The GATA transcriptional program dictates cell fate equilibrium to establish the maternal-fetal exchange interface and fetal development.

The placenta establishes a maternal-fetal exchange interface to transport nutrients and gases between the mother and the fetus. Establishment of this exchange interface relies on the development of multinucleated syncytiotrophoblasts (SynT) from trophoblast progenitors, and defect in SynT development often leads to pregnancy failure and impaired embryonic development. Here, we show that mouse embryos with conditional deletion of transcription factors GATA2 and GATA3 in labyrinth trophoblast progenitors (LaTPs) have underdeveloped placenta and die by ~embryonic day 9.5. Single-cell RNA sequencing analysis revealed excessive accumulation of multipotent LaTPs upon conditional deletion of GATA factors. The GATA factor-deleted multipotent progenitors were unable to differentiate into matured SynTs. We also show that the GATA factor-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. Loss of either GATA2 or GATA3 in cytotrophoblast-derived human trophoblast stem cells (human TSCs) drastically inhibits SynT differentiation potential. Identification of GATA2 and GATA3 target genes along with comparative bioinformatics analyses revealed that GATA factors directly regulate hundreds of common genes in human TSCs, including genes that are essential for SynT development and implicated in preeclampsia and fetal growth retardation. Thus, our study uncovers a conserved molecular mechanism, in which coordinated function of GATA2 and GATA3 promotes trophoblast progenitor-to-SynT commitment, ensuring establishment of the maternal-fetal exchange interface.

Differential carbonic anhydrase activities control EBV-induced B-cell transformation and lytic cycle reactivation.

Epstein-Barr virus (EBV) contributes to ~1% of all human cancers including several B-cell neoplasms. A characteristic feature of EBV life cycle is its ability to transform metabolically quiescent B-lymphocytes into hyperproliferating B-cell blasts with the establishment of viral latency, while intermittent lytic cycle induction is necessary for the production of progeny virus. Our RNA-Seq analyses of both latently infected naïve B-lymphocytes and transformed B-lymphocytes upon lytic cycle replication indicate a contrasting expression pattern of a membrane-associated carbonic anhydrase isoform CA9, an essential component for maintaining cell acid-base homeostasis. We show that while CA9 expression is transcriptionally activated during latent infection model, lytic cycle replication restrains its expression. Pharmacological inhibition of CA-activity using specific inhibitors retards EBV induced B-cell transformation, inhibits B-cells outgrowth and colony formation ability of transformed B-lymphocytes through lowering the intracellular pH, induction of cell apoptosis and facilitating degradation of CA9 transcripts. Reanalyses of ChIP-Seq data along with utilization of EBNA2 knockout virus, ectopic expression of EBNA2 and sh-RNA mediated knockdown of CA9 expression we further demonstrate that EBNA2 mediated CA9 transcriptional activation is essential for EBV latently infected B-cell survival. In contrast, during lytic cycle reactivation CA9 expression is transcriptionally suppressed by the key EBV lytic cycle transactivator, BZLF1 through its transactivation domain. Overall, our study highlights the dynamic alterations of CA9 expression and its activity in regulating pH homeostasis act as one of the major drivers for EBV induced B-cell transformation and subsequent B-cell lymphomagenesis.

Hippo signaling cofactor, WWTR1, at the crossroads of human trophoblast progenitor self-renewal and differentiation.

Healthy progression of human pregnancy relies on cytotrophoblast (CTB) progenitor self-renewal and its differentiation toward multinucleated syncytiotrophoblasts (STBs) and invasive extravillous trophoblasts (EVTs). However, the underlying molecular mechanisms that fine-tune CTB self-renewal or direct its differentiation toward STBs or EVTs during human placentation are poorly defined. Here, we show that Hippo signaling cofactor WW domain containing transcription regulator 1 (WWTR1) is a master regulator of trophoblast fate choice during human placentation. Using human trophoblast stem cells (human TSCs), primary CTBs, and human placental explants, we demonstrate that WWTR1 promotes self-renewal in human CTBs and is essential for their differentiation to EVTs. In contrast, WWTR1 prevents induction of the STB fate in undifferentiated CTBs. Our single-cell RNA sequencing analyses in first-trimester human placenta, along with mechanistic analyses in human TSCs revealed that WWTR1 fine-tunes trophoblast fate by directly regulating WNT signaling components. Importantly, our analyses of placentae from pathological pregnancies show that extreme preterm births (gestational time ≤28 wk) are often associated with loss of WWTR1 expression in CTBs. In summary, our findings establish the critical importance of WWTR1 at the crossroads of human trophoblast progenitor self-renewal versus differentiation. It plays positive instructive roles in promoting CTB self-renewal and EVT differentiation and safeguards undifferentiated CTBs from attaining the STB fate.

