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  Yorkie dependent transcriptional network promotes tumor growth.

  Studies in Drosophila and other tumor models have revealed cancer promoting signaling interactions and transcriptional addictions in tumors cells. The Hippo pathway effector, Yorkie (Yki) is a key mediator of such interactions and presents an attractive opportunity to study transcriptional dependencies in cancer cells. The RasV12 scrib-/- tumor mosaic model is well-established and shows activation of oncogenic Ras in the background of impaired apical-basal polarity. This model is widely used study molecular mechanisms and signaling events downstream of the oncogenic Ras and Ras-mediated Yorkie (Yki) activation in RasV12, scrib-/- tumor cells. Previously, we have shown that in RasV12, scrib-/- cells Wingless (Wg), Caspases (e.g., the initiator caspase Dronc) and JNK are activated to promote tumorigenesis through their non-apoptotic roles. Amongst these, Wg/Wnt pathway is known to act via canonical and non-canonical pathways during development and cancer, and interact with Yki to promote cancer growth. Genetic epistasis showed that Wg acts upstream of Caspases, JNK and Yki, and downregulation of Wg reduced tumor growth by downregulation of Caspases, JNK and Yki reporters. Our goal is to further understand how the two evolutionarily conserved signaling pathways i.e., Hippo and Wingless crosstalk and interact with each other to regulate tumor growth. To understand this intricate wiring of Wingless-Yorkie during tumor growth and invasion, we will use the RasV12, scrib-/- tumor model in Drosophila imaginal discs. Preliminary data showed that wg transcriptional reporters are upregulated in RasV12, scrib-/- cells, suggesting that increased accumulation of Wg may be due to increased transcription. In other contexts, wg is shown as a transcriptional target of Yki. Therefore, we will test for (a) the effects of Yorkie protein, the main effector molecule of Hippo pathway, on wg transcription and expression of other Wg pathway components by reporter assays, and qRT-PCR- based approaches, and (b) feedback interactions that promote tumorigenesis using genetic epistasis-, and immunohistochemistry-based approaches. Here, we present our progress on the organization of the molecular network involving Wingless and Yorkie.

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  ZFP36 Ring Finger Protein Like 1 (ZFP36L1) knockdown significantly reduced lipopolysaccharide-induced proinflammatory cytokine expression

  CCCH-Type Zinc finger proteins(CCCH-ZFP) are small protein domains that are structurally maintained by zinc ions. Zinc ions coordinate the protein structure in a tetrahedral geometry by biding cysteines or cysteines and histidine amino acids. The unique structure of CCCH-ZFP enables it to interact with a wide variety of molecules such as DNA, RNA, or cellular proteins and thus modulate several cellular processes including host immune response and virus replication. For the current study, we screened 68 CCCH type zinc finger proteins using a literature search for their antiviral as well as immunomodulatory properties along with their expression in human cells and their potential to interact with SARS-CoV-2 RNA using RNA-Protein Interaction Prediction (RPISeq) software. Using this strategy, we selected ZFP36 Ring Finger Protein Like 1 (ZFP36L1) which scored a higher point to interact with SARS-CoV-2 RNA and modulate host immune response as compared to other CCCH type zinc finger proteins. Before measuring the effect of ZFP36L1 expression on SARS-CoV-2 replication, we aimed to determine the effect of ZFP36L1 expression on host innate immune response. We overexpressed or knockdown ZFP36L1 in HEK 293T cells as well as in Raw 264.7 macrophage. Our preliminary results showed that knocking down ZFP36L1 significantly reduced lipopolysaccharide (LPS) mediated tumor necrosis factor-alpha(TNF alpha) expression (p<0.05). However, we still need to measure the effect of ZFP36L1 overexpression or knockdown on LPS induced TNF alpha at earlier timepoints.