A novel antisense lncRNA NT5E promotes progression by modulating the expression of SYNCRIP and predicts a poor prognosis in pancreatic cancer.

A novel antisense lncRNA NT5E was identified in a previous microarray that was clearly up-regulated in pancreatic cancer (PC) tissues. However, its biological function remains unclear. Thus, we aimed to explore its function and clinical significance in PC. The lncNT5E expression was determined in PC specimens and cell lines. In vitro and in vivo studies detected the impact of lncNT5E depletion on PC cell proliferation, migration and invasion. Western blotting investigated the epithelial-mesenchymal transition (EMT) markers. The interaction between lncNT5E and the promoter region of SYNCRIP was detected by dual-luciferase reporter assay. The role of lncNT5E in modulating SYNCRIP was investigated in vitro. Our results showed that lncNT5E was significantly up-regulated in PC tissues and cell lines and associated with poor prognosis. LncNT5E depletion inhibited PC cell proliferation, migration, invasion and EMT in vitro and caused tumorigenesis arrest in vivo. Furthermore, SYNCRIP knockdown had effects similar to those of lncNT5E depletion. A significant positive relationship was observed between lncNT5E and SYNCRIP. Moreover, the dual-luciferase reporter assays indicated that lncNT5E depletion significantly inhibited SYNCRIP promoter activity. Importantly, the malignant phenotypes of lncNT5E depletion were rescued by overexpressing SYNCRIP. In conclusion, lncNT5E predicts poor prognosis and promotes PC progression by modulating SYNCRIP expression.

Zhang P ，Cao M ，Zhang Y ，Xu L ，Meng F ，Wu X ，Xia T ，Chen Q ，Shi G ，Wu P ，Chen L ，Lu Z ，Yin J ，Cai B ，Cao S ，Miao Y ，Jiang K ... -  《-》

RBIS regulates ribosome biogenesis to affect progression in lung adenocarcinoma.

Increased ribosome biogenesis is required for tumor growth. In this study, we investigated the function and underlying molecular mechanism of ribosome biogenesis factor (RBIS) in the progression of non-small cell lung cancer (NSCLC). In our study, we conducted a comprehensive analysis to identify key genes implicated in ribosome biogenesis by leveraging a Gene Set Enrichment Analysis (GSEA) dataset. Subsequently, we performed a comparative analysis of gene expression profiles by utilizing data from the Gene Expression Omnibus (GEO) datasets to ascertain differentially expressed genes (DEGs) between cancerous and adjacent non-cancerous tissues. Through the intersection of gene sets derived from GSEA and GEO, we identified a cohort of ribosome-associated genes that might exert a substantial influence on the progression of lung adenocarcinoma. Following an extensive literature review, we have identified the RBIS gene as an interesting candidate for further investigation. To elucidate the in vitro functional role of RBIS, several assays was employed, including the Transwell migration and invasion assay, wound healing assay, Cell Counting Kit-8 (CCK-8) proliferation assay, and colony formation assay. Subcutaneous and tail vein injection-based lung metastasis xenograft tumor models were used in evaluating the tumorigenic potential, growth, and metastatic spread of lung cancer cells. Flow cytometry analysis was employed to investigate cell cycle distribution and apoptotic rates. Additionally, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was utilized to quantify the mRNA expression levels of genes. To comprehensively assess the translational efficiency of nascent proteins, we employed polysome profiling analysis to provide insights into the cellular translational landscape. Furthermore, we quantified global protein synthesis using a fluorescence-based assay to measure protein synthesis rates. The immunofluorescence technology was utilized to study the subcellular reorganization of the nucleolus. We conducted co-immunoprecipitation (Co-IP) assays followed by Western blot analysis to identify potential proteins interacted with RBIS. The half maximal inhibitory concentration (IC50) was used for evaluating the chemosensitivity of lung cancer cells to gemcitabine. Additionally, the colony formation assay was employed to assess the survival and proliferative capacity post-treatment of gemcitabine. The database analysis showed that RBIS was upregulated in lung adenocarcinoma, and its high expression was associated with poor prognosis; Knockdown of RBIS significantly inhibited NSCLC cell migration, invasion and proliferation in vitro and xenograft tumor growth and metastasis in vivo. Additionally, knockdown of RBIS led to G0/G1 phase arrest and significantly increased apoptosis in lung adenocarcinoma cells. Mechanistically, downregulation of RBIS significantly decreased the expression of 47S ribosomal RNA (rRNA), a component associated with ribosome assembly. Polysome profiling analysis indicated that RBIS knockdown affected protein translation efficiency, and global protein synthesis assay further verified that RBIS knockdown inhibited synthesis of newborn proteins. Additionally, the ribosomal biogenesis-targeting drugs CX-5461 and the loss of RBIS exhibited synergistic effects in inhibiting cell cycle progression and inducing apoptosis. Furthermore, the ribosomal maturation factor GNL2 was identified as the key downstream regulator of RBIS in ribosome biogenesis. Notably, knockdown of RBIS substantially increased the sensitivity of lung adenocarcinoma cells to the chemotherapeutic drug gemcitabine, highlighting its l role in chemotherapy. Collectively, these studies suggested the close involvement of RBIS in the progression of lung adenocarcinoma, providing new insights for targeted therapeutic interventions involving ribosomes.

