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Abstract The main cause of gastric cancer (GC)-related death is due to malignant cell unregulated distant metastasis and proliferation. Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) has been shown to play an important role in carcinogenesis and the development of metastasis in several tumors. However, its downstream regulatory mechanism in GC is not well defined. Our study aims to investigate the function and regulatory mechanism of hnRNPA1 in GC. We analyzed the differential expression of hnRNPA1 in gastric cancer and paired adjacent normal tissues in the TCGA database. Kaplan-Meier analysis was employed for survival assessment. The expressions of hnRNPA1 in GC cells were measured by qRT-PCR and Western blot. Transwell assay, CCK8 and colony formation assay were used to detect the effect of hnRNPA1 on the metastasis and proliferation ability of GC cells. Additionally, Western blotting was performed to examine the expression of proteins related to the Wnt/β-catenin signaling pathway as well as epithelial-mesenchymal transition (EMT), while further investigations were carried out to explore potential regulatory mechanisms. The results showed that hnRNPA1 was highly expressed differentially in GC over normal gastric tissue. Knocking down hnRNPA1 inhibited the metastasis and proliferation of human gastric cancer cells. Overexpression of hnRNPA1 significantly enhanced the metastatic potential and proliferative capacity of human GC cells. Further mechanism exploration revealed that knocking down hnRNPA1 inhibited the Wnt/β-catenin signaling pathway and WNT1 inducible signaling pathway protein-2 (WISP2), an activator of the Wnt/β-catenin signaling pathway. Whereas overexpression of hnRNPA1 had the opposite effects. Our results demonstrated that hnRNPA1 promoted metastasis and proliferation of GC cells by activating Wnt/β-catenin signaling pathway via WISP2. hnRNPA1 may serve as a potential biomarker and novel therapeutic targets for GC.

Abstract Background Distant metastasis is the major cause of lung adenocarcinoma (LUAD)-associated mortality. However, molecular mechanisms involved in LUAD metastasis remain to be fully understood. While the role of long non-coding RNAs (lncRNAs) in cancer development, progression, and treatment resistance is being increasingly appreciated, the list of dysregulated lncRNAs that contribute to LUAD pathogenesis is also rapidly expanding. Methods Bioinformatics analysis was conducted to interrogate publicly available LUAD datasets. In situ hybridization and qRT-PCR assays were used to test lncRNA expression in human LUAD tissues and cell lines, respectively. Wound healing as well as transwell migration and invasion assays were employed to examine LUAD cell migration and invasion in vitro. LUAD metastasis was examined using mouse models in vivo. RNA pulldown and RNA immunoprecipitation were carried out to test RNA–protein associations. Cycloheximide-chase assays were performed to monitor protein turnover rates and Western blotting was employed to test protein expression. Results The expression of the lncRNA LINC01559 was commonly upregulated in LUADs, in particular, in those with distant metastasis. High LINC01559 expression was associated with poor outcome of LUAD patients and was potentially an independent prognostic factor. Knockdown of LINC01559 diminished the potential of LUAD cell migration and invasion in vitro and reduced the formation of LUAD metastatic lesions in vivo. Mechanistically, LINC01559 binds to vimentin and prevents its ubiquitination and proteasomal degradation, leading to promotion of LUAD cell migration, invasion, and metastasis. Conclusion LINC01559 plays an important role in LUAD metastasis through stabilizing vimentin. The expression of LINC01559 is potentially an independent prognostic factor of LUAD patients, and LINC01559 targeting may represent a novel avenue for the treatment of late-stage LUAD.

Background: Gastric cancer (GC) ranks as the fifth most prevalent malignancy and stands as the third principal contributor to cancer-related fatalities globally. COL8A1 (collagen type VIII, alpha-1) emerges as a pivotal regulator of tumor progression, but whether COL8A1 drives immune infiltration in GC remains elusive. The aim of our investigation is to elucidate the correlation between COL8A1 and the prognosis as well as immune infiltration in gastric cancer. Methods: The GSE79973 and UALCAN databases were used for assessing the expression of COL8A1. Clinical data was obtained from the TCGA database to analyze the association between the expression of COL8A1 and clinicopathologic features of GC patients. Survival data of GC patients were acquired from the Kaplan-Meier Plotter database. Gene set enrichment analysis was conducted to characterize biological pathways of COL8A1. Immune infiltration analysis was conducted using the CIBERSORT method based on the TCGA database and online analysis within the TIMER2.0 database. Results: We unveiled a noteworthy upregulation of COL8A1 expression across multiple cancer types, particularly in GC. Subsequent analysis underscored a positive linkage between heightened COL8A1 expression and an unfavorable clinical progression in GC patients. Survival analysis indicated that GC patients with elevated COL8A1 expression exhibited a poorer prognosis. Gene enrichment analysis hinted that COL8A1 might participate in physiological processes such as anatomical structure morphogenesis, cell adhesion, focal adhesion, and ECM-receptor interaction et al. in GC. Eventually, we discerned a established association between COL8A1 expression and immune cell infiltration in GC. Conclusion: Our results demonstrated that COL8A1 is a key factor which governs immune cell recruitment to GC, representing a valuable prognostic biomarker in GC patients and potentially playing a crucial role in modulating immune cell infiltration.

