miR‑425‑5p is associated with poor prognosis in patients with breast cancer and promotes cancer cell progression by targeting PTEN

MiR-425-5p suppression of Crebzf regulates oocyte aging via chromatin modification

Female infertility due to declining oocyte quality with age remains a significant challenge for patients and physicians, despite extensive research efforts. Recent studies suggest that microRNAs (miRNAs), which respond to various stressors in the aging process, may provide a promising solution. With the approval of small RNA drugs for clinical use, miRNA-based treatment of oocyte aging appears to be a viable option. Through high-throughput sequencing, miR-425-5p was identified as the only miRNA elevated under natural aging and oxidative stress. Microinjection of inhibitors to inhibit miR-425-5p effectively improved compromised phenotypes of old oocytes in vitro. Further investigation revealed that Crebzf acts as a mediator of miR-425-5p's age-related functions in old oocytes. In vivo treatment with miR-425-5p antagomirs significantly improved impaired oocyte development in reproductively old females by targeting Crebzf. Single-cell RNA sequencing revealed that Crebzf plays a vital role in regulating mRNAs targeting histone H3, trimethylated lysine 4 (H3K4me3), a crucial marker for transcriptional silencing. Overexpression of miR-425-5p could hinder oocyte maturation by downregulating Crebzf expression and disrupting transcriptional regulation. Our findings provide new insights into the potential of miR-425-5p antagomirs as a treatment for female infertility and highlight an elegant mechanism by which miR-425-5p inhibition of Crebzf inhibits a developmental switch in GV oocytes by regulating a group of histone methyltransferase mRNAs.

Long noncoding RNA LINC00858 aggravates the progression of esophageal squamous cell carcinoma via regulating the miR-425-5p/ABL2 axis

Esophageal squamous cell carcinoma (ESCC) is one of the most fatal cancers with high morbidity and mortality, which severely affects people's lives. Long intergenic non-protein coding RNA 858 (LINC00858) was confirmed to promote the progression of colorectal cancer and lung cancer. However, the role of lncRNA LINC00858 is still unknown in ESCC. Herein, the main purpose of research was to explore LINC00858 function and its impact on ESCC cell biological behaviors. RT-qPCR was used to test the expression of LINC00858, miR-425-5p and ABL proto-oncogene 2 (ABL2) in ESCC cells. Functional experiments such as EdU assay, CCK-8 assay, transwell assay and Western blot assay were conducted to investigate the biological behaviors of ESCC cells. Luciferase reporter assay and RIP assay were implemented to determine the binding situation among RNAs. LINC00858 expression was abnormally high in ESCC cells and down-regulation of LINC00858 could restrain the proliferation, invasion, migration and EMT process of ESCC cells. Furthermore, miR-425-5p was proved to be sponged by LINC00858 and was down-regulated in ESCC cells. Besides, we discovered that miR-425-5p could target ABL2. Moreover, knockdown of ABL2 reversed the promoting function of miR-425-5p inhibitor on ESCC progression. LINC00858 aggravated ESCC progression via regulating the miR-425-5p/ABL2 axis.

Correlation of PTEN signaling pathway and miRNA in breast cancer

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

LINC00969 inhibits proliferation with metastasis of breast cancer by regulating phosphorylation of PI3K/AKT and ILP2 expression through HOXD8

Background

Breast cancer (BC) is a malignancy that is inadequately treated and poses a significant global health threat to females. The aberrant expression of long noncoding RNAs (lncRNAs) acts as a complex with a precise regulatory role in BC progression. LINC00969 has been linked to pyroptotic cell death and resistance to gefitinib in lung cancer cells. However, the precise function and regulatory mechanisms of LINC00969 in BC remain largely unexplored.

Methods

Cell proliferation, migration, and invasion of BC cells were evaluated using CCK-8 and Transwell assays. Western blotting was employed to analyze the protein expression levels of HOXD8, ILP2, PI3K, t-AKT, and p-AKT.

