miR-24-3p/KLF8 Signaling Axis Contributes to LUAD Metastasis by Regulating EMT

Role of microRNAs in host defense against porcine reproductive and respiratory syndrome virus infection: a hidden front line

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most globally devastating viruses threatening the swine industry worldwide. Substantial advancements have been achieved in recent years towards comprehending the pathogenesis of PRRSV infection and the host response, involving both innate and adaptive immune responses. Not only a multitude of host proteins actively participate in intricate interactions with viral proteins, but microRNAs (miRNAs) also play a pivotal role in the host response to PRRSV infection. If a PRRSV-host interaction at the protein level is conceptualized as the front line of the battle between pathogens and host cells, then their fight at the RNA level resembles the hidden front line. miRNAs are endogenous small non-coding RNAs of approximately 20-25 nucleotides (nt) that primarily regulate the degradation or translation inhibition of target genes by binding to the 3'-untranslated regions (UTRs). Insights into the roles played by viral proteins and miRNAs in the host response can enhance our comprehensive understanding of the pathogenesis of PRRSV infection. The intricate interplay between viral proteins and cellular targets during PRRSV infection has been extensively explored. This review predominantly centers on the contemporary understanding of the host response to PRRSV infection at the RNA level, in particular, focusing on the twenty-six miRNAs that affect viral replication and the innate immune response.

Upregulation of M6A Reader HNRNPA2B1 Associated with Poor Prognosis and Tumor Progression in Lung Adenocarcinoma

BACKGROUND

Lung cancer is the most prevalent malignancy worldwide, and lung adenocarcinoma (LUAD) accounts for a substantial proportion of all cases. N6-methyladenosine (m6A) is the most frequent post-transcriptional modification in mRNAs that also plays a role in cancer development. Heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) is a reader of m6A modification, which can affect tumor invasion, migration, and proliferation.

OBJECTIVES

The purpose of this study was to explore the prognostic factors of LUAD based on m6A through bioinformatics analysis.

MATERIALS AND METHODS

The expression levels and prognostic significance of HNRNPA2B1 in LUAD were analyzed on the basis of data extracted from the UALCAN, GEPIA, NCBI-GEO, Human Protein Atlas, STRING, miRDB, TargetScan, PROMO, Starbase, UCSC Xena browser, TIMER, and TISIDB databases. HNRNPA2B1 protein and mRNA levels in several LUAD cell lines were detected by western blotting and qRT-PCR. CCK8, wound-healing and transwell assays were performed to evaluate the proliferation, invasion, and migration abilities of LUAD cells.

RESULTS

HNRNPA2B1 mRNA was found to be significantly overexpressed in LUAD tissues, and its high levels correlated with poor OS and DFS. The genes co-expressed with HNRNPA2B1 were related to mRNA production, cell cycle, and histone binding. To determine the mechanistic basis of HNRNPA2B1 in LUAD, we next predicted the microRNAs and transcription factors that were directly associated with HNRNPA2B1, as well as copy number changes. In addition, it was found that HNRNPA2B1 expression was significantly related to CD4+ T cells, neutrophils, lymphocytes, immunomodulators, and chemokines. Besides, knocking down HNRNPA2B1 in the LUAD cells led to a significant reduction in their proliferation, invasion, and migration rates in vitro.

CONCLUSION

Elevated HNRNPA2B1 is a risk factor in LUAD and portends a poor prognosis.

GABARAPL1 is essential in extracellular vesicle cargo loading and metastasis development

BACKGROUND AND PURPOSE

Hypoxia is a common feature of tumours, associated with poor prognosis due to increased resistance to radio- and chemotherapy and enhanced metastasis development. Previously we demonstrated that GABARAPL1 is required for the secretion of extracellular vesicles (EV) with pro-angiogenic properties during hypoxia. Here, we explored the role of GABARAPL1+ EV in the metastatic cascade.

MATERIALS AND METHODS

GABARAPL1 deficient or control MDA-MB-231 cells were injected in murine mammary fat pads. Lungs were dissected and analysed for human cytokeratin 18. EV from control and GABARAPL1 deficient cells exposed to normoxia (21% O2) or hypoxia (O2 < 0.02%) were isolated and analysed by immunoblot, nanoparticle tracking analysis, high resolution flow cytometry, mass spectrometry and next-generation sequencing. Cellular migration and invasion were analysed using scratch assays and transwell-invasion assays, respectively.

RESULTS

The number of pulmonary metastases derived from GABARAPL1 deficient tumours decreased by 84%. GABARAPL1 deficient cells migrate slower but display a comparable invasive capacity. Both normoxic and hypoxic EV contain proteins and miRNAs associated with metastasis development and, in line, increase cancer cell invasiveness. Although GABARAPL1 deficiency alters EV content, it does not alter the EV-induced increase in cancer cell invasiveness.

