MicroRNA-133a acts as a tumour suppressor in breast cancer through targeting LASP1

Expression Profiles and Interaction of MicroRNA and Transcripts in Response to Bovine Leukemia Virus Exposure

Bovine leukemia virus (BLV) infection in cattle is omnipresent, which causes significantly economical losses worldwide. The objective of this study was to determine microRNA (miRNA) and transcript profiles and to establish their relationship in response to exposure to the virus. Small noncoding and messenger RNA were extracted and sequenced from serum and white blood cells (WBCs) derived from seven BLV seropositive and seven seronegative cows. Transcriptomic profiles were generated by sequencing RNA libraries from WBC. Bta-miR-206 and bta-miR-133a-3p were differentially expressed in serum (P < 0.05). In WBC, bta-miR-335-3p, bta-miR-375, and bta-novel-miR76-3p were differentially expressed (P < 0.03). There were 64 differentially expressed transcripts (DETs). Gene ontology (GO) analysis of the DETs overexpressed in the seropositive group with GOs of response to stimulus and immune system process predicted that the DETs could potentially negatively regulate viral life cycle and viral entry or release from host cells. In addition, the DETs depleted in the seropositive group could play a role in the downregulation of antigen processing and presentation of endogenous peptide antigen via MHC class I. The differentially expressed miRNAs targeted 17 DETs, among which the expressions of bta-miR-133a-3p and bta-miR-335-3p were significantly negatively correlated with the expressions of ENSBTAT00000079143 and ENSBTAT00000066733, respectively. Under high prediction criteria, 90 targets of the differentially expressed miRNAs were all non-DETs. The most enriched biological process GO term of the targets was the RNA-dependent DNA biosynthetic process, which could be associated with virus replication. These results suggested that the differentially expressed miRNAs fine-tune most of the target genes in responding to BLV exposure. In addition, Bta-miR-206 interacted with BLV regulatory genes rex and tax by targeting their coding regions. A further study of the miRNAs and the genes may reveal the molecular mechanisms of BLV infection and uncover possible ways to prevent the infection.

Circular RNA circ_0006948 Promotes Esophageal Squamous Cell Carcinoma Progression by Regulating microRNA-3612/LASP1 Axis

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is the most prevalent malignancy worldwide. Circular RNAs (circRNAs) circ_0006948 is reported to be upregulated in ESCC cells.

AIMS

This study is designed to explore the role and mechanism of circ_0006948 in ESCC progression.

METHODS

Circ_0006948, linear FNDC3B, microRNA-3612 (miR-3612), and LIM and SH3 protein 1 (LASP1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, colony number, migration, invasion, and apoptosis were examined by Cell Counting Kit-8 (CCK-8), colony formation, transwell, and flow cytometry assays, severally. Glucose consumption, lactate production, and ATP level were measured by the corresponding kits. Protein levels of hexokinase 2 (HK2) and lactate dehydrogenase A (LDHA), and LASP1 were assessed by western blot assay. The cytoplasmic localization of circ_0006948 was identified by the subcellular fractionation assay. The binding relationship between miR-3612 and circ_0006948 or LASP1 was predicted by starBase or TargetScan and then verified by a dual-luciferase reporter assay. The biological role of circ_0006948 on ESCC tumor growth was examined by the xenograft tumor model in vivo.

RESULTS

Circ_0006948 and LASP1 were increased, and miR-3612 was decreased in ESCC tissues and cells. Furthermore, circ_0006948 knockdown could suppress cell viability, colony number, migration, invasion, glycolysis, and boost apoptosis in ESCC cells. Mechanically, circ_0006948 could act as a sponge of miR-3612 to regulate LASP1 expression. In addition, circ_0006948 silencing inhibited ESCC tumor growth in vivo.

CONCLUSION

Circ_0006948 boosted ESCC progression partly by regulating the miR-3612/LASP1 axis, providing an underlying therapeutic target for the ESCC treatment.

Circ_0075804 regulates the expression of LASP1 by Targeting miR-1287-5p and thus affects the biological process of retinoblastoma

BACKGROUND

Increasing evidence reveals that circular RNA (circRNA) dysregulation is involved in retinoblastoma (RB) pathogenesis. To further realize the development of RB, we investigated the role and regulatory mechanism of circ_0075804 in RB.

METHODS

Real-time quantitative PCR (RT-qPCR) and western blot were employed for expression analysis. CCK-8 assay, EdU assay, colony formation assay, flow cytometry assay and transwell assay were performed to monitor cell phenotypes. Xenograft models were established to monitor the role of circ_0075804 on tumor growth. Tumor growth was assessed by the expression of Ki67, N-cadherin, MMP2 and MMP9 via IHC assay. The predicted binding sites between miR-1287-5p and circ_0075804 or LIM and SH3 protein 1 (LASP1) were validated by dual-luciferase reporter assay.

RESULTS

Upregulation of circ_0075804 and LASP1, and downregulation of miR-1287-5p were shown in RB tissues and cells. Circ_0075804 knockdown repressed RB cell growth, invasion and survival, and hindered tumor development in vivo. MiR-1287-5p was targeted by circ_0075804, and its repression largely reversed the functional effects of circ_0075804 knockdown. LASP1 was a functional target of miR-1287-5p. The inhibition of miR-1287-5p upregulation on RB cell proliferation, survival and invasion was reversed by LASP1 overexpression. Moreover, circ_0075804 knockdown weakened LASP1 expression via increasing miR-1287-5p.