Pan H ，Liao L ，Xu S ，Xu Y ，Chai W ，Liu X ，Li J ，Cao Y ，Sun L ，Liu Q ，Yan M ... -  《Journal of Translational Medicine》

YAP1 Overexpression Enhances the Aerobic Glycolysis Process via Suppression of EGLN2 in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive diseases and has remarkably high mortality rates. In recent years, altered metabolism has been shown to contribute to the maintenance of pancreatic cancer malignancies. However, the molecular mechanism underlying glucose metabolism reprogramming remains elusive. The aim of this study was to elucidate the role of Yes-associated protein (YAP1), an important effector of the Hippo pathway, in the regulation of aerobic glycolysis in pancreatic cancer. Moreover, the contributions of YAP1 and its associated glycolytic enzymes to prognosis were assessed via The Cancer Genome Atlas (TCGA) dataset. YAP1 expression was silenced by short hairpin RNA (shRNA), and its effects on glycolytic activity and mitochondrial respiration were analysed via Agilent Seahorse XF Analysers. The effects of YAP1 on hypoxia-inducible factor-1α (HIF-1α) and its transcriptional activity on glycolytic genes were examined via shRNA-mediated silencing of YAP1. The underlying mechanism by which YAP1 controls the HIF-1α protein level was analysed by exploring the interaction between YAP1 and egg-laying-defective nine family (EGLN) members, which are well-established regulators of the HIF-1α protein level. Finally, the effects of YAP1, EGLN and glycolytic genes on prognosis were analysed via TCGA dataset. We found that silencing YAP1 expression inhibited anabolic glycolysis in pancreatic cancer cells. YAP1 was demonstrated to regulate the HIF-1α protein level, transcriptional activity and the expression of HIF-1α-targeted glycolytic genes. In-depth analysis demonstrated that EGLN2, a modulator of the HIF-1α protein level, was a direct target of YAP1. Low EGLN2 expression was associated with a poor prognosis. By analysing TCGA dataset and performing immunohistochemical staining, we demonstrated that YAP1 expression was negatively correlated with EGLN2 expression at the mRNA level and protein levels. The present study demonstrated that YAP1 positively regulates aerobic glycolysis by inhibiting EGLN2 expression, which results in an increased HIF-1α protein level and transcriptional activity. YAP1 was positively regulated and significantly correlated with HIF-1α-targeted glycolytic genes, including glucose transporter type 1(GLUT1), hexokinase2 (HK2) and lactate dehydrogenase A (LDHA). Elevated YAP1 expression and concomitant downregulation of EGLN2 contributed to poor survival in patients with pancreatic cancer. Our results suggest that YAP1 may be a promising predictive marker and treatment target for human pancreatic cancer.

Hu P ，Dou R ，Qi Z ，Liu G ，Su Y ... -  《-》

The miR-1269a/PCDHGA9/CXCR4/β-catenin pathway promotes colorectal cancer invasion and metastasis.

