miR-29b suppresses tumor growth and metastasis in colorectal cancer via downregulating Tiam1 expression and inhibiting epithelial-mesenchymal transition. Cell Death Dis. 2014;5:e1335. [PMID: 25032858 PMCID: PMC4123095 DOI: 10.1038/cddis.2014.304]

The prognostic and therapeutic potential of vimentin in colorectal cancer

Several cells and molecules in the tumor microenvironment have been introduced as effective factors in the prognosis and progression of colorectal cancer. As a key element of the intermediate filament family, vimentin is expressed by mesenchymal cells in a ubiquitous manner and contributes significantly to cellular integrity and stress resistance in colorectal cancer. Recent studies have shown that alterations in the expression patterns of intermediate filaments are significantly related to cancer progression, especially in phenotypes associated with cellular migration and invasion. In addition to its multiple biological roles, vimentin also has a substantial function in mediating the epithelial-mesenchymal transition. Therefore, evaluating vimentin as an effective factor involved in the prognosis of colorectal cancer and targeting it as a novel approach to cancer therapy have become one of the main goals of many researchers worldwide. In this article, we will review the various biological functions of vimentin, as well as its relationship with colorectal cancer with the aim of providing novel insights into its clinical importance in the prognosis and treatment of colorectal cancer.

CAFs-derived TIAM1 Promotes OSCC Cell Growth and Metastasis by Regulating ZEB2

Previous studies have suggested that cancer-associated fibroblasts (CAFs) within the tumor microenvironment are a critical factor in tumorigenesis and tumor development. However, the regulatory mechanisms of CAFs on oral squamous cell carcinoma (OSCC) are poorly defined. A CAF-conditioned medium (CAF-CM) was collected and applied to culture OSCC cells. Then, cell viability, proliferation, migration, and invasion were evaluated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and scratch healing assays. T-Lymphoma Invasion and Metastasis 1 (TIAM1), zinc finger E-box-binding homeobox 2 (ZEB2), E-cadherin, and increased N-cadherin protein levels were determined using western blot. TIAM1 and ZEB2 mRNA levels were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Their interaction was analyzed using Co-immunoprecipitation (Co-IP) assay. SCC25 cells with or without (TIAM1-silencing) CAFs were subcutaneously inoculated in nude mice to assess the effect of TIAM1 in CAFs on OSCC tumor growth in vivo. CAFs expedited OSCC cell proliferation, migration, invasion, and EMT. TIAM1 and ZEB2 expression were upregulated in OSCC patients and OSCC cells, and the TIAM1 level was much higher in CAFs than in OSCC cells. Furthermore, TIAM1 knockdown in CAFs might partly abolish the promotion of CAFs on OSCC cell development, implying that TIAM1 might be secreted by CAFs into the culture medium to exert its effects inside OSCCs. TIAM1 might increase ZEB2 expression, and ZEB2 upregulation might partly reverse the repression of TIAM1 silencing in CAFs on OSCC cell malignant behaviors. In vivo studies confirmed that CAFs accelerated OSCC tumor growth, these effects were partially counteracted by TIAM1 downregulation. Overall, TIAM1 secreted by CAFs could expedite OSCC cell growth and metastasis by regulating ZEB2, providing a promising therapeutic target for OSCC treatment.

miR-29b-3p targetedly regulates VEGF to inhibit tumor progression and cisplatin resistance through Nrf2/HO-1 signaling pathway in non-small cell lung cancer

BACKGROUNDS

Non-small cell lung carcinoma (NSCLC) is a common type of lung cancer. Prior investigations have elucidated the pivotal role of miR-29b-3p in restraining tumor growth and metastasis. Nonetheless, it remains to be determined whether miR-29b-3p can effectively suppress NSCLC progression and enhance the sensitivity of NSCLC cells to cisplatin. This investigation sought to determine the mechanism by which miR-29b-3p inhibited the advancement of NSCLC and mitigated resistance to cisplatin.

METHODS

We initially assessed miR-29b-3p and VEGF levels in NSCLC tissues and cell lines. Next, miR-29b-3p expression was elevated in NSCLC cell lines H1975 and A549 by overexpression plasmid transfection. Following this, a sequence of molecular biology experiments was conducted to evaluate the impact of miR-29b-3p on the biological behaviors of NSCLC cells and their resistance to cisplatin. Additionally, we predicted VEGF was a target gene of miR-29b-3p by bioinformatics analysis. We next employed western blot to evaluate the protein expression of Nrf2 and HO-1 in NSCLC cells. Finally, we elucidated the effects of VEGF and Nrf2/HO-1pathway on NSCLC progression and cisplatin resistance by in vitro assays.

RESULTS

In comparison to paracancerous tissues and human normal lung epithelial cells, the expression of miR-29b-3p was notably reduced and VEGF expression was clearly elevated in NSCLC tissues and cells. Moreover, miR-29b-3p upregulated obviously suppressed the biological activities of NSCLC cells and increased their sensitivity to cisplatin. Furthermore, in NSCLC cells, miR-29b-3p bound to VEGF and negatively regulate its transcription. Additionally, miR-29b-3p overexpression also inhibited the Nrf2/HO-1 signaling pathway. Finally, the overexpression of VEGF and the activation of the Nrf2/HO-1 pathway reversed miR-29b-3p-mediated inhibitory effect on biological behaviors of NSCLC cells and increased the cisplatin resistance.

CONCLUSION

Our findings indicate that miR-29b-3p impedes NSCLC cells' biological behaviors and augments their sensitivity to cisplatin by targeting VEGF to modulate the Nfr2/HO-1 signaling pathway.

Dbl family RhoGEFs in cancer: different roles and targeting strategies

Small Ras homologous guanosine triphosphatase (Rho GTPase) family proteins are highly associated with tumorigenesis and development. As intrinsic exchange activity regulators of Rho GTPases, Rho guanine nucleotide exchange factors (RhoGEFs) have been demonstrated to be closely involved in tumor development and received increasing attention. They mainly contain two families: the diffuse B-cell lymphoma (Dbl) family and the dedicator of cytokinesis (Dock) family. More and more emphasis has been paid to the Dbl family members for their abnormally high expression in various cancers and their correlation to poor prognosis. In this review, the common and distinctive structures of Dbl family members are discussed, and their roles in cancer are summarized with a focus on Ect2, Tiam1/2, P-Rex1/2, Vav1/2/3, Trio, KALRN, and LARG. Significantly, the strategies targeting Dbl family RhoGEFs are highlighted as novel therapeutic opportunities for cancer.

m6A/HOXA10-AS/ITGA6 axis aggravates oxidative resistance and malignant progression of laryngeal squamous cell carcinoma through regulating Notch and Keap1/Nrf2 pathways

As the second most prevalent malignant tumor of head and neck, laryngeal squamous cell carcinoma (LSCC) imposes a substantial health burden on patients worldwide. Within recent years, resistance to oxidative stress and N6-methyladenosine (m6A) of RNA have been proved to be significantly involved in tumorigenesis. In current study, we investigated the oncogenic role of m6A modified long non coding RNAs (lncRNAs), specifically HOXA10-AS, and its downstream signaling pathway in the regulation of oxidative resistance in LSCC. Bioinformatics analysis revealed that heightened expression of HOXA10-AS was associated with the poor prognosis in LSCC patients, and N (6)-Methyladenosine (m6A) methyltransferase-like 3 (METTL3) was identified as a factor in promoting m6A modification of HOXA10-AS and further intensify its RNA stability. Mechanistically, HOXA10-AS was found to play as a competitive endogenous RNA (ceRNA) by sequestering miR-29 b-3p and preventing its downregulation of Integrin subunit alpha 6 (ITGA6), ultimately enhancing the oxidative resistance of tumor cells and promoting the malignant progression of LSCC. Furthermore, our research elucidated the mechanism by which ITGA6 accelerates Keap1 proteasomal degradation via enhancing TRIM25 expression, leading to increased Nrf2 stability and exacerbating its aberrant activation. Additionally, we demonstrated that ITGA6 enhances γ-secretase-mediated Notch signaling activation, ultimately promoting RBPJ-induced TRIM25 transcription. The current study provides the evidence supporting the effect of m6A modified HOXA10-AS and its downstream miR-29 b-3p/ITGA6 axis on regulating oxidative resistance and malignant progression in LSCC through the Notch and Keap1/Nrf2 pathways, and proposed that targeting this axis holds promise as a potential therapeutic approach for treating LSCC.

