scholarly journals Human platelets exert cytotoxic effects on tumor cells

Blood ◽  
1985 ◽  
Vol 65 (5) ◽  
pp. 1252-1255 ◽  
Author(s):  
GM Ibele ◽  
NE Kay ◽  
GJ Johnson ◽  
HS Jacob
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Types ◽  
Human Platelets ◽  
Fixed Number ◽  
Cell Cytotoxicity ◽  
Lipoxygenase Inhibitor ◽  
Tumor Metastases

Abstract Monocytes are thought to play a role in host resistance to tumor cell growth in animals and humans. In addition, platelets are known to be involved in tumor metastases. To investigate the interaction of these two cell types and their effect on tumor cells, human monocytes and platelets were examined using an in vitro monocyte-tumor cell cytotoxicity assay. Monocytes alone resulted in 32% +/- 1.5 (mean +/- SEM) tumor cell kill. When platelets were added to monocytes in a 1:1 ratio, an increase in cytotoxicity to 61% +/- 3.2 was observed. The cytotoxicity noted when platelets were added to a fixed number of monocytes and tumor cells was dependent on the number of platelets added. A decrease in cytotoxicity from 32% +/- 1.5 to 12% +/- 2.3 was observed when contaminating platelets were removed from monocyte preparations. Platelets added to tumor cells in the absence of any monocytes were also toxic, resulting in a maximum kill of 95% at a 4:1 platelet/tumor cell ratio. Secreted products of freshly isolated platelets may be responsible for much of the observed cytotoxicity, since supernatants from the platelets were toxic for tumor cells. Platelets pretreated with a cyclooxygenase inhibitor (ASA) or a lipoxygenase inhibitor had decreased cytotoxicity compared with untreated platelets. Our results indicate that products of platelet arachidonate metabolism are toxic for tumor cell lines. They also suggest that the role of the platelet must be considered when studying monocyte-tumor cell cytotoxicity.

scholarly journals Human platelets exert cytotoxic effects on tumor cells

Blood ◽  
1985 ◽  
Vol 65 (5) ◽  
pp. 1252-1255
Author(s):  
GM Ibele ◽  
NE Kay ◽  
GJ Johnson ◽  
HS Jacob
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Types ◽  
Human Platelets ◽  
Fixed Number ◽  
Cell Cytotoxicity ◽  
Lipoxygenase Inhibitor ◽  
Tumor Metastases

Monocytes are thought to play a role in host resistance to tumor cell growth in animals and humans. In addition, platelets are known to be involved in tumor metastases. To investigate the interaction of these two cell types and their effect on tumor cells, human monocytes and platelets were examined using an in vitro monocyte-tumor cell cytotoxicity assay. Monocytes alone resulted in 32% +/- 1.5 (mean +/- SEM) tumor cell kill. When platelets were added to monocytes in a 1:1 ratio, an increase in cytotoxicity to 61% +/- 3.2 was observed. The cytotoxicity noted when platelets were added to a fixed number of monocytes and tumor cells was dependent on the number of platelets added. A decrease in cytotoxicity from 32% +/- 1.5 to 12% +/- 2.3 was observed when contaminating platelets were removed from monocyte preparations. Platelets added to tumor cells in the absence of any monocytes were also toxic, resulting in a maximum kill of 95% at a 4:1 platelet/tumor cell ratio. Secreted products of freshly isolated platelets may be responsible for much of the observed cytotoxicity, since supernatants from the platelets were toxic for tumor cells. Platelets pretreated with a cyclooxygenase inhibitor (ASA) or a lipoxygenase inhibitor had decreased cytotoxicity compared with untreated platelets. Our results indicate that products of platelet arachidonate metabolism are toxic for tumor cell lines. They also suggest that the role of the platelet must be considered when studying monocyte-tumor cell cytotoxicity.

scholarly journals Induction of Apoptosis of Metastatic Mammary Carcinoma Cells In Vivo by Disruption of Tumor Cell Surface CD44 Function

