Silencing of lncRNA DLEU1 inhibits tumorigenesis of ovarian cancer via regulating miR-429/TFAP2A axis

TFAP2A Activates S100A2 to Mediate Glutamine Metabolism and Promote Lung Adenocarcinoma Metastasis

BACKGROUND

Lung adenocarcinoma (LUAD) is a fatal disease with metabolic abnormalities. The dysregulation of S100 calcium-binding protein A2 (S100A2), a member of the S100 protein family, is connected to the development of various cancers. The impact of S100A2 on the LUAD occurrence and metastasis, however, has not yet been reported. The functional mechanism of S100A2 on LUAD cell metastasis was examined in this article.

METHODS

The expression of TFAP2A and S100A2 in LUAD tissues and cells was analyzed by bioinformatics and qRT-PCR, respectively. The enrichment pathway analysis was performed on S100A2. Bioinformatics analysis determined the binding relationship between TFAP2A and S100A2, and their interaction was validated through dual-luciferase and chromatin immunoprecipitation experiments. Cell viability was determined using cell counting kit-8 (CCK-8). A transwell assay was performed to analyze the invasion and migration of cells. Immunofluorescence was conducted to obtain vimentin and E-cadherin expression, and a western blot was used to detect the expression of MMP-2, MMP-9, GLS, and GLUD1. The kits measured the NADPH/NADP ratio, glutathione (GSH)/glutathione disulfide (GSSG) levels, and the contents of glutamine, α-KG, and glutamate.

RESULTS

S100A2 was upregulated in LUAD tissues and cells, and S100A2 mediated glutamine metabolism to induce LUAD metastasis. Additionally, the transcriptional regulator TFAP2A was discovered upstream of S100A2, and TFAP2A expression was upregulated in LUAD, which indicated that TFAP2A promoted the S100A2 expression. The rescue experiment found that upregulation of S100A2 could reverse the inhibitory effects of silencing TFAP2A on glutamine metabolism and cell metastasis.

CONCLUSION

In conclusion, by regulating glutamine metabolism, the TFAP2A/S100A2 axis facilitated LUAD metastasis. This suggested that targeting S100A2 could be beneficial for LUAD treatment.

Circ_0003789 Knockdown Inhibits Tumor Progression by miR-429/ZFP36L2 Axis in Gastric Cancer

An increasing number of circRNAs have been found to be involved in the development of gastric cancer. However, the function of circ_0003789 in regulating gastric cancer progression is unclear. Here, we aimed to investigate the expression, function and molecular mechanism of circ_0003789 in gastric cancer pathogenesis. Circ_0003789, miR-429 and ZFP36 ring finger protein like 2 (ZFP36L2) mRNA were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was illustrated by 5-Ethynyl-2'-deoxyuridine (Edu), cell counting kit-8 (CCK-8) and colony formation assays. Apoptosis was determined by flow cytometry. Protein level was detected by Western blotting assay. Xenograft assays were used for functional analysis of circ_0003789 in vivo. The relationship between miR-429 and circ_0003789 or ZFP36L2 was predicted by starbase3.0 online database and identified by dual luciferase reporter assay. The expression levels of circ_0003789 and ZFP36L2 were significantly upregulated in gastric cancer tissues and cells, while the expression of miR-429 was downregulated. Downregulation of circ_0003789 inhibited gastric cancer cell growth and invasion and promoted apoptosis in vitro. Circ_0003789 acted as a sponge of miR-429. Moreover, miR-429 silencing by miR-429 inhibitors attenuated the effects of circ_0003789 interference on cell growth, apoptosis and invasion. ZFP36L2 was targeted by miR-429, and the effects of miR-429 on cell growth, invasion and apoptosis were attenuated by ZFP36L2 overexpression. Circ_0003789 could enhance ZFP36L2 expression by interacting with miR-429. Silencing of circ_0003789 inhibited tumor growth in vivo. Circ_0003789 regulates tumor progression in gastric cancer through miR-429/ZFP36L2 axis. This finding implies that circ_0003789 may be a therapeutic target for gastric cancer.

Potential prognosis and immunotherapy predictor TFAP2A in pan-cancer

BACKGROUND

TFAP2A is critical in regulating the expression of various genes, affecting various biological processes and driving tumorigenesis and tumor development. However, the significance of TFAP2A in carcinogenesis processes remains obscure.

