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Biology subjects

Belova, E.

Publications and source records attributed to Belova, E..

5 recordsLinked to original sources

Sensory neurons inhibit invadopodia and metastasis via direct CGRP-RAMP1-cAMP signaling to cancer cells

Breast cancer is globally the most common cancer among women. Although the five-year survival rate exceeds 80% for patients with localized disease, it drops to approximately 30% once metastasis occurs, underscoring the urgent need to define mechanisms that drive metastatic progression. Breast is a highly innervated organ and most of its innervation is sensory. However, whether sensory neurons can directly impact breast cancer cells remains an understudied topic. Here, we show that mammary tumors have increased CGRP sensory innervation. Using our novel microfluidic Device for Cancer cell-Axon Interaction Testing (DACIT), we demonstrate that the presence of axons strongly inhibits ECM-degrading ability of cancer cells. The sensory neuron secretome suppresses assembly and function of invadopodia, which are cancer cell protrusions controlling ECM degradation, and essential for intravasation and metastasis. We identify calcitonin gene-related peptide (CGRP) as the key component of the sensory neuron secretome responsible for the inhibitory effect. CGRP signaling occurs through the CRLR/RAMP1 receptor complex expressed by breast cancer cells, inducing a rapid increase in intracellular cAMP levels in breast cancer cells, followed by an increase in RhoC activity and suppression of invadopodia and ECM degradation. Loss of RAMP1 function enhances 3D spheroid invasion, cancer cell motility in vivo and significantly increases the number and the size of lung metastatic foci. Consistently, in silico analyses of both mouse and human RNASeq data point to a link between increasingly invasive subtypes with a gradual decrease in expression of RAMP1 and CRLR. To validate in silico findings, we compare RAMP1 expression in the patient breast tumors with adjacent normal tissues, confirming the invasive breast tumors have reduced levels of RAMP1. Together, our findings identify a protective role for the paracrine CGRP signaling in limiting breast cancer invasion and metastasis. We also demonstrate how cancer cells circumvent CGRP inhibition by suppressing RAMP1 expression, highlighting CGRP-RAMP1-cAMP axis as a potential therapeutic target in breast cancer.

cancer biology↗

Cell cycle- and EMT-dependent expression of Filip1L controls invadopodia in breast cancer cells

Invadopodia are actin- and protease-rich membrane structures that enable cancer cells to degrade extracellular matrix (ECM). Invadopodia activity is cell cycle-dependent, but how their regulation across the cell cycle is influenced by epithelial-to-mesenchymal transition (EMT) remains unclear. We show that as the EMT progresses, cell engagement in invadopodia-mediated ECM degradation shits from G2 phase in Early E/M cells to G1 phase in Late E/M or M cells. Using bulk mRNA sequencing of Early- versus Late- E/M cells sorted by cell cycle phase, we identified FILIP1L as an EMT- and cell cycle-regulated candidate whose expression peaks in the invasive phase of each cell state: G2 in Early E/M cells and G1 in Late E/M cells. We next demonstrated that FILIP1L is a novel invadopodia component, whose loss increases ECM degradation while impairing migration and 3D invasion. In mouse models, FILIP1L KD tumors develop fewer metastatic colonies, suggesting that FILIP1L supports productive invasion by coordinating between invadopodia and migratory cell states. FILIP1L expression increases with EMT progression and correlates with poor outcomes in breast cancer patients. Together, these findings identify a previously unrecognized link between EMT, cell cycle and invadopodia and establish FILIP1L as the key regulator of this process.

cancer biology↗

Attenuation of neural responses in subthalamic nucleus during internally guided voluntary movements in Parkinson's disease

The proposed models of segregated functional loops describe the organization of motor control over externally triggered (ET) and internally guided (IG) movements. The dopamine deficiency in Parkinsons disease (PD) is considered to cause a disturbance in the functional loop regulating IG movements. At the same time, the neural mechanisms of movement performance and the role of basal ganglia in motor control remains unclear. The aim of this study was to compare neuronal responses in subthalamic nucleus (STN) during ET and IG movements in PD. We found and analyzed 26 sensitive neurons in 12 PD patients who underwent surgery for implantation of electrodes for deep brain stimulation. We also analyzed the local field potentials (LFP) of the STN of 6 patients in the postoperative period. Patients were asked to perform voluntary movements (clenching and unclenching the fist) evoked by verbal command (ET) or self-initiated (IG). We showed heterogeneity of neuronal responses and did not find sensitive neurons associated with only one type of movement. Most cells were characterized by leading responses, indicating that the STN has an important role in movement initiation. At the same time, we found attenuation of motor responses during IG movement versus stable responses during ET movemements. LFP analysis also showed attenuation of beta desynchronization during multiple IG movements. We propose that stable neuronal response to ET movements is associated with reboot of the motor program for each movement, while attenuation of responses to IG movement is associated with single motor program launching for multiple movements.

