MicroRNA-200b Stimulates Tumour Growth in TGFBR2-Null Colorectal Cancers by Negatively Regulating p27/kip1

Human umbilical cord mesenchymal stem cell-derived exosomes promote microcirculation in aged diabetic mice by TGF-β1 signaling pathway

BACKGROUND

Microvascular dysfunction is one of the most common pathological characteristics in Type 2 diabetes. Human mesenchymal stem cell-derived exosomes (hUCMSCs-Exo) have diverse functions in improving microcirculation; however, the molecular mechanism of hUCMSCs-Exo in regulating burn-induced inflammation is not well understood.

METHODS

hUCMSCs-Exo were extracted by hypervelocity centrifugation method, and exosome morphology was observed by transmission electron microscopy, exosome diameter distribution was detected by particle size analysis, and exosome specific proteins were identified by Western blot.2. DB/DB mice were randomly divided into exosomes group and PBS group. Exosomes and PBS were injected into the tail vein, respectively, and the calf muscle tissue was taken 28 days later. 0.5% Evans blue fluorescence assessment microvascular permeability. The expression of CD31 was detected by immunofluorescence.The morphology and function of microvessels in muscle tissue of lower limbs was evaluated by transmission electron microscopy.3. TMT proteomics was used to detect the changes of differential protein expression in lower limb muscle tissues of the PBS group and the exosome group, and data analysis was performed to screen key signal molecules and their involved biological pathways. Key signal molecules CD105 were verified by Western blot. The expression of TGF-β1 in exosomes were evaluated by Western blot.

RESULTS

Electron microscopy showed that hUCMSCs-Exo presented a uniform vesicle structure, and NTA showed that its diameter was about 160 nm. Western blot showed positive expression of specific proteins CD9, CD81 and TSG101 on exosomes.2. There is no significant change in blood glucose and body weight before and after the exosome treatment. The exosome group can significantly reduce the exudation of Evans blue. Compared with the PBS group. Meanwhile, CD31 immunofluorescence showed that the red fluorescence of exosome treatment was significantly increased, which was higher than that of PBS group. Transmission electron microscopy showed smooth capillary lumen and smooth and complete surface of endothelial cells in the exosome group, while narrow capillary lumen and fingerlike protrusion of endothelial cells in the PBS group.3.Quantitative analysis of TMT proteomics showed that there were 82 differential proteins, including 49 down-regulated proteins and 33 up-regulated proteins. Go enrichment analysis showed that the differential proteins were involved in molecular function, biological process, cell components,among which CD105 was one of the up-regulated proteins. Through literature search, CD105 was found to be related to endothelial cell proliferation. Therefore, this study verified the changes of CD105 in the exosome group, and it was used as the mechanism study of this study. 4. Western blot analysis showed that the expression of CD105 protein in lower limb muscle tissue of exosome group was significantly increased compared with that of PBS group. Based on the fact that CD105 is a component of the TGF-β1 receptor complex and exosomes are rich in growth factors and cytokines, this study further examined the expression of TGF-β1 in exosomes, and the results showed that exosomes had high expression of TGF-β1.

CONCLUSION

By improving the integrity of microvascular endothelial cells, hUCMSCs-Exo can improve the permeability of microvessels in diabetic lower muscle tissue, further promote the proliferation of lower limb muscle cells and inhibit the apoptosis of tissue cells. The mechanism may be associated with exosomes rich in TGF-β1, which is likely to promote endothelial cell proliferation and improve permeability through binding to the endothelial CD105/TβR-II receptor complex, while promoting angiogenesis and protecting skeletal muscle cells from apoptosis.

miR-200b, ZEB2 and PTPN13 Are Downregulated in Colorectal Carcinoma with Serosal Invasion

Serosal invasion is an independent negative prognostic factor in certain cancers, including CRC. However, the mechanisms behind serosal invasion are poorly understood. We therefore assumed that epithelial-mesenchymal transition (EMT) might be involved. Our study included 34 patients with CRC, 3 stage pT2, 14 stage pT3 and 17 showing serosal invasion (stage pT4a according to TNM staging system). RNA isolated from formalin-fixed paraffin-embedded tissue samples was analysed for expression of the miR-200 family and their target genes CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2 using real-time PCR. We found upregulation of miR-200b and ONECUT2 in CRC pT3 and pT4a compared to normal mucosa, and downregulation of CDKN1B in CRC pT3. Moreover, we observed, downregulation of miR-200b, PTPN13 and ZEB2 in CRC with serosal invasion (pT4a) compared to pT3. Our results suggest the involvement of partial EMT in serosal invasion of CRC. In addition, PTPN13 seems to be one of the important regulators involved in serosal invasion, and ONECUT2 in tumour growth.

