Interleukin 6-triggered ataxia-telangiectasia mutated kinase activation facilitates epithelial-to-mesenchymal transition in lung cancer by upregulating vimentin expression.

Matrix metalloproteinases (MMPs) and the epithelial-mesenchymal transition (EMT) contribute to metastasis. As shown in our previous studies, interleukin-6 (IL-6) induces ATM phosphorylation to increase MMP expression and metastasis in lung cancer. However, the exact roles of ATM activation in the IL-6-induced epithelial-mesenchymal transition and lung cancer metastasis are currently unclear. Here, ATM phosphorylation exerts its pro-metastatic effect via vimentin-mediated epithelial-mesenchymal transition, which was supported by the evidence described below. Firstly, IL-6 treatment increases vimentin expression via the ATM-NF-κB pathway. Second, ATM inactivation not only abolishes IL-6-induced increases in vimentin expression but also inhibits IL-6-induced nest formation in a xenograft lung metastasis model. Moreover, close positive correlations were observed between ATM phosphorylation and vimentin upregulation, IL-6 levels and metastasis in lung cancer specimens. Hence, ATM modulates vimentin expression to facilitate IL-6-induced epithelial-mesenchymal transition and metastasis in lung cancer, indicating that ATM and vimentin might be potential therapeutic targets for inflammation-associated lung cancer metastasis.

TIPE attenuates the apoptotic effect of radiation and cisplatin and promotes tumor growth via JNK and p38 activation in Raw264.7 and EL4 cells.

Tumor necrosis factor α­induced protein 8 (TIPE) is highly expressed in many types of malignancies. Apoptosis is the process of programmed cell death which maintains the balance of cell survival and death. TIPE is involved in the carcinogenesis of many tumor types, yet the exact role of TIPE in defective apoptosis­associated carcinogenesis remains uncertain. In the present study, TIPE­overexpressing Raw264.7 and EL4 cells and vector control cells were treated with 4 mJ/cm2 ultraviolet radiation or 2 µg/ml cisplatin. Following ultraviolet irradiation, TIPE overexpression decreased the percentage of apoptotic cells as detected by flow cytometric and reversed the cisplatin­mediated decrease in mitochondrial membrane potential by JC­1 assay. Western blot analyses also revealed that TIPE overexpression inhibited cisplatin­induced activation of caspase­3 and ­9 and PARP. Secondly, TIPE overexpression increased the levels of phosphorylated JNK, MEK and p38. Moreover, inhibition of JNK and p38, but not MEK, efficiently abolished the cell pro­survival effect of TIPE. Most importantly, an in vivo tumor implantation model revealed that TIPE overexpression augmented the volume and weight of the implanted tumors, indicating that TIPE facilitated tumor formation. We found that TIPE exhibited an anti­apoptotic effect via JNK and p38 activation, which ultimately promoted tumor. Hence, the present study revealed that activation of JNK and p38 kinases contribute to the TIPE­mediated anti­apoptotic effect, indicating that JNK and p38 may be potential therapeutic molecules for TIPE overexpression­associated diseases.

Nicotine promotes cell proliferation and induces resistance to cisplatin by α7 nicotinic acetylcholine receptor­mediated activation in Raw264.7 and El4 cells.

Although nicotine is a risk factor for carcinogenesis and atherosclerosis, epidemiological data indicate that nicotine has therapeutic benefits in treating Alzheimer's disease. Our previous studies also showed that nicotine-treated dendritic cells have potential antitumor effects. Hence, the precise effects of nicotine on the biological characterizations of cells are controversial. The aim of the present study was to assess the roles of α7 nicotinic acetylcholine receptors (nAChRs), Erk1/2-p38-JNK and PI3K-Akt pathway in nicotine-mediated proliferation and anti-apoptosis effects. The results firstly showed that nicotine treatment clearly augmented cell viability and upregulated PCNA expression in both Raw264.7 and El4 cells. Meanwhile, nicotine afforded protection against cisplatin-induced toxicity through inhibiting caspase-3 activation and upregulating anti-apoptotic protein expression. Further exploration demonstrated that nicotine efficiently abolished cisplatin-promoted mitochondria translocation of Bax and the release of cytochrome c. The pretreatment of α-bungarotoxin and tubocurarine chloride significantly attenuated nicotine-augmented cell viability, abolished caspase-3 activation and α7 nAChR upregulation. Both Erk-JNK-p38 and PI3K-Akt signaling pathways could be activated by nicotine treatment in Raw264.7 and El4 cells. Notably, when Erk-JNK and PI3K-Akt activities were inhibited, nicotine-augmented cell proliferation and anti-apoptotic effects were abolished accordingly. The results presented here indicate that nicotine could achieve α7 nAChR-mediated proliferation and anti-apoptotic effects by activating Erk-JNK and PI3K-Akt pathways respectively, providing potential therapeutic molecules to deal with smoking-associated human diseases.

