Luciferase Reporter Vector Research Articles

Crosstalk between TGFβ and Wnt signaling pathways in the human trabecular meshwork

Primary Open Angle Glaucoma (POAG) is an irreversible, vision-threatening disease that affects millions worldwide. The principal risk factor of POAG is increased intraocular pressure (IOP) due to pathological changes in the trabecular meshwork (TM). The TGFβ signaling pathway activator TGFβ2 and the Wnt signaling pathway inhibitor secreted frizzled-related protein 1 (sFRP1) are elevated in the POAG TM. In this study, we determined whether there is a crosstalk between the TGFβ/Smad pathway and the canonical Wnt pathway using luciferase reporter assays. Lentiviral luciferase reporter vectors for studying the TGFβ/Smad pathway or the canonical Wnt pathway were transduced into primary human non-glaucomatous TM (NTM) cells. Cells were treated with or without a combination of 5 μg/ml TGFβ2 and/or 100 ng/ml Wnt3a recombinant proteins, and luciferase levels were measured using a plate reader. We found that TGFβ2 inhibited Wnt3a-induced canonical Wnt pathway activation, while Wnt3a inhibited TGFβ2-induced TGFβ/Smad pathway activation (n = 6, p < 0.05) in 3 NTM cell strains. We also found that knocking down of Smad4 or β-catenin using siRNA in HTM5 cells transfected with similar luciferase reporter plasmids abolished the inhibitory effect of TGFβ2 and/or Wnt3a on the other pathway (n = 6). Our results suggest the existence of a cross-inhibition between the TGFβ/Smad and canonical Wnt pathways in the TM, and this cross-inhibition may be mediated by Smad4 and β-catenin.

NF-κB/Rel, not STAT5, regulates nitric oxide synthase transcription in Apostichopus japonicus

Nitric oxide (NO) is an important signaling molecular in the immune system of all vertebrates and invertebrates for pathologic and physiologic process, and it is largely produced by inducible nitric oxide synthase (iNOS). To uncover key mechanisms regulating NOS expression in sea cucumber Apostichopus japonicus, we amplified a fragment of the NOS promoter by genome walking approach and characterized putative transcription factor binding motifs using luciferase assay. Transient transfection of EPC cells using 5′-deletion constructs linked to luciferase reporter revealed that the region −614/+39 contributed importantly to expression of the AjNOS gene, and the −614 bp of the 5′-flanking region of the AjNOS gene responded well to LPS. Analysis of the functional promoter region revealed the presence of two potential NF-κB (−375 bp to −366 bp, −76 bp to −67 bp) and three STAT binding sites (−284 bp to −276 bp, −95 bp to 87 bp, −81 bp to −73 bp). When luciferase reporter vector and expression vector co-transfected revealed that NF-κB/Rel, but not STAT5, activate the AjNOS promoter fragment. Furthermore, two truncated reporter vectors co-transfected with vector expressing NF-κB/Rel revealed that the first NF-κB binding site (−375 bp to −366 bp) was essential for the ability of this promoter to induce AjNOS transcription. In addition, blocking the AjRel by SN50 (NF-κB inhibitory peptide) depressed the AjNOS expression and NO production both in vivo and in vitro, respectively, revealing that AjRel might directly modulate AjNOS. All our findings confirmed that NF-κB dependent mechanisms regulating expression of AjNOS and suggested a means of linking NO production to the immune response.

MicroRNA-200b inhibits epithelial-mesenchymal transition and migration of cervical cancer cells by directly targeting RhoE.

Previous studies have identified microRNA-200b (miR-200b) as a powerful regulator of epithelial-mesenchymal transition (EMT) via the control of gene expression. EMT is a critical event that is associated with the initiation of malignant tumor metastasis. A lack of E-cadherin expression and overexpression of vimentin are hallmarks of EMT. It is well‑known that RhoE, which is associated with regulation of the actin cytoskeleton and migration via alterations in cell motility, regulates the expression of E-cadherin, matrix metalloproteinase-9 (MMP-9) and vimentin. However, it remains to be elucidated whether miR‑200b may alter the molecular behavior of RhoE. The present study aimed to determine whether miR‑200b was able to regulate the EMT of cervical cancer, in order to control metastasis. In addition, the correlation between miR‑200b and RhoE, E‑cadherin and vimentin expression was investigated. Notably, miR‑200b was shown to inhibit the function of RhoE and suppress the EMT of cervical cancer. Furthermore, HeLa cells were transfected with miR‑200b mimics or inhibitors, and the protein expression levels of E‑cadherin, MMP‑9, vimentin and RhoE were subsequently detected. A Transwell assay was also conducted, in order to observe the metastatic ability of the HeLa cells. In addition, a luciferase reporter assay was performed using luciferase reporter vectors containing the full length 3'‑untranslated region (UTR) of RhoE; miR‑200b was able to significantly suppress relative luciferase activity by targeting the 3'‑UTR of RhoE. These results suggested that miR‑200b may markedly inhibit metastatic potential by regulating cell EMT and inhibiting RhoE; therefore, miR-200b may be considered an effective target for the treatment of patients with highly metastatic cervical cancer.