Proteasomal inhibition triggers viral oncoprotein degradation via autophagy-lysosomal pathway.

Epstein-Barr virus (EBV) nuclear oncoprotein EBNA3C is essential for B-cell transformation and development of several B-cell lymphomas particularly those are generated in an immuno-compromised background. EBNA3C recruits ubiquitin-proteasome machinery for deregulating multiple cellular oncoproteins and tumor suppressor proteins. Although EBNA3C is found to be ubiquitinated at its N-terminal region and interacts with 20S proteasome, the viral protein is surprisingly stable in growing B-lymphocytes. EBNA3C can also circumvent autophagy-lysosomal mediated protein degradation and subsequent antigen presentation for T-cell recognition. Recently, we have shown that EBNA3C enhances autophagy, which serve as a prerequisite for B-cell survival particularly under growth deprivation conditions. We now demonstrate that proteasomal inhibition by MG132 induces EBNA3C degradation both in EBV transformed B-lymphocytes and ectopic-expression systems. Interestingly, MG132 treatment promotes degradation of two EBNA3 family oncoproteins-EBNA3A and EBNA3C, but not the viral tumor suppressor protein EBNA3B. EBNA3C degradation induced by proteasomal inhibition is partially blocked when autophagy-lysosomal pathway is inhibited. In response to proteasomal inhibition, EBNA3C is predominantly K63-linked polyubiquitinated, colocalized with the autophagy-lysosomal fraction in the cytoplasm and participated within p62-LC3B complex, which facilitates autophagy-mediated degradation. We further show that the degradation signal is present at the first 50 residues of the N-terminal region of EBNA3C. Proteasomal inhibition reduces the colony formation ability of this important viral oncoprotein, induces apoptotic cell death and increases transcriptional activation of both latent and lytic gene expression which further promotes viral reactivation from EBV transformed B-lymphocytes. Altogether, this study offers rationale to use proteasome inhibitors as potential therapeutic strategy against multiple EBV associated B-cell lymphomas, where EBNA3C is expressed.

EBNA3C facilitates RASSF1A downregulation through ubiquitin-mediated degradation and promoter hypermethylation to drive B-cell proliferation.

EBV latent antigen 3C (EBNA3C) is essential for EBV-induced primary B-cell transformation. Infection by EBV induces hypermethylation of a number of tumor suppressor genes, which contributes to the development of human cancers. The Ras association domain family isoform 1A (RASSF1A) is a cellular tumor suppressor, which regulates a broad range of cellular functions, including apoptosis, cell-cycle arrest, mitotic arrest, and migration. However, the expression of RASSF1A is lost in many human cancers by epigenetic silencing. In the present study, we showed that EBNA3C promoted B-cell transformation by specifically suppressing the expression of RASSF1A. EBNA3C directly interacted with RASSF1A and induced RASSF1A degradation via the ubiquitin-proteasome-dependent pathway. SCFSkp2, an E3-ubiquitin ligase, was recruited by EBNA3C to enhance RASSF1A degradation. Moreover, EBNA3C decreased the transcriptional activity of RASSF1A promoter by enhancing its methylation through EBNA3C-mediated modulation of DNMTs expression. EBNA3C also inhibited RASSF1A-mediated cell apoptosis, disrupted RASSF1A-mediated microtubule and chromosomal stability, and promoted cell proliferation by upregulating Cyclin D1 and Cyclin E expression. Our data provides new details, which sheds light on additional mechanisms by which EBNA3C can induce B-cell transformation. This will also facilitate the development of novel therapeutic approaches through targeting of the RASSF1A pathway.

Identification of two novel thiophene analogues as inducers of autophagy mediated cell death in breast cancer cells.