MicroRNA-200b Regulates the Proliferation and Differentiation of Ovine Preadipocytes by Targeting p27 and KLF9

Simple Summary

The miR-200b has been shown to play an important role in preadipocyte proliferation and differentiation. Herein, we explored the role of miR-200b in ovine adipocyte development, using Oil Red O staining, cell viability analysis, EdU and RT-qPCR. The results showed that miR-200b facilitated proliferation and suppressed the differentiation of preadipocytes. The dual fluorescent reporter vector experiments showed that miR-200b directly targeted p27 and KLF9. Meanwhile, we demonstrated that p27 significantly inhibited the proliferation, while KLF9 significantly promoted the differentiation of preadipocytes.

Abstract

MicroRNAs (miRNAs) are crucial regulatory molecules in lipid deposition and metabolism. However, the effect of miR-200b on the regulation of proliferation and adipogenesis of ovine preadipocytes is unknown in the sheep (Ovis aries). In this study, the expression profiles of miR-200b were investigated in the seven tissues of Tibetan ewes and differentiated preadipocytes. The effect of miR-200b, as well as its target genes p27 and KLF9, on the proliferation of ovine preadipocytes and adipogenesis was also investigated, using cell viability analysis, EdU staining, Oil Red O staining and reverse transcription-quantitative PCR (RT-qRCR). The miR-200b was expressed in all the tissues investigated, and it was highly expressed in lung, liver, subcutaneous adipose and spleen tissues. The expression of miR-200b continuously decreased when the differentiation of ovine preadipocytes initiated. The miR-200b mimic dramatically accelerated the proliferation but inhibited differentiation of ovine preadipocytes. The miR-200b inhibitor resulted in an opposite effect on the proliferation and differentiation of ovine preadipocytes. The dual luciferase reporter assay results showed that miR-200b mimic significantly decreased the luciferase activity of p27 and KLF9 in HEK293 cells transfected with wild-type dual luciferase reporter vectors. This suggests that p27 and KLF9 are the target genes of miR-200b. In over-expressed-p27 preadipocytes, the number of EdU-labeled preadipocytes and the expression levels of proliferation marker genes CDK2, CDK4, CCND1 and PCNA significantly decreased. In addition, the transfection of over-expressed-KLF9 vector into adipocytes remarkably increased the accumulation of lipid droplets and the expression levels of differentiation marker genes aP2, PPARγ, LPL and GLUT4. These results suggest that miR-200b accelerated the proliferation but inhibited the adipogenic differentiation of ovine preadipocytes by targeting p27 and KLF9, respectively.

miR‑200b upregulation promotes migration of BEAS‑2B cells following long‑term exposure to cigarette smoke by targeting ETS1

Cigarette smoking is the leading cause of all histological types of lung cancer, and the role that microRNAs (miRNAs) serve in its pathogenesis is being increasingly recognized. The aim of the present study was to investigate the role of miR‑200b on migration in cigarette smoke‑induced malignant transformed cells. In the present study, miR‑200b expression was found to be increased in cigarette smoke (CS)‑exposed BEAS‑2B cells, lung cancer cell lines and tumor tissue samples. Using wound healing and Transwell migration assays, the migratory ability was shown to be increased in miR‑200b‑overexpressing cells, whereas miR‑200b knockdown resulted in reduced migration. Additionally, the expression of E‑Cadherin was downregulated, whereas that of N‑Cadherin was upregulated in miR‑200b mimic‑transfected cells, suggesting an increase in epithelial‑mesenchymal transition. Downstream, using four target gene prediction tools, six target genes of miR‑200b were predicted, amongst which, ETS proto‑oncogene 1 transcription factor (ETS1) was shown to be significantly associated with tumor invasion depth and negatively associated with miR‑200b expression. The interaction between miR‑200b and ETS1 was confirmed using a dual‑luciferase reporter assay. Using rescue experiments, the increased migratory ability of the miR‑200b‑overexpressing cells was reversed by ETS1 overexpression. In summary, this study showed that miR‑200b overexpression serves a carcinogenic role and promotes the migration of BEAS‑2B cells following long‑term exposure to CS by targeting ETS1.

Epithelial-Mesenchymal Transition in Colorectal Carcinoma: Comparison Between Primary Tumor, Lymph Node and Liver Metastases

There is emerging evidence suggesting that epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) play an important role in colorectal carcinoma (CRC), but their exact role remains controversial. Our aim was to analyze the miR-200 family as EMT markers and their target genes expression at invasive tumor front and in nodal and liver metastases. Sixty-three formalin-fixed paraffin-embedded tissue samples from 19 patients with CRC were included. Using a micropuncture technique, tissue was obtained from central part and invasive front of the primary tumor, and nodal and liver metastases. Expression of the miR-200 family and their target genes CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2 was analyzed using real-time PCR. We found miR-200 family down-regulation at invasive front compared to central part, and up-regulation of miRNA-200a/b/c and miR-429 in metastases compared to invasive front. At invasive front, TGFB2 was the only gene with inverse expression to the miR-200 family, whereas in metastases inverse expression was found for ONECUT2 and SOX2. CDKN1B, PTPN13 and ZEB2 were down-regulated at invasive front and up-regulated in metastases. Our results suggest the involvement of partial EMT at invasive tumor front, and partial MET in metastases in CRC, based on miR-200 family and its target genes expression.