Results

LINC00969 was drastically reduced in BC tissues LINC00969 overexpression markedly suppressed proliferation, migration, and invasion, and blocked PI3K and p-AKT protein expression in MCF-7 cells. Activation of the PI3K/AKT pathway reversed the suppressive effect of LINC0096 overexpression on the proliferation, migration, and invasion of MCF-7 cells. Moreover, LINC00969 overexpression enhanced HOXD8 and blocked ILP2 protein expression in MCF-7 cells. In contrast, activating the PI3K/AKT pathway had no effect on HOXD8 and blocked ILP2 protein expression in MCF-7 cells overexpressing LINC00969. HOXD8 knockdown enhanced ILP2, PI3K, and p-AKT protein expression, and the proliferation, migration, and invasion of MCF-7 cells co-transfected with si-HOXD8 and ov-LINC00969. LINC00969 regulated HOXD8 via binding to miR-425-5p.

Conclusion

LINC00969 inhibits the proliferation and metastasis of BC cells by regulating PI3K/AKT phosphorylation through HOXD8/ILP2.

MiR-101-3p targets KPNA2 to inhibit the progression of lung squamous cell carcinoma cell lines

We herein discuss the impacts of miR-101-3p on the tumorigenesis-related cell behaviors in lung squamous cell carcinoma (LUSC) by repressing KPNA2. TCGA database was utilized to measure miR-101-3p and KPNA2 levels in LUSC tissues and cells. The interaction of miR-101-3p and KPNA2-3'UTR was determined by dual luciferase assay. Western blot evaluated the protein level of KPNA2. MiR-101-3p was under-expressed in LUSC cells while KPNA2 was overexpressed. Western blot confirmed the impact of KPNA2 expression on cancer cell progression. The negative regulatory impact of miR-101-3p on KPNA2 was also verified. In vitro cell function assays revealed the suppressing effect of high miR-101-3p expression on cell invasion, migration and viability, as well as its promoting effect on apoptosis. Up-regulated miR-101-3p weakened the promoting effect of overexpressed KPNA2 on LUSC malignant progression. To conclude, miR-101-3p repressed viability, invasion, and migration, and facilitated cell apoptosis in LUSC by suppressing KPNA2.

SDF-1 and NOTCH signaling in myogenic cell differentiation: the role of miRNA10a, 425, and 5100

BACKGROUND

Skeletal muscle regeneration is a complex process regulated by many cytokines and growth factors. Among the important signaling pathways regulating the myogenic cell identity are these involving SDF-1 and NOTCH. SDF-1 participates in cell mobilization and acts as an important chemoattractant. NOTCH, on the other hand, controls cell activation and myogenic determination of satellite cells. Knowledge about the interaction between SDF-1 and NOTCH signaling is limited.

METHODS

We analyzed two populations of myogenic cells isolated from mouse skeletal muscle, that is, myoblasts derived from satellite cells (SCs) and muscle interstitial progenitor cells (MIPCs). First, microRNA level changes in response to SDF-1 treatment were analyzed with next-generation sequencing (NGS). Second, myogenic cells, i.e., SC-derived myoblasts and MIPCs were transfected with miRNA mimics, selected on the basis of NGS results, or their inhibitors. Transcriptional changes, as well as proliferation, migration, and differentiation abilities of SC-derived myoblasts and MIPCs, were analyzed in vitro. Naive myogenic potential was assessed in vivo, using subcutaneous engrafts and analysis of cell contribution to regeneration of the skeletal muscles.

RESULTS

SDF-1 treatment led to down-regulation of miR10a, miR151, miR425, and miR5100 in myoblasts. Interestingly, miR10a, miR425, and miR5100 regulated the expression of factors involved in the NOTCH signaling pathway, including Dll1, Jag2, and NICD. Furthermore, miR10a, miR425, and miR5100 down-regulated the expression of factors involved in cell migration: Acta1, MMP12, and FAK, myogenic differentiation: Pax7, Myf5, Myod, Mef2c, Myog, Musk, and Myh3. However, these changes did not significantly affect myogenic cell migration or fusion either in vitro or in vivo, except when miR425 was overexpressed, or miR5100 inhibitor was used. These two molecules increased the fusion of MIPCs and myoblasts, respectively. Furthermore, miR425-transfected MIPC transplantation into injured skeletal muscle resulted in more efficient regeneration, compared to control cell transplantation. However, skeletal muscles that were injected with miR10a transfected myoblasts regenerated less efficiently.

