No abstract

Chemoresistance is an inevitable occurrence in lung adenocarcinoma, which has been associated with decreased expression of the phosphatase and tensin homolog deleted on chromosome ten (PTEN). Therefore, it is important to identify novel molecular mechanisms to suppress chemoresistance in lung adenocarcinoma cells. Paclitaxel- and cisplatin-resistant A549 lung carcinoma cell derivatives were developed by long-term serial culture. The metastatic properties of the cells were assessed using wound-healing assays, migration assays, invasion assays, morphological examination, and western blot analysis/RT-PCR of genes associated with the epithelial-mesenchymal transition (EMT). To identify novel regulators of EMT in A549 cells, differentially expressed miRNAs in drug-resistant cells were identified by microarray analysis. The role of miR-181a was established by transfection with specific mimic and inhibitor followed by functional assays. Luciferase assays were performed to assess the ability of miR-181a to target the PTEN promoter, and regulation of PTEN expression by miR-181a was assessed by western blot analysis and RT-PCR. Paclitaxel- and cisplatin-resistant A549 cells acquired metastatic properties and EMT phenotype and had reduced PTEN expression as compared to sensitive cells. miR‑181a was identified as a differentially expressed miRNA in drug-resistant A549 cells, and miR-181a mimic and inhibitor were shown to affect migration, invasion, morphology and expression of EMT-associated genes. PTEN was identified as a direct target of miR-181a. Our findings demonstrate that miR-181a expression in lung adenocarcinoma is associated with EMT progression, potentially through targeting of PTEN. Regulation of miR-181a may provide a novel strategy for overcoming resistance to paclitaxel and cisplatin in lung adenocarcinoma.

A recent study indicated that high Wnt5a expression is associated with poor prognosis in non-small-cell lung cancer (NSCLC) patients; however, the underlying mechanism was not clear yet. Immunohistochemistry and Western blotting were performed to examine the protein expression level in NSCLC tissues and cell lines. The role of Wnt5a in clone formation, invasiveness, migration, and epithelial-to-mesenchymal transition (EMT) of NSCLC cells was studied. Luciferase reporter assay was used to evaluate the Tcf/Lef transcriptional activity. For assessing the effects of Wnt5a on tumor growth and metastasis in vivo, A549 cells transfected with sh-Wnt5a were subcutaneously or orthotopically injected into nude mice. In NSCLC tissues, higher expression levels of Wnt5a and ROR2 were found, β-Catenin was expressed exceptionally, and EMT was prompted. Wnt5a overexpression increased clone formation, migration, and invasion, as well as prompted EMT of NSCLC cell in vitro, whereas Wnt5a knockdown showed the absolutely reversed results. Wnt5a overexpression enhanced the Tcf/Lef transcriptional activity and elevated the nuclear β-catenin level in NSCLC cells, without altering the ROR2 expression. We also demonstrated that si-β-catenin antagonized Wnt5a overexpression nduced EMT and invasiveness. Besides, in vivo experiment showed that sh-Wnt5a significantly increased tumor volume and tumor weight, and prompted EMT in A549 tumor-bearing mice as compared with the control. No metastasis was found in the liver tissue after sh-Wnt5a-transfected cells were orthotopically injected into nude mice as compared with the control. In conclusion, Wnt5a promotes EMT and metastasis in NSCLC, which is involved in the activation of β-catenin-dependent canonical Wnt signaling.

The rapid growth in demand for lithium ion batteries (LIBs) results in the generation of a vast amount of spent LIBs. Recovery of valuable metals from spent LIBs is required in terms of environmental protection and natural resource conservation. Here, we developed a novel process for the sustainable recovery of Li and Co from spent LiCoO 2 cathodes based on in situ reductive roasting. In the operation of reductive roasting, Al foil in the cathode performs as an in situ reductive reagent converting LiCoO 2 into Li 2 O, CoO, and Al 2 O 3 . Lithium and aluminum in roasting products can be selectively leached in a NaOH solution with a leaching efficiency of 93.67% and 95.59%, respectively. In the meantime, cobalt, in the form of CoO, is concentrated in the alkaline leaching residue, which can be completely dissolved in H 2 SO 4 solution. The obtained CoSO 4 solution with Co concentration higher than 160 g/L is beneficial for the following evaporation and crystallization operation. Comparing with traditional processes, the present in situ reductive roasting process features as no need for separation of active materials from Al and none external reductants adding, which can make the recycling process of spent LIBs simpler, more sustainable, and more economical.