scholarly journals Abrupt transitions to tumor extinction: A quasispecies phenotypic model

2016 ◽  
Author(s):  
Josep Sardanyes ◽  
Regina Martinez ◽  
Carles Simo ◽  
Ricard Sole
Keyword(s):  
Tumor Cell ◽  
Fixed Points ◽  
Tumor Cells ◽  
Computational Models ◽  
Cell Populations ◽  
Model Parameters ◽  
Abrupt Transition ◽  
Quasispecies Model ◽  
Catastrophic Shift ◽  
Tumor Clearance

Background: The dynamics of heterogeneous tumor cell populations competing with healthy cells is an important topic in cancer research with deep implications in biomedicine. Multitude of theoretical and computational models have addressed this issue, especially focusing on the nature of the transitions governing tumor clearance as some relevant model parameters are tuned. In this contribution, we analyze a mathematical model of unstable tumor progression using the quasispecies framework. Our aim is to define a minimal model incorporating the dynamics of competition between healthy cells and a heterogeneous population of cancer cell phenotypes involving changes in replication-related genes (i.e., proto-oncogenes and tumor suppressor genes), in genes responsible for genomic stability, and in house-keeping genes. Such mutations or loss of genes result into different phenotypes with increased proliferation rates and/or increased genomic instabilities. Also, lethal phenotypes with mutations or loss of house-keeping genes are present in our model. Results: Despite bifurcations in the classical deterministic quasispecies model are typically given by smooth, continuous shifts (i.e., transcritical bifurcations), we here identify an novel type of abrupt transition causing tumor extinction. Such a bifurcation, named as trans-heteroclinic, is characterized by the exchange of stability between two distant fixed points (that do not collide) involving, respectively, tumor persistence and tumor clearance. The increase of mutation and/or the decrease of the replication rate of tumor cells involves this catastrophic shift of tumor cell populations. The transient times near bifurcation thresholds are also characterized, showing a power law dependence of exponent −1 of the transients as mutation is changed near the bifurcation value. Conclusions: An abrupt transition involving tumor clearance has been identified with a phenotypic quasispecies cancer model. This result is discussed in the context of targeted cancer therapy as a possible therapeutic strategy to force a catastrophic shift by delivering mutagenic and cytotoxic drugs inside tumor cells. Our model also reveals a novel mechanism causing a discontinuous transition given by the stability exchange of two distant fixed points, which we name as a trans-heteroclinic bifurcation.

scholarly journals Relevance of Circulating Hybrid Cells as a Non-Invasive Biomarker for Myriad Solid Tumors

2021 ◽  
Author(s):  
Matthew S. Dietz ◽  
Thomas L. Sutton ◽  
Brett S. Walker ◽  
Charles E. Gast ◽  
Luai Zarour ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cancer Patients ◽  
Solid Tumors ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Cell Population ◽  
Cancer Biology ◽  
Cell Populations ◽  
Hybrid Cells ◽  
Neoplastic Cells

AbstractMetastatic progression defines the final stages of tumor evolution and underlies the majority of cancer-related deaths. The heterogeneity in disseminated tumor cell populations capable of seeding and growing in distant organ sites contributes to the development of treatment resistant disease. We recently reported the identification of a novel tumor-derived cell population, circulating hybrid cells (CHCs), harboring attributes from both macrophages and neoplastic cells, including functional characteristics important to metastatic spread. These disseminated hybrids outnumber conventionally defined circulating tumor cells (CTCs) in cancer patients. It is unknown if CHCs represent a generalized cancer mechanism for cell dissemination, or if this population is relevant to the metastatic cascade. Herein, we detect CHCs in the peripheral blood of patients with cancer in myriad disease sites encompassing epithelial and non-epithelial malignancies. Further, we demonstrate that in vivo-derived hybrid cells harbor tumor-initiating capacity in murine cancer models and that CHCs from human breast cancer patients express stem cell antigens, features consistent with the ability to seed and grow at metastatic sites. Finally, we reveal heterogeneity of CHC phenotypes reflect key tumor features, including oncogenic mutations and functional protein expression. Importantly, this novel population of disseminated neoplastic cells opens a new area in cancer biology and renewed opportunity for battling metastatic disease.Simple SummaryThere is an incomplete understanding of circulating neoplastic cell populations and the fundamental mechanisms that drive dissemination, immune evasion, and growth —all critical information to more effectively prevent and treat cancer progression. A novel disseminated tumor cell population, circulating hybrid cells, are detected across many cancer types and carry functional tumor-initiating properties. Additionally, circulating hybrid cells are found at significantly higher levels than conventionally defined circulating tumor cells. Our study demonstrates that neoplastic hybrid cells harbor phenotypic and genetic characteristics of tumor and immune cells, display stem features, and are a generalizable phenomenon in solid tumors. Circulating hybrid cells therefore have relevance as a novel biomarker and open a new field of study in malignancy.

