Glycogen synthase kinase-3β (GSK-3β), a serine/threonine protein kinase, has been reported to show essential roles in molecular pathophysiology of many diseases. Mitochondrion is a dynamic organelle for producing cellular energy and determining cell fates. Stress-induced translocated GSK-3β may interact with mitochondrial proteins, including PI3K-Akt, PGC-1α, HK II, PKCε, components of respiratory chain, and subunits of mPTP. Mitochondrial pool of GSK-3β has been implicated in mediation of mitochondrial functions. GSK-3β exhibits the regulatory effects on mitochondrial biogenesis, mitochondrial bioenergetics, mitochondrial permeability, mitochondrial motility, and mitochondrial apoptosis. The versatile functions of GSK-3β might be associated with its wide range of substrates. Accumulative evidence demonstrates that GSK-3β inactivation may be potentially developed as the promising strategy in management of many diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Intensive efforts have been made for exploring GSK-3β inhibitors. Natural products provide us a great source for screening new lead compounds in inactivation of GSK-3β. The key roles of GSK-3β in mediation of mitochondrial functions are discussed in this review.

lncRNAs can exert many biological effects in several cancer types. MALAT1 is a kind of lncRNA which is greatly overexpressed in several tumors including non-small cell lung cancer (NSCLC). However, the mechanism of MALAT1 in NSCLC still remains unclear. In our current study, we concentrated on the biological mechanism of MALAT1 in NSCLC. It was observed that MALAT1 was significantly upregulated in five human NSCLC cells including A549, H23, H522, H1299, and H460 cells compared to normal bronchial epithelial cell line 16HBE cells. On the contrary, miR-124 was remarkably downregulated, which indicated a potential negative correlation between miR-124 and MALAT1. MALAT1 inhibition can increase miR-124 expression in A549 and H460 cells. In addition, miR-124 mimics were able to repress MALAT1 expression and miR124 inhibitors can promote MALAT1 levels. Then it was found that shMALAT1 can inhibit NSCLC cell proliferation, colony formation and apoptosis, which can be reversed by miR-124 inhibitors. Bioinformatic analysis predicted the correlation between miR-124 and MALAT1. In addition, STAT3 was found to be a novel mRNA target of miR-124. Downregulation of MALAT1 can inhibit NSCLC development by enhancing miR-124 and decreasing STAT3 expression. We speculated that MALAT1can act as a competing endogenous lncRNA (ceRNA) to modulate miR-124/STAT3 in NSCLC. Taken these together, we revealed that MALAT1/miR-124/STAT3 was involved in NSCLC development.

The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogene in numerous diseases, and aberrant lncRNA PVT1 expression has been associated with the development of cancer. However, the underlying mechanism by which lncRNA PVT1 affects cell invasion in esophageal cancer has been not demonstrated. In the current study, the expression of lncRNA PVT1 was found to be increased in esophageal cancer specimens (n=77) by reverse transcription-quantitative polymerase chain reaction, and was correlated with tumor stage (P=0.009) and metastasis (P<0.001). In vitro, by using transwell assay, upregulation of lncRNA PVT1 promoted the invasion of TE-1 esophageal cancer cells; while downregulation of lncRNA PVT1 inhibited Eca-109 cell invasion. In addition, western blot analysis indicated that upregulation of lncRNA PVT1 may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, lncRNA PVT1 is able to regulate the invasion of esophageal cancer cells by inducing EMT.

LncRNAs can exhibit crucial roles in the development of multiple cancers, including non-small cell lung cancer (NSCLC). Currently, we investigated the role of lncRNA H19 in NSCLC. In our study, it was found that H19 was upregulated in A549 and H1299 cells compared to normal lung epithelial BEAS-2B cells. Meanwhile, we observed that miR-17 was downregulated in NSCLC cell lines. Inhibited H19 can suppress the growth, migration, and invasion of NSCLC cells and bioinformatics search was performed to predict the correlation between H19 and miR-17. Overexpression of miR-17 was able to inhibit the progression of NSCLC cells while reversely miR-17 inhibitors reversed this process. In addition, signal transducers and activators of transcription (STAT3), as an mRNA target of miR-17, was presented in our research. Moreover, we discovered that H19 demonstrated its biological functions via regulating miR-17 and STAT3 in vitro. Silencing H19 greatly increased STAT3 expression by sponging miR-19 in vitro. It was hypothesized that H19 may serve as a competing endogenous RNA (ceRNA) to modulate STAT3 by attaching miR-17 in lung cancer. In summary, our findings indicated that H19/miR-17/STAT3 axis participated in NSCLC development. H19 could be regarded as a significant prognostic biomarker in NSCLC progression.

