MYC inhibitor(Shenzhen ICarbonX)

Non-small cell lung carcinoma (NSCLC) is a major cause of cancer mortality. High expression of the epithelial-to-mesenchymal transition transcription factor (EMT-TF) Twist1 is strongly associated with metastatic cancers and with treatment resistance. Twist1 can also upregulate O-GlcNAcylation to suppress fail-safe programs such as Kras^G12D oncogene-induced senescence (OIS) that accelerates NSCLC tumorigenesis. We wanted to decipher the critical domains and transcriptional targets required for Twist1 acceleration of lung tumorigenicity. We created a novel genetically-engineered mouse model for autochthonous lung cancer through lung epithelial expression of Kras^G12D oncogene (CR) concomitantly with Twist1^wt (CRT) or a Twist1^F191G transactivation-deficient mutant (CRF191G). Compared to CR and CRF191G, CRT mice had shorter tumor-free survival and more aggressive tumors histologically. CRT lung tumors also showed higher proliferation and lower cell-cycle arrest suggesting that the Twist1 transactivation-domain is important for OIS suppression. Supporting these data, we observed in non-cancer human bronchial epithelial cells (HBECs) that the co-expression of human TWIST1^wt enhanced tumorigenic/invasive programs and could suppress HRas^G12V-induced senescence while co-expressing TWIST1^F187G transactivation-deficient mutant could not. TWIST1^wt co-expression with HRas^G12V in HBECs differentially modulated MYC downstream transcriptional programs. Finally, OIS induction in HBECHRas^G12V-TWIST1^wt was rescued by O-GlcNAcylation inhibition or by treatment with a novel MYC inhibitor MYCi975 or by MYC knockdown. Altogether, these results indicate that the Twist1 transactivation domain is required for Twist1-dependent acceleration of lung tumorigenesis via MYC and nominate MYCi975 as a means to activate latent OIS programs. MYC targeting strategies could limit pro-tumorigenic programs and serve as a therapeutic for TWIST1-overexpressing NSCLCs.

Intracellular delivery is a bottleneck in the development of therapeutic peptides and proteins. Here, we demonstrate the efficient delivery of omoMYC, the first MYC inhibitor in clinical trials, using HBpep-SP, an engineered peptide forming liquid-liquid phase-separated coacervates. HBpep-SP coacervates facilitate efficient cellular uptake and intracellular delivery of the omoMYC peptide at concentrations lower than those required for spontaneous uptake. Strikingly, omoMYC coacervates result in reduced proliferation and apoptosis induction in the low c-MYC expressing cell lines HEK293 and SH-SY5Y cells, but not in HeLa and SK-N-BE(2) cells with high c-MYC/MYCN expression, respectively, suggesting that endogenous MYC/N levels may impact the effects of omoMYC. Importantly, our approach bypasses the need for cell penetration-enhancing chemical modifications, offering a novel strategy for the investigation of peptide drug mechanisms in therapeutic development.