CONCLUSION

GABARAPL1 is essential for metastasis development. This is unrelated to changes in migration and invasion and suggests that GABARAPL1 or GABARAPL1+ EV are essential in other processes related to the metastatic cascade.

MiRNA-30a-5p/VCAN Arrests Tumor Metastasis via Modulating the Adhesion of Lung Adenocarcinoma Cells

Previous research indicated that the dysregulation of miRNA-30a-5p has a correlation with cell metastasis of lung adenocarcinoma (LUAD). But the study about the molecular regulatory mechanism of miRNA-30a-5p in LUAD cell metastasis is limited. Thus, we discussed the mechanism of miRNA-30a-5p and its biological function in LUAD cells. By utilizing bioinformatics analysis, how miRNA-30a-5p was expressed in LUAD tissue was determined and its downstream target genes were predicted. The signaling pathways where these target genes enriched were analyzed. Several in vitro experiments were applied for cell function detection: dual-luciferase assay for validating the targeting relationship between miRNA-30a-5p and its target gene; quantitative real-time polymerase chain reaction for testing the expression of miRNA-30a-5p and its target gene in LUAD cells; MTT, transwell, cell adhesion, flow cytometry and immunofluorescence assays for examining the capabilities of LUAD cells to proliferate, migrate, invade, adhere, apoptosis and epithelial-mesenchymal transition (EMT) effect; Western blot for determining the expression of adhesion-related proteins and EMT-related proteins. Down-regulated miRNA-30a-5p was discovered in LUAD cells, but on the contrary, VCAN was upregulated. MiRNA-30a-5p overexpression notably repressed the virulent progression of LUAD cells. Besides, dual-luciferase assay validated the targeting relationship between miRNA-30a-5p and VCAN. MiRNA-30a-5p, by negatively regulating VCAN, was capable of hindering LUAD cell proliferation, migration, invasion, adhesion, viability and EMT. It was illustrated that miRNA-30a-5p could downregulate VCAN to retard the malignant progression of LUAD cells, which provides novel insights into LUAD pathogenesis, suggesting that miRNA-30a-5p/VCAN axis can be a promising anti-cancer target for LUAD.

Effect of circ_0000009 on lung adenocarcinoma progression by regulating PDZD2 in a ceRNA- and RBP- dependent manner

Accumulating evidence now demonstrated that circular RNAs (circRNAs) are closely related to the pathogenesis of lung adenocarcinoma (LUAD). Through GEO2R online analysis, we screened hsa_circ_0000009 (circ_0000009) from the GEO database (GSE158695), and its expression in LUAD cancer tissues and cell lines was detected by RT-qPCR. The looping structure of circ_0000009 was tested by RNase R and actinomycin D experiments. The changes of proliferation were tested by CCK-8 or EdU assay. And the changes of apoptosis in A549 and H1299 cells were measured via flow cytometry. The A549 BALB/c tumor model was established to evaluate the influence of circ_0000009 on LUAD cell growth in vivo. In addition, experiments connected with ceRNA direction (mainly including bioinformatics prediction and luciferase reporter assay) and RNA Binding Protein (RBP) direction (mainly including RNA pull-down assay, RIP assay and mRNA stability assay) were further developed to reveal the regulatory mechanism of circ_0000009. The gene and protein levels in this project were assessed by RT-qPCR and western blotting analysis, respectively. The data manifested that circ_0000009 was in low expression in LUAD. The in vitro and in vivo experiments threw light on that overexpression of circ_0000009 dramatically suppressing LUAD tumorigenesis. Mechanistically, circ_0000009 promoted the expression of PDZD2 by sponging miR-154-3p. Furthermore, circ_0000009 stabilized PDZD2 by recruiting IGF2BP2. This study illustrated the mechanism that overexpressing of circ_0000009 suppressed LUAD progression by upregulating PDZD2 expression, providing an original treatment direction for LUAD.

miR-6742-5p regulates the invasion and migration of lung adenocarcinoma cells via mediating FGF8/ERK12/MMP9/MMP2 signaling pathway

BACKGROUND

microRNAs (miRNAs) are involved in the progression of Lung adenocarcinoma (LUAD), however, the functions of miR-6742-5p in LUAD remains unknown, thereby this study was carried on.

METHODS

The mRNA and miRNA expression data from the LUAD and normal control were obtained from Gene Expression Omnibus (GEO) database, TargetScan and mirDIP were applied to predict the relationship between miR-6742-5p and FGF8.Q-PCR, western blot, dual-luciferase, wound Healing and transwell assays were performed to test the functions of miR-6742-5p in LUAD.

