Cryptotanshinone Inhibits the Proliferation of 5-Fluorouracil-Resistant Gastric Cancer SGC-7901/5-FU Cells Via the JAK2/STAT3 Pathway

Cryptotanshinone (CPT), which is an important active ingredient of herbs, has shown great value for research. In particular, CPT exerts antitumor effects on various types of cancer; however, there are relatively few studies of CPT on gastric cancer cells. The objectives of this study were to investigate how CPT affects apoptosis in 5-fluorouracil-resistant SGC-7901 gastric cancer cells (SGC-7901/5-FU cells) and the molecular mechanism underlying its action. In this study, SGC-7901/5-FU cells were treated with 5-fluorouracil (5-FU) and CPT and the viability of the cells was assessed by CCK8 assay. Additionally, cellular apoptosis rates were evaluated using immunofluorescence and flow cytometry. Related gene expression was evaluated using Quantitative Real-time PCR methods and Western Blot, respectively. CPT inhibited SGC-7901/5-FU cell growth. The immunofluorescence results showed that CPT caused nuclear shrinkage in the cells. Quantitative Real-time PCR and Western Blot results also showed CPT decreased the expression of Mcl-1, Bcl-xl and Bcl-2 levels, and increased the expression of Bax. We demonstrated that CPT can inhibit the growth of SGC-7901/5-FU cells, and the mechanism may be related to the inhibition of the JAK2/STAT3 pathway. Additionally, CPT increased the inhibitory effect of 5-fluorouracil on SGC-7901/5-FU cells, an effect that correlated with changes in cellular resistance.