neuroscience↗

Mechanism and functional role of the interaction between CP190 and the architectural protein Pita in Drosophila melanogaster

The architectural protein Pita is critical for Drosophila embryogenesis and predominantly binds to gene promoters and insulators. In particular, Pita is involved in the organization of boundaries between regulatory domains that controlled the expression of three hox genes in the Bithorax complex (BX-C). The best-characterized partner for Pita is the BTB/POZ-domain containing protein CP190. Using in vitro pull-down analysis, we precisely mapped two unstructured regions of Pita that interact with the BTB domain of CP190. Then we constructed transgenic lines expressing the Pita protein of the wild-type and mutant variants lacking CP190-interacting regions. The expression of the mutant protein completely complemented the null pita mutation. ChIP-seq experiments with wild-type and mutant embryos showed that the deletion of the CP190-interacting regions did not significantly affect the binding of the mutant Pita protein to most chromatin sites. However, the mutant Pita protein does not support the ability of multimerized Pita sites to prevent cross-talk between the iab-6 and iab-7 regulatory domains that activate the expression of Abdominal-B (Abd-B), one of the genes in the BX-C. The recruitment of a chimeric protein consisting of the DNA-binding domain of GAL4 and CP190-interacting region of the Pita to the GAL4 binding sites on the polytene chromosomes of larvae induces the formation of a new interband, which is a consequence of the formation of open chromatin in this region. These results suggested that the interaction with CP190 is required for the primary Pita activities, but other architectural proteins may also recruit CP190 in flies expressing only the mutant Pita protein. Author SummaryPita is required for Drosophila development and binds specifically to a long motif in active promoters and insulators. Pita belongs to the Drosophila family of zinc-finger architectural proteins, which also includes Su(Hw) and the conserved among higher eukaryotes CTCF. The architectural proteins maintain the active state of regulatory elements and the long-distance interactions between them. The CP190 protein is recruited to chromatin through interaction with the architectural proteins. Here we mapped two regions in Pita that are required for interaction with the CP190 protein. We have demonstrated that CP190-interacting region of the Pita can maintain nucleosome-free open chromatin and is critical for Pita-mediated enhancer blocking activity. At the same time, interaction with CP190 is not required for the in vivo function of the mutant Pita protein, which binds to the same regions of the genome as the wild-type protein. Unexpectedly, we found that CP190 was still associated with the most of genome regions bound by the mutant Pita protein, which suggested that other architectural proteins were continuing to recruit CP190 to these regions. These results support a model in which the regulatory elements are composed of combinations of binding sites that interact with several architectural proteins with similar functions.

molecular biology↗

A Non-stop identity complex (NIC) supervises enterocyte identity and protects from pre-mature aging

A hallmark of aging is the inability of differentiated cells to maintain their identity. In the aged Drosophila midgut differentiated enterocytes (ECs) lose their identity, and the integrity of the midgut tissue and its homeostasis are impaired. To discover regulators of EC identity relevant to aging we performed an RNAi screen targeting 453 ubiquitin-related genes in fully differentiated ECs. Seventeen genes were identified, including the de-ubiquitinase Non-stop (Not/dUSP22; CG4166). Acute loss of Non-stop in young ECs phenotypically resembled aged ECs. Lineage tracing experiments established that Non-stop-deficient young ECs as well as wild-type aged ECs are no longer differentiated. Aging or acute loss of Non-stop also resulted in progenitor cell hyperproliferation and mis-differentiation, loss of gut integrity, and reduced organismal survival. Proteomic analysis unveiled that Non-stop maintains identity as part of a Non-stop identity complex (NIC) that contains E(y)2, Sgf11, Cp190, (Mod) mdg4, and Nup98. Transcriptionally, Non-stop ensured chromatin accessibility at EC genes, maintained an EC-specific gene expression signature, and silenced non-EC-relevant transcriptional programs. Within the NIC, Non-stop was required for stabilizing of NIC subunits. Upon aging, the levels of Non-stop and NIC subunits declined, and the large-scale organization of the nucleus was distorted. Maintaining youthful levels of Non-stop in wildtype aged ECs safeguarded the protein level of NIC subunits, restored the large-scale organization of the differentiated nucleus, and suppressed aging phenotypes and tissue integrity. Thus, the isopeptidase Non-stop, and NIC, supervise EC identity and protects from premature aging.

cell biology↗