CONCLUSION

Circ_0075804 promotes LASP1 expression by targeting miR-1287-5p, thus acting as a contributor to RB carcinogenesis.Highlights:Circ_0075804 is overexpressed in RB.Circ_0075804 knockdown inhibits RB cell malignant phenotypes and tumor growth in vivo.Circ_0075804 regulates RB cell behaviors by targeting miR-1287-5p.MiR-1287-5p affects RB cell behaviors by binding to LASP1.Circ_0075804 regulates LASP1 expression via targeting miR-1287-5p.

Circ_0072088 knockdown contributes to cisplatin sensitivity and inhibits tumor progression by miR-944/LASP1 axis in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is an aggressive tumor that accounts for a high rate in cancer-related deaths. Cisplatin (CDDP) has been utilized to treat NSCLC. However, the efficacy of CDDP is usually restrained owing to the development of drug resistance. This study aims to reveal the molecular mechanism related to the resistance of NSCLC cells to CDDP.

METHODS

The expression levels of circRNA_0072088 (circ_0072088), microRNA-944 (miR-944) and LIM and SH3 protein 1 (LASP1) were detected by quantitative real-time PCR (qRT-PCR) in CDDP-resistant NSCLC tissues and cells. Protein expression was determined by Western blotting in CDDP-resistant NSCLC tissues and cells. The functional effects of circ_0072088, miR-944 and LASP1 on CDDP sensitivity and NSCLC progression were revealed by cell counting kit-8 (CCK-8), flow cytometry, cell colony formation, wound-healing and transwell invasion assays. The binding relationship between miR-944 and circ_0072088 or LASP1 was identified by a dual-luciferase reporter or RNA immunoprecipitation assay. The effects of circ_0072088 knockdown on tumor growth in vivo were analyzed by an in vivo tumor formation assay.

RESULTS

Circ_0072088 and LASP1 expression were significantly upregulated, while miR-944 expression was downregulated in CDDP-resistant NSCLC tissues and cells as compared to control groups. Circ_0072088 expression was significantly associated with tumor-node-metastasis stages and tumor size. Functionally, circ_0072088 knockdown improved CDDP sensitivity and repressed NSCLC cell malignancy, whereas miR-944 inhibitor hindered these effects. Mechanistically, circ_0072088 functioned as a sponge for miR-944 and miR-944 targeted LASP1. Circ_0072088 knockdown improved the sensitivity of tumor to CDDP in vivo.

CONCLUSION

Circ_0072088 silencing improved CDDP sensitivity and inhibited NSCLC progression by downregulating LASP1 expression through sponging miR-944. These data provided a novel insight into the study on the resistance of NSCLC to CDDP.

Glutamine-Derived Aspartate Biosynthesis in Cancer Cells: Role of Mitochondrial Transporters and New Therapeutic Perspectives

Simple Summary

In recent years, aspartate has been increasingly acknowledged as a critical player in the metabolism of cancer cells which use this metabolite for nucleotide and protein synthesis and for redox homeostasis. Most intracellular aspartate derives from the mitochondrial catabolism of glutamine. To date at least four mitochondrial transporters have been involved in this metabolic pathway. Their involvement appears to be cancer type-specific and dependent on glutamine availability. Targeting these mitochondrial transporters may represent a new attractive strategy to fight cancer. The aim of this review is to dissect the role of each of these transporters in relation to the type of cancer and the availability of nutrients in the tumoral microenvironment.

Abstract

Aspartate has a central role in cancer cell metabolism. Aspartate cytosolic availability is crucial for protein and nucleotide biosynthesis as well as for redox homeostasis. Since tumor cells display poor aspartate uptake from the external environment, most of the cellular pool of aspartate derives from mitochondrial catabolism of glutamine. At least four transporters are involved in this metabolic pathway: the glutamine (SLC1A5_var), the aspartate/glutamate (AGC), the aspartate/phosphate (uncoupling protein 2, UCP2), and the glutamate (GC) carriers, the last three belonging to the mitochondrial carrier family (MCF). The loss of one of these transporters causes a paucity of cytosolic aspartate and an arrest of cell proliferation in many different cancer types. The aim of this review is to clarify why different cancers have varying dependencies on metabolite transporters to support cytosolic glutamine-derived aspartate availability. Dissecting the precise metabolic routes that glutamine undergoes in specific tumor types is of upmost importance as it promises to unveil the best metabolic target for therapeutic intervention.

Regulatory roles of miRNAs 16, 133a, and 223 on osteoclastic bone destruction caused by breast cancer metastasis

Osteolytic bone metastasis leads to skeletal-related events, resulting in a decline in the patient activities and survival; therefore, it is important to understand the mechanism underlying bone metastasis. Recent studies have suggested that microRNAs (miRNAs or miRs) are involved in osteoclast differentiation and/or osteolytic bone metastasis; however, the roles of miRNAs have not been elucidated. In the present study, the roles of miRNAs in bone destruction caused by breast cancer metastasis were investigated in vitro and in vivo. miR-16, miR-133a and miR-223 were transfected into a human breast cancer cell line, MDA-MB-231. The expression of osteolytic factors in conditioned medium (miR-CM) collected from the culture of transfected cells was assessed. To evaluate the effects of miRNAs on osteoclast differentiation and activities, tartrate-resistant acid phosphatase (TRAP) staining and bone resorptive assays were performed in osteoclasts following miR-CM treatment. To create in vivo bone metastasis models for histological and morphometric evaluation, miRNA-transfected MDA-MB-231 cells were transplanted into the proximal tibia of nude mice. Expression of osteolytic factors, including receptor activator for nuclear factor-κB ligand (RANKL), interleukin (IL)-1β, IL-6, parathyroid hormone-related protein (PTHrP), and tumor necrosis factor (TNF), was increased in miR-16-CM, whereas it was decreased in both miR-133a-CM and miR-223-CM. TRAP staining and bone resorptive assays revealed that osteoclast function and activities were promoted by miR-16-CM treatment, whereas they were suppressed by miR-133a-CM and miR-223-CM. Consistent with in vitro findings, in vivo experiments revealed that the overexpression of miR-16 increased osteoclast activities and bone destruction in MDA-MB-231 cells, whereas the opposite results were observed in both miR-133a- and miR-223-transfected MDA-MB-231 cells. Our results indicated that miR-16 promoted osteoclast activities and bone destruction caused by breast cancer metastasis in the bone microenvironment, whereas miR-133a and miR-223 suppressed them. These miRNAs could be potential biomarkers and therapeutic targets for breast cancer bone metastasis.