Abstract B41: Specific blocking of miR-17-5p guide strand in triple negative breast cancer cells, without amplifying passenger strand activity

Abstract Conventional wisdom holds that only one of the two strands in a microRNA (miRNA) precursor duplex is selected as the active guide strand. The complementary passenger strand is thought to be inactive. In triple negative breast cancer (TNBC), high levels of the miRNA guide strand called miR-17-5p inhibits ribosomal translation of tumor suppressor genes, such as programmed cell death 4 (PDCD4) or phosphatase and tensin homolog (PTEN). We hypothesized that knocking down the oncogenic microRNA (oncomiR) miR-17-5p might restore the expression levels of PDCD4 and PTEN tumor suppressor proteins, illustrating a route to oligonucleotide therapy of TNBC. Contrary to conventional wisdom, we previously reported that antisense DNA-LNA knockdown of miR-17-5p guide strand reduced PDCD4 and PTEN proteins in human MDA-MB-231 TNBC cells, instead of raising them. Bioinformatics analysis and folding energy calculations revealed that mRNA targets of the miR-17-5p guide strand, such as PDCD4 and PTEN, could also be regulated by the miR-17-3p passenger strand. Due to high sequence homology between the antisense molecules and the miR-17-3p passenger strand, as well as the excess binding sites for the passenger strand on the 3′UTR of PDCD4 and PTEN mRNAs, introducing a miR-17-3p DNA-LNA mimic to knockdown miR-17-5p reduced PDCD4 and PTEN protein expression, instead of raising them. Transfection of miR-17-5p or miR-17-3p RNA mimics into TNBC cells also reduced PDCD4 and PTEN protein levels. To test the hypothesis that miR-17-3p passenger strand can also modulate the same mRNA targets as miR-17-5p, we performed luciferase assays using reporter constructs harboring predicted miR-17-5p and/or miR-17-3p binding sites from the 3′UTR of PDCD4 and PTEN mRNAs. We found that the miR-17-5p mimic lowered the expression of luciferase vectors containing one predicted binding site from the PDCD4 or PTEN 3′UTR domains. However, the miR-17-3p mimic lowered the expression of luciferase vectors containing all four 3′UTR target sites of PDCD4, and two of the six predicted PTEN 3′UTR target sites. In addition, we used luciferase assays to test the hypothesis that antisense DNA-LNA against miR-17-5p mimicked passenger strand miR-17-3p. We found that anti-miR-17-5p DNA-LNA lowered the expression of luciferase reporter vectors containing two of the four predicted PDCD4 3′UTR target sites for miR-17-3p, and one of the six predicted PTEN 3′UTR target sites for miR-17-3p. From these results, we concluded that the miR-17-3p passenger strand might regulate the translation of PDCD4 and PTEN mRNAs, just like the miR-17-5p guide strand. Moreover, the antisense DNA-LNA against miR-17-5p guide strand mimicked the miR-17-3p passenger strand, effectively raising the miR-17-3p concentration in TNBC cells. Our results imply that therapeutic antisense sequences against miRNAs should be designed to target the miRNA strand with the greatest number of putative binding sites in the target mRNAs, while minimizing affinity for the minor strand. Supported by the Department of Biochemistry and Molecular Biology. Conflict of interest: pending PCT/US2015/015681 patent application licensed to Nikita RNA LLC. Citation Format: Yuan-Yuan Jin, Eric Wickstrom. Specific blocking of miR-17-5p guide strand in triple negative breast cancer cells, without amplifying passenger strand activity. [abstract]. In: Proceedings of the Fourth AACR International Conference on Frontiers in Basic Cancer Research; 2015 Oct 23-26; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2016;76(3 Suppl):Abstract nr B41.