1997 ◽  
Vol 186 (12) ◽  
pp. 1985-1996 ◽  
Author(s):  
Qin Yu ◽  
Bryan P. Toole ◽  
Ivan Stamenkovic
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Lung Tissue ◽  
Mammary Carcinoma ◽  
Cell Types ◽  
Pulmonary Endothelium ◽  
Soluble Cd44

To understand how the hyaluronan receptor CD44 regulates tumor metastasis, the murine mammary carcinoma TA3/St, which constitutively expresses cell surface CD44, was transfected with cDNAs encoding soluble isoforms of CD44 and the transfectants (TA3sCD44) were compared with parental cells (transfected with expression vector only) for growth in vivo and in vitro. Local release of soluble CD44 by the transfectants inhibited the ability of endogenous cell surface CD44 to bind and internalize hyaluronan and to mediate TA3 cell invasion of hyaluronan-producing cell monolayers. Mice intravenously injected with parental TA3/St cells developed massive pulmonary metastases within 21–28 d, whereas animals injected with TA3sCD44 cells developed few or no tumors. Tracing of labeled parental and transfectant tumor cells revealed that both cell types initially adhered to pulmonary endothelium and penetrated the interstitial stroma. However, although parental cells were dividing and forming clusters within lung tissue 48 h following injection, >80% of TA3sCD44 cells underwent apoptosis. Although sCD44 transfectants displayed a marked reduction in their ability to internalize and degrade hyaluronan, they elicited abundant local hyaluronan production within invaded lung tissue, comparable to that induced by parental cells. These observations provide direct evidence that cell surface CD44 function promotes tumor cell survival in invaded tissue and that its suppression can induce apoptosis of the invading tumor cells, possibly as a result of impairing their ability to penetrate the host tissue hyaluronan barrier.

scholarly journals Tumor quiescence: elevating SOX2 in diverse tumor cell types downregulates a broad spectrum of the cell cycle machinery and inhibits tumor growth

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ethan P. Metz ◽  
Erin L. Wuebben ◽  
Phillip J. Wilder ◽  
Jesse L. Cox ◽  
Kaustubh Datta ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Cell Cycle Machinery

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.

scholarly journals Hepatocyte-tumor cell interaction in vitro. I. Conditions for rosette formation and inhibition by anti-H-2 antibody.

1980 ◽  
Vol 151 (4) ◽  
pp. 984-989 ◽  
Author(s):  
V Schirrmacher ◽  
R Cheingsong-Popov ◽  
H Arnheiter
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Metastatic Tumor ◽  
Cell Interaction ◽  
Rosette Formation ◽  
Normal Cells ◽  
Neuraminidase Treatment

Murine hepatocytes, isolated by an in situ collagenase-perfusion technique and cultured in Petri dishes, were shown to form rosettes with liver-metastasizing syngeneic tumor cells. Pretreatment of the tumor cells with neuraminidase generally increased the binding, whereas pretreatment of the liver cells with neuraminidase abolished the binding completely. The tumor-cell binding may be mediated by the previously described lectin-like receptor of hepatocytes that also was sensitive to neuraminidase treatment and that bound desialylated cells better than normal cells. Anti-H-2 sera could efficiently inhibit the rosette formation of metastatic tumor cells with the hepatocytes, which points to a possible role of H-2 molecules in this interaction of neoplastic and normal cells.

scholarly journals Activation of the NF-κB Signaling Pathway Promotes Malignancy in Bladder Cancer Cells in a Positive Feedback Manner

2020 ◽  
Author(s):  
Zhenfeng guan ◽  
Yi Sun ◽  
YaZhuo Jiang ◽  
Xinyang Wang ◽  
Jinhai Fan
Keyword(s):  
Bladder Cancer ◽  
Endothelial Cells ◽  
Tumor Cell ◽  
Tumor Progression ◽  
Signaling Pathway ◽  
Tumor Cells ◽  
Positive Feedback ◽  
Umbilical Vein