RESULTS

Bioinformatics analysis and dual-luciferase identified FGF8 is the target-gene of miR-6742-5p, which is declined in LUAD of human tissues and cell lines, and miR-6742-5P OE suppressed the progression of LUAD in nude mice. MiR-6742-5p OE and KD suppressed or increased the abilities of LUAD' metastasis tested by wound healing and transwell assays H522 and PC-9 cells, these effects about miR-6742-5p OE were reversed by FGF8; miR-6742-5p OE, KD inhibited and increased the expression of FGF8 as its downstream p-ERK1/2, MMP-2/-9, these results were corrected by ERK1/2 inhibitor: Ro 67-7476; the miR-6742-5p KD increased the migrated and invaded cells and suppressed by MMPs inhibitor: S3304. These results identified the negative correlation of miR-6742-5p with FGF8-ERK1/2 signal pathway in LUAD progression.

CONCLUSIONS

We conclude that miR-6742-5p might be a regulator of LUAD progression by targeting FGF8/ERK1/2/MMPs signaling pathway, which provides a novel therapeutic target for LUAD.

miR-24-3p Regulates Epithelial–Mesenchymal Transition and the Malignant Phenotype of Pancreatic Adenocarcinoma by Regulating ASF1B Expression

Anti-silencing function protein 1 homolog B (ASF1B) has been implicated in the occurrence and development of cancers. The present work explored the functional role and the expression regulation of ASF1B in pancreatic ductal adenocarcinoma (PDAC). Based on the real-time quantitative PCR (qRT-PCR) and immunohistochemistry (IHC), ASF1B was significantly upregulated in PDAC tissues. High expression of ASF1B was associated with a poor overall survival (OS) and recurrence-free survival (DFS) in the PDAC patients. ASF1B also showed a relatively higher expression in PDAC cells (AsPC-1, PANC-1) when compared with human pancreatic ductal epithelial cells (HPDFe-6). CCK8 and clone formation assay demonstrated that silencing ASF1B impaired the proliferation in PANC-1 and AsPC-1 cells, and Annexin V-PI staining showed an increased level of apoptosis upon ASF1B silencing. ASF1B silencing also suppressed the migration and invasion in PDAC cells, as revealed by Transwell assays. We further showed that miR-24-3p was downregulated in PDAC tissues and cells, which functionally interacted with ASF1B by dual-luciferase reporter assay. miR-24-3p negatively regulated ASF1B expression to modulate the malignant phenotype of PDAC cells. ASF1B shows high expression in PDAC, which promotes the malignancy and EMT process of PDAC cells. miR-24-3p is a negative regulator of ASF1B and is downregulated in PDAC cells. Our data suggest that targeting ASF1B/miR-24-3p axis may serve as an intervention strategy for the management of PDAC.

HEG1 as a novel potential biomarker for the prognosis of lung adenocarcinoma

BACKGROUND

Heart development protein with EGF-like domains 1 (HEG1), generally related to angiogenesis and embryonic development, was reported to participate in the occurrence and progression of some tumors recently. However, the role of HEG1 in lung adenocarcinoma (LUAD) is unclear.

PATIENTS AND METHODS

To explore the effect of HEG1 on LUAD, GEPIA platform and UALCAN database, as well as Kaplan-Meier plotter were adopted to analyze the association of HEG1 with clinicopathological characteristics and survival outcomes for LUAD firstly. And then the HEG1 in LUAD tissues, blood and cell lines were detected by qRT-PCR, western blot, immunofluorescence, immunohistochemistry, and ELISA. Gene set enrichment analysis (GSEA) was conducted to identify pathways that might be affected by HEG1 in LUAD.

RESULTS

In this study, HEG1 in lung tissues and cell lines of LUAD were significantly downregulated compared to benign pulmonary disease tissues and alveolar epithelial cells (p < 0.05). Moreover, compared with other groups, patients with advanced tumor stage had lower HEG1 mRNA expression levels (p = 0.025), which were negatively correlated with Ki67 index in tumor tissues (r = -0.427, p = 0.033). On the other hand, the LUAD patients with lower HEG1 had shorter overall survival (OS) (HR = 0.51, 95% CI: 0.40-0.65, p < 0.001) according to Kaplan-Meier plotter. In addition, HEG1 in serum of LUAD patients was negatively associated with CEA (r = -0.636, p < 0.001). GSEA showed that HEG1 was enriched in various metabolic-related pathways, including glucose metabolism, lipid metabolism, and nucleotide metabolism signaling.

CONCLUSIONS

HEG1 was downregulated in LUAD patients and associated with poor prognosis, which indicating HEG1 may serve as a potential biomarker for diagnosis and prognosis of LUAD.