METHODS

In our study, we explored multiple databases including TCGA, GTEx, HPA, cBioPortal, TCIA, and other well-established databases for further analysis to expound TFAP2A expression, genetic alternations, and their relationship with the prognosis and cellular signaling network alternations. GO term and KEGG pathway enrichment analysis as well as GSEA were conducted to examine the common functions of TFAP2A. RT-qPCR, Western Blot and Dual Luciferase Reporter assay were employed to perform experimental validation.

RESULTS

TFAP2A mRNA expression level was upregulated and its genetic alternations were frequently present in most cancer types. The enrichment analysis results prompted us to investigate the changes in the tumor immune microenvironment further. We discovered that the expression of TFAP2A was significantly associated with the expression of immune checkpoint genes, immune subtypes, ESTIMATE scores, tumor-infiltrating immune cells, and the possible role of TFAP2A in predicting immunotherapy efficacy. In addition, high TFAP2A expression significantly correlated with several ICP genes, and promoted the expression of PD-L1 on mRNA and protein levels through regulating its expression at the transcriptional level. TFAP2A protein level was upregulated in fresh colon tumor tissue samples compared to that in the adjacent normal tissues, which essentially positively correlated with the expression of PD-L1.

CONCLUSIONS

Our study suggests that targeting TFAP2A may provide a novel and effective strategy for cancer treatment.

NGS-based profiling identifies miRNAs and pathways dysregulated in cisplatin-resistant esophageal cancer cells

Esophageal cancer (EC) incidence remains to be on a global rise supported by an unchanged recurrence and 5-year survival rate owing to the development of chemoresistance. Resistance to cisplatin, one of the majorly used chemotherapeutic drugs in EC, is a major nuisance. This study sheds light on miRNA dysregulation and its inverse relation with dysregulated mRNAs to guide pathways into the manifestation of cisplatin resistance in EC. A cisplatin-resistant version of an EC cell line was established and comparative profiling by NGS with the parental cell line was employed to identify dysregulation in miRNA and mRNA levels. Protein-protein interaction network analysis was done using Cytoscape, followed by Funrich pathway analysis. Furthermore, selective significant miRNAs were validated using qRT-PCR. miRNA-mRNA integrated analysis was carried out using the Ingenuity Pathway Analysis (IPA) tool. Expression of various established resistance markers supported the successful establishment of cisplatin-resistant cell line. Whole-cell small RNA sequencing and transcriptome sequencing identified 261 miRNAs and 1892 genes to be significantly differentially expressed (DE), respectively. Pathway analysis indicated enrichment of EMT signaling, supported by NOTCH, mTOR, TNF receptor, and PI3K-mediated AKT signaling pathways, in chemoresistant cells. Validation by qRT-PCR confirmed upregulation of miR-10a-5p, miR-618, miR-99a-5p, and miR-935 and downregulation of miR-335-3p, miR-205-5p, miR-944, miR-130a-3p, and miR-429 in resistant cells. Pathway analysis that followed IPA analysis indicated that the dysregulation of these miRNAs and their target genes may be instrumental in the development and regulation of chemoresistance via p53 signaling, xenobiotic metabolism, and NRF2-mediated oxidative stress. This study concludes the interplay between miRNA and mRNA as an important aspect and occurrence in guiding the regulation, acquisition, and maintenance of chemoresistance in esophageal cancer in vitro.

Landscape and Construction of a Novel N6-methyladenosine-related LncRNAs in Cervical Cancer

Cervical cancer is a crucial clinical problem with high mortality. Despite much research in therapy, the prognosis of patients with cervical cancer is still not ideal. The data on cervical cancer were downloaded from The Cancer Genome Atlas (TCGA) portal. R language was used to screen out the N6-methyladenosine (m6A)-related lncRNAs (long non-coding RNA). A consensus clustering algorithm was performed to identify m6A-related lncRNAs in cervical cancer; 10 m6A-related lncRNAs showing a significant association with survival were filtrated through a gradually univariate Cox regression model, least absolute shrinkage and selection operator (LASSO) algorithm, and multivariate Cox regression preliminarily. Furthermore, we conducted Kaplan-Meier curves, receiver operating curve (ROC) analyses, and proportional hazards model to quantify the underlying character of the m6A-related model in the prevision of cervical cancer patients. Gene set enrichment analysis (GSEA) was used to explore several pathways significantly. Finally, cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) was applied to estimate the immune cell infiltration in the profiling. In the present study, 10 m6A-related lncRNAs make up our prediction model. This prediction model can do duty for an independent predictive biomolecular element. Subsequently, we then found that the model was still valid in further validation of the training group and the test group. Our signature was correlated with immune cell infiltration and partial signaling pathway. These lncRNAs played a no negligible biomolecular role in contributing to the prognosis of cervical cancer.