HLJ2 Effectively Ameliorates Colitis-Associated Cancer via Inhibition of NF-κB and Epithelial-Mesenchymal Transition

Introduction

Colitis-associated cancer (CAC) accounts for approximately 15% of IBD patient mortalities. However, currently available anti-CAC drugs possess many disadvantages including safety, specificity and side effects. Therefore, the development of novel anti-CAC compounds is imperative. HLJ2 was a monomeric compound synthesized by our institute and reported to have an effect on ulcer colitis.

Methods

In vivo the AOM/DSS-induced CAC model was used to evaluate the effects of HLJ2 on ameliorating CAC symptoms, immunohistochemical analysis was used to analyze the pathological damage to colons and epithelial–mesenchymal transition was for changes of cytokines. In vitro, flow cytometric analysis, immunofluorescence and Western blot were used to detect the inhibition effect of HLJ2 on nuclear factor-κB and epithelial–mesenchymal transition in TGF-β1-stimulated SW480 cells.

Results

In the AOM/DSS animal model, HLJ2 was demonstrated to inhibit the secretion of inflammatory cytokines and nuclear factor-κB, levels of tumorigenesis-related proteins including snail, and finally inhibited a key step in metastasis, epithelial–mesenchymal transition. In vitro, HLJ2 was also shown to inhibit nuclear factor-κB and epithelial–mesenchymal transition in TGF-β1-stimulated SW480 cells in accordance with in vivo results. Meanwhile, the nuclear factor-κB inhibitor could interrupt the effect of HLJ2 on epithelial–mesenchymal transition.

Discussion

HLJ2 may ameliorate CAC through inhibiting nuclear factor-κB and then downstream epithelial–mesenchymal transition. The combination of the obvious improvement in effects on CAC without obvious side effects suggests that HLJ2 could be developed as a potential CAC therapeutic candidate.

Expression profiling of human milk derived exosomal microRNAs and their targets in HIV-1 infected mothers

Despite the use of antiretroviral therapy (ART) in HIV-1 infected mothers approximately 5% of new HIV-1 infections still occur in breastfed infants annually, which warrants for the development of novel strategies to prevent new HIV-1 infections in infants. Human milk (HM) exosomes are highly enriched in microRNAs (miRNAs), which play an important role in neonatal immunity. Furthermore, HM exosomes from healthy donors are known to inhibit HIV-1 infection and transmission; however, the effect of HIV-1 on HM exosomal miRNA signatures remains unknown. In this study, we used nCounter NanoString technology and investigated miRNAs expression profiles in first week postpartum HM exosomes from HIV-1 infected and uninfected control mothers (n = 36). Our results indicated that HIV-1 perturbed the differential expression patterns of 19 miRNAs (13 upregulated and 6 downregulated) in HIV-1 infected women compared to healthy controls. DIANA-miR functional pathway analyses revealed that multiple biological pathways are involved including cell cycle, pathways in cancer, TGF-β signaling, FoxO signaling, fatty acid biosynthesis, p53 signaling and apoptosis. Moreover, the receiver operating characteristics (ROC) curve analyses of miR-630 and miR-378g yielded areas under the ROC curves of 0.82 (95% CI 0.67 to 0.82) and 0.83 (95% CI 0.67 to 0.83), respectively highlighting their potential to serve as biomarkers to identify HIV-1 infection in women. These data may contribute to the development of new therapeutic strategies in prevention of mother-to-child transmission (MTCT) of HIV-1.

The Role of TGF-β Signaling Regulatory MicroRNAs in the Pathogenesis of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers globally and is associated with a high mortality rate. The transforming growth factor beta (TGF-β) signaling pathway plays an important role in normal intestinal tissue function, but has also been implicated in the development of CRC. MicroRNAs (miRNAs) have also recently emerged as important regulators of cancer development and progression. They act by targeting multiple signaling pathways including the TGF-β signaling pathway. There is growing evidence demonstrating that miRNAs target various components of the TGF-β signaling pathway, including TGF-β1, TGF-β2, regulatory SMADs (SMAD1, 2, 3, 5 and 9), co-mediator SMAD4, inhibitory SMADs (SMAD6 and 7) and the TGF-β receptors, and thereby alter the proliferation and migration of CRC cells. In this review, we summarize the data concerning the interaction between TGF-β signaling pathway and miRNAs with the aim to better understanding the CRC molecular mechanisms and hence better management of this disease.

