Cell specific tumor suppressor effect of Hsa-miR-1226-3p through downregulation of HER2, PIK3R2, and AKT1 genes

In-silico and in-vitro evidence suggest LINC01405 as a sponge for miR-29b and miR-497-5p, and a potential regulator of Wnt, PI3K, and TGFB signaling pathways in breast carcinoma

BACKGROUND

Carcinoma of the breast, a prevailing factor in female mortality worldwide, involves dysregulation of lncRNAs and microRNAs.

AIM

The main goal of this research was to predict and experimentally examine the LINC01405 expression status in breast cancer subtypes, along with investigation of its interaction with miR-29b and miR-497-5p that results in regulating PI3-Kinase, WNT, and TGF-beta signaling pathways.

METHODS AND RESULTS

We performed a meta-analysis of five GEO datasets, encompassing microarray and RNA-seq data, to identify differentially expressed genes. The Cancer Genome Atlas transcriptome dataset was also analyzed to determine essential gene modules, associated with different stages of breast cancer by weighted gene co-expression networks. In addition, networks of drug-gene interactions were constructed to explore potential treatment options. LINC01405 as a microRNA sponge was chosen and examined. furthermore, downstream target genes were discovered. Experimental validation consisted of plasmid constructs used in cell culture experiments, RT-qPCR for expression analysis, and cell cycle assays. Our bioinformatics findings showed higher LINC01405 expression in Basal-like triple-negative breast carcinoma. In contrast, lower expression in Luminal samples was observed compared with normal samples, which was consistently observed in both breast cancer tissues and cell lines. LINC01405 expression level was correlated with miR-29b and miR-497 levels. The MDA-MB-231 cell line demonstrated higher LINC01405 expression and lower miR-29b and miR-497 expression levels. However, SKBR3 and MCF7 cells had lower LINC01405 expression and higher miR-29b and miR-497 levels, suggesting a regulatory role for LINC01405 as a competing endogenous RNA. This was experimentally confirmed when LINC01405 was overexpressed in SKBR3 cells, and the common target genes of miR-29b and miR-497 were upregulated. Additionally, LINC01405 upregulation led to the increased cell populations, proliferation, and upregulation of critical cancer-related genes, including AKT1, AKT3, mTOR, WNT3A, SMAD3, CYCLIN D1, CYCLIN D2, BCL2, and GSK3B.

CONCLUSION

We revealed the differential expression of LINC01405 in several types of breast cancer and its role in regulating signaling pathways, potentially via scavenging miRNAs. These findings clarified the role of LINC01405 in breast cancer development and identified potential therapeutic targets.

SPTBN1 attenuates rheumatoid arthritis synovial cell proliferation, invasion, migration and inflammatory response by binding to PIK3R2

BACKGROUND

As an autoimmune systemic disorder, rheumatoid arthritis (RA) features chronic inflammation as well as synovial infiltration of immune cells. This study was designed with the purpose of discussing the hidden mechanism of SPTBN1 and exploring favorable molecular-targeted therapies.

METHODS

With the application of RT-qPCR and western blot, the expressions of SPTBN1 and PIK3R2 before or after transfection were estimated. Besides, Cell Counting Kit-8, Edu, wound healing, transwell, enzyme-linked immunosorbent assay, and TUNEL were adopted for the evaluation of the viability, proliferation, migration, invasion, inflammatory response, and apoptosis of fibroblast-like synoviocyte (FLS). In addition, the interaction of SPTBN1 and PIK3R2 was testified by applying immunoprecipitation (IP) and western blot was utilized for the assessment of migration-, apoptosis-, and PI3K/AKT signal-related proteins.

RESULTS

It was discovered that SPTBN1 declined in RA synovial cells and its overexpression repressed the proliferation, migration, invasion, and inflammation of RA-FLSs but promoted apoptosis. IP confirmed that SPTBN1 could bind to PIK3R2 in FLSs. To further figure out the hidden mechanism of SPTBN1 in RA, a series of functional experiments were carried out and the results demonstrated that the reduced expressions of MMP2, MMP9, IL-8, IL-1β, IL-6, and Bcl2 as well as increased levels of Bax and cleaved caspase3 in SPTBN1-overexpressed RA-FLSs were reversed by PIK3R2 depletion, revealing that SPTBN1 repressed the migration and inflammation and promoted the apoptosis of RA-FLSs via binding to PIK3R2. Results obtained from western blot also revealed that PIK3R2 interference ascended the contents of p-PI3K and p-AKT in SPTBN1-overexpressed RA-FLSs, implying that SPTBN1 repressed PI3K/AKT signal in RA via PIK3R2.

DISCUSSION

SPTBN1 alleviated the proliferation, migration, invasion, and inflammation in RA via interacting with PIK3R2.

Network pharmacology-based analysis of the mechanism of Saposhnikovia divaricata for the treatment of type I allergy

CONTEXT

Saposhnikovia divaricata (Turcz.) Schischk (Apiaceae) (SD) has various pharmacological activities, but its effects on type I allergy (TIA) have not been comprehensively studied.