The synergistic effect of 5Azadc and TSA on maintenance of pluripotency of chicken ESCs by overexpression of NANOG gene.

NANOG is a transcription factor that functions in embryonic stem cells (ESCs) and a key factor in maintaining pluripotency. Here, we cloned the NANOG gene promoter from the Rugao yellow chicken and constructed a dual luciferase reporter vector to detect its transcriptional activity and analyze the effects of 5-aza-2'-deoxycytidine (5-Azadc) and trichostatin A (TSA) on NANOG promoter activity and ESC pluripotency maintenance in vitro. NANOG transcriptional activity was enhanced when 5-Azadc and TSA were used alone or together, suggesting the possibility of elevated methylation of the CpG island in the NANOG regulatory region. When ESCs were cultured in basic medium with 5-Azadc and TSA in vitro, significantly more cell colonies were maintained in the 5-Azadc + TSA group than in the control group, which had many differentiated cells and few cell colonies after 6d of induction. On the tenth day of induction, the cells in the control group fully differentiated and no cell colonies remained, but many cell colonies were present in the 5-Azadc + TSA group. The expression of NANOG in the cell colonies was confirmed by indirect immunofluorescence. Furthermore, ESCs could be passaged to the 12th generation under 5-Azadc and TSA treatment and maintained their pluripotency. Thus, we showed that 5-Azadc and TSA can effectively maintain chicken ESC pluripotency in vitro by increasing NANOG gene expression.

The identification of hematopoietic-specific regulatory elements for WASp gene expression

Chromosome Conformation Capture (3C) technology was used to identify physical interactions between the proximal Wiskott-Aldrich Syndrome protein (WASp) promoter and its distant DNA segments in Jurkat-T cells. We found that two hematopoietic specific DNase I hypersensitive (DHS) sites (proximal DHS-A, and distal DHS-B) which had high interaction frequencies with the proximal WASp promoter indicating potential regulatory activity for these DHS sites. Subsequently, we cloned several DNA fragments around the proximal DHS-A site into a luciferase reporter vector. Interestingly, no fragments showed enhancer activity, but two fragments exhibited strong silencing activity in Jurkat-T cells. After aligning the chromatin state profiling for hematopoietic and nonhematopoietic cells using the human genome browser (UCSC), we found a 5 kb putative hematopoietic specific enhancer region located 250 kb downstream of the WAS gene. This putative enhancer region contains two hematopoietic cell specific DHS sites. Subsequently, the hematopoietic specific DHS sites enhanced luciferase expression from the proximal WASp promoter in all hematopoietic cells we tested. Finally, using a lentiviral vector stable expression system, the hematopoietic specific-enhancer(s) increased GFP reporter gene expression in hematopoietic cells, and increased WASp gene expression in WASp deficient cells. This enhancer may have the potential to be used in gene therapy for hematological diseases.

Enhancer scanning to locate regulatory regions in genomic loci.

This protocol provides a rapid, streamlined and scalable strategy to systematically scan genomic regions for the presence of transcriptional regulatory regions that are active in a specific cell type. It creates genomic tiles spanning a region of interest that are subsequently cloned by recombination into a luciferase reporter vector containing the simian virus 40 promoter. Tiling clones are transfected into specific cell types to test for the presence of transcriptional regulatory regions. The protocol includes testing of different single-nucleotide polymorphism (SNP) alleles to determine their effect on regulatory activity. This procedure provides a systematic framework for identifying candidate functional SNPs within a locus during functional analysis of genome-wide association studies. This protocol adapts and combines previous well-established molecular biology methods to provide a streamlined strategy, based on automated primer design and recombinational cloning, allowing one to rapidly go from a genomic locus to a set of candidate functional SNPs in 8 weeks.