Downregulation of MIAT reduces the proliferation and migratory and invasive abilities of retinoblastoma cells by sponging miR-665 and regulating LASP1

Long non-coding RNAs (lncRNAs) can function as onco-lncRNAs in several types of human cancer, including retinoblastoma (Rb). The present study investigated the potential role and regulatory mechanism of the lncRNA myocardial infarction-associated transcript (MIAT) in Rb. To do so, the expression levels of MIAT, microRNA (miR)-665, and LIM and SH3 protein 1 (LASP1) in Rb tissues from patients or Rb cells were analysed using reverse transcription quantitative PCR. The interactions between miR-665 and MIAT/LASP1 were confirmed by the dual-luciferase reporter assay. MTT, Transwell (to assess migration and invasion) and western blotting assays were used to explore the functions of the MIAT/miR-665/LASP1 axis on Rb progression in vitro. The results of the present study indicated that MIAT targeted miR-665. In Rb tissues and cell lines, high expression of MIAT was observed, whereas miR-665 was downregulated in Rb tissues. Furthermore, the proliferation and migratory and invasive abilities of Rb Y79 and HXO-RB44 cells were decreased following MIAT downregulation or miR-665 overexpression. In addition, LASP1 was identified as a target gene of miR-665. Both the decreased expression of miR-665 and the elevated expression of LASP1 reversed the suppressive effects of MIAT knockdown on the proliferation and migratory and invasive abilities of Y79 cells. Furthermore, MIAT silencing attenuated the development of Rb by regulating the miR-665/LASP1 axis. Taken together, these findings suggested that MIAT may be considered as a possible therapeutic target for Rb.

The miR-133a, TPM4 and TAp63γ Role in Myocyte Differentiation Microfilament Remodelling and Colon Cancer Progression

MicroRNAs (miRNAs) play an essential role in the regulation of a number of physiological functions. miR-133a and other muscular miRs (myomiRs) play a key role in muscle cell growth and in some type of cancers. Here, we show that miR133a is upregulated in individuals that undertake physical exercise. We used a skeletal muscle differentiation model to dissect miR-133a's role and to identify new targets, identifying Tropomyosin-4 (TPM4). This protein is expressed during muscle differentiation, but importantly it is an essential component of microfilament cytoskeleton and stress fibres formation. The microfilament scaffold remodelling is an essential step in cell transformation and tumour progression. Using the muscle system, we obtained valuable information about the microfilament proteins, and the knowledge on these molecular players can be transferred to the cytoskeleton rearrangement observed in cancer cells. Further investigations showed a role of TPM4 in cancer physiology, specifically, we found that miR-133a downregulation leads to TPM4 upregulation in colon carcinoma (CRC), and this correlates with a lower patient survival. At molecular level, we demonstrated in myocyte differentiation that TPM4 is positively regulated by the TA isoform of the p63 transcription factor. In muscles, miR-133a generates a myogenic stimulus, reducing the differentiation by downregulating TPM4. In this system, miR-133a counteracts the differentiative TAp63 activity. Interestingly, in CRC cell lines and in patient biopsies, miR-133a is able to regulate TPM4 activity, while TAp63 is not active. The downregulation of the miR leads to TPM4 overexpression, this modifies the architecture of the cell cytoskeleton contributing to increase the invasiveness of the tumour and associating with a poor prognosis. These results add data to the interesting question about the link between physical activity, muscle physiology and protection against colorectal cancer. The two phenomena have in common the cytoskeleton remodelling, due to the TPM4 activity, that is involved in stress fibres formation.

Long non‑coding RNA H19 regulates LASP1 expression in osteosarcoma by competitively binding to miR‑29a‑3p

A prevalent type of bone tumor, osteosarcoma (OS) is prone to pulmonary metastasis, which results in a high relapse risk and poor prognosis for patients. The progression of OS is significantly associated with the expression of long non‑coding (lnc)RNA H19. To the best of our knowledge, however, the exact molecular mechanism of this lncRNA has not been fully investigated. The present study verified the effect of H19 on the proliferation and invasion of osteosarcoma cells via in vivo and in vitro experiments, including Cell Counting Kit‑8, western blot, reverse transcription‑quantitative PCR, wound healing and Transwell assays. H19 was found to be overexpressed in OS compared with corresponding normal adjacent tissue. In addition, H19 served as a competing endogenous ncRNA targeting microRNA‑29a‑3p and activating LIM and SH3 domain protein 1 and modulating the OS cell phenotype. The results of the present study may improve understanding of OS pathogenesis.

