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Background: LIN28B plays a critical role in the Warburg effect. However, its underlying mechanism remains elusive. Recently, it has been reported that LIN28B could collaborate with IGF2BP3, which can bind to m6A-modified c-MYC transcripts. Therefore, this study investigated if LIN28B recognises methylated c-MYC mRNA to promote the Warburg effect in gastric cancer. Methods: Effects of LIN28B on gastric cancer were confirmed in vitro and in vivo. On the basis of bioinformatics analysis, the association between LIN28B and c-MYC mRNA was shown using RNA immunoprecipitation (RIP) and luciferase reporter assays. The role of m6A was identified by RNA pull-down assays. We further performed RIP-seq to search for long non-coding RNAs (lncRNAs) participating in the LIN28B binding process. Chromatin immunoprecipitation was used to show the impact of c-MYC on transcription of LIN28B and lncRNAs. Results: LIN28B was identified to stabilize c-MYC mRNA by recognizing m6A. Furthermore, the interaction between c-MYC mRNA and LIN28B is speculated to be supported by LOC101929709, which binds to both LIN28B and IGF2BP3. Functional experiments revealed that LOC101929709 promotes the proliferation, migration and glycolysis of gastric cancer. Mechanistically, LOC101929709 enriched in the cytoplasm helps LIN28B stabilize c-MYC mRNA. Moreover, c-MYC promoted the transcription of both LOC101929709 and LIN28B. Additionally, LOC101929709 also activated the PI3K/AKT pathway. Conclusions: The c-MYC/LOC101929709/LIN28B axis promotes aerobic glycolysis and tumour progression. Thus, LOC101929709 can be a novel potential target for gastric cancer treatment. [ABSTRACT FROM AUTHOR]

SUZ12 is a core component of the polycomb repressive complex 2 (PRC2), which could silence gene transcription by generating trimethylation on lysine 27 residue of histone H3 (H3K27Me3). Meanwhile, SUZ12 has been found to be overexpressed in multiple cancers; however, the clinical significance and molecular mechanisms of SUZ12 controlling gastric cancer cell proliferation and metastasis are unclear. In this study, we found that SUZ12 expression was significantly increased in 64 gastric tumor tissues compared with normal tissues. Additionally, SUZ12 expression was associated with pathological stage, metastasis distance, and shorter overall survival of gastric cancer patients. Knockdown of SUZ12 expression impaired cell proliferation and invasion in vitro, leading to the inhibition of metastasis in vivo. Upregulation of SUZ12 was found to play a key role in gastric cancer cell proliferation and metastasis through the regulation of EMT and KLF2 expression. [ABSTRACT FROM AUTHOR]

Background: Long noncoding RNAs (lncRNAs) have been recently shown to play important regulatory roles in fundamental biological processes, and many of them are deregulated in several human cancers. LncRNA hypoxia-inducible factor 1alpha antisense RNA-2 (HIF1A-AS2) is overexpressed in nonpapillary clear-cell renal carcinomas and involved in cancer progression. Aim: This study was to evaluate the expression of HIF1A-AS2 in gastric cancer (GC) and further explore its biological function in GC cells. Materials and Methods: Quantitative real-time polymerase chain reaction was used to detect the expression level of HIF1A-AS2 in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve (ROC) was constructed to evaluate the diagnostic value of HIF1A-AS2. Besides, tumor cell proliferation was assessed following knockdown of HIF1A-AS2, by MTT and colony formation assay in vitro, and tumor formation assay in a nude mouse model in vivo. Results: The expression of HIF1A-AS2 was upregulated in GC tumorous tissues compared with the adjacent normal tissues ( P < 0.001). Its overexpression was correlated with TNM stages ( P = 0.008), tumor invasion ( P = 0.016), lymph node metastasis ( P = 0.042), and poor prognosis ( P = 0.001). In addition, ROC of HIF1A-AS2 was up to 0.673 (95 % CI 0.596-0.744, P < 0.001). Moreover, knockdown of HIF1A-AS2 expression by siRNA could inhibit cell proliferation in vitro and tumorigenesis in vivo. Conclusions: HIF1A-AS2 is overexpressed in GC and may play a pivotal role in tumor cell proliferation. It can be used as a potential diagnostic and prognostic biomarker for GC. [ABSTRACT FROM AUTHOR]

