scholarly journals Tumor cell–organized fibronectin maintenance of a dormant breast cancer population

2020 ◽  
Vol 6 (11) ◽  
pp. eaaz4157 ◽  
Author(s):  
Lauren E. Barney ◽  
Christopher L. Hall ◽  
Alyssa D. Schwartz ◽  
Akia N. Parks ◽  
Christopher Sparages ◽  
...  

Tumors can undergo long periods of dormancy, with cancer cells entering a largely quiescent, nonproliferative state before reactivation and outgrowth. To understand the role of the extracellular matrix (ECM) in regulating tumor dormancy, we created an in vitro cell culture system with carefully controlled ECM substrates to observe entrance into and exit from dormancy with live imaging. We saw that cell populations capable of surviving entrance into long-term dormancy were heterogeneous, containing quiescent, cell cycle–arrested, and actively proliferating cells. Cell populations capable of entering dormancy formed an organized, fibrillar fibronectin matrix via αvβ3 and α5β1 integrin adhesion, ROCK-generated tension, and TGFβ2 stimulation, and cancer cell outgrowth after dormancy required MMP-2–mediated fibronectin degradation. We propose this approach as a useful, in vitro method to study factors important in regulating dormancy, and we used it here to elucidate a role for fibronectin deposition and MMP activation.

2019 ◽  
Author(s):  
Lauren E. Barney ◽  
Christopher L. Hall ◽  
Alyssa D. Schwartz ◽  
Akia N. Parks ◽  
Christopher Sparages ◽  
...  

AbstractTumors can undergo long periods of dormancy, with cancer cells entering a largely quiescent, non-proliferative state before reactivation and outgrowth. For a patient, these post-remission tumors are often drug resistant and highly aggressive, resulting in poor prognosis. To understand the role of the extracellular matrix (ECM) in regulating tumor dormancy, we created anin vitrocell culture system that combines carefully controlled ECM substrates with nutrient deprivation to observe entranceintoand exitfromdormancy with live imaging. We saw that cell populations capable of surviving entrance into long-term dormancy were heterogeneous, containing quiescent, cell cycle arrested, and actively proliferating cells. Cell populations that endured extended periods of serum-deprivation-induced dormancy formed an organized, fibrillar fibronectin matrix via αvβ3and α5β1integrin adhesion, ROCK-generated tension, and TGFβ2 stimulation. We surmised that the fibronectin matrix was primarily a mediator of cell survival, not proliferation, during the serum-deprivation stress, bacause cancer cell outgrowth after dormancy required MMP-2-mediated fibronectin degradation. Given the difficulty of animal models in observing entrance and exit from dormancy in real-time, we propose this approach as a new,in vitromethod to study factors important in regulating dormancy, and we used it here to elucidate a role for fibronectin deposition and MMP activation.


Parasitology ◽  
1999 ◽  
Vol 118 (3) ◽  
pp. 235-244 ◽  
Author(s):  
T. JÄKEL ◽  
C. ARCHER-BAUMANN ◽  
A. M. BOEHMLER ◽  
I. SORGER ◽  
M. HENKE ◽  
...  

The affinity of merozoites of Sarcocystis singaporensis obtained from the lungs of acutely infected rats to muscle cells and other cell lines grown in vitro was examined. Two distinct types of mature schizonts developed in the lungs 11–13 days p.i. with sporocysts: those containing PAS− merozoites (type 1) which mainly reacted with antibodies prepared against sporozoites, and others containing PAS+ merozoites (type 2) which were antigenically close to bradyzoites. When inoculated onto cell cultures, type 1-merozoites induced schizogonic development in brain capillary endothelial cells of the rat. In contrast, type 2-merozoites invaded L6 myoblasts. In long-term cultures (50 days) of L6 cells, zoites transformed to a 8–15 μm long uninucleate stage which, tentatively, could be unizoite sarcocysts. Although the observed dichotomy in merozoite development is unprecedented in this form, evidence from previous work suggests that these observations are relevant to other Sarcocystis species. The presented cell culture system could be a first step towards successful growth of sarcocysts in vitro.