Role of Angiogenesis and Its Biomarkers in Development of Targeted Tumor Therapies

Angiogenesis plays a significant role in the human body, from wound healing to tumor progression. "Angiogenic switch" indicates a time-restricted event where the imbalance between pro- and antiangiogenic factors results in the transition from prevascular hyperplasia to outgrowing vascularized tumor, which eventually leads to the malignant cancer progression. In the last decade, molecular players, i.e., angiogenic biomarkers and underlying molecular pathways involved in tumorigenesis, have been intensely investigated. Disrupting the initiation and halting the progression of angiogenesis by targeting these biomarkers and molecular pathways has been considered as a potential treatment approach for tumor angiogenesis. This review discusses the currently known biomarkers and available antiangiogenic therapies in cancer, i.e., monoclonal antibodies, aptamers, small molecular inhibitors, miRNAs, siRNAs, angiostatin, endostatin, and melatonin analogues, either approved by the U.S. Food and Drug Administration or currently under clinical and preclinical investigations.

Epigenetic and metabolic reprogramming in inflammatory bowel diseases: diagnostic and prognostic biomarkers in colorectal cancer

BACKGROUND AND AIM

"Inflammatory bowel disease" (IBD) is a chronic, relapsing inflammatory disease of the intestinal tract that typically begins at a young age and might transit to colorectal cancer (CRC). In this manuscript, we discussed the epigenetic and metabolic change to present a extensive view of IBDs transition to CRC. This study discusses the possible biomarkers for evaluating the condition of IBDs patients, especially before the transition to CRC.

RESEARCH APPROACH

We searched "PubMed" and "Google Scholar" using the keywords from 2000 to 2022.

DISCUSSION

In this manuscript, interesting titles associated with IBD and CRC are discussed to present a broad view regarding the epigenetic and metabolic reprogramming and the biomarkers.

CONCLUSION

Epigenetics can be the main reason in IBD transition to CRC, and Hypermethylation of several genes, such as VIM, OSM4, SEPT9, GATA4 and GATA5, NDRG4, BMP3, ITGA4 and plus hypomethylation of LINE1 can be used in IBD and CRC management. Epigenetic, metabolisms and microbiome-derived biomarkers, such as Linoleic acid and 12 hydroxy 8,10-octadecadienoic acid, Serum M2-pyruvate kinase and Six metabolic genes (NAT2, XDH, GPX3, AKR1C4, SPHK and ADCY5) expression are valuable biomarkers for early detection and transition to CRC condition. Some miRs, such as miR-31, miR-139-5p, miR -155, miR-17, miR-223, miR-370-3p, miR-31, miR -106a, miR -135b and miR-320 can be used as biomarkers to estimate IBD transition to CRC condition.

EVADR ceRNA transcript variants upregulate WNT and PI3K signaling pathways in SW480 and HCT116 cells by sponging miR-7 and miR-29b

Long noncoding RNAs are cancer regulators and EVADR-lncRNA is highly upregulated in colorectal cancer (CRC). Accordingly, we aimed to functionally characterize the EVADR in CRC-originated cells. Firstly, during the amplification of EVADR full-length cDNA (named EVADR-v1), a novel/shorter variant (EVADR-v2) was discovered. Then, RT-qPCR analysis confirmed that EVADR is upregulated in tumors, consistent with RNA-seq analysis. Interestingly, bioinformatics analysis and dual-luciferase assay verified that EVADR sponges miR-7 and miR-29b. When both EVADR-v1/-v2 variants were overexpressed in SW480/HCT116 cells, miR-7 and miR-29b target genes (involved in the WNT/PI3K signaling) were upregulated. Furthermore, EVADR-v1/-v2 overexpression resulted in elevated PI3K activity (verified by western blotting and RT-qPCR) and upregulation of WNT signaling (confirmed by western blotting, TopFlash assay, and RT-qPCR). Consistently, overexpression of EVADR-v1/-v2 variants was followed by increased cell cycle progression, viability and migration as well as reduced early/late apoptotic rate, and Bax/Bcl2 ratio of the CRC cells, detected by the cell cycle analysis, MTT, wound-healing, Annexin-V/PI, and RT-qPCR methods, respectively. Overall, we introduced two oncogenic transcript variants for EVADR that by sponging miR-7/miR-29b, upregulate WNT and PI3K signaling. Given the crucial role of these pathways in CRC, EVADR may present potential therapy use.

Down-regulated MiRNA 29-b as a diagnostic marker in colorectal cancer and its correlation with ETV4 and Cyclin D1 immunohistochemical expression

BACKGROUND

Colorectal cancer (CRC) is the most common malignant tumor of the gastrointestinal tract with unfavorable prognosis. Therefore, novel biomarkers that may be used for new diagnostic strategies and drug-targeting therapy should be developed.

OBJECTIVES

To investigate the expression of miR-29b in CRC and its association with ETV4 and cyclin D1 expression. Moreover, the current work aims to investigate the association between them and the clinicopathological features of CRC.

METHODS

The expression of miR-29b and ETV4 (by qRT-PCR) and ETV4 and cyclin D1 (immunohistochemistry) was investigated in 65 cases of colon cancer and surrounding healthy tissues.

RESULTS

MiR-29b down-regulated and ETV4 and Cyclin D1 up-regulated significantly in colon cancer tissues compared to normal nearby colonic tissues. In addition, significant associations between ETV4 and cyclin D1 expressions and progressive stage and lymph node (LN) metastasis (P< 0.001 for each) were found. Furthermore, there was a negative correlation between miR-29b gene expression and ETV4 gene expression (r=-0.298, P<0.016).

CONCLUSION

Down-regulation of miR-29b and over-expression of ETV4 and cyclin D1 may be utilized as early diagnostic marker for development of colon cancer. ETV4 and cyclin D1 correlate with poor prognostic indicators and considered as a possible target for therapy in colon cancer.

Role of let7-g and miR-221 level as potential predictors for overall survival of hepatocellular carcinoma patients

BACKGROUND AND STUDY AIMS

Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. A hallmark of epithelial-mesenchymal transition is the loss of epithelial E-cadherin, which is considered an epithelial differentiation marker. MicroRNAs serve vital roles in various biological processes in the cell via post-transcriptional gene regulation. Therefore, the present study aimed to investigate the involvement of certain miRNAs in the progression of HCC.

PATIENTS AND METHODS

A reverse transcription-quantitative PCR assay was conducted to detect the expression levels of 20 EMT-related miRNAs in 36 fresh tissue biopsies from patients with primary HCC compared with healthy controls. Gene expression levels, as well as immunohistochemistry assays, were performed for E-cadherin, ZEB1 and ZEB2 proteins. The correlation between their expression levels and different clinicopathological factors was also assessed.

RESULTS

A significant decrease of E-Cadherin and an increase in ZEB1 expression levels were identified in HCC groups compared with controls, while no significant changes for ZEB2 were found. The absence of E-cadherin membranous protein was observed in ∼48% of the cases examined. Moreover, ZEB1 protein was absent in 46% of E-cadherin positive cases. Upregulation of miR-182, miR-221 and miR-222 expression levels, and downregulation of let-7g, miR-9, miR-16, miR29c, miR122, miR-145, miR-148a, miR-193b, miR-194 and miR-215 expression levels were identified. A positive correlation between let7-g with E-Cadherin expression was reported. No significant association was identified between each of E-cadherin, ZEB1, ZEB2 or miRNAs examined with different clinicopathological features of the patients. Furthermore, the low expression of let7-g and high expression of miR-221 were associated with poorer survival.

CONCLUSION

Collectively, the present data suggested that let7-g functions as a tumor suppressor in the development of HCC via regulating E-Cadherin. Furthermore, both let7-g and miR-221 may be potential biomarkers for the outcomes of HCC patients.

Comprehensive analysis of EMT-related genes and lncRNAs in the prognosis, immunity, and drug treatment of colorectal cancer

BACKGROUND

EMT is an important biological process in the mechanism of tumor invasion and metastasis. However, there are still many unknowns about the specific mechanism of EMT in tumor. At present, a comprehensive analysis of EMT-related genes in colorectal cancer (CRC) is still lacking.