CLIA validation of a novel HER2 FISH test involving image-based cell-sorting to recover pure tumor cell populations from formalin fixed paraffin embedded tissue.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e12519-e12519
Author(s):  
Farideh Z. Bischoff ◽  
Amanda Gerber ◽  
Valeria Sero ◽  
Aditi Khurana ◽  
Marc Ting ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Single Cells ◽  
Chromosome 17 ◽  
Her2 Status ◽  
Cell Populations ◽  
Molecular Testing ◽  
Fish Analysis ◽  
Tumor Type ◽  
Her2 Positive

e12519 Background: The use of the DEPArray™ system to prepare pure tumor cell populations for more reliable and accurate downstream molecular sequence analysis has been previously demonstrated. To formally evaluate the utility of the DEPArray™ for sample preparation prior to molecular testing, we conducted a CLIA validation study to investigate the analytical performance of the instrument as well as accuracy in determining HER2 status in FFPE tumor specimens using a standard FISH assay. Methods: An initial cohort consisting of 93 FFPE samples (68 from Breast and 25 from Stomach) were selected based on defined inclusion criteria (tumor type and tumor content). For each sample, a single 50µm FFPE scroll was dissociated and then stained using fluorescently labeled Vimentin and Cytokeratin markers to distinguish between putative stromal and tumor populations, respectively. Following separation of these populations on the DEPArray™, a minimum of 100 single cells from each population was recovered and used for subsequent HER2 FISH testing. In addition, an H&E of each sample was evaluated by a Pathologist to confirm the presence of tumor content. Single-cell HER2-FISH analysis was then performed on the DEPArray™ processed samples to assess the number of signals present for each of the chromosome 17 and HER2 loci. Results were compared to the conventional tissue section FISH score. Results: Of the 93 specimens, 80 samples met pre-analytical acceptability criteria that were also confirmed by conventional methods to be either HER2-positive (n = 43) or HER2-negative (n = 37). Overall, a 95% concordance between HER2 results derived from the conventional as compared to the DEPArray™ method was observed. In addition, the instrument performance in terms of reproducibility and reliability was reported as 100%. Conclusions: DEPArray™ for preparation of FFPE-derived tumor cells was analytically validated and shown to yield high confidence in performing HER2-FISH analysis on recovered pure tumor cells. Current strategies to establish clinical utility and efficacy of this approach are underway for cases characterized as equivocal for HER2 or indeterminate by FISH.

scholarly journals Escape of mouse mastocytoma P815 after nearly complete rejection is due to antigen-loss variants rather than immunosuppression.

1983 ◽  
Vol 157 (3) ◽  
pp. 1040-1052 ◽  
Author(s):  
C Uyttenhove ◽  
J Maryanski ◽  
T Boon
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
T Lymphocyte ◽  
Cell Populations ◽  
Tumor Escape ◽  
Cytolytic T Lymphocyte ◽  
Complete Rejection ◽  
Antigen Loss

Even though mastocytoma P815 often undergoes a nearly complete rejection in syngeneic mice, the tumor cells almost always escape to form progressive tumors. We found that this was not due to the establishment of an immunosuppressed state because genetically marked P815 cells, that were injected in mice where tumor escape was occurring, were readily rejected. An analysis of escaping tumor cell populations with anti-P815 cytolytic T lymphocyte (CTL) clones showed the presence of stable resistant variants. Using antigen-loss variants found in escaping populations or selected in vitro with CTL clones, we were able to define four different tumor-associated antigenic specificities, each recognized by a specific CTL clone. One of these specificities was absent from all escaping tumor cells and another had been lost by some of them.