2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Kajohnkiart Janebodin ◽  
Worakanya Buranaphatthana ◽  
Nicholas Ieronimakis ◽  
Aislinn L. Hays ◽  
Morayma Reyes

Despite a pivotal role in salivary gland development, homeostasis, and disease, the role of salivary gland mesenchyme is not well understood. In this study, we used theCol1a1-GFPmouse model to characterize the salivary gland mesenchymein vitroandin vivo. TheCol1a1-GFPtransgene was exclusively expressed in the salivary gland mesenchyme.Ex vivoculture of mixed salivary gland cells in DMEM plus serum medium allowed long-term expansion of salivary gland epithelial and mesenchymal cells. The role of TGF-β1 in salivary gland development and disease is complex. Therefore, we used thisin vitroculture system to study the effects of TGF-β1 on salivary gland cell differentiation. TGF-β1 induced the expression of collagen, and inhibited the formation of acini-like structures in close proximity to mesenchymal cells, which adapted a fibroblastic phenotype. In contrast, TGF-βR1 inhibition increased acini genes and fibroblast growth factors (Fgf-7andFgf-10), decreased collagen and induced formation of larger, mature acini-like structures. Thus, inhibition of TGF-βsignaling may be beneficial for salivary gland differentiation; however, due to differential effects of TGF-β1 in salivary gland epithelial versus mesenchymal cells, selective inhibition is desirable. In conclusion, this mixed salivary gland cell culture system can be used to study epithelial-mesenchymal interactions and the effects of differentiating inducers and inhibitors.


2009 ◽  
Vol 16 (3) ◽  
pp. 819-834 ◽  
Author(s):  
Maya Dadiani ◽  
Dalia Seger ◽  
Tamar Kreizman ◽  
Daria Badikhi ◽  
Raanan Margalit ◽  
...  

The role of c-Myc in estrogen regulation of vascular endothelial growth factor (VEGF) and of the vasculature function has been investigated in breast cancer cells and tumors. The studies were performed on MCF7 wild-type cells and MCF7-35im clone, stably transfected with an inducible c-Myc gene. In vitro and ex vivo methods for investigating molecular events were integrated with in vivo magnetic resonance imaging of the vascular function. The results showed that the c-Myc upregulation by estrogen is necessary for the transient induction of VEGF transcription; however, overexpression of c-Myc alone is not sufficient for this induction. Furthermore, both c-Myc and the activated estrogen receptor α (ERα) were shown to co-bind the VEGF promoter in close proximity, indicating a novel mechanism for estrogen regulation of VEGF. Studies of long-term estrogen treatment and overexpression of c-Myc alone demonstrated regulation of stable VEGF expression levels in vitro and in vivo, maintaining steady vascular permeability in tumors. However, withdrawal of estrogen from the tumors resulted in increased VEGF and elevated vascular permeability, presumably due to hypoxic conditions that were found to dominate VEGF overexpression in cultured cells. This work revealed a cooperative role for ERα and c-Myc in estrogen regulation of VEGF and the ability of c-Myc to partially mimic estrogen regulation of angiogenesis. It also illuminated the differences in estrogen regulation of VEGF during transient and long-term sustained treatments and under different microenvironmental conditions, providing a complementary picture of the in vitro and in vivo results.


2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors


Author(s):  
Xuehui Wang ◽  
Changle Ji ◽  
Jiashu Hu ◽  
Xiaochong Deng ◽  
Wenfang Zheng ◽  
...  

