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1.
Immunity ; 56(12): 2755-2772.e8, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38039967

ABSTRACT

In triple-negative breast cancer (TNBC), stromal restriction of CD8+ T cells associates with poor clinical outcomes and lack of responsiveness to immune-checkpoint blockade (ICB). To identify mediators of T cell stromal restriction, we profiled murine breast tumors lacking the transcription factor Stat3, which is commonly hyperactive in breast cancers and promotes an immunosuppressive tumor microenvironment. Expression of the cytokine Chi3l1 was decreased in Stat3-/- tumors. CHI3L1 expression was elevated in human TNBCs and other solid tumors exhibiting T cell stromal restriction. Chi3l1 ablation in the polyoma virus middle T (PyMT) breast cancer model generated an anti-tumor immune response and delayed mammary tumor onset. These effects were associated with increased T cell tumor infiltration and improved response to ICB. Mechanistically, Chi3l1 promoted neutrophil recruitment and neutrophil extracellular trap formation, which blocked T cell infiltration. Our findings provide insight into the mechanism underlying stromal restriction of CD8+ T cells and suggest that targeting Chi3l1 may promote anti-tumor immunity in various tumor types.


Subject(s)
Extracellular Traps , Triple Negative Breast Neoplasms , Animals , Humans , Mice , CD8-Positive T-Lymphocytes , Cell Line, Tumor , Cytokines , Extracellular Traps/metabolism , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Tumor Microenvironment
2.
Nature ; 614(7948): 555-563, 2023 02.
Article in English | MEDLINE | ID: mdl-36725935

ABSTRACT

Single-cell technologies have enabled the characterization of the tumour microenvironment at unprecedented depth and have revealed vast cellular diversity among tumour cells and their niche. Anti-tumour immunity relies on cell-cell relationships within the tumour microenvironment1,2, yet many single-cell studies lack spatial context and rely on dissociated tissues3. Here we applied imaging mass cytometry to characterize the immunological landscape of 139 high-grade glioma and 46 brain metastasis tumours from patients. Single-cell analysis of more than 1.1 million cells across 389 high-dimensional histopathology images enabled the spatial resolution of immune lineages and activation states, revealing differences in immune landscapes between primary tumours and brain metastases from diverse solid cancers. These analyses revealed cellular neighbourhoods associated with survival in patients with glioblastoma, which we leveraged to identify a unique population of myeloperoxidase (MPO)-positive macrophages associated with long-term survival. Our findings provide insight into the biology of primary and metastatic brain tumours, reinforcing the value of integrating spatial resolution to single-cell datasets to dissect the microenvironmental contexture of cancer.


Subject(s)
Brain Neoplasms , Glioma , Single-Cell Analysis , Tumor Microenvironment , Humans , Brain/immunology , Brain/pathology , Brain Neoplasms/immunology , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Glioblastoma/immunology , Glioblastoma/pathology , Glioma/immunology , Glioma/pathology , Macrophages/enzymology , Tumor Microenvironment/immunology , Neoplasm Metastasis , Datasets as Topic
3.
Nature ; 605(7911): 747-753, 2022 05.
Article in English | MEDLINE | ID: mdl-35585241

ABSTRACT

Cancer metastasis requires the transient activation of cellular programs enabling dissemination and seeding in distant organs1. Genetic, transcriptional and translational heterogeneity contributes to this dynamic process2,3. Metabolic heterogeneity has also been observed4, yet its role in cancer progression is less explored. Here we find that the loss of phosphoglycerate dehydrogenase (PHGDH) potentiates metastatic dissemination. Specifically, we find that heterogeneous or low PHGDH expression in primary tumours of patients with breast cancer is associated with decreased metastasis-free survival time. In mice, circulating tumour cells and early metastatic lesions are enriched with Phgdhlow cancer cells, and silencing Phgdh in primary tumours increases metastasis formation. Mechanistically, Phgdh interacts with the glycolytic enzyme phosphofructokinase, and the loss of this interaction activates the hexosamine-sialic acid pathway, which provides precursors for protein glycosylation. As a consequence, aberrant protein glycosylation occurs, including increased sialylation of integrin αvß3, which potentiates cell migration and invasion. Inhibition of sialylation counteracts the metastatic ability of Phgdhlow cancer cells. In conclusion, although the catalytic activity of PHGDH supports cancer cell proliferation, low PHGDH protein expression non-catalytically potentiates cancer dissemination and metastasis formation. Thus, the presence of PHDGH heterogeneity in primary tumours could be considered a sign of tumour aggressiveness.