METHODS

All the data were downloaded from public databases including TCGA database (488 tumor samples and 52 normal samples) as the training set and the GEO database (GSE40967 including 566 tumor samples and 19 normal samples, GSE12945 including 62 tumor samples, GSE17536 including 177 tumor samples, GSE17537 including 55 tumor samples) as the validation sets. One hundred and sixty-six EMT-related genes (EMT-RDGs) were selected from the Molecular Signatures Database. Bioinformatics methods were used to analyze the correlation between EMT-RDGs and CRC prognosis, metastasis, drug efficacy, and immunity.

RESULTS

We finally obtained nine prognostic-related EMT-RDGs (FGF8, NOG, PHLDB2, SIX2, SNAI1, TBX5, TIAM1, TWIST1, TCF15) through differential expression analysis, Unicox and Lasso regression analysis, and then constructed a risk prognosis model. There were significant differences in clinical characteristics, 22 immune cells, and immune functions between the high-risk and low-risk groups and the different states of the nine prognostic-related EMT-RDGs. The methylation level and mutation status of nine prognostic-related EMT-RDGs all affect their regulation of EMT. The Cox proportional hazards regression model was also constructed by the methylation sites of nine prognostic-related EMT-RDGs. In addition, the expression of FGF8, PHLDB2, SIX2, and SNAIL was higher and the expression level of NOG and TWIST1 was lower in the non-metastasis CRC group. Nine prognostic-related EMT-RDGs also affected the drug treatment response of CRC.

CONCLUSIONS

Targeting these nine prognostic-related EMT-RDGs can regulate CRC metastasis and immune, which is beneficial for the prognosis of CRC patients, improve drug sensitivity in CRC patients.

miR‑29b suppresses proliferation and induces apoptosis of hepatocellular carcinoma ascites H22 cells via regulating TGF‑β1 and p53 signaling pathway

MicroRNA (miR)‑29b is a key tumor regulator. It can inhibit tumor cell proliferation, induce apoptosis, suppress tumor invasion and migration, thus delaying tumor progression. Our previous studies revealed an increased level of miR‑29b in hepatoma 22 (H22) cells in ascites tumor‑bearing mice. The present study investigated the effect of miR‑29b on proliferation and apoptosis of hepatocellular carcinoma ascites H22 cells and its association with the transforming growth factor‑β1 (TGF‑β1) signaling pathway and p53‑mediated apoptotic pathway. Briefly, H22 cells were transfected with miR‑29b‑3p (hereinafter referred to as miR‑29b) mimic or miR‑29b inhibitor. MTS cell proliferation assay and flow cytometry were used to analyze cell viability and apoptosis. The expression change of the TGF‑β1 signaling pathway and p53‑mediated apoptotic pathway were detected by reverse transcription‑quantitative PCR, western blotting and immunofluorescence. Furthermore, cells were treated with exogenous TGF‑β1 and TGF‑β1 small interfering RNA to evaluate the crosstalk between TGF‑β1 and p53 under miR‑29b regulation. The overexpression of miR‑29b decreased cell viability, increased cell apoptosis, activated the TGF‑β1 signaling pathway and p53‑mediated apoptotic pathway. Conversely, these effects were reversed by the miR‑29b inhibitor. Moreover, the effect of miR‑29b mimic was further increased after treating cells with exogenous TGF‑β1. The activation of the TGF‑β1 signaling pathway and p53‑mediated apoptotic pathway induced by miR‑29b overexpression were reversed by TGF‑β1 inhibition. In summary, these data indicated that miR‑29b has an important role in proliferation and apoptosis of H22 cells by regulating the TGF‑β1 signaling pathway, the p53‑dependent apoptotic pathway, and the crosstalk between TGF‑β1 and p53.

RBP-J promotes cell growth and metastasis through regulating miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis in colorectal cancer

BACKGROUND

RBP-J is involved in number of cellular processes. However, the potential mechanisms of RBP-J on colorectal cancer (CRC) development have not been clearly defined. In this study, we aimed to investigate the role and molecular mechanism of RBP-J in CRC.

METHODS

The expression levels of RBP-J and Tiam1 in CRC tissues and cells were evaluated by RT-qPCR or western blot. RBP-J was knocked down with sh-RBP-J or overexpressed by pcDNA3.1-RBP-J in CRC cells. Cell proliferation, migration and invasion abilities were analyzed by MTT, wound healing, and transwell assay, respectively. CHIP-qPCR, RIP and dual luciferase reporter assays were performed to confirm the interaction between miR-182-5p and RBP-J or Tiam1. Expression levels of p-p38 MAPK, p38 MAPK, Slug-1, Twist1 and MMP-9 were analyzed by western blot. G-LISA test was used to detect Rac1 activity.

RESULTS

Our results showed that the expression of RBP-J and Tiam1 was significantly up-regulated in CRC tissues and cells. RBP-J overexpression promoted proliferation, migration and invasion of CRC cells. Moreover, RBP-J was found to directly target miR-182-5p promoter and positively regulate the Tiam1/Rac1/p38 MAPK signaling pathway in CRC cells. It was also proved that miR-182-5p can bind Tiam1 directly. Furthermore, experiments revealed that RBP-J could promote CRC cell proliferation, migration and invasion via miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis. In addition, knockdown of RBP-J reduced tumor growth and metastasis in CRC mice.

CONCLUSION

RBP-J regulates CRC cell growth and metastasis through miR-182-5p mediated Tiam1/Rac1/p38 MAPK signaling pathway, implying potential novel therapeutic targets for CRC patients.

Gene Ontology Curation of Neuroinflammation Biology Improves the Interpretation of Alzheimer's Disease Gene Expression Data

BACKGROUND

Gene Ontology (GO) is a major bioinformatic resource used for analysis of large biomedical datasets, for example from genome-wide association studies, applied universally across biological fields, including Alzheimer's disease (AD) research.

OBJECTIVE

We aim to demonstrate the applicability of GO for interpretation of AD datasets to improve the understanding of the underlying molecular disease mechanisms, including the involvement of inflammatory pathways and dysregulated microRNAs (miRs).

METHODS

We have undertaken a systematic full article GO annotation approach focused on microglial proteins implicated in AD and the miRs regulating their expression. PANTHER was used for enrichment analysis of previously published AD data. Cytoscape was used for visualizing and analyzing miR-target interactions captured from published experimental evidence.

RESULTS

We contributed 3,084 new annotations for 494 entities, i.e., on average six new annotations per entity. This included a total of 1,352 annotations for 40 prioritized microglial proteins implicated in AD and 66 miRs regulating their expression, yielding an average of twelve annotations per prioritized entity. The updated GO resource was then used to re-analyze previously published data. The re-analysis showed novel processes associated with AD-related genes, not identified in the original study, such as 'gliogenesis', 'regulation of neuron projection development', or 'response to cytokine', demonstrating enhanced applicability of GO for neuroscience research.

CONCLUSIONS

This study highlights ongoing development of the neurobiological aspects of GO and demonstrates the value of biocuration activities in the area, thus helping to delineate the molecular bases of AD to aid the development of diagnostic tools and treatments.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.

Overexpression of microRNA-29b inhibits epithelial-mesenchymal transition and angiogenesis of colorectal cancer through the ETV4/ERK/EGFR axis

BACKGROUND

Recent studies have reported the involvement of microRNA-29 (miR-29) family members in human cancers through their ability to regulate cellular functions. The present study investigated biological function of miR-29b in colorectal cancer (CRC).

METHODS

CRC tissues and adjacent normal tissues were collected and the expression of ETV4 and miR-29b in the tissues were identified. The relationship between ETV4 and miR-29b or ETV4 expression and the EGFR promoter was identified using dual-luciferase reporter gene and CHIP assays. The proliferation, invasion, migration, and apoptosis of CRC HCT116 cells were assayed using MTT assay, Scratch test, Transwell assay, and flow cytometry, respectively. Also, expression of epithelial-mesenchymal transition (EMT) markers, angiogenic factors, and vasculogenic mimicry formation were evaluated using RT-qPCR and Western blot.

RESULTS

ETV4 was upregulated, while miR-29b expression was decreased in CRC tissues. ETV4 was identified as a target gene of miR-29b, which in turn inactivated the ERK signaling pathway by targeting ETV4 and inhibiting EGFR transcription. Transfection with miR-29b mimic, siRNA-ETV4, or ERK signaling pathway inhibitor U0126 increased expression of E-cadherin and TSP-1, and CRC cell apoptosis, yet reduced expression of ERK1/2, MMP-2, MMP-9, Vimentin, and VEGF, as well as inhibiting EMT, angiogenesis, and CRC cell migration and invasion. The EMT, angiogenesis and cancer progression induced by miR-29b inhibitor were reversed by siRNA-mediated ETV4 silencing.

