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Chandra, A.

Publications and source records attributed to Chandra, A..

At least 37 records · Page 2Linked to original sources

BRDKRM: An Explainable Framework for Disease Modifying Drug Identification

Drug classification into disease-modifying (DM) and symptomatic (SYM) categories is crucial for clinical decision-making and therapeutic strategy development. To address the limitations of current methods, which often lack transparency and interpretability, we propose the Boundary Restricted Dynamic Key Route Mapping (BRDKRM) framework. This novel approach leverages the contextual overlap between disease and drug nodes in a heterogeneous graph, aggregating genes from the top K shortest paths to delineate disease neighborhood boundaries. Inspired by the classic Hansel and Gretel folklore, BRDKRM metaphorically marks boundary nodes along metapaths from disease to drug, akin to Hansel s breadcrumbs, which are then used to classify the therapeutic effect of candidate drugs. Our method achieved 86.78% accuracy in categorizing drug-disease treatments and identified 530 genes involved in both disease modification and symptomatic relief. The efficacy of BRDKRM is demonstrated through case studies on multiple sclerosis, offering an explainable approach to drug classification that bypasses extensive clinical trials. By providing biologically sound interpretations of drug classifications, our framework enhances understanding of therapeutic interventions, paving the way for more precise and efficient healthcare solutions while offering a novel approach to mapping disease-drug interactions.

bioinformatics↗

Aberrant TNF signaling in pancreatic lymph nodes of patients with Type 1 Diabetes

The therapeutic landscape for Type 1 Diabetes (T1D) is rapidly changing as ongoing clinical trials aim to delay beta-cell loss by inhibiting proinflammatory cytokines. However, the precise timing and cellular contexts of cytokine dysregulation remains unknown. We generated the largest existing measurement of gene expression and chromatin accessibility in [~]1 million immune cells from the pancreatic lymph nodes and spleens of 34 T1D and non-diabetic organ donors. Our study revealed heightened gene activity of the tumor necrosis factor (TNF) pathway and subsequent chromatin remodeling in central memory CD4+ T cells residing in the pancreatic lymph nodes of T1D and non-diabetic islet-autoantibody positive donors. These findings, validated in mice, offer a mechanism underlying the efficacy of TNF inhibitors, currently undergoing clinical trials to delay T1D onset.

immunology↗

Avian influenza virus neuraminidase stalk length and haemagglutinin glycosylation patterns reveal molecularly directed reassortment promoting the emergence of highly pathogenic clade 2.3.4.4b A (H5N1) viruses

The recently emerged panzootic clade 2.3.4.4b H5N1 influenza viruses show unprecedented extensive spread in wild birds and have been transmitted to several mammals, including humans. The virologic factors that have driven the success of the 2.3.4.4b H5N1 viruses, which has not been achieved by previous H5N1 clades, is unclear. We show that the 2.3.4.4b H5 haemagglutinin (HA) paired exclusively with full length (long stalk) N1 neuraminidase (NA) in birds and mammals, unlike previous clades of H5 viruses, which preferentially paired with N1 proteins with stalk deletions (short stalk). We found that the emergence of a 2.3.4.4b H5 HA with seven glycosylation sites was critical in driving its pairing with long stalk N1. The earlier H5 clades that paired with short stalk N1s showed a pattern of eight or more glycosylation sites. A prior shift in a glycosylation site from position 103 to 171 in the receptor binding domain of H5 HA and the subsequent S173A mutation that removed it triggered the emergence of 2.3.4.4b clade H5N1 viruses. Thus, the evolution of novel variations in the H5 HA and their preference for long stalk N1 pairing led to increased fitness and pathogenicity. These observations led us to establish and validate the hypothesis that the pairing of avian virus HA and NA subtypes is not stochastic but is rather molecularly programmed by HA glycosylation and NA stalk length, modulating fitness and emergence of novel avian influenza viruses. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=182 SRC="FIGDIR/small/595329v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@1659b26org.highwire.dtl.DTLVardef@1ace4b6org.highwire.dtl.DTLVardef@1db7c0corg.highwire.dtl.DTLVardef@ad3654_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

TET2 regulates early and late transitions in exhausted CD8+ T-cell differentiation and limits CAR T-cell function