microRNA-133a exerts tumor suppressive role in oral squamous cell carcinoma through the Notch signaling pathway via downregulation of CTBP2

microRNAs (miRNAs) have been revealed to participate in some oral cancers and are proved to be effective. In the present study, we tried to explore the biological function of miR-133a in oral squamous cell carcinoma (OSCC) cells. The relationship that C-terminal-binding proteins 2 (CTBP2) was the putative target gene of miR-133a revealed from bioinformatics analysis was further was further validated by dual-luciferase reporter gene assay. In total, 40 patients with OSCC were enrolled for characterization of miR-133a, CTBP2, and Notch signaling pathway-related gene expression in clinical OSCC tissues. Low expression of miR-133a and high expression of CTBP2, Hes1, Notch-1, and Notch-3 were determined in OSCC tissues. OSCC cell lines were transfected with miR-133a inhibitor, miR-133a mimic, or shRNA targeting CTBP2, in response to which cell proliferation, migration, invasion, cell cycle, and apoptosis were evaluated. Transfection of miR-133a mimic induced apoptosis and inhibited OSCC cell proliferation, migration, and invasion and this was demonstrated to be attributable to decreased CTBP2 expression and suppression of the Notch signaling pathway. Taken together, we concluded that miR-133a acted as a tumor suppressor in OSCC through inhibition of the Notch signaling pathway via binding to CTBP2.

Emerging roles of MiR-133a in human cancers

MicroRNAs (miRNAs) can post-transcriptionally regulate the expression of cancer-relevant genes via binding to the 3'-untranslated region (3'-UTR) of the target mRNAs. MiR-133a, as a miRNA, participate in tumorigenesis, progression, autophagy and drug-resistance in various malignancies. Based on the recent insights, we discuss the functions of miR-133a in physiological and pathological processes and its potential effects on cancer diagnosis, prognosis and therapy.

GPER1 and microRNA: Two Players in Breast Cancer Progression

Breast cancer is the main cause of morbidity and mortality in women worldwide. However, the molecular pathogenesis of breast cancer remains poorly defined due to its heterogeneity. Several studies have reported that G Protein-Coupled Estrogen Receptor 1 (GPER1) plays a crucial role in breast cancer progression, by binding to estrogens or synthetic agonists, like G-1, thus modulating genes involved in diverse biological events, such as cell proliferation, migration, apoptosis, and metastasis. In addition, it has been established that the dysregulation of short sequences of non-coding RNA, named microRNAs (miRNAs), is involved in various pathophysiological conditions, including breast cancer. Recent evidence has indicated that estrogens may regulate miRNA expression and therefore modulate the levels of their target genes, not only through the classical estrogen receptors (ERs), but also activating GPER1 signalling, hence suggesting an alternative molecular pathway involved in breast tumor progression. Here, the current knowledge about GPER1 and miRNA action in breast cancer is recapitulated, reporting recent evidence on the liaison of these two players in triggering breast tumorogenic effects. Elucidating the role of GPER1 and miRNAs in breast cancer might provide new tools for innovative approaches in anti-cancer therapy.

LASP1 induces colorectal cancer proliferation and invasiveness through Hippo signaling and Nanog mediated EMT

The role of LIM and SH3 protein 1 (LASP1) in colorectal cancer (CRC) has been described in multiple studies, however, the underlying molecular mechanisms remained inclusive. In the present study, we performed immunohistochemistry (IHC) staining for LASP1 and found that LASP1 expression was higher in CRC tissue of advanced stage. Over-expressed (OE) LASP1 promoted proliferation, tumorigenesis and migration of CRC cell lines SW480 and SW620. Using the TCGA database, we identified Yes-associated protein (YAP1) was positively correlated with LASP1 expression in CRC patients. Introducing a novel YAP1 inhibitor CA3, we found that CA3 treatment inhibited LAPS1 OE SW480 and SW620 cells proliferation, colony number formation, invasion and migration. Further mechanistic experiments showed that Nanog, a stem cell marker, was up-regulated in LASP1 OE cells but suppressed by CA3 treatment. Chromatin immunoprecipitation (CHIP) and luciferase reporter assay revealed that YAP1 can directly target the promoter region of Nanog and enhance its activity. LASP1 accelerated CRC migration through targeting YAP1-mediated vimentin and E-cadherin expression. Finally, by developing murine CRC model, we found the primary tumor size was almost abolished and the survival rate was greatly improved by chemotherapy and CA3 combined treatment compared with negative control or chemotherapy treated alone. Collectively, our findings demonstrated that LASP1 could induce CRC tumor cells proliferation and migration through activating hippo signaling pathway component YAP1 and further enhancing Nanog expression.

Transcription factor AP-4 (TFAP4)-upstream ORF coding 66 aa inhibits the malignant behaviors of glioma cells by suppressing the TFAP4/long noncoding RNA 00520/microRNA-520f-3p feedback loop