CONCLUSIONS

miR-29b suppresses angiogenesis and EMT in CRC via the ETV4/ERK/EGFR axis.

Overexpression of PAX8-AS1 Inhibits Malignant Phenotypes of Papillary Thyroid Carcinoma Cells via miR-96-5p/PKN2 Axis

BACKGROUND

Thyroid carcinoma (THCA) is the most frequent endocrine malignancy. Papillary thyroid carcinoma (PTC) is the major subtype of THCA, accounting for over 80% of all THCA cases. LncRNA PAX8-AS1, a tumor suppressor associated with various human cancers, has been reported to be relevant to the regulation of all sorts of cellular processes. The purpose of this study was to verify the role of PAX8-AS1 in PTC.

METHODS

Three human PTC cell lines (K1, TPC-1, and IHH4) and one normal human thyroid cell line, Nthy-ori3-1, were used in our study. The expression of genes was detected by qRT-PCR. The bioinformatic analysis and luciferase reporter assay were used to confirm the binding relationship of PAX8-AS1 to miR-96-5p, and the targeting relationship of miR-96-5p to PKN2 was also predicted. Cell proliferation and apoptosis capacities were assessed by MTT and flow cytometry, respectively. EdU assay was used to detect cell proliferation. Western blot assay was employed to examine protein expression.

RESULTS

The expression of PAX8-AS1 was decreased in PTC tissues and cells. PAX8-AS1 overexpression inhibited the proliferation of PTC cells and promoted cell apoptosis. In addition, PAX8-AS1 bonds with miR-96-5p, whose downregulation elevated the expression of PKN2 in PTC cells. Importantly, according to the rescue experiments, PKN2 silencing partially reversed the inhibitory effects of PAX8-AS1 expression on PTC cell proliferation and apoptosis.

CONCLUSIONS

We found that the PAX8-AS1/miR-96-5p/PKN2 axis was closely related to the progression of PTC, which could be a potential target for treating PTC patients.

Dissecting miRNA signature in colorectal cancer progression and metastasis

Colorectal cancer (CRC) is the third most common cancer and leading cause of cancer related deaths worldwide. Despite recent advancements in surgical and molecular targeted therapies that improved the therapeutic efficacy in CRC, the 5 years survival rate of CRC patients still remains frustratingly poor. Accumulated evidences indicate that microRNAs (miRNAs) play a crucial role in the progression and metastasis of CRC. Dysregulated miRNAs are closely associated with cancerous phenotypes (e.g. enhanced proliferative and invasive ability, evasion of apoptosis, cell cycle aberration, and promotion of angiogenesis) by regulating their target genes. In this review, we provide an updated overview of tumor suppressive and oncogenic miRNAs, circulatory miRNAs, and the possible causes of dysregulated miRNAs in CRC. In addition, we discuss the important functions of miRNAs in drug resistance of CRC.

Molecular mechanisms underlying the enhancement of carbon ion beam radiosensitivity of osteosarcoma cells by miR-29b

Carbon ion radiotherapy (CIRT) is more effective than conventional photon beam radiotherapy in treating osteosarcoma (OSA); however, the outcomes of CIRT alone are still unsatisfactory. In this study, we aimed to investigate whether miR-29b acts as a radiosensitizer for CIRT. The OSA cell lines U2OS and KHOS were treated with carbon ion beam alone, γ-ray irradiation alone, or in combination with an miR-29b mimic. OSA cell death as well as invasive and migratory abilities were analyzed through viability, colony formation, Transwell, and apoptosis assays. miR-29 expression was downregulated in OSA tissues compared to that in normal tissues and was associated with metastasis and relapse in patients with OSA. Further, miR-29b was found to directly target the transcription factor Sp1 and suppress the activation of the phosphatase and tensin homolog (PTEN)-AKT pathway. Conversely, Sp1 was found to attenuate the inhibitory effects of miR-29b in OSA cells. When used in combination with miR-29b mimic, carbon ion beam markedly inhibited invasion, migration, and proliferation of OSA cells and promoted apoptosis by inhibiting AKT phosphorylation in a Sp1/PTEN-mediated manner. Taken together, miR-29b mimic improved the radiosensitivity of OSA cells via the PTEN-AKT-Sp1 signaling pathway, presenting a novel strategy for the development of carbon ion beam combination therapy.

miR-96-5p Suppresses the Progression of Nasopharyngeal Carcinoma by Targeting CDK1

Background

Nasopharyngeal carcinoma (NPC) is a malignant tumor that occurs in the nasopharyngeal mucosa. Clinically, radiotherapy is the preferred treatment for NPC, and cervical lymph node metastasis is easy to emerge in the early stage. Therefore, this study aimed to investigate the role and potential molecular mechanisms of miR-96-5p in NPC cells to develop new therapeutic horizons.

Methods

The expression of miR-96-5p and CDK1 was measured by RT-qPCR or Western blot. The target relationship between miR-96-5p and CDK1 was confirmed by luciferase reporter assay. CCK-8, sphere formation, flow cytometry and colony formation assay were employed to examine cell viability, stem-like property, apoptosis and cycle, respectively. Male BALB/c nude mice model (6-8 weeks, weigh 18-20 g) was used to evaluate the effect of miR-96-5p on tumor growth in vivo.

Results

miR-96-5p was lowly expressed and CDK1 was highly expressed in NPC tissues and cell lines. CDK1 was identified as a direct target of miR-96-5p, and its expression was negatively regulated by miR-96-5p. By targeting CDK1, miR-96-5p overexpression significantly inhibited tumor sphere formation, promoted apoptosis and cell cycle arrest in CNE-2Z cells. Importantly, CCK-8 and colony formation assay demonstrated that elevated miR-96-5p enhanced the radiotherapy and chemotherapy sensitivity of CNE-2Z cells. Animal experiments showed that the overexpression of miR-96-5p reduced tumor weight and size in tumor-bearing mice and inhibited the expression of stem-like marker proteins and apoptosis-related proteins.

Conclusion

These results, together, suggested that miR-96-5p induced cell cycle arrest and apoptosis, inhibited stem-like property, and enhanced the radiochemical sensitivity of NPC by targeting CDK1. In short, miR-96-5p may be a diagnostic and therapeutic target for NPC.

MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis

The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.

MiR-29b-3p Reverses Cisplatin Resistance by Targeting COL1A1 in Non-Small-Cell Lung Cancer A549/DDP Cells

Objective

To investigate the expression of miR-29b-3p in tissues and cells of non-small-cell lung cancer (NSCLC) and its effect on cisplatin resistance in NSCLC cells and its mechanism.

Methods

The mRNA expression of miR-29b-3p and COL1A1 in NSCLC tissue, cell line A549 and cisplatin-resistant cell line A549/DDP was detected by RT-qPCR. MiR-29b-3p Mimics was transfected into A549/DDP cells, and the cell viability, proliferation, apoptosis and related protein expression were detected by CCK-8, flow cytometry and Western blot. Also, luciferase reporter gene assay was used to verify the targeting relationship between miR-29b-3p and COL1A1. Moreover, COL1A1 overexpression lentivirus and miR-29b-3p mimics (Mimics+COL1A1) were simultaneously transfected into A549/DDP cells, and then the cell viability and related protein expression were measured.

Results

In NSCLC tissue and its cell line, miR-29b-3p was downregulated and COL1A1 was upregulated (P<0.05). After A549/DDP cell was transfected by mimics, its cell viability and proliferation rate decreased, apoptosis rate and the expression of tumor suppressor gene PTEN and apoptosis-related protein BAX were increased (P<0.05), which could be reversed by Mimics+COL1A1 co-transfection. Luciferase reporter gene assay indicated that COL1A1 was the target gene of miR-29b-3p.

Conclusion

All in all, miR-29b-3p can reverse the cisplatin resistance of A549/DDP cells by inhibiting the expression of COL1A1 gene and increasing the expression of PTEN and BAX.

Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis

The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.

microRNA-29b inhibits cell growth and promotes sensitivity to oxaliplatin in colon cancer by targeting FOLR1

The present study was aimed to explore the functional role of microRNA (miR)-29b in colon cancer, as well as underlying mechanisms. Expressions of miR-29b and folate receptor 1 (FOLR1) were measured in both human colon tumor samples and cell lines. Colon cancer cell lines SW480 and SW620 were transfected with miR-29b mimic, antisense oligonucleotides (ASO)-miR-29b, small interfering (siRNA) against FOLR1 (si-FOLR1), or corresponding negative controls (NCs), and then were incubated with or without oxaliplatin (L-OHP). Thereafter, cell viability, cytotoxicity, cell apoptosis, and expression of FOLR1, ATP Binding Cassette Subfamily G Member 2 (ABCG2) and p-glycoprotein (p-gp) were analyzed. We found that miR-29b was significantly decreased, while FOLR1 was statistically elevated in colon cancer samples and cell lines compared to the nontumor samples and nontumourigenic immortalized human colon epithelial cell line FHC. Overexpression of miR-29b markedly inhibited cell viability, promoted sensitivity to L-OHP, stimulated cell apoptosis (all p < .05), and decreased the levels of ABCG2 and p-gp in cancer cells, whereas suppression of miR-29b showed contrary results. Moreover, we observed that FOLR1 was a direct target of miR-29b and was negatively regulated by miR-29b. In addition, the findings revealed that the effects of FOLR1 inhibition on cell viability, sensitivity to L-OHP, cell apoptosis, and the levels of ABCG2 and p-gp were similar to overexpression of miR-29b. Taken together, our study suggests that miR-29b inhibits cell growth and promotes sensitivity to L-OHP in colon cancer by targeting FOLR1.

Focused screening reveals functional effects of microRNAs differentially expressed in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is still a leading cause of death worldwide. Recent studies have pointed to an important role of microRNAs in carcinogenesis. Several microRNAs are described as aberrantly expressed in CRC tissues and in the serum of patients. However, functional outcomes of microRNA aberrant expression still need to be explored at the cellular level. Here, we aimed to investigate the effects of microRNAs aberrantly expressed in CRC samples in the proliferation and cell death of a CRC cell line.

METHODS

We transfected 31 microRNA mimics into HCT116 cells. Total number of live propidium iodide negative (PI-) and dead (PI+) cells were measured 4 days post-transfection by using a high content screening (HCS) approach. HCS was further used to evaluate apoptosis (via Annexin V and PI staining), and to discern between intrinsic and extrinsic apoptotic pathways, by detecting cleaved Caspase 9 and 8, respectively. To reveal mRNA targets and potentially involved mechanisms, we performed microarray gene expression and functional pathway enrichment analysis. Quantitative PCR and western blot were used to validate potential mRNA targets.

RESULTS

Twenty microRNAs altered the proliferation of HCT116 cells in comparison to control. miR-22-3p, miR-24-3p, and miR-101-3p significantly repressed cell proliferation and induced cell death. Interestingly, all anti-proliferative microRNAs in our study had been previously described as poorly expressed in the CRC samples. Predicted miR-101-3p targets that were also downregulated by in our microarray were enriched for genes associated with Wnt and cancer pathways, including MCL-1, a member of the BCL-2 family, involved in apoptosis. Interestingly, miR-101-3p preferentially downregulated the long anti-apoptotic MCL-1 L isoform, and reduced cell survival specifically by activating the intrinsic apoptosis pathway. Moreover, miR-101-3p also downregulated IL6ST, STAT3A/B, and MYC mRNA levels, genes associated with stemness properties of CRC cells.

CONCLUSIONS

microRNAs upregulated in CRC tend to induce proliferation in vitro, whereas microRNAs poorly expressed in CRC halt proliferation and induce cell death. We provide novel evidence linking preferential inhibition of the anti-apoptotic MCL-1 L isoform by miR-101-3p and consequent activation of the intrinsic apoptotic pathway as potential mechanisms for its antitumoral activity, likely due to the inhibition of the IL-6/JAK/STAT signaling pathway.

MicroRNA-29b-3p suppresses oral squamous cell carcinoma cell migration and invasion via IL32/AKT signalling pathway

Oral squamous cell carcinoma (OSCC) is aggressive accompanied with poor prognosis. We previously isolated the most invasive cells resembling the invasive tumour front by microfluidic technology and explored their differentially expressed microRNAs (miRNAs) in our previous work. Here, we verified the miR‐29b‐3p as a guarder that suppressed migration and invasion of OSCC cells and was down‐regulated in the most invasive cells. Besides that, the invasion suppression role of miR‐29b‐3p was achieved through the IL32/AKT pathway. Thus, miR‐29b‐3p and IL32 might serve as therapeutic targets for blocking the progression and improving the outcome of OSCC.

Serum miR-29b as a novel biomarker for glioblastoma diagnosis and prognosis

Altered expression of serum microRNAs (miRNA) has been reported to correlate with carcinogenesis and progression of glioblastoma (GBM). This study assessed the potential diagnostic and prognostic value of serum miR-29b for GBM. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the expression levels of serum miR-29b in 107 patients with GBM patients, 40 patients with anaplastic astrocytoma (AA) and 80 healthy volunteers. The results showed that serum miR-29b levels were much lower in patients with GBM than in those with AA or healthy controls. Receiver operating characteristic (ROC) curve analysis revealed that serum exosomal miR-29b could effectively distinguish GBM patients from AA patients or normal controls. In addition, serum exosomal miR-29b level was significantly increased after treatment. Low serum exosomal miR-29b expression was strongly associated with aggressive clinical findings and shorter survival. Moreover, the Cox regression analysis demonstrated that serum exosomal miR-29b was an independent prognostic indicator. Collectively, serum exosomal miR-29b might be a promising biomarker for predicting prognosis of GBM.

High Tiam1 expression predicts positive lymphatic metastasis and worse survival in patients with malignant solid tumors: a systematic review and meta-analysis

Background

Many studies have explored the prognostic value of T-cell lymphoma invasion and metastasis inducing factor 1 (Tiam1) and its association with lymphatic metastasis in malignant solid tumors, but the conclusions remain controversial. Therefore, we performed a meta-analysis to systematically assess the prognostic value of Tiam1 expression and its association with lymphatic metastasis in malignant solid tumors.

Methods

We searched eligible studies in PubMed, Web of Science and EMBASE databases (from inception up to October 2018). The combined HR with 95% CI was used to estimate the prognostic value of Tiam1 expression. The correlation between Tiam1 expression and lymphatic metastasis was assessed using the combined odds ratio (OR) with 95% CI.

Results

A total of 17 studies with 2,228 patients with solid tumors were included in this meta-analysis. The overall estimated results showed that high Tiam1 expression was significantly associated with shorter overall survival (HR= 2.08, 95% CI: 1.62-2.68, P<0.01), and disease-free survival (HR = 1.86, 95% CI: 1.49-2.32, P<0.01). Besides, we also found that there was a close relationship between high Tiam1 expression and positive lymphatic metastasis (OR=2.63; 95% CI: 1.79-3.84, P<0.01).

Conclusion

High Tiam1 expression was significantly associated with shorter survival and positive lymphatic metastasis in patients with malignant solid tumors. Therefore, Tiam1 may be a promising prognostic biomarker and an effective therapeutic target for malignant solid tumors.

MicroRNA expression profiling in the colorectal normal-adenoma-carcinoma transition

Colorectal adenoma is a major precursor to colorectal cancer. Investigating the alteration of microRNA (miRNA/miR) expression during the progression from normal colorectal tissue to adenoma, and finally to colorectal carcinoma may aid our understanding of the biological mechanisms of colorectal tumorigenesis. In the present study, the miRNA expression profiles of normal colorectal tissue, adenoma and colorectal carcinoma from 6 patients were evaluated using miRNA-sequencing. A total of 334 miRNAs were identified as differentially expressed. It was revealed that 34 miRNAs were upregulated in all 6 patients, including miR-135b-5p, miR-18a-5p and miR-29b-3p, and 28 miRNAs were downregulated, including miR-1-3p, miR-338-3p and miR-218-5p. Using bioinformatic analysis, the potential target genes of these 62 miRNAs were predicted and found to be enriched in 'transcription, DNA-dependent (GO:0006351)', 'signal transduction (GO:0007165)', 'small molecule metabolic process (GO:0044281)' 'PI3K/AKT signaling pathway (path ID:04151)' and 'MAPK signaling pathway (path ID:04010)'. The miRNA expression profiles identified in the present study may extend our understanding of the molecular mechanisms underlying colorectal tumorigenesis and promote novel perspectives for prevention, diagnosis and treatment.