Exosome-Mediated MiR-155 Transfer Contributes to Hepatocellular Carcinoma Cell Proliferation by Targeting PTEN

BACKGROUND Most eukaryocytes release nano vesicles (30-120 nm), named exosomes, to various biological fluids such as blood, lymph, and milk. Hepatocellular carcinoma (HCC) is one of the tumors with the highest incidence rate in primary malignant carcinoma of the liver. However, the mechanism of HCC proliferation remains elusive. In this study, we aim to explore whether HCC cell-derived exosomes affect the proliferation of cancer cells. MATERIAL AND METHODS Exosomes were isolated from HCC cells by ultracentrifugation and were visualized the phenotype by transmission electron microscopy. Cell proliferation was detected by Cell Counting Kit-8 assays and EdU (5-ethynyl-2-deoxyuridine) incorporation assays. Dual-luciferase assays were performed to validate the paired correlation of miR-155 and 3'-UTR of PTEN (gene of phosphate and tension homology deleted on chromosome 10). A xenograft mice model was constructed to verify the effect of exosome-mediated miR-155 on cell proliferation in vivo. RESULTS Our finding showed that miR-155 was enriched in exosomes released from HCC cells. The exosome-containing miR-155 transferred into new HCC targeted cells and lead to the elevation of HCC cells' proliferation. Besides, the exosomal miR-155 directly bound to 3'-UTR of PTEN leading to the reduction of relevant targets in recipient liver cells. The knockdown of PTEN attenuated the proliferation of HCC cells treated with the exosomal miR-155. Moreover, nude-mouse experiment results revealed a promotional effect of the exosomal miR-155 on HCC cell-acquired xenografts. CONCLUSIONS Our study indicated that exosomal-specific miR-155 transfers to adjacent and/or more distant cells and stimulates the proliferation of HCC cells.

Epithelial-Mesenchymal Transition-Related MicroRNAs and Their Target Genes in Colorectal Cancerogenesis

MicroRNAs of the miR-200 family have been shown experimentally to regulate epithelial-mesenchymal transition (EMT). Although EMT is the postulated mechanism of development and progression of colorectal cancer (CRC), there are still limited and controversial data on expression of miR-200 family and their target genes during CRC cancerogenesis. Our study included formalin-fixed paraffin-embedded biopsy samples of 40 patients (10 adenomas and 30 cases of CRC with corresponding normal mucosa). Expression of miR-141, miR-200a/b/c and miR-429 and their target genes (CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2) was analysed using quantitative real-time PCR. Expression of E-cadherin was analysed using immunohistochemistry. All miRNAs were down-regulated and their target genes showed the opposite expression in CRC compared to adenoma. Down-regulation of the miR-200 family at the invasive front in comparison to the central part of tumour was observed as well as a correlation of expression of miR-200b, CDKN1B, ONECUT2 and ZEB2 expression to nodal metastases. Expression of the miR-200 family and SOX2 also correlated with E-cadherin staining. These results suggest that the miR-200 family and their target genes contribute to progression of adenoma to CRC, invasive properties and development of metastases. Our results strongly support the postulated hypotheses of partial EMT and intra-tumour heterogeneity during CRC cancerogenesis.

Intricate crosstalk between MYC and non-coding RNAs regulates hallmarks of cancer

Myelocytomatosis viral oncogene homolog (MYC) plays an important role in the regulation of many cellular processes, and its expression is tightly regulated at the level of transcription, translation, protein stability, and activity. Despite this tight regulation, MYC is overexpressed in many cancers and contributes to multiple hallmarks of cancer. In recent years, it has become clear that noncoding RNAs add a crucial additional layer to the regulation of MYC and its downstream effects. So far, twenty-five microRNAs and eighteen long noncoding RNAs that regulate MYC have been identified. Thirty-three miRNAs and nineteen lncRNAs are downstream effectors of MYC that contribute to the broad oncogenic role of MYC, including its effects on diverse hallmarks of cancer. In this review, we give an overview of this extensive, multilayered noncoding RNA network that exists around MYC. Current data clearly show explicit roles of crosstalk between MYC and ncRNAs to allow tumorigenesis.

Exosome-mediated miR-200b promotes colorectal cancer proliferation upon TGF-β1 exposure

Exosome are emerging mediators of intercellular communication. Cancer-secreted exosome has an effect on the exosome donor cells and support cancer growth and metastasis. Here, we examine the TGF-β1, a multifunctional cytokine involved in the regulation of cellular signaling pathways in human cancers, significantly contributes to upregulate miR-200b in exosome from colorectal cancer cell lines. The miR-200b enriched in exosome can be transferred into a new target cell to facilitating the colorectal cancer cells proliferation. Further studies showing that the exosomal miR-200b could directly target 3'-UTRs of p27 and RND3 resulted in knockdown of respective target proteins in recipient cells. Remarkably, the overexpression of p27/kip1 in HCT-116 cell, not RND3, resulted in effectively inhibited cell proliferation which induced by exosomal miR-200b. Moreover, animal experiment studies also confirmed a stimulating effect of exosomal miR-200b on colorectal cancer cell-derived xenografts. The expression p27/kip1 have decreased in tumors xenografts after injected with exosomal miR-200b. Our observations offer an evidence that whereby exosomal specific miRNA could amplify the proliferative element into the neighboring or distant cells to effective tumor growth.

