Lung cancer is a major public health problem worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer cases. Autophagy has recently sparked great interest, and it is thought to participate in a variety of diseases, including lung cancer. Uncoordinated (Unc) 51-like kinase 1 (Ulk1), a serine/threonine kinase, plays a central role in the autophagy pathway. However, the role of Ulk1 in NSCLC remains unclear. We report that NSCLC cell lines exhibited high expression of Ulk1 and that Ulk1 was negatively correlated with prognosis in lung cancer patients. Knockdown of Ulk1 or the inhibition of Ulk1 by the selective inhibitor SBI0206965, inhibited cell proliferation, induced cell apoptosis and enhanced the sensitivity of cisplatin against NSCLC cells. Moreover, we demonstrated that Ulk1 exerted oncogenic activity in NSCLC by modulating both autophagy and apoptosis pathways. Inhibition of autophagy by SBI0206965 sensitized NSCLC cells to cisplatin by inhibiting cisplatin induced cell-protective autophagy to promote apoptosis. Furthermore, SBI0206965 promoted apoptosis in NSCLC cells independent of autophagy, which was partly mediated by destabilization of Bcl2/Bclxl. In summary, our results show that inhibition of Ulk1 suppresses NSCLC cell growth and sensitizes NSCLC cells to cisplatin by modulating both autophagy and apoptosis pathways, and that Ulk1 might be a promising target for NSCLC treatment.

Evidences suggest that tumor microenvironment may play an important role in cancer drug resistance. Sphingosine kinase 2 (SphK2) is proposed to be the key regulator of sphingolipid signaling. This study is aimed to investigate whether the combination of molecular targeting therapy using a specific inhibitor of SphK2 (ABC294640), with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can enhance the apoptosis of non-small cell lung cancer (NSCLC) cells. Our results revealed that NSCLC cells' sensitivity to TRAIL is correlated with the level of SphK2. Compared with TRAIL alone, the combination therapy enhanced the apoptosis induced by TRAIL, and knockdown of SphK2 by siRNA presented a similar effect. Combination therapy with ABC294640 increased the activity of caspase-3/8 and up-regulated the expression of death receptors (DR). Additional investigations revealed that translocation of DR4/5 to the cell membrane surface was promoted by adding ABC294640. However, expression of anti-apoptosis proteins such as Bcl(-)2 and IAPs was not significantly modified by this SphK2 inhibitor. Overall, this work demonstrates that SphK2 may contribute to the apoptosis resistance in NSCLC, thus indicating a new therapeutic target for resistant NSCLC cells.

Histone deacetylases (HDACs) are promising targets for cancer therapy, and first-generation HDAC inhibitors are currently in clinical trials for the treatment of cancer patients. HDAC6, which is a key regulator of many signaling pathways that are linked to cancer, has recently emerged as an attractive target for the treatment of cancer. In the present study, HDAC6 was found to be overexpressed in lung adenocarcinoma cell lines and was negatively correlated with the prognosis of patients with lung adenocarcinoma. Overexpression of HDAC6 promoted the proliferation of lung adenocarcinoma cells in a deacetylase activity-dependent manner. HDAC6 overexpression conferred resistance to gefitinib via the stabilization of epidermal growth factor receptor (EGFR). The inhibition of HDAC6 by CAY10603, a potent and selective inhibitor of HDAC6, inhibited the proliferation of lung adenocarcinoma cells and induced apoptosis. CAY10603 downregulated the levels of EGFR protein, which in turn inhibited activation of the EGFR signaling pathway. Moreover, CAY10603 synergized with gefitinib to induce apoptosis of the lung adenocarcinoma cell lines via the destabilization of EGFR. Taken together, our results suggest that the inhibition of HDAC6 may be a promising strategy for the treatment of lung adenocarcinoma.

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The growing incidence of cancer raises an urgent need to develop effective diagnostic and therapeutic strategies. With the rapid development of nanomedicine, nanoscale metal-organic frameworks (NMOFs) presented promising potential in various biomedical applications in the last 2 decades, especially in cancer theranostics. Due to the unique features of NMOFs, including structural diversities, enormous porosity, multifunctionality and biocompatibility, they have been widely used to deliver imaging contrast agents and therapeutic drugs. Moreover, multiple types of contrast agents, anti-cancer drugs and targeting ligands could be co-delivered through one single NMOF to enable combination therapy. Co-delivering system using NMOFs helped to avoid multidrug resistance, to reduce adverse effects, to achieve imaging-guided precise therapy and to enhance anti-cancer efficacy. This review summarized the recent research advances on the application of NMOFs in biomedical imaging and cancer treatments in the last few years. The current challenges that impeding their translation to clinical practices and the perspectives for their future applications were also highlighted and discussed.