Natural compounds isolated from different medicinal plants remain one of the major resources of anticancer drugs due to their enormous chemical diversity. Studies suggested therapeutic potential for various tanshinones, key bioactive lipophilic compounds from the root extracts of Salvia miltiorrhiza Bunge, against multiple cancers including breast carcinoma. We designed, synthesized and evaluated anti-cancer properties of a series of condensed and doubly condensed furophenanthraquinones of tanshinone derivatives on two breast cancer lines - MCF7 and MDA-MB-231. We identified two thiophene analogues - compounds 48 and 52 with greater anti-proliferative efficiency (~4 fold) as compared to the natural tanshinones. Mechanistically, we showed that both compounds induced autophagy mediated cell death and partial but significant restoration of cell death in the presence of autophagy inhibitor further supported this notion. Both compounds transcriptionally activated several autophagy genes responsible for autophagosome formation along with two death regulators - GADD34 and CHOP for inducing cell death. Altogether, our studies provide strong evidence to support compounds 48 and 52 as promising leads for further development as anticancer agents through modulating autophagy mechanism.

Mechanisms of B-Cell Oncogenesis Induced by Epstein-Barr Virus.

Epstein-Barr virus (EBV) is a ubiquitous gammaherpesvirus which asymptomatically infects the majority of the world population. Under immunocompromised conditions, EBV can trigger human cancers of epithelial and lymphoid origin. The oncogenic potential of EBV is demonstrated by in vitro infection and transformation of quiescent B cells into lymphoblastoid cell lines (LCLs). These cell lines, along with primary infection using genetically engineered viral particles coupled with recent technological advancements, have elucidated the underlying mechanisms of EBV-induced B-cell lymphomagenesis.

Helicobacter pylori helicase loader protein Hp0897 shows unique functions of N- and C-terminal regions.

Helicase loaders are required for the loading of helicases at the vicinity of replication origins. In Helicobacter pylori, Hp0897 has been shown to be a potential helicase loader for replicative helicase (HpDnaB) although it does not show any sequence homology with conventional DnaC like helicase loader proteins. Therefore, it is important to investigate the in vivo role of Hp0897 and structure-function analysis with respect to domain mapping of Hp0897 and HpDnaB. Although HporiC is divided into oriC1 and oriC2, the latter has been assigned as functional origin based on loading of initiator protein HpDnaA. Using chromatin immunoprecipitation (ChIP) experiment, we show preferential binding of Hp0897 at oriC2 over oriC1 like HpDnaA highlighting its helicase loader function in vivo. Furthermore, we generated series of deletion mutants for HpDnaB and Hp0897 that enabled us to map the domains of interaction between these two proteins. Interestingly, the C-terminal domain of Hp0897 (Hp0897CTD) shows stronger interaction with HpDnaB over the N-terminal region of Hp0897 (Hp0897NTD). Similar to the full-length protein, Hp0897CTD also stimulates the DNA binding activity of HpDnaB. Furthermore, overexpression of Hp0897 full-length protein in H. pylori leads to an elongated cell phenotype. While the overexpression of Hp0897CTD does not show a phenotype of cell elongation, overexpression of Hp0897NTD shows extensive cell elongation. These results highlight the possible role of Hp0897CTD in helicase loading and Hp0897NTD's unique function linked to cell division that make Hp0897 as a potential drug target against H. pylori.

EBV Nuclear Antigen 3C Mediates Regulation of E2F6 to Inhibit E2F1 Transcription and Promote Cell Proliferation.

Epstein-Barr virus (EBV) is considered a ubiquitous herpesvirus with the ability to cause latent infection in humans worldwide. EBV-association is evidently linked to different types of human malignancies, mainly of epithelial and lymphoid origin. Of interest is the EBV nuclear antigen 3C (EBNA3C) which is critical for EBV-mediated immortalization. Recently, EBNA3C was shown to bind the E2F1 transcription regulator. The E2F transcription factors have crucial roles in various cellular functions, including cell cycle, DNA replication, DNA repair, cell mitosis, and cell fate. Specifically, E2F6, one of the unique E2F family members, is known to be a pRb-independent transcription repressor of E2F-target genes. In our current study, we explore the role of EBNA3C in regulating E2F6 activities. We observed that EBNA3C plays an important role in inducing E2F6 expression in LCLs. Our study also shows that EBNA3C physically interacts with E2F6 at its amino and carboxy terminal domains and they form a protein complex in human cells. In addition, EBNA3C stabilizes the E2F6 protein and is co-localized in the nucleus. We also demonstrated that both EBNA3C and E2F6 contribute to reduction in E2F1 transcriptional activity. Moreover, E2F1 forms a protein complex with EBNA3C and E2F6, and EBNA3C competes with E2F1 for E2F6 binding. E2F6 is also recruited by EBNA3C to the E2F1 promoter, which is critical for EBNA3C-mediated cell proliferation. These results demonstrate a critical role for E2F family members in EBV-induced malignancies, and provide new insights for targeting E2F transcription factors in EBV-associated cancers as potential therapeutic intervention strategies.