Upstream ORF (uORF) is a translational initiation element located in the 5′UTR of eukaryotic mRNAs. Studies have found that uORFs play an important regulatory role in many diseases. Based on The Cancer Genome Atlas database, the results of our experiments and previous research evidence, we investigated transcription factor AP‐4 (TFAP4) and its uORF, LIM and SH3 protein 1 (LASP1), long noncoding RNA 00520 (LINC00520), and microRNA (miR)‐520f‐3p as candidates involved in glioma malignancy, which is a poorly understood process. Both TFAP4‐66aa‐uORF and miR‐520f‐3p were downregulated, and TFAP4, LASP1, and LINC00520 were highly expressed in glioma tissues and cells. TFAP4‐66aa‐uORF or miR‐520f‐3p overexpression or TFAP4, LASP1, or LINC00520 knockdown inhibited glioma cell proliferation, migration, and invasion, but promoted apoptosis. TFAP4‐66aa‐uORF inhibited the translation of TFAP4 by binding to the TFAP4 mRNA. MicroRNA‐520f‐3p inhibited TFAP4 expression by binding to its 3′UTR. However, LINC00520 could promote the expression of TFAP4 by competitively binding to miR‐520f‐3p. In addition, TFAP4 transcriptionally activated LASP1 and LINC00520 expression by binding to their promoter regions, forming a positive feedback loop of TFAP4/LINC00520/miR‐520f‐3p. Our findings together indicated that TFAP4‐66aa‐uORF inhibited the TFAP4/LINC00520/miR‐520f‐3p feedback loop by directly inhibiting TFAP4 expression, subsequently leading to inhibition of glioma malignancy. This provides a basis for developing new therapeutic approaches for glioma treatment.

Aberrant expression of a five-microRNA signature in breast carcinoma as a promising biomarker for diagnosis

BACKGROUND

Breast cancer (BC) is the most common malignancy among females with dismal quality of life in patients. It has been proven that epigenetic factors, especially microRNAs, are involved in breast carcinogenesis and progression. This study aimed to assess the expression and clinical performances of a five-microRNA signature (miR-127-3p, miR-133a-3p, miR-155-5p, miR-199b-5p, and miR-342-5p) in breast cancer and adjacent normal tissues to identify a potential biomarker for BC and investigate the relationship between their expression and clinicopathological features of BC patients as well.

METHODS

In this case-control investigation, we recruited 50 pairs of tumor and matched non-tumor surgical specimens from patients diagnosed with BC. Expression levels of miR-127-3p, miR-133a-3p, miR-155-5p, miR-199b-5p, and miR-342-5p were measured in BC and adjacent normal tissues by RT-qPCR.

RESULTS

We found that miR-127-3p, miR-133a-3p, miR-199b-5p, and miR-342-5p were significantly down-regulated, while miR-155-5p was significantly up-regulated in BC tumor tissues compared with the corresponding adjacent normal tissues. The decreased expression of miR-127-3p, miR-133a-3p, miR-342-5p, and up-regulation of miR-155-5p showed a significant correlation with disease stage. We also found a significant down-regulation of miR-127-3p, miR-199b-5p, and miR-342-5p compared in HER-2-negative patients. Our results indicated that miR-155-5p had a higher expression level in HER-2-positive patients. Receiver operating characteristic (ROC) curve analysis demonstrated that all these five microRNAs can serve as potential biomarkers to distinguish between tumor and non-tumor breast tissue samples.

CONCLUSIONS

The present findings suggested that dysregulation of this five-miRNA signature might be considered as a promising and functional biomarker for BC diagnosis.

miR-133a-3p promotes apoptosis and induces cell cycle arrest by targeting CREB1 in retinoblastoma

INTRODUCTION

Retinoblastoma (RB) is a malignant tumor that is derived from photoreceptors. It is common in children under 3 years old with a family genetic predisposition. MicroRNA-133a-3p (miR-133a-3p) is one of the tumor-related miRNAs that interprets a critical function in the genesis and development of various tumors. This study investigated the effects and underlying mechanisms of miR-133a-3p in RB.

MATERIAL AND METHODS

Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was used to assess the miR-133a-3p expression in RB tissues and a cell model. MTT assay, western blot, flow cytometry and luciferase reporter assay were performed to evaluate the effect of miR-133a-3p on cell viability, apoptosis and the cell cycle. An RB xenograft model was established to assess the in vivo influence of miR-133a-3p on RB growth.

RESULTS

MiR-133a-3p level was reduced in RB tissues and the cell model (p < 0.01 or p < 0.001). Addition of miR-133a-3p reduced cell viability, and increased apoptosis and cell cycle arrest (p < 0.001). Additionally, CREB1 was identified to be the target of miR-133a-3p in RB cell lines (p < 0.001). Cell viability reduction, apoptosis and cell cycle arrest increases mediated by miR-133a-3p were attenuated by CREB1 overexpression (p < 0.001). MiR-133a-3p inhibited tumor growth of RB in vivo (p < 0.001).

CONCLUSIONS

Our results reveal that miR-133a-3p exhibits anti-cancer effects by targeting CREB1 in RB. This study provides a new direction for effective targeted treatment of this disease.

MicroRNA-133a inhibits the proliferation of non-small cell lung cancer by targeting YES1

Previous studies have reported that microRNA-133a (miR-133a) is involved in the pathogenesis of human cancers. This study investigated the effect of miR-133a on cell proliferation in non-small cell lung cancer (NSCLC). The expression of miR-133a and YES proto-oncogene 1 (YES1) was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay. The CCK-8 assay was used to measure cell proliferation. The relationship between miR-133a and YES1 was confirmed by dual luciferase assay. Downregulation of miR-133a was identified in NSCLC and correlated with poor prognosis in NSCLC patients. Moreover, the overexpression of miR-133a inhibited proliferation of NSCLC cells. YES1 was also confirmed as a direct target of miR-133a. Downregulation of YES1 was found to inhibit cell proliferation in NSCLC. By contrast, the upregulation of YES1 abolished the inhibitory effect of miR-133a on cell proliferation in NSCLC. miR-133a inhibited cell proliferation in NSCLC by targeting YES1, indicating that miR-133a can be used as an indicator of prognosis in NSCLC patients.