OBJECTIVE

This study evaluates the treatment and molecular mechanisms of SD against TIA.

MATERIALS AND METHODS

The effective components and action targets of SD were screened using TCMSP database, and allergy-related targets of SD were predicted using GeneCards and OMIM database. The obtained target intersections were imported into David database for GO analysis, and used R software to perform KEGG analysis. The RBL-2H3 cells sensitised by DNP-IgE/DNP-BSA were treated with different concentrations of SD (root decoction, 0.5, 1, and 2 mg/mL), prim-O-glucosylcimifugin (POG, 10, 40, and 80 μg/mL) and the positive control drug-ketotifen fumarate (KF, 30 μM) for 12 h, then subjected to cell degranulation and qPCR analysis.

RESULTS

Eighteen active compounds of SD and 38 intersection targets were obtained: TIA-related signal pathways mainly include calcium signal pathway, PI3K-Akt signal pathway and MAPK signal pathway. Taking the β-Hex release rate of the model group as the base, the release rate of SD and POG in high dose groups were 43.79% and 57.01%, respectively, which were significantly lower than model group (p < 0.01), and significantly lower than KF group (63.83%, p < 0.01, p < 0.05). SD and POG could down-regulate the expression of related proteins in the Lyn/Syk, PI3K/AKT and MAPK signalling pathways.

DISCUSSION AND CONCLUSION

Saposhnikovia divaricata could inhibit IgE-induced degranulation of mast cells, providing a scientific basis for further research and clinical applications of SD in TIA treatment.

ErbB4-encoded novel miRNAs act as tumor suppressors by regulating ErbB/PI3K signaling

BACKGROUND: ErbB/PI3K signaling is widely recognized as a critical modulator of malignancy and miRNAs have been found to play a crucial role in the regulation of this pathway. OBJECTIVE: This study aimed to identify novel miRNAs related to the ErbBs loci and investigate the functional effects of these miRNAs on ErbB/PI3K signaling in cancer progression. MATERIALS and METHODS: Bioinformatics tools and RNA-seq data were used to discover novel miRNAs in breast and colon cancer cells. Gene expression levels were determined using RT-qPCR. Western blotting and dual-luciferase assays were used to identify the regulatory mechanism between ErbB4-miR1/2 and related genes. The effects of ErbB4-miR1/2 on cell proliferation, viability, ROS production, and migration were assessed by PI-flow cytometry, colony formation, MTT, ROS, scratch, and transwell assays in SKBR3 and SW480 cells. RESULTS: MicroRNA prediction tools, RNA-seq data, RT-qPCR, and sequencing results identified ErbB4-miR1 and ErbB4-miR2 (ErbB4-miR1/2) as novel miRNAs encoded by ErbB4 gene. ErbB4-miR1/2 were downregulated in breast and colon tumor tissues and also in different cancerous cells. RT-qPCR and dual-luciferase assays revealed that ErbB2 and ErbB3 genes are regulated by ErbB4-miR1/2. Consistently, a decrease in the p-AKT/AKT protein ratio verified the suppressive effect of ErbB4-miR1/2 on ErbB/PI3K activity. Furthermore, ErbB4-miR1/2 overexpression suppressed cell proliferation, viability, and migration, and increased ROS production. CONCLUSIONS: ErbB4-miR1/2 are novel tumor suppressor miRNAs which attenuate ErbB/PI3K signaling in breast and colon cancer cells.

B-Cell Translocation Gene 2 Upregulation Is Associated with Favorable Prognosis in Lung Adenocarcinoma and Prolonged Patient Survival

The tumor suppressor protein B-cell translocation gene 2 (BTG2) is downexpressed in lung adenocarcinoma (LUAD); however, its role in LUAD survival remains unknown. This investigation is aimed at exploring the activity of BTG2 in LUAD. We analyzed BTG2 expression in LUAD datasets of the TCGA database and examined that BTG2 was markedly downregulated in comparison with adjacent normal tissues. The prognostic analysis suggested that higher expression of BTG2 protein correlates with prolonged survival in patients. Vectors expressing BTG2 were stably transduced into lung adenocarcinoma A549 cells. The overexpression of BTG2 in A549 cells causes cellular G1 phase arrest but did not affect cell proliferation, accompanied by increased activation of NF-κB. Our data indicate that BTG2 overexpression may trigger an autoregulatory prosurvival NF-κB pathway, which is resistant to environmental intervention owing to an increased level of BTG2.

miR-31-3p functions as a tumor suppressor by directly targeting GABBR2 in prostate cancer

MicroRNAs are key regulators of gene expression in tumorigenesis. In this study, we investigated the tumor-suppressive function of miR-31-3p. Analysis of the Gene Expression Omnibus database revealed that the expression of miR-31-3p in prostate cancer tissues is lower than that in adjacent normal tissues from patients with prostate cancer. Moreover, miR-31-3p induces apoptosis in DU145, PC-3, and LNCap prostate cancer cells, while those transfected with miR-31-3p exhibit significantly decreased cell proliferation, migration, invasiveness, and tumor sphere-forming ability, as determined using the cell counting kit-8, transwell, and sphere-forming assays. Further analysis revealed that GABBR2 is a direct target of miR-31-3p. Within a DU145 xenograft murine model, intratumoral injection of a miR-31-3p mimic suppresses tumor growth. Taken together, the findings of this study suggest that miR-31-3p performs a novel tumor-suppressive function in prostate cancer and may represent a novel target for anti-prostate cancer miRNA therapeutics.