Kruppel-like factor 2 (KLF2) expression is diminished in many malignancies. However, its expression and role in nonsmall-cell lung cancer (NSCLC) remain unknown. In this study, we found that KLF2 levels were decreased in NSCLC tissues compared with adjacent normal tissues. Its expression level was significantly correlated with TNM stages, tumor size, and lymph node metastasis. Moreover, patients with low levels of KLF2 expression had a relatively poor prognosis. Furthermore, knockdown of KLF2 expression by siRNA could promote cell proliferation, while ectopic expression of KLF2 inhibited cell proliferation and promoted apoptosis in NSCLC cells partly via regulating CDKN1A/p21 and CDKN2B/p15 protein expression. Our findings present that decreased KLF2 could be identified as a poor prognostic biomarker in NSCLC and regulate cell proliferation and apoptosis. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) have emerged as major players in governing fundamental biological processes, and many of which are misregulated in multiple cancers and likely to play a functional role in tumorigenesis. Therefore, identification of cancer-associated lncRNAs and investigation of their biological functions and molecular mechanisms are important for understanding the development and progression of cancer. lncRNA associated with microvascular invasion in HCC (lncRNA MVIH) was found to be generally upregulated in HCC. Moreover, MVIH overexpression could serve as an independent risk factor to predict poor RFS and promote tumor growth and metastasis via activating angiogenesis. However, its biological role and clinical significance in non-small cell lung cancer (NSCLC) development and progression is unknown. In this study, we found that lncRNA MVIH levels were increased in NSCLC tissues compared with adjacent normal tissues. Its expression level was significantly correlated with TNM stages, tumor size, and lymph node metastasis. Moreover, patients with high levels of MVIH expression had a relatively poor prognosis. Furthermore, knockdown of MVIH expression by siRNA could inhibit cell proliferation and invasion, while ectopic expression of MVIH promoted cell proliferation and invasion in NSCLC cells partly via regulating MMP2 and MMP9 protein expression. Our findings present that increased lncRNA MVIH could be identified as a poor prognostic biomarker in NSCLC and regulate cell proliferation and invasion. [ABSTRACT FROM AUTHOR]

Lung cancer is the most frequent cancer in China and all over the world. Recent studies have shown that long noncoding RNAs play critical roles in multiple biological processes including oncogenesis. In this study, we reported a new lncRNA GAS6-AS1 (GAS6 antisense RNA 1), whose expression was downregulated in tumor tissues in 50 patients with non-small cell lung cancer (NSCLC) compared with those in the adjacent normal tissues ( P < 0.001). Furthermore, decreased GAS6-AS1 expression was negatively correlated with lymph node metastasis ( P = 0.032) and advanced tumor node metastasis stage ( P = 0.003). Univariate and multivariate analyses showed that GAS6-AS1 expression served as an independent predictor for overall survival ( P = 0.036). Also, GAS6-AS1 level was inversely correlated with GAS6 (growth-arrest-specific gene6) mRNA level (Pearson’s correlation −0.620). In conclusion, our study demonstrated that altered lncRNA GAS6-AS1 expression might be involved in the development and progression of NSCLC by influencing its host gene and promised to be a potential diagnostic target in patients with NSCLC. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer is the second leading cause of cancer death and remains a major clinical challenge due to poor prognosis and limited treatment options. Long noncoding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and potential therapeutic targets. Although downregulation of lncRNA GAS5 (Growth Arrest-Specific Transcript) in several cancers has been studied, its role in gastric cancer remains unknown. Our studies were designed to investigate the expression, biological role and clinical significance of GAS5 in gastric cancer.Methods: Expression of GAS5 was analyzed in 89 gastric cancer tissues and five gastric cancer cell lines by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Over-expression and RNA interference (RNAi) approaches were used to investigate the biological functions of GAS5. The effect of GAS5 on proliferation was evaluated by MTT and colony formation assays, and cell apoptosis was evaluated by hochest stainning. Gastric cancer cells transfected with pCDNA3.1 -GAS5 were injected into nude mice to study the effect of GAS5 on tumorigenesis in vivo. Protein levels of GAS5 targets were determined by western blot analysis. Differences between groups were tested for significance using Student's t-test (two-tailed).Results: We found that GAS5 expression was markedly downregulated in gastric cancer tissues, and associated with larger tumor size and advanced pathologic stage. Patients with low GAS5 expression level had poorer disease-free survival (DFS; P = 0.001) and overall survival (OS; P < 0.001) than those with high GAS5 expression. Further multivariable Cox regression analysis suggested that decreased GAS5 was an independent prognostic indicator for this disease (P = 0.006, HR = 0.412; 95%CI = 2.218-0.766). Moreover, ectopic expression of GAS5 was demonstrated to decrease gastric cancer cell proliferation and induce apoptosis in vitro and in vivo, while downregulation of endogenous GAS5 could promote cell proliferation. Finally, we found that GAS5 could influence gastric cancer cells proliferation, partly via regulating E2F1 and P21 expression.Conclusion: Our study presents that GAS5 is significantly downregulated in gastric cancer tissues and may represent a new marker of poor prognosis and a potential therapeutic target for gastric cancer intervention. [ABSTRACT FROM AUTHOR]