Suppression of cell migration is promoted by miR-944 through targeting of SIAH1 and PTP4A1 in breast cancer cells

The role of miR-133a in silibinin-mediated inhibition of the PI3K/AKT/mTOR pathway in MCF-7 breast carcinoma cells

Breast cancer is particularly severe in women. Research highlights the crucial role of miRNAs in key cellular processes, showcasing their intricate interactions with the oncogenic PI3K/AKT/mTOR (PAM) signaling pathway and underscoring their significant role as tumor suppressors. The effect of silibinin on cell growth and survival was evaluated using an MTT assay. Bioinformatics analysis identified putative miR-133a targets inside the PAM pathway. After incubating MCF-7 cells with silibinin, we measured miR-133a, EGFR, PI3K, AKT, PTEN, and mTOR expression levels using qRT-PCR. Furthermore, protein expression levels of mTOR were assessed using Western blotting. The MTT experiment displayed that silibinin effectively inhibits MCF-7 cell proliferation in a time- and dose-dependent manner. Silibinin's IC50 value, determined at 370 μM after 48 hours, was established. qRT-PCR analysis at this IC50 concentration highlighted reduced expression of EGFR, PI3K, AKT, PTEN, and mTOR mRNAs, alongside increased miR-133a expression. Notably, miR-133a exhibited a negative correlation with both EGFR and PIK3C2A expression. Furthermore, western blotting confirmed silibinin's capacity to diminish p-mTOR protein levels, the ultimate element of the PAM signaling pathway. The findings enhance comprehension of silibinin's impact on PAM signaling and miR-133a expression, offering promise for targeted therapies in disrupting oncogenic pathways in MCF-7 breast cancer cells. This insight could advance breast cancer treatment strategies.

microRNA-944 inhibits breast cancer cell proliferation and promotes cell apoptosis by reducing SPP1 through inactivating the PI3K/Akt pathway

Breast cancer is a common malignancy in women with poor prognosis. This study aimed to investigate the molecular mechanism of microRNA-944 (miR-944) mediated secreted phosphoprotein-1 (SPP1) in breast cancer progression and its regulatory effect on the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Differential gene analysis was performed to identify key genes associated with breast cancer development by screening breast cancer-related microarray data. The expression of miR-944 and SPP1 and their relationship were determined in clinical samples and cells. sh-SPP1, oe-SPP1, LY294002 or miR-944 mimic were transfected into MCF-7 cells to investigate the role of miR-944 mediated SPP1 in breast cancer development and its regulatory effect on the PI3K/Akt pathway. Finally, the tumorigenicity of breast cancer cells was observed in nude mice. Through bioinformatics analysis, we identified SPP1 as a key gene in breast cancer, and miR-944 as an upstream miRNA of SPP1. In breast cancer tissues and cells, the expression of miR-944 was decreased while that of SPP1 was increased. miR-944 negatively regulated the expression of SPP1. In breast cancer cells, SPP1 activated the PI3K/Akt pathway to promote cell proliferation and inhibit apoptosis. In vitro cell experiments showed that the downregulation of miR-944 promoted the high expression of SPP1, which then activated the PI3K/Akt signaling pathway, promoting breast cancer cell proliferation. In vivo experiments further confirmed the anti-cancer role of miR-944 mediated SPP1 in breast cancer. Our study highlights the role of miR-944 mediated SPP1 in inhibiting breast cancer progression by blocking the PI3K/Akt pathway.

Emerging roles of circ_NRIP1 in tumor development and cancer therapy (Review)

Circular RNA (circRNA) is a class of endogenous non-coding RNA, a type of single-stranded covalently closed RNA molecule formed by alternative splicing of exons or introns. Previous studies have demonstrated that circRNA participates in modulating biological processes such as cell proliferation, differentiation and apoptosis, and plays key roles in tumor occurrence and development. CircRNA nuclear receptor interacting protein 1 (circ_NRIP1), a form of circRNA, is abnormally expressed in certain human tumor types. It is present at a higher abundance compared with cognate linear transcripts and can regulate malignant biological behaviors such as tumor proliferation, invasion and migration, revealing a currently unexplored frontier in cancer progression. The present review presents a pattern of circ_NRIP1 expression in various malignant tumor types and highlights its significance in cancer development, in addition to its potential as a disease indicator or future therapeutic agent.

Investigation of miR-133a, miR-637 and miR-944 genes expression and their relationship with PI3K/AKT signaling in women with breast cancer

PURPOSE

MicroRNAs (miRNAs) are regulatory molecules capable of positively or negatively regulating signaling pathways, and are involved in tumorigenesis as well as various aspects of cancer. The purpose of this study was to investigate the expression levels of miR-133a, miR-637, and miR-944 in serum and tumor tissues as well as their relationship with the expression level of phosphatidylinositol-3-kinase (PI3K) and protein kinase-B (AKT) genes and proteins along with their clinical significance in breast cancer.

METHODS

The expressions of miR-133a, miR-637, miR-944, PI3K, and AKT genes were examined in the tumor and tumor margin tissues of 40 patients with breast cancer, as well as the serum levels of miR-133a, miR-637, and miR-944 in these patients and 40 healthy groups by quantitative real-time PCR (qRT-PCR). PI3K and AKT proteins expression in tumor and tumor margin tissues were detected using immunohistochemistry (IHC).

RESULTS

The expression levels of miR-133a and miR-637 in the tumor tissue and serum of patients were lower than those in the tumor margin tissue and serum of the healthy group, respectively. In addition, the expression level of miR-944 in the tumor tissue was lower than that in the tumor margin tissue, but its expression increased in the serum of cancer patients compared to that in the healthy group. The expression of miR-637 was correlated with tumor location and Her2 receptors, and the expression of miR-944 was correlated with tumor location and family history. PI3K and AKT mRNA and protein levels were higher in the tumor tissues than in the tumor margin tissues (p < 0.05).

CONCLUSION

The results of our study revealed that miR-637 has a better diagnostic value in breast cancer than miR-133a and miR-944.

Upregulation of circ_0008812 and circ_0001583 predicts poor prognosis and promotes breast cancer proliferation

Background: Accumulating evidence suggests that circular RNAs (circRNAs) are highly correlated with tumor progression and pathogenesis in breast cancer. Whereas, their regulatory roles and corresponding mechanisms in breast cancer are still not exhaustive. Thus, we intended to establish circRNA-mediated competive endogenous RNA (ceRNA) network to uncover the possible roles and clinical implications of circRNAs in breast cancer.

Methods: Microarray and RNA-sequencing (RNA-seq) data were download from GEO and TCGA database to screen for differentially expressed RNAs (DEcircRNAs, DEmiRNAs, DEmRNAs) in breast cancer. By implementing online databases, we established ceRNA networks, performed gene set enrichment analysis, constructed protein-protein interaction (PPI) networks, and assessed the expression levels and prognostic significance of hub genes. Subsequently, we explored the functions of prognosis-related genes and constructed gene-drug interaction networks. Finally, the functional roles of DEcircRNAs in breast cancer were revealed via MTT and colony formation assay.