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. This research focuses on investigating the impact and underlying molecular mechanisms of protocadherin gamma subfamily A, 9 (PCDHGA9) on the invasion and metastasis of CRC, aiming to identify more precise molecular markers for the diagnosis and prognosis of CRC. PCDHGA9 expression was detected using quantitative real-time quantitative polymerase chain reaction (RT-qPCR) in 63 pairs of colorectal cancer tissues. Differential gene expression from high-throughput sequencing was analyzed using ingenuity pathway analysis (IPA) to explore the biological functions of PCDHGA9 and its potential regulated genes. Bioinformatics tools were employed to explore potential upstream regulatory microRNAs of PCDHGA9. Dual-luciferase assays were performed to demonstrate the regulation between PCDHGA9 and miR-1269a. Protein mass spectrometry suggested an interaction between PCDHGA9 and HOXA1. JASPAR predicted that HOXA1 may act as a transcription factor of CXCR4. Coimmunoprecipitation, dual-luciferase assays, and nuclear-cytoplasmic fractionation experiments confirmed the molecular mechanism involving PCDHGA9, CXCR4, HOXA1, and β-catenin. Transwell, wound healing, and western blot assays were conducted to confirm the impact of PCDHGA9, miR-1269a, and CXCR4 on the invasion, metastasis, and epithelial-mesenchymal transition (EMT) functions of CRC cells in in vitro experiments. A whole-body fluorescence imaging system was used to evaluate the combined impact of miR-1269a and PCDHGA9 on the invasion and metastasis of CRC in in vivo experiments. The expression of PCDHGA9 was found to be lower in CRC tissues compared with their corresponding adjacent tissues. Low expression of PCDHGA9 potentially correlated with worse prognosis and increased chances of invasion and metastasis in CRC. miR-1269a was highly expressed in CRC tissues and acted as a negative regulator for PCDHGA9, promoting invasion, migration, and EMT of CRC cells. PCDHGA9's interaction with HOXA1 downregulated CXCR4, a transcription factor, leading to accumulation of β-catenin and further promoting invasion, migration, and EMT of CRC cells. PCDHGA9, acting as a tumor suppressor, is downregulated by miR-1269a. The low level of PCDHGA9 activates the Wnt/β-catenin pathway by releasing its interaction with HOXA1, promoting the expression of CXCR4, and causing invasion, migration, and EMT in CRC.

Mei H ，Luo Q ，Weng J ，Hao J ，Cai J ，Zhou R ，Bian C ，Ye Y ，Luo S ，Wen Y ... -  《-》

Expression profile and function of secretogranin V, and its effects on the malignant behavior of esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is recognized as one of the most aggressive cancers with a poor prognosis. Global expression profiling was conducted on primary ESCC tissues with distant metastases. We investigated the identification of secretogranin V (SCG5) as a promising biomarker for the detection and assessment of ESCC. SCG5 transcription levels were evaluated in 21 ESCC cell lines. Small interfering RNA-mediated knockdown experiments validated SCG5's roles in cell invasion, proliferation, and migration. We utilized a mouse subcutaneous xenograft model to assess tumor growth. SCG5 expression was measured in 164 ESCC tissues by quantitative reverse transcription quantitative polymerase chain reaction, and its association with clinicopathological parameters was investigated. SCG5 protein levels were assessed in surgically resected tissues from 177 patients with ESCC using a tissue microarray. The mRNA expression levels of SCG5 varied widely in ESCC cell lines. The in vitro cell invasion, proliferation, and migration of ESCC cells were suppressed by the knockdown of SCG5. Mouse xenograft models revealed that tumor growth was reduced by small interfering RNA-mediated SCG5 knockdown. Analysis of clinical samples demonstrated that SCG5 mRNA was expressed in ESCC compared to adjacent normal esophageal tissues. High SCG5 mRNA expression was linked to significant decreases in overall and disease-specific survival. Furthermore, SCG5 protein expression was linked to a decrease in disease-specific survival and disease-free survival. The expression of the SCG5 was significantly associated with disease-specific survival, suggesting that SCG5 may play a significant role as a diagnostic and prognostic biomarker for ESCC.

Hamrah MH ，Kanda M ，Sato Y ，Zhu H ，Bayasgalan T ，Garza F ，Shinozuka T ，Ito Y ，Sasahara M ，Shimizu D ，Umeda S ，Takami H ，Hattori N ，Hayashi M ，Tanaka C ，Kodera Y ... -  《-》