OBJECTIVE: To explore the potential role of mRNA m7G modification in the pathogenesis of human adenocarcinoma of esophagogastric junction (AEG). METHODS: Pathological tissue specimens from four AEG patients who underwent surgical treatment at the People's Hospital Affiliated to Jiangsu University between 2018 and 2019 were selected. Tumor tissues and adjacent normal tissues were collected from these patients. RNA was extracted from both tissue types and subjected to m7G methylated RNA immunoprecipitation sequencing (m7G-MeRIP-seq) to analyze the patterns of m7G modification, the characteristics of differential m7G modification sites, the differentially expressed mRNA, and the correlation between m7G modification and mRNA expression levels. Differential m7G-modified genes (MSH6, BRCA1, and SOX9) were further validated using methylated RNA immunoprecipitation quantitative PCR (MeRIP-qPCR), while the expression of METTL1 and WDR4 genes was examined by real-time quantitative PCR (RT-qPCR). This study was approved by the Medical Ethics Committee of the People's Hospital Affiliated to Jiangsu University (Ethics No. 20150083). RESULTS: m7G-MeRIP-seq analysis revealed that m7G modifications in both AEG and adjacent normal tissues were predominantly located in the GC-rich region surrounding the internal start codon of mRNA. Differential m7G modification sites between the two groups were closely associated with cancer-related genes. mRNA library analysis showed that differentially expressed mRNA were predominantly upregulated in AEG tissues and downregulated in adjacent normal tissues. Cross-analysis indicated that genes with hypermethylation tended to exhibit upregulated expression, while genes with hypomethylation were typically downregulated in AEG tissues. MeRIP-qPCR validation confirmed that the mRNA expression of MSH6, BRCA1, and SOX9 were significantly upregulated in AEG tissues compared to adjacent normal tissues (AEG vs. normal, P < 0.05). RT-qPCR results demonstrated that the mRNA expression levels of METTL1 and WDR4 were also upregulated in AEG tissues (AEG vs. normal, P < 0.000 5). CONCLUSION These findings suggest that mRNA m7G modification plays a significant role in the development of AEG. Furthermore, proteins as METTL1 and WDR4 may facilitate AEG progression by regulating mRNA m7G modification. These results provide valuable insights into the molecular mechanisms underlying AEG and may inform future therapeutic strategies for this malignancy.
Humans ; RNA, Messenger/metabolism* ; Adenocarcinoma/pathology* ; Esophagogastric Junction/metabolism* ; Esophageal Neoplasms/metabolism* ; Gene Expression Regulation, Neoplastic ; Female ; Male ; Middle Aged ; DNA Methylation ; Methyltransferases/metabolism* ; Stomach Neoplasms/genetics*

Pristimerin, which is one of the compounds present in Celastraceae and Hippocrateaceae, has antitumor effects. However, its mechanism of action in esophageal squamous cell carcinoma (ESCC) remains unclear. This study aims to investigate the efficacy and mechanism of pristimerin on ESCC in vitro and in vivo. The inhibitory effect of pristimerin on cell growth was assessed using trypan blue exclusion and colony formation assays. Cell apoptosis was evaluated by flow cytometry. Gene and protein expressions were analyzed through quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry. RNA sequencing (RNA-Seq) was employed to identify significantly differentially expressed genes (DEGs). Cell transfection and RNA interference assays were utilized to examine the role of key proteins in pristimerin?s effect. Xenograft models were established to evaluate the antitumor efficiency of pristimerin in vivo. Pristimerin inhibited cell growth and induced apoptosis in ESCC cells. Upregulation of Noxa was crucial for pristimerin-induced apoptosis. Pristimerin activated the Forkhead box O3a (FoxO3a) signaling pathway and triggered FoxO3a recruitment to the Noxa promoter, leading to Noxa transcription. Blocking FoxO3a reversed pristimerin-induced Noxa upregulation and cell apoptosis. Pristimerin treatment suppressed xenograft tumors in nude mice, but these effects were largely negated in Noxa-KO tumors. Furthermore, the chemosensitization effects of pristimerin in vitro and in vivo were mediated by Noxa. This study demonstrates that pristimerin exerts an antitumor effect on ESCC by inducing AKT/FoxO3a-mediated Noxa upregulation. These findings suggest that pristimerin may serve as a potent anticancer agent for ESCC treatment.
Forkhead Box Protein O3/genetics* ; Humans ; Apoptosis/drug effects* ; Esophageal Squamous Cell Carcinoma/physiopathology* ; Esophageal Neoplasms/physiopathology* ; Pentacyclic Triterpenes ; Animals ; Cell Line, Tumor ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Mice ; Signal Transduction/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Triterpenes/pharmacology* ; Xenograft Model Antitumor Assays ; Mice, Inbred BALB C ; Male ; Gene Expression Regulation, Neoplastic/drug effects*

