Expression of beclin 1 in non-small cell lung cancer: an immunohistochemical study

Prognostic value of Beclin 1, EGFR and ALK in non-squamous non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most malignant tumors. The study was carried out to investigate the prognostic value of Beclin 1, EGFR and ALK for this cancer. Patients diagnosed with non-squamous NSCLC and admitted to our hospital from January 2011 to September 2016 were analyzed. Expression of Beclin 1 and mutation of EGFR and ALK were assessed using polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) and analyzed for their relationship with demographic and clinical characteristics of the patients. Multivariate Cox regression models were applied to analyze the risk factors associated with survival and receiver response curves (ROC) were plotted to determine the prognostic value of Beclin 1, EGFR and ALK for patients with non-squamous NSCLC. Compared with adjacent normal tissue, Beclin 1 expression was elevated in the cancer tissue significantly; assessments of EGFR and ALK mutations showed that out of the 480 patients, 233 (48.5%) and 75 (12.6%) patients had EGFR and ALK mutations. Univariate analysis revealed that Beclin 1 level, EGFR and ALK mutations were associated with lymph node metastasis, TNM stage, tumor differentiation and prognosis, but not with gender, age and smoking status. The Kaplan-Meier survival analysis indicated that low Beclin 1 expression and positive EGFR and ALK rearrangements were associated with higher survival rate and longer progress-free survival (PFS). Multivariate Cox regression analysis showed that Beclin 1, EGFR, ALK mutations, tumor differentiation grade, TNM stage and lymph node metastasis were independently associated with PFS. ROC analysis showed that Beclin 1, EGFR and ALK were significant predictors for PFS; the areas under curve (AUC) for Beclin 1, EGFR and ALK were 0.812 (P = 0.018, cut-off value: 1.2), 0.781 (P = 0.011, cut-off value: 15%) and 0.722 (P = 0.010, cut-off value: 11%), respectively, suggesting that they have significant prognostic value for lung cancer patients. Our data indicate that Beclin 1, EGFR and ALK genes are associated with the prognosis of patients with non-squamous NSCLC. High Beclin 1 expression and negative EGFR and ALK mutations predict a poor prognosis with PFS.

Prognostic and clinicopathological significance of Beclin-1 in non-small-cell lung cancer: a meta-analysis

Background

Autophagy plays a key role in the development of non-small-cell lung cancer (NSCLC). Beclin-1 is essential for the initiation and regulation of autophagy. Accumulated studies have investigated the prognostic role of Beclin-1 in NSCLC, but conclusions remain controversial. Therefore, we conducted this meta-analysis to assess the potential significance of Beclin-1 in NSCLC.

Materials and methods

PubMed and Embase databases were searched for eligible studies published before December 31, 2017. Odds ratio (OR) was pooled to evaluate the clinicopathological significance of Beclin-1 in NSCLC. Hazard ratio (HR) was adopted to assess the association of Beclin-1 with overall survival (OS).

Results

Eight studies involving 1,159 patients were included in this meta-analysis. The pooled results showed that high Beclin-1 expression was significantly correlated with earlier tumor grade (OR=0.54, 95% CI: 0.36-0.81, P=0.003), less nodal involvement (OR=0.56, 95% CI: 0.37-0.86, P=0.007), earlier TNM stage (OR=0.62, 95% CI: 0.43-0.89, P=0.010), smaller tumor size (OR=0.54, 95% CI: 0.36-0.81, P=0.003), better differentiation (OR=0.48, 95% CI: 0.36-0.64, P<0.001), and less recurrence (OR=0.24, 95% CI: 0.14-0.41, P<0.001). Moreover, high level of Beclin-1 was significantly associated with better OS in NSCLC (HR=0.41, 95% CI: 0.26-0.64, P<0.001).

Conclusion

Our meta-analysis suggests that high Beclin-1 expression predicts a better clinicopathological status and a better prognosis in NSCLC. Beclin-1 might act as a promising prognostic biomarker for NSCLC.

Autophagy Flux Contributes to Regulation of Components of Eclipta prostrata L. on Cigarette Smoking-Induced Injury of Bronchial Epithelial Cells

Excessive autophagy plays a crucial role in cigarette smoking extract (CSE)-induced inflammation response and oxidative damage of respiratory epithelial cells. The components from Eclipta prostrata L. (CCE) have been shown to be beneficial for CSE-induced epithelial cells injury. However, whether its protection on CSE-stress injury is related to its regulation on autophagy remains still unclear. In this study, CCE, containing mainly wedelolactone of 45.88% and demethylwedelolactone of 23.74%, could improve significantly 10%CSE-induced cell viability of normal human bronchial epithelial (NHBE) cells using CCK-8 kit. We revealed that CCE could remarkably increase autophagic factors Beclin-1, Atg5, ATF4 proteins expression levels and the transformation of LC3-I to LC3-II. Additionally, CCE up-regulated significantly p-p16 and p-p21 phosphorylation levels whereas down-regulated p-p53 in NHBE cells. The changes of typical autolysosom and representative autophagosome in the presence of CCE or/and autophagy inhibitor chloroquine (CQ) were also observed by transmission electron microscopy. These data demonstrated that CCE reduced CSE-induced autophagy flux activation in NHBE cells. The blockade of CCE on autophagy flux contributes to its protection against CSE-induced NHBE cells damage, and CCE is promising to be combination therapeutic molecules to excessive autophagic damage in respiratory diseases.

