Calothrixin B by docking JAK2 is a potential therapeutic inhibitor for pancreatic ductal adenocarcinoma

Pancreatic cancer, a highly invasive and prognostically unfavorable malignant tumor, consistently exhibits resistance to conventional chemotherapy, leading to substantial side effects and diminished patient quality of life. This highlights the critical need for the discovery of novel, effective, and safe chemotherapy drugs. This study aimed to explore bioactive compounds, particularly natural products, as an alternative for JAK2 protein inhibitor in cancer treatment.

Molecular docking, molecular dynamics, and Western blot experiments were conducted to verify the binding of Calothrixin B to JAK2 and its inhibitory effect on the JAK2-STAT3 signaling axis.

Recognizing the significant impact of JAK-STAT3 signaling pathway in pancreatic cancer, we screened the Zinc database to discover potential JAK2 inhibitors, and identified the small molecule Calothrixin B as a promising drug. Molecular simulations revealed stable interactions and the formation of hydrogen bonds between Calothrixin B and specific amino acids (Asp 994, Leu 855, and Arg 980) after a 100 ns simulation. Furthermore, we show that Calothrixin B inhibited the activity of the JAK2-STAT3 signaling pathway, arrested pancreatic cancer cells in the G1 phase, induced apoptosis, and significantly inhibited cell migration. Moreover, in vivo on a subcutaneous tumor model in nude mice confirmed that Calothrixin B effectively inhibited tumor growth in nude mice. In addition, the combination of Carlothrixin B and gemcitabine had a better inhibitory effect on pancreatic cancer cells.

These findings introduce new avenues for Calothrixin B as promising therapy for pancreatic cancer.