BACKGROUND: The transcription factor POU2F1 regulates the expression levels of microRNAs in neoplasia. However, the miR-29b1/a cluster modulated by POU2F1 in gastric cancer (GC) remains unknown. METHODS: Gene expression in GC cells was evaluated using reverse-transcription polymerase chain reaction (PCR), western blotting, immunohistochemistry, and RNA in situ hybridization. Co-immunoprecipitation was performed to evaluate protein interactions. Transwell migration and invasion assays were performed to investigate the biological behavior of GC cells. MiR-29b1/a cluster promoter analysis and luciferase activity assay for the 3'-UTR study were performed in GC cells. In vivo tumor metastasis was evaluated in nude mice. RESULTS: POU2F1 is overexpressed in GC cell lines and binds to the miR-29b1/a cluster promoter. POU2F1 is upregulated, whereas mature miR-29b-3p and miR-29a-3p are downregulated in GC tissues. POU2F1 promotes GC metastasis by inhibiting miR-29b-3p or miR-29a-3p expression in vitro and in vivo . Furthermore, PIK3R1 and/or PIK3R3 are direct targets of miR-29b-3p and/or miR-29a-3p , and the ectopic expression of PIK3R1 or PIK3R3 reverses the suppressive effect of mature miR-29b-3p and/or miR-29a-3p on GC cell metastasis and invasion. Additionally, the interaction of PIK3R1 with PIK3R3 promotes migration and invasion, and miR-29b-3p , miR-29a-3p , PIK3R1 , and PIK3R3 regulate migration and invasion via the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway in GC cells. In addition, POU2F1 , PIK3R1 , and PIK3R3 expression levels negatively correlated with miR-29b-3p and miR-29a-3p expression levels in GC tissue samples. CONCLUSIONS The POU2F1 - miR-29b-3p / miR-29a-3p-PIK3R1 / PIK3R1 signaling axis regulates tumor progression and may be a promising therapeutic target for GC.
MicroRNAs/metabolism* ; Humans ; Stomach Neoplasms/pathology* ; Cell Line, Tumor ; Cell Movement/physiology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Animals ; Mice ; Octamer Transcription Factor-1/metabolism* ; Mice, Nude ; Class Ia Phosphatidylinositol 3-Kinase/metabolism* ; Neoplasm Invasiveness ; Gene Expression Regulation, Neoplastic/genetics* ; Male ; Immunohistochemistry ; Female

BACKGROUND: Growing evidence suggests that long non-coding RNAs (lncRNAs) exert pivotal roles in fostering chemoresistance across diverse tumors. Nevertheless, the precise involvement of lncRNAs in modulating chemoresistance within the context of gallbladder cancer (GBC) remains obscure. This study aimed to uncover how lncRNAs regulate chemoresistance in gallbladder cancer, offering potential targets to overcome drug resistance. METHODS: To elucidate the relationship between gemcitabine sensitivity and small nucleolar RNA host gene 1 ( SNHG1 ) expression, we utilized publicly available GBC databases, GBC tissues from Renji Hospital collected between January 2017 and December 2019, as well as GBC cell lines. The assessment of SNHG1, miR-23b-3p, and phosphatase and tensin homolog (PTEN) expression was performed using in situ  hybridization, quantitative real-time polymerase chain reaction, and western blotting. The cell counting kit-8 (CCK-8) assay was used to quantify the cell viability. Furthermore, a GBC xenograft model was employed to evaluate the impact of SNHG1 on the therapeutic efficacy of gemcitabine. Receiver operating characteristic (ROC) curve analyses were executed to assess the specificity and sensitivity of SNHG1. RESULTS: Our analyses revealed an inverse correlation between the lncRNA SNHG1 and gemcitabine resistance across genomics of drug sensitivity in cancer (GDSC) and Gene Expression Omnibus (GEO) datasets, GBC cell lines, and patients. Gain-of-function investigations underscored that SNHG1 heightened the gemcitabine sensitivity of GBC cells in both in vitro and in vivo  settings. Mechanistic explorations illuminated that SNHG1 could activate PTEN -a commonly suppressed tumor suppressor gene in cancers-thereby curbing the development of gemcitabine resistance in GBC cells. Notably, microRNA (miRNA) target prediction algorithms unveiled the presence of miR-23b-3p binding sites within SNHG1 and the 3'-untranslated region (UTR) of PTEN . Moreover, SNHG1 acted as a sponge for miR-23b-3p, competitively binding to the 3'-UTR of PTEN , thereby amplifying PTEN expression and heightening the susceptibility of GBC cells to gemcitabine. CONCLUSION The SNHG1/miR-23b-3p/PTEN axis emerges as a pivotal regulator of gemcitabine sensitivity in GBC cells, holding potential as a promising therapeutic target for managing GBC patients.
Humans ; Deoxycytidine/pharmacology* ; PTEN Phosphohydrolase/genetics* ; Gemcitabine ; RNA, Long Noncoding/metabolism* ; MicroRNAs/genetics* ; Gallbladder Neoplasms/genetics* ; Cell Line, Tumor ; Animals ; Mice ; Drug Resistance, Neoplasm/genetics* ; Mice, Nude ; Antimetabolites, Antineoplastic ; Gene Expression Regulation, Neoplastic