KDM7A Is Targeted By MiR-155 in Acute Myeloid Leukemia and Impacts Differentiation

Acute myeloid leukemia (AML) is a heterogeneous disease that develops secondary to the acquisition of mutations that disrupt cell differentiation, proliferation and survival. MicroRNAs (miRNAs or miRs) are short non-coding RNA molecules that modulate post-transcriptional gene expression by either cleaving or repressing translation of target mRNA transcripts. Differential expression of miRNAs has been identified in AML and noted to correlate with specific disease characteristics, cytogenetic abnormalities and prognosis.MiR-155 expression is upregulated in both adult and pediatric patients with cytogenetically normal AML (CN-AML) and correlates with adverse clinical outcomes. Specifically, we have shown that high miR-155 expression is associated with an increased incidence of induction chemotherapy failure and inferior overall and event free survival. However, how miR-155 up-regulation contributes mechanistically to adverse clinical outcomes is poorly understood.In prior work, we correlated the expression of predicted or validated miR-155 target genes with miR-155 expression in a gene expression profiling (GEP) dataset of pediatric AML samples. We identified 22 candidates with inversely correlated expression by GEP for further validation in diagnostic bone marrow specimens from children with the highest miR-155 expression levels (n=9) vs. children with the lowest miR-155 expression levels (n=9). Although the expression of miR-155 inversely correlated with 9 target genes, only expression of the putative target KDM7A demonstrated a statistically significant difference in expression between low and high miR-155 expressing cases (p = 0.03).KDM7A is a lysine-specific histone demethylase enzyme that may play a role in regulating differentiation by impacting transcriptional elongation. Computational software programs, i.e. TargetScan, identified two predicted miR-155 binding sites in the KDM7A 3'UTR. To evaluate whether miR-155 directly binds to the KDM7A 3'UTR, we cloned two regions of the KDM7A 3'UTR containing predicted miR-155 binding sequences into luciferase reporter vectors and then mutated the binding sites by site-directed DNA mutagenesis. We validated that both predicted binding sites in KDM7A 3'UTR were direct miR-155 targets using HEK293T cells. Next, we examined the impact of miR-155 overexpression in K562 cells, an acute leukemia cell line that express very low levels of endogenous miR-155, and can be differentiated along the erythroid lineage after hemin exposure. KDM7A RNA expression was decreased 16-fold in miR-155 versus control lentivirally transduced K562 cells as detected by qPCR. KDM7A protein expression was also decreased in miR-155 versus control expressing K562 cells as measured via Western blot. These data demonstrate that KDM7A is a previously uncharacterized target of miR-155.Next, we explored the effect of differential KDM7A expression on cell differentiation, and cell death and apoptosis after exposure to daunorubicin chemotherapy. For this work we used GFP-labeled miR-155 and YFP-labeled KDM7A lentiviral constructs and labeled control constructs. To examine differentiation we used benzidine staining of hemin-exposed K562 cells transduced with empty control vector (ECV), miR-155, KDM7A, or both constructs. The lowest percentage of benzidine staining, consistent with limited erythroid differentiation, was seen in K562 cells with miR-155 overexpression compared to ECV (28.2% vs. 39.8% positive). This effect on blocked erythroid differentiation was fully reversed with overexpression of KDM7A in miR-155 overexpressing cells (41.4% positive). Confirming these observations, we also observed decreased benzidine staining in hemin exposed K562 cells that were transduced with KDM7A shRNA versus control (28.9% versus 42.7%). Together, these data support that KDM7A plays a role in cell differentiation that is in part controlled by miR-155 expression. Preliminary data also support that re-expression of KDM7A in miR-155 overexpressing cells promotes cell death after exposure to daunorubicin. Further work is ongoing. In conclusion, we have identified a new target of miR-155, KDM7A. Our data suggest that KDM7A plays a role in cell differentiation and that decreased KDM7A expression in AML cells that overexpress miR-155 contributes to blocked differentiation, and may also contribute to resistance to chemotherapy. DisclosuresNo relevant conflicts of interest to declare.

Fish IRF3 up-regulates the transcriptional level of IRF1, IRF2, IRF3 and IRF7 in CIK cells.

