Chemical induced pathognomonic features observed in human vitiligo are mediated through miR-2909 RNomics pathway.

BACKGROUND: Chemicals like Monobenzyl Ether of Hydroquinone (MBEH) and 4-Tertiary Butyl Phenol (4-TBP) have been widely recognized to induce clinical lesions that resemble vitiligo, but exact molecular pathway through which these chemicals initiate vitiligo is still far from clear. OBJECTIVES: Since vitiligo is widely considered as an autoimmune disease, this study was an attempt to understand miR-2909 RNomics in vitiligo pathogenesis using MBEH treated primary melanocytes as an archetype cellular model because MBEH causes pathological features indistinguishable from clinical vitiligo. METHODS: Primary melanocytes were treated with MBEH and 4-TBP and the role of miR-2909 RNomics at transcriptional and translational level was explored through qRT-PCR, western blot analysis, flow cytometry, immunocytochemistry, immunohistochemistry and in silico binding affinities. 4 mm punch biopsies were also obtained from lesional sites of vitiligo patients to validate the results observed in cell culture experiments. RESULTS: MBEH induced miR-2909 RNomics led to downregulation of MITF, TYR, TYRP1, and TYRP2 leading to decreased melanin synthesis which in turn is a characteristic trait of vitiligo. On the other hand, 4-TBP increased TGF-ß which also has the intrinsic capacity to downregulate MITF leading to decreased melanin synthesis and thereby initiation of vitiligo. CONCLUSION: Based upon our results we propose a molecular pathway which has the inherent capacity to resolve the mechanism through which these chemicals may induce vitiligo. This mechanism was also found to be involved in the lesional biopsies of vitiligo patients. These results could be exploited in better understanding the pathogenesis as well as in treatment of vitiligo.

Mitochondrial respiration is restricted by miR-2909 within human melanocytes.

Most of the cancer types in general and melanoma in particular exhibit mitochondrial dysfunction leading to the Warburg effect. Our present study stemmed from the observation that human A-375 and melanoma B16 cells displayed overexpression of a novel micro-RNA, miR-2909, shown in our earlier studies to be involved in aerobic glycolysis. Consequently, our study attempts to demonstrate the role of miR-2909 in the regulation of mitochondrial function within human melanocytes. Based upon such a study, we hypothesize that mitochondrial dysfunction observed in melanomas may result from deregulated miR-2909 expression within such cells.

Tumorigenic PVT-1 gene locus is governed by miR-2909 RNomics.

Genomic regulation and functional significance of PVT-1 gene locus, in the MYC-driven cancers, has remained enigmatic ever since its discovery. With the present study, an attempt is made to establish that cellular AATF genome encoded miR-2909 RNomics pathway involving crucial genes coding for KLF4, Deptor, mTORC1, STAT3, and p53 has the inherent capacity to ensure sustained co-amplification of PVT-1 gene locus together with c-Myc gene. Based upon these results, we propose that miR-2909 RNomics pathway may play a crucial role in the regulation of tumorigenic PVT-1 gene locus.

Human cellular mitochondrial remodelling is governed by miR-2909 RNomics.

BACKGROUND: There exists a general recognition of the fact that mitochondrial remodelling as a result of aerobic glycolysis ensures human somatic cells to revert to a more primitive-form exhibiting stem-like phenotype. The present study is an attempt to demonstrate that miR-2909 RNomics within human peripheral blood mononuclear cells (PBMCs) has the inherent capacity to re-program these cells to exhibit mitochondrial remodelling paralleled by aerobic glycolysis together with intracellular lipid inclusions. Such re-programmed PBMCs also expressed genes having ability to sustain their de-differentiation state and survival. MATERIAL AND METHODS: Human PBMCs were programed to ectopically express miR-2909. Expression levels of genes including glucose transporter-1 (Glut-1), hexokinase (HK), hypoxia inducia factor-1 (HIF-1α), c-Myc, p53,mechanistic target of rapamycin complex (mTORC1), polycombcomplex protein (Bmi-1), Notch,Nanog,Tie-2, Oct-4,CD59, p53, CD34, B-cell lymphoma-2 (Bcl2),sterol regulatory element-binding protein2 (SREBP2), peroxisome proliferator-activated receptor gamma (PPARγ) nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (Tfam), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) within miR-2909 expression vector transfected human PBMCs as well as PBMCs transfected with control vector containing scrambled sequence after 48h post-transfection using RT-qPCR and cellular ultrastructural features induced by miR-2909 ectopic expression were observed using transmission electron microscopy and morphometric analysis of an electron micrograph. RESULTS: Ectopic expression of miR-2909 within human PBMCs resulted in their reprogramming into stem-like phenotype indicated by mitochondrial globular shaped coupled with cristae-poor morphology. Nuclear to cytoplasmic ratio (N/C), quantification of ATP levels, GSSG/GSH ratio, mitochondrial cytochrome c oxidase activity, secreted lactate concentrations, activity of antioxidant enzymes, levels of esterified cholesterol and triglycerides and flow-cytometric detection of apoptosis confirmed the compromised nature of mitochondrial function induced by ectopic miR-2909 expression in human PBMCs. CONCLUSION: Based upon these results we propose that AATF gene-encoded miR-2909 may act as an epigenetic switch for cellular aerobic-glycolysis to ensure de-differentiation.