Results: Based on the identified 8 DEcircRNAs, 25 miRNAs and 216 mRNAs, a ceRNA regulatory network was established. Further analysis revealed that prominent enrichments were transcription factor binding, transforming growth factor-beta (TGF-β) and Apelin signaling pathway etc. PPI network and survival curves analysis showed that elevated levels of hub genes (RACGAP1 and KPNA2) were associated with poorer prognosis. They were found to be positively relevant to cell cycle and proliferation. Then a prognostic sub-network of ceRNA was constructed, consisting of 2 circRNAs, 4 miRNAs and 2 mRNAs. The gene-drug interaction network showed that numerous drugs could regulate the expression of these two prognosis-related genes. Functional experiments showed that depletion of circ_0008812 and circ_0001583 could significantly inhibit the proliferation of MCF-7 cells.

Conclusion: Our study constructed 4 prognostic regulatory axes that are significantly correlated with tumor prognosis in breast cancer patients, and uncover the roles of circ_0008812 and circ_0001583 in breast cancer, providing a new perspective into the molecular mechanisms of breast cancer pathogenesis.

Novel Insights into miR-944 in Cancer

Simple Summary

miR-944 is localized in intron 4 of TP63. ΔNp63 in intron 3 of TP63 recruits the transcription factor AP-2 to promote miR-944 gene expression, which mediates epidermal differentiation induction by ΔNp63. miR-944 is dysregulated in various cancers. In squamous cell carcinoma. miR-944 can target and inhibit 27 protein-coding genes, thereby regulating cell cycle, proliferation, apoptosis, epithelial mesenchymal transition, cancer cell invasion and migration, and other cell behaviors. The genes targeted by miR-944 are involved in three signaling pathways, including the Wnt/β-catenin pathway, Jak/STAT3 pathway, and PI3K/AKT pathway. miR-944 was regulated by a total of 11 competing endogenous RNAs, including 6 circular RNAs and 5 long non-coding RNAs. Abnormally expressed miR-944 can act as an independent prognostic factor and is closely related to tumor invasion, lymph node metastasis, TNM staging, and drug resistance. miR-944 is expected to become a critical biomarker with great clinical application value in cancer.

Abstract

miRNA is a class of endogenous short-chain non-coding RNAs consisting of about 22 nucleotides. miR-944 is located in the fourth intron of the TP63 gene in the 3q28 region. miR-944 is abnormally expressed in cancers in multiple systems including neural, endocrine, respiratory, reproductive, and digestive systems. miR-944 can target at least 27 protein-coding genes. miR-944 can regulate a series of cell behaviors, such as cell cycle, proliferation, invasion and migration, EMT, apoptosis, etc. miR-944 participates in the networks of 11 ceRNAs, including six circRNAs and five lncRNAs. miR-944 is involved in three signaling pathways. The abnormal expression of miR-944 is closely related to the clinicopathological conditions of various cancer patients. Deregulated expression of miR-944 is significantly associated with clinicopathology and prognosis in cancer patients. In addition, miR-944 is also associated with the development of DDP, RAPA, DOX, and PTX resistance in cancer cells. miR-944 is involved in the anticancer molecular mechanisms of matrine and Rhenium-liposome drugs. In conclusion, this work systematically summarizes the related findings of miR-944, which will provide potential hints for follow-up research on miR-944.

Inhibitory Effect of miR-339-5p on Glioma through PTP4A1/HMGB1 Pathway

Objective

Finding miR-339-5p inhibitory functions in glioma through PTP4A1/HMGB1 pathway.

Methods

From May 2020 to August 2021, 20 glioblastoma and para cancer tissues were chosen for qRT-PCR analysis. The miR-NC, miR-con, miR-339-5PMIMIC, and miR-con + groups were transfected into human glioma U251 cells. The capacity of cell vascular-like structure construction was found by simulating angiogenesis, and the ability of cell movement was examined by cell scratching. The twofold luciferase reporter gene method determined that miR-339-5p targets PTP4A1, and the protein expression levels of PTP4A1 and HMGB1 were examined using Western blot.

Results

MiR-339-5P expression was substantially lower in cancer samples than noncancer samples (P < 0.05). PTP4A1 expression in cancer samples was higher than in healthy controls (P < 0.05). The miR-339-5p group produced significantly less vascular-like structures than the NC and miR-con groups (P < 0.05). The miR-339-5p group lowered the invasive index and migratory rate of U251 cells (P < 0.05). PTP4A1 inhibited the luciferase activity of the pTP4A1-WT reporter gene (P < 0.05) but not the PTP4A1-MUT (P > 0.05). The miR-339-5p group had lower protein levels of PTP4A1 and HMGB1 than the NC and miR-con groups (P < 0.05). The development of vascular-like structures was substantially more significant in the miR-con +PTP4A1 group than in the miR-con and miR-339-5p +PTP4A1 groups (P < 0.05). In terms of migration and invasion index, there was a substantial difference between the miR-339-5p +PTP4A1 and the miR-con +PTP4A1 groups (P < 0.05). The miR-con +PTP4A1 group had a greater migration rate and invasive index than the miR-con and miR-339-5p +PTP4A1 groups (P < 0.05).

Conclusion

MiR-339-5P inhibits angiogenic mimicry, migration, and invasion of brain glioma U251 cells by inhibiting the PTP4A1/HMGB1 signal pathway.

RP5-1148A21.3 (lncRP5) exerts oncogenic function in human ovarian carcinoma

Ovarian cancer (OC) is a fatal gynecological malignancy that is difficult to diagnose at early stages. Various long non-coding RNAs (lncRNAs) are aberrantly expressed in OC and exert regulatory effects on OC; however, the underlying mechanism requires in-depth investigation. This work is designed to explore the molecular regulatory axis of a newly identified lncRNA in OC, that is, lncRNA RP5-1148A21.3 (lncRP5). RT-qPCR shows lncRP5 is significantly upregulated in OC patients and cell lines, and it is mainly located in the cytoplasm of OC cells. The results of CCK-8, colony formation, and transwell assays demonstrate that overexpression of lncRP5 greatly contributes to malignant behaviors of OC cells, while inhibition of lncRP5 shows the opposite effects. Moreover, the binding relationship between lncRP5 and miR-545-5p is predicted by bioinformatics and is further verified by luciferase assay. Functionally, the regulatory effects of lncRP5 and miR-545-3p are negatively related; miR-545-5p serves as a tumor suppressor in OC. Further studies demonstrate that PTP4A1 is the target gene of miR-545-5p. Overexpression of PTP4A1 abrogates the inhibitory function of miR-545-5p on OC cell growth and metastasis. The lncRP5/miR-545-5p/PTP4A1 axis is subsequently demonstrated in vivo, and knockdown of lncRP5 notably inhibits tumor growth. This study provides a novel regulatory mechanism of OC, which may contribute to the diagnosis and therapy of OC.

