FOXO transcription factors are key tumor suppressors in mammalian cells. Until now, suppression of FOXOs in cancer cells was thought to be mainly due to activation of multiple onco-kinases by a phosphorylation-ubiquitylation-mediated cascade. Therefore, it was speculated that inhibition of FOXO proteins would naturally occur through a multiple step post-translational process. However, whether cancer cells may downregulate FOXO protein via an alternative regulatory mechanism is unclear. In the current study, we report that expression of miR-96 was markedly upregulated in breast cancer cells and breast cancer tissues compared with normal breast epithelial cells (NBEC) and normal breast tissues. Ectopic expression of miR-96 induced the proliferation and anchorage-independent growth of breast cancer cells, while inhibition of miR-96 reduced this effect. Furthermore, upregulation of miR-96 in breast cancer cells resulted in modulation of their entry into the G1/S transitional phase, which was caused by downregulation of cyclin-dependent kinase (CDK) inhibitors, p27Kip1 and p21Cip1, and upregulation of the cell-cycle regulator cyclin D1. Moreover, we demonstrated that miR-96 downregulated FOXO3a expression by directly targeting the FOXO3a 3′-untranslated region. Taken together, our results suggest that miR-96 may play an important role in promoting proliferation of human breast cancer cells and present a novel mechanism of miRNA-mediated direct suppression of FOXO3a expression in cancer cells.
Astrocyte elevated gene 1 (AEG-1), a novel oncoprotein, has been implicated in oncogenesis and cancer progression in various types of human cancers. The clinical significance and biological role of AEG-1 in non-small cell lung cancer (NSCLC), however, remain unclear. In the present study, we found that the expression of AEG-1 was markedly up-regulated in NSCLC cell lines and NSCLC tissues at the level of both transcription and translation. Ectopically expressed AEG-1 enhanced the migratory and invasive abilities of NSCLC cells, whereas knockdown of endogenous AEG-1 by specific shRNAs significantly inhibited these abilities. The function of AEG-1 on metastasis modulation was associated with the activation of the PI3K-Akt and NF-kappaB signalling pathways. Furthermore, we showed high expression of AEG-1 in 99/200 (49.5%) paraffin-embedded archival NSCLC specimens. Moreover, statistical analysis displayed a significant correlation in AEG-1 expression with the clinical stage (p < 0.001), T classification (p = 0.001), N classification (p = 0.015), distant metastasis (p = 0.004) and differentiation (p = 0.027). Patients with higher AEG-1 expression had an overall shorter survival time, whereas patients with lower expression of AEG-1 had a better survival time. Multivariate analysis suggested that AEG-1 expression might be an independent prognostic indicator for the survival of NSCLC patients. Taken together, our results suggest that elevated expression of AEG-1 plays an important role in the aggressiveness of NSCLC, leading to a poor clinical outcome.
Background: Programmed cell death protein-1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have remarkable clinical efficacy in the treatment of non-small cell lung cancer (NSCLC); however, the breakdown of immune escape causes a variety of immune-related adverse events (irAEs). With the increasing use of PD-1/PD-L1 inhibitors alone or in combination with other therapies, awareness and management of irAEs have become more important. We aimed to assess the incidence and nature of irAEs associated with PD-1 and PD-L1 inhibitors for NSCLC. Methods: Articles from the MEDLINE, EMBASE, and Cochrane databases were searched through December 2017. The incidence of overall and organ-specific irAEs was investigated in all clinical trials with nivolumab, pembrolizumab, atezolimumab, durvalumab, and avelumab as single agents for treatment of NSCLC. We calculated the pooled incidence using R software with package Meta. Results: Sixteen trials were included in the meta-analysis: 10 trials with PD-1 inhibitors (3734 patients) and 6 trials with PD-L1 inhibitors (2474 patients). The overall incidence of irAEs was 22% (95% confidence interval [CI], 17-28) for all grades and 4% (95% CI, 2-6) for high-grade irAEs. The frequency of irAEs varied based on drug type and organ, and patients treated with PD-1 inhibitors had an increased rate of any grade and highgrade irAEs compared with patients who received PD-L1 inhibitors. Organ-specific irAEs were most frequently observed in, in decreasing order, the endocrine system, skin, pulmonary tract, and gastrointestinal tract. The total number of patients whose death was attributed to irAEs was 14 (0.34%), and most (79%) of these patients died because of pneumonitis. The median time to the onset of irAEs after the initiation of treatment was 10 weeks (interquartile range, 6-19.5 weeks) and varied depending on the organ system involved. Conclusions: The specificity of irAEs was closely associated with the mechanism of PD-1/PD-L1 antibodies involved in restarting anticancer immune attacks. Comprehensive understanding, timely detection, and effective management could improve the compliance of patients and guide the interruption of treatment.
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