Senescent Human Pancreatic Stellate Cells Secrete CXCR2 Agonist CXCLs to Promote Proliferation and Migration of Human Pancreatic Cancer AsPC-1 and MIAPaCa-2 Cell Lines

Interactions between pancreatic cancer cells and pancreatic stellate cells (PSCs) play an important role in the progression of pancreatic cancer. Recent studies have shown that cellular senescence and senescence-associated secretory phenotype factors play roles in the progression of cancer. This study aimed to clarify the effects of senescence-induced PSCs on pancreatic cancer cells. Senescence was induced in primary-cultured human PSCs (hPSCs) through treatment with hydrogen peroxide or gemcitabine. Microarray and Gene Ontology analyses showed the alterations in genes and pathways related to cellular senescence and senescence-associated secretory phenotype factors, including the upregulation of C-X-C motif chemokine ligand (CXCL)-1, CXCL2, and CXCL3 through the induction of senescence in hPSCs. Conditioned media of senescent hPSCs increased the proliferation—as found in an assessment with a BrdU incorporation assay—and migration—as found in an assessment with wound-healing and two-chamber assays—of pancreatic cancer AsPC-1 and MIAPaca-2 cell lines. SB225002, a selective CXCR2 antagonist, and SCH-527123, a CXCR1/CXCR2 antagonist, attenuated the effects of conditioned media of senescent hPSCs on the proliferation and migration of pancreatic cancer cells. These results suggest a role of CXCLs as senescence-associated secretory phenotype factors in the interaction between senescent hPSCs and pancreatic cancer cells. Senescent PSCs might be novel therapeutic targets for pancreatic cancer.

Clinical Potential of lncRNA PPP1R26-AS1 in Breast Cancer and Its Contribution to Cancer Progression

Breast cancer has become the most leading diagnosed tumor worldwide in 2020. In this study, the biomarker potential and influence on the cellular function of lncRNA PPP1R26-AS1 was investigated in breast cancer. Expression levels of lncRNA PPP1R26-AS1 in breast tissues and cells were detected by RT-qPCR. Association between lncRNA PPP1R26-AS1 level and clinical parameters was investigated by Chi-square analysis. The prognostic potential was assessed by Kaplan-Meier and multivariate Cox regression analysis. Knockdown of lncRNA PPP1R26-AS1 was subjected to study the effect on cell proliferation, invasion, and migration by CCK-8 and transwell assay. The bind between PPP1R26-AS1 and miR-1226-3p was investigated. LncRNA PPP1R26-AS1 was highly expressed in breast tissues and cell lines. This upregulation was correlated with pTNM, positive ER status, luminal B subtype, positive nodal status, and shorter overall survival in breast cancer patients. Significant decreases in proliferation, migration, and invasion activity were observed upon knockdown of lncRNA PPP1R26-AS1. lncRNA PPP1R26-AS1 could act as ceRNA to bind with miR-1226-3p in breast cancer. LncRNA PPP1R26-AS1, as oncogenic lncRNA, could provide a new perspective on the development of prognostic biomarkers and a new approach in tailoring the treatment personalized in breast cancer.

Splice and Dice: Intronic microRNAs, Splicing and Cancer

Introns span only a quarter of the human genome, yet they host around 60% of all known microRNAs. Emerging evidence indicates the adaptive advantage of microRNAs residing within introns is attributed to their complex co-regulation with transcription and alternative splicing of their host genes. Intronic microRNAs are often co-expressed with their host genes, thereby providing functional synergism or antagonism that is exploited or decoupled in cancer. Additionally, intronic microRNA biogenesis and the alternative splicing of host transcript are co-regulated and intertwined. The importance of intronic microRNAs is under-recognized in relation to the pathogenesis of cancer.

Biogenesis, characterization, and functions of mirtrons

MicroRNAs (miRNAs) are major post-transcriptional regulators of gene expression. They base pair with the complementary target mRNA at the 3'UTR and modulate cellular processes by repressing the mRNA translation or degrading the mRNA. There are well-documented mechanisms of biogenesis of miRNA; however, a sizeable number of miRNAs are also produced by non-canonical pathways. Mirtrons represent a predominant class of non-canonical miRNAs. Mirtrons originate from intronic regions and are produced in a splicing-dependent and Drosha-independent manner. Mirtrons constitute about 15% of all miRNAs produced in a human body and have caught attention of researchers worldwide due to their unconventional origin, sequence characteristics, evolutionary dynamics, ability to regulate variety of cellular processes and their immense potential in disease therapeutics. In this comprehensive review we collate the research done in the past decade including biogenesis, sequence characteristics, regulation, and emerging therapeutic roles of mirtrons. This article is categorized under: RNA Processing > Processing of Small RNAs Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action.