The oncogenic role of TFAP2A in bladder urothelial carcinoma via a novel long noncoding RNA TPRG1-AS1/DNMT3A/CRTAC1 axis

BACKGROUND

Overexpression of TFAP2A has been linked to increased lymph node metastasis in basal-squamous bladder cancer. However, its downstream targets in bladder urothelial carcinoma (BLCA), the most malignant cancer of the urinary tract, remain unclear. In the current study, we aim to explore the function and mechanism of TFAP2A in BLCA.

METHODS

TFAP2A expression and the prognostic significance in BLCA was analyzed using TCGA and GTEX projects. TFAP2A was knocked-down in BLCA cells to study its impact on glucose uptake, lactate and ATP production, expression of HK2, and the number of vascular meshes formed by HUVEC. The target long noncoding RNAs (lncRNAs) of TFAP2A were predicted by bioinformatics tools, followed by ChIP-qPCR and luciferase assays. The downstream targets of TPRG1-AS1 were analyzed by microarray analysis. Rescue experiments were conducted for validation.

RESULTS

TFAP2A upregulation in BLCA predicted dismal survival of patients. Loss of TFAP2A inhibited glycolysis (as evidenced by reduced glucose uptake, lactate, ATP production, and the expression of HK2) and angiogenesis (decreased number of vascular meshes formed by HUVEC). TFAP2A promoted the transcription of TPRG1-AS1. TPRG1-AS1 reversed the inhibitory effect of TFAP2A knockdown on glycolysis and angiogenesis in BLCA cells. TPRG1-AS1 inhibited the transcription of CRTAC1 by recruiting a DNA methyltransferase to the promoter of CRTAC1 and increasing the DNA methylation of its promoter. CRTAC1 inhibited glycolysis and angiogenesis in BLCA cells. TFAP2A silencing curbed tumor growth in vivo via the TPRG1-AS1/CRTAC1 axis.

CONCLUSION

TFAP2A reduces CRTAC1 expression by promoting TPRG1-AS1 transcription, thereby expediting BLCA glycolysis and angiogenesis.

The expression level of chicken telomerase reverse transcriptase in tumors induced by ALV-J is positively correlated with methylation and mutation of its promoter region

Avian leukosis virus subgroup J (ALV-J) can cause neoplastic diseases in poultry and is still widely prevalent in China. Chicken telomerase reverse transcriptase (chTERT) is the core component of telomerase, which is closely related to the occurrence and development of tumors. Our previous studies showed that chTERT is overexpressed in ALV-J tumors, but the mechanism is still not completely clear. Therefore, this study aims to analyze the possible molecular mechanism of chTERT overexpression in ALV-J tumors from the perspective of DNA methylation and promoter mutation. Methylation sequencing of the chTERT amplicon showed that ALV-J replication promoted the methylation level of the chTERT promoter. And the methylation level of the chTERT promoter in ALV-J tumors was significantly higher than that in tumor-adjacent and normal tissues. Compared with the tumor-adjacent and normal tissues, the chTERT promoter in each ALV-J tumors tested had a mutation of -183 bp C > T, and 36.0% (9/25) of the tumors also had mutations of -184 bp T > C, -73 bp::GGCCC and -56 bp A > T in the chTERT promoter, which formed the binding sites for the transcription factors NFAT5, TFAP2A and ZEB1, respectively. The results of RT-qPCR and Western blotting showed that the occurrence of these mutations significantly increased the expression level of chTERT. In conclusion, this study demonstrated that the high expression of chTERT in ALV-J tumors is positively correlated with the level of hypermethylation and mutation in its promoter, which provides a new perspective for further research on the molecular mechanism of chTERT in ALV-J tumorigenesis.