CD8+ T-cell exhaustion hampers disease control in cancer and chronic infections and limits efficacy of T-cell-based therapies, such as CAR T-cells. Epigenetic reprogramming of CAR T-cells by targeting TET2, a methylcytosine dioxygenase that mediates active DNA demethylation, has shown therapeutic potential; however, the role of TET2 in exhausted T-cell (TEX) development is unclear. In CAR T-cell exhaustion models and chronic LCMV infection, TET2 drove the conversion from stem cell-like, self-renewing TEX progenitors towards terminally differentiated and effector (TEFF)-like TEX. In mouse T-cells, TET2-deficient terminally differentiated TEX retained aspects of TEX progenitor biology, alongside decreased expression of the transcription factor TOX, suggesting that TET2 potentiates terminal exhaustion. TET2 also enforced a TEFF-like terminally differentiated CD8+ T-cell state in the early bifurcation between TEFF and TEX, indicating a broad role for TET2 in mediating the acquisition of an effector biology program that could be exploited therapeutically. Finally, we developed a clinically actionable strategy for TET2- targeted CAR T-cells, using CRISPR/Cas9 editing and site-specific adeno-associated virus transduction to simultaneously knock-in a CAR at the TRAC locus and a functional safety switch within TET2. Disruption of TET2 with this safety switch in CAR T-cells restrained terminal TEX differentiation in vitro and enhanced anti-tumor responses in vivo. Thus, TET2 regulates pivotal fate transitions in TEX differentiation and can be targeted with a safety mechanism in CAR T-cells for improved tumor control and risk mitigation. One Sentence SummaryModulation of exhausted CD8+ T-cell differentiation by targeting TET2 improves therapeutic potential of CAR T-cells in cancer.

immunology↗

Transcriptomic analysis of the human habenula in schizophrenia

Pathophysiology of many neuropsychiatric disorders, including schizophrenia (SCZD), is linked to habenula (Hb) function. While pharmacotherapies and deep brain stimulation targeting the Hb are emerging as promising therapeutic treatments, little is known about the cell type-specific transcriptomic organization of the human Hb or how it is altered in SCZD. Here we define the molecular neuroanatomy of the human Hb and identify transcriptomic changes in individuals with SCZD compared to neurotypical controls. Utilizing Hb-enriched postmortem human brain tissue, we performed single nucleus RNA-sequencing (snRNA-seq; n=7 neurotypical donors) and identified 17 molecularly defined Hb cell types across 16,437 nuclei, including 3 medial and 7 lateral Hb populations, several of which were conserved between rodents and humans. Single molecule fluorescent in situ hybridization (smFISH; n=3 neurotypical donors) validated snRNA-seq Hb cell types and mapped their spatial locations. Bulk RNA-sequencing and cell type deconvolution in Hb-enriched tissue from 35 individuals with SCZD and 33 neurotypical controls yielded 45 SCZD-associated differentially expressed genes (DEGs, FDR < 0.05), with 32 (71%) unique to Hb-enriched tissue. eQTL analysis identified 717 independent SNP-gene pairs (FDR < 0.05), where either the SNP is a SCZD risk variant (16 pairs) or the gene is a SCZD DEG (7 pairs). eQTL and SCZD risk colocalization analysis identified 16 colocalized genes. These results identify topographically organized cell types with distinct molecular signatures in the human Hb and demonstrate unique genetic changes associated with SCZD, thereby providing novel molecular insights into the role of Hb in neuropsychiatric disorders. One Sentence SummaryTranscriptomic analysis of the human habenula and identification of molecular changes associated with schizophrenia risk and illness state.

neuroscience↗

Complex carbohydrate utilization by gut bacteria modulates host food preference

The gut microbiota interacts directly with dietary nutrients and has the ability to modify host feeding behavior, but the underlying mechanisms remain poorly understood. Select gut bacteria digest complex carbohydrates that are non-digestible by the host and liberate metabolites that serve as additional energy sources and pleiotropic signaling molecules. Here we use a gnotobiotic mouse model to examine how differential fructose polysaccharide metabolism by commensal gut bacteria influences host preference for diets containing these carbohydrates. Bacteroides thetaiotaomicron and Bacteroides ovatus selectively ferment fructans with different glycosidic linkages: B. thetaiotaomicron ferments levan with {beta}2-6 linkages, whereas B. ovatus ferments inulin with {beta}2-1 linkages. Since inulin and levan are both fructose polymers, inulin and levan diet have similar perceptual salience to mice. We find that mice colonized with B. thetaiotaomicron prefer the non-fermentable inulin diet, while mice colonized with B. ovatus prefer the non-fermentable levan diet. Knockout of bacterial fructan utilization genes abrogates this preference, whereas swapping the fermentation ability of B. thetaiotaomicron to inulin confers host preference for the levan diet. Bacterial fructan fermentation and host behavioral preference for the non-fermentable fructan are associated with increased neuronal activation in the arcuate nucleus of the hypothalamus, a key brain region for appetite regulation. These results reveal that selective nutrient metabolism by gut bacteria contributes to host associative learning of dietary preference, and further informs fundamental understanding of the biological determinants of food choice.