Subject(s)
Breast Neoplasms , Neoplasm Metastasis , Phosphoglycerate Dehydrogenase , Animals , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Movement , Cell Proliferation , Disease Progression , Female , Gene Silencing , Humans , Mice , Phosphoglycerate Dehydrogenase/genetics , Serine/metabolism
4.
Proc Natl Acad Sci U S A ; 120(33): e2303010120, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37549258

ABSTRACT

The regulation of gene expression through histone posttranslational modifications plays a crucial role in breast cancer progression. However, the molecular mechanisms underlying the contribution of histone modification to tumor initiation remain unclear. To gain a deeper understanding of the role of the histone modifier Enhancer of Zeste homology 2 (Ezh2) in the early stages of mammary tumor progression, we employed an inducible mammary organoid system bearing conditional Ezh2 alleles that faithfully recapitulates key events of luminal B breast cancer initiation. We showed that the loss of Ezh2 severely impairs oncogene-induced organoid growth, with Ezh2-deficient organoids maintaining a polarized epithelial phenotype. Transcriptomic profiling showed that Ezh2-deficient mammary epithelial cells up-regulated the expression of negative regulators of Wnt signaling and down-regulated genes involved in mTORC1 (mechanistic target of rapamycin complex 1) signaling. We identified Sfrp1, a Wnt signaling suppressor, as an Ezh2 target gene that is derepressed and expressed in Ezh2-deficient epithelium. Furthermore, an analysis of breast cancer data revealed that Sfrp1 expression was associated with favorable clinical outcomes in luminal B breast cancer patients. Finally, we confirmed that targeting Ezh2 impairs mTORC1 activity through an indirect mechanism that up-regulates the expression of the tumor suppressor Pten. These findings indicate that Ezh2 integrates the mTORC1 and Wnt signaling pathways during early mammary tumor progression, arguing that inhibiting Ezh2 or therapeutically targeting Ezh2-dependent programs could be beneficial for the treatment of early-stage luminal B breast cancer.


Subject(s)
Histones , Polycomb Repressive Complex 2 , Cell Line, Tumor , Cell Transformation, Neoplastic/genetics , Enhancer of Zeste Homolog 2 Protein/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Histones/metabolism , Polycomb Repressive Complex 2/genetics , Polycomb Repressive Complex 2/metabolism , Wnt Signaling Pathway/genetics
6.
Proc Natl Acad Sci U S A ; 117(33): 20139-20148, 2020 08 18.
Article in English | MEDLINE | ID: mdl-32727899

ABSTRACT

Lung cancer causes more deaths annually than any other malignancy. A subset of non-small cell lung cancer (NSCLC) is driven by amplification and overexpression or activating mutation of the receptor tyrosine kinase (RTK) ERBB2 In some contexts, notably breast cancer, alternative splicing of ERBB2 causes skipping of exon 16, leading to the expression of an oncogenic ERBB2 isoform (ERBB2ΔEx16) that forms constitutively active homodimers. However, the broader implications of ERBB2 alternative splicing in human cancers have not been explored. Here, we have used genomic and transcriptomic analysis to identify elevated ERBB2ΔEx16 expression in a subset of NSCLC cases, as well as splicing site mutations facilitating exon 16 skipping and deletions of exon 16 in a subset of these lung tumors and in a number of other carcinomas. Supporting the potential of ERBB2ΔEx16 as a lung cancer driver, its expression transformed immortalized lung epithelial cells while a transgenic model featuring inducible ERBB2ΔEx16 specifically in the lung epithelium rapidly developed lung adenocarcinomas following transgene induction. Collectively, these observations indicate that ERBB2ΔEx16 is a lung cancer oncogene with potential clinical importance for a proportion of patients.


Subject(s)
Carcinoma/genetics , Genetic Predisposition to Disease , Lung Neoplasms/genetics , Protein Isoforms/genetics , Receptor, ErbB-2/metabolism , Animals , Cell Line, Tumor , Female , Humans , Male , Mice , Rats , Receptor, ErbB-2/genetics , Tumor Microenvironment
7.
Biotechnol Lett ; 44(11): 1263-1275, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36261682