Cancer cells govern miR-2909 exosomal recruitment through its 3'-end post-transcriptional modification.

It is widely believed that selective packaging of nucleic acids, especially microRNAs, into exosomes secreted by the cancer cells not only ensures their growth and survival but also helps in the escape from immune surveillance. Keeping in view the fact that human cellular miR-2909 has emerged to regulate genes involved in oncogenesis and immunity, the present study was addressed to reveal the nature of miR-2909 expression within cancer cells of different tissue origin and its incorporation into exosomes secreted by these cells. Post-transcriptional modification, especially 3'-end adenylation and uridylation of miR-2909, exerts opposing effects that may contribute to direct its sorting into exosomes secreted by cancer cells. Our study also revealed that selective partitioning of adenosine kinase, between cancer cells and their secreted exosomes, may be responsible for the nature of post-transcriptional modification of miR-2909 observed within these cells.

An androgen-regulated miR-2909 modulates TGFß signalling through AR/miR-2909 axis in prostate cancer.

In recent years, microRNAs (miRNAs) have emerged as promising biomarkers for PCa diagnosis and prognosis. miR-2909 is a novel miRNA that can regulate immunogenomics and oncogenomics. The present study investigated the role of miR-2909 in the pathogenesis of PCa and the potential signalling pathways through which it operates. We have identified miR-2909 as a novel mediator of androgen/androgen receptor (AR) signalling that enhances the proliferation potential of PCa cells and assists in cancer survival under reduced androgen levels. Our results revealed that miR-2909 down regulates TGFBR2 by targeting its 3'-UTR sequence. We also observed that miR-2909 over-expression attenuated TGFß-mediated SMAD3 activation, cell growth inhibition and apoptosis. Moreover, miR-2909 modulated the expression of p21CIP, c-MYC and CCND1 through TGFß signalling. Importantly, we also demonstrated that miR-2909 and AR regulates each other's expression resulting in a positive feedback loop. In conclusion, our study suggests that miR-2909 is an androgen-inducible miRNA that exerts its oncogenic effects by attenuating the tumor-suppressive effects of TGFß signalling.

miR-2909 regulates ISGylation system via STAT1 signalling through negative regulation of SOCS3 in prostate cancer.

One of the well-document strategies adopted by tumour cells for progression is to evade immune surveillance mechanisms. An understanding of the tight interaction between immunity and progression of cancer can provide novel treatment options for different malignancies including prostate cancer (PCa). Here, we have shown that AATF genome encoded miR-2909, known to play role both in immunity and cancer upregulates various interferon stimulating genes (ISGs) including ISGylation system through STAT1. Our results revealed that miR-2909 up-regulates STAT1 through negative regulation of SOCS3 and not through up-regulation of Type 1 interferon (IFN) production. It was observed that inhibition of ISGylation reduced the proliferation potential of PCa cells. Furthermore, androgens were found to negatively regulate ISGylation in LNCaP cells through androgen receptor signalling independently of miR-2909. TGF-ß mediated SMAD3 signalling was also seen to be suppressed by miR-2909 through induction of SMAD7 via enhanced STAT1 expression. Collectively, these studies suggest that miR-2909 could play a vital role in prostate carcinogenesis through modulation of ISGylation system and TGFß signalling via STAT1.

APOBEC3G governs the generation of truncated AATF protein to ensure oncogenic transformation.