Noncoding RNAs (ncRNAs) are a class of RNA molecules with little or no protein-coding potential. Emerging evidence indicates that ncRNAs are frequently dysregulated and play pivotal roles in the pathogenesis of pancreatic cancer. Their aberrant expression can arise from chromosomal abnormalities, dysregulated transcriptional control, and epigenetic modifications. ncRNAs function as protein scaffolds or molecular decoys to modulate interactions between proteins and other biomolecules, thereby regulating gene expression and contributing to pancreatic cancer progression. In this review, we summarize the mechanisms underlying ncRNA dysregulation in pancreatic cancer, emphasize the biological significance of ncRNA-protein interactions, and highlight their clinical relevance. A deeper understanding of ncRNA-protein interactions is essential to elucidate molecular mechanisms and advance translational research in pancreatic cancer.
Humans ; Pancreatic Neoplasms/metabolism* ; RNA, Untranslated/metabolism* ; Gene Expression Regulation, Neoplastic/genetics*

OBJECTIVE: miR-34c-3p is down-regulated in nasopharyngeal carcinoma (NPC). The biological role of miR-34c-3p in NPC and its underlying mechanisms are unknown and were explored in this study. METHODS: Flow cytometry and immunohistochemical staining were employed to detect cluster of differentiation 86 (CD86) and cluster of differentiation 206 (CD206) expression; quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were employed to examine mRNA expression and protein levels; cell counting kit-8 (CCK8) and transwell assays were employed to assess cell proliferation, migration, and invasion; and hematoxylin-eosin (HE) staining was employed to assess pathological changes in tumor tissues. RESULTS: Our results revealed that the miR-34c-3p mimic markedly inhibited M2 polarization of macrophages by targeting SLC7A11, and M2 macrophages transfected with the miR-34c-3p mimic inhibited the proliferation, migration, and invasion of NPC cells. The in vivo experiments further confirmed that miR-34c-3p mimics blocked tumor growth and reduced inflammatory infiltration in tumor tissues. CONCLUSION This study provides novel insights into the pathogenesis of NPC and a new treatment strategy.
MicroRNAs/metabolism* ; Nasopharyngeal Carcinoma/genetics* ; Humans ; Animals ; Nasopharyngeal Neoplasms/genetics* ; Macrophages/physiology* ; Cell Line, Tumor ; Mice ; Cell Proliferation ; Mice, Inbred BALB C ; Cell Movement ; Male ; Gene Expression Regulation, Neoplastic ; Mice, Nude ; Female

OBJECTIVE: To explore the correlation between chromosome 8 open reading frame 76 (C8orf76) and cyclin-dependent kinase 4 (CDK4) and the potential predictive effect of C8orf76 and CDK4 on the prognosis of colorectal cancer (CRC). METHODS: We constructed a protein-protein interaction network of C8orf76-related genes and analyzed the prognostic signatures of C8orf76 and CDK4. Clinicopathological features of C8orf76 and CDK4 were visualized using a nomogram. RESULTS: C8orf76 and CDK4 levels were positively correlated in two independent human CRC cohorts ( n = 83 and n = 597). A consistent positive correlation was observed between C8orf76 and CDK4 expression in the CRC cell lines. The nomogram included prognostic genes (C8orf76 and CDK4) and pathological N and M stages. The concordance index (C-index) in our cohort was 0.776, which suggests that the ability of the indicators to predict the overall survival of patients with CRC in our cohort was strong. CONCLUSION We found that C8orf76 was positively correlated with CDK4 in both the cohorts as well as in CRC cell lines. Therefore, C8orf76 and CDK4 can be used as potential biomarkers to predict the prognosis of CRC.
Humans ; Colorectal Neoplasms/diagnosis* ; Cyclin-Dependent Kinase 4/metabolism* ; Prognosis ; Male ; Female ; Middle Aged ; Biomarkers, Tumor/genetics* ; Aged ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic

OBJECTIVES: To investigate the role of nucleolar pre-rRNA processing protein NIP7 (NIP7) in maintaining the malignant phenotype of anaplastic thyroid cancer (ATC) and its molecular mechanisms. METHODS: NIP7 expression in ATC tissues and its gene knock-out effects in ATC cells were analyzed using gene expression microarray (GSE33630), proteome database (IPX0008941000) and the Dependency Map database, respectively. Expression and localization of NIP7 in normal thyroid cells, papillary thyroid cancer cells, and ATC cells were detected by Western blotting. Small interfering RNA (siRNA) was transfected into ATC cells, and the knockdown efficiency of NIP7 was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. Cell proliferation was assessed by CCK-8 assay, colony formation was evaluated by colony formation assay, and tumor growth was assessed by xenograft tumor model in nude mice. SUnSET (surface sensing of translation) assay combined with co-immunoprecipitation were employed to evaluate the effect of NIP7 silencing on ubiquitin-conjugating enzyme E2 C (UBE2C) translation. Finally, gene set enrichment analysis was used to identify shared pathways of NIP7 and UBE2C, which were validated by qRT-PCR. RESULTS: Compared with normal tissues and papillary thyroid cancer, NIP7 was significantly upregulated in ATC tissues, and had a gene knock-out fitness effect on different ATC cell lines. The relative protein levels of NIP7 in ATC cells were significantly higher than those in normal thyroid follicular cells, and the protein was mainly expressed in the nucleus. NIP7 silencing significantly inhibited cell proliferation and reduced colony formation. Xenograft tumor model showed that NIP7 knockdown significantly slowed down the growth of ATC xenograft, and the tumor volume and weight were significantly lower than those in the control group (all P<0.05). NIP7 silencing downregulated the protein level of UBE2C, but did not affect the expression of UBE2C mRNA. Compared to the control group, UBE2C silencing significantly inhibited ATC cells proliferation (P<0.01) and colony formation (P<0.05). UBE2C overexpression reversed the proliferation-inhibitory effect induced by NIP7 silencing (P<0.01). Gene set enrichment analysis indicated that NIP7 and UBE2C were both involved in DNA replication. NIP7 or UBE2C silencing could significantly downregulate the expression levels of DNA polymerase epsilon, catalytic subunit 2 and replication factor C4 in DNA replication pathway. CONCLUSIONS NIP7 promotes ATC tumor growth by upregulating UBE2C to mediate DNA replication.
Humans ; Ubiquitin-Conjugating Enzymes/genetics* ; Thyroid Neoplasms/genetics* ; Thyroid Carcinoma, Anaplastic/genetics* ; Animals ; Mice, Nude ; Mice ; Cell Line, Tumor ; Cell Proliferation ; Up-Regulation ; RNA, Small Interfering/genetics* ; Nuclear Proteins/metabolism* ; Gene Expression Regulation, Neoplastic