Epigenetic silencing of tumor suppressor genes during in vitro Epstein-Barr virus infection.

DNA-methylation at CpG islands is one of the prevalent epigenetic alterations regulating gene-expression patterns in mammalian cells. Hypo- or hypermethylation-mediated oncogene activation, or tumor suppressor gene (TSG) silencing mechanisms, widely contribute to the development of multiple human cancers. Furthermore, oncogenic viruses, including Epstein-Barr virus (EBV)-associated human cancers, were also shown to be influenced by epigenetic modifications on the viral and cellular genomes in the infected cells. We investigated EBV infection of resting B lymphocytes, which leads to continuously proliferating lymphoblastoid cell lines through examination of the expression pattern of a comprehensive panel of TSGs and the epigenetic modifications, particularly methylation of their regulatory sequences. EBV infection of primary B lymphocytes resulted in global transcriptional repression of TSGs through engagement of hypermethylation. Therefore, CpG methylation profiles of TSGs may be used as a prognostic marker as well as development of potential therapeutic strategies for controlling acute infection and EBV-associated B-cell lymphomas.

Epstein-Barr virus essential antigen EBNA3C attenuates H2AX expression.

Epstein-Barr virus (EBV) latent antigen EBNA3C is implicated in B-cell immortalization and linked to several B-cell malignancies. Deregulation of H2AX can induce genomic instability with increased chromosomal aberrations, which ultimately leads to tumorigenesis. Here we demonstrated that EBNA3C can attenuate H2AX expression at the transcript and protein levels. A reduction of total H2AX levels was clearly observed upon infection of primary B cells with wild-type EBV but not with EBNA3C knockout recombinant EBV. H2AX also interacted with EBNA3C through its N-terminal domain (residues 1 to 100). Furthermore, H2AX mutated at Ser139 failed to interact with EBNA3C. Luciferase-based reporter assays also revealed that the binding domain of EBNA3C is sufficient for transcriptional inhibition of the H2AX promoter. EBNA3C also facilitated H2AX degradation through recruitment of components of the ubiquitin proteasome pathway. We further demonstrated that knockdown of H2AX in lymphoblastoid cell lines (LCLs) led to the upregulation of the Bub1 oncoprotein and downregulated expression of p53. Overall, our study provides additional insights into EBV-associated B-cell lymphomas, which are linked to the regulation of the DNA damage response system in infected cells. The importance of these insights are as follows: (i) EBNA3C downregulates H2AX expression at the protein and transcript levels in epithelial cells, B cells, and EBV-transformed LCLs, (ii) EBNA3C binds with wild-type H2AX but not with the Ser139 mutant of H2AX, (iii) the N terminus (residues 1 to 100) of EBNA3C is critical for binding to H2AX, (iv) localization of H2AX is predominantly nuclear in the presence of EBNA3C, and (v) H2AX knocked down in LCLs led to enhanced expression of Bub1 and downregulation of the tumor suppressor p53, which are both important for driving the oncogenic process.

The EBV Latent Antigen 3C Inhibits Apoptosis through Targeted Regulation of Interferon Regulatory Factors 4 and 8.