Methylation-mediated silencing of miR-133a-3p promotes breast cancer cell migration and stemness via miR-133a-3p/MAML1/DNMT3A positive feedback loop

Background

miR-133a-3p has been recently discovered to be down-regulated in various human malignancies, including breast cancer, and reduced miR-133a-3p levels have been significantly associated with breast cancer cell growth and invasion. However, the regulatory mechanisms leading to abnormal expression of miR-133a-3p in breast cancer remain obscure.

Methods

qRT-PCR was applied to detect the expression of miR-133a-3p in breast cancer tissues and cell lines. Bisulfite sequencing was used to detect the degree of methylation of the miR-133a-3p promoter. The effects of miR-133a-3p on breast cancer in vitro were examined by cell proliferation assay, transwell assay, flow cytometry, and western blotting. Bioinformatic analysis, dual-luciferase assay and RIP assay were employed to identify the interaction between miR-133a-3p and MAML1. A xenograft model was used to show the metastasis of breast cancer cells.

Results

We confirmed that miR-133a-3p was silenced by DNA hypermethylation in breast cancer cell lines and tissues, which predicted poor prognosis in breast cancer patients, and reducing miR-133a-3p expression led to a significant increase in the migration, invasion, proliferation, and stemness of breast cancer cells in vitro. Mastermind-like transcriptional coactivator 1 (MAML1) was confirmed to be a target of miR-133a-3p involved in regulating breast cancer metastasis both in vitro and in vivo. Moreover, a series of investigations indicated that MAML1 initiated a positive feedback loop, which could up-regulate DNA methyltransferase 3A (DNMT3A) to promote hypermethylation of the miR-133a-3p promoter.

Conclusion

Taken together, our findings revealed a novel miR-133a-3p/MAML1/DNMT3A positive feedback loop in breast cancer cells, which may become a potential therapeutic target for breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1400-z) contains supplementary material, which is available to authorized users.

The Regulatory Role of MicroRNAs in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules which function as critical post-transcriptional gene regulators of various biological functions. Generally, miRNAs negatively regulate gene expression by binding to their selective messenger RNAs (mRNAs), thereby leading to either mRNA degradation or translational repression, depending on the degree of complementarity with target mRNA sequences. Aberrant expression of these miRNAs has been linked etiologically with various human diseases including breast cancer. Different cellular pathways of breast cancer development such as cell proliferation, apoptotic response, metastasis, cancer recurrence and chemoresistance are regulated by either the oncogenic miRNA (oncomiR) or tumor suppressor miRNA (tsmiR). In this review, we highlight the current state of research into miRNA involved in breast cancer, with particular attention to articles published between the years 2000 to 2019, using detailed searches of the databases PubMed, Google Scholar, and Scopus. The post-transcriptional gene regulatory roles of various dysregulated miRNAs in breast cancer and their potential as therapeutic targets are also discussed.

A rectified factor network based biclustering method for detecting cancer-related coding genes and miRNAs, and their interactions

Detecting cancer-related genes and their interactions is a crucial task in cancer research. For this purpose, we proposed an efficient method, to detect coding genes, microRNAs (miRNAs), and their interactions related to a particular cancer or a cancer subtype using their expression data from the same set of samples. Firstly, biclusters specific to a particular type of cancer are detected based on rectified factor networks and ranked according to their associations with general cancers. Secondly, coding genes and miRNAs in each bicluster are prioritized by considering their differential expression and differential correlation values, protein-protein interaction data, and potential cancer markers. Finally, a rank fusion process is used to obtain the final comprehensive rank by combining multiple ranking results. We applied our proposed method on breast cancer datasets. Results show that our method outperforms other methods in detecting breast cancer-related coding genes and miRNAs. Furthermore, our method is very efficient in computing time, which can handle tens of thousands genes/miRNAs and hundreds of patients in hours on a desktop. This work may aid researchers in studying the genetic architecture of complex diseases, and improving the accuracy of diagnosis.

SNV discovery and functional candidate gene identification for milk composition based on whole genome resequencing of Holstein bulls with extremely high and low breeding values

We have sequenced the whole genomes of eight proven Holstein bulls from the four half-sib or full-sib families with extremely high and low estimated breeding values (EBV) for milk protein percentage (PP) and fat percentage (FP) using Illumina re-sequencing technology. Consequently, 2.3 billion raw reads were obtained with an average effective depth of 8.1×. After single nucleotide variant (SNV) calling, total 10,961,243 SNVs were identified, and 57,451 of them showed opposite fixed sites between the bulls with high and low EBVs within each family (called as common differential SNVs). Next, we annotated the common differential SNVs based on the bovine reference genome, and observed that 45,188 SNVs (78.70%) were located in the intergenic region of genes and merely 11,871 SNVs (20.67%) located within the protein-coding genes. Of them, 13,099 common differential SNVs that were within or close to protein-coding genes with less than 5 kb were chosen for identification of candidate genes for milk compositions in dairy cattle. By integrated analysis of the 2,657 genes with the GO terms and pathways related to protein and fat metabolism, and the known quantitative trait loci (QTLs) for milk protein and fat traits, we identified 17 promising candidate genes: ALG14, ATP2C1, PLD1, C3H1orf85, SNX7, MTHFD2L, CDKN2D, COL5A3, FDX1L, PIN1, FIG4, EXOC7, LASP1, PGS1, SAO, GPLD1 and MGEA5. Our findings provided an important foundation for further study and a prompt for molecular breeding of dairy cattle.

