MiR-452-5p promotes colorectal cancer progression by regulating an ERK/MAPK positive feedback loop

The RNA binding protein IGF2BP2/IMP2 alters the cargo of cancer cell-derived extracellular vesicles supporting tumor-associated macrophages

BACKGROUND

Tumor cells release extracellular vesicles (EVs) that contribute to the polarization of macrophages towards tumor-associated macrophages (TAMs). High expression levels of the RNA binding protein IGF2BP2/IMP2 are correlated with increased tumor cell proliferation, invasion, and poor prognosis in the clinic. However, there is a lack of understanding of whether IMP2 affects the cargo of cancer cell-derived EVs, thereby modulating macrophage polarization.

METHODS

EVs were isolated from IMP2-expressing HCT116 parental cells (WT) and CRISPR/Cas9 IMP2 knockout (KO) cells. EVs were characterized according to MISEV guidelines, microRNA cargo was assessed by microRNA-Seq, and the protein cargo was analyzed by proteomics. Primary human monocyte-derived macrophages (HMDMs) were polarized by EVs, and the expression of genes and surface markers was assessed using qPCR and flow cytometry, respectively. Morphological changes of macrophages, as well as the migratory potential of cancer cells, were assessed by the Incucyte® system and macrophage matrix degradation potential by zymography. Changes in the metabolic activity of macrophages were quantified using a Seahorse® analyzer. For in vivo studies, EVs were injected into the yolk sac of zebrafish larvae, and macrophages were isolated by fluorescence-activated cell sorting.

RESULTS

EVs from WT and KO cells had a similar size and concentration and were positive for 25 vesicle markers. The expression of tumor-promoting genes was higher in macrophages polarized with WT EVs than KO EVs, while the expression of TNF and IL6 was reduced. A similar pattern was observed in macrophages from zebrafish larvae treated in vivo. WT EV-polarized macrophages showed a higher abundance of TAM-like surface markers, higher matrix degrading activity, as well as a higher promotion of cancer cell migration. MicroRNA-Seq revealed a significant difference in the microRNA composition of WT and KO EVs, particularly a high abundance of miR-181a-5p in WT EVs, which was absent in KO EVs. Inhibitors of macropinocytosis and phagocytosis antagonized the delivery of miR-181a-5p into macrophages and the downregulation of the miR-181a-5p target DUSP6. Proteomics data showed differences in protein cargo in KO vs. WT EVs, with the differentially abundant proteins mainly involved in metabolic pathways. WT EV-treated macrophages exhibited a higher basal oxygen consumption rate and a lower extracellular acidification rate than KO EV-treated cells.

CONCLUSION

Our results show that IMP2 determines the cargo of EVs released by cancer cells, thereby modulating the EVs' actions on macrophages. Expression of IMP2 is linked to the secretion of EVs that polarize macrophages towards a tumor-promoting phenotype.

Exploring the Key Signaling Pathways and ncRNAs in Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent cancer to be diagnosed, and it has a substantial mortality rate. Despite numerous studies being conducted on CRC, it remains a significant health concern. The disease-free survival rates notably decrease as CRC progresses, emphasizing the urgency for effective diagnostic and therapeutic approaches. CRC development is caused by environmental factors, which mostly lead to the disruption of signaling pathways. Among these pathways, the Wingless/Integrated (Wnt) signaling pathway, Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, Mitogen-Activated Protein Kinase (MAPK) signaling pathway, Transforming Growth Factor-β (TGF-β) signaling pathway, and p53 signaling pathway are considered to be important. These signaling pathways are also regulated by non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). They have emerged as crucial regulators of gene expression in CRC by changing their expression levels. The altered expression patterns of these ncRNAs have been implicated in CRC progression and development, suggesting their potential as diagnostic and therapeutic targets. This review provides an overview of the five key signaling pathways and regulation of ncRNAs involved in CRC pathogenesis that are studied to identify promising avenues for diagnosis and treatment strategies.

Differentially expressed miR-4310 functions as a tumor suppressor in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a digestive tract malignancy microRNAs (miRNAs) have attracted much attention as biomarkers in tumor studies.

OBJECTIVE

This work focused on the predictive potential and mechanism of miR-4310 in CRC.