Epstein-Barr virus (EBV) is linked to a broad spectrum of B-cell malignancies. EBV nuclear antigen 3C (EBNA3C) is an encoded latent antigen required for growth transformation of primary human B-lymphocytes. Interferon regulatory factor 4 (IRF4) and 8 (IRF8) are transcription factors of the IRF family that regulate diverse functions in B cell development. IRF4 is an oncoprotein with anti-apoptotic properties and IRF8 functions as a regulator of apoptosis and tumor suppressor in many hematopoietic malignancies. We now demonstrate that EBNA3C can contribute to B-cell transformation by modulating the molecular interplay between cellular IRF4 and IRF8. We show that EBNA3C physically interacts with IRF4 and IRF8 with its N-terminal domain in vitro and forms a molecular complex in cells. We identified the Spi-1/B motif of IRF4 as critical for EBNA3C interaction. We also demonstrated that EBNA3C can stabilize IRF4, which leads to downregulation of IRF8 by enhancing its proteasome-mediated degradation. Further, si-RNA mediated knock-down of endogenous IRF4 results in a substantial reduction in proliferation of EBV-transformed lymphoblastoid cell lines (LCLs), as well as augmentation of DNA damage-induced apoptosis. IRF4 knockdown also showed reduced expression of its targeted downstream signalling proteins which include CDK6, Cyclin B1 and c-Myc all critical for cell proliferation. These studies provide novel insights into the contribution of EBNA3C to EBV-mediated B-cell transformation through regulation of IRF4 and IRF8 and add another molecular link to the mechanisms by which EBV dysregulates cellular activities, increasing the potential for therapeutic intervention against EBV-associated cancers.

H2AX phosphorylation is important for LANA-mediated Kaposi's sarcoma-associated herpesvirus episome persistence.

The DNA damage response (DDR) of host cells is utilized by a number of viruses to establish and propagate their genomes in the infected cells. We examined the expression of the DDR genes during Kaposi's sarcoma-associated herpesvirus (KSHV) infection of human peripheral blood mononuclear cells (PBMCs). The genes were mostly downregulated, except H2AX, which was upregulated during infection. H2AX is important for gammaherpesvirus infectivity, and its phosphorylation at serine 139 is crucial for maintenance of latency during mouse gamma-herpesvirus 68 (MHV-68) infection. We now also observed phosphorylation of H2AX at serine 139 during KSHV infection. H2AX is a histone H2A isoform shown to interact with the latency-associated nuclear antigen (LANA) encoded by KSHV. Here, we show that LANA directly interacted with H2AX through domains at both its N and C termini. The phosphorylated form of H2AX (γH2AX) was shown to colocalize with LANA. Chromatin immunoprecipitation (ChIP) assays showed that a reduction in H2AX levels resulted in reduced binding of LANA with KSHV terminal repeats (TRs). Binding preferences of H2AX and γH2AX along the KSHV episome were examined by whole-episome ChIP analysis. We showed that γH2AX had a higher relative binding activity along the TR regions than that of the long unique region (LUR), which highlighted the importance of H2AX phosphorylation during KSHV infection. Furthermore, knockdown of H2AX resulted in decreased KSHV episome copy number. Notably, the C terminus of LANA contributed to phosphorylation of H2AX. However, phosphorylation was not dependent on the ability of LANA to drive KSHV-infected cells into S-phase. Thus, H2AX contributes to association of LANA with the TRs, and phosphorylation of H2AX is likely important for its increased density at the TRs.

EBNA3C-mediated regulation of aurora kinase B contributes to Epstein-Barr virus-induced B-cell proliferation through modulation of the activities of the retinoblastoma protein and apoptotic caspases.

Epstein-Barr virus (EBV) is an oncogenic gammaherpesvirus that is implicated in several human malignancies, including Burkitt's lymphoma (BL), posttransplant lymphoproliferative disease (PTLD), nasopharyngeal carcinoma (NPC), and AIDS-associated lymphomas. Epstein-Barr nuclear antigen 3C (EBNA3C), one of the essential EBV latent antigens, can induce mammalian cell cycle progression through its interaction with cell cycle regulators. Aurora kinase B (AK-B) is important for cell division, and deregulation of AK-B is associated with aneuploidy, incomplete mitotic exit, and cell death. Our present study shows that EBNA3C contributes to upregulation of AK-B transcript levels by enhancing the activity of its promoter. Further, EBNA3C also increased the stability of the AK-B protein, and the presence of EBNA3C leads to reduced ubiquitination of AK-B. Importantly, EBNA3C in association with wild-type AK-B but not with its kinase-dead mutant led to enhanced cell proliferation, and AK-B knockdown can induce nuclear blebbing and cell death. This phenomenon was rescued in the presence of EBNA3C. Knockdown of AK-B resulted in activation of caspase 3 and caspase 9, along with poly(ADP-ribose) polymerase 1 (PARP1) cleavage, which is known to be an important contributor to apoptotic signaling. Importantly, EBNA3C failed to stabilize the kinase-dead mutant of AK-B compared to wild-type AK-B, which suggests a role for the kinase domain in AK-B stabilization and downstream phosphorylation of the cell cycle regulator retinoblastoma protein (Rb). This study demonstrates the functional relevance of AK-B kinase activity in EBNA3C-regulated B-cell proliferation and apoptosis.