BACKGROUND: Ferroptosis-related genes play a crucial role in regulating intracellular iron homeostasis and lipid peroxidation, and they are involved in the regulation of tumor growth and drug resistance. The expression of ferroptosis-related genes in tumor tissues can be used to predict patients' future survival times, aiding doctors and patients in anticipating disease progression. Based on the sequencing data of lung adenocarcinoma (LUAD) patients from The Cancer Genome Atlas (TCGA) database, this study identified genes involved in the regulation of ferroptosis, constructed a prognostic model, and evaluated the predictive performance of the model. METHODS: A total of 1467 ferroptosis-related genes were obtained from the GeneCards database. Gene expression profiles and clinical data from 541 LUAD patients were collected from the TCGA database. The expression data of all ferroptosis-related genes were extracted, and differentially expressed genes were identified using R software. Survival analysis was performed on these genes to screen for those with prognostic value. Subsequently, a prognostic risk scoring model for ferroptosis-related genes was constructed using LASSO regression model. Each LUAD patient sample was scored, and the patients were divided into high-risk and low-risk groups based on the median score. Receiver operating characteristic (ROC) curves were plotted, and the area under the curve (AUC) was calculated. Kaplan-Meier survival curves were generated to assess model performance, followed by validation in an external dataset. Finally, univariate and multivariate Cox regression analyses were conducted to evaluate the independent prognostic value and clinical relevance of the model. RESULTS: Through survival analysis, 121 ferroptosis-related genes associated with prognosis were initially identified. Based on this, a LUAD prognostic risk scoring model was constructed using 12 ferroptosis-related genes (ALG3, C1QTNF6, CCT6A, GLS2, KRT6A, LDHA, NUPR1, OGFRP1, PCSK9, TRIM6, IGF2BP1 and MIR31HG). The results indicated that patients in the high-risk group had significantly shorter survival time than those in the low-risk group (P<0.001), and the model demonstrated good predictive performance in both the training set (1-yr AUC=0.721) and the external validation set (1-yr AUC=0.768). Risk scores were significantly associated with the prognosis of LUAD patients in both univariate and multivariate Cox regression analyses (P<0.001), suggesting that this score is an important prognostic factor for LUAD patients. CONCLUSIONS This study successfully established a LUAD risk scoring model composed of 12 ferroptosis-related genes. In the future, this model is expected to be used in conjunction with the tumor-node-metastasis (TNM) staging system for prognostic predictions in LUAD patients.
Humans ; Ferroptosis/genetics* ; Prognosis ; Adenocarcinoma of Lung/pathology* ; Lung Neoplasms/pathology* ; Male ; Female ; Gene Expression Regulation, Neoplastic ; Middle Aged ; ROC Curve

BACKGROUND: Abnormalities of the switch/sucrose nonfermentable (SWI/SNF) chromatin-remodeling complex are closely related to various cancers, and ARID1B (AT-rich interaction domain 1B) is one of the core subunits of the SWI/SNF complex. Mutations or copy number deletions of the ARID1B gene are associated with impaired DNA damage response and altered chromatin accessibility. However, whether ARID1B deficiency affects the proliferation, migration and invasion abilities of non-small cell lung cancer (NSCLC) cells and its molecular mechanisms remain poorly understood. This study aims to reveal the regulatory role of ARID1B gene deletion on the malignant phenotype of NSCLC cells and its molecular mechanism. METHODS: Online databases were used to analyze the relationship between ARID1B and the prognosis of patients with lung cancer, and the expression levels of ARID1B in lung cancer tissues. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat) technology was employed to construct stable ARID1B gene knockout (KO) cell lines. The plate colony formation assay was used to detect cell proliferation, and the Transwell cell migration and invasion assays were used to detect changes in cell migration ability. RNA-Seq was utilized for the expression and enrichment analysis of differentially expressed genes. Western blot (WB) was used to verify the knockout effect of the ARID1B gene and to detect the expression changes of epithelial-mesenchymal transition (EMT) markers and mitogen-activated protein kinases (MAPK) signaling pathway-related proteins. Nude mouse tumor models were constructed and the tumorigenic abilities of control and ARID1B-deficient cells were compared. RESULTS: Patients with low ARID1B expression have poor overall survival. ARID1B is differentially expressed in lung cancer and normal tissues, and its expression level being lower in cancer cells. ARID1B-deficient cells had significantly enhanced in vitro proliferation, migration and invasion abilities. In animal experiments, the tumor formation speed of ARID1B gene deficient cells was significantly accelerated. Enrichment analysis of RNA-Seq results revealed that the differentially expressed genes were mainly enriched in MAPK, phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) and other signaling pathways. WB experiments demonstrated that the expressions of E-cadherin, N-cadherin and Vimentin changed in ARID1B gene deficient cells, and the expressions of MAPK and p-MAPK was increased. CONCLUSIONS The A549-ARID1B KO and PC9-ARID1B KO cell lines were successfully established. The ARID1B-deficient cell lines demonstrated high migration, invasion and proliferation potential at both in vitro and in vivo biological behavior levels and at the transcriptome sequencing level. The changes in the expression of EMT markers and the activation of the MAPK signaling pathway suggest possible metastasis mechanisms of ARID1B-deficient NSCLC.
Humans ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Lung Neoplasms/metabolism* ; Animals ; Carcinoma, Non-Small-Cell Lung/physiopathology* ; Transcription Factors/metabolism* ; Neoplasm Invasiveness ; Mice ; DNA-Binding Proteins/metabolism* ; Gene Deletion ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Mice, Nude ; Gene Expression Regulation, Neoplastic