The oncogenic potential of Apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3G (APOBEC3G) was recently appreciated by the finding that revealed its ability to downregulate Kruppel-like factor 4 (KLF4) gene translation through its affinity for 3'UTR of KLF4 mRNA. Keeping in view the fact that KLF4 is known to repress apoptosis antagonizing transcription factor (AATF) gene expression, the present study employed stem cells as archetype model to explore the effect of APOBEC3G over-expression upon AATF gene expression within these cells as well as on the genes involved in oncogenic transformation. Such a study revealed that APOBEC3G had the ability to bind AATF mRNA within its third exon to facilitate the generation of truncated 23 kDa AATF translation product which, in turn, had the inherent capacity to be the crucial mediator of APOBEC3G induced oncogenic transformation within such cells.

APOBEC3G has the ability to programme T cell plasticity.

Recently Apolipoprotein B mRNA editing enzyme, Catalytic Polypeptide-like 3G (APOBEC3G) biology has assumed importance because of its role in oncogenesis. In this context, the present study was addressed to understand the immune-modulatory role of APOBEC3G through its effect upon the T-cell plasticity phenomenon. Such an attempt revealed that APOBEC3G has the inherent capacity to regulate genes coding for STAT3, NF-κB, CCL5, IL-6, IL-4, IFN-γ, IL-10 and IL-17 coupled with downregulation of Treg cells within human peripheral blood mononuclear cells (PBMCs) without any noticeable influence upon CD4(+) and CD8(+) cell number. On the basis of these findings, we propose that APOBEC3G has the ability to induce T cell plasticity and modulate immune response.

DNA Ploidy and S-phase Fraction Analysis in Paediatric B-cell Acute Lymphoblastic Leukemia Cases: a Tertiary Care Centre Experience.

DNA ploidy is an important prognostic parameter in paediatric B-ALL, but the significance of the S-phase fraction is unclear. In present study, DNA ploidy was assessed in 40 pediatric B-ALL cases by flow cytometry. The DI (DNA index) and percentage of cells in S-phase were calculated using Modfit software. Aneuploidy was noted in 26/40 (65%) cases. A DI of 1.10-1.6 (hyperdiploidy B) was noted in 20/40 (50%) and 6/40 (15%) had a DI>1.60 (triploid and tetraploid range). Some 14/40 (35%) cases had a diploid DI between 0.90-1.05. None of the cases had a DI <0.90 (hypodiploid) or in the 1.06-1.09 (hyperdiploid A) range. The mean S-phase fraction was 2.6%, with 24/40 (60%) having low and 16/40 (40%) high S-phase fractions. No correlation was noted with standard ALL risk and treatment response factors with DI values or S-phase data, except for a positive correlation of low S-phase with high NCI risk category (p=0.032). Overall frequency of hyperdiploidy in our cohort of B-ALL patients was very high (65%). No correlation between hyperdiploidy B and low TLC or common B-phenotype was observed in our study as 42% cases with DI 1.10-1.6 had TLC> 50 x 109 and 57.1% CD 10 negativity. The study also highlighted that S-phase fraction analysis does not add any prognostic information and is not a useful parameter for assessment in ALL cases. However, larger studies with long term outcome analysis are needed to derive definitive conclusions.

APOBEC3G governs to ensure cellular oncogenic transformation.

The oncogenic potential of APOBEC3G gene was recently appreciated by the finding that revealed inhibitory influence of APOBEC3G upon micro-RNA mediated repression of the gene responsible for hepatic metastasis. Here we report for the first time that sustained APOBEC3G expression is the characteristic trait exhibited by various cancer cells of different tissue origins as well as APOBEC3G represses cellular gene coding for tumor suppressor KLF4 by binding to its mRNA. This phenomenon was paralleled by the sustained expression of the cellular SP1 which ensured overexpression of genes coding for c-myc, Bmi-1, BCL-2 and MDM2 coupled with downregulation of tumor suppressor p53 thereby creating a favorable situation for oncogenic transformation.

Mitochondrial uncoupling protein (UCP2) gene expression is regulated by miR-2909.

Reversible decoupling of glycolysis from aerobic-respiration has been widely recognized to be a crucial step in tailoring immune response by the human cells. In this context, the study reported here revealed for the first time that cooperativity between Apoptosis Antagonizing Transcription Factor (AATF) mRNA and miR-2909 within cellular AATF RNome ensures the regulation of mitochondrial uncoupling protein 2 (UCP2) expression in a cyclic fashion and this phenomenon is substantiated when the immune cells face high glucose threat.

Microdissecting the role of microRNAs in the pathogenesis of prostate cancer.