METHODS

The miRNA expression profile sets were obtained from the Gene Expression Omnibus (GEO) database, and the appropriate miRNA was screened by GEO2R. The CRC tissues and control tissues of 88 patients with CRC were collected, and the expression of miR-4310 was detected by quantitative real-time PCR, and the efficacy of miR-4310 in diagnosing CRC was evaluated by the receiver operating characteristic curve (ROC). The effects of miR-4310 on the proliferation, migration, and invasion of CRC cells were explored by Cell Counting Kit-8 (CCK-8) and Transwell experiments. Predicting the potential binding sites of miR-4310 and Runt-related transcription factor 1 (RUNX1) by four predictive websites. The relationship between miR-4310 and RUNX1 was confirmed by a double luciferase reporter gene experiment.

RESULTS

The bioinformatics analysis found that miR-4310 was differentially expressed in CRC tissues and this finding was certified by the expression of miR-4310 in CRC tissues of collected patients and cultured CRC cell lines. The expression of miR-4310 had a predictive possibility for CRC patients. MiR-4310/RUNX1 pathway had effects on CRC viability, migration, and invasion.

CONCLUSION

MiR-4310 had the potential to be a biomarker for early screening of CRC. MiR-4310 and RUNX1 participated in the regulation of CRC cells.

MiR-452-5p facilitates retinoblastoma cell growth and invasion via the SOCS3/JAK2/STAT3 pathway

Retinoblastoma (RB) is an intraocular tumor in children. Accumulated evidence confirms that microRNAs (miRNAs) exert critical functions in RB. This research aimed to investigate the miR-452-5p function in RB. MiR-452-5p expressions in RB were tested with quantitative real-time polymerase chain reaction (PCR). MiR-452-5p functions in RB were evaluated via Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine assay, flow cytometry, Western blot, and Transwell. MiR-452-5p mechanism in RB was assessed using bioinformatics software Starbase and dual-luciferase reporter gene assay. Meanwhile, miR-452-5p function in RB in vivo was examined by constructing tumor xenografts in nude mice, immunohistochemistry, and Western blot assays. MiR-452-5p was overexpressed in RB tissues and cells, and miR-452-5p expression was positively correlated with RB clinicopathology including the Largest tumor base (mm) and Differentiation. Functionally, miR-452-5p knockdown restrained RB cell proliferation, invasion, epithelial-mesenchymal transition (EMT), and facilitated cell apoptosis. Mechanistically, suppressors of cytokine signaling (SOCS3) knockdown restored the inhibitory effects of miR-452-5p knockdown on RB cells. Meanwhile, in vivo studies further corroborated that miR-452-5p knockdown reduced RB tumor growth, EMT, and accelerated apoptosis in vivo. Also, miR-452-5p knockdown increased SOCS3 protein levels, and decreased phosphorylated Janus kinase 2/Janus kinase 2 (JAK2), phosphorylated signal transducer and activator of transcription 3/signal transducer and activator of transcription 3 (STAT3) in vivo. MiR-452-5p accelerated RB cell growth and invasion by SOCS3/JAK2/STAT3.

MicroRNA 452 regulates SHC1 expression in human colorectal cancer and colitis

BACKGROUND

Human microRNA 452 (MIR452) has been linked to both colorectal cancer (CRC) tissues and dextran sulfate sodium (DSS)-induced colitis.

OBJECTIVE

We analyzed the correlation between MIR452 and its putative target gene in human CRC cells and in mouse colitis tissues.

METHODS

Luciferase reporter assay confirmed that Src homologous and collagen adaptor protein 1 (SHC1) is a direct target of MIR452. Furthermore, the expression of proteins or mRNA was assessed by immunohistochemical analysis, Western blot, or quantitative RT-PCR (qRT-PCR).

RESULTS

We found that MIR452 has a potential binding site at 3'-UTR of SHC1. Likewise, MIR452 or siSHC1 transfection dramatically reduced the level of cellular SHC1 in CRC cells. The expression of SHC1 was frequently downregulated in both human CRC tissues and mouse colitis tissues. In CRC cells, we demonstrated that MIR452 regulated the expression of genes involved in the SHC1-mediated KRAS-MAPK signal transduction pathways.