Interferon Regulatory Factors (IRFs) belong to a family of transcription factor involved in transcriptional regulation of type I IFN and IFN-stimulated genes (ISG) in cells. In the present study, an IRF3 full-length cDNA (termed CiIRF3, JX999055) and its promoter sequence were cloned by homology cloning strategy and genome walking from grass carp (Ctenopharyngodon idella). The full-length cDNA sequence of CiIRF3 is comprised of a 5'UTR (195 bp), a 3'UTR (269 bp) and a largest open reading frame (ORF) of 1377 bp encoding a polypeptide of 458 amino acids. CiIRF3 has a conservative DNA-binding domain (DBD) at N-terminal and a relatively conserved interferon regulatory factors association domain (IAD). Phylogenetic tree analysis indicated that CiIRF3 gathers together with other IRF-3 from higher vertebrates in the same branch. The promoter sequence of CiIRF3 (596 bp) consists of three IRF-E, a C/EBP beta, a NF-kappa B and a TATA-BOX. CiIRF3 was constitutively expressed at low level in different grass carp tissues but was rapidly up-regulated with Poly I:C stimulation. To study the molecular mechanism of CiIRF3 regulating the transcription of IRFs, CiIRF3 was expressed in Escherichia coli BL21 and purified by affinity chromatography with the Ni-NTA His-Bind Resin. Gel mobility shift assays revealed the affinity of CiIRF3 protein with promoters of CiIRF1, CiIRF2, CiIRF3 and CiIRF7 respectively. Then, CIK cells were co-transfected with pcDNA3.1-CiIRF3, pGL3-promotor (pGL3-CiIRF1, pGL3-CiIRF2, pGL3-CiIRF3, pGL3-CiIRF7) and luciferase reporter vector respectively. The cotransfection experiment showed that CiIRF3 increased the promoter activity of CiIRF1, CiIRF2, CiIRF3 and CiIRF7. Furthermore, overexpression of CiIRF3 in CIK cells also up-regulated the expressions of CiIRF1, CiIRF2, CiIRF3 and CiIRF7. So, CiIRF3 can improve the transcriptional level of CiIRF1, CiIRF2, CiIRF3 and CiIRF7.

Human Obesity Associated with an Intronic SNP in the Brain-Derived Neurotrophic Factor Locus.

Brain-derived neurotrophic factor (BDNF) plays a key role in energy balance. In population studies, SNPs of the BDNF locus have been linked to obesity, but the mechanism by which these variants cause weight gain is unknown. Here, we examined human hypothalamic BDNF expression in association with 44 BDNF SNPs. We observed that the minor C allele of rs12291063 is associated with lower human ventromedial hypothalamic BDNF expression (p < 0.001) and greater adiposity in both adult and pediatric cohorts (p values < 0.05). We further demonstrated that the major T allele for rs12291063 possesses a binding capacity for the transcriptional regulator, heterogeneous nuclear ribonucleoprotein D0B, knockdown of which disrupts transactivation by the T allele. Binding and transactivation functions are both disrupted by substituting C for T. These findings provide a rationale for BDNF augmentation as a targeted treatment for obesity in individuals who have the rs12291063 CC genotype.

Change of Ankyrin G Promoter Activity Following Treatment with Sodium Valproate at Different Concentrations

To investigate whether sodium valproate (VPA) directly regulates the activity of Ankyrin G(AnkG) promoter in vitro. The mouse AnkG promoter sequence was identified by comparing both human and mouse AnkG promoter sequences. The promoter was amplified from C57BL/6 mouse genome DNA and cloned into pGL3 Luciferase reporter vector. The Luciferase activity was detected in N2a and 293T cells and then treated with 0,0.5, and 1 mmol/L VPA for 12 h. The transcription activity of AnkG promoter in cells and the activity of VPA-treated Luciferase reporter vector in cells were detected using dual Luciferase reporter assay. The AnkG promoter clone and its expression vector were successfully established, as confirmed by enzyme digestion and sequencing. The AnkG promoter showed high transcription activity in both N2a and 293T cells. The Luciferase activity was significantly induced following 0.5 mmol/L VPA treatment in both N2a and 293T cells. CONCLUSIONS VPA can up-regulate the AnkG expression via directly increasing its transcription activity. Thus, the in vivo AnkG expression may be directly regulated by the VPA at transcriptional level.