Siah1 in cancer and nervous system diseases (Review)

The dysregulation of the ubiquitin‑proteasome system will result in the abnormal accumulation and dysfunction of proteins, thus leading to severe diseases. Seven in absentia homolog 1 (Siah1), an E3 ubiquitin ligase, has attracted wide attention due to its varied functions in physiological and pathological conditions, and the numerous newly discovered Siah1 substrates. In cancer and nervous system diseases, the functions of Siah1 as a promoter or a suppressor of diseases are related to the change in cellular microenvironment and subcellular localization. At the same time, complex upstream regulations make Siah1 different from other E3 ubiquitin ligases. Understanding the molecular mechanism of Siah1 will help the study of various signaling pathways and benefit the therapeutic strategy of human diseases (e.g., cancer and nervous system diseases). In the present review, the functions and regulations of Siah1 are described. Moreover, novel substrates of Siah1 discovered in recent studies will be highlighted in cancer and nervous system diseases, providing ideas for future research and clinical targeted therapies using Siah1.

Analysis and validation of m6A regulatory network: a novel circBACH2/has-miR-944/HNRNPC axis in breast cancer progression

Background

N6-methyladenosine (m6A), the most abundant and reversible modification of mRNAs in eukaryotes, plays pivotal role in breast cancer (BC) tumorigenesis and progression. Circular RNAs (circRNAs) can act as tumor promoters or suppressors by microRNA (miRNA) sponges in BC. However, the underlying mechanism of circRNAs in BC progression via regulating m6A modulators remains unclear.

Methods

Prognostic m6A RNA methylation regulators were identified in 1065 BC patients from The Cancer Genome Atlas (TCGA) project. Differentially expressed (DE) miRNAs and DE circRNAs were identified between BC and normal samples in TCGA and GSE101123, respectively. MiRNA-mRNA interactive pairs and circRNA-miRNA interactive pairs were verified by MiRDIP and Circular RNA Interactome. GSEA, KEGG, and ssGSEA were executed to explore the potential biological and immune functions between HNRNPC-high and HNRNPC-low expression groups. qRT-PCR and Western blot were used to quantify the expression of HNRNPC and circBACH2 in MCF-7 and MDA-MB-231 cells. The proliferation of BC cells was assessed by CCK-8 and EdU assay.

Results

2 m6A RNA methylation regulators with prognostic value, including HNRNPC and YTHDF3, were identified in BC patients. Then, the regulatory network of circRNA-miRNA-m6A modulators was constructed, which consisted of 2 DE m6A modulators (HNRNPC and YTHDF3), 12 DE miRNAs, and 11 DE circRNAs. Notably, BC patients with high expression of HNRNPC and low expression of hsa-miR-944 were correlated with late clinical stages and shorter survival times. Besides, the results from the KEGG inferred that the DE HNRNPC was associated with the MAPK signaling pathway in BC. Moreover, the circBACH2 (hsa_circ_0001625) was confirmed to act as hsa-miR-944 sponge to stimulate HNRNPC expression to promote BC cell proliferation via MAPK signaling pathway, thus constructing a circBACH2/hsa-miR-944/HNRNPC axis in BC.

Conclusions

Our findings decipher a novel circRNA-based m6A regulatory mechanism involved in BC progression, thus providing attractive diagnostic and therapeutic strategies for combating BC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03196-4.

PRNCR1: a long non-coding RNA with a pivotal oncogenic role in cancer

Long non-coding RNAs (lncRNAs) have been gaining importance in the field of cancer research in recent years. PRNCR1 (prostate cancer-associated non-coding RNA1) is a 12.7 kb, intron-less lncRNA found to play an oncogenic role in malignancy of diverse organs including prostate, breast, lung, oral cavity, colon and rectum. Single-nucleotide polymorphisms (SNPs) of PRNCR1 locus have been found to be associated with cancer susceptibility in different populations. In this review, an attempt has been made for the first time to summarize all sorts of available data on PRNCR1 to date from relevant databases (GeneCard, LncExpDB, Ensembl genome browser, and PubMed). As functional roles of PRNCR1, miRNA (microRNA) sponging was mostly highlighted in the pathogenesis of different cancer; in addition, an association of the lncRNA with chromatin-modifying complex to enhance androgen receptor-mediated gene transcription was reported in prostate cancer. Diagnostic and prognostic importance of PRNCR1 was found in some malignancies suggesting potency of the lncRNA to serve as a clinical biomarker. For PRNCR1 SNPs, although cancer susceptibility of the risk alleles/genotypes was reported in different populations, majorities of the findings were not replicated and underlying molecular mechanisms remained unexplored. Therapeutic implication of PRNCR1 was not studied well and future research may come up in this direction for intervening novel strategies to fight against cancer.

The role of noncoding RNAs in pituitary adenoma

Pituitary adenomas (PAs) are common cranial tumors that affect the quality of life in patients. Early detection of PA is beneficial for avoiding clinical complications of this disease and increasing the quality of life. Noncoding RNAs, including long noncoding RNA, miRNA and circRNA, regulate protein expression, mostly by inhibiting the translation process. Studies have shown that dysregulation of noncoding RNAs is associated with PA. Hence understanding the expression pattern of noncoding RNAs can be considered a promising method for developing biomarkers. This article reviews data on the expression pattern of dysregulated noncoding RNAs involved in PA. Possible molecular mechanisms by which the dysregulated noncoding RNA could possibly induce PA are also described.

Bioinformatics analysis for the identification of key genes and long non-coding RNAs related to bone metastasis in breast cancer

The molecular mechanism of bone metastasis in breast cancer is largely unknown. Herein, we aimed to identify the key genes and long non-coding RNAs (lncRNAs) related to the bone metastasis of breast cancer using a bioinformatics approach. We screened differentially expressed genes and lncRNAs between normal breast and breast cancer bone metastasis samples using the GSE66206 dataset from the Gene Expression Omnibus. We also constructed a differentially expressed lncRNA-mRNA interaction network and analyzed the node degrees to identify the driving genes. After finding potential pathogenic modules of breast cancer bone metastasis, we identified breast cancer bone metastasis-related modules and functional enrichment analysis of the genes and lncRNAs in the modules. Based on the above analysis, we constructed a differentially expressed lncRNA-mRNA network related to bone metastasis in breast cancer and identified core driver genes, including BNIP3 and the lncRNA RP11-317-J19.1. The role of core driver genes and lncRNAs in the network implies their biological functions in regulating bone development and remodeling. Thus, targeting the core driver genes and lncRNAs in the network may be a promising therapeutic strategy to manage bone metastasis.