ABSTRACT

OBJECTIVES: Bone marrow-derived mesenchymal stem cells (BMSCs) show promise in treating inflammatory bowel disease. We tested if BMSCs improve Trinitro-benzene-sulfonic acid (TNBS)-induced colitis by inducing Treg differentiation by modulating programmed cell death 1 ligand 1(PD-L1). RESULTS: BMSCs were isolated and transfected with PD-L1 siRNA. Sprague-Dawley rats were randomly divided into 4 groups: normal, model, BMSC control, and PD-L1 siRNA BMSC. Colitis was induced by TNBS, except in the normal group. On d4, the BMSC control and PD-L1 siRNA BMSC groups were intravenously injected with BMSCs at a dose of 5 × 106 cells in phosphate-buffered saline (PBS; volume matched). BMSCs were later verified to have reached the colon tissue. BMSC control showed significantly better clinical symptoms and reduced histopathological colitis severity; PD-L1 siRNA BMSC group showed no difference. PD-L1 siRNA reduced: spleen and mesenteric lymph node Tregs, PD-L1, interleukin-10 (IL10), phosphate and tension homology deleted on chromosome ten (PTEN); colon p-Akt and p-mTOR were increased. CONCLUSIONS: We found that BMSCs can induce Treg differentiation by inhibiting the Akt/mTOR pathway via PD-L1; this significantly improved symptoms and pathology in our ulcerative colitis rat models.


Subject(s)
Colitis , Mesenchymal Stem Cell Transplantation , Rats , Animals , Trinitrobenzenesulfonic Acid/toxicity , B7-H1 Antigen/genetics , T-Lymphocytes, Regulatory , RNA, Small Interfering , Proto-Oncogene Proteins c-akt , Rats, Sprague-Dawley , Colitis/chemically induced , Colitis/therapy , TOR Serine-Threonine Kinases , Phosphates/adverse effects , Bone Marrow Cells , Cell Differentiation
8.
Proc Natl Acad Sci U S A ; 116(9): 3678-3687, 2019 02 26.
Article in English | MEDLINE | ID: mdl-30733298

ABSTRACT

Infiltration of [Formula: see text] T lymphocytes into solid tumors is associated with good prognosis in various types of cancer, including triple-negative breast cancer (TNBC). However, the mechanisms underlying different infiltration levels are largely unknown. Here, we have characterized the spatial profile of [Formula: see text] T cells around tumor cell clusters (tightly connected tumor cells) in the core and margin regions in TNBC patient samples. We found that in some patients, the [Formula: see text] T cell density first decreases when moving in from the boundary of the tumor cell clusters and then rises again when approaching the center. To explain various infiltration profiles, we modeled the dynamics of T cell density via partial differential equations. We spatially modulated the diffusion/chemotactic coefficients of T cells (to mimic physical barriers) or introduced the localized secretion of a diffusing T cell chemorepellent. Combining the spatial-profile analysis and the modeling led to support for the second idea; i.e., there exists a possible chemorepellent inside tumor cell clusters, which prevents [Formula: see text] T cells from infiltrating into tumor cell clusters. This conclusion was consistent with an investigation into the properties of collagen fibers which suggested that variations in desmoplastic elements does not limit infiltration of [Formula: see text] T lymphocytes, as we did not observe significant correlations between the level of T cell infiltration and fiber properties. Our work provides evidence that [Formula: see text] T cells can cross typical fibrotic barriers and thus their infiltration into tumor clusters is governed by other mechanisms possibly involving a local repellent.


Subject(s)
CD8-Positive T-Lymphocytes/pathology , Lymphocytes, Tumor-Infiltrating/pathology , Triple Negative Breast Neoplasms/immunology , Adult , CD8-Positive T-Lymphocytes/immunology , Cell Count , Cell Line, Tumor , Cell Movement/genetics , Cell Movement/immunology , Female , Humans , Lymphocyte Count , Lymphocytes, Tumor-Infiltrating/immunology , Middle Aged , Triple Negative Breast Neoplasms/pathology
9.
Aging Ment Health ; 25(11): 2042-2052, 2021 11.
Article in English | MEDLINE | ID: mdl-33251822

ABSTRACT

In rural China, where families serve as critical safety-nets for their vulnerable members, grandparents play an essential role caring for the offspring of their migrant children. Evidence is mixed as to whether caring for grandchildren provides health benefits or incurs health risks. In this article, we used six waves of data from a study in rural China to examine the impact of caregiving for grandchildren on grandparents' emotional and cognitive health. Further, we examined financial transfers from adult children as a resource that potentially moderates the impact of high intensity caregiving on these outcomes. Data derived from six waves (2001-2015) of the Longitudinal Study of Older Adults in Anhui Province, China. We constructed 2,835 person-interval observations derived from 1,067 grandparents to examine lagged change in depressive symptoms and cognitive ability. Results show that caregiving frequency is not by itself harmful or beneficial to the emotional and cognitive health of grandparents, but it does appear to be harmful in the context of custodial care that is less economically supported by adult children. These results are discussed in terms of their relevance to intergenerational reciprocity in a filial culture, time-for-money exchange expectations, and the need for financial resources among caregiving grandparents in rural China.