Apigenin Inhibits Growth of Breast Cancer Cells: The Role of ERα and HER2/neu

Phytoestrogens are a group of plant-derived compounds with an estrogen-like activity. In mammalians, phytoestrogens bind to the estrogen receptor (ER) and participate in the regulation of cell growth and gene transcription. There are several reports of the cytotoxic effects of phytoestrogens in different cancer cell lines. The aim of this study was to measure the phytoestrogen activity against breast cancer cells with different levels of ER expression and to elucidate the molecular pathways regulated by the leader compound. Methods used in the study include immunoblotting, transfection with a luciferase reporter vector, and a MTT test. We demonstrated the absence of a significant difference between ER+ and ER- breast cancer cell lines in their response to cytotoxic stimuli: treatment with high doses of phytoestrogens (apigenin, genistein, quercetin, naringenin) had the same efficiency in ER-positive and ER-negative cells. Incubation of breast cancer cells with apigenin revealed the highest cytotoxicity of this compound; on the contrary, naringenin treatment resulted in a low cytotoxic activity. It was shown that high doses of apigenin (50 μM) do not display estrogen-like activity and can suppress ER activation by 17β-estradiol. Cultivation of HER2-positive breast cancer SKBR3 cells in the presence of apigenin resulted in a decrease in HER2/neu expression, accompanied by cleavage of an apoptosis substrate PARP. Therefore, the cytotoxic effects of phytoestrogens are not associated with the steroid receptors of breast cancer cells. Apigenin was found to be the most effective phytoestrogen that strongly inhibits the growth of breast cancer cells, including HER2-positive ones.

Novel application of luciferase assay for the in vitro functional assessment of KAL1 variants in three females with septo-optic dysplasia (SOD)

KAL1 is implicated in 5% of Kallmann syndrome cases, a disorder which genotypically overlaps with septo-optic dysplasia (SOD). To date, a reporter-based assay to assess the functional consequences of KAL1 mutations is lacking. We aimed to develop a luciferase assay for novel application to functional assessment of rare KAL1 mutations detected in a screen of 422 patients with SOD.Quantitative analysis was performed using L6-myoblasts stably expressing FGFR1, transfected with a luciferase-reporter vector containing elements of the FGF-responsive osteocalcin promoter.The two variants assayed [p.K185N, p.P291T], were detected in three females with SOD (presenting with optic nerve hypoplasia, midline and pituitary defects). Our novel assay revealed significant decreases in transcriptional activity [p.K185N: 21% (p < 0.01); p.P291T: 40% (p < 0.001)].Our luciferase-reporter assay, developed for assessment of KAL1 mutations, determined that two variants in females with hypopituitarism/SOD are loss-of-function; demonstrating that this assay is suitable for quantitative assessment of mutations in this gene.

ID: 120: Involvement of cyclic AMP signaling pathway in T cell immunoglobulin and mucin domain(TIM)-3 expression by Jurkat T cells

T cell immunoglobulin and mucin domain-3 (TIM-3) plays inhibitory roles in CD4+ T cells leading to low production of interferon- γ . TIM-3 expression increases in T cells of subjects harboring a tumor but the underlying mechanisms remain elusive. Elevated PGE2 levels in tumor-bearing individuals prompted us to hypothesize that PGE2 signaling pathway may affect TIM-3 expression in T cells. We found that PGE2 enhanced TIM-3 protein levels in Jurkat T cells. Also, forskolin, PKA activator and Epac activator which activated PGE2 signaling pathway stimulated TIM-3 expression. Further, forskolin induced TIM-3 mRNA levels in Jurkat T cells, although we did not find the enhanced luciferase activity in response to forskolin using luciferase reporter vectors containing TIM-3 promoter. Our results suggest that cAMP signaling may up-regulate TIM-3 expression in T cells.

Involvement of miR-199a in cisplatin resistance of ovarian cancer cell through modulating expression of mTOR

To study the effect of miR-199a on the sensitivity of OV2008 and C13* cells to cisplatin and investigate its mechanism of action. Real-time polymerase chain reaction(PCR) and Western blot were applied to detect the expression level changes of mammalian target of rapamycin (mTOR) in OV2008 and C13* cells before and after transfecting the cells with the mimics and inhibitor of miR-199a with Lipofectamine 2000.We constructed luciferase reporter vectors of mTOR and then transfected OV2008 cells with the mimics of miR-199a with Lipofectamine 2000 to study the regulation of miR-199a's downstream target genes. The expression level of mTOR was significantly higher in C13* than OV2008 cells (P<0.05). After OV2008 and C13* cells were transfected with the mimics and inhibitor of miR-199a, real-time PCR and Western blot showed that the mimics of miR-199a repressed the expression of mTOR; and the inhibitor of miR-199a promoted the expression of mTOR. After transfecting OV2008 cells with the mimics of miR-199a and luciferase reporter vectors of mTOR, renillaluciferase reporter gene analysis indicated the expression level of mTOR was negatively regulated by miR-199a. miR-199a regulates the sensitivity of ovarian cancer cells to cisplatin through modulating expression of mTOR, and involves in the cisplatin resistance process of ovarian cancer cells.