Systems Biomedicine of Primary and Metastatic Colorectal Cancer Reveals Potential Therapeutic Targets

Colorectal cancer (CRC) is one of the major causes of cancer deaths across the world. Patients' survival at time of diagnosis depends mainly on stage of the tumor. Therefore, understanding the molecular mechanisms from low-grade to high-grade stages of cancer that lead to cellular migration from one tissue/organ to another tissue/organ is essential for implementing therapeutic approaches. To this end, we performed a unique meta-analysis flowchart by identifying differentially expressed genes (DEGs) between normal, primary (primary sites), and metastatic samples (Colorectal metastatic lesions in liver and lung) in some Test datasets. DEGs were employed to construct a protein-protein interaction (PPI) network. A smaller network containing 39 DEGs was then extracted from the PPI network whose nodes expression induction or suppression alone or in combination with each other would inhibit tumor progression or metastasis. These DEGs were then verified by gene expression profiling, survival analysis, and multiple Validation datasets. We suggested for the first time that downregulation of mitochondrial genes, including ETHE1, SQOR, TST, and GPX3, would help colorectal cancer cells to produce more energy under hypoxic conditions through mechanisms that are different from "Warburg Effect". Augmentation of given antioxidants and repression of P4HA1 and COL1A2 genes could be a choice of CRC treatment. Moreover, promoting active GSK-3β together with expression control of EIF2B would prevent EMT. We also proposed that OAS1 expression enhancement can induce the anti-cancer effects of interferon-gamma, while suppression of CTSH hinders formation of focal adhesions. ATF5 expression suppression sensitizes cancer cells to anchorage-dependent death signals, while LGALS4 induction recovers cell-cell junctions. These inhibitions and inductions would be another combinatory mechanism that inhibits EMT and cell migration. Furthermore, expression inhibition of TMPO, TOP2A, RFC3, GINS1, and CKS2 genes could prevent tumor growth. Besides, TRIB3 suppression would be a promising target for anti-angiogenic therapy. SORD is a poorly studied enzyme in cancer, found to be upregulated in CRC. Finally, TMEM131 and DARS genes were identified in this study whose roles have never been interrogated in any kind of cancer, neither as a biomarker nor curative target. All the mentioned mechanisms must be further validated by experimental wet-lab techniques.

miR-944 Suppresses EGF-Induced EMT in Colorectal Cancer Cells by Directly Targeting GATA6

Background

miR-944 belongs to the MicroRNAs family, as shown in our previous study, and is essential in the colorectal cancer (CRC) progression. It is negatively associated with invasion depth and lymph node status. Epithelial-mesenchymal transition (EMT) is essential in tumor invasion and metastasis. However, the relationship between miR-944 and EMT in CRC is unknown and should be further investigated.

Methods

Epithelial–mesenchymal transition (EMT) progression in CRC cell lines was detected with Cell morphology and Western blotting. CRC cell migration and invasion were examined using Transwell assays. Transcriptome and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. The potential pathway of miR-944 and GATA6 were predicted using KEGG analysis. Colocalization was validated using immunofluorescence and Immunohistochemistry. Nuclear and Cytoplasmic Protein Extraction assays were conducted to determine the effects of miR-944 on Wnt/β-catenin signaling.

Results

We found that miR‑944 influences EGF-induced EMT malignant phenotype in vitro. KEGG analyses showed that miR-944 and GATA6 are associated with EMT related pathways, wnt signaling pathways. On the other hand, Western Blot analyses showed that miR-944 can regulate EMT and wnt-β-catenin pathway-related protein, including β-catenin, ZEB1, snail1 via GATA6 regulation. miR-944 also abrogates E-ca after EGF induction. Immunohistochemistry (IHC) and Immunofluorescence (IF) co-expression showed that GATA6 expression is positively associated with β-catenin and ZEB1. GATA6 silencing can reverse EMT malignant phenotype and alterations of related protein induced by miR-944. Quantitative polymerase chain reaction analysis results showed that miR-944 is negatively associated with the UICC stage (P= 0.02), lymph nodes (p=0.04), and liver metastasis (p=0.03). Moreover, patients with high miR-944 expression have better survival (p=0.045). We finally combined miR-944 and GATA6 and found that miR-944/GATA6 ratio could be a novel prognostic biomarker in the TCGA dataset and it is an independent risk prognosis factor (p=0.045).

Conclusion

Our results suggest that miR-944 suppresses the aggressive biological processes by directly repressing GATA6 expression and could be a potential candidate for therapeutic applications in CRC.

NCAPG upregulation mediated by four microRNAs combined with activation of the p53 signaling pathway is a predictor of poor prognosis in patients with breast cancer

The role of non-SMC condensin I complex subunit G (NCAPG) in breast cancer remains unclear. The present study used online databases, reverse transcription-quantitative PCR, flow cytometry and western blotting to determine the expression levels, prognosis and potential molecular mechanisms underlying the role of NCAPG in breast cancer. The association between NCAPG expression and several different clinicopathological parameters in patients with breast cancer was determined, and the results revealed that NCAPG expression was negatively associated with estrogen receptor and progesterone receptor positive status, but was positively associated with HER2 positive status, Nottingham Prognostic Index score and Scarff-Bloom-Richardson grade status. Furthermore, upregulated expression levels of NCAPG resulted in a poor prognosis in patients with breast cancer. A total of 27 microRNAs (miRNAs/miRs) were predicted to target NCAPG, among which four miRNAs (miR-101-3p, miR-195-5p, miR-214-3p and miR-944) were predicted to most likely regulate NCAPG expression in breast cancer. A total of 261 co-expressed genes of NCAPG were identified, including cell division cyclin 25 homolog C (CDC25C), and pathway enrichment analysis indicated that these co-expressed genes were significantly enriched in the p53 signaling pathway. CDC25C expression was downregulated in breast cancer and was associated with a poor prognosis. These findings suggested that upregulated NCAPG expression may be a prognostic biomarker of breast cancer.

Long Noncoding RNA FGD5-AS1 Knockdown Decrease Viability, Migration, and Invasion of Non-Small Cell Lung Cancer (NSCLC) Cells by Regulating the MicroRNA-944/MACC1 Axis

Objective:

Long noncoding RNA FGD5 antisense RNA 1 (FGD5-AS1) participates in the regulation of non-small cell lung cancer (NSCLC) progression, but the underlying mechanisms are not fully revealed. This study aimed to determine the regulatory mechanism of FGD5-AS1 on the viability, migration, and invasion of NSCLC cells.

Methods:

QRT-PCR was performed to measure the expression of FGD5-AS1, microRNA-944 (miR-944), and MACC1 in NSCLC. The correlation between FGD5-AS1 and clinicopathological features of NSCLC patients was analyzed. The viability of NSCLC cells were detected using MTT assay, and the migration and invasion were measured by transwell assay. Additionally, dual-luciferase reporter assay was used to demonstrate the interactions among FGD5-AS1, miR-944, and MACC1. Furthermore, exosomes were isolated from NSCLC cells and identified by transmission electron microscopy (TEM) and western blot. Then, the macrophages treated with exosomes were co-cultured with NSCLC cells to assess the effect of exosomes containing lower FGD5-AS1 level on NSCLC.

Results:

The expression of FGD5-AS1 and MACC1 was increased in NSCLC, but miR-944 expression was decreased. FGD5-AS1 expression had significantly correlation with TNM stage and metastasis in NSCLC patients. FGD5-AS1 knockdown decreased the viability, migration, and invasion of NSCLC cells. Additionally, FGD5-AS1 and MACC1 were both targeted by miR-944 with the complementary binding sites at 3’ UTR. In the feedback experiments, miR-944 inhibition or MACC1 overexpression reversed the reduction effect of FGD5-AS1 knockdown on the tumorigenesis of NSCLC. Moreover, silencing of FGD5-AS1 suppressed macrophages M2 polarization, and eliminated the promoting effects of exosomes mediated macrophages on NSCLC cell migration and invasion.