CONCLUSIONS

SDF-1 down-regulates miR10a, miR425, and miR5100, what could affect NOTCH signaling, differentiation of myogenic cells, and their participation in skeletal muscle regeneration.

Diverse Functions of MiR-425 in Human Cancer

miRNAs are a type of small endogenous noncoding RNA composed of 20-22 nucleotides that can regulate gene expression by targeting the 3' untranslated region of mRNA. Many investigations have discovered that miRNAs have a role in the development and progression of human cancer. Several aspects of tumor development are affected by miR-425, including growth, apoptosis, invasion, migration, epithelial-mesenchymal transition, and drug resistance. In this article, we discuss the properties and research development of miR-425, focusing on the regulation and function of miR-425 in various cancers. Furthermore, we discuss the clinical implications of miR-425. This review may broaden our horizon for better understanding the role of miR-425 as biomarkers and therapeutic targets in human cancer.

Breast Cancer Exosome-Derived miR-425-5p Induces Cancer-Associated Fibroblast-Like Properties in Human Mammary Fibroblasts by TGFβ1/ROS Signaling Pathway

The connection between the cellular microenvironment and tumor cells is crucial for tumor progression. However, the process by which normal fibroblasts (NFs) become cancer-associated fibroblasts (CAFs) is unknown, and mounting evidence suggests that some microRNAs (miRNAs) have an important role in converting NFs into CAFs. Breast cancer (BC) has been proven to have enhanced miR-425-5p expression in order to support progression. We discovered that human mammary fibroblasts (HMFs) could uptake BC cell line-derived exosomes to change their properties, promoting the switch to the CAF phenotype and increasing cell motility, as evidenced by an increase in CAF activation-related marker protein expression and cell proliferation, invasion, and migration. Transfection of exosomes is obtained from BC cells, and miR-425-5p inhibitors suppressed the aforementioned effects as well as lowered chemokine levels and gene expression related with proliferation and metastasis. By suppressing the expression of its target gene TGFβRII (TGFβ1 receptor), miR-425-5p enhanced the transition of HMFs to the CAF phenotype. MDA-MB-231 cells and CAFs stimulated by HMF absorption of MDA-MB-23-derived exosomes showed similar proliferation, invasion, migration, and expression of -SMA, FAP, CXCL1, IL-6, TGFβ1, P21, P27, Ki67, vimentin, E-cadherin, N-cadherin, α-catenin, fibronectin, and MMP-2. TGFβ1 overexpression enhanced ROS production. Finally, we found that HMFs transiently transfected with miR-425-5p can promote tumor growth in vivo. Finally, these findings provide fresh insight on miR-425-5p as an important mediator of the interaction between BC cells and stroma.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2

BACKGROUND

Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS).

METHODS

The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment.

RESULTS

In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter.

CONCLUSION

NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

Identification of differentially expressed microRNAs as potential biomarkers for carcinoma ex pleomorphic adenoma

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignancy that transforms from PA. Early detection of the carcinoma by biopsy is difficult due to similar histopathology of the malignant and benign components. To address this, we investigated and compared the characteristic miRNA expression patterns across samples of the PA, carcinomatous portions (CA) of CXPA, as well as conventional PA. We selected 13 CXPA and 16 conventional PA FFPE samples, separated the PA and CA portions of CXPA samples and conducted miRNA profiling for each group. Among 13 transcripts that were differentially expressed between PA and CA of CXPA, eight miRNAs were up-regulated and five down-regulated in CA. Bioinformatic analysis revealed that the up-regulated miRNAs were related to cancer progression and down-regulated ones to tumor suppression. Additionally, seven miRNAs were significantly up-regulated in PA of CXPA compared to conventional PA, although they are histopathologically similar. Almost all of these transcripts interacted with TP53, a well-known tumor suppressor. In conclusion, we identified differentially expressed miRNAs in PA and CA of CXPA, which were closely associated with TP53 and various cancer-related pathways. We also identified differentially expressed miRNAs in the PA of CXPA and conventional PA which may serve as potential biomarkers.

Bioinformatics analysis of downstream circRNAs and miRNAs regulated by Runt-related transcription factor 1 in papillary thyroid carcinoma

BACKGROUND

This study sought to clarify the role of Runt-related transcription factor 1's (RUNX1's) regulation of downstream circular ribonucleic acid (circRNA) in the occurrence and development of papillary thyroid carcinoma (PTC) and to explore its mechanism of action.