Subject(s)
Grandparents , Aged , China , Cognition , Humans , Intergenerational Relations , Longitudinal Studies
10.
Genes Dev ; 24(9): 947-56, 2010 May.
Article in English | MEDLINE | ID: mdl-20439433

ABSTRACT

The loss of epithelial polarity is thought to play an important role during mammary tumor progression. Using a unique transgenic mouse model of ErbB2-induced mammary tumorigenesis, we demonstrated previously that amplification of ErbB2 is frequently accompanied by loss of the 14-3-3sigma gene. Here, we demonstrate that ectopic expression of 14-3-3sigma results in restoration of epithelial polarity in ErbB2-transformed mammary tumor cells. We further demonstrate that targeted deletion of 14-3-3sigma within primary mammary epithelial cells increases their proliferative capacity and adversely affects their ability to form polarized structures. Finally, we show that 14-3-3sigma can specifically form complexes with Par3, a protein that is essential for the maintenance of a polarized epithelial state. Taken together, these observations suggest that 14-3-3sigma plays a critical role in retaining epithelial polarity.


Subject(s)
14-3-3 Proteins/genetics , 14-3-3 Proteins/metabolism , Cell Polarity/genetics , Epithelial Cells/cytology , Animals , Cell Line, Tumor , Cell Proliferation , Down-Regulation , Female , Gene Expression Regulation, Neoplastic , Intercellular Junctions/genetics , Mammary Glands, Animal/cytology , Mice , Mice, Knockout
11.
Clin Gastroenterol Hepatol ; 15(11): 1724-1732, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28634136

ABSTRACT

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is the most common chronic gastrointestinal disorder, yet few drugs are effective in reducing symptoms. Approximately 50% of patients with IBS attempt herbal therapy at least once. We performed a randomized controlled trial to compare the efficacy of the herb formulation tongxie vs placebo or pinaverium (an antispasmodic agent) in reducing symptoms of IBS. METHODS: We performed a trial of 1044 adult patients with IBS (based on Rome III criteria) at 5 hospitals in China, from August 2012 through January 2015. Subjects were randomly assigned (1:1:1) to groups given tongxie (a combination of A macrocephalae, P lactiflora, C reticulata, S divaricata, C pilosula, C wenyujin, C medica, and P cocos, along with other herbs, based on patient features), placebo, or pinaverium (50 mg tablets) 3 times daily for 4 weeks. Primary end points were significantly greater reductions in abdominal pain and Bristol stool score (before vs after the 4-week study period) in patients given tongxie compared with patients given placebo or pinaverium. Secondary end points were reductions in pain and stool frequencies and abdominal discomfort and its frequency. RESULTS: Subjects given tongxie had significant reductions, before vs after the study period, in all 6 symptoms assessed, compared to patients given placebo (P < .001). A significantly higher proportion of patients given tongxie had increased stool consistency (75.6%) than patients given pinaverium (50.6%), and a significantly higher proportion of patients given tongxie had fewer daily stools (72.7%) than subjects given pinaverium (58.3%) (P < .001 for both). However, significantly higher proportions of patients given pinaverium had reduced pain (63.5%) and pain frequency (69.5%) than patients given tongxie (51.4% and 58.6%, respectively; P < .005 for both). CONCLUSIONS: In a randomized controlled trial of patients with IBS in China, we found 4 weeks of tongxie to produce significantly greater reduction in symptoms than placebo, and greater increases in stool consistency and reductions in stool frequency, than patients given pinaverium. Tongxie can therefore be considered an effective alternative therapy for patients with IBS who do not respond well to conventional therapies. Clinicaltrials.gov no: NCT01641224.