Curcumin up-regulates miR-133a expression to inhibit hepatocellular carcinoma cell migration and invasion

BACKGROUND

Curcumin has a good inhibitory effect on the occurr-ence and development of many kinds of tumors, including hepatocellular carcinoma, but its anti-hepatocellular carcinoma mechanism is not completely clear. Some studies have found that curcumin can inhibit the proliferation and metastasis of gastric cancer cells by regulating the expression of miR-133a. The low expression of miR-133a in hepatocellular carcinoma has been confirmed by data, but whether curcumin regulated expression of miR-133a plays an anti-hepatocellular carcinoma role is not clear.

AIM

To investigate the effect of curcumin on the migration and invasion of hepatocellular carcinoma cells and explore the underlying mechanism by detecting the expression of miR-133a.

METHODS

After treatment of liver cancer SMMC-7721 cells with curcumin (0, 10, and 20 μmol/L) for 48 h, cell viability was detected by MTT assay, cell migration and invasion were measured by transwell assay, and the expression of miR-133a in the cells was detected by RT-PCR. The expression of miR-133a in normal liver LO2 cells and hepatocellular carcinoma SMMC-7721 cells was detected by RT-PCR. After transfection with miR-133a analogue to SMMC-7721 cells, the effect of miR-133a on migration and invasion of cells before and after curcumin treatment was detected by transwell assay.

RESULTS

Curcumin effectively inhibited SMMC-7721 cell viability (10 μmol/L curcumin: 0.71 + 0.07 vs 1.02 + 0.09; 20 μmol/L: 0.45 + 0.05 vs 1.02 + 0.09), migration (52.32 ± 5.48 vs 121.43 ± 12.35), and invasion (46.33 ± 5.38 vs 109.25 ± 10.75) and increased miR-133a expression (10 μmol/L curcumin: 1.62 ± 0.11 vs 1.00 ± 0.09; 20 μmol/L: 2.96 ± 0.25 vs 1.00 ± 0.09). Compared with LO2 cells, the expression level of miR-133a (0.32 ± 0.03 vs 1.03 ± 0.08) in SMCC-7721 cells was decreased obviously. After increasing the expression of miR-133a, the migration (32.84 ± 3.95 vs 96.35 ± 9.08) and invasion (42.75 ± 5.06 vs 119.32 ± 11.71) of SMCC-7721 cells were significantly decreased, and the inhibitory effect of curcumin on migration (29.6 ± 3.32 vs 134.62 ± 13.41) and invasion (31.86 ± 4.05 vs 129.73 ± 12.74) of SMCC-7721 cells was enhanced.

CONCLUSION

Curcumin can inhibit the migration and invasion of hepatoma cells by up-regulating the expression of miR-133a.

MicroRNAs contribute to ATP-binding cassette transporter- and autophagy-mediated chemoresistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has an elevated mortality rate, largely because of high recurrence and metastasis. Additionally, the main obstacle during treatment of HCC is that patients usually develop resistance to chemotherapy. Cancer drug resistance involves many different mechanisms, including alterations in drug metabolism and processing, impairment of the apoptotic machine, activation of cell survival signaling, decreased drug sensitivity and autophagy, among others. Nowadays, miRNAs are emerging as master regulators of normal physiology- and tumor-related gene expression. In HCC, aberrant expression of many miRNAs leads to chemoresistance. Herein, we particularly analyzed miRNA impact on HCC resistance to drug therapy. Certain miRNAs target ABC (ATP-binding cassette) transporter genes. As most of these miRNAs are downregulated in HCC, transporter levels increase and intracellular drug accumulation decrease, turning cells less sensitive to death. Others miRNAs target autophagy-related gene expression, inhibiting autophagy and acting as tumor suppressors. Nevertheless, due to its downregulation in HCC, these miRNAs do not inhibit autophagy or tumor growth and, resistance is favored. Concluding, modulation of ABC transporter and/or autophagy-related gene expression or function by miRNAs could be determinant for HCC cell survival under chemotherapeutic drug treatment. Undoubtedly, more insights on the biological processes, signaling pathways and/or molecular mechanisms regulated by miRNAs are needed. Anyway, miRNA-based therapy together with conventional chemotherapeutic drugs has a great future in cancer therapy.

miR-143 inhibits migration and invasion through regulating LASP1 in human esophageal cancer

BACKGROUND

Esophageal cancer (EC) is one of the common cancers in China with high incidence and poor prognosis. Increasing evidence has emphasized the important roles of differentially expressed miRNAs in esophageal squamous cell carcinoma (ESCC) progression. Previous studies indicated that miR-143-3p and LASP1 influence cell growth in ESCC and other cancer types. However, the function and molecular mechanism of action of miR-143 and LASP1 in ESCC have not been fully explored.

METHODS

miR-143 and LASP1 expression were detected by quantitative real-time PCR. The protein level of LASP1 was measured by western blot. Cell proliferation was evaluated by MTT assay. Cell migration and invasion capacity was measured by transwell assay. Targeting of LASP1 mRNA by miR-143 was verified by luciferase reporter assay. Overall survival of ESCC patients with different miR-143 expression level was evaluated by Kaplan-Meier survival analysis.

RESULTS

miR-143 expression was down-regulated, while LASP1 expression was up-regulated in ESCC tissues and cells compared to non-malignant counterparts. LASP1 mRNA was identified as a target of miR-143. Low miR-143 expression or high LASP1 expression significantly associated with ESCC patients' decreased survival. miR-143 mimic transfection inhibited ESCC cell proliferation, migration and invasion in vitro, which was impaired by LASP1 overexpression.