Metastatic EMT Phenotype Is Governed by MicroRNA-200-Mediated Competing Endogenous RNA Networks

Epithelial–mesenchymal transition (EMT) is a fundamental physiologically relevant process that occurs during morphogenesis and organ development. In a pathological setting, the transition from epithelial toward mesenchymal cell phenotype is hijacked by cancer cells, allowing uncontrolled metastatic dissemination. The competing endogenous RNA (ceRNA) hypothesis proposes a competitive environment resembling a large-scale regulatory network of gene expression circuits where alterations in the expression of both protein-coding and non-coding genes can make relevant contributions to EMT progression in cancer. The complex regulatory diversity is exerted through an array of diverse epigenetic factors, reaching beyond the transcriptional control that was previously thought to single-handedly govern metastatic dissemination. The present review aims to unravel the competitive relationships between naturally occurring ceRNA transcripts for the shared pool of the miRNA-200 family, which play a pivotal role in EMT related to cancer dissemination. Upon acquiring more knowledge and clinical evidence on non-genetic factors affecting neoplasia, modulation of the expression levels of diverse ceRNAs may allow for the development of novel prognostic/diagnostic markers and reveal potential targets for the disruption of cancer-related EMT.

LncRNA DLEU1 is overexpressed in premature ovarian failure and sponges miR-146b-5p to increase granulosa cell apoptosis

Background

miR-146b-5p has been reported to participate in premature ovarian failure (POF) in mice. However, its role in POF patients is unclear. We predicted that miR-146b-5p might interact with lncRNA DLEU1, a crucial player in ovarian cancer. We then explored the interaction between DLEU1 and miR-146b-5p.

Methods

Expression of DLEU1 and miR-146b-5p in POF and control ovary tissues was determined by RT-qPCR. The subcellular location of DLEU1 in human KGN cells was analyzed using subcellular fractionation assays. The direct interaction between DLEU1 and miR-146b-5p was analyzed using RNA pull-down assays. The role of DLEU1 in miR-146a expression was analyzed using overexpression assay. Cell proliferation was analyzed using cell apoptosis assay.

Results

Increased DLEU1 expression and decreased miR-146b-5p expression were observed in POF. DLEU1 directly interacted with MiR-146b-5p and was expressed in both nuclear and cytoplasm samples of KGN cells. In KGN cells, DLEU1 and miR-146b-5p failed to regulate the expression of each other. However, DLEU1 promoted cell apoptosis and reduced the inhibitory effects of miR-146b-5p on cell apoptosis.

Conclusions

DLEU1 is overexpressed in POF and sponges miR-146b-5p to increase KGN cell apoptosis.

Interference of long non-coding RNA HAGLROS inhibits the proliferation and promotes the apoptosis of ovarian cancer cells by targeting miR-26b-5p

Ovarian cancer (OV) is the fifth most common type of cancer affecting women worldwide. Long non-coding RNAs (lncRNAs) serve essential roles in the progression of OV. As such, the present study aimed to investigate the specific role of HAGLR opposite strand lncRNA (HAGLROS) in OV and the underlying mechanism of action through which HAGLROS exerts its effects on OV cells. In the present study, the expression of HAGLROS in several OV cell lines was first detected using reverse transcription-quantitative PCR. HAGLROS was then silenced to evaluate cell viability, proliferation and apoptosis, which were determined using Cell Counting Kit-8, colony formation and TUNEL assays, respectively. Additionally, immunofluorescence staining and western blotting were used to confirm the expression profile of proliferation- and apoptosis-related proteins. Moreover, a dual luciferase reporter assay was used to verify the potential interactions between HAGLROS and microRNA (miR)-26b-5p. Subsequently, rescue assays were performed to investigate the effects of HAGLROS and miR-26b-5p on OV progression. The results indicated that HAGLROS was highly expressed in OV cells. Interference of HAGLROS led to a decrease in the proliferation, but an increase in the apoptosis of OV cells, accompanied by downregulated expression levels of Ki67 and Bcl-2, and upregulated expression levels of Bax and cleaved caspase-3. Further study revealed that HAGLROS acted as a sponge for miR-26b-5p and positively regulated its expression. miR-26b-5p inhibitor transfection partially reversed the effects of HAGLROS knockdown on the proliferation and apoptosis of OV cells. In conclusion, the results of the present study suggested that interference of HAGLROS suppressed the proliferation and promoted the apoptosis of OV cells through regulating miR-26b-5p, indicating that HAGLROS may be a promising biomarker in OV diagnosis and treatment.