Disruption of the c-Myc/miR-200b-3p/PRDX2 regulatory loop enhances tumor metastasis and chemotherapeutic resistance in colorectal cancer

BACKGROUND

Metastasis is a major threat to colorectal cancer (CRC) patients. We have reported that peroxiredoxin-2 (PRDX2) is associated with CRC invasion and metastasis. However, the mechanisms regulating PRDX2 expression remain unclear. We investigate whether microRNAs (miRNAs) regulate PRDX2 expression in CRC progression.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) was used to measure microRNA-200b-3p (miR-200b-3p) expression. Immunohistochemistry (IHC) was performed to detect c-Myc and PRDX2 protein levels in CRC tissue samples (n = 97). Western blot was used to quantify PRDX2, c-Myc, AKT2/GSK3β pathway-associated proteins and epithelial-mesenchymal transition (EMT)-related proteins in CRC cells. Luciferase reporter assays were used to analyze the interaction between miR-200b-3p and 3'untranslated region (3'UTR) of PRDX2 mRNA and AKT2 mRNA as well as c-Myc and the miR-200b-3p promoter. Chromatin immunoprecipitation (ChIP) assay was used to evaluate binding of c-Myc to the miR-200b-3p promoter. Invasive assay and metastatic model were used to assess invasive and metastatic capacities of CRC cells in vitro and in vivo. Moreover, drug-induced apoptosis was measured by flow cytometry.

RESULTS

We found that miR-200b-3p was significantly downregulated, whereas c-Myc and PRDX2 were upregulated in metastatic CRC cells and CRC tissues compared to their counterparts. An inverse correlation existed between c-Myc and miR-200b-3p, and between miR-200b-3p and PRDX2. We also found that PRDX2 was a target of miR-200b-3p. Importantly, overexpression of nontargetable PRDX2 eliminated the suppressive effects of miR-200b-3p on proliferation, invasion, EMT, chemotherapeutic resistance and metastasis of CRC cells. Moreover, c-Myc bound to the promoter of miR-200b-3p and repressed its transcription. In turn, miR-200b-3p disrupted the stability of c-Myc protein by inducing c-Myc protein threonine 58 (T58) phosphorylation and serine 62 (S62) dephosphorylation via AKT2/GSK3β pathway.

CONCLUSIONS

Our findings reveal that the c-Myc/miR-200b/PRDX2 loop regulates CRC progression and its disruption enhances tumor metastasis and chemotherapeutic resistance in CRC.

Examining plasma microRNA markers for colorectal cancer at different stages

Circulating microRNAs (miRNAs) have emerged as promising biomarkers; however, few miRNAs have been reproducible and can be used in clinical practice. In this study, we screened the levels of 754 miRNAs using TaqMan array in 50 individual plasma samples from 10 demographically matched healthy controls and 40 colorectal cancer (CRC) patients (10 each of stage I-IV) and identified 22 miRNAs associated with the presence of and stages of CRC. Then we performed the validation for 11 miRNAs in an independent cohort including 187 CRC cases and 47 healthy controls. Comprehensive analyses showed that plasma miR-96 distinguished stage I-IV CRC from healthy controls with an area under curve (AUC) of 0.740; miR-203 separated stage III-IV CRC patients from stage I-II with an AUC of 0.757; and miR-141 differentiated stage IV CRC from stage I-III patients with an AUC of 0.851. Survival analyses showed that plasma miR-96 and miR-200b were independent prognostic factors for overall survival. Thus, we propose four miRNAs (miR-96, miR-203, miR-141 and miR-200b) as clinically validated circulating biomarkers for CRC prognosis that warrant further evaluation for clinical utility.

Leuconostoc mesenteroides-derived anticancer pharmaceuticals hinder inflammation and cell survival in colon cancer cells by modulating NF-κB/AKT/PTEN/MAPK pathways

Promising results from different studies on the effect of probiotics in cancer prevention and therapy have so far been reported. However, the molecular mechanism of the interaction of probiotics with cancer cells is yet to be fully understood. In the present study, Leuconostoc mesenteroides was isolated from traditional dairy products, and its probiotic characteristics were determined. HT-29 cells were treated with conditioned-medium of designated bacteria and the cell apoptosis was studied at cellular and molecular level using DAPI staining, flow cytometry, DNA ladder assays, and real-time quantitative-PCR (q-PCR). Based on our findings, L. mesenteroides promoted apoptosis in colon cancer cell line by upregulation of MAPK1, Bax, and caspase 3, and downregulation of AKT, NF-κB, Bcl-_XL expressions and some key oncomicroRNAs such as miRNA-21 and miRNA-200b significantly (p≤0.03). The results indicated the likelihood of the examined probiotic as an alternative or complementary treatment modality in signaling-targeted cancer therapy.

