Hypocrellin A exerts antitumor effects by inhibiting the FGFR1 signaling pathway in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer, which is the deadliest form of cancer worldwide. Recent studies have shown that genes in the fibroblast growth factor (FGF) family are highly mutated in lung cancer, and fibroblast growth factor receptor 1 (FGFR1) has been found to be involved in various cancers, including lung cancer, suggesting that FGFR1 is a valid therapeutic target. Hypocrellin A (HA), a molecule with multiple biological activities, has been shown to influence cancer growth, but the specific mechanisms of its antitumor action have not been fully explored. METHODS: MTT, colony formation, wound healing, transwell cell invasion and EdU cell proliferation assays were performed upon HA treatment of three NSCLC cell lines, H460, PC-9 and H1975. Hoechst 33258 staining and caspase 3 activity assays were carried out to investigate the impact of HA on apoptosis in these cells. Molecular docking and surface plasmon resonance were conducted to assess binding of HA to FGFR1. A mouse tumor model was used to detect the NSCLC-inhibitory ability of HA in vivo. RESULTS: Through in vitro assays, HA was shown to negatively impact cell viability, migration, invasion and promote apoptosis in three human NSCLC cell line models. HA was shown to bind to FGFR1 and to inhibit its autophosphorylation and the phosphorylation of downstream signaling molecules. Inhibition of tumor growth was also demonstrated in a mouse xenograft tumor model, and no toxic effects of HA treatment were observed. CONCLUSIONS: HA inhibits the activity of the FGFR1 and STAT3 signaling pathways. HA thus represents a potential new FGFR1-targeted treatment for NSCLC.

Neobavaisoflavone Demonstrates Valid Anti-tumor Effects in Non-Small- Cell Lung Cancer by Inhibiting STAT3.

AIM AND OBJECTIVE: Lung cancer is the most commonly occurring cancer, which contributes to the majority of death caused by cancer, where non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer. To treat NSCLC, STAT3 has been identified as a target with therapeutic potential. The neobavaisoflavone (NBIF) is one of the flavonoids of traditional Chinese medicine Psoralea corylifolial. MATERIALS AND METHODS: Human NSCLC cell lines, PC-9, H460, and A549, were applied to determine NBIF's anti-proliferative effects through cell viability and colony formation detection. The effect of NBIF on cell apoptosis was determined through flow cytometry-based assay. Western blotting was used in this study to confirm the levels of P-STAT3, Bcl-2, and Bax, which are apoptotic proteins. RESULTS: It was observed that NBIF could decrease the cell viability and its migration and induce apoptosis in human NSCLC cell lines dose-dependently. Levels of P-STAT3, as well as the downstream signals of the STAT3 pathway, were downregulated, suggesting that the tumorsuppression effects of NBIF might be related to the inhibition of STAT3 signaling. Furthermore, NBIF could contribute to the upregulation of BAX and downregulation of BCL2. CONCLUSION: NBIF might perform the anti-NSCLC efficacy as a result of the inhibition of the STAT3 pathway. Besides, our work suggests that NBIF could provide therapeutic alternatives for NSCLC.

Effect of the isoflavone corylin from cullen corylifolium on colorectal cancer growth, by targeting the STAT3 signaling pathway.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide. Corylin is an isoflavone extracted from Cullen corylifolium (L.) Medik., which is widely used anti-inflammatory and anticancer in Asian countries. Signal transducer and activator of transcription 3 (STAT3) plays an important role in the occurrence and development of CRC. PURPOSE: To analyze the antitumor activity of corylin in CRC and to elucidate its molecular mechanisms of action. METHODS: The human CRC cell lines HCT116, RKO, and SW480 and immunodeficient mice were used as models to study the antitumor effect of corylin. The potent anti-proliferative, anti-migration and proapoptotic effects of corylin were observed by cell viability, colony formation assays, wound-healing migration assay, and cell apoptosis assay. Immunostaining analysis and western blot analysis revealed inhibition of the STAT3 signaling axis. RESULTS: We found that corylin could significantly reduce the viability and stimulate apoptosis in human CRC cells in a dose-dependent manner. Corylin decreased the expression levels of P-STAT3 and STAT3 target proteins, such as myeloid cell leukemia-1(MCL-1), Survivin, VEGF and B-cell lymphoma 2 (BCL-2). It also upregulated the expression levels of the proapoptotic proteins BCL-2-associated X protein (BAX) and Cl-caspase 3. Moreover, corylin reduced the nuclear localization of STAT3. Furthermore, corylin inhibited the growth of the tumor in CRC mouse models. CONCLUSIONS: Our findings provide convincing results that could support the role of corylin in the treatment of CRC through inhibiting the STAT3 pathway. It is conceivable that corylin should be further explored as a unique STAT3 inhibitor in antitumor therapy.

Flubendazole demonstrates valid antitumor effects by inhibiting STAT3 and activating autophagy.

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is an oncogene, which upregulates in approximately 70% of human cancers. Autophagy is an evolutionarily conserved process which maintains cellular homeostasis and eliminates damaged cellular components. Moreover, the STAT3 signaling pathway, which may be triggered by cancer cells, has been implicated in the autophagic process. METHODS: In this study, we found that the anthelmintic flubendazole exerts potent antitumor activity in three human colorectal cancer (CRC) cell lines and in the nude mouse model. The inhibition of cell proliferation in vitro by flubendazole was evaluated using a clonogenic assay and the MTT assay. Western blot analysis, flow cytometry analysis, siRNA growth experiment and cytoplasmic and nuclear protein extraction were used to investigate the mechanisms of inhibiting STAT3 signaling and activation of autophagy induced by flubendazole. Additionally, the expression of STAT3 and mTOR was analyzed in paired colorectal cancer and normal tissues collected from clinical patients. RESULTS: Flubendazole blocked the IL6-induced nuclear translocation of STAT3, which led to inhibition of the transcription of STAT3 target genes, such as MCL1, VEGF and BIRC5. In addition, flubendazole also reduced the expression of P-mTOR, P62, BCL2, and upregulated Beclin1 and LC3-I/II, which are major autophagy-related genes. These processes induced potent cell apoptosis in CRC cells. In addition, flubendazole displayed a synergistic effect with the chemotherapeutic agent 5-fluorouracil in the treatment of CRC. CONCLUSIONS: Taken together, these results indicate that flubendazole exerts antitumor activities by blocking STAT3 signaling and inevitably affects the autophagy pathway. Flubendazole maybe a novel anticancer drug and offers a distinctive therapeutic strategy in neoadjuvant chemotherapy of CRC.