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Biology subjects

Parma, B.

Publications and source records attributed to Parma, B..

5 recordsLinked to original sources

A dual role for GLI3 signaling in neural crest development

Neural crest cells (NCCs) are a multipotent cell population that undergo specification, epithelial-to-mesenchymal transition, migration, and differentiation into a plethora of cell types. A wealth of studies across various embryonic model systems have established dogma as to the molecular mechanisms and signaling cascades that contribute to NCC development. While Wnt, FGF, and BMP signaling pathways have well-established and essential roles in several aspects of NCC development, the Hedgehog (HH) signaling pathway has received limited attention for any specific role in this process. Herein, we propose two distinct, temporal roles for the transcription factor GLI3 in NCC development. Gli3, and other members of the HH pathway, were robustly co-expressed with established NCC induction and specification markers in chick, mouse, and human embryonic stem cell derived NCCs. Early knock-down of GLI3 reduced expression of key markers of NCC specification and conditional knock-out of Gli3 post-specification specifically impaired the ability of cranial NCCs to differentiate into ectomesenchymal derivatives. Together, these results demonstrate dual, novel roles for GLI3 in early NCC specification and later in cranial NCC differentiation. Summary StatementGLI3 plays distinct temporal roles in neural crest specification and differentiation into ectomesenchymal derivatives.

developmental biology↗

Growth-factor ligand functionalization enhances cellular and in vivo uptake of DNA nanodevices

Epidermal Growth Factor (EGF) and Transforming Growth Factor beta (TGF-{beta}) are two important classes of growth factor that regulates cell growth, cell proliferation, differentiation, immune responses, and extracellular matrix generation. Using a short peptide-based ligand coupled to DNA nanocages, we present the enhanced internalization of a receptor-mediated peptide-DNA nanocage. We used here tdDNA as a delivery vehicle. Our study in cellular and in vivo showed excellent internalization, cell growth, and inhibition. We expect that a tdDNA-modified receptor-binding peptides could become a valuable scaffold for use as a cellular programming and regenerative material.

bioengineering↗

Metabolic breakdown of non-small cell lung cancers by mitochondrial HSPD1 targeting

The identification of novel targets is of paramount importance to develop more effective drugs and improve the treatment of non-small cell lung cancer (NSCLC), the leading cause of cancer-related deaths worldwide. Since cells alter their metabolic rewiring during tumorigenesis and along cancer progression, targeting key metabolic players and metabolism-associated proteins represents a valuable approach with a high therapeutic potential. Metabolic fitness relies on the functionality of heat shock proteins (HSPs), molecular chaperones that facilitate the correct folding of metabolism enzymes and their assembly in macromolecular structures. Here, we show HSPD1 (HSP60) as a survival gene ubiquitously expressed in NSCLC and associated with poor patients prognosis. HSPD1 knockdown or its chemical disruption by the small molecule KHS101 induces a drastic breakdown of oxidative phosphorylation, and suppresses cell proliferation both in vitro and in vivo. By combining drug profiling with transcriptomics and through a whole-genome CRISPR/Cas9 screen, we demonstrate that HSPD1-targeted anti-cancer effects are dependent on OXPHOS and validated molecular determinants of KHS101 sensitivity, in particular, the creatine-transporter SLC6A8 and the subunit of the cytochrome c oxidase complex COX5B. These results highlight mitochondrial metabolism as an attractive target and HSPD1 as a potential theranostic marker for developing therapies to combat NCSLC. SignificanceHSPD1 elimination or disruption interferes with NSCLC metabolic activity causing a strong OXPHOS-dependent energetic breakdown, which the cancer cells fail to overcome, highlighting HSPD1 as a potential theranostic marker for improving lung cancer therapy.

cancer biology↗

Thymidylate synthase drives the phenotypes of epithelial-to-mesenchymal transition in non-small cell lung cancer

BackgroundEpithelial-to-mesenchymal transition (EMT) enhances motility, stemness and chemoresistance of carcinomas and is an important determinant of metastasis. Little is known about how various pathways coordinate to elicit EMTs different functional aspects. Even lesser has been studied in this context in non-small cell lung cancer (NSCLC), where EMT is a key event during early tumorigenesis. Thymidylate synthase (TS), a proliferation enzyme, has been previously correlated with EMT transcription factor ZEB1 in NSCLC and is associated with resistance against anti-folate chemotherapy. In this study we establish a functional correlation between TS, EMT, chemotherapy and metastasis and identify a network that might propel the TS mediated EMT phenotype. MethodsPublished datasets were analysed to evaluate significance of TS in NSCLC fitness and prognosis. mCherry based promoter reporter assay was used to sort Calu-1 and A549 NSCLC cells in TSHIGH and TSLOW. Metastatic potential of TS knock-down was assayed in syngeneic C57BL/6 mice. ResultsLow TS levels were prognostic and predicted chemotherapy response. NSCLC cell lines with higher TS promoter activity were more mesenchymal-like. RNA-seq from these cells, and shRNA mediated TS knocked down cells, identified EMT as one of the most differentially regulated pathways. EMT transcription factors HOXC6 and HMGA2 were identified as upstream regulator of TS whereas, AXL, SPARC and FOSL1 were identified as downstream effectors. TS knock-down reduced the metastatic colonisation in vivo. ConclusionThese results establish the role of TS as a theranostic NSCLC marker integrating survival, chemo-resistance and EMT, and identifies a regulatory network that could be exploited to target EMT-driven NSCLC.

cancer biology↗

Exploration of endogenous miRNA-200b/c activity and regulation through a functional dual fluorescence reporter

Since their discovery, microRNAs (miRNA)s have been widely studied in almost every aspect of biology and medicine, leading to the identification of important gene regulation circuits and cellular mechanisms. However, investigations are generally focused on the analysis of their downstream targets and biological functions in overexpression and knockdown approaches, while miRNAs endogenous levels and activity remain poorly understood. Here, we used the cellular plasticity-regulating process of epithelial-to-mesenchymal transition (EMT) as a model to show the efficacy of a fluorescent sensor to separate cells with distinct EMT signatures, based on miR-200b/c activity. The system was further combined with a CRISPR-Cas9 screening platform to unbiasedly identify miR-200b/c upstream regulating genes. The sensor allows to infer miRNAs fundamental biological properties, as profiling of sorted cells indicated miR-200b/c as a molecular switch between EMT differentiation and proliferation, and suggested a role for metabolic enzymes in miR-200/EMT regulation. Analysis of miRNAs endogenous levels and activity could lead to a better understanding of their biological role in physiology and disease.

molecular biology↗