Abstract Background Circular RNAs (circRNAs), a novel class of endogenous RNAs, have shown to participate in the development of breast cancer (BC). Hsa_circ_0005273 is a circRNA generated from several exons of PTK2. However, the potential functional role of hsa_circ_0005273 in BC remains largely unknown. Here we aim to evaluate the role of hsa_circ_0005273 in BC. Methods The expression level of hsa_circ_0005273 and miR-200a-3p were examined by RT-qPCR in BC tissues and cell lines. The effect of knocking down hsa_circ_0005273 in BC cell lines were evaluated by examinations of cell proliferation, migration and cell cycle. In addition, xenografts experiment in nude mice were performed to evaluate the effect of hsa_circ_0005273 in BC. RNA immunoprecipitation assay, RNA probe pull-down assay, luciferase reporter assay and fluorescence in situ hybridization were conducted to confirm the relationship between hsa_circ_0005273, miR-200a-3p and YAP1. Results Hsa_circ_0005273 is over-expressed in BC tissues and cell lines, whereas miR-200a-3p expression is repressed. Depletion of hsa_circ_0005273 inhibited the progression of BC cells in vitro and in vivo, while overexpression of hsa_circ_0005273 exhibited the opposite effect. Importantly, hsa_circ_0005273 upregulated YAP1 expression and inactivated Hippo pathway via sponging miR-200a-3p to promote BC progression. Conclusions Hsa_circ_0005273 regulates the miR-200a-3p/YAP1 axis and inactivates Hippo signaling pathway to promote BC progression, which may become a potential biomarker and therapeutic target.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A120-A120
Author(s):  
Sashi Kasimsetty ◽  
Himavanth Gatla ◽  
Dhana Chinnasamy

BackgroundMCY-M11, an anti-mesothelin CAR (Meso-CAR) mRNA transfected PBMC cell product manufactured through <1 day-process is under clinical evaluation for the treatment of advanced ovarian cancer and peritoneal mesothelioma. In this in-vitro study, we characterized the phenotypic and functional status of immune cell populations in MCY-M11 and their possible role in antitumor immunity.MethodsMCY-M11 cell product were generated using unmanipulated healthy donor PBMCs (n=5) by transfection of Meso-CAR mRNA using MaxCyte’s proprietary Flow Electroporation® system. Frozen MCY-M11 cell product was thawed and cultured for 18 hours, then co-cultured with hMSLNneg or hMSLNpos human mesothelioma cell line, MSTO-211H, or stimulated with anti-CD3/anti-CD28 antibodies in vitro for 8 days. Distinct cell populations in MCY-M11 were evaluated for kinetics and duration of CAR expression, differentiation, activation, exhaustion, and their ability to secrete various immunomodulatory molecules during in vitro stimulation. Antigen-specific proliferation and cytotoxicity of MCY-M11 against hMSLNpos tumor cells as well as their ability to mount long-term antitumor immunity through epitope spreading mechanisms were studied.ResultsIndividual cell populations in MCY-M11 exhibited a consistent but transient Meso-CAR expression persisting for about 7 days. Cell subsets in MCY-M11 acquired early signs of activation and differentiation within 18–24 hours post-culture, but only attained full activation and lineage-specific differentiation upon specific response to hMSLNpos tumor cells. hMSLN antigen experienced MCY-M11 retained significant fractions of Naïve and Central Memory T cells and increased percentage of Effector Memory T cells along with increased expression of CD62L, CD27, and chemokine receptors (CCR5, CCR7, and CXCR3). MCY-M11 exhibited strong antigen-specific cytotoxicity against hMSLNpos tumor cells with corresponding increase in activation and proliferation of CD4+ and CD8+ T cell subsets and displayed low or no acquisition of known exhaustion markers. NK cells also exhibited a functionally superior molecular signature exhibiting increased levels of NKG2D, NKp44, NKp46, FAS, and TRAIL. The Monocytes and B cells in MCY-M11 also acquired an activated, differentiated, and mature phenotype, expressing molecules required for antigen presentation (HLA-DR, HLA-ABC, and CD205) and T cell co-stimulation (CD80 and CD86) to mount a strong antitumor response. These phenotypic changes in cell subsets of MCY-M11 transpired with simultaneous secretion of potent immunostimulatory molecules and chemokines facilitating an extended antitumor response through epitope spreading.ConclusionsWe demonstrated that MCY-M11 is a unique cell product possessing a complete built-in immune cellular machinery with favorable phenotype and enhanced functions specialized in mediating an effective and long-term antitumor response.Trial RegistrationNCT03608618


Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.


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