Subject(s)
Drugs, Chinese Herbal/administration & dosage , Irritable Bowel Syndrome/drug therapy , Abdominal Pain/physiopathology , Administration, Oral , Adolescent , Adult , Aged , Chemical Phenomena , China , Feces/chemistry , Female , Humans , Male , Middle Aged , Morpholines/administration & dosage , Placebos/administration & dosage , Treatment Outcome , Young Adult
12.
Biochem Biophys Res Commun ; 488(1): 6-14, 2017 06 17.
Article in English | MEDLINE | ID: mdl-28461115

ABSTRACT

MicroRNAs (miRNAs) play an important role in regulating immune system function by mRNA destabilisation or inhibition of translation. Recently, miR-155 was detected to be significantly up-regulated in colonic tissues of patients with active UC. However, it is unknown whether miR-155 is involved in the pathogenesis of UC and how it influences immune response in dextran sulfate sodium (DSS)-induced colitis mice. Here, we investigated the role of miR-155 in UC. Firstly, through bioinformatics analysis and luciferase report assay, we found Jarid2 was a direct target of miR-155; then, we carried out in situ hybridization, immunofluorescence and flow cytometry, and revealed that miR-155 levels were increased, Jarid2 levels were decreased and the frequency of Th17 cells was elevated in DSS-induced mice; we also used lentiviral vector to deliver miR-155 inhibition sequences to silence miR-155 that was effectively taken up by epithelial cells. MiR-155 inhibition attenuated DSS-induced colonic damage and inhibited Th17 cells differentiation. This study suggests that miR-155 plays a host-damaging role during DSS-induced colitis mice and induces Th17 differentiation by targeting Jarid2.


Subject(s)
Cell Differentiation/drug effects , Colitis/drug therapy , MicroRNAs/pharmacology , Polycomb Repressive Complex 2/metabolism , Th17 Cells/drug effects , Animals , Colitis/chemically induced , Dextran Sulfate , Male , Mice , Mice, Inbred BALB C , MicroRNAs/chemistry , MicroRNAs/genetics , Polycomb Repressive Complex 2/deficiency , Polycomb Repressive Complex 2/genetics , Structure-Activity Relationship , Th17 Cells/metabolism
13.
J Gastroenterol Hepatol ; 32(12): 1966-1974, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28370348

ABSTRACT

BACKGROUND AND AIM: Epithelial-mesenchymal transition (EMT), characterized by the decrease of E-cadherin (E-Cad) and increase in vimentin and alpha-smooth muscle actin (α-SMA), was demonstrated to participate in inflammatory bowel disease-related fibrosis. miR-200b plays an anti-fibrosis role in inhibiting EMT by targeting ZEB1 and ZEB2. But the stability of exogenous miR-200b in blood limits its application. Microvesicles (MVs), which can transfer miRNAs among cells and prevent them from degradation, may provide an excellent transport system for the delivery of miR-200b in the treatment of fibrosis. METHODS: Bone marrow mesenchymal stem cells (BMSCs) were transfected with lentivirus to overexpress miR-200b. The MVs packaged with miRNA-200b were harvested for the anti-fibrotic treatment using in vitro (transforming growth factor beta 1-mediated EMT in intestinal epithelial cells: IEC-6) and in vivo (TNBS-induced intestinal fibrosis in rats) models. The pathological morphology was observed, and the fibrosis related proteins, such as E-Cad, vimentin, α-SMA, ZEB1, and ZEB2, were detected. RESULTS: MiR-200b-MVs would significantly reverse the morphology in TGF-ß1-treated IEC-6 cells and improve the TNBS-induced colon fibrosis histologically. The treatment of miR-200b-MVs increased miR-200b levels both in the IEC-6 cells and colon, resulting in a significant prevention EMT and alleviation of fibrosis. The expression of E-Cad was increased, and the expressions of vimentin and α-SMA were decreased. ZBE1 and ZEB2, the targets of miR-200b, were also decreased. CONCLUSIONS: miR-200b could be transferred from genetically modified BMSCs to the target cells or tissue by MVs. The mechanisms of miR-200b-MVs in inhibiting colonic fibrosis were related to suppressing the development of EMT by targeting ZEB1and ZEB2.


Subject(s)
Cell-Derived Microparticles , Colitis/drug therapy , Colitis/physiopathology , Epithelial-Mesenchymal Transition/drug effects , Intestines/pathology , MicroRNAs/administration & dosage , MicroRNAs/physiology , Actins/metabolism , Animals , Cadherins/metabolism , Cells, Cultured , Colitis/pathology , Disease Models, Animal , Drug Delivery Systems , Epithelial-Mesenchymal Transition/genetics , Fibrosis , Homeodomain Proteins , Intestinal Mucosa/metabolism , Male , MicroRNAs/metabolism , MicroRNAs/pharmacology , Molecular Targeted Therapy , Rats, Sprague-Dawley , Transcription Factors , Vimentin/metabolism , Zinc Finger E-box-Binding Homeobox 1
14.
Proc Natl Acad Sci U S A ; 110(14): E1301-10, 2013 Apr 02.
Article in English | MEDLINE | ID: mdl-23509284