MicroRNAs (miRNAs) are naturally occurring, small, non-coding RNA molecules that post-transcriptionally regulate the expression of a large number of genes involved in various biological processes, either through mRNA degradation or through translation inhibition. Since the discovery of miRNAs, a vast amount of research has implicated the deregulated expression of miRNAs in different malignancies, including prostate cancer (PCa). Different miRNA expression profiles are reportedly associated with the development, progression, and emergence of castration-resistant PCa (CRPC), suggesting their use in the diagnosis, prognosis, and development of anti-cancer treatment models directed against this disease. However, before their exploitation in terms of therapeutics, a thorough understanding and in-depth mechanistic studies of these miRNAs and the gene networks they orchestrate are necessary for ascertaining their definitive role in the development and progression of PCa. This review attempts to extensively summarize the current knowledge of aberrantly expressed miRNAs and their mode of action in PCa, while highlighting the existing discrepancies and future research warranted.

Short-Term Adjuvant Therapy with Terminalia arjuna Attenuates Ongoing Inflammation and Immune Imbalance in Patients with Stable Coronary Artery Disease: In Vitro and In Vivo Evidence.

The present study evaluated the cardioprotective effects of Terminalia arjuna on classical and immuno-inflammatory markers in coronary artery disease (CAD) as an adjuvant therapy. One hundred sixteen patients with stable CAD were administered placebo/T. arjuna (500 mg twice a day) along with medications in a randomized, double-blind clinical trial. To understand the specificity and efficacy of T. arjuna, we evaluated its effect through microarray and in silico analysis in few representative samples. Data was further validated via real-time PCR (n = 50) each at baseline, 3 months, and 6 months, respectively. rIL-18 cytokine was used to induce inflammation in vitro to compare its effects with atorvastatin. T. arjuna significantly down-regulated TG, VLDL-C, and immuno-inflammatory markers in stable CAD versus placebo-treated subjects. Microarray and pathway analysis of a few samples from T. arjuna/placebo-treated groups and real-time PCR validation further confirmed our observations. Our data demonstrate the anti-inflammatory and immunomodulatory effects of T. arjuna that may attenuate ongoing inflammation and immune imbalance in medicated CAD subjects.

Functional nature of a novel mutant CYLD observed in pediatric lymphoblastic B-cell leukemia.

The Deubiquitinating enzyme, Cylindromatosis (CYLD), has been established as a crucial regulator of B-cells. The present study was addressed to identify the nature of CYLD-dependent RNomics in patients of pediatric age group with B-ALL. The study revealed the presence of a novel mutant CYLD of 55 kDa in these patients. The mutant CYLD displayed its ability to restrict the cells in G2 phase of cell cycle, down-regulate PLK-1 and block the nuclear translocation of BCL3. Based upon these results, we propose that this mutant CYLD has the capacity to act as a differential marker characteristic of B-cell lymphoblastic leukemia. Pediatr Blood Cancer 2015;62:1066-1069. © 2015 Wiley Periodicals, Inc.

High glucose-induced human cellular immune response is governed by miR-2909 RNomics.

Regulation of NFkB family member RelA translocation by tumour suppressor genes encoding p53 and KLF4, has been widely recognized as the critical for human peripheral blood mononuclear cells (PBMCs) to meet their energy requirement for tailoring their immune response against any perceived threat. Our study was addressed to understand as to how human PBMCs respond to high glucose threat in terms of their genomics-directed immune response. The results of such a study revealed for the first time that NFkB induced miR-2909 RNomics is crucial for the regulation of RelA translocation within human PBMCs exposed to high glucose thereby enabling these epigenetically programmed cells to tailor immune response involving genes coding for CCL5; IFN-γ and IL-17. Based upon these results an attempt was also made to propose a mechanistic pathway that links high glucose induced cellular miR-2909 RNomics with the genes involved in energy metabolism and immune response.

MALT1 induced immune response is governed by miR-2909 RNomics.

The paracaspase mucosa-associated lymphoid tissue 1 (MALT1) has been widely recognized to play crucial role in lymphocyte activation, development and the generation of lymphomas through the modulation of innate and adaptive immune responses. Our results reported here provide evidence for the first time to support the view that MALT1 exerts its effect upon immune response involving genes coding for retinoic acid-inducible gene 1 (RIG1); interferon-ß (IFN-ß); apo-lipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3G (APOBEC3G); IFN-γ; chemokine (C-C motif) ligand 5 (CCL5) and interleukin-17 (IL-17) through the initiation of cellular miR-2909 RNomics. This ensures sustained expression of specificity protein 1 (SP1)-dependent regulation of genes that in-turn governs MALT1 induced immune response. Based upon these results, a mechanistic-pathway is proposed that links the epigenomic-interplay between MALT1 and miR-2909.