microbiology↗

Osteochondroprogenitor cells and neutrophils expressing p21 and senescence markers modulate fracture repair

Cells expressing features of senescence, including upregulation of p21 and p16, appear transiently following tissue injury, yet the properties of these cells or how they contrast with age-induced senescent cells remains unclear. Here, we used skeletal injury as a model and identified the rapid appearance following fracture of p21+ cells expressing senescence markers, mainly as osteochondroprogenitors (OCHs) and neutrophils. Targeted genetic clearance of p21+ cells suppressed senescence-associated signatures within the fracture callus and accelerated fracture healing. By contrast, p21+ cell clearance did not alter bone loss due to aging; conversely, p16+ cell clearance, known to alleviate skeletal aging, did not affect fracture healing. Following fracture, p21+ neutrophils were enriched in signaling pathways known to induce paracrine stromal senescence, while p21+ OCHs were highly enriched in senescence-associated secretory phenotype factors known to impair bone formation. Further analysis revealed an injury-specific stem cell-like OCH subset that was p21+ and highly inflammatory, with a similar inflammatory mesenchymal population (fibro-adipogenic progenitors) evident following muscle injury. Thus, intercommunicating senescent-like neutrophils and mesenchymal progenitor cells are key regulators of tissue repair in bone and potentially across tissues. Moreover, our findings establish contextual roles of p21+ vs p16+ senescent/senescent-like cells that may be leveraged for therapeutic opportunities.

physiology↗

Prognostic relevance of correlated co-expression of coding and noncoding RNAs in cervical cancers

Human papillomavirus (HPV) drives cervical cancer (CaCx) pathogenesis and viral oncoproteins jeopardize global gene expression in such cancers. We aimed to identify differentially expressed coding (DEcGs) and long noncoding (sense intronic and Natural Antisense Transcripts) RNA genes (DElncGs) in HPV16-positive CaCx patients (N=44) compared to HPV-negative normal individuals (N=34). Thereby, employing strand-specific RNA-seq, we determined the relationships between DEcGs and DElncGs and their clinical implications. Gene set enrichment and protein-protein interaction analyses of DEcGs revealed enrichment of processes crucial for abortive virus life cycle and cancer progression. The DEcGs formed 16 gene clusters, portraying cancer-related functions. We recorded significantly correlated co-expression of 79 DElncGs with DEcGs at proximal genomic loci, and 24 such pairs portrayed significantly altered correlation coefficients among patients, compared to normal individuals. Of these, 6 DEcGs belonged to 5 gene clusters, one of which was survival-associated. Out of the 24 correlated DEcG: DElncG pairs, 3 pairs were identified, where expression of both members was significantly associated with patient overall survival. Besides being prognostically relevant, disruption of the significant correlative relationships of such gene pairs in CaCx bears immense potential for patient-targeted therapy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/573593v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@19091c8org.highwire.dtl.DTLVardef@52fbeaorg.highwire.dtl.DTLVardef@18ecf3org.highwire.dtl.DTLVardef@6c5e30_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract:C_FLOATNO A schematic representation of the analyses undertaken to draw insights on the biological relevance of joint analysis of co-expressed and significantly correlated DElncGs and DEcGs considering the ncNATs and sense intronic DElncGs, in HPV16-positive CaCx patients compared with HPV-negative normal individuals. C_FIG

cancer biology↗

Deep Learning for Protein Peptide bindingPrediction: Incorporating Sequence, Structural andLanguage Model Features