CONCLUSION

These findings suggest a potential defense mechanism in which MIR452 regulation of the adaptor protein SHC1 maintains cellular homeostasis during carcinogenesis or chronic inflammation. Therefore, MIR452 may have therapeutic value for human early-stage CRC and colitis.

Role of Mir-452-5p Overexpression in Epithelial-Mesenchymal Transition (EMT) in Early-stage Colorectal Cancer

BACKGROUND/AIM

The microRNA miR-452-5p holds a critical role in the progression of multiple tumor formations, but there is limited understanding regarding the epithelial-mesenchymal transition (EMT) progression and its underlying mechanisms in the early-stage colorectal cancer (CRC). We aimed to explore the change in miRNA expression in early-stage CRC and examine the role of these miRNAs in CRC.

MATERIALS AND METHODS

The expression levels of miR-452-5p in tissues and cells of early-stage CRC were determined by real-time quantitative polymerase chain reaction. Additionally, the biological effects of miR-452-5p on CRC were investigated by in vitro functional experiments.

RESULTS

The expression levels of miR-452-5p were found increased in early-stage CRC tissue. We found that miR-452-5p promoted CRC cell proliferation but inhibited epithelial-mesenchymal transition. Furthermore, miR-452-5p promoted cell proliferation through activation of the extracellular signal-regulated kinase pathway, and inhibited cell invasion through suppression of Slug (Snail2) expression and up-regulation of E-cadherin expression.

CONCLUSION

The expression of miR-452-5p is up-regulated in early CRC and suppresses epithelial-mesenchymal transition in CRC. These discoveries suggest that miR-452-5p has the potential to serve as a viable therapeutic target for CRC.

A Novel Circ_Arf3/miR-452-5p/Mbnl1 Axis Regulates Proliferation and Expression of Fibrosis-Related Proteins of Mouse Mesangial Cells Under High Glucose

Background

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes that may lead to chronic renal failure and end-stage renal disease. Circular RNAs (circRNAs) play important roles in DN progression. However, the action of circRNA ADP ribosylation factor 3 (circ_Arf3) in high glucose (HG)-induced change is still unclear.

Methods

Mouse mesangial cells (MCs) were treated with 30 mM HG as a DN cell model in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine the expression levels of circ_Arf3, microRNA (miR)-452-5p and muscleblind like splicing regulator 1 (Mbnl1). The proliferation of HG-treated MCs was assessed using 5 Ethynyl 2' deoxyuridine (EdU) and cell counting kit-8 (CCK-8) assays, and the levels of proliferation and fibrosis-related proteins and Mbnl1 were detected by Western blot. Dual-luciferase reporter and RNA pull-down assays were utilized to determine the relationship between miR-452-5p and circ_Arf3 or Mbnl1.

Results

Our results discovered that circ_Arf3 and Mbnl1 were lowly expressed in HG-treated MCs, while miR-452-5p expression was up-regulated. Moreover, circ_Arf3 was mainly located in the cytoplasm and had a ring-like stable structure. Functional assays demonstrated that overexpression of circ_Arf3 prevented cell proliferation and fibrous formation in HG-treated MCs. Circ_Arf3 could sponge miR-452-5p, and the effect of circ_Arf3 overexpression was reversed by enhanced expression of miR-452-5p. Mbnl1 was a direct target of miR-452-5p. Knockdown of Mbnl1 abolished the suppressive effects of miR-452-5p inhibitor on proliferation and fibrosis-related protein expression in HG-treated MCs. Moreover, circ_Arf3 regulated Mbnl1 through miR-452-5p.