ABSTRACTObjective: Obstructive sleep apnea (OSA) is associated with severity of pneumonia; however, the mechanism by which OSA promotes lung cancer progression is unclear.Methods: Twenty-five lung cancer patients were recruited to investigate the relationship between OSA and cancer-associated fibroblast (CAFs) activation. Lung cancer cells (A549) and WI38 fibroblast cells were used to explore the hypoxia-induced TGFβ expression using qPCR, Western blot, and ELISA. Wound healing and transwell assays were performed to evaluate cancer cell migration and invasion. A549 or A549-Luc + WI38 xenograft mouse models were established to detect the intermittent hypoxia (IH) associated with lung tumor growth and epithelial–mesenchymal transition (EMT) in vivo.Results: OSA promotes CAF activation and enrichment in lung cancer patients. Hypoxia (OSA-like treatment) activated TGFβ signaling in both lung cancer cells and fibroblasts, which promoted cancer cell migration and invasion, and enriched CAFs. IH promoted the progression and EMT process of lung cancer xenograft tumor. Co-inoculation of lung cancer cells and fibroblast cells could further promote lung cancer progression.Conclusions: IH promotes lung cancer progression by upregulating TGFβ signaling, promoting lung cancer cell migration, and increasing the CAF activation and proportion of lung tumors.

Abstract The development of resistance to anticancer drugs is believed to cause chemotherapy failure in pancreatic cancer (PC). The efflux of anticancer drugs mediated by ATP-binding cassette (ABC) transporters is a widely accepted mechanism for chemoresistance, but for ABCA subfamily members, which are characterized by their ability to transport lipids and cholesterol, its role in chemoresistance remains unknown. Here we found that the expression of ABCA8, a member of ABCA subfamily transporters, was significantly increased in human PC cells after gemcitabine (GEM) treatment, as well as in established GEM-resistant (Gem-R) PC cells. Importantly, ABCA8 knockdown reversed the chemoresistance phenotype of Gem-R cells, whereas ABCA8 overexpression significantly decreased the sensitivity of human PC cells to GEM, both in vitro and in vivo, demonstrating an important role of ABCA8 in regulating chemosensitivity. Moreover, our results showed that treatment with taurocholic acid (TCA), an endogenous substrate of ABCA8, also induced GEM insensitivity in PC cells. We further demonstrated that ABCA8 mediates the efflux of TCA out of PC cells, and that extracellular TCA activates extracellular signal-regulated kinase (ERK) signaling via the sphingosine 1-phosphate receptor 2 (S1PR2), which is responsible for ABCA8-induced GEM ineffectiveness. Together, these findings reveal a novel TCA-related mechanism of ABCA subfamily transporter-mediated chemoresistance that goes beyond the role of a drug pump and suggest ABCA8 or the TCA-S1RP2-ERK pathway as potential targets for improving the effectiveness of and overcoming the resistance to chemotherapy in PC.

Background/Aim: Cervical cancer (CC) poses a significant threat to women's health and has a relatively poor prognosis due to local invasion and metastasis. It is, therefore, crucial to elucidate the molecular mechanisms of CC metastasis. SNHG3 has been implicated in various tumor metastasis processes, but its involvement in CC has not been thoroughly studied. Our study aimed to investigate the role of SNHG3 in metastasis and elucidate its underlying mechanisms in CC. Materials and Methods: LncRNA SNHG3 expression in CC tissues was analyzed using TCGA and GSE27469 databases. Normal cervical epithelial cells and CC cell lines were used to detect mRNA expression of SNHG3 via quantitative reverse transcription polymerase chain reaction (qRT-PCR). With RNA interference (RNAi) technology, antisense oligonucleotides (ASO) can act on HeLa cells to knockdown target gene expression. The influence of SNHG3 on cell migration and invasion were determined by wound healing and transwell assays. Transcriptome sequencing (RNA-seq) was used to seek abnormally expressed genes between SNHG3 knockdown cells and control cells. The expressions of epithelial-mesenchymal transition (EMT) and Wnt/ß-catenin signaling related proteins were detected using western blot. Results: SNHG3 was obviously up-regulated in CC tissues and cell lines, and ectopic expression of SNHG3 was associated with lymph node metastasis of CC. Knockdown of SNHG3 significantly inhibited cell migration and invasion in CC. Further molecular mechanism studies showed that SNHG3 knockdown could down-regulate the expression of WNT1 Inducible Signaling Pathway Protein 2 (WISP2) so as to inhibit the activation of the Wnt/ß-catenin signaling pathway, and regulated the expression of EMT-related markers, that promoted the protein expression of E-cadherin, as well as decreased the expression of N-cadherin and vimentin. Conclusion: SNHG3 appears to exert a prometastatic effect in CC, as evidenced by inhibition of cell migration and invasion upon SNHG3 knockdown. EMT also appears to be attenuated. Of interest is the down-regulation of WISP2 following SNHG3 knockdown leads to the inactivation of the Wnt/ß-catenin signaling pathway. [ABSTRACT FROM AUTHOR]