Protein-peptide interactions play a crucial role in various cellular processes and are implicated in abnormal cellular behaviors leading to diseases such as cancer. Therefore, understanding these interactions is vital for both functional genomics and drug discovery efforts. Despite a significant increase in the availability of protein-peptide complexes, experimental methods for studying these interactions remain laborious, time-consuming, and expensive. Computational methods offer a complementary approach but often fall short in terms of prediction accuracy. To address these challenges, we introduce PepCNN, a deep learning-based prediction model that incorporates structural and sequence-based information from primary protein sequences. By utilizing a combination of half-sphere exposure, position specific scoring matrices, and pre-trained transformer language model, PepCNN outperforms state-of-the-art methods in terms of specificity, precision, and AUC. The PepCNN software and datasets are publicly available at https://github.com/abelavit/PepCNN.git.

bioinformatics↗

Transcriptional regulation of Dyskerin via canonical WNT signaling modulates sphingolipid biosynthesis and drives colorectal cancer.

Targeting EGFR has been effective in RAS/RAF wild-type colorectal cancer (CRC) patients. However, residual tumor relapses, necessitating the importance of biomarker-guided novel therapeutics. We show elevated DKC1 in [~]88% of CRC patients with poor recurrence-free survival. Clinically, DKC1-positive patients exhibit similarity with CMS2 class, the canonical subtype with active WNT signaling. We show functional significance of DKC1 in cell proliferation, stemness, DNA repair, and survival. Further, mice bearing DKC1 knockdown xenografts show [~]81% reduction in tumor burden. Mechanistically, WNT/{beta}-catenin signaling orchestrates DKC1 expression, then, DKC1/SOX2 complex regulates SGPP2, modulating sphingolipids metabolism. Downregulation of DKC1 in CRC lead to reduced SGPP2 levels leading to dysregulation of sphingolipid biosynthesis. Of note, DKC1-high CRC patients show accumulation of ceramides, namely C23 and C24, signifying their utility in diagnosis. Collectively, we delineate the mechanistic circuitry involved in DKC1-mediated CRC progression, propose ceramides as biomarker, and underscore WNT-based therapeutics for DKC1-positive patients.

cancer biology↗

A multi-enhancer hub at the Ets1 locus controls T cell differentiation and allergic inflammation through 3D genome topology

Multi-enhancer hubs are spatial clusters of enhancers which have been recently characterized across numerous developmental programs. Yet, the functional relevance of these three-dimensional (3D) structures is poorly understood. Here we show that the multiplicity of enhancers interacting with the transcription factor Ets1 is essential to control the precise expression level of this gene in response to cellular cues, and the failure to do so can lead to allergic diseases. Focusing on T cells as a model, we identified a highly connected multi-enhancer hub at the Ets1 locus, comprising a noncoding regulatory element that is a hotspot for sequence variation associated with allergic diseases. We deleted this hotspot and found that the multi-enhancer connectivity is dispensable for T cell development but required for CD4+ T helper (Th1) differentiation in response to changes in the cytokine milieu. Mice lacking this hotspot are thus protected from Th1-mediated colitis but demonstrate an overt allergic response to house dust mites, a T cell-mediated response which is dampened by Th1 cells. Mechanistically, the multi-enhancer hub controls the expression level of Ets1 that is dispensable for the active enhancer landscape but required for the Th1-specific genome topology through recruitment of CTCF. Together, we establish a paradigm for the functional and mechanistic relevance of multi-enhancer hubs controlling cellular competence to respond specifically to an inductive cue.

genomics↗

Probing single cell fermentation flux and intercellular exchange networks via pH-microenvironment sensing and inverse modeling

The homeostatic control of their environment is an essential task of living cells. It has been hypothesized that when microenvironmental pH inhomogeneities are induced by high cellular metabolic activity, diffusing protons act as signaling molecules, driving the establishment of cross-feeding networks sustained by the cell-to-cell shuttling of overflow products such as lactate. Despite their fundamental role, the extent and dynamics of such networks is largely unknown due to the lack of methods in single cell flux analysis. In this study we provide direct experimental characterization of such exchange networks. We devise a method to quantify single cell fermentation fluxes over time by integrating high-resolution pH microenvironment sensing via ratiometric nanofibers with constraint-based inverse modeling. We apply our method to cell cultures with mixed populations of cancer cells and fibroblasts. We find that the proton trafficking underlying bulk acidification is strongly heterogeneous, with maximal single cell fluxes exceeding typical values by up to 3 orders of magnitude. In addition, a crossover in time from a networked phase sustained by densely connected "hubs" (corresponding to cells with high activity) to a sparse phase dominated by isolated dipolar motifs (i.e. by pair-wise cell-to-cell exchanges) is uncovered, which parallels the time course of bulk acidification. Our method promises to shed light on issues ranging from the homeostatic function of proton exchange to the metabolic coupling of cells with different energetic demands, and paves the way for real-time non-invasive single cell metabolic flux analysis.