Conclusions:

FGD5-AS1 knockdown attenuated viability, migration, and invasion of NSCLC cells by regulating the miR-944/MACC1 axis, providing a new therapeutic target for NSCLC.

LncRNA SNHG6 Induces Epithelial-Mesenchymal Transition of Pituitary Adenoma Via Suppressing MiR-944

Background:

Pituitary adenoma (PA) is a common primary brain tumor with invasive properties. Despite that long noncoding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) exerts oncogenic function in cancer cells and that miR-944 inhibits epithelial–mesenchymal transition (EMT) of cancer cells are well documented, few studies have explored the function and mechanism of SNHG6 and miR-944 in invasive pituitary adenoma (IPA).

Materials and Methods:

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of SNHG6 and miR-944 in PA samples. Human PA cell line HP75 was used as a cell model. The biological effects of SNHG6 and miR-944 on HP75 cells were investigated with cell counting kit-8 (CCK-8) assay, Transwell assay, and scratch healing assay in vitro, respectively. Markers of EMT, including E-cadherin and vimentin, were detected by Western blot. Interactions between SNHG6 and miR-944, miR-944 and RAB11A were determined by bioinformatics analysis, qRT-PCR, and dual luciferase reporter assay.

Results:

SNHG6 was significantly upregulated in IPA samples, whereas miR-944 was downregulated. SNHG6 markedly promoted viability, migration, invasion, and EMT of PA cells, whereas miR-944 transfection had the opposite effects. SNHG6 could downregulate miR-944, and there was a negative correlation between SNHG6 expression and miR-944 expression in IPA samples. Besides, it was confirmed that miR-944 could pair with the 3′-untranslated region of RAB11A and repress its expression.

Conclusions:

This study authenticates that the SNHG6/miR-994/RAB11A axis plays a crucial role in regulating proliferation, migration, invasion, and EMT of IPA cells. SNHG6 and miR-994 can serve as novel valuable therapeutic targets for IPA.

Synergetic Effects of Intronic Mature miR-944 and ΔNp63 Isoforms on Tumorigenesis in a Cervical Cancer Cell Line

miR-944 is located in an intron of the tumor protein p63 gene (TP63). miR-944 expression levels in cervical cancer tissues are significantly higher than in normal tissues and are associated with tumor size, International Federation of Gynecology and Obstetrics (FIGO) stage, lymph node metastasis, and survival. However, associations of miR-944 with its host gene, TP63, which encodes TAp63 and ΔNp63, in cervical cancer have not been fully investigated. A positive correlation between miR-944 and ΔNp63 mRNA expression was identified in cervical cancer tissues. Furthermore, when the expression of miR-944 and ΔNp63 was simultaneously inhibited, cell proliferation-, differentiation- epithelial-mesenchymal transition (EMT)-, transcription-, and virus-associated gene clusters were shown to be significantly more active according to functional annotation analysis. Cell viability and migration were more reduced upon simultaneous inhibition with anti-miR-944 or ΔNp63 siRNA than with inhibition with anti-miR-944 or ΔNp63 siRNA alone, or scramble. In addition, Western blot analysis showed that the simultaneous inhibition of miR-944 and ΔNp63 reduced EMT by increasing the expression of epithelial markers such as claudin and by decreasing mesenchymal markers such as N-cadherin and vimentin. Slug, an EMT transcription factor, was also decreased by the simultaneous inhibition of miR-944 and ΔNp63. Thus, associations between miR-944 and ΔNp63 in cervical cancer could help to elucidate the function of this intronic microRNA and its role in carcinogenesis.

Host cell factors stimulate HIV-1 transcription by antagonizing substrate-binding function of Siah1 ubiquitin ligase to stabilize transcription elongation factor ELL2

The Siah1 and Siah2 ubiquitin ligases are implicated in diverse biological processes ranging from cellular stress responses, signaling to transcriptional regulation. A key substrate of Siah1 is ELL2, which undergoes proteolysis upon polyubiquitination. ELL2 stimulates transcriptional elongation and is a subunit of the Super Elongation Complex (SEC) essential for HIV-1 transactivation. Previously, multiple transcriptional and post-translational mechanisms are reported to control Siah's expression and activity. Here we show that the activity of Siah1/2 can also be suppressed by host cell factor 1 (HCF1), and the hitherto poorly characterized HCF2, which themselves are not degraded but can bind and block the substrate-binding domain (SBD) of Siah1/2 to prevent their autoubiquitination and trans-ubiquitination of downstream targets including ELL2. This effect stabilizes ELL2 and enhances the ELL2-SEC formation for robust HIV-1 transactivation. Thus, our study not only identifies HCF1/2 as novel activators of HIV-1 transcription through inhibiting Siah1 to stabilize ELL2, but also reveals the SBD of Siah1/2 as a previously unrecognized new target for HCF1/2 to exert this inhibition.

Prognostic Role of microRNA-205 in Human Gynecological Cancer: A Meta-Analysis of Fourteen Studies

Several studies have revealed that miR-205 plays important roles in the development of gynecological cancers and thus may serve as a potential prognostic biomarker, but the current conclusions remain controversial. Therefore, the goal of this study was to explore the prognostic significance and functional mechanisms of miR-205 based on a meta-analysis and bioinformatics investigation. A total of 14 published studies containing 5835 patients were enrolled by searching the PubMed, EMBASE, and Cochrane library databases, 13 (14 datasets) and 5 (6 datasets) of which evaluated the correlations between the expression level of miR-205 and overall survival (OS) or disease-free survival (DFS)/disease-specific survival (DSS)/progression-free survival (PFS)/distant metastasis-free survival (DMFS), respectively. Furthermore, the use of online Kaplan-Meier plotter database analysis supplemented another seven results for OS. Then, a meta-analysis using these 21 and 6 datasets was performed. As a result, the overall analysis failed to demonstrate any significant associations between miR-205 expression and OS (p = 0.267) or DSS/DFS/DMFS/PFS (p = 0.457), but the subgroup analysis suggested that elevated miR-205 predicted a reduced OS for breast cancer (BC) patients (hazard ratio [HR] = 0.84, 95% confidence interval [CI] = 0.72-0.98; p = 0.022), while higher miR-205 was associated with a poor DSS for endometrial cancer (EC) patients (HR = 2.19, 95% CI = 1.45-3.32; p < 0.001). Function prediction analysis indicated that miR-205 may be involved in BC by negatively influencing hub genes, SMARCA5 and SIAH1, whereas miR-205 may participate in EC by negatively modulating BMPR1B because of the presence of interactions of miR-205 with them at 3'-untranslated region and their opposite prognosis outcomes with miR-205. In conclusion, our findings suggest miR-205 may be a promising prognostic biomarker and therapeutic target for BC and EC patients.

miRNAs as Biomarkers in Disease: Latest Findings Regarding Their Role in Diagnosis and Prognosis

