Targeting receptor tyrosine kinases in ovarian cancer: Genomic dysregulation, clinical evaluation of inhibitors, and potential for combinatorial therapies

Tephrosin Suppresses the Chemoresistance of Paclitaxel-Resistant Ovarian Cancer via Inhibition of FGFR1 Signaling Pathway

Ovarian cancer is the leading cause of death among gynecologic cancers. Paclitaxel is used as a standard first-line therapeutic agent for ovarian cancer. However, chemotherapeutic resistance and high recurrence rates are major obstacles to treating ovarian cancer. We have found that tephrosin, a natural rotenoid isoflavonoid, can resensitize paclitaxel-resistant ovarian cancer cells to paclitaxel. Cell viability, immunoblotting, and a flow cytometric analysis showed that a combination treatment made up of paclitaxel and tephrosin induced apoptotic death. Tephrosin inhibited the phosphorylation of AKT, STAT3, ERK, and p38 MAPK, all of which simultaneously play important roles in survival signaling pathways. Notably, tephrosin downregulated the phosphorylation of FGFR1 and its specific adapter protein FRS2, but it had no effect on the phosphorylation of the EGFR. Immunoblotting and a fluo-3 acetoxymethyl assay showed that tephrosin did not affect the expression or function of P-glycoprotein. Additionally, treatment with N-acetylcysteine did not restore cell cytotoxicity caused by a treatment combination made up of paclitaxel and tephrosin, showing that tephrosin did not affect the reactive oxygen species scavenging pathway. Interestingly, tephrosin reduced the expression of the anti-apoptotic factor XIAP. This study demonstrates that tephrosin is a potent antitumor agent that can be used in the treatment of paclitaxel-resistant ovarian cancer via the inhibition of the FGFR1 signaling pathway.

Molecular modeling, synthesis, and antiproliferative evaluation of new isoxazole ring linked by Schiff bases and azo bond

Lung cancer is the most common malignancy worldwide, with approximately 1.8 million new cases yearly. Cytotoxic drugs are frequently used in cancer treatment. Even though the medicine enhances patients' quality of life, several drawbacks diminish its efficacy. Drug resistance and many disadvantages associated with chemotherapeutic drug side effects continue to be significant factors limiting the efficiency of cancer treatment. This necessitates developing new effective strategies that target tumors with minimal adverse effects. This research aims to overcome these issues by synthesizing a new series of compounds with an isoxazole ring attached by Schiff bases and azo bonds based on molecular docking with the (Genetic Optimization of Ligand Docking) program and estimating the pharmacokinetic properties with the Swiss ADME. The greatest-fitting compounds were then manufactured and verified by spectral analysis (FT-IR, 1H NMR, and 13C NMR), in vitro MTT assay for assessment of antiproliferative activities against A549 lung cancer cell lines showed that compounds 5a and 5b had an inhibitory concentration half-maximal inhibitory concentration (IC50) (17.34 and 18.32 μM), respectively, which was significantly lower than the inhibitory concentration of erlotinib (IC50 = 25.06 μM).