The RBP-Jκ binding sites within the RTA promoter regulate KSHV latent infection and cell proliferation.

Kaposi's sarcoma-associated herpesvirus (KSHV) is tightly linked to at least two lymphoproliferative disorders, primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD). However, the development of KSHV-mediated lymphoproliferative disease is not fully understood. Here, we generated two recombinant KSHV viruses deleted for the first RBP-Jκ binding site (RTA(1st)) and all three RBP-Jκ binding sites (RTA(all)) within the RTA promoter. Our results showed that RTA(1st) and RTA(all) recombinant viruses possess increased viral latency and a decreased capability for lytic replication in HEK 293 cells, enhancing colony formation and proliferation of infected cells. Furthermore, recombinant RTA(1st) and RTA(all) viruses showed greater infectivity in human peripheral blood mononuclear cells (PBMCs) relative to wt KSHV. Interestingly, KSHV BAC36 wt, RTA(1st) and RTA(all) recombinant viruses infected both T and B cells and all three viruses efficiently infected T and B cells in a time-dependent manner early after infection. Also, the capability of both RTA(1st) and RTA(all) recombinant viruses to infect CD19+ B cells was significantly enhanced. Surprisingly, RTA(1st) and RTA(all) recombinant viruses showed greater infectivity for CD3+ T cells up to 7 days. Furthermore, studies in Telomerase-immortalized human umbilical vein endothelial (TIVE) cells infected with KSHV corroborated our data that RTA(1st) and RTA(all) recombinant viruses have enhanced ability to persist in latently infected cells with increased proliferation. These recombinant viruses now provide a model to explore early stages of primary infection in human PBMCs and development of KSHV-associated lymphoproliferative diseases.

E2F1 mediated apoptosis induced by the DNA damage response is blocked by EBV nuclear antigen 3C in lymphoblastoid cells.

EBV latent antigen EBNA3C is indispensible for in vitro B-cell immortalization resulting in continuously proliferating lymphoblastoid cell lines (LCLs). EBNA3C was previously shown to target pRb for ubiquitin-proteasome mediated degradation, which facilitates G1 to S transition controlled by the major transcriptional activator E2F1. E2F1 also plays a pivotal role in regulating DNA damage induced apoptosis through both p53-dependent and -independent pathways. In this study, we demonstrate that in response to DNA damage LCLs knocked down for EBNA3C undergo a drastic induction of apoptosis, as a possible consequence of both p53- and E2F1-mediated activities. Importantly, EBNA3C was previously shown to suppress p53-induced apoptosis. Now, we also show that EBNA3C efficiently blocks E2F1-mediated apoptosis, as well as its anti-proliferative effects in a p53-independent manner, in response to DNA damage. The N- and C-terminal domains of EBNA3C form a stable pRb independent complex with the N-terminal DNA-binding region of E2F1 responsible for inducing apoptosis. Mechanistically, we show that EBNA3C represses E2F1 transcriptional activity via blocking its DNA-binding activity at the responsive promoters of p73 and Apaf-1 apoptosis induced genes, and also facilitates E2F1 degradation in an ubiquitin-proteasome dependent fashion. Moreover, in response to DNA damage, E2F1 knockdown LCLs exhibited a significant reduction in apoptosis with higher cell-viability. In the presence of normal mitogenic stimuli the growth rate of LCLs knockdown for E2F1 was markedly impaired; indicating that E2F1 plays a dual role in EBV positive cells and that active engagement of the EBNA3C-E2F1 complex is crucial for inhibition of DNA damage induced E2F1-mediated apoptosis. This study offers novel insights into our current understanding of EBV biology and enhances the potential for development of effective therapies against EBV associated B-cell lymphomas.

Exploring machine learning and statistical approach techniques for landslide susceptibility mapping in Siwalik Himalayan Region using geospatial technology.