biophysics↗

Peptide derived nanobody inhibits entry of SARS-CoV-2 variants

Emergence of the new escape mutants of the SARS-CoV-2 virus has escalated its penetration among the human population and has reinstated its status as a global pandemic. Therefore, developing effective antiviral therapy against emerging SARS variants and other viruses in a short period of time becomes essential. Blocking the SARS-CoV-2 entry into human host cells by disrupting the spike glycoprotein-ACE2 interaction has been already exploited for vaccine development and monoclonal antibody therapy. Unlike the previous reports, our study used a 9 amino acid peptide from the receptor-binding motif (RBM) of Spike (S) protein as an epitope. We report the identification of an efficacious nanobody N1.2 that blocks the entry of pseudovirus containing SARS-CoV-2 spike as the surface glycoprotein. Moreover, we observe a more potent neutralizing effect against both the hCoV19 (Wuhan/WIV04/2019) and the Omicron (BA.1) pseudotyped spike virus with a bivalent version of the nanobody. In summary, our study presents a faster and efficient methodology to use peptide sequences from a protein-receptor interaction interface as epitopes for screening nanobodies against potential pathogenic targets. This approach can also be widely extended to target other viruses and pathogens in the future.

cell biology↗

High-throughput Oligopaint screen identifies druggable regulators of genome folding

Although the molecular rules governing genome organization are being quickly elucidated, relatively few proteins regulating this process have been identified. To address this gap, we developed a fully automated imaging pipeline, called HiDRO (high-throughput DNA or RNA labeling with optimized Oligopaints), that permits quantitative measurement of chromatin interactions across a large number of samples. Using HiDRO, we screened the human druggable genome and identified >300 factors that regulate chromatin folding during interphase, including 43 validated hits that either increase or decrease interactions between topological associating domains (TADs). We discovered that genetic or chemical inhibition of the ubiquitous kinase GSK3A enhances long-range interactions by dysregulating cohesin-mediated chromatin looping. Collectively, these results highlight a noncanonical role for GSK3A signaling in nuclear architecture and underscore the broader utility of HiDRO-based screening to identify novel mechanisms that drive the spatial organization of the genome.

genetics↗

Roles of cellular senescence in driving bone marrow adiposity in radiation-and aging-associated bone loss

Osteoporosis is associated with an increase in marrow adipocytes, collectively termed bone marrow adipose tissue (BMAT). An increase in BMAT is linked with decline of mesenchymal progenitors that give rise to osteoblasts which are responsible for bone accrual. Oxidative stress-induced reactive oxygen species, DNA damage, apoptosis and cellular senescence have been associated with reduced osteoprogenitors in a reciprocal fashion to BMAT; however, a direct (causal) link between cellular senescence and BMAT is still elusive. Accumulation of senescent cells occur in naturally aged and in focally radiated bone tissue, but despite amelioration of age- and radiation-associated bone loss after senescent cell clearance, molecular events that precede BMAT accrual are largely unknown. Using a mouse model here we show by RNA-Sequencing data that BMAT-related genes were the most upregulated gene subset in radiated bones. Using focal radiation as a model to understand age-associated changes in bone, we performed a longitudinal assessment of cellular senescence and BMAT. Using qRT-PCR, RNA in situ hybridization and histological assessment of telomere dysfunction as a marker of senescence, we observed increased p21 transcripts in bone lining cells, osteocytes and bone marrow cells, and elevated dysfunctional telomeres in osteocytes starting from day 1 post-radiation, without the presence of BMAT. BMAT was significantly elevated in radiated bones at day 7, confirming the qRT-PCR data in which most BMAT-related genes were elevated by day 7, and the trend continued until day 42 post-radiation. Similarly, elevation in BMAT-related genes was observed in aged bones. The senolytic cocktail of Dasatinib (D) plus Quercetin (Q) - D+Q, which clears senescent cells, reduced BMAT in aged and radiated bones. MicroRNAs (miRs) linked with senescence marker p21 were downregulated in radiated- and aged-bones, while miR-27a, a miR that is associated with increased BMAT, was elevated both in radiated- and aged-bones. D+Q downregulated miR-27a in radiated bones at 42 days post-radiation. Overall, our study provides evidence that BMAT occurrence in oxidatively stressed bone environments, such as radiation and aging, is induced following a common pathway and is dependent on the presence of senescent cells.