MiR-139-5p inhibits the biological function of breast cancer cells by targeting Notch1 and mediates chemosensitivity to docetaxel

ObjectivesMiRNA-139 is located at 11q13.4 and it has anti-oncogenic and antimetastatic activity in humans. However, its role in controlling apoptosis, invasion and metastasis and the development of chemosensitivity to docetaxel in breast cancer cells are not fully understood. The aim of this study was to research the biological function of miR-139-5p and the efficacy of chemosensitivity to docetaxel. MethodsMiR-139-5p expression in MCF-7, MCF-7/Doc cells and in selected breast cancer tissue samples was confirmed by real-time PCR; cell viability was analyzed by Cell Counting Kit-8 assay; apoptosis and cell cycle were analyzed by flow cytometry; control of metastasis and invasion of breast cancer cells was measured by transwell assay; expression of Notch1 was measured by western blot; a luciferase reporter vector was constructed to identify the miR-139-5p target gene. ResultsMiR-139-5p was significantly down-regulated in breast cancer cells. MiR-139-5p inhibits the viability of breast cancer cells. MiR-139-5p induces apoptosis, causes cell cycle arrest in S phase, inhibits migration and invasion in breast cancer cells, however, MiR-139-5p play the opposite role in docetaxel-induced breast cancer cells. ConclusionsMiR-139-5p not only attenuated the development of breast cancer cells but also mediated drug-resistance by regulating the expression of the downstream target gene Notch1.

Systematic Screening of Promoter Regions Pinpoints Functional Cis-Regulatory Mutations in a Cutaneous Melanoma Genome

With the recent discovery of recurrent mutations in the TERT promoter in melanoma, identification of other somatic causal promoter mutations is of considerable interest. Yet, the impact of sequence variation on the regulatory potential of gene promoters has not been systematically evaluated. This study assesses the impact of promoter mutations on promoter activity in the whole-genome sequenced malignant melanoma cell line COLO-829. Combining somatic mutation calls from COLO-829 with genome-wide chromatin accessibility and histone modification data revealed mutations within promoter elements. Interestingly, a high number of potential promoter mutations (n = 23) were found, a result mirrored in subsequent analysis of TCGA whole-melanoma genomes. The impact of wild-type and mutant promoter sequences were evaluated by subcloning into luciferase reporter vectors and testing their transcriptional activity in COLO-829 cells. Of the 23 promoter regions tested, four mutations significantly altered reporter activity relative to wild-type sequences. These data were then subjected to multiple computational algorithms that score the cis-regulatory altering potential of mutations. These analyses identified one mutation, located within the promoter region of NDUFB9, which encodes the mitochondrial NADH dehydrogenase (ubiquinone) 1 beta subcomplex 9, to be recurrent in 4.4% (19 of 432) of TCGA whole-melanoma exomes. The mutation is predicted to disrupt a highly conserved SP1/KLF transcription factor binding motif and its frequent co-occurrence with mutations in the coding sequence of NF1 supports a pathologic role for this mutation in melanoma. Taken together, these data show the relatively high prevalence of promoter mutations in the COLO-829 melanoma genome, and indicate that a proportion of these significantly alter the regulatory potential of gene promoters. Genomic-based screening within gene promoter regions suggests that functional cis-regulatory mutations may be common in melanoma genomes, highlighting the need to examine their role in tumorigenesis.

Abstract 3071: MicroRNA-486 (miR-486) promotes invasion by targeting RECK in nasopharyngeal carcinoma cells