MicroRNAs (miRNAs) represent a class of small, non-coding RNAs with the main roles of regulating mRNA through its degradation and adjusting protein levels. In recent years, extraordinary progress has been made in terms of identifying the origin and exact functions of miRNA, focusing on their potential use in both the research and the clinical field. This review aims at improving the current understanding of these molecules and their applicability in the medical field. A thorough analysis of the literature consulting resources available in online databases such as NCBI, PubMed, Medline, ScienceDirect, and UpToDate was performed. There is promising evidence that in spite of the lack of standardized protocols regarding the use of miRNAs in current clinical practice, they constitute a reliable tool for future use. These molecules meet most of the required criteria for being an ideal biomarker, such as accessibility, high specificity, and sensitivity. Despite present limitations, miRNAs as biomarkers for various conditions remain an impressive research field. As current techniques evolve, we anticipate that miRNAs will become a routine approach in the development of personalized patient profiles, thus permitting more specific therapeutic interventions.

iTRAQ-based quantitative proteomic analysis of the inhibition of cervical cancer cell invasion and migration by metformin

In recent years the anti-diabetic drug metformin has been shown to inhibit tumor growth, but the underlying mechanism is unclear. Our previous results showed that metformin can destroy the sponge effect of long-chain non-coding RNA MALAT1/miR-142-3p and inhibit the proliferation of cervical cancer cells. Metformin can inhibit the PI3K/Akt signaling pathway and synergizes with Nelfinavir to inhibit the proliferation and invasion of cervical cancer cells. In this study, we used iTRAQ-based proteomics, mass spectrometry-based targeted proteomics, immunoblotting, and bioinformatics to analyze the molecular mechanism by which metformin inhibits the proliferation and invasion of cervical cancer cells. We found that 53 proteins were differentially expressed in cervical cancer cells after metformin treatment, of which 20 were up-regulated and 33 were down-regulated. Bioinformatics analysis showed that the 53 differentially expressed proteins are negative regulators of receptor signaling that inhibit cell growth and are mainly enriched in cell growth and apoptosis signaling pathways. We performed PRM verification on 11 of the differentially expressed proteins and found that they were all associated with apoptosis. We also found that metformin up-regulated the expression of the tumor suppressor IGFBP7 to inhibit the proliferation and invasion of cervical cancer cells. Our results indicate that metformin mainly regulates the insulin signaling pathway and interferes with cell proliferation and apoptosis to inhibit proliferation and invasion of cervical cancer cells. These differentially expressed proteins may become new targets for the treatment of cervical cancer.

Dynamic Regulation of miRNA Expression by Functionally Enhanced Placental Mesenchymal Stem Cells PromotesHepatic Regeneration in a Rat Model with Bile Duct Ligation

Placenta-derived mesenchymal stem cells (PD-MSCs) were highlighted as therapeutic sources in several degenerative diseases. Recently, microRNAs (miRNAs)were found to mediate one of the therapeutic mechanisms of PD-MSCs in regenerative medicine. To enhance the therapeutic effects of PD-MSCs, we established functionally enhanced PD-MSCs with phosphatase of regenerating liver-1 overexpression (PRL-1(+)). However, the profile and functions of miRNAs induced by PRL-1(+) PD-MSCs in a rat model with hepatic failure prepared by bile duct ligation (BDL) remained unclear. Hence, the objectives of the present study were to analyze the expression of miRNAs and investigate their therapeutic mechanisms for hepatic regeneration via PRL-1(+) in a rat model with BDL. We selected candidate miRNAs based on microarray analysis. Under hypoxic conditions, compared with migrated naïve PD-MSCs, migrated PRL-1(+) PD-MSCs showed improved integrin-dependent migration abilitythrough Ras homolog (RHO) family-targeted miRNA expression (e.g., hsa-miR-30a-5p, 340-5p, and 146a-3p). Moreover, rno-miR-30a-5p and 340-5p regulated engraftment into injured rat liver by transplantedPRL-1(+) PD-MSCs through the integrin family. Additionally, an increase inplatelet-derived growth factor receptor A (PDGFRA) by suppressing rno-miR-27a-3p improved vascular structure in rat liver tissues after PRL-1(+) PD-MSC transplantation. Furthermore, decreased rno-miR-122-5p was significantly correlated with increased proliferation of hepatocytes in liver tissues by PRL-1(+) PD-MSCs byactivating the interleukin-6 (IL-6) signaling pathway through the repression of rno-miR-21-5p. Taken together, these findings improve the understandingof therapeutic mechanisms based on miRNA-mediated stem-cell therapy in liver diseases.

HNRNPA2/B1 is upregulated in endocrine-resistant LCC9 breast cancer cells and alters the miRNA transcriptome when overexpressed in MCF-7 cells

MicroRNAs are dysregulated in breast cancer. Heterogeneous Nuclear Ribonucleoprotein A2/B1 (HNRNPA2/B1) is a reader of the N(6)-methyladenosine (m6A) mark in primary-miRNAs (pri-miRNAs) and promotes DROSHA processing to precursor-miRNAs (pre-miRNAs). We examined the expression of writers, readers, and erasers of m6A and report that HNRNPA2/B1 expression is higher in tamoxifen-resistant LCC9 breast cancer cells as compared to parental, tamoxifen-sensitive MCF-7 cells. To examine how increased expression of HNRNPA2/B1 affects miRNA expression, HNRNPA2/B1 was transiently overexpressed (~5.4-fold) in MCF-7 cells for whole genome miRNA profiling (miRNA-seq). 148 and 88 miRNAs were up- and down-regulated, respectively, 48 h after transfection and 177 and 172 up- and down-regulated, respectively, 72 h after transfection. MetaCore Enrichment analysis identified progesterone receptor action and transforming growth factor β (TGFβ) signaling via miRNA in breast cancer as pathways downstream of the upregulated miRNAs and TGFβ signaling via SMADs and Notch signaling as pathways of the downregulated miRNAs. GO biological processes for mRNA targets of HNRNPA2/B1-regulated miRNAs included response to estradiol and cell-substrate adhesion. qPCR confirmed HNRNPA2B1 downregulation of miR-29a-3p, miR-29b-3p, and miR-222 and upregulation of miR-1266-5p, miR-1268a, miR-671-3p. Transient overexpression of HNRNPA2/B1 reduced MCF-7 sensitivity to 4-hydroxytamoxifen and fulvestrant, suggesting a role for HNRNPA2/B1 in endocrine-resistance.