Landslides are a natural threat that poses a severe risk to human life and the environment. In the Kumaon mountains region in Uttarakhand (India), Nainital is among the most vulnerable areas prone to landslides inflicting harm to livelihood and civilization due to frequent landslides. Developing a landslide susceptibility map (LSM) in this Nainital area will help alleviate the probability of landslide occurrence. GIS and statistical-based approaches like the certainty factor (CF), information value (IV), frequency ratio (FR) and logistic regression (LR) are used for the assessment of LSM. The landslide inventories were prepared using topography, satellite imagery, lithology, slope, aspect, curvature, soil, land use and land cover, geomorphology, drainage density and lineament density to construct the geodatabase of the elements affecting landslides. Furthermore, the receiver operating characteristic (ROC) curve was used to check the accuracy of the predicting model. The results for the area under the curves (AUCs) were 87.8% for logistic regression, 87.6% for certainty factor, 87.4% for information value and 84.8% for frequency ratio, which indicates satisfactory accuracy in landslide susceptibility mapping. The present study perfectly combines GIS and statistical approaches for mapping landslide susceptibility zonation. Regional land use planners and natural disaster management will benefit from the proposed framework for landslide susceptibility maps.

Dysregulation of DNA epigenetic modulators during prostate carcinogenesis in an eastern Indian patient population: Prognostic implications.

The role of epigenetic alteration in prostate cancer pathogenesis was reported. We aimed to analyze dysregulation of DNA methylase (DNA methyl transferase/DNMT) and demethylase (ten eleven translocase/TET) and the associated interplay between them during prostate tumorigenesis. Promoter methylation and RNA/protein expression of selected DNMT and TETs were analysed in normal prostate, benign prostatic hyperplasia (BPH), and prostate cancer (PCa). Genomic 5-hydroxymethylcytosine (5hmC) level was detected and correlated with DNMT and TET proteins. Clinicopathological association of molecular data was done. Our data revealed a very low frequency of promoter methylation for DNMT1 (5-3% and high frequency for TET1 (22-38%), TET2 (68-90 %), and TET3 (43-32 %) in BPH and PCa. The promoter methylation of DNMT1 (p = 0.019) showed a significantly decreasing trend, while that of TET1 (p = 0.0005) and TET2 (p < 0.0001) showed an increasing trend from normal prostate to BPH to PCa, indicating their epigenetic dysregulation during prostate tumorigenesis. RNA/protein overexpression of DNMT1 and reduced expression of TET1 and TET2 in PCa compared to BPH were associated with the promoter methylation status of genes. The 5hmC level was significantly lower in PCa than in BPH and correlated negatively with DNMT1 but positively with TET1 and TET2 proteins, suggesting dysregulation of DNA methylase and de-methylase activities during prostate tumorigenesis. Lastly, tumors having methylated TET1 and TET2 promoters showed advanced clinicopathological features (a higher PSA level/Gleason score) and increased risk of bone metastasis. In conclusion, DNMT1 upregulation and epigenetic silencing of TET1 and TET2 was seen during PCa development. TET1 and TET2 promoter methylation has prognostic importance.

Epstein-Barr virus nuclear antigen 3C stabilizes Gemin3 to block p53-mediated apoptosis.

The Epstein-Barr nuclear antigen 3C (EBNA3C), one of the essential latent antigens for Epstein-Barr virus (EBV)-induced immortalization of primary human B lymphocytes in vitro, has been implicated in regulating cell proliferation and anti-apoptosis via interaction with several cellular and viral factors. Gemin3 (also named DDX20 or DP103) is a member of DEAD RNA helicase family which exhibits diverse cellular functions including DNA transcription, recombination and repair, and RNA metabolism. Gemin3 was initially identified as a binding partner to EBNA2 and EBNA3C. However, the mechanism by which EBNA3C regulates Gemin3 function remains unclear. Here, we report that EBNA3C directly interacts with Gemin3 through its C-terminal domains. This interaction results in increased stability of Gemin3 and its accumulation in both B lymphoma cells and EBV transformed lymphoblastoid cell lines (LCLs). Moreover, EBNA3C promotes formation of a complex with p53 and Gemin3 which blocks the DNA-binding affinity of p53. Small hairpin RNA based knockdown of Gemin3 in B lymphoma or LCL cells remarkably attenuates the ability of EBNA3C to inhibit the transcription activity of p53 on its downstream genes p21 and Bax, as well as apoptosis. These findings provide the first evidence that Gemin3 may be a common target of oncogenic viruses for driving cell proliferation and anti-apoptotic activities.