METHODS

The levels of RUNX1 were analyzed in PTC tumor tissues and adjacent non-tumor tissues in different types and at different stages via reverse-transcription quantitative polymerase chain reaction (RT-qPCR). The expression pattern and functional role of RUNX1 were analyzed in PTC cells via RT-qPCR, Western blotting, and Transwell assays. This study explored the differential expression of circRNA and microRNA (miRNA) in cells after knocking down RUNX1 through high-throughput sequencing and examined the changes in downstream signaling pathways through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses.

RESULTS

RUNX1 was upregulated in PTC tissues, and the expression levels of RUNX1 were related to PTC stage. The knockdown of RUNX1 inhibited the proliferation, migration, and invasion of cells. The high-throughput sequencing results showed that after RUNX1 knockdown, 29 circRNAs (11 upregulated and 18 downregulated) and 20 miRNAs (8 upregulated and 12 downregulated) had the most significant differential expression. The GO analysis of the differential circRNA downstream genes showed that the iron channel-related pathways, endosomal transport, learning, and memory pathways had the largest number of differential genes, and the most significant changes. The KEGG analysis showed that there were 2 pathways with P values <0.05; that is, the glycosaminoglycan synthesis and transcription dysregulation pathways. The GO analysis of the differential miRNA downstream genes showed that the protein binding and cytoplasmic pathways had the largest number of differential genes and the greatest level of difference. The KEGG analysis showed that the tumor-related pathways, phosphatidylinositol-3-kinase and protein kinase B, glycoprotein, cytoskeleton, Ras, and Rap1 pathways changed the most significantly.

CONCLUSIONS

RUNX1 is highly expressed in PTC. We conducted high-throughput sequencing to analyze the effect of knocking down RUNX1 on the levels of circRNA and miRNA in PTC. The GO and KEGG analyses revealed that the iron channel-related pathways, endosomal transport, learning and memory, glycosaminoglycan synthesis, and transcriptional disorder-related signaling pathways were enriched.

Clinical Values and Underlying Mechanism Analysis of Serum miR-455-5p in Carotid Artery Stenosis

Purpose

Carotid artery stenosis (CAS) is a leading cause of cerebral infarction, its early diagnosis and intervention are necessary. In light of the important role of microRNAs (miRNAs) in cerebrovascular disease, this study aimed to investigate the expression pattern and clinical significance of serum miR-455-5p in the onset and development of CAS, as well as its underlying mechanism.

Patients and Methods

Seventy patients with asymptomatic CAS were recruited, and the development of cerebral ischemia events (CIEs) was recorded during the five-years follow-up. qRT-PCR was performed for the serum miR-455-5p detection. ROC curve was applied for the diagnostic ability evaluation. By constructing multivariable logistic or cox regression model, odds ratio (OR) or hazard ratio (HR) were calculated to assess the impact of each risk factor on independent variables. Human aortic endothelial cells (HAECs) were treated with ox-LDL to induce endothelial cell damage. The role of miR-455-5p in the cell viability, apoptosis, oxidative stress and inflammatory response was detected.

Results

Serum miR-455-5p showed low expression in cases with CAS, and had an independent influence on the degree of CAS. The diagnostic ability of serum miR-455-5p to diagnose CAS was determined via ROC curve, with the AUC of 0.927. During follow-up, patients with low miR-455-5p expression showed high incidence of CIEs. In multivariable cox regression model, degree of CAS and miR-455-5p were significant risk factors for the development of CIEs in the CAS patients. In vitro, miR-455-5p was at a low expression in HAECs cell models and can prevent cells from ox-LDL induced cell apoptosis, oxidative stress and inflammatory response. SOCS3 was a target gene of miR-455-5p and upregulated in ox-LDL treated cells.

Conclusion

Down-regulated expression of serum miR-455-5p is hopeful to be used as a biomarker for the early diagnosis of CAS. MiR-455-5p is an independent risk factor for the degree of CAS, and has a certain predictive value for the development of CIEs. That might be associated with the protective role of miR-455-5p against ox-LDL-induced endothelial cell injury via targeting SOCS3.