Conclusion

Overexpression of circ_Arf3 prevents cell proliferation and fibrous formation in HG-treated MCs by regulating the expression of Mbnl1 via miR-452-5p.

miR-452-5p suppressed the metastasis of Non-small cell lung cancer through regulating Moesin

Background: Non-small cell lung cancer (NSCLC) is a common malignant tumor, and it is characterized by high mortality. MicroRNA-452-5p (miR-452-5p) and Moesin (MSN) have been proved to be related with regulation of tumors. If miR-452-5p could regulate NSCLC through targeting MSN remain unclear. Methods: TargetScan data and GEPIA databases were used to predict binding site and analyze gene expression, respectively. EdU staining, wound healing, and Transwell assays were performed to measure cell proliferation, migration, and invasion, respectively. Results: The binding site between miR-452-5p and MSN was predicted and validated. Overexpression of miR-452-5p cell lines were constructed, and miR-452-5p mimics markedly inhibited the migration, invasion, and proliferation ability of both H322 and A549 cells, but these effects of miR-452-5p were reversed by pcDNA-MSN. pcDNA-MSN significantly reversed the influence of miR-452-5p mimics on the EMT related proteins expression in H322 and A549 cell lines by decreasing E-cadherin and increasing N-cadherin. Significant higher expression of MSN in lung adenocarcinoma and lung squamous cell carcinoma was observed through GEPIA and TCGA data base analysis. Higher expression of MSN is positively correlated with advanced lung cancer and suggests poor prognosis. Conclusions: We demonstrated that miR-452-5p modulated the cell proliferation, migration, invasion, and EMT process of H322 and A549 cell lines through targeting MSN. This research might provide a novel prevention and treatment target for NSCLC.

NF-κB Signaling Modulates miR-452-5p and miR-335-5p Expression to Functionally Decrease Epithelial Ovarian Cancer Progression in Tumor-Initiating Cells

Epithelial ovarian cancer (EOC) remains the fifth leading cause of cancer-related death in women worldwide, partly due to the survival of chemoresistant, stem-like tumor-initiating cells (TICs) that promote disease relapse. We previously described a role for the NF-κB pathway in promoting TIC chemoresistance and survival through NF-κB transcription factors (TFs) RelA and RelB, which regulate genes important for the inflammatory response and those associated with cancer, including microRNAs (miRNAs). We hypothesized that NF-κB signaling differentially regulates miRNA expression through RelA and RelB to support TIC persistence. Inducible shRNA was stably expressed in OV90 cells to knockdown RELA or RELB; miR-seq analyses identified differentially expressed miRNAs hsa-miR-452-5p and hsa-miR-335-5p in cells grown in TIC versus adherent conditions. We validated the miR-seq findings via qPCR in TIC or adherent conditions with RELA or RELB knocked-down. We confirmed decreased expression of hsa-miR-452-5p when either RELA or RELB were depleted and increased expression of hsa-miR-335-5p when RELA was depleted. Either inhibiting miR-452-5p or mimicking miR-335-5p functionally decreased the stem-like potential of the TICs. These results highlight a novel role of NF-κB TFs in modulating miRNA expression in EOC cells, thus opening a better understanding toward preventing recurrence of EOC.

Molecular Subtyping and Survival Analysis of Osteosarcoma Reveals Prognostic Biomarkers and Key Canonical Pathways

Osteosarcoma (OS) is a common bone malignancy in children and adolescents. Although histological subtyping followed by improved OS treatment regimens have helped achieve favorable outcomes, a lack of understanding of the molecular subtypes remains a challenge to characterize its genetic heterogeneity and subsequently to identify diagnostic and prognostic biomarkers for developing effective treatments. In the present study, global analysis of DNA methylation, and mRNA and miRNA gene expression in OS patient samples were correlated with their clinical characteristics. The mucin family of genes, MUC6, MUC12, and MUC4, were found to be highly mutated in the OS patients. Results revealed the enrichment of molecular pathways including Wnt signaling, Calcium signaling, and PI3K-Akt signaling in the OS tumors. Survival analyses showed that the expression levels of several genes such as RAMP1, CRIP1, CORT, CHST13, and DDX60L, miRNAs and lncRNAs were associated with survival of OS patients. Molecular subtyping using Cluster-Of-Clusters Analysis (COCA) for mRNA, lncRNA, and miRNA expression; DNA methylation; and mutation data from the TARGET dataset revealed two distinct molecular subtypes, each with a distinctive gene expression profile. Between the two subtypes, three upregulated genes, POP4, HEY1, CERKL, and seven downregulated genes, CEACAM1, ABLIM1, LTBP2, ISLR, LRRC32, PTPRF, and GPX3, associated with OS metastasis were found to be differentially regulated. Thus, the molecular subtyping results provide a strong basis for classification of OS patients that could be used to develop better prognostic treatment strategies.