Downregulated microRNAs in the colorectal cancer: diagnostic and therapeutic perspectives

Colorectal cancer (CRC), the third most common cancer in the world, has no specific biomarkers that facilitate its diagnosis and subsequent treatment. The miRNAs, small single-stranded RNAs that repress the mRNA translation and trigger the mRNA degradation, show aberrant levels in the CRC, by which these molecules have been related with the initiation, progression, and drug-resistance of this cancer type. Numerous studies show the microRNAs influence the cellular mechanisms related to the cell cycle, differentiation, apoptosis, and migration of the cancer cells through the post-transcriptionally regulated gene expression. Specific patterns of the upregulated and down-regulated miRNA have been associated with the CRC diagnosis, prognosis, and therapeutic response. Concretely, the downregulated miRNAs represent attractive candidates, not only for the CRC diagnosis, but for the targeted therapies via the tumor-suppressing microRNA replacement. This review shows a general overview of the potential uses of the miRNAs in the CRC diagnosis, prognosis, and treatment with a special focus on the downregulated ones. [BMB Reports 2018; 51(11): 563-571].

TIAM1 promotes chemoresistance and tumor invasiveness in colorectal cancer

Accumulating evidence suggests that cancer cells with stem cell-like features have higher resistance to chemotherapeutic agents. Herein, we identified T-lymphoma invasion and metastasis-inducing protein-1 (TIAM1) as one of the Wnt-signaling associated genes which drives self-renewal and its expression is upregulated by cancer associated fibroblasts (CAFs). TIAM1 expression was assessed in resected colorectal cancer (CRC) tissues from 300 patients who did or did not respond to chemotherapy. siRNA and CRISPR/Cas9 was used to examine whether the inhibition of TIAM1 affects chemosensitivity of CRC. We demonstrate that stemness through Wnt signaling regulates chemosensitivity and this phenomenon occurs exclusively in cancer stem cells. Subsequently, we established patient-derived CAFs and tested whether the drug sensitivity of CRC cell lines is altered with CAF-derived conditioned medium. High-TIAM1 expression correlated significantly with poor prognosis of CRC patients, and was overexpressed in patients who did not respond to chemotherapy. We demonstrated that the inhibition of TIAM1 enhanced sensitivity to chemotherapeutic drugs and reduced tumor invasiveness in a series of experiments in vitro. Moreover, CAF-derived conditioned media increased stemness and chemoresistance in CRC cell lines through TIAM1 overexpression. In addition, we validated TIAM1 associated drug sensitivity using a xenograft model. We have demonstrated that TIAM1 is overexpressed in CRC tumors from patients who did not respond to chemotherapeutic drugs and levels of TIAM1 expression served as an independent prognostic factor. Mechanistically, CAFs enhanced CRC chemoresistance through TIAM1 overexpression. Collectively, these results suggest that TIAM1 regulates chemosensitivity in tumors and stroma and thus may be an attractive therapeutic target.

MYH9 Promotes Growth and Metastasis via Activation of MAPK/AKT Signaling in Colorectal Cancer

The contractile protein MYH9 (non-muscle myosin IIA) is an actin-binding protein that plays a fundamental role in cell adhesion, migration, and division. However, its distinct role in colorectal cancer (CRC) still remains unidentified. In this study, we detected significant MYH9 overexpression in CRC samples compared with paired normal tissues using western blotting and tissue microarray immunohistochemistry (IHC). Moreover, analysis of patient clinical information demonstrated that MYH9 overexpression was strongly correlated with lymph node metastasis and poor overall survival. Endogenous overexpression of MYH9 enhanced the ability of cell proliferation and migration in vitro, and accelerated CRC growth in mouse models. Silencing of MYH9 revealed repressive effects on CRC cells in vitro and in vivo. Furthermore, primary biomechanics that involved MAPK/AKT signaling mediated epithelial-mesenchymal transition (EMT) was uncovered underlying MYH9 dependent cell behaviors. Collectively, our data showed that MYH9 significantly promoted tumorigenesis by regulating MAPK/AKT signaling, and was remarkably correlated with poor prognosis in CRC. MYH9 may thus be a novel biomarker and drug target in the diagnosis and treatment of CRC.

miRNA Regulation of the Hyperproliferative Phenotype of Vascular Smooth Muscle Cells in Diabetes

Harnessing the mechanisms underlying the exacerbated vascular remodeling in diabetes mellitus (DM) is pivotal to prevent the high toll of vascular diseases in patients with DM. miRNA regulates vascular smooth muscle cell (VSMC) phenotypic switch. However, miRNA modulation of the detrimental diabetic VSMC phenotype is underexplored. Streptozotocin-induced type 1 DM (T1DM) Wistar rats and type 2 DM (T2DM) Zucker rats underwent right carotid artery experimental angioplasty, and global miRNA/mRNA expression profiling was obtained by RNA sequencing (RNA-Seq). Two days after injury, a set of six miRNAs were found to be uniquely downregulated or upregulated in VSMCs both in T1DM and T2DM. Among these miRNAs, miR-29c and miR-204 were the most significantly misregulated in atherosclerotic plaques from patients with DM. miR-29c overexpression and miR-204 inhibition per se attenuated VSMC phenotypic switch in DM. Concomitant miR-29c overexpression and miR-204 inhibition fostered an additive reduction in VSMC proliferation. Epithelial membrane protein 2 (Emp2) and Caveolin-1 (Cav1) mRNAs were identified as direct targets of miR-29c and miR-204, respectively. Importantly, contemporary miR-29c overexpression and miR-204 inhibition in the injured artery robustly reduced arterial stenosis in DM rats. Thus, contemporaneous miR-29c activation and miR-204 inhibition in DM arterial tissues is necessary and sufficient to prevent the exaggerated VSMC growth upon injury.

AngiomiRs: MicroRNAs driving angiogenesis in cancer (Review)

Angiogenesis is an important hallmark of cancer serving a key role in tumor growth and metastasis. Therefore, tumor angiogenesis has become an attractive target for development of novel drug therapies. An increased amount of anti‑angiogenic compounds is currently in preclinical and clinical development for personalized therapies. However, resistance to current angiogenesis inhibitors is emerging, indicating that there is a need to identify novel anti‑angiogenic agents. In the last decade, the field of microRNA biology has exploded revealing unsuspected functions in tumor angiogenesis. These small non‑coding RNAs, which have been dubbed as angiomiRs, may target regulatory molecules driving angiogenesis, such as cytokines, metalloproteinases and growth factors, including vascular endothelial growth factor, platelet‑derived growth factor, fibroblast growth factor, epidermal growth factor, hypoxia inducible factor‑1, as well as mitogen‑activated protein kinase, phosphoinositide 3‑kinase and transforming growth factor signaling pathways. The present review discusses the current progress towards understanding the functions of miRNAs in tumor angiogenesis regulation in diverse types of human cancer. Furthermore, the potential clinical application of angiomiRs towards anti‑angiogenic tumor therapy was explored.

MicroRNA-488 inhibits progression of colorectal cancer via inhibition of the mitogen-activated protein kinase pathway by targeting claudin-2

Colorectal cancer (CRC) affects people globally, and lymph node metastasis (LNM) is an important indicator of poor clinical outcome in CRC. The current study aims to evaluate the role of microRNA-448 (miR-488) and claudin-2 (CLDN2) in epithelial-mesenchymal transition (EMT) and LNM of CRC through the MAPK signaling pathway. First, microarray analysis indicated that miR-488 was poorly expressed in CRC, whereas CLDN2 was highly expressed. Additionally, the bioinformatics website MicroRNA.org and the dual luciferase reporter gene assay found that CLDN2 was a target gene of miR-488. Next, the results for the correlations between expression of miR-488 and clinicopathological characteristics of CRC indicated that the expression of miR-488 was closely associated with differentiation degree, LNM, and Dukes stages in CRC patients. Moreover, overexpression of miR-488 inhibited the activation of the MAPK signal transduction pathway. Notably, loss- and gain-of-function experiments demonstrated that upregulation of miR-488 suppressed SW480 cell viability, invasion, and migration and promoted apoptosis in SW480 cells. Finally, overexpression of miR-488 inhibited LNM, microlymphatic vessel density, and tumor growth in nude mice. We conclude that overexpression of miR-488 could suppress the cell proliferation, EMT, and LNM of CRC cells via inhibition of the CLDN2-mediated MAPK signaling pathway, which could be a new molecular therapy target for CRC.