Abstract Nasopharyngeal carcinoma (NPC) is a common cancer in Taiwanese and people living in the southeastern region of China. In order to investigate NPC pathogenesis, our laboratory has previously established NPC-TW01 cell line, which was derived from a Taiwanese NPC patient. We also established a NPC-TW01N1 cell line, which was derived from the NPC xenograft in SCID mouse. Both NPC-TW01 and NPC-TW01N1 cell lines have an identical DNA profile (STR). NPC-TW01N1 cell line has higher malignant potency than NPC-TW01 line. For example, the proliferation and invasion capabilities of NPC-TW01N1 line were higher than that of NPC-TW01 line. When we used microRNA microarray to compare the endogenous microRNA expression profiles between NPC-TW01 and NPC-TW01N1 lines, the miR-486, miR-200a and other miRNAs showed higher expression in NPC-TW01N1 cell. Transfection of exogenous miR-486 or anti-miR-486 into NPC-TW01 cells or NPC-TW01N1 cells revealed that miR-486 involves in the regulation of NPC cell progression and invasion. To determine whether miR-486 targeted gene involves in progression and invasion, we analyzed microRNA targeted gene database, Ingenuity pathway databases, and cDNA expression microarrays from miR-486 transfected cells. We found that the RECK gene is one of miR-486 candidate targeted genes that involves in NPC cell progression and invasion. We used pmirGLO luciferase reporter vector assays to demonstrate that miR-486 directly targets RECK 3′ UTR. When we transfected miR-486 or RECK siRNA into NPC cells, we found that they can accelerate tumor progression and invasion. It is concluded that miR-486 and RECK genes maybe potential targets for NPC therapy. Citation Format: Chin-Tarng Lin, Cheng-Der Wu. MicroRNA-486 (miR-486) promotes invasion by targeting RECK in nasopharyngeal carcinoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3071. doi:10.1158/1538-7445.AM2015-3071

MiR-18a Can Regulate Chemotherapy Sensitivity of Leukemia Cell HL-60 to VP-16 and VCR by Targeting ATM

To investigate the regulatory effects of miR-18a on chemotherapeutic sensitivity of leukemia cell HL-60 to VP-16 and VCR, and explore its molecular mechamism. The HL-60 PC DNA3.1-miR-18A cell line with stably overexpressing miR-18a was constructed and their sensitivity to VP-16 and VCR was detected. The luciferase reporter vector of ATM 3'UTR region was constructed and the targeting effect of miR-18a on ATM was identified. The expression level of ATM in HL-60 cells overexpressing miR-18a was detected by Western blot. The seusitivity of HL-60 cells with knockdown of ATM to VP-16 and VCR was detected by CCK-8 method. The ATM expression level in HL-60 cells with stably overexpression miR-18a after transfection of miR-18a inhibitor was detected by using Western blot and the sensitivity changes of these HL-60 cells to VP-16 and BCR were detected. After overexpression of miR-18a, the viability of HL-60 cells treated with VP-16 and VCR of same concentration decreased; the detectiion of luciferase activity showed that the miR-18a could inhitit activity of luciferase reporter vector of ATM; the expression level of ATM in HL-60 cells was down-regulated after transfection with miR-18a; the cell viability decreased when HL-60 cells were treated with VP-16 and VCR after knockdown of ATM; the expression level of ATM was up-regulated and the cell viability decreased when HL-60 cells were treated with VP-16 and VCR after transfection with miR-18a inhibitor. The miR-18a can regulated the sensitivity of leukemia HL-60 cells to VP-16 and VCR by targeting ATM.

Adrenal Steroid Metabolites Accumulating in Congenital Adrenal Hyperplasia Lead to Transactivation of the Glucocorticoid Receptor.

Patients with congenital adrenal hyperplasia (CAH) are often clinically less severely affected by cortisol deficiency than anticipated from their enzymatic defect. We hypothesize that adrenal steroid hormone precursors that accumulate in untreated or poorly controlled CAH have glucocorticoid activity and partially compensate for cortisol deficiency. We studied the in vitro effects of 17-hydroxyprogesterone (17OHP), progesterone (P), 21-deoxycortisol (21DF), and androstenedione (Δ4) on the human glucocorticoid receptor (hGR). Competitive binding assays were performed in HeLa cells. Nuclear translocation of the hGR was studied by transfection of COS-7 cells with a GFP-tagged hGR and fluorescence microscopy. Transactivation assays were performed in COS-7 cells and in HEK 293 cells after cotransfection with hGR and luciferase reporter vectors using a dual luciferase assay. 17OHP, P, and 21DF are able to bind to the hGR with binding affinities of 24-43% compared with cortisol. Δ4 has a low binding affinity. Incubation with 21DF led to complete nuclear translocation of the hGR, whereas treatment with 17OHP or P resulted in partial nuclear translocation. 21DF transactivated the hGR with an EC50 approximately 6 times the EC50 of cortisol. 17OHP and P transactivated the hGR with EC50s of more than 100 times the EC50 of cortisol. No hGR transactivation was detected after incubation with Δ4. 21DF, 17OHP, and P are able to bind, translocate, and transactivate the hGR in vitro and thus may have glucocorticoid activity. 21DF might have a clinically relevant agonistic effect on the hGR and could potentially partially compensate the cortisol deficiency in CAH patients.