MicroRNA-452: a double-edged sword in multiple human cancers

MicroRNAs (miRNAs) are small, noncoding RNAs with important functions in development, cell differentiation, and regulation of cell cycle and apoptosis. MiRNA expression is deregulated in various pathological processes including tumorigenesis and cancer progression through various mechanisms including amplification or deletion of miRNA genes, mutations, and epigenetic silencing and defects in the miRNA biogenesis machinery. Several studies have now shown abnormal miRNA profiles and proved their involvement in the initiation and progression of cancer. Since miR-452 has diverse roles (as suppressor or oncogene) in different cellular processes including epithelial-mesenchymal transition (EMT), proliferation, migration, and invasion, in this review we highlight a brief overview of the biological function and regulatory mechanism of miR-452 and its involvement as a potential biomarker for diagnosis and treatment of various cancer types.

LINC00589-dominated ceRNA networks regulate multiple chemoresistance and cancer stem cell-like properties in HER2+ breast cancer

Resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapy (trastuzumab), cancer stem cell (CSC)-like properties and multiple chemoresistance often concur and intersect in breast cancer, but molecular links that may serve as effective therapeutic targets remain largely unknown. Here, we identified the long noncoding RNA, LINC00589 as a key regulatory node for concurrent intervention of these processes in breast cancer cells in vitro and in vivo. We demonstrated that the expression of LINC00589 is clinically valuable as an independent prognostic factor for discriminating trastuzumab responders. Mechanistically, LINC00589 serves as a ceRNA platform that simultaneously sponges miR-100 and miR-452 and relieves their repression of tumor suppressors, including discs large homolog 5 (DLG5) and PR/SET domain 16 (PRDM16, a transcription suppressor of mucin4), thereby exerting multiple cancer inhibitory functions and counteracting drug resistance. Collectively, our results disclose two LINC00589-initiated ceRNA networks, the LINC00589-miR-100-DLG5 and LINC00589-miR-452-PRDM16- mucin4 axes, which regulate trastuzumab resistance, CSC-like properties and multiple chemoresistance of breast cancer, thus providing potential diagnostic and prognostic markers and therapeutic targets for HER2-positive breast cancer.

LINC01140 Targeting miR-452-5p/RGS2 Pathway to Attenuate Breast Cancer Tumorigenesis

Background

LINC01140 has been known to be involved in various cancers. However, its underlying molecular mechanism in breast cancer (BC) needs further exploration.

Methods

The LINC01140, miR-452-5p, and RGS2 levels in BC cells and tissues were evaluated by means of RT-qPCR and western blotting. The variations in the biological functions of BC cells were analyzed through CCK-8, transwell, western blotting, and xenograft experiments to observe cell viability, migration, levels of apoptosis-related proteins (Bax and Bcl-2), and tumor growth. The correlations existing among LINC01140, miR-452-5p, and RGS2 were validated through luciferase reporter and RIP assays.

Results

LINC01140 and RGS2 were remarkably downregulated in BC cells and tissues, whereas miR-452-5p was upregulated. LINC01140 overexpression diminished BC cell viability, migration, and tumor growth and facilitated apoptosis. MiR-452-5p upregulation enhanced cell viability and migration and suppressed apoptosis. Nevertheless, the additional upregulation of LINC01140 could reverse the promotive effects of miR-452-5p upregulation. Additionally, RGS2 overexpression inhibited the malignant phenotypes of BC cells, but miR-452-5p upregulation abolished this effect. In terms of mechanisms, LINC01140 acted as a miR-452-5p sponge. Moreover, RGS2 was determined to be miR-452-5p's downstream target gene in BC.

Conclusion

LINC01140 functioned as an antitumor agent in BC by sponging miR-452-5p to release RGS2. This hints that LINC01140 is a promising therapeutic target for BC.