Interaction of Human Tumor Cells with Human Platelets and the Coagulation System

1983 ◽  
Vol 50 (03) ◽  
pp. 726-730 ◽  
Author(s):  
Hamid Al-Mondhiry ◽  
Virginia McGarvey ◽  
Kim Leitzel
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Human Tumor ◽  
Human Platelets ◽  
Factor Vii ◽  
Coagulation System ◽  
Breast Adenocarcinoma ◽  
Activate Factor ◽  
Tumor Cell Lines

SummaryThis paper reports studies on the interaction between human platelets, the plasma coagulation system, and two human tumor cell lines grown in tissue culture: Melanoma and breast adenocarcinoma. The interaction was monitored through the use of 125I- labelled fibrinogen, which measures both thrombin activity generated by cell-plasma interaction and fibrin/fibrinogen binding to platelets and tumor cells. Each tumor cell line activates both the platelets and the coagulation system simultaneously resulting in the generation of thrombin or thrombin-like activity. The melanoma cells activate the coagulation system through “the extrinsic pathway” with a tissue factor-like effect on factor VII, but the breast tumor seems to activate factor X directly. Both tumor cell lines activate platelets to “make available” a platelet- derived procoagulant material necessary for the conversion of prothrombin to thrombin. The tumor-derived procoagulant activity and the platelet aggregating potential of cells do not seem to be inter-related, and they are not specific to malignant cells.

scholarly journals Clusters, Assemblies and Aggregates of Tumor Cells in the Blood of Breast Cancer Patients; Composition, Mode of Action, Detection and Impact on Metastasis and Survival

2021 ◽  
Vol 1 (1) ◽  
pp. 55-68
Author(s):  
Urszula Smietanka ◽  
Małgorzata Szostakowska-Rodzos ◽  
Sylwia Tabor ◽  
Anna Fabisiewicz ◽  
Ewa A. Grzybowska
Keyword(s):  
Breast Cancer ◽  
Tumor Cell ◽  
Cancer Patients ◽  
Tumor Cells ◽  
Diagnostic Tool ◽  
Therapeutic Target ◽  
Mode Of Action ◽  
Breast Cancer Patients ◽  
Single Ctcs ◽  
Methods Of Isolation

Circulating tumor cells (CTCs) are gaining momentum as a diagnostic tool and therapeutic target. CTC clusters are more metastatic, but harder to study and characterize, because they are rare and the methods of isolation are mostly focused on single CTCs. This review highlights the recent advances to our understanding of tumor cell clusters with the emphasis on their composition, origin, biology, methods of detection, and impact on metastasis and survival. New approaches to therapy, based on cluster characteristics are also described.

108 MCY-M11, a CAR-PBMC cell product transiently expressing a mesothelin targeted mRNA CAR, exhibits desirable functional and immune phenotype attributed to sustained antitumor immunity in vitro

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A120-A120
Author(s):  
Sashi Kasimsetty ◽  
Himavanth Gatla ◽  
Dhana Chinnasamy
Keyword(s):  
T Cells ◽  
Tumor Cells ◽  
Antitumor Immunity ◽  
Memory T Cells ◽  
Cell Populations ◽  
Epitope Spreading ◽  
Antitumor Response ◽  
Cell Product

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

scholarly journals RGD4C peptide mediates anti-p21Ras scFv entry into tumor cells and produces an inhibitory effect on the human colon cancer cell line SW480

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chen-Chen Huang ◽  
Fang-Rui Liu ◽  
Qiang Feng ◽  
Xin-Yan Pan ◽  
Shu-Ling Song ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Membrane ◽  
Fusion Protein ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Fusion Proteins ◽  
Inhibitory Effect ◽  
Endosomal Escape ◽  
Antitumor Effects ◽  
Sw480 Cells