Comprehensive candidate gene analysis for symptomatic or asymptomatic outcomes of Leishmania infantum infection in Brazil

Genetic risk factors contribute to asymptomatic versus symptomatic visceral leishmaniasis (VL) outcomes following infection with Leishmania infantum. We therefore carried out a family-based (n = 918 post-quality control fully genotyped and phenotyped individuals) candidate gene study for symptomatic VL or asymptomatic delayed-type hypersensitivity (DTH) skin test phenotypes in highly endemic neighborhoods of northeast Brazil. A total of 248 SNPs were genotyped in 42 genes selected as candidates on the basis of prior genetic, immunological, and transcriptional profiling studies. The most significant association with the VL phenotype was with SNP rs6785358 (P = 5.7e-04; p_corrected = 0.026) 3.8 kb upstream of TGFBR2, the gene encoding the type 2 receptor for transforming growth factor beta (TGFβ). A second inhibitory member of the TGBβ superfamily signaling pathway, SMAD7, was associated with the DTH phenotype (SNP rs7238442: P = 0.001; p_corrected = 0.051). The most significant association for the DTH phenotype was with SNP rs10800309 (P = -8.4e-06; p_corrected = 3.9e-04) situated 3.1 kb upstream of FCGR2A, the gene encoding the low-affinity IIa receptor for the Fc fragment of IgG. Overall, our results imply a role for IgG-mediated inflammation in determining DTH associated with asymptomatic infection and contribute to growing evidence that the TGFβ pathway is important in the immunopathogenesis of VL.

Rnd3 in Cancer: A Review of the Evidence for Tumor Promoter or Suppressor

Rho-GTPases are members of the Ras superfamily of small GTPases and are general modulators of important cellular processes in tumor biology such as migration and proliferation. Among these proteins, Rnd3/RhoE, an atypical Rho-GTPase devoid of GTP hydrolytic activity, has recently been studied for its putative role in tumorigenesis. Indeed, Rnd3 is implicated in processes, such as proliferation and migration, whose deregulation is linked to cancer development and metastasis. The aim of this review is to provide an overview of the data surrounding Rnd3 deregulation in cancers, its origin, and consequences. Presented here is a comprehensive account of the expression status and biological output obtained in prostate, liver, stomach, colon, lung, and brain cancers as well as in melanoma and squamous cell carcinoma. Although there appears to be no general consensus about Rnd3 expression in cancers as this protein is differently altered according to the tumor context, these alterations overwhelmingly favor a protumorigenic role. Thus, depending on the tumor type, it may behave either as a tumor suppressor or as a tumor promoter. Importantly, the deregulation of Rnd3, in most cases, is linked to patient poor outcome.

IMPLICATIONS

Rnd3 has prognostic marker potential as exemplified in lung cancers and Rnd3 or Rnd3-associated signaling pathways may represent a new putative therapeutic target. Mol Cancer Res; 14(11); 1033-44. ©2016 AACR.

miR-222 confers the resistance of breast cancer cells to Adriamycin through suppression of p27(kip1) expression

Adriamycin (Adr) is a potent chemotherapeutic agent for chemotherapy of breast cancer patients. Despite impressive initial clinical responses, some developed drug resistance to Adr-based therapy and the mechanisms underlying breast cancer cells resistance to Adr are not well known. In our previous study, in vitro, we verified that miR-222 was upregulated in Adr-resistant breast cancer cells (MCF-7/Adr) compared with the sensitive parental cells (MCF-7/S). Here, miR-222 inhibitors or mimics were transfected into MCF-7 cell lines. RT-qPCR and western blot were used to detect the expression of p27(kip1). Immunofluorescence showed that miR-222 altered the subcellular location of p27(kip1) in nucleus. MTT was employed to verify the sensitivity of breast cancer cell lines to Adr. Flow cytometry showed the apoptosis and cell cycles of the cells after adding Adr. The results showed that downregulation of miR-222 in MCF-7/Adr increased sensitivity to Adr and Adr-induced apoptosis, and arrested the cells in G1 phase, accompanied by more expressions of p27(kip1), especially in nucleus. Furthermore, overexpressed miR-222 in MCF-7/S had the inverse results. Taken together, the results found that miR-222 induced Adr-resistance at least in part via suppressing p27(kip1) expression and altering its subcellular localization, and miR-222 inhibitors could reverse Adr-resistance of breast cancer cells. These results disclosed that the future holds much promise for the targeted therapeutic in the treatment of Adr-resistant breast cancer.