Promoter methylation of TCF21 may repress autophagy in the progression of lung cancer

Lung cancer is a leading cause of cancer mortality worldwide. Promoter methylation of transcription factor 21 (TCF21) was frequently observed in the early stage of non-small cell lung cancer (NSCLC). However, clinical relevance and molecular functions of TCF21 in NSCLC progression remain unclear. In this study, we analyzed the associations between TCF21 expression and clinicopathological features in 100 patients with NSCLC and revealed the underlying molecular mechanisms of TCF21 methylation on cell viability, apoptosis and invasion of H1299 cells. We found that the expression of TCF21 was significantly regulated by its methylation level in patients with NSCLC and was associated with tumor stage, metastasis and invasion. Demethylation of H1299 cells by 5-aza-2'-deoxycytine (5-Aza) demonstrated that a higher level of TCF21 expression led to remarkable decreases of cell viability and invasion ability but an increase of cell apoptosis. Accordingly, TCF21 knockdown showed converse results to high expression of TCF21. TCF21 knockdown cells exhibited significantly upregulated ATG-9, BECLIN-1, and LC3-I/II expressions but decreased p62 expression compared to wildtype cells. Inhibition of autophagy by 3-methyladenine (3-MA) elevated TCF21 expression and increased cell apoptosis. TCF21 expression is clinically related to the progress of lung cancer and may inhibit autophagy by suppressing ATG-9 and BECLIN-1. In turn, autophagy may also play an important role in regulation TCF21 expression.

Modulation of autophagy in exJSRV-env-transfected cells through the Akt/mTOR and MAPK signaling pathway

The envelope (Env) of Jaagsiekte sheep retrovirus (JSRV) is an oncoprotein of ovine pulmonary adenocarcinoma (OPA). Autophagy is involved in different cancers, but how it is carcinogenic in JSRV Env is unclear. Modulation of autophagy in exJSRV-env-NM-transfected cells through the Akt/mTOR and MAPK signaling pathway was studied, and we observed strong positive labeling of p-Akt, p-mTOR, p-MEK1/2, p-ERK1/2, p-p38 and p-JNK in tumor cells and typical type II pneumocytes in naturally infected OPA lung tissues, which was co-aligned with JSRV-Env positive cells as shown by immunohistochemical and microscopic analysis. Akt/mTOR and MAPK pathways were activated in OPA lung and JSRV-Env transfected NIH 3T3 cells. Decreased Beclin1 and LC3 II/I suggested that autophagy was inhibited in OPA lung and JSRV-Env transfected NIH 3T3 cells. Beclin1 and LC3 II/I increased in JSRV-Env transfected NIH3T3 cells treated with mTOR inhibitor (rapamycin), ERK1/2 inhibitor (PD 98059), p38 inhibitor (SB 203580) and JNK inhibitor (SP 600125), suggesting that Akt/mTOR and MAPK pathways were responsible for JSRV-Env decreased autophagy. In conclusion, JSRV Env decreased autophagy in JSRV-Env transfected NIH3T3 cells through Akt/mTOR and MAPK pathways, in particular, JNK and p38 pathways.

Valproic acid induces autophagy by suppressing the Akt/mTOR pathway in human prostate cancer cells

Previous studies have demonstrated that the chronic administration of valproic acid (VPA) suppresses angiogenesis in vivo; however, the mechanisms implicated in VPA-induced autophagy remain unclear. The current study aimed to assess VPA-induced autophagy in three prostate cancer cell lines (PC3, DU145 and LNCaP), in addition to analyzing the Akt/mammalian target of rapamycin (mTOR) signal pathway. Prostate cancer cell lines were cultured with various doses of VPA. Cell cycle was analyzed using flow cytometry, and autophagy markers [1A/1B-light chain 3 (LC3)-II and Beclin-1] were examined using transmission electron microscopy, fluorescent microscopy and western blotting. Activation of the Akt/mTOR signal pathway was also assessed by western blotting. The results demonstrated that VPA induced autophagosomes and suppressed the Akt/mTOR signal pathway. This was confirmed by detection of increased LC3-II and Beclin-1 in VPA-treated cells compared with untreated controls. Phosphorylated forms of Akt (PC3, P=0.048; DU145, P=0.045; LNCaP, P=0.039) and mTOR (PC3, P=0.012; DU145, P=0.41; LNCaP, P=0.35) were significantly reduced following VPA treatment. These results suggest that VPA may function as a histone deacetylase inhibitor, suppressing the growth of prostate cancer cells by modulating autophagy pathways, including inhibition of the Akt/mTOR pathway. Further experiments are required to determine the significance of all involved pathways regarding VPA-induced growth inhibition.