Protein tyrosine kinase inhibitor resistance in malignant tumors: molecular mechanisms and future perspective

Protein tyrosine kinases (PTKs) are a class of proteins with tyrosine kinase activity that phosphorylate tyrosine residues of critical molecules in signaling pathways. Their basal function is essential for maintaining normal cell growth and differentiation. However, aberrant activation of PTKs caused by various factors can deviate cell function from the expected trajectory to an abnormal growth state, leading to carcinogenesis. Inhibiting the aberrant PTK function could inhibit tumor growth. Therefore, tyrosine kinase inhibitors (TKIs), target-specific inhibitors of PTKs, have been used in treating malignant tumors and play a significant role in targeted therapy of cancer. Currently, drug resistance is the main reason for limiting TKIs efficacy of cancer. The increasing studies indicated that tumor microenvironment, cell death resistance, tumor metabolism, epigenetic modification and abnormal metabolism of TKIs were deeply involved in tumor development and TKI resistance, besides the abnormal activation of PTK-related signaling pathways involved in gene mutations. Accordingly, it is of great significance to study the underlying mechanisms of TKIs resistance and find solutions to reverse TKIs resistance for improving TKIs efficacy of cancer. Herein, we reviewed the drug resistance mechanisms of TKIs and the potential approaches to overcome TKI resistance, aiming to provide a theoretical basis for improving the efficacy of TKIs.

The Overexpression of TOB1 Induces Autophagy in Gastric Cancer Cells by Secreting Exosomes

We previously confirmed that transducer of ERBB2, 1 (TOB1) gene, can induce autophagy in gastric cancer cells. Studies have shown the biogenesis of exosomes overlaps with different autophagy processes, which helps to maintain the self-renewal and homeostasis of body cells. This study is aimed at verifying whether overexpressing TOB1 induces autophagy by secreting exosomes in gastric cancer cells and its underlying mechanisms. Differential ultracentrifugation was used to extracted the exosomes from the culture medium of gastric cancer cell line AGS-TOB1 ectopically overexpressing TOB1 (exo-AGS-TOB1, experimental group) and AGS-empty-vector cell line with low expression of endogenous TOB1 (exo-AGS-Vector, control group). Exosomal markers CD9 and TSG101 were determined in both the cell supernatants of exo-AGS-TOB1 and exo-AGS-Vector by Western blot. Under the transmission electron microscope (TEM), the exosomes were round and saucer-like vesicles with double-layer membrane structure, and the vesicles showed different translucency due to different contents. The peak size of exosomes detected by nanoparticle tracking analysis (NTA) was about 100 nm. When the exosomes of exo-AGS-TOB1 and exo-AGS-Vector were cocultured with TOB1 knockdown gastric cancer cell line HGC-27-TOB1-6E12 for 48 hours, the conversion of autophagy-related protein LC3-I to LC3-II in HGC-27-TOB1-6E12 gastric cancer cells cocultured with exo-AGS-TOB1 was significantly higher than that in the control group, and the ratio of LC3-II/LC3-I was statistically different (P < 0.05). More autophagosomes in HGC-27-TOB1-6E12 cells cocultured with exo-AGS-TOB1 for 48 hours were observed under TEM, while fewer autophagosomes were found in the control group. Lastly, miRNAs were differentially expressed by cell supernatant-exosomal whole transcriptome sequencing. Thus, our results provide new insights into TOB1-induced autophagy in gastric cancer.

Non-coding RNAs and macrophage interaction in tumor progression

The macrophages are abundantly found in TME and their M2 polarization is in favor of tumor malignancy. On the other hand, non-coding RNAs (ncRNAs) can modulate macrophage polarization in TME to affect cancer progression. The miRNAs can dually induce/suppress M2 polarization of macrophages and by affecting various molecular pathways, they modulate tumor progression and therapy response. The lncRNAs can affect miRNAs via sponging and other molecular pathways to modulate macrophage polarization. A few experiments have also examined role of circRNAs in targeting signaling networks and affecting macrophages. The therapeutic targeting of these ncRNAs can mediate TME remodeling and affect macrophage polarization. Furthermore, exosomal ncRNAs derived from tumor cells or macrophages can modulate polarization and TME remodeling. Suppressing biogenesis and secretion of exosomes can inhibit ncRNA-mediated M2 polarization of macrophages and prevent tumor progression. The ncRNAs, especially exosomal ncRNAs can be considered as non-invasive biomarkers for tumor diagnosis.