MicroRNA-200b acts as a tumor suppressor in osteosarcoma via targeting ZEB1

Osteosarcoma is the most common type of cancer that develops in bone, mainly arising from the metaphysis of the long bones. MicroRNA (miR)-200b has been found to generally act as a tumor suppressor in multiple types of human cancers. However, the detailed role of miR-200b in osteosarcoma still remains to be fully understood. This study aimed to investigate the exact role of miR-200b in the progression of osteosarcoma and the underlying mechanism. Real-time reverse transcription-polymerase chain reaction data showed that miR-200b was significantly downregulated in osteosarcoma tissues compared to their matched adjacent nontumor tissues. Low miR-200b level was associated with the advanced clinical stage and positive distant metastasis. Besides, it was also downregulated in osteosarcoma cell lines (U2OS, Saos2, HOS, and MG63) compared to normal osteoblast cell line NHOst. In vitro study showed that restoration of miR-200b led to a significant decrease in proliferation, migration, and invasion of osteosarcoma cells. Moreover, ZEB1 was identified as a target gene of miR-200b, and its expression levels were negatively mediated by miR-200b in osteosarcoma cells. In addition, ZEB1 was significantly upregulated in osteosarcoma cells compared to the normal osteoblast cell line NHOst, and inhibition of ZEB1 expression also suppressed the proliferation, migration, and invasion in osteosarcoma cells. Finally, we showed that ZEB1 was frequently upregulated in osteosarcoma tissues compared to their matched adjacent normal tissues, and its expression was reversely correlated to the miR-200b levels in osteosarcoma tissues. Based on these findings, our study suggests that miR-200b inhibits the proliferation, migration, and invasion of osteosarcoma cells, probably via the inhibition of ZEB1 expression. Therefore, miR-200b/ZEB1 may become a potential target for the treatment of osteosarcoma.

RhoE is required for contact inhibition and negatively regulates tumor initiation and progression

RhoE is a small GTPase involved in the regulation of actin cytoskeleton dynamics, cell cycle and apoptosis. The role of RhoE in cancer is currently controversial, with reports of both oncogenic and tumor-suppressive functions for RhoE. Using RhoE-deficient mice, we show here that the absence of RhoE blunts contact-inhibition of growth by inhibiting p27Kip1 nuclear translocation and cooperates in oncogenic transformation of mouse primary fibroblasts. Heterozygous RhoE+/gt mice are more susceptible to chemically induced skin tumors and RhoE knock-down results in increased metastatic potential of cancer cells. These results indicate that RhoE plays a role in suppressing tumor initiation and progression.

The microRNA-200 family: small molecules with novel roles in cancer development, progression and therapy

MicroRNAs (miRNAs) are a large family of small non-coding RNAs that negatively regulate protein-coding gene expression post-transcriptionally via base pairing between the 5′ seed region of a miRNA and the 3′ untranslated region (3′UTR) of a messenger RNA (mRNA). Recent evidence has supported the critical role that miRNAs play in many diseases including cancer. The miR-200 family consisting of 5 members (miR-200a, -200b, -200c, -141, -429) is an emerging miRNA family that has been shown to play crucial roles in cancer initiation and metastasis, and potentially be important for the diagnosis and treatment of cancer. While miR-200s were found to be critically involved in the metastatic colonization to the lungs in mouse mammary xenograft tumor models, a large number of studies demonstrated their strong suppressive effects on cell transformation, cancer cell proliferation, migration, invasion, tumor growth and metastasis. This review aims to discuss research findings about the role of the miR-200 family in cancer initiation, each step of cancer metastatic cascade, cancer diagnosis and treatment. A comprehensive summary of currently validated miR-200 targets is also presented. It is concluded that miR-200 family may serve as novel targets for the therapy of multiple types of cancer.

microRNA miR-200b affects proliferation, invasiveness and stemness of endometriotic cells by targeting ZEB1, ZEB2 and KLF4

Endometriosis is characterized by growth of endometrial tissue at ectopic locations. Down-regulation of microRNA miR-200b is observed in endometriosis and malignant disease, driving tumour cells towards an invasive state by enhancing epithelial-to-mesenchymal transition (EMT). miR-200b up-regulation may inhibit EMT and invasive growth in endometriosis. To study its functional impact on the immortalized endometriotic cell line 12Z, the stromal cell line ST-T1b, and primary endometriotic stroma cells, a transient transfection approach with microRNA precursors was employed. Expression of bioinformatically predicted targets of miR-200b was analysed by qPCR. The cellular phenotype was monitored by Matrigel invasion assays, digital-holographic video microscopy and flow cytometry. qPCR revealed significant down-regulation of ZEB1 (P < 0.05) and ZEB2 (P < 0.01) and an increase in E-cadherin (P < 0.01). miR-200b overexpression decreased invasiveness (P < 0.0001) and cell motility (P < 0.05). In contrast, cell proliferation (P < 0.0001) and the stemness-associated side population phenotype (P < 0.01) were enhanced following miR-200b transfection. These properties were possibly due to up-regulation of the pluripotency-associated transcription factor KLF4 (P < 0.05) and require attention when considering therapeutic strategies. In conclusion, up-regulation of miR-200b reverts EMT, emerging as a potential therapeutic approach to inhibit endometriotic cell motility and invasiveness.