Long non-coding RNAs (lncRNAs) have played critical roles in a variety of cancers, including non-small cell lung cancer (N SCLC). In our study, we focused on the biological function and clinical significance of lncRNA LINC00968 in NSCLC. It was indicated that LINC00968 was significantly increased in LUAD tissues, LUSC tissues and NSCLC cells compared to their corresponding controls. Inhibition of LINC00968 was able to repress NSCLC growth, migration, and invasion in vitro while upregulation of LINC00968 reversed this process. Additionally, downregulation of LINC00968 induced apoptosis capacity of A549 cell. Apoptosis-related proteins BCL-2 were decreased and BAX was increased by knockdown of LINC00968, respectively. Meanwhile we observed that Wnt signaling pathway was involved in the LINC00968-induced NSCLC progression. Finally, in vivo tumor xenografts were established using A549 cells to detect the function of LINC00968 in NSCLC tumorigenesis. Silencing LINC00968 greatly inhibited NSCLC tumor progression, which was consistent with the in vitro tests. In conclusion, we have uncovered that LINC00968 could be regarded as a novel prognostic biomarker and therapeutic target in NSCLC diagnosis and treatment.

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Background/Aims: Previous studies revealed that circulating (either from plasma or serum) long non-coding RNA may predict the occurrence or prognosis of multiple human malignant tumors. In this study, we mainly explored whether circulating lncRNAs can be utilized as biomarkers predicting the development of human esophageal squamous cell carcinoma (ESCC). Methods: LncRNA microarray was applied to screen the potential biomarkers for ESCC. Each group contained three individual plasma samples. A multi-stage validation and risk score formula detection were used for validation. Results: Eleven dysregulated lncRNAs were obtained after Venny analysis. Further validation in a larger cohort including 205 ESCC patients, 82 patients suffering from esophagus dysplasia and 210 healthy controls confirmed that increased Linc00152, CFLAR-AS1 and POU3F3 might be potential biomarkers for predicting the early progress with an area under curve (AUC) of 0.698, 0.651 and 0.584, respectively. The merged AUC of the three factors and merged with CEA was 0.765 and 0.955, respectively. We also revealed that circulating levels of three lncRNAs were associated with poor post-surgery prognosis of ESCC patients. Conclusions: The three circulating lncRNAs might serve as potential biomarkers for predicting the early occurrence of ESCC.

Polo-like kinase 1 (PLK1), a critical kinase for mitotic progression, is overexpressed in a wide range of cancers. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules and proposed to play important roles in the regulation of tumor progression and invasion. However, the relationship between PLK1 and miRNAs have remained unclear. In the present study, the association between PLK1 and miR-296-5p was investigated. The upregulation of PLK1 mRNA expression levels combined with the downregulation of miR-296-5p levels were detected in both non-small cell lung cancer (NSCLC) tissues and cell lines. Functional studies showed that knockdown of PLK1 by siRNA inhibited NSCLC cells proliferation. Impressively, overexpression of miR-296-5p showed the same phenocopy as the effect of PLK1 knockdown in NSCLC cells, indicating that PLK1 was a major target of miR-296-5p. Furthermore, using western blot analysis and luciferase reporter assay, PLK1 protein expression was proved to be regulated by miR-296-5p through binding to the putative binding sites in its 3'-untranslated region (3'-UTR). Taken together, the present study indicated that miR-296-5p regulated PLK1 expression and could function as a tumor suppressor in NSCLC progression, which provides a potential target for gene therapy of NSCLC.