Expression and prognostic value of miRNA-29b in peripheral blood for endometrial cancer

AIM

We explored the role of miR-29b expression in endometrial cancer (EC) progression and patient prognosis.

MATERIALS & METHODS

Patients with primary or metastatic EC (n = 356), patients with endometrial benign tumors (n = 149) and healthy female subjects (n = 155) were collected. We assessed the diagnostic value of miR-29b expression for EC using a receiver operating characteristic curve.

RESULTS

The miR-29b expressions were lower in patients with primary or metastatic EC. Using miR-29b expression to diagnose EC produced 0.976 area under the curve, 96.1% sensitivity and 97.9% specificity. Cox proportional hazard regression model verified a low miR-29b expression and is an unfavorable prognostic indicator for EC.

CONCLUSION

We conclude that downregulated miR-29b expression correlates with poor EC prognosis and is helpful to evaluate the EC prognosis.

Identification of miR-29b targets using 3-cyanovinylcarbazole containing mimics

MicroRNAs (miRNAs) are highly conserved ∼22 nt small noncoding RNAs that bind partially complementary sequences in target transcripts. MicroRNAs regulate both translation and transcript stability, and play important roles in development, cellular homeostasis, and disease. There are limited approaches available to agnostically identify microRNA targets transcriptome-wide, and methods using miRNA mimics, which in principle identify direct miRNA:transcript pairs, have low sensitivity and specificity. Here, we describe a novel method to identify microRNA targets using miR-29b mimics containing 3-cyanovinylcarbazole (CNVK), a photolabile nucleoside analog. We demonstrate that biotin-tagged, CNVK-containing miR-29b (CNVK-miR-29b) mimics are nontoxic in cell culture, associate with endogenous mammalian Argonaute2, are sensitive for known targets and recapitulate endogenous transcript destabilization. Partnering CNVK-miR-29b with ultra-low-input RNA sequencing, we recover ∼40% of known miR-29b targets and find conservation of the focal adhesion and apoptotic target pathways in mouse and human. We also identify hundreds of novel targets, including NRAS, HOXA10, and KLF11, with a validation rate of 71% for a subset of 73 novel target transcripts interrogated using a high-throughput luciferase assay. Consistent with previous reports, we show that both endogenous miR-29b and CNVK-miR-29b are trafficked to the nucleus, but find no evidence of nuclear-specific miR-29b transcript binding. This may indicate that miR-29b nuclear sequestration is a regulatory mechanism in itself. We suggest that CNVK-containing small RNA mimics may find applicability in other experimental models.

Down-regulation of miR-29b in carcinoma associated fibroblasts promotes cell growth and metastasis of breast cancer

Carcinoma associated fibroblasts (CAFs) play important roles in breast cancer development and progression. Recent studies show that microRNAs (miRNAs) are the main regulators in CAFs. MiR-29b is one of the significant down-regulated miRNAs in CAFs from the miRNA screening. The role of miR-29b in the interaction between CAFs and breast cancer is still unclear. In the present study, we investigated the effects of CAFs on breast cancer cell proliferation and metastasis regulated by miR-29b. We found that fibroblasts activated by co-cultured breast cancer cells produced higher levels of some chemokines like CCL11, CXCL14, which accelerated breast cancer cell growth and induced drug resistance and metastasis. Increased miR-29b expression in activated fibroblasts could suppress the activating p38-STAT1 signal pathway in breast cancer cells. We also found that the expression of CCL11 and CXCL14 could be regulated by miR-29b in CAFs. Our results illustrate that down-regulation of miR-29b in CAFs plays an important role in tumor stroma by activating p38-STAT1 in breast cancer cells. The study indicates that cancer cells and fibroblasts interaction promotes breast cancer cell growth, drug resistance, migration and invasion due to the lack of miR-29b expression in CAFs.

Suppressive role exerted by microRNA-29b-1-5p in triple negative breast cancer through SPIN1 regulation

MiR-29 family dysregulation occurs in various cancers including breast cancers. We investigated miR-29b-1 functional role in human triple negative breast cancer (TNBC) the most aggressive breast cancer subtype. We found that miR-29b-1-5p was downregulated in human TNBC tissues and cell lines. To assess whether miR-29b-1-5p correlated with TNBC regenerative potential, we evaluated cancer stem cell enrichment in our TNBC cell lines, and found that only MDA-MB-231 and BT-20 produced primary, secondary and tertiary mammospheres, which were progressively enriched in OCT4, NANOG and SOX2 stemness genes. MiR-29b-1-5p expression inversely correlated with mammosphere stemness potential, and miR-29b-1 ectopic overexpression decreased TNBC cell growth, self-renewal, migration, invasiveness and paclitaxel resistance repressing WNT/βcatenin and AKT signaling pathways and stemness regulators. We identified SPINDLIN1 (SPIN1) among predicted miR-29b-1-5p targets. Consistently, SPIN1 was overexpressed in most TNBC tissues and cell lines and negatively correlated with miR-29b-1-5p. Target site inhibition showed that SPIN1 seems to be directly controlled by miR-29b-1-5p. Silencing SPIN1 mirrored the effects triggered by miR-29b-1 overexpression, whereas SPIN1 rescue by SPIN1miScript protector, determined the reversal of the molecular effects produced by the mimic-miR-29b-1-5p. Overall, we show that miR-29b-1 deregulation impacts on multiple oncogenic features of TNBC cells and their renewal potential, acting, at least partly, through SPIN1, and suggest that both these factors should be evaluated as new possible therapeutic targets against TNBC.

Regulation of EMT in Colorectal Cancer: A Culprit in Metastasis

Epithelial to mesenchymal transition (EMT) is a process during which cells lose their epithelial characteristics, for instance cell polarity and cell-cell contact, and gain mesenchymal properties, such as increased motility. In colorectal cancer (CRC), EMT is associated with an invasive or metastatic phenotype. In this review, we discuss recent studies exploring novel regulation mechanisms of EMT in CRC, including the identification of new CRC EMT regulators. Upregulation of inducers can promote EMT, leading to increased invasiveness and metastasis in CRC. These inducers can downregulate E-cadherin and upregulate N-cadherin and vimentin (VIM) through modulating EMT-related signaling pathways, for instance WNT/β-catenin and TGF-β, and EMT transcription factors, such as zinc finger E-box binding homeobox 1 (ZEB1) and ZEB2. In addition, several microRNAs (miRNAs), including members of the miR-34 and miR-200 families, are found to target mRNAs of EMT-transcription factors, for example ZEB1, ZEB2, or SNAIL. Downregulation of these miRNAs is associated with distant metastasis and advanced stage tumors. Furthermore, the role of EMT in circulating tumor cells (CTCs) is also discussed. Mesenchymal markers on the surface of EMT CTCs were found to be associated with metastasis and could serve as potential biomarkers for metastasis. Altogether, these studies indicate that EMT is orchestrated by a complicated network, involving regulators of different signaling pathways. Further studies are required to understand the mechanisms underlying EMT in CRC.

MicroRNAs in the etiology of colorectal cancer: pathways and clinical implications

MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present in the human genome, ∼250 miRNAs are reported to have changes in abundance or altered functions in colorectal cancer. Thousands of studies have documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their frequent participation in feedback loops, which probably serve to reinforce or magnify biological outcomes to manifest a particular cellular phenotype. Here, we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs (anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability in patient-derived samples and ease of detection with standard and novel techniques, we also discuss the potential use of miRNAs as biomarkers in the diagnosis of colorectal cancer and as prognostic indicators of this disease. MiRNAs also represent attractive candidates for targeted therapies because their function can be manipulated through the use of synthetic antagonists and miRNA mimics.

Summary: This Review provides an overview of some important microRNAs and their roles in colorectal cancer.