Integrating microRNA and mRNA expression in rapamycin-treated T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) has a relatively improved remission rate, but the poor outcomes are primarily due to resistance and relapse. Moreover, organs infiltration trends to occur during remission. Rapamycin was applied to treat malignancies for decades. In this investigation, we aimed to explore the molecular mechanisms and pathway changes during the T-ALL therapeutic process. T-ALL cell line Molt-4 cells were treated with rapamycin and performed microarray analysis to identify the deregulated miRNAs and mRNAs (log2 fold change>2 or <-2). To obtain regulatory miRNA/mRNA network, miRNA target prediction softwares and Cytoscape were used to plot and modularize the rapamycin treatment-related network. Surprisingly, the enriched pathways were not involved in mediating either cell death or apoptosis but were responsible for angiogenesis, cell survival, and anti-apoptosis, which is consistent with the Gene Ontology analysis and PPI network based on all deregulated mRNAs, indicating that these elements likely play a role in promoting Molt-4 cell survival or escaping from rapamycin. The expression of 3 miRNAs (miR-149-3p, miR-361-3p, and miR-944) and their putative targets, which play central roles in their module, were validated by qRT-PCR. These results provide novel insight into potentially relevant biological pathways for T-ALL cells escaping from chemotherapy or developing central nervous system infiltration.

microRNA-944 overexpression is a biomarker for poor prognosis of advanced cervical cancer

Background

One-third of cervical cancer patients are still diagnosed at advanced stages. The five-year survival rate is decreased in about 50% of advanced stage cervical cancer patients worldwide, and the clinical outcomes are remarkably varied and difficult to predict. One of the miRNAs known to be associated with cancer tumorigenesis is miR-944. However, the prognostic value of miR-944 in cervical cancer has not been fully investigated. The aim of this study was to analyze clinical significance and prognostic value of miR-944 in cervical cancer.

Methods

The expression levels of miR-944 were detected using quantitative reverse transcription polymerase chain reaction in five types of cervical cancer cell lines and 116 formalin-fixed paraffin-embedded (FFPE) cervical tissues. The association between the expression levels of miR-944 and prognostic value was analyzed using the Kaplan-Meier analysis and Cox proportional hazards model.

Results

The expression levels of miR-944 in cervical cancer tissues were significantly higher compared with those in normal tissues (P < 0.0001). Moreover, the expression levels of miR-944 in cervical cancer cell lines and FFPE tissues with human papillomavirus (HPV) infection were significantly higher compared to those without HPV infection (P < 0.01 and P = 0.02). High miR-944 expression was also markedly associated with bulky tumor size (P = 0.026), advanced International Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.042), and lymph node metastasis (P = 0.030). In particular, high miR-944 expression group showed shorter overall survival than the low miR-944 expression group in the advanced FIGO stage (84.4% vs. 44.4%, HR = 4.0, and P = 0.01).

Conclusions

These results suggest that miR-944 may be used as a novel biomarker for improving prognosis and as a potential therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5620-6) contains supplementary material, which is available to authorized users.

Ectopic expression of miR-944 impairs colorectal cancer cell proliferation and invasion by targeting GATA binding protein 6

miR-944 is a microRNA that has been reported to play different important roles in the progression of cancer. Colorectal cancer (CRC) is a common cancer worldwide. A recent study has confirmed that miR-944 plays a tumour suppressive role in CRC. However, biological functions and the mechanism of miR-944 in CRC are poorly understood. Real-time reverse transcription polymerase chain reaction of 100 CRC tissues showed that miR-944 expression is frequently downregulated and is negatively associated with the T is the primary tumor, N is the lymph node, and M is the distant metastasis (TNM) stage (P = 0.009), depth of invasion (P = 0.001), and lymph node status (P = 0.002). Overexpression of mir-944 significantly impaired the functions of proliferation, migration and invasion in CRC cells, while these functions increased in knockdown experiments. GATA binding protein 6 (GATA6) knockdown can reverse the CRC cells functions induced by miR-944 inhibitor. Mechanistically, a Dual-Luciferase Reporter Assay showed that miR-944 is structurally combined with GATA6 and interacts with downstream proteins (CRT and p-AKT) in CRC cells. In conclusion, these findings indicated that miR-944 may be a tumour suppressor and could likely be used as a prognostic predictor and novel therapeutic target for CRC.

Knockdown of miR-299-5p inhibits the progression of hepatocellular carcinoma by targeting SIAH1

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. MiR-299-5p has been demonstrated to play important roles in multiple human cancers. Nevertheless, little is known about the detailed function and molecular mechanism of miR-299-5p on HCC progression.

METHODS

Quantitative real-time PCR (qRT-PCR) assay was used to assess the expression patterns of miR-299-5p and siah E3 ubiquitin protein ligase 1 (SIAH1) in HCC tissues and cell lines. Loss-of-function experiments were performed to explore the effect of miR-299-5p on HCC progression in vitro and in vivo. Target predicted by software algorithms, the connection between miR-299-5p and SIAH1 was verified by dual-luciferase reporter assay, qRT-PCR and western blot analysis. Subsequently, anti-miR-299-5p and si-SIAH1 were cotransfected into LM9 and Huh-7 cells to further explore whether the regulatory effect of miR-299-5p on HCC was mediated by SIAH1.

RESULTS

qRT-PCR assay revealed that miR-299-5p was upregulated and SIAH1 was downregulated in HCC tissues and cell lines. Moreover, miR-299-5p knockdown suppressed HCC progression in vitro and in vivo. In addition, anti-miR-299-5p-mediated regulatory effect on HCC cells was abated following the restoration of SIAH1 expression.

CONCLUSIONS

MiR-299-5p knockdown suppressed the progression of HCC by targeting SIAH1, highlighting its role as a potential biomarker and therapeutic target of HCC.

miR-944 inhibits cell migration and invasion by targeting MACC1 in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common disease in Southern China with high prevalence. miR-944 has been reported to play a vital role in progression of a variety of cancers. The present study aimed to investigate the potential role of miR-944 in NPC cell migration and invasion through elucidating the interaction with its target genes, MACC1. Expression of miR-944 in NPC tissues and cell lines was examined with quantitative RT-PCR. Overexpressed miR-944 and suppressed miR-944 were established with miR-944 mimics and miR-944 inhibitor, respectively. The effect of miR-944 on cell migration and invasion was determined using Transwell cell migration and Matrigel invasion assay. Luciferase assay was used to determine the target of miR-944. Knocked down of MACC1 was done by MACC1 siRNA. Expression of MET related-markers was examined using Western blot analysis. The expression level of miR-944 was downregulated in NPC tissues and cell lines. Overexpression of miR-944 significantly inhibited the cell migration and invasion in NPC 6-10B cells. In contrast, suppression of miR-944 promoted cell migration and invasion in NPC C-6661 cells. MACC1 is a direct target of miR-944. MACC1 expression was repressed in miR-944 mimic transfected cells while it was enhanced in miR-944 inhibitor transfected cells. MACC1 knock down inhibited cell migration and invasion. Either miR-944 restoration or MACC1 knockdown caused enhanced E-cadherin, reduced N-cadherin, and vimentin expression. In conclusion, miR-944 could inhibit MET and metastasis of NPC by targeting MACC1. This study suggests that miR-944 has anti-tumor and anti- metastatic properties and could thus be a novel therapeutic agent for NPC treatment.