Cytochrome b561 Serves as a Potential Prognostic Biomarker and Target for Breast Cancer

PURPOSE

Cytochrome b561 (CYB561) is a transmembrane protein and participates in ascorbate recycling and iron homeostasis. However, its role in breast cancer remains unclear.

PATIENTS AND METHODS

In this study, we explored the expression pattern and prognostic value of CYB561 in breast cancer through The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), PrognoScan and Kaplan-Meier Plotter and confirmed its mRNA expression in human breast cell lines. LinkedOmics, Metascape and Gene Expression Profiling Interactive Analysis (GEPIA2) databases were applied to investigate the co-expression genes and construct microRNA (miRNA) networks associated with CYB561. The correlations between CYB561 and immune infiltration cells and genes were also illustrated.

RESULTS

The CYB561 expression was upregulated in breast cancer tissues and cell lines and significantly correlated with the clinical features of breast cancer patients. High CYB561 expression was associated with poor survival and was an independent risk factor for overall and disease-specific survival. Functional enrichment analysis showed that CYB561 and its co-expressed genes were mainly enriched in lipid biosynthetic process, Wnt signaling pathway, Hippo signaling pathway, etc. The miRNA network analysis suggested that hsa-miR-497 was negatively correlated with CYB561 expression and was predicted to direct target CYB561. CYB561 expression was positively correlated with infiltrating levels of CD4+ T cells, neutrophils and dendritic cells in breast cancer. Subsequent analysis found that B cells could predict the outcome of breast cancer. Also, CYB561 showed strong correlations with diverse immune marker sets in breast cancer.

CONCLUSION

CYB561 may serve as a potential prognostic biomarker and target for breast cancer. Our findings laid foundation for future research on molecular mechanisms of CYB561 in breast cancer.

miRNA-425-5p enhances diffuse large B cell lymphoma growth by targeting PTEN

BACKGROUND

At present, cancer is one of the greatest threats to mankind, and is associated with the highest rates of morbidity and comorbidity. Recently, the advancements in molecular biology have led to an in-depth understanding of the underlying pathophysiology, which may further impact the lead time in the context of early discovery and effective therapy of cancer. Therefore, the present study proposes a better understanding of the role of micro(miR)-425-5p in diffuse large B-cell lymphoma (DLBC).

METHODS

qRT-PCR was carried out to detect the relevant proteins, miRNA and mRNA RNA gene expression in DLBC cells. The effect of miR-425-5p on DLBC growth was examined by CCK-8 and colony formation assays. The binding relationship between genes was verified by dual-luciferase reporter gene assay.

RESULTS

We demonstrated how the over-expression of miR-425-5p can lead to increased progression of DLBC by increasing the cellular proliferation rate and colony-forming ability. Additionally, we also found that the expression of miR-425-5p could be significantly inhibited on the basis of phosphatase and tensin homolog (PTEN) signaling pathways.

CONCLUSIONS

The present study concludes that miR-425-5p is responsible for the oncogenic progression and relapse of DLBC tumorigenesis via PTEN/PI3K signaling, which can thus be effectively used to achieve better therapeutic outcomes.

LncRNA-MSC-AS1 inhibits the ovarian cancer progression by targeting miR-425-5p

BACKGROUND

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) were reported to be aberrantly expressed and related to the pathogenesis of ovarian cancer. However, the role and regulatory mechanism of MSC-AS1 in ovarian cancer has yet to be fully elucidated.

METHODS

Expression of lncRNA MSC-AS1 (MSC-AS1) and microRNA-425-5p (miR-425-5p) in the ovarian cancer tissue samples and cell lines was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The functions of MSC-AS1 on ovarian cancer cell proliferation, cell cycle and apoptosis were determined using MTT, colony formation and flow cytometry analyses. The protein expression levels were evaluated using western blot assay. The targeting relationship MSC-AS1 and miR-425-5p was verified via dual-luciferase reporter assay.

