Application of G-quadruplex targets in gastrointestinal cancers: Advancements, challenges and prospects

Figure 2 G-quadruplex targets and the targeting small molecule ligands and biomolecules in six gastrointestinal cancer types. EC: Esophageal cancer; PC: Pancreatic cancer; HCC: Hepatocellular carcinoma; GC: Gastric cancer; CRC: Colorectal cancer, GIST: Gastrointestinal stromal tumor; PPA: 2,6-bis[3-(N-Piperidino) propionamido] anthrace-ne-9,10-dione; PP: Antihelminthic pyrvinium pamoate; ILK: Integrinlinked kinase; PARP1: Poly (ADP-ribose) polymerase 1; APE1: Apurinic/apyrimidinic endonuclease 1; PPRHs: Polypurine reverse Hoogsteen hairpins; DDX5: Dead box polypeptide 5; RHPS4: (3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate) and RHPS4-derivatives; SNRPA: Nuclear ribonucleoprotein polypeptide A; BCL-2: B-cell lymphoma 2; TRA2B: Transformer-2 protein homolog beta; KRAS: Kirsten rat sarcoma viral oncogene homologue; HSP90: Heat shock protein 90; hTERT: Human telomerase reverse transcriptase.