Pathophysiological Functions of Rnd3/RhoE

Rnd3, also known as RhoE, belongs to the Rnd subclass of the Rho family of small guanosine triphosphate (GTP)-binding proteins. Rnd proteins are unique due to their inability to switch from a GTP-bound to GDP-bound conformation. Even though studies of the biological function of Rnd3 are far from being concluded, information is available regarding its expression pattern, cellular localization, and its activity, which can be altered depending on the conditions. The compiled data from these studies implies that Rnd3 may not be a traditional small GTPase. The basic role of Rnd3 is to report as an endogenous antagonist of RhoA signaling-mediated actin cytoskeleton dynamics, which specifically contributes to cell migration and neuron polarity. In addition, Rnd3 also plays a critical role in arresting cell cycle distribution, inhibiting cell growth, and inducing apoptosis and differentiation. Increasing data have shown that aberrant Rnd3 expression may be the leading cause of some systemic diseases; particularly highlighted in apoptotic cardiomyopathy, developmental arrhythmogenesis and heart failure, hydrocephalus, as well as tumor metastasis and chemotherapy resistance. Therefore, a better understanding of the function of Rnd3 under different physiological and pathological conditions, through the use of suitable models, would provide a novel insight into the origin and treatment of multiple human diseases.

Shenling Baizhu San supresses colitis associated colorectal cancer through inhibition of epithelial-mesenchymal transition and myeloid-derived suppressor infiltration

Background

Shenling Baizhu San (SBS) is a well-known and classical Chinese medicine formula. It has been used for treatment of gastrointestinal disorders for about nine hundred years. Recent reports showed that it was effective in curing colitis and ameliorating the major manifestations of postoperational colorectal cancer (CRC). This study was to evaluate the effects of SBS on azoxymethane (AOM) and dextran sodium sulfate (DSS) induced colitis associated CRC (caCRC) and to analyze the underlying mechanism of SBS in preventing CRC.

Methods

The colon tissue of mice in different group was determined by immunohistochemistry and western blot. TGF-β1 in serum was measured by ELISA. Myeloid-derived suppressor cells (MDSCs) were identified by flow cytometry and immunohistochemistry.

Results

The formed neoplasms phenotypically resembled human caCRC with upregulated β-catenin, p53 and proliferating cell nuclear antigen (PCNA). SBS treatment reduced the death rate of mice and decreased the incidence and multiplicity of colonic neoplasms. SBS decreased the number of MDSCs and the level of transforming growth factor β1 (TGF-β1). SBS alleviated epithelial mesenchymal transition (EMT) through downregulating N-cadherin (N-cad), Vimentin, Fibronectin, Snail, and upregulating E-cadherin (E-cad). It reduced the activation of Wnt5a and EMT induced by TGF-β1.

Conclusions

SBS reduced the death rate through decreasing the incidence and multiplicity of colonic tumors. SBS lowered MDSCs infiltration and inhibited TGF-β1 induced EMT to exert its anti-caCRC effects.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0649-9) contains supplementary material, which is available to authorized users.

MicroRNA and diseases: therapeutic potential as new generation of drugs

MicroRNA (miRNA) is a small non-coding regulatory RNA of 21-25 nucleotides (nts) in length. miRNA works as a post-transcriptional regulator of a specific mRNA by inducing degradation or translation repression resulting in gene silencing. A large number of miRNA have been reported and many more are yet to be discovered. Aberrant expression of miRNA has been linked to numerous diseases. Attempts have been made to attenuate miRNA misregulation under pathophysiological conditions. Additionally, the potential use of miRNA in the diagnosis and treatment of diseases has been studied. Several preclinical and clinical results have been obtained, and miRNA-based therapeutics are still under investigations. In this review, the role of miRNA in a variety of pathological conditions has been summarized. Recent findings from preclinical and clinical investigations examining the role of miRNA as diagnostic markers, and their potential as drug candidates, are also highlighted. The current results summarized in this review may elucidate new dimensions of miRNA therapeutic and diagnostic techniques for biomedical academic and industry research.

microRNA‑25 promotes osteosarcoma cell proliferation by targeting the cell‑cycle inhibitor p27

An increasing body of evidence indicates that microRNAs (miRNAs), a class of small non‑coding RNAs, are often aberrantly expressed in human osteosarcoma. This study aimed to investigate the effects of miR‑25 and to identify its potential target genes in osteosarcoma (OS) cells. First, the expression of miR‑25 was detected by reverse transcription‑quantitative polymerase chain reaction (RT-qPCR), which revealed a significant upregulation of miR‑25 in osteosarcoma tissues compared to the adjacent healthy tissues. To investigate the role of miR‑25 in osteosarcoma cell proliferation, the miR‑25 precursor was next transfected into Saos‑2 and U2OS cells. Overexpression of miR‑25 promoted cell proliferation in vitro and tumor growth in a xenograft mouse model. In addition, our results revealed that the protein expression of p27, a cell‑cycle inhibitor, is negatively regulated by miR‑25. Restoring the p27 level in miR‑25‑overexpressing cells reversed the enhancing effect of miR‑25 on cell proliferation. Therefore, miR‑25 may act as an onco‑miRNA in osteosarcoma, which provides new perspectives in cancer treatment strategies based on molecular targeting.