RESULTS

MSC-AS1 expression level was lowly expressed, while miR-425-5p level was highly in ovarian cancer tissues and cells. Elevation of MSC-AS1 has the ability to significantly inhibit cell proliferation and facilitate cell apoptosis in SKOV3 and A2780 cells. Moreover, MSC-AS1 targeted and negatively modulated miR-425-5p. MiR-425-5p up-regulation has been proved to partially reverse the tumor suppressive function of MSC-AS1 overexpression CONCLUSION: MSC-AS1 sponged miR-425-5p to inhibit the ovarian cancer progression. These findings may provide a promising therapeutic target for the treatment of ovarian cancer.

A Signature of Four Circulating microRNAs as Potential Biomarkers for Diagnosing Early-Stage Breast Cancer

Breast cancer (BC) is the most predominant type of cancer among women. The aim of this study is to find new biomarkers that can help in early detection of BC, especially for those who are too young to be screened using mammography as per guidelines. Using microRNA microarray, we previously showed dysregulation of 74 microRNAs in tumors from early BC patients as compared with normal adjacent tissues, which we were interested in studying in blood circulation. In this study, we investigated the expression of 12 microRNA (miR-21/miR-155/miR-23a/miR-130a/miR-145/miR-425-5p/miR-139-5p/miR-451/miR-195/miR-125b/miR-100, and miR-182) in the plasma of 41 newly diagnosed Lebanese BC patients with early invasive ductal carcinoma as compared with 32 healthy controls. Total RNA was extracted from plasma, and expression levels of miRNA of interest were measured using RT-qPCR followed by statistical analysis; miR-21, miR-155, miR-23a, miR-130a, miR-145, miR-425-5p, and miR-139-5p were significantly upregulated and miR-451 was significantly downregulated, in the plasma of BC patients as compared with healthy controls. The positively correlated miR-23a, miR-21, and miR-130a had a high diagnostic accuracy (86%). Importantly, the combination of miR-145/miR-425-5p/miR-139-5p/miR-130a scored the highest diagnostic accuracy of 95% with AUC = 0.97 (sensitivity 97% and specificity 91%). MicroRNAs are promising non-invasive diagnostic biomarkers for early-stage BC with the panel of miR-145/miR-425-5p/miR-139-5p/miR-130a having the highest diagnostic accuracy.

Analysis of ceRNA networks and identification of potential drug targets for drug-resistant leukemia cell K562/ADR

Background

Drug resistance is the main obstacle in the treatment of leukemia. As a member of the competitive endogenous RNA (ceRNA) mechanism, underlying roles of lncRNA are rarely reported in drug-resistant leukemia cells.

Methods

The gene expression profiles of lncRNAs and mRNAs in doxorubicin-resistant K562/ADR and sensitive K562 cells were established by RNA sequencing (RNA-seq). Expression of differentially expressed lncRNAs (DElncRNAs) and DEmRNAs was validated by qRT-PCR. The potential biological functions of DElncRNAs targets were identified by GO and KEGG pathway enrichment analyses, and the lncRNA-miRNA-mRNA ceRNA network was further constructed. K562/ADR cells were transfected with CCDC26 and LINC01515 siRNAs to detect the mRNA levels of GLRX5 and DICER1, respectively. The cell survival rate after transfection was detected by CCK-8 assay.

Results

The ceRNA network was composed of 409 lncRNA-miRNA pairs and 306 miRNA-mRNA pairs based on 67 DElncRNAs, 58 DEmiRNAs and 192 DEmRNAs. Knockdown of CCDC26 and LINC01515 increased the sensitivity of K562/ADR cells to doxorubicin and significantly reduced the half-maximal inhibitory concentration (IC₅₀) of doxorubicin. Furthermore, knockdown of GLRX5 and DICER1 increased the sensitivity of K562/ADR cells to doxorubicin and significantly reduced the IC₅₀ of doxorubicin.

Conclusions

The ceRNA regulatory networks may play important roles in drug resistance of leukemia cells. CCDC26/miR-140-5p/GLRX5 and LINC01515/miR-425-5p/DICER1 may be potential targets for drug resistance in K562/ADR cells. This study provides a promising strategy to overcome drug resistance and deepens the understanding of the ceRNA regulatory mechanism related to drug resistance in CML cells.