Camptothecin and cisplatin upregulate ABCG2 and MRP2 expression by activating the ATM/NF-κB pathway in lung cancer cells.

Multidrug resistance (MDR) formation is an important problem in lung cancer chemotherapy. Our study showed that both camptothecin and cisplatin could not only induce ATM and NF-κB activation but also upregulate expression of the MDR-related genes ABCG2, MRP2 in NCI-H446 cells. Moreover, camptothecin and cisplatin-induced ABCG2 and MRP2 upregulation could be impaired by ATM and NF-κB inhibitors, indicating a relationship between ATM, NF-κB activation and MDR formation in lung cancer chemo-therapy. Our study indicates that ATM may serve as a potential molecular target for MDR formation in lung cancer chemotherapy.

TGF-ß of lung cancer microenvironment upregulates B7H1 and GITRL expression in dendritic cells and is associated with regulatory T cell generation.

The effects of TGF-ß on dendritic cells (DCs) on the tumor microenvironment are not well understood. We report, here, the establishment of an in vitro lung cancer microenvironment by co-incubation of seminaphtharhodafluor (SNARF) labeled Lewis lung cancer (LLC) cells, carboxyfluorescein succinimidyl ester (CFSE) labeled fibroblasts and 4-chloromethyl-7-hydroxycoumarin (CMHC) labeled DCs. Raw 264.7, EL4 and NCI-H446 cells were able to synthesize TGF-ß which was determined by flow cyto-metry and western blotting, respectively. Furthermore, TGF-ß efficiently increased regulatory T-cell (Treg) expansion and upregulated DC B7H1 and GITRL expression. TGF-ß and the co-incubation of LLC cells, fibroblasts with DCs could augment the expression of B7H1 and GITRL molecules of DCs. The data presented here indicate that the B7H1 and GITRL molecules may play an important role in TGF-ß-induced Treg expansion of lung cancer microenvironment.

Lipopolysaccharide and dose of nicotine determine the effects of nicotine on murine bone marrow-derived dendritic cells.

The reported effects of nicotine on dendritic cells (DCs) are controversial. To investigate the factors which determine the effects of nicotine on DCs, immature dendritic cells (imDCs) induced from murine bone marrow were treated with different doses of nicotine with or without lipopolysaccharides (LPS). The morphology and expression of the co-stimulatory molecules CD80, CD86, CD40 and CD54 were observed and determined by microscopy and flow cytometry, respectively. The results showed that, firstly, nicotine treatment promoted the development of DC precursors into imDCs with a semi-mature phenotype revealed by a higher expression of CD11c and more branched projections. Secondly, lower doses of nicotine (16.5 ng/ml), but not higher (200 µg/ml), up-regulated the expression of the co-stimulatory molecules CD80, CD40 and CD54 on imDCs. Co-administration of LPS and nicotine revealed differential effects on co-stimulatory molecule expression on imDCs. Thirdly and importantly, treatment with lower doses of nicotine (16.5 ng/ml) did not augment expression of the CD80, CD86, CD40 and CD54 molecules in mature DCs. Fourthly and interestingly, high doses of nicotine (more than 165 µg/ml) revealed pro-apoptotic activity but lower doses of nicotine (16.5-0.165 ng/ml) achieved an anti-apoptotic effect on imDCs. All data presented here indicate that the controversial effects of nicotine on DCs may be due to the LPS of the nicotinic environment and the dose of nicotine used.

Minimally invasive treatment for severely displaced proximal humeral fractures in children using titanium elastic nails.

OBJECTIVE: To evaluate the preliminary results of minimally invasive treatment for severely displaced proximal humeral fractures in children using titanium elastic nails (TENs). METHODS: Twenty-five cases of TEN treatment of severely displaced proximal humerus fractures in children were evaluated clinically and radiographically. Complications were assessed. The 14 males and 11 females were between 6 and 15 years of age at the time of surgery. Of the 10 left and 15 right humeri treated, 3 were open fractures and 2 were associated with polytrauma. Two laterally inserted retrograde TENs were used in 22 cases. In the remaining 3 cases, 1 medial and 1 lateral TEN were inserted retrograde. RESULTS: Follow-up ranged from 7 to 40 months. All fractures showed both clinical and radiographic evidence of healing within 2 months. There were no major complications related to the treatment. There were 3 cases of skin irritation adjacent to prominent distal ends of the nails, of which the 2 nails in 1 child were removed prematurely at 3 weeks without sequelae. The nails in the other 2 cases were removed at the planned 6-month postoperative time with complete resolution of symptoms. Function of the fractured arm returned to normal quickly in all cases. CONCLUSIONS: TEN for the treatment of severely displaced humerus fractures in children is an effective method with a low complication rate.