Background/Aims: Periostin is upregulated in non-small cell lung cancer (NSCLC). This study was done to explore the function of periostin in the development of cisplatin (CDDP) resistance in NSCLC. Methods: The effects of overexpression or knockdown of periostin on CDDP sensitivity was examined in A549 cells. The involvement of signal transducer and activator of transcription 3 (Stat3) and Akt signaling in the action of periostin was checked. The in vivo effect of periostin silencing on CDDP susceptibility was determined in a mouse xenograft model. Results: Periostin was significantly upregulated in CDDP-resistant A549 cells, compared to parental controls. Overexpression of periostin rendered A549 cells more resistant to CDDP-induced apoptosis and enhanced Stat3 and Akt phosphorylation and survivin expression. Periostin-mediated protection against CDDP-induced apoptosis was compromised by downregulation of survivin. Furthermore, knockdown of periostin re-sensitized CDDP-resistant A549 cells to CDDP. After CDDP treatment, greater volume reduction was observed in periostin-silenced xenograft tumors than in control tumors, which was accompanied by reduced levels of phosphorylated Stat3 and survivin in periostin-depleted tumors. Conclusion: In conclusion, periostin promotes CDDP resistance in NSCLC cells largely through activation of Stat3 and Akt and upregulation of survivin and thus represents a promising target for overcoming CDDP resistance.

Platelet-derived growth factor (PDGF) and its receptors (PDGFR), including PDGFRα and PDGFRβ, play important roles in tumorigenesis, tumor progression, and the regulation of stromal cell function. Constitutive activation of PDGFR signaling, gene rearrangement, and activating mutations of PDGFR have been identified in various types of human tumors and malignancies. PDGFRα and PDGFRβ belong to the family of type III receptor tyrosine kinases and, upon stimulation, activate downstream signaling cascades. Crenolanib is a specific tyrosine kinase inhibitor that targets and inhibits the kinase activity of PDGFR and the FMS-related tyrosine kinase 3. Its clinical efficacy in several human tumors is currently under investigation in Phase II clinical trials. In this study, we examined the potential role of crenolanib in the treatment of non-small-cell lung cancer (NSCLC). Using A549 cells as a model system, we have shown that crenolanib is capable of suppressing proliferation and inducing apoptosis in a dose-dependent manner. Crenolanib-treated cells have reduced migratory activity in response to inducers of chemotaxis. Furthermore, the in vivo antitumor activity of crenolanib was confirmed in an NSCLC xenograft tumor model. Injection of crenolanib significantly inhibited the growth of tumor mass by inducing apoptosis in tumor cells. Our results provide strong evidence supporting the use of crenolanib as a potential therapeutic agent in treating NSCLC. This work sets a foundation for further development of targeted and personalized therapeutics for lung cancer.

Abstract.Increasing evidence has shown that microRNA (miRNA) is extensively involved in the pathophysiology of lung cancer. Microarray data demonstrated the increasing levels of miR-19a in the peripheral blood from patients suffering from lung cancer, which is closely associated with poor prognosis of lung cancer. However, the underlying molecular mechanism of miR-19a remains to be determined. The results of the present study showed a higher expression of miR-19a compared with normal bronchial epithelial cells. Furthermore, lentivirus vectors were constructed to establish cell lines that over expressed and knocked out miR-19a in order to study the role of miR-19a on the metastasis and proliferation of lung cancer cells. Investigation into the underlying mechanism of miR-19a, revealed that MXD1 may be the key gene targeting miR-19a, participating in the process of proliferation and metastasis of lung cancer cells.

No abstract