ABSTRACT

Triple-negative breast cancer (TNBC) accounts for ∼20% of cases and contributes to basal and claudin-low molecular subclasses of the disease. TNBCs have poor prognosis, display frequent mutations in tumor suppressor gene p53 (TP53), and lack targeted therapies. The MET receptor tyrosine kinase is elevated in TNBC and transgenic Met models (Met(mt)) develop basal-like tumors. To investigate collaborating events in the genesis of TNBC, we generated Met(mt) mice with conditional loss of murine p53 (Trp53) in mammary epithelia. Somatic Trp53 loss, in combination with Met(mt), significantly increased tumor penetrance over Met(mt) or Trp53 loss alone. Unlike Met(mt) tumors, which are histologically diverse and enriched in a basal-like molecular signature, the majority of Met(mt) tumors with Trp53 loss displayed a spindloid pathology with a distinct molecular signature that resembles the human claudin-low subtype of TNBC, including diminished claudins, an epithelial-to-mesenchymal transition signature, and decreased expression of the microRNA-200 family. Moreover, although mammary specific loss of Trp53 promotes tumors with diverse pathologies, those with spindloid pathology and claudin-low signature display genomic Met amplification. In both models, MET activity is required for maintenance of the claudin-low morphological phenotype, in which MET inhibitors restore cell-cell junctions, rescue claudin 1 expression, and abrogate growth and dissemination of cells in vivo. Among human breast cancers, elevated levels of MET and stabilized TP53, indicative of mutation, correlate with highly proliferative TNBCs of poor outcome. This work shows synergy between MET and TP53 loss for claudin-low breast cancer, identifies a restricted claudin-low gene signature, and provides a rationale for anti-MET therapies in TNBC.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Claudins/metabolism , Disease Models, Animal , Proto-Oncogene Proteins c-met/metabolism , Signal Transduction/physiology , Tumor Suppressor Protein p53/deficiency , Animals , Cells, Cultured , Female , Fluorescent Antibody Technique , Immunohistochemistry , Mice , Mice, Transgenic , Microarray Analysis , Proto-Oncogene Proteins c-met/genetics
15.
J Cell Sci ; 125(Pt 12): 2940-53, 2012 Jun 15.
Article in English | MEDLINE | ID: mdl-22366451

ABSTRACT

Invasive carcinoma cells form actin-rich matrix-degrading protrusions called invadopodia. These structures resemble podosomes produced by some normal cells and play a crucial role in extracellular matrix remodeling. In cancer, formation of invadopodia is strongly associated with invasive potential. Although deregulated signals from the receptor tyrosine kinase Met (also known as hepatocyte growth factor are linked to cancer metastasis and poor prognosis, its role in invadopodia formation is not known. Here we show that stimulation of breast cancer cells with the ligand for Met, hepatocyte growth factor, promotes invadopodia formation, and in aggressive gastric tumor cells where Met is amplified, invadopodia formation is dependent on Met activity. Using both GRB2-associated-binding protein 1 (Gab1)-null fibroblasts and specific knockdown of Gab1 in tumor cells we show that Met-mediated invadopodia formation and cell invasion requires the scaffold protein Gab1. By a structure-function approach, we demonstrate that two proline-rich motifs (P4/5) within Gab1 are essential for invadopodia formation. We identify the actin regulatory protein, cortactin, as a direct interaction partner for Gab1 and show that a Gab1-cortactin interaction is dependent on the SH3 domain of cortactin and the integrity of the P4/5 region of Gab1. Both cortactin and Gab1 localize to invadopodia rosettes in Met-transformed cells and the specific uncoupling of cortactin from Gab1 abrogates invadopodia biogenesis and cell invasion downstream from the Met receptor tyrosine kinase. Met localizes to invadopodia along with cortactin and promotes phosphorylation of cortactin. These findings provide insights into the molecular mechanisms of invadopodia formation and identify Gab1 as a scaffold protein involved in this process.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Breast Neoplasms/metabolism , Proto-Oncogene Proteins c-met/metabolism , Pseudopodia/metabolism , Signal Transduction , Adaptor Proteins, Signal Transducing/genetics , Breast Neoplasms/enzymology , Breast Neoplasms/genetics , Breast Neoplasms/physiopathology , Cell Line, Tumor , Cell Movement , Female , Humans , Neoplasm Invasiveness , Proto-Oncogene Proteins c-met/genetics , Pseudopodia/enzymology
16.
Neuro Oncol ; 26(6): 1052-1066, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38271182