MiR-29b/TET1/ZEB2 signaling axis regulates metastatic properties and epithelial-mesenchymal transition in breast cancer cells

MiR-29b has been reported to be both a suppressor and a promoter in breast cancer (BC) cells proliferation and metastasis. Significant efforts have been made to explain the seemingly contradictory effects of miR-29b on BC, but no answer has yet been clearly verified. In this study, we overexpressed and knocked down miR-29b in BC cell lines, modulated expression of its downstream target gene TET1 and downregulated a downstream target gene of TET1, ZEB2, to explore the regulatory mechanism of miR-29b in BC cell proliferation, migration and epithelial-mesenchymal transition (EMT). Our results showed lower expression of miR-29b in BC samples and cell lines. Functional assays showed that miR-29b overexpression resulted in a higher cell proliferation, greater colony formation, higher migration rate and EMT. A dual luciferase assay identified TET1 as a direct target of miR-29b. As the promoting effects of miR-29b in the proliferation and metastasis of MDA-MB-231 and MCF-7, knockdown of TET1 also led to increased proliferation, colony formation, invasion and EMT. Further, we found that TET1 bound to the promoter of ZEB2, and siTET1 enhanced ZEB2 expression. Disruption of ZEB2 expression inhibited BC cells proliferation, colony formation and invasion. Our results establish the miR-29b/TET1/ZEB2 pathway in BC cell proliferation, migration and provide a theoretical basis for further research on the molecular mechanisms and new clinical treatments for BC.

Restoration of miR-29b exerts anti-cancer effects on glioblastoma

Background

Glioblastoma multiforme (GBM) is known as one of the most fatal forms of cancer. MicroRNAs have been widely implicated in the regulation of mammalian development and pathogenesis. The brain-enriched miR-29 subfamilies are known to be exclusively expressed in the developing brain, and they are aberrantly down-regulated in GBM. This study aims to elucidate the role of miR-29b in GBM development and the feasibility of therapeutic targeting using conjugated nanoparticles.

Methods

After confirmation of miR-29b expression levels in GBM tissues by analysis of open source data, the anticancer effect of miR-29b was tested by the introduction of syn-hsa-miR-29b-3p in the A172 GBM cell line. In vitro studies of cell viability and apoptosis and ex vivo study using GBM tissue slice cultures from 3 patients and nanoparticle delivery of miR-29b were performed.

Results

We discovered an increase in apoptotic cell populations with the introduction of miR-29b in the GBM cell line. An established human-derived GBM tissue slice culture system confirmed the anticancer effect of miR-29b-conjugated nanoparticles. Using PCR array, we found that exogenous miR-29b inhibits the expression of COL1A2, COL3A1, COL4A1, ELN, ITGA11, MMP24, and SPARC, which mediates an anticancer effect.

Conclusions

miR-29b may serve as a putative therapeutic molecule when its expression is restored using a nanoparticle delivery system in GBM.

Long non-coding RNA CHCHD4P4 promotes epithelial-mesenchymal transition and inhibits cell proliferation in calcium oxalate-induced kidney damage

Kidney stone disease is a major cause of chronic renal insufficiency. The role of long non-coding RNAs (lncRNAs) in calcium oxalate-induced kidney damage is unclear. Therefore, we aimed to explore the roles of lncRNAs in glyoxylate-exposed and healthy mouse kidneys using microarray technology and bioinformatics analyses. A total 376 mouse lncRNAs were differentially expressed between the two groups. Using BLAST, 15 lncRNA homologs, including AU015836 and CHCHD4P4, were identified in mice and humans. The AU015836 expression in mice exposed to glyoxylate and the CHCHD4P4 expression in human proximal tubular epithelial (HK-2) cells exposed to calcium oxalate monohydrate were analyzed, and both lncRNAs were found to be upregulated in response to calcium oxalate. To further evaluate the effects of CHCHD4P4 on the cell behavior, we constructed stable CHCHD4P4-overexpressing and CHCHD4P4-knockdown HK-2 cells. The results showed that CHCHD4P4 inhibited cell proliferation and promoted the epithelial-mesenchymal transition in kidney damage and fibrosis caused by calcium oxalate crystallization and deposition. The silencing of CHCHD4P4 reduced the kidney damage and fibrosis and may thus be a potential molecular target for the treatment of kidney stones.

Mesenchymal stem cells correct impaired diabetic wound healing by decreasing ECM proteolysis

Impaired diabetic wound healing is associated with a dermal extracellular matrix protein profile favoring proteolysis; within the healing diabetic wound, this is represented by an increase in activated matrix metalloproteinase (MMPs). Treatment of diabetic wounds with mesenchymal stem cells (MSCs) has been shown to improve wound healing; however, there has not yet been an assessment of their ability to correct dysregulation of MMPs in diabetic wounds. Furthermore, there has been no prior assessment of the role of microRNA29b (miR-29b), an inhibitory regulatory molecule that targets MMP-9 mRNA. Using in vitro models of fibroblast coculture with MSCs and in vivo murine wound healing models, we tested the hypothesis that MSCs correct dysregulation of MMPs in a microRNA-29b-dependent mechanism. In this study, we first demonstrated that collagen I and III protein content is significantly reduced in diabetic wounds, and treatment with MSCs significantly improves collagen I content in both nondiabetic and diabetic wounds. We then found that MMP-9 gene expression and protein content were significantly upregulated in diabetic wounds, indicating elevated proteolysis. Treatment with MSCs resulted in a decrease in MMP-9 gene expression and protein content level in diabetic wounds 3 and 7 days after wounding. Zymographic analysis indicated that MSC treatment also decreased the amount of activated MMP-9 present in diabetic wounds. Furthermore, miR-29b expression was inversely associated with MMP-9 gene expression; miR-29b expression was decreased in diabetic wounds and diabetic fibroblast. Following treatment of diabetic wounds with MSCs, as well as in diabetic fibroblasts cocultured with MSCs, miR-29b was significantly increased. These findings suggest a potential mechanism through which MSCs enhance diabetic wound healing by improving collagen I content in diabetic wounds through decreasing MMP-9 expression and increasing miR-29b expression.

LASP2 suppresses colorectal cancer progression through JNK/p38 MAPK pathway meditated epithelial-mesenchymal transition

BACKGROUND

LASP2 (LIM and SH3 Protein 2) is a small focal adhesion protein belongs to nebulin protein family. As the newest member of nebulette family, the function of LASP2 remains to be identified.

METHODS

The relationship between LASP2 expression and clinical characteristics of CRC was analyzed in 89 paraffin-embedded archived CRC specimens by immunohistochemistry (IHC). The effects of LASP2 on cell growth and migration were examined in vitro, using CCK-8 and transwell assays. Western blotting was performed to examine the impact of LASP2 on the SAPK/JNK and MAPK signaling pathways.

RESULTS

In the present study, we observed a decreased LASP2 expression in clinical colorectal cancer samples compared with paired normal tissues. A negative correlation was also found between LASP2 and poor prognosis of CRC patients. Gain- and loss-of-function approaches revealed that LASP2 plays inhibitory effects on the growth and migration of human CRC cells in vitro. Western-blot results showed that LASP2 could attenuate epithelial-mesenchymal transition (EMT) to accomplish its suppression on CRC aggression. In LASP2 knocked down CRC cells, EMT was inhibited along with the inactivation of JNK/p38 MAPK pathway. Consistently, treatment of JNK inhibitor (JNK inhibitor II) together with p38 inhibitor (SB203580) could resume the process of EMT. Interestingly, we found a negative relationship between LASP2 and LASP1 expression in both CRC cell lines and tumors tissues, which suggests their converse function in CRC progression.

CONCLUSIONS

All the findings indicated that LASP2 may play a significant role in suppressing CRC progression and provided a novel biomarker for CRC therapy.

MicroRNAs: Potential candidates for diagnosis and treatment of colorectal cancer

Colorectal cancer (CRC) is known as the third common cancer worldwide and an important public health problem in different populations. Several genetics and environmental risk factors are involved in the development and progression of CRC including chromosomal abnormalities, epigenetic alterations, and unhealthy lifestyle. Identification of risk factors and biomarkers could lead to a better understanding of molecular pathways involved in CRC pathogenesis. MicroRNAs (miRNAs) are important regulatory molecules which could affect a variety of cellular and molecular targets in CRC. A large number of studies have indicated deregulations of some known tissue-specific miRNAs, for example, miR-21, miR-9, miR-155, miR-17, miR-19, let-7, and miR-24 as well as circulating miRNAs, for example, miR-181b, miR-21, miR-183, let-7g, miR-17, and miR-126, in patients with CRC. In the current review, we focus on the findings of preclinical and clinical studies performed on tissue-specific and circulating miRNAs as diagnostic biomarkers and therapeutic targets for the detection of patients at various stages of CRC.