molecular biology↗

Identification of Cancer-Associated Fibroblasts in Glioblastoma and Defining Their Pro-tumoral Effects

Despite their identification in some cancers, pro-tumoral cancer-associated fibroblasts (CAFs) were presumed absent in glioblastoma given the lack of brain fibroblasts. Serial trypsinization of primary glioblastoma cultures yielded cells with CAF morphology, CAF transcriptomic profile, and mesenchymal lineage in single-cell RNA-seq. Glioblastoma CAFs were attracted to glioblastoma stem cells (GSCs) and CAFs enriched GSCs. We created a resource of inferred crosstalk by mapping expression of receptors to their cognate ligands, identifying PDGF-{beta} and TGF-{beta} as mediators of GSC effects on CAFs, and osteopontin and hepatocyte growth factor as mediators of CAF-induced GSC enrichment. Glioblastoma CAFs also induced M2 macrophage polarization by producing the EDA fibronectin variant. Glioblastoma CAFs were enriched in the subventricular zone which houses neural stem cells that produce GSCs. Including CAFs in GSC-derived xenografts induced in vivo growth. These findings are among the first to identify glioblastoma CAFs and their GSC interactions, making them an intriguing target.

cancer biology↗

Niclosamide inhibits SARS-CoV2 entry by blocking internalization through pH-dependent CLIC/GEEC endocytic pathway

Many viruses utilize the host endo-lysosomal network to infect cells. Tracing the endocytic itinerary of SARS-CoV2 can provide insights into viral trafficking and aid in designing new therapeutic targets. Here, we demonstrate that the receptor binding domain (RBD) of SARS-CoV2 is internalized via the clathrin and dynamin-independent, pH-dependent CLIC/GEEC (CG) endocytic pathway. Endosomal acidification inhibitors like BafilomycinA1 and NH4Cl, which inhibit the CG pathway, strongly block the uptake of RBD. Using transduction assays with SARS-CoV2 Spike-pseudovirus, we confirmed that these acidification inhibitors also impede viral infection. By contrast, Chloroquine neither affects RBD uptake nor extensively alters the endosomal pH, yet attenuates Spike-pseudovirus entry, indicating a pH-independent mechanism of intervention. We screened a subset of FDA-approved acidification inhibitors and found Niclosamide to be a potential SARS-CoV2 entry inhibitor. Niclosamide, thus, could provide broader applicability in subverting infection of similar category viruses entering host cells via this pH-dependent endocytic pathway.

cell biology↗

Role of c-Met/β1 integrin complex in the metastatic cascade

Metastases cause 90% of human cancer deaths. The metastatic cascade involves local invasion, intravasation, extravasation, metastatic site colonization, and proliferation. While individual mediators of these processes have been investigated, interactions between these mediators remain less well defined. We previously identified a structural complex between receptor tyrosine kinase c-Met and {beta}1 integrin in metastases. Using novel cell culture and in vivo assays, we found that c-Met/{beta}1 complex induction promotes breast cancer intravasation and adhesion to the vessel wall, but does not increase extravasation. These effects may be driven by the ability of the c-Met/{beta}1 complex to increase mesenchymal and stem cell characteristics. Multiplex transcriptomic analysis revealed upregulated Wnt and hedgehog pathways after c-Met/{beta}1 complex induction. A {beta}1 integrin point mutation that prevented binding to c-Met reduced intravasation. OS2966, a therapeutic antibody disrupting c-Met/{beta}1 binding, decreased invasion and mesenchymal gene expression and morphology of breast cancer cells. Bone-seeking breast cancer cells exhibited higher c-Met/{beta}1 complex levels than parental controls and preferentially adhere to tissue-specific matrix. Patient bone metastases demonstrated higher c-Met/{beta}1 levels than brain metastases. Thus, the c-Met/{beta}1 complex drives breast cancer cell intravasation and preferential affinity for bone tissue-specific matrix. Pharmacological targeting of the complex may prevent metastases, particularly osseous metastases.

cancer biology↗