ABSTRACT

BACKGROUND: Compared to minimally invasive brain metastases (MI BrM), highly invasive (HI) lesions form abundant contacts with cells in the peritumoral brain parenchyma and are associated with poor prognosis. Reactive astrocytes (RAs) labeled by phosphorylated STAT3 (pSTAT3) have recently emerged as a promising therapeutic target for BrM. Here, we explore whether the BrM invasion pattern is influenced by pSTAT3+ RAs and may serve as a predictive biomarker for STAT3 inhibition. METHODS: We used immunohistochemistry to identify pSTAT3+ RAs in HI and MI human and patient-derived xenograft (PDX) BrM. Using PDX, syngeneic, and transgenic mouse models of HI and MI BrM, we assessed how pharmacological STAT3 inhibition or RA-specific STAT3 genetic ablation affected BrM growth in vivo. Cancer cell invasion was modeled in vitro using a brain slice-tumor co-culture assay. We performed single-cell RNA sequencing of human BrM and adjacent brain tissue. RESULTS: RAs expressing pSTAT3 are situated at the brain-tumor interface and drive BrM invasive growth. HI BrM invasion pattern was associated with delayed growth in the context of STAT3 inhibition or genetic ablation. We demonstrate that pSTAT3+ RAs secrete Chitinase 3-like-1 (CHI3L1), which is a known STAT3 transcriptional target. Furthermore, single-cell RNA sequencing identified CHI3L1-expressing RAs in human HI BrM. STAT3 activation, or recombinant CHI3L1 alone, induced cancer cell invasion into the brain parenchyma using a brain slice-tumor plug co-culture assay. CONCLUSIONS: Together, these data reveal that pSTAT3+ RA-derived CHI3L1 is associated with BrM invasion, implicating STAT3 and CHI3L1 as clinically relevant therapeutic targets for the treatment of HI BrM.


Subject(s)
Astrocytes , Brain Neoplasms , Chitinase-3-Like Protein 1 , Neoplasm Invasiveness , STAT3 Transcription Factor , STAT3 Transcription Factor/metabolism , STAT3 Transcription Factor/genetics , Humans , Chitinase-3-Like Protein 1/metabolism , Chitinase-3-Like Protein 1/genetics , Animals , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Brain Neoplasms/genetics , Astrocytes/metabolism , Astrocytes/pathology , Mice , Mice, Transgenic , Cell Proliferation , Xenograft Model Antitumor Assays , Tumor Cells, Cultured
17.
J Biol Chem ; 287(11): 8048-59, 2012 Mar 09.
Article in English | MEDLINE | ID: mdl-22262855

ABSTRACT

Strict regulation of signaling by receptor tyrosine kinases (RTKs) is essential for normal biological processes, and disruption of this regulation can lead to tumor initiation and progression. Signal duration by the Met RTK is mediated in part by the E3 ligase Cbl. Cbl is recruited to Met upon kinase activation and promotes ubiquitination, trafficking, and degradation of the receptor. The Met RTK has been demonstrated to play a role in various types of cancer. Here, we show that Met-dependent loss of Cbl protein in MET-amplified gastric cancer cell lines represents another mechanism contributing to signal dysregulation. Loss of Cbl protein is dependent on Met kinase activity and is partially rescued with a proteasome inhibitor, lactacystin. Moreover, Cbl loss not only uncouples Met from Cbl-mediated negative regulation but also releases other Cbl targets, such as the EGF receptor, from Cbl-mediated signal attenuation. Thus, Met-dependent Cbl loss may also promote cross-talk through indirect enhancement of EGF receptor signaling.


Subject(s)
ErbB Receptors/metabolism , Proto-Oncogene Proteins c-cbl/metabolism , Proto-Oncogene Proteins c-met/metabolism , Signal Transduction , Stomach Neoplasms/enzymology , Cell Line, Tumor , Enzyme Activation/drug effects , Enzyme Activation/genetics , ErbB Receptors/genetics , HEK293 Cells , Humans , Proteasome Endopeptidase Complex/metabolism , Proteasome Inhibitors , Protein Transport/drug effects , Protein Transport/genetics , Proteolysis/drug effects , Proto-Oncogene Proteins c-cbl/genetics , Proto-Oncogene Proteins c-met/genetics , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Ubiquitination/drug effects , Ubiquitination/genetics
18.
J Gerontol B Psychol Sci Soc Sci ; 78(1): 99-110, 2023 01 28.
Article in English | MEDLINE | ID: mdl-35962777