Abstract Background We prepared an anti-p21Ras scFv which could specifically bind with mutant and wild-type p21Ras. However, it cannot penetrate the cell membrane, which prevents it from binding to p21Ras in the cytoplasm. Here, the RGD4C peptide was used to mediate the scFv penetration into tumor cells and produce antitumor effects. Methods RGD4C-EGFP and RGD4C-p21Ras-scFv recombinant expression plasmids were constructed to express fusion proteins in E. coli, then the fusion proteins were purified with HisPur Ni-NTA. RGD4C-EGFP was used as reporter to test the factors affecting RGD4C penetration into tumor cell. The immunoreactivity of RGD4C-p21Ras-scFv toward p21Ras was identified by ELISA and western blotting. The ability of RGD4C-p21Ras-scFv to penetrate SW480 cells and colocalization with Ras protein was detected by immunocytochemistry and immunofluorescence. The antitumor activity of the RGD4C-p21Ras-scFv was assessed with the MTT, TUNEL, colony formation and cell migration assays. Chloroquine (CQ) was used an endosomal escape enhancing agent to enhance endosomal escape of RGD4C-scFv. Results RGD4C-p21Ras-scFv fusion protein were successfully expressed and purified. We found that the RGD4C fusion protein could penetrate into tumor cells, but the tumor cell entry of was time and concentration dependent. Endocytosis inhibitors and a low temperature inhibited RGD4C fusion protein endocytosis into cells. The change of the cell membrane potential did not affect penetrability. RGD4C-p21Ras-scFv could penetrate SW480 cells, effectively inhibit the growth, proliferation and migration of SW480 cells and promote this cells apoptosis. In addition, chloroquine (CQ) could increase endosomal escape and improve antitumor activity of RGD4C-scFv in SW480 cells. Conclusion The RGD4C peptide can mediate anti-p21Ras scFv entry into SW480 cells and produce an inhibitory effect, which indicates that RGD4C-p21Ras-scFv may be a potential therapeutic antibody for the treatment of ras-driven cancers.

scholarly journals Single-cell evaluation reveals shifts in the tumor-immune niches that shape and maintain aggressive lesions in the breast

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vidya C. Sinha ◽  
Amanda L. Rinkenbaugh ◽  
Mingchu Xu ◽  
Xinhui Zhou ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Mouse Model ◽  
Transition State ◽  
Tumor Cell ◽  
Single Cell ◽  
Tumor Cells ◽  
Breast Lesions ◽  
Aggressive Tumor ◽  
Insight Into

AbstractThere is an unmet clinical need for stratification of breast lesions as indolent or aggressive to tailor treatment. Here, single-cell transcriptomics and multiparametric imaging applied to a mouse model of breast cancer reveals that the aggressive tumor niche is characterized by an expanded basal-like population, specialization of tumor subpopulations, and mixed-lineage tumor cells potentially serving as a transition state between luminal and basal phenotypes. Despite vast tumor cell-intrinsic differences, aggressive and indolent tumor cells are functionally indistinguishable once isolated from their local niche, suggesting a role for non-tumor collaborators in determining aggressiveness. Aggressive lesions harbor fewer total but more suppressed-like T cells, and elevated tumor-promoting neutrophils and IL-17 signaling, disruption of which increase tumor latency and reduce the number of aggressive lesions. Our study provides insight into tumor-immune features distinguishing indolent from aggressive lesions, identifies heterogeneous populations comprising these lesions, and supports a role for IL-17 signaling in aggressive progression.

scholarly journals Loss of cIAP1 in Endothelial Cells Limits Metastatic Extravasation through Tumor-Derived Lymphotoxin Alpha

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 599
Author(s):  
Lazaros Vasilikos ◽  
Kay Hänggi ◽  
Lisanne M. Spilgies ◽  
Samanta Kisele ◽  
Stefanie Rufli ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Advanced Disease ◽  
Disease Stage ◽  
Stromal Compartment ◽  
Tumor Load ◽  
Smac Mimetics ◽  
Advanced Disease Stage ◽  
Lymphotoxin Alpha ◽  
Open Question

In this study, we determined whether Smac mimetics play a role in metastasis, specifically in circulation, tumor extravasation and growth in a metastatic site. Reports suggest inducing the degradation of IAPs through use of Smac mimetics, alters the ability of the tumor cell to metastasize. However, a role for the immune or stromal compartment in affecting the ability of tumor cells to metastasize upon loss of IAPs has not been defined. To address this open question, we utilized syngeneic tumor models in a late-stage model of metastasis. Loss of cIAP1 in the endothelial compartment, rather than depletion of cIAP2 or absence of cIAP1 in the hematopoietic compartment, caused reduction of tumor load in the lung. Our results underline the involvement of the endothelium in hindering tumor cell extravasation upon loss of cIAP1, in contrast to the immune compartment. Endothelial specific depletion of cIAP1 did not lead to cell death but resulted in an unresponsive endothelium barrier to permeability factors causing a decrease in tumor cell extravasation. Surprisingly, lymphotoxin alpha (LTA), and not TNF, secreted by the tumor cells, was critical for the extravasation. Using TCGA, we found high LTA mRNA expression correlated with decreased survival in kidney carcinoma and associated with advanced disease stage. Our data suggest that Smac mimetics, targeting cIAP1/2, reduce metastasis to the lung by inhibiting tumor cell extravasation.

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