MicroRNA-1271 functions as a metastasis and epithelial-mesenchymal transition inhibitor in human HCC by targeting the PTP4A1/c-Src axis

MicroRNAs (miRNAs or miRs) have been shown to regulate hepatocellular carcinoma (HCC) metastasis. In the present study, we focused on the functions of miR-1271 in HCC metastasis. The downregulation of miR-1271 was found to be associated with to venous infiltration, an advanced TNM stage (III+IV stage) and a shorter survival time. Our in vitro and in vivo data demonstrated that miR-1271 prevented HCC cell migration and invasion, as well as the formation of lung metastatic clusters. In addition, miR-1271 was demonstrated to markedly inhibit the epithelial-mesenchymal transition (EMT) of HCC cells. Importantly, protein tyrosine phosphatase type IVA member 1 (PTP4A1) was identified as a direct downstream target of miR-1271 in HCC. Furthermore, we confirmed that the phosphorylation of c-Src at Tyr416 mediated by PTP4A1 was a potential anti-HCC mechanism of action of miR-1271. On the whole, our data indicate that miR-1271 inhibits HCC metastasis by targeting the PTP4A1/c-Src signaling pathway and may serve as a prospective cancer therapeutic target for HCC.

New Insight into microRNA Functions in Cancer: Oncogene-microRNA-Tumor Suppressor Gene Network

Tumorigenesis is a multi-step and complex process with multi-factors involved. Deregulated oncogenes and tumor suppressor genes (TSGs) induced by genetic and epigenetic factors are considered as the driving force in the development and progression of cancer. Besides, microRNAs (miRNAs) act vital roles in tumorigenesis through regulating some oncogenes and TSGs. Interestingly, miRNAs are also regulated by oncogenes and TSGs. Considering the entangled regulation, here we propose a new insight into these regulation relationships in cancer: oncogene–miRNA–TSG network, which further emphasizes roles of miRNA, as well as highlights the network regulation among oncogene, miRNA, and TSG during tumorigenesis. The oncogene–miRNA–TSG network demonstrates that oncogenes and TSGs not only show functional synergy, but also there are regulatory relationships among oncogenes and TSGs during tumorigenesis, which could be mediated by miRNAs. In view of the oncogene–miRNA–TSG network involved in many oncogenes, miRNAs, and TSGs, as well as occurring in various tumor types, the anomaly of this network may be a common event in cancers and participates in tumorigenesis. This hypothesis broadens horizons of molecular mechanisms underlying tumorigenesis, and may provide a new promising venue for the prediction, diagnosis, and even therapy of cancer.

miR-944 inhibits metastasis of gastric cancer by preventing the epithelial-mesenchymal transition via MACC1/Met/AKT signaling

MicroRNAs (miRNAs) are reported to play vital roles in tumor progression. Recently, miR-944 was reported to play either an oncogenic or tumor suppressive role in human cancers. However, the expression of miR-944 and its exact role in gastric cancer (GC) remain unknown. This study aimed to evaluate whether loss of miR-944 could promote the epithelial-mesenchymal transition (EMT) of GC. Reduced expression of miR-944 was identified in 40 pairs of human GC and matched normal tissues by qRT-PCR. Reduced expression of mi-944 was also observed in GC cell lines. Restoration of miR-944 inhibited cell migration and invasion in MGC-803 cells, while its loss facilitated metastasis of SGC-7901 and BGC-823 cells. Notably, miR-944 overexpression prohibited EMT of GC cells in vitro, while miR-944 knockdown had the opposite effect. Bioinformatics software predicted that MACC1 was a direct target of miR-944. We observed negative regulation of miR-944 on MACC1 expression, and direct binding between miR-944 and MACC1 was verified by dual-luciferase assays in HEK293T cells. Restoration of MACC1 resulted in promoted EMT and metastasis in miR-944-overexpressing MGC-803 cells. Loss of MACC1 abrogated the effects of miR-944 knockdown on EMT and metastasis of SGC-7901 cells. We also found that the Met-AKT pathway might be involved in MACC1-mediated EMT. In conclusion, miR-944 acts as an inhibitor of EMT and metastasis of GC by targeting MACC1. This study highlights the potential effects of miR-944 in the prognosis and treatment of GC.

miR-944 inhibits cell migration and invasion by targeting MACC1 in colorectal cancer

Dysfunction of microRNAs (miRNAs) is strongly proved to participate in the pathogenesis and tumorigenicity of colorectal cancer (CRC). miR-944 was reported to play either oncogenic or tumor suppressive roles in human cancers. A recent study reported that the levels of miR-944 in recurrent CRC patients were evidently lower than that in non-recurrent cases, suggesting that miR-944 may function as a tumor suppressive miRNA in CRC. Yet, the clinical value and biological function of miR-944 remain rarely known in CRC. In the present study, we present that miR-944 level in CRC tissues is notably reduced compared to matched non-cancerous specimens. Its decreased level is evidently correlated with malignant clinical parameters and poor prognosis of CRC patients. Accordingly, the levels of miR-944 were obviously downregulated in CRC cells. Ectopic expression of miR-944 in CRC cells prominently inhibits the migration and invasion of tumor cells, while miR-944 knockdown increased these effects of CRC cells. Mechanically, miR-944 negatively regulated the metastasis-associated in colon cancer-1 (MACC1) abundance in CRC cells. Herein, MACC1 was found to be a downstream molecule of miR-944 in CRC. An inversely correlation between miR-944 and MACC1 was confirmed in CRC specimens. Furthermore, restoration of MACC1 expression could abrogate the anti-metastatic effects of miR-944 on CRC cells with enhanced cell migration and invasion. MACC1/Met/AKT signaling may be implicated with the function of miR-944 in CRC cells. Altogether, miR-944 potentially act as a prognostic predictor and a drug-target for CRC patients.

Expression of miR-944 in esophageal squamous cell carcinoma and its role in cell proliferation and invasion in human esophageal carcinoma cell line Eca109

AIM

To detect the expression of miRNA-944 in esophageal squamous cell carcinoma (ESCC), and to explore its role in cell proliferation and migration in human esophageal cancer cell line Eca109.

METHODS

ESCC and matched tumor adjacent noncancerous tissue samples were obtained from 36 patients who underwent surgical treatment and were pathologically diagnosed with ESCC. Real-time quantitative PCR (qRT-PCR) was used to detect the expression levels of miRNA-944, and the relationship between miRNA-944 and clinical and pathological parameters were then analyzed. Eca109 cells were transfected with miR-944 mimic, inhibitor and negative control using LipofectamineTM2000, and then the expression level of miR-944 was detected by qRT-PCR. Cell proliferation and invasion were assessed by MTT assay and transwell assay, respectively.

RESULTS

The expression level of miR-944 in ESCC tissues was significantly higher than that in tumor adjacent non-cancerous tissues (P < 0.01).The up-regulation of miR-944 expression in ESCC was correlated with advanced TNM stage (P < 0.01) and lymph node metastasis (P < 0.01). Compared to control cells, transfection of miR-944 mimic and inhibitor up- and down-regulated miR-944 expression in Eca109 cells, respectively (P < 0.01). Furthermore, transfection of miR-944 mimic enhanced cell proliferation and invasion, while transfection of miR-944 inhibitor inhibited cell proliferation and invasion (P < 0.01).

CONCLUSION

The expression of miR-944 is up-regulated in ESCC and associated with TNM stage and lymph node metastasis, indicating that miR-944 may facilitate ESCC occurrence possibly by promoting the proliferation and invasion of ESCC cells.