ABSTRACT

OBJECTIVES: Participation in the Supplemental Nutrition Assistance Program (SNAP) among eligible adults aged 60 and older is much lower than among the younger population, and rates continue to decline throughout the life course while at the same time the risk of cognitive impairment increases. Due to the high administrative burden associated with SNAP application processes, cognitive impairment may be associated with low uptake of SNAP among the low-income older adult population, particularly among more socially disadvantaged groups (females, Blacks, and those living alone). We provide new evidence that changes in cognitive functioning are associated with reductions in the probability of SNAP take-up among eligible older adults. METHODS: Using panel data from the Health and Retirement Study, we estimate linear probability fixed-effects models to assess the effect of cognitive decline on the likelihood of SNAP participation among eligible adults aged 60 and older, controlling for observed characteristics that change over time as well as individual, time, and state fixed effects. RESULTS: Reduced levels of cognitive functioning that rise to the classification of dementia were strongly associated with reductions in the probability of SNAP take-up among eligible older adults. Results were particularly salient for females and those living alone. DISCUSSION: One barrier to SNAP take-up among older adults may be cognitive impairment with the size of effect differing by gender and living arrangement. Policymakers may want to consider initiatives to increase SNAP participation among older adults, including a focus on further simplification of eligibility and recertification processes that reduce administrative burden.


Subject(s)
Cognitive Dysfunction , Food Assistance , Female , Humans , United States/epidemiology , Middle Aged , Aged , Poverty , Retirement , Cognitive Dysfunction/epidemiology
19.
Health Aff (Millwood) ; 42(8): 1173-1181, 2023 08.
Article in English | MEDLINE | ID: mdl-37549333

ABSTRACT

The Supplemental Nutrition Assistance Program (SNAP) reduces food insecurity but is underused among many households. To increase SNAP participation, twenty-one states have adopted the standard medical deduction (SMD), which simplifies administrative requirements for eligible households (those with older adults or people with disabilities). However, to offset the costs of the SMD, states have reduced SNAP benefits elsewhere, raising concerns of negative spillover effects. Using national data from the period 2004-19 and a fixed-effects estimator, we found that the SMD was associated with increased SNAP participation among SMD-eligible households, in terms of aggregate household counts (20 percent) and as a share of households receiving SNAP (5 percentage points). Moreover, estimated annual SNAP benefits per state increased for SMD-eligible households but decreased (although not statistically significantly) for ineligible households. Offsetting SNAP costs may have benefited households with older adults and households with people with disabilities at the expense of others.


Subject(s)
Disabled Persons , Food Assistance , Humans , United States , Aged , Poverty , Family Characteristics , Costs and Cost Analysis , Food Supply
20.
J Clin Invest ; 133(7)2023 04 03.
Article in English | MEDLINE | ID: mdl-36795481

ABSTRACT

Activation of the tyrosine kinase c-Src promotes breast cancer progression and poor outcomes, yet the underlying mechanisms are incompletely understood. Here, we have shown that deletion of c-Src in a genetically engineered model mimicking the luminal B molecular subtype of breast cancer abrogated the activity of forkhead box M1 (FOXM1), a master transcriptional regulator of the cell cycle. We determined that c-Src phosphorylated FOXM1 on 2 tyrosine residues to stimulate its nuclear localization and target gene expression. These included key regulators of G2/M cell-cycle progression as well as c-Src itself, forming a positive feedback loop that drove proliferation in genetically engineered and patient-derived models of luminal B-like breast cancer. Using genetic approaches and small molecules that destabilize the FOXM1 protein, we found that targeting this mechanism induced G2/M cell-cycle arrest and apoptosis, blocked tumor progression, and impaired metastasis. We identified a positive correlation between FOXM1 and c-Src expression in human breast cancer and show that the expression of FOXM1 target genes predicts poor outcomes and associates with the luminal B subtype, which responds poorly to currently approved therapies. These findings revealed a regulatory network centered on c-Src and FOXM1 that is a targetable vulnerability in aggressive luminal breast cancers.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/pathology , Forkhead Box Protein M1/genetics , Forkhead Box Protein M1/metabolism , Cell Line, Tumor , Forkhead Transcription Factors/metabolism , Cell Proliferation , Cell Cycle/genetics , Gene Expression Regulation, Neoplastic
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