CONCLUSION

miR-143 suppressed cell proliferation, migration, and invasion by down-regulating LASP1.

Expression signatures and roles of microRNAs in inflammatory breast cancer

Inflammatory breast cancer (IBC) is an infrequent but aggressive manifestation of breast cancer, which accounts for 2-4% of all breast cancer cases but responsible for 7-10% of breast cancer-related deaths, and with a 20-30% 10-year overall survival compared with 80% for patients with non-IBC with an unordinary phenotype, whose molecular mechanisms are still largely unknown to date. Discovering and identifying novel bio-markers responsible for diagnosis and therapeutic targets is a pressing need. MicroRNAs are a class of small non-coding RNAs that are capable to post-transcriptionally regulate gene expression of genes by targeting mRNAs, exerting vital and tremendous affects in numerous malignancy-related biological processes, including cell apoptosis, metabolism, proliferation and differentiation. In this study, we review present and high-quality evidences regarding the potential applications of inflammatory breast cancer associated microRNAs for diagnosis and prognosis of this lethal disease.

Puerarin promotes DUSP1 expression by regulating miR‑133a‑3p in breast cancer

Previous studies demonstrated that puerarin represents a potential therapeutic drug for breast cancer treatment, due to its ability to inhibit the migration of MCF-7 and MDA-MB-231 cell lines. In order to investigate the mechanism of puerarin in breast cancer cells, the aim of the present study was to examine whether puerarin regulated the dual specificity phosphatase 1 (DUSP1) expression level by promoting the microRNA-133a-3p (miR-133a-3p) expression level in breast cancer. Cell viability and apoptosis were assessed in HCC38 cells by Cell Counting Kit-8 assays and a flow cytometry assay, respectively. In total, four treatment groups were considered: Puerarin treatment, miR-133a-3p mimics transfection, puerarin + miR-133a-3p mimics and negative control. miR-133a-3p expression and DUSP1 mRNA expression levels were analyzed by reverse transcription-quantitative polymerase chain reaction, and western blotting was used to detect the protein expression level. Furthermore, a luciferase reporter gene assay was used to test whether DUSP1 mRNA was a direct target of miR-133a-3p. The present results suggested that treatment with puerarin or miR-133a-3p mimics transfection affected the miR-133a-3p expression level and the activity of the DUSP1/p38 pathway, leading to inhibition of HCC38 cell viability and an increase in apoptosis. miR-133a-3p overexpression enhanced the drug action of peurarin. In conclusion, puerarin may increase DUSP1 expression by promoting the miR-133a-3p expression level in HCC38 breast cancer cells. Therefore, miR-133a-3p may represent a novel molecular marker for diagnosis and treatment of breast cancer, and puerarin may represent a promising clinical drug for treatment of patients with breast cancer.

New Frontiers for the Cytoskeletal Protein LASP1

In the recent two decades, LIM and SH3 protein 1 (LASP1) has been developed from a simple actin-binding structural protein to a tumor biomarker and subsequently to a complex, nuclear transcriptional regulator. Starting with a brief historical perspective, this review will mainly compare and contrast LASP1 and LASP2 from the angle of the newest data and importantly, examine their role in transcriptional regulation. We will summarize the current knowledge through pictorial models and tables including the roles of different microRNAs in the differential regulation of LASP1 levels and patient outcome rather than specify in detail all tumor entities. Finally, the novel functional roles of LASP1 in secretion of vesicles, expression of matrix metalloproteinases and transcriptional regulation as well as the activation of survival and proliferation pathways in different cancer types are described.

Aloperine inhibits proliferation, migration and invasion and induces apoptosis by blocking the Ras signaling pathway in human breast cancer cells

Aloperine (Alo), as a quinolizidine alkaloid extracted from S. alopecuroide, has the positive activities of anti-inflammatory, anti-allergenic, antitumor and anti-viral. However, the role and mechanism of Alo in breast cancer have not been studied yet. In the present study, Alo markedly inhibited the proliferation and suppressed the colony formation ability of the breast cancer cell lines MCF-7 and MDA-MB-231 in a dose-dependent manner by Cell Counting kit-8 and colony formation assays, respectively. In addition, the results of confocal microscopy analysis and flow cytometry detection revealed that Alo induced the apoptosis of MCF-7 and MDA-MB-231 cells, and western blotting indicated that Alo upregulated the protein levels of Bax, caspase-3 and caspase-9, and downregulated the expression of Bcl-2. Furthermore, the results of wound healing, Transwell migration and invasion assays demonstrated that Alo inhibited the migration and invasion of MCF-7 and MDA-MB-231 cells, and reduced the protein levels of matrix metalloproteinase (MMP)-2 and MMP-9. Alo also downregulated the protein expressions of Ras, phosphorylated (p)-Raf proto-oncogene, serine/threonine kinase 1 and p-extracellular signal-regulated kinase 1/2. Furthermore, ISIS 2503, a Ras inhibitor, inhibited colony formation, induced apoptosis, and suppressed the migration and invasion of MCF-7 and MDA-MB-231 cells. These effects were more marked in the presence of ISIS 2503 and Alo, when compared with those of either agent alone. In conclusion, the present study reported a novel use of Alo in inhibiting the proliferation, migration and invasion, and inducing the apoptosis of human breast cancer cells by blocking the Ras signaling pathway.