraldehyde 3-phosphate dehydrogenase
- GDP
- Guanosine diphosphate
- GEF
- Guanosine Nucleotide Exchange Factor
- GFP
- Green Fluorescent Protein
- GTP
- Guanosine triphosphate
- HIF1α
- Hypoxia Inducible Factor 1α
- HVR
- Hypervariable region
- MAPK
- Mitogen Activated Protein Kinase
- NSCLC
- Non-small cell lung carcinoma
- PAWS1
- Protein associated with Smad1
- PI3K
- Phosphoinositide 3-kinase
- qRT-PCR
- Real-time quantitative RT-PCR
- RAS
- Rat Sarcoma
- RBX1
- RING box protein 1
- SDS-PAGE
- SDS Polyacrylamide Gel Electrophoresis
- SHP2
- Src homology region 2 (SH2)-containing protein tyrosine phosphatase 2
- UPS
- Ubiquitin Proteasome System
- VHL
- Von-Hippel-Lindau
- VPS34
- Vacuolar protein sorting 34