Small in Size, but Large in Action: microRNAs as Potential Modulators of PTEN in Breast and Lung Cancers

MicroRNAs (miRNAs) are well-known regulators of biological mechanisms with a small size of 19–24 nucleotides and a single-stranded structure. miRNA dysregulation occurs in cancer progression. miRNAs can function as tumor-suppressing or tumor-promoting factors in cancer via regulating molecular pathways. Breast and lung cancers are two malignant thoracic tumors in which the abnormal expression of miRNAs plays a significant role in their development. Phosphatase and tensin homolog (PTEN) is a tumor-suppressor factor that is capable of suppressing the growth, viability, and metastasis of cancer cells via downregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling. PTEN downregulation occurs in lung and breast cancers to promote PI3K/Akt expression, leading to uncontrolled proliferation, metastasis, and their resistance to chemotherapy and radiotherapy. miRNAs as upstream mediators of PTEN can dually induce/inhibit PTEN signaling in affecting the malignant behavior of lung and breast cancer cells. Furthermore, long non-coding RNAs and circular RNAs can regulate the miRNA/PTEN axis in lung and breast cancer cells. It seems that anti-tumor compounds such as baicalein, propofol, and curcumin can induce PTEN upregulation by affecting miRNAs in suppressing breast and lung cancer progression. These topics are discussed in the current review with a focus on molecular pathways.

miR-325-3p Promotes the Proliferation, Invasion, and EMT of Breast Cancer Cells by Directly Targeting S100A2

This study was designed to investigate the precise mechanisms of miR-325-3p/S100A2 axis in breast cancer (BC). In this study, we found that the level of miR-325-3p was dramatically increased in BC tissues and cell lines, and the expression of S100A2 was significantly decreased. Also, the high level of miR-325-3p was closely associated with low expression of S100A2 in BC tissues. Moreover, introduction of miR-325-3p significantly promoted proliferation, invasion, and EMT of BC cells. Bioinformatics analysis predicted that the S100A2 was a potential target gene of miR-325-3p. Luciferase reporter assay demonstrated that miR-325-3p could directly target S100A2. In addition, miR-325-3p overexpression had similar effects with knockdown of S100A2 on BC cells. Overexpression of S100A2 in BC cells partially reversed the promoted effects of miR-325-3p mimic. Overexpression of miR-325-3p promoted cell proliferation, invasion, and EMT of BC cells by directly downregulating S100A2 expression.

MicroRNA-623 inhibits tumor progression and is a predictor of poor prognosis of breast cancer

Dysregulated microRNAs (miRNAs) serve vital roles in the progression and prognosis of breast cancer. miR-623 has been reported to influence the progression of numerous other cancers, such as lung adenocarcinoma and hepatocellular carcinoma, however, its role in breast cancer remains unclear. In the present study, the mRNA expression of miR-623 was studied in 121 pairs of breast cancer and adjacent normal tissues and cultured cell lines by reverse-transcription quantitative PCR. The association between miR-623 expression and clinical characteristics or the overall survival rate of patients was investigated by the χ² test or Cox regression analysis, respectively. The role of miR-623 in cell proliferation, migration and invasion of breast cancer cells was evaluated by cell transfection to regulate miR-623 expression and the CCK8 and Transwell assays, respectively. miR-623 was downregulated in breast cancer tissues and cell lines compared with normal tissues and breast epithelial cell lines. The χ² test demonstrated that the downregulation of miR-623 was associated with the tumor node metastasis (TNM) stage of patients with breast cancer. miR-623 and TNM stage were considered as two independent prognostic factors for breast cancer. Additionally, cell proliferation, migration, and invasion of breast cancer cells were promoted by the downregulation of miR-623, while upregulation of miR-623 led to inhibition of the aforementioned processes. Downregulation of miR-623 in breast cancer is associated with the development of breast cancer and indicates a poor prognosis of patients. The downregulation of miR-623 promotes cell proliferation, migration and invasion of breast cancer. The findings of the present study indicate that miR-623 functions as a prognosis biomarker and a tumor suppressor in breast cancer, which provides a potential therapeutic target for patients with breast cancer.

Xiaotan Jieyu Prescription Alleviates Breast Precancerous Lesions through PI3K/Akt Signaling Pathway

Methods

The successfully established breast precancerous lesion rat model and normal healthy rats were randomly assigned into the blank (BLA), model (MOD), XTJY-low (LD), XTJY-medium (MD), XTJY-high (HD), and tamoxifen (TAM) groups. Different concentrations of XTJY and saline were supplied by intragastric administration for 4 consecutive weeks to assess the protective effect of XTJY on the progress of the breast precancerous lesion in rats involving the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway.