Cellular proteolytic modification of tumor-suppressor CYLD is critical for the initiation of human T-cell acute lymphoblastic leukemia.

There exists a general recognition of the fact that post translational modification of CYLD protein through proteolytic cleavage by MALT-1 results in sustained cellular NF-kB activity which is conspicuously found to be associated with cancer in general and hematological malignancies in particular. The present study was directed to understand the contribution of MALT-1 and deubiquitinase CYLD to the initiation of T-cell acute lymphoblastic leukemia (T-ALL). Such a study revealed for the first time that the 35kDa CYLD cleaved factor generated by MALT-1 mediated proteolytic cleavage was conspicuously present in human T- ALL subjects of pediatric age group. Further, over-expression of this 35kDa CYLD factor within normal human peripheral blood mononuclear cells had the inherent capacity to program the genome of these cells resulting in T-cell lineage ALL. Based upon these results, we propose that MALT1 inhibitors may be of crucial importance in the treatment of T-ALL subjects of pediatric age group.

Oncogenic nature of a novel mutant AATF and its interactome existing within human cancer cells.

Since apoptosis presents a natural defense in cancer development, the anti-apoptotic factor AATF/Che-1 has emerged as a crucial 'Epigenomic-Switch'. We have tried to understand the double-edged nature of AATF, showing for the first time the conspicuous existence of an aberrant AATF/Che-1 transcriptome encoding for 23 kDa mutant AATF protein, which evolves its unique interactome within human cancer cells derived from different tissue origins. This mutant AATF along with its interactome consisting of SP1, DNMT3B and Par-4 ensures cancer cell DNA methylation required for down-regulation of tumor suppressor genes. Hence, the proposed mutant AATF interactome-based pathway can have the inherent ability to ensure human cells become and remain cancerous.

miR-2909-mediated regulation of KLF4: a novel molecular mechanism for differentiating between B-cell and T-cell pediatric acute lymphoblastic leukemias.

BACKGROUND: microRNAs (miRNAs) play both oncogenic and oncostatic roles in leukemia. However, the molecular details underlying miRNA-mediated regulation of their target genes in pediatric B- and T-cell acute lymphoblastic leukemias (ALLs) remain unclear. The present study investigated the relationship between miR-2909 and Kruppel-like factor 4 (KLF4), and its functional relevance to cell cycle progression and immortalization in patients with pediatric ALL. METHODS: Elevated levels of miR-2909 targeted the tumor suppressor gene KLF4 in pediatric B-cell, but not pediatric T-cell ALL, as detected by pMIR-GFP reporter assay. Expression levels of genes including apoptosis-antagonizing transcription factor (AATF), MYC, B-cell lymphoma (BCL3), P21CIP, CCND1 and SP1 in B- and T-cells from patients with pediatric ALL were compared with control levels using real-time quantitative reverse transcription polymerase chain reaction, western blotting, and reporter assays. RESULTS: We identified two novel mutations in KLF4 in pediatric T-ALL. A mutation in the 3' untranslated region of the KLF4 gene resulted in loss of miR-2909-mediated regulation, while mutation in its first or third zinc-finger motif (Zf1/Zf3) rendered KLF4 transcriptionally inactive. This mutation was a frameshift mutation resulting in alteration of the Zf3 motif sequence in the mutant KLF4 protein in all pediatric T-ALL samples. Homology models, docking studies and promoter activity of its target gene P21CIP confirmed the lack of function of the mutant KLF4 protein in pediatric T-ALL. Moreover, the inability of miR-2909 to regulate KLF4 and its downstream genes controlling cell cycle and apoptosis in T-cell but not in B-ALL was verified by antagomiR-2909 transfection. Comprehensive sequence analysis of KLF4 identified the predominance of isoform 1 (~55 kDa) in most patients with pediatric B-ALL, while those with pediatric T-ALL expressed isoform 2 (~51 kDa). CONCLUSIONS: This study identified a novel miR-2909-KLF4 molecular axis able to differentiate between the pathogeneses of pediatric B- and T-cell ALLs, and which may represent a new diagnostic/prognostic marker.