MiR-30a-3p Suppresses the Growth and Development of Lung Adenocarcinoma Cells Through Modulating GOLM1/JAK-STAT Signaling

A considerable amount of people succumbs to lung adenocarcinoma (LUAD) due to its high incidence and mortality. This study attempted to reveal the impacts of GOLM1 on LUAD. This work analyzed GOLM1 expression in LUAD and normal tissue and studied its prognostic value utilizing data from The Cancer Genome Atlas. RNA and protein levels were, respectively, determined utilizing qRT-PCR and western blot. Cell-aggressive behaviors were assessed employing Cell Counting Kit-8, scratch healing, and Transwell assays. The targetting relationship between GOLM1 and miR-30a-3p was assayed by dual-luciferase method. GOLM1 up-regulation in LUAD was found in TCGA and it was also a negative factor for survival in patients. GOLM1 overexpression promoted cell progression in LUAD. Down-regulated miR-30a-3p in LUAD was an upstream regulatory miRNA of GOLM1 in terms of molecular mechanism. Further, rescue assays illustrated that miR-30a-3p overexpression attenuated the GOLM1 facilitating impacts on LUAD progression. Finally, we proved that miR-30a-3p/GOLM1 regulated progression of LUAD cells via JAK-STAT pathway. Collectively, the inhibitory impacts of miR-30a-3p on LUAD growth may be mediated by GOLM1/JAK-STAT, which may contribute to the diagnosis of LUAD therapy and the development of therapeutic tools.

Hsa-miR-335 enhances cell migration and invasion in lung adenocarcinoma through targeting Copine-1

Lung adenocarcinoma (LAC) is one of the most common pulmonary adenocarcinomas with a high peak of mortality, and metastasis is the main culprit of LAC deaths. microRNAs play important role in cancer metastasis, and thus are regarded as potential diagnostic and prognostic markers for human cancers. However, many miRNAs exhibit dual roles in diverse cellular contexts. Here, we revealed that hsa-miR-335, a previously reported tumor suppressor, exhibited an oncogenic role in LAC. Overexpression of miR-335 enhanced the abilities of A549 and H1299 cells to invade and migrate by regulating epithelial-mesenchymal transition, while inhibition of miR-335 exhibited an opposite effect in vitro and in vivo. Mechanically, miR-335 inhibited the expression of Copine-1 (CPNE1), an NF-κB suppressor, through interacting with its mRNA 3'UTR, while mutating the binding sites abolished this inhibitory effect. This finding not only highlights the suppressive effect of CPNE1 on cell motility, but also provides new insight into miR-335 in promoting LAC metastasis.

The role of Krüppel-like factor 8 in cancer biology: Current research and its clinical relevance

Cancer is one of the leading causes of mortality worldwide, ranked second after heart disease. Despite recent advancements in diagnosis and treatment, there are still numerous problems associated with cancer progression, disease recurrence, and therapeutic resistance that are partially explored. Several studies have recently revealed that Krüppel-like factor 8 (KLF8) regulates transcription of genes linked with diverse biological processes, including proliferation, epithelial to mesenchymal transition (EMT), migration, invasion, and inflammation. KLF8 is expressed ubiquitously in mammalian cells, and its aberrant expression has been manifested with several cancer types. Earlier studies demonstrated the crucial role of KLF8 in DNA repair and resistance to apoptosis in numerous cancer types. Hence, studying the function of KLF8 from the perspective of cancer progression and therapy resistance would help develop a new therapeutic avenue. In this review, we summarize the clinical relevance of KLF8 expression in various malignancies, focusing on recent updates in EMT, cellular signaling, and cancer stem cells. We also address the contribution of KLF8 in development, DNA repair, chemoresistance, and its clinical utility as a predictive biomarker.

MicroRNA-24 in Cancer: A Double Side Medal With Opposite Properties

MicroRNA-24 (miR-24) has been widely studied in a variety of human cancers, which plays different roles in specific type of cancers. In the present review, we summarized the recent surveys regarding the role of miR-24 in different human cancers. On the one hand, miR-24 was reported to be down-regulated in some types of cancer, indicating its role as a tumor suppressor. On the other hand, it has shown that miR-24 was up-regulated in some other types of cancer, even in the same type of cancer, suggesting the role of miR-24 being as an oncogene. Firstly, miR-24 was dysregualted in human cancers, which is related to the clinical performance of cancer patients. Thus miR-24 could be used as a potential non-invasive diagnostic marker in human cancers. Secondly, miR-24 was associated with the tumor initiation and progression, being as a promoter or inhibitor. Therefore, miR-24 might be an effective prognostic biomarker in different type of cancers. Lastly, the abnormal expression of miR-24 was involved in the chemo- and radio- therapies of cancer patients, indicating the role of miR-24 being as a predictive biomarker to cancer treatment. Totally, miR-24 contributes to tumorigenesis, tumor progression, and tumor therapy, which closely related to clinic. The present review shows that miR-24 plays a double role in human cancers and provides plenty of evidences to apply miR-24 as a potential novel therapeutic target in treating human cancers.