MAGI2-AS3 restrains proliferation, glycolysis, and triggers apoptosis in acute lymphoblastic leukemia via regulating miR-452-5p/FOXN3 pathway

OBJECTIVES

MAGI2-AS3 is a cancer suppressor gene of multiple malignancies. Acute lymphoblastic leukemia (ALL) is an important type of leukemia that especially occurs in children. Our work evaluated the modulation of MAGI2-AS3 in ALL.

MATERIALS AND METHODS

qPCR and Western blotting were adopted for detection of target molecular expression. Growth and apoptosis were determined by CCK8 assay and Annexin V/PI staining. Glycolysis was detected by commercial kits. The direct binding between miR-452-5p and MAGI2-AS3 or FOXN3 was assessed by luciferase reporter assay. Tumor growth was measured in nude mice in vivo.

RESULTS

MAGI2-AS3 was down-regulated in ALL. Enforced expression of MAGI2-AS3 inhibited growth and glycolysis while promoting apoptosis of ALL cells. Moreover, MAGI2-AS3 up-regulated FOXN3 via sponging miR-452-5p. FOXN3 depletion abrogated MAGI2-AS3-mediated anti-cancer action. More importantly, MAGI2-AS3 repressed ALL cell growth in nude mice through regulation of miR-452-5p/FOXN3.

CONCLUSION

MAGI2-AS3 inhibits ALL development via modulating miR-452-5p/FOXN3.

Upregulation of SNTB1 correlates with poor prognosis and promotes cell growth by negative regulating PKN2 in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most highly malignant tumors and has a complicated pathogenesis. A preliminary study identified syntrophin beta 1 (SNTB1) as a potential oncogene in CRC. However, the clinical significance, biological function, and underlying mechanisms of SNTB1 in CRC remain largely unknown. Thus, the present study aimed to investigate the role of SNTB1 in CRC.

Methods

The expression profile of SNTB1 in CRC samples was evaluated by database analysis, cDNA array, tissue microarray, quantitative real-time PCR (qPCR), and immunohistochemistry. SNTB1 expression in human CRC cells was silenced using short hairpin RNAs (shRNA)/small interfering RNAs (siRNA) and its mRNA and protein levels were assessed by qPCR and/or western blotting. Cell viability, survival, cell cycle, and apoptosis were determined by the CCK-8 assay, colony formation, and flow cytometry assays, respectively. A xenograft nude mouse model of CRC was established to validate the roles of SNTB1 in vivo. Immunohistochemistry and TUNEL staining were used to determine the expression of SNTB1, PCNA, and cell apoptosis in tissue samples. Isobaric tag for relative and absolute quantification (iTRAQ) was used to analyze the differentially expressed proteins after knockdown of SNTB1 in CRC cells. Silence of protein kinase N2 (PKN2) using si-PNK2 was performed for rescue experiments.

Results

SNTB1 expression was increased in CRC tissues compared with adjacent noncancerous tissues and the increased SNTB1 expression was associated with shorter overall survival of CRC patients. Silencing of SNTB1 suppressed cell viability and survival, induced cell cycle arrest and apoptosis in vitro, and inhibited the growth of CRC cells in vivo. Further elucidation of the regulation of STNB1 on CRC growth by iTRAQ analysis identified 210 up-regulated and 55 down-regulated proteins in CRC cells after SNTB knockdown. A PPI network analysis identified PKN2 as a hub protein and was up-regulated in CRC cells after SNTB1 knockdown. Western-blot analysis further confirmed that SNTB1 knockdown significantly up-regulated PKN2 protein expression in CRC cells and decreased the phosphorylation of both ERK1/2 and AKT. Moreover, rescue experiments indicated that PKN2 knockdown significantly rescued SNTB1 knockdown-mediated decrease in cell viability, survival, and increase of cell cycle arrest at G0/G1 phase and apoptosis of CRC cells.

Conclusions

These findings indicate that SNTB1 is overexpressed in CRC. Elevated SNTB1 levels are correlated with shorter patient survival. Importantly, SNTB1 promotes tumor growth and progression of CRC, possibly by reducing the expression of PKN2 and activating the ERK and AKT signaling pathway. Our study highlights the potential of SNTB1 as a new prognostic factor and therapeutic target for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02246-7.