CLPTM1L is believed to be associated with lung cancer. However, there is little information regarding its expression and function. Here using immunohistochemistry, we found that CLPTM1L expression was markedly increased in lung cancer tissues relative to normal tissues, especially in lung adenocarcinoma. CLPTM1L expression was not found to be associated with stages, smoking status, lymph node metastasis, or T lymphocyte infiltration but with differentiation stage. We found CLPTM1L to be enriched in the mitochondrial compared with plasma membrane protein extracts. CLPTM1L-EGFP transfection showed that the molecule product was expressed in cytoplasm and indicated the mitochondrial localization stained with mitochondrial marker MitoTracker. CLPTM1L transferred lung cancer cell line 95-D showed no growth inhibition or cell apoptosis, but it did show inhibited sensitivity to cis-diamminedichloroplatinum(II) (cisplatin, CDDP). Knockdown of CLPTM1L by RNAi did not interfere with cell proliferation but it did increase cell sensitivity to CDDP and activation of caspase-9 and caspase-3/7. These data indicate CLPTM1L is a mitochondria protein and that it may be associated with anti-apoptotic mechanism which affects drug-resistance in turn.

Background/Aims: A growing number of studies have demonstrated that the activity and expression level of sirtuin-1 (SIRT1) are decreased in asthma patients; however, the mechanisms underlying decreased SIRT1 expression and function are still not completely understood. Interleukin (IL)-6 plays important roles in inflammation during allergic asthma. In this study, we examined whether loss of SIRT1 activity regulated the expression of IL-6 and further verified the underlying mechanisms. Methods: The human airway epithelial cell line 16HBE was used to test the effects of the SIRT1 inhibitor (salermide) on expression of IL-6. IL-6 mRNA and protein expression were assessed with real-time polymerase chain reaction (PCR), immunochemistry, and ELISA. OVA-challenged mice were used as an asthma model to investigate the effect of SIRT1 activation on IL-6 and relative Akt phosphorylation level. Results: We found that inhibition of SIRT1 increased IL-6 mRNA and protein levels in a time-dependent manner, which was accompanied by increased Akt pathway activation in 16HBE cells. Furthermore activation of Akt showed upregulated expression of the IL-6 protein whereas Akt inhibitor, LY294002 or Akt siRNA significantly inhibited SIRT1-regulated IL-6 expression. Conversely, activation of SIRT1 inhibited Akt activation and IL-6 expression in an asthmatic mice model and 16HBE cells. Conclusion: Our results indicate the potential role of SIRT1 in regulating inflammation by modulation of IL-6 expression in an Akt-dependent manner during allergic asthma.

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Resveratrol, a natural polyphenolic compound known for its antioxidative and antiinflammatory effects, exerts antiasthmatic effects, although the mechanism underlying these effects remains elusive. The phosphatase and tensin homology deleted on chromosome ten gene (PTEN) is involved in the pathogenesis of asthma, and PTEN overexpression in asthmatic mice improved asthma symptoms. To investigate whether the antiasthmatic mechanisms of resveratrol correlated with the upregulation of PTEN expression, an ovalbumin (OVA)-induced murine asthma model was used to determine the effectiveness of resveratrol treatment. PTEN mRNA and protein expression was assessed with real-time polymerase chain reaction (PCR) and immunochemistry. To determine whether airway remodeling occurred, the inner airway wall, mucous layer, and smooth muscle areas were each determined using an image analysis system. The lung epithelial cell line 16HBE was used to study the regulation of PTEN expression levels by resveratrol in vitro. Our data demonstrated that resveratrol inhibited OVA-induced airway inflammation and airway remodeling in asthmatic mice. PTEN expression was decreased in the murine asthma model, although the expression of PTEN was restored following treatment with resveratrol. Correlation efficiency analysis showed that PTEN expression was associated with the degree of airway remodeling. Further in vitro studies demonstrated that the inhibition of Sirtuin 1 (SIRT1) activity by a SIRT1 inhibitor and RNA interference decreased PTEN protein expression, while resveratrol attenuated the decreases in PTEN expression induced by the SIRT1 inhibitor. These data suggest the mechanism of the antiasthmatic effects of resveratrol in an OVA-induced murine asthma model, which resulted in the upregulation of PTEN via SIRT1 activation.Key words resveratrol; asthma; phosphatase and tensin homology deleted on chromosome ten; Sirtuin 1 (SIRT1) Asthma is an inflammatory disease that has been verified in clinical practice. Corticosteroids are unique anti-inflammatory agents and represent an important therapy for controlling asthma symptoms.

Background"Phosphatase and tensin homolog deleted on chromosome 10" (PTEN) is mostly considered to be a cancer-related gene, and has been suggested to be a new pathway of pathogenesis of asthma. The purpose of this study was to investigate the effects of the glucocorticoid, dexamethasone, on PTEN regulation.MethodsOVA-challenged mice were used as an asthma model to investigate the effect of dexamethasone on PTEN regulation. Immunohistochemistry was used to detect expression levels of PTEN protein in lung tissues. The human A549 cell line was used to explore the possible mechanism of action of dexamethasone on human PTEN regulation in vitro. A luciferase reporter construct under the control of PTEN promoter was used to confirm transcriptional regulation in response to dexamethasone.ResultsPTEN protein was found to be expressed at low levels in lung tissues in asthmatic mice; but the expression was restored after treatment with dexamethasone. In A549 cells, human PTEN was up-regulated by dexamethasone treatment. The promoter-reporter construct confirmed that dexamethasone could regulate human PTEN transcription. Treatment with the histone deacetylase inhibitor, TSA, could increase PTEN expression in A549 cells, while inhibition of histone acetylase (HAT) by anacardic acid attenuated dexamethasone-induced PTEN expression.ConclusionsBased on the data a new mechanism is proposed where glucocorticoids treat asthma partly through up-regulation of PTEN expression. The in vitro studies also suggest that the PTEN pathway may be involved in human asthma.