Results

In this study, it determined that 10 mg/each rat DMBA-combined estrogen and progesterone induction for 10 weeks was the optimal condition for the establishment of the breast precancerous lesion rat model. In vivo administration of XTJY or TAM was found to inhibit the development of the breast precancerous lesion, and the occurrence rate of breast invasive carcinomas was decreased by about 50%. Furthermore, XTJY or TAM markedly reduced protein expressions of PI3K and p-Akt and increased protein expressions of PTEN.

Conclusion

These data indicated that XTJY can significantly alleviate the development of breast precancerous lesions by inhibiting the activation of the PI3K/Akt signaling pathway. XTJY may be a promising drug for the treatment of precancerous lesions in breast cancer.

MiR-3194-3p Inhibits Breast Cancer Progression by Targeting Aquaporin1

Increasing evidence indicates that the Aquaporin1 (AQP1) aberrant expression may be related to a wide variety of human cancers, including breast cancer (BC). In the present study, we explore the effects and possible mechanism of miR-3194-3p on the biological behaviors of BC. At first, miR-3194-3p is found to modulate AQP1 expression targeting the 3′-UTR using miRNA target prediction algorithms. MiR-3194-3p expression is markedly downregulated, and AQP1 expression is upregulated in BC tissues compared with adjacent normal breast tissues. Moreover, the differential expression of miR-3194-3p and AQP1 are observed in four BC cells with different malignancy degree. Meanwhile, a significant negative correlation between AQP1 and miR-3194-3p expressions in tumor tissues from 30 BC patients is revealed. miR-3194-3p mimic remarkably inhibits cell proliferation, migration, and invasion as well as promotes apoptosis in MDA-MB-231 cells while miR-3194-3p inhibitors exert an opposite role in MCF-7 cells. Dual-luciferase reporter system demonstrates that AQP1 is a direct target gene of miR-3194-3p. Overexpression of AQP1 by pBABE-puro-AQP1 vector partially abrogates the effect of miR-3194-3p mimic in MDA-MB-231 cells. In short, our results suggest that miR-3194-3p suppresses BC cell proliferation, migration, and invasion by targeting AQP1, providing a novel insight into BC tumorigenesis and treatment.

LncRNA TTN-AS1 Regulates miR-524-5p and RRM2 to Promote Breast Cancer Progression

Background

Recent studies suggest many long non-coding RNAs (lncRNAs) are crucial oncogenes or tumor suppressors. This study intended to investigate the biological function and mechanism of lncRNA TTN antisense RNA 1 (TTN-AS1) in the progression of breast cancer (BC).

Materials and Methods

BC tissue samples were collected. The expression of TTN-AS1 in BC tissues and adjacent tissues was detected by qRT-PCR, and the relationship between pathological indicators and TTN-AS1 expression was analyzed by chi-square test. BC cell lines T47D and BT549 were utilized as cell models. CCK-8 assay and BrdU assay were used to detect the effect of TTN-AS1 on BC cell proliferation. Transwell assay was used to detect the effects of TTN-AS1 on cell migration and invasion. In addition, dual-luciferase reporter gene assay was used to confirm the targeting relationship between miR-524-5p and TTN-AS1. Western blot was used to detect the function of TTN-AS1 on regulating ribonucleotide reductase subunit 2 (RRM2) and survivin. Additionally, subcutaneous xenotransplanted tumor model and tail vein injection model were constructed in vivo.

Results

The expression of TTN-AS1 in BC tissues was significantly higher than that in normal tissues, and its high expression was correlated with adverse pathological indicators. Overexpression of TTN-AS1 significantly promoted the proliferation, migration and invasion of BC cells. TTN-AS1 knockdown suppressed the malignant phenotypes of BC cells. TTN-AS1 overexpression significantly impeded the expression of miR-524-5p, but increased the expression of RRM2.

Conclusion

TTN-AS1 exerts oncogenic function in BC by repressing miR-524-5p and increasing the expression of RRM2.