Abstract Background: The main issue arising from bladder cancer (BCa) is the high relapse ratio and tumor progression, the mechanism of which remains to be elucidated. Interaction of tumor cells with the stroma of microenvironment promoting tumor progression warrants much attention from researchers. Among all stromal cells, endothelial cells (ECs) are exceptional. Numerous studies have investigated its role of angiogenesis, but have not studied immunocyte recruitment and chemokine secretion, the important significance of which in tumor progression has been proven. Meanwhile, to the best of our knowledge, few studies have focused on the direct interaction between tumor cells and ECs in BCa tissue, which was the aim of the present study. Methods: In the present study, immunohistochemical staining is used for detecting the distribution of ECs in BCa tissue, and we use SPSS 19 to analysis the relationship between ECs distribution and tumor grade/stage; inadition, co-curlturing of tumor cell with ECs is usd to mimicking the interaction of tumor cell with ECs, followed by Chamber Assay, BrdU incorporoartion, WB, Qt-PCR, ect, to investiatin the mechanism. Results: The distribution of ECs in BCa tissue is significantly increased according to BCa grade and negatively associated to the time from BCa diagnosis to progression, manifesting as an independent risk factor for BCa prognosis. The following in vitro experiment indicates that the conditional medium from co-culture of tumor cells (T24/J82) with ECs (human umbilical vein endothelial cells, which were used as ECs in the in vitro experiment) contributes to the activation of the NF-ĸB signaling pathway in tumor cells, leading to the upregulation of CXCL1/8. This further results in enhanced tumor cell malignancy and EC recruitment, manifested as a positive feedback loop. Conclusions: The present study provided a further understanding on the role of ECs in BCa progression—not only by angiogenesis but also by interacting with tumor cell dirctly.

p125 focal adhesion kinase promotes malignant astrocytoma cell proliferation in vivo

2000 ◽  
Vol 113 (23) ◽  
pp. 4221-4230 ◽  
Author(s):  
D. Wang ◽  
J.R. Grammer ◽  
C.S. Cobbs ◽  
J.E. Stewart ◽  
Z. Liu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Focal Adhesion ◽  
Fold Increase ◽  
Astrocytic Tumor ◽  
Malignant Astrocytoma

p125 focal adhesion kinase (p125FAK) is a cytoplasmic tyrosine kinase that is activated upon engagement of integrin cell adhesion receptors, and initiates several signaling events that modulate cell function in vitro. To determine the biologic role of p125FAK in malignant astrocytic tumor cells, U-251MG human malignant astrocytoma cells were stably transfected with p125FAK cDNA using the TET-ON system, and stable clones isolated that exhibited an estimated 5- or 20-fold increase in p125FAK expression on administration of 0.1 or 2.0 microg/ml doxycycline, respectively. In vitro studies demonstrated that induction of p125FAK resulted in a 2- to 3-fold increase in cell migration, increased p130CAS phosphorylation, localization of exogenous p125FAK to focal adhesions, and a 2-fold increase in soft agar growth. To determine the role of p125FAK in vivo, clones were injected stereotactically into the brains of scid mice. A 4.5-fold estimated increase in p125FAK expression was induced by administration of doxycycline in the drinking water. Analysis of xenograft brains demonstrated that, upon induction of p125FAK, there was a 1.6- to 2.8-fold increase in tumor cell number, and an increase in mAb PCNA-labeling of tumor cells in the absence of a change in the apoptotic index. Compared to normal brain, the expression of p125FAK was elevated in malignant astrocytic tumor biopsies from patient samples. These data demonstrate for the first time that p125FAK promotes tumor cell proliferation in vivo, and that the underlying mechanism is not associated with a reduction in apoptosis.

Platelets, Tumor Cell Invasiveness, and Metastasis

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. SCI-31-SCI-31
Author(s):  
Richard O. Hynes ◽  
Shahinoor Begum ◽  
Myriam Labelle
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Conflicts Of Interest ◽  
Cell Types ◽  
Therapeutic Interventions ◽  
Migration And Invasion ◽  
Cell Contact ◽  
Cell Arrest

Abstract Platelets have long been known to promote metastasis, and multiple mechanisms have been proposed to explain this phenomenon, including adhesion, coagulation, and protection against natural killer (NK) cells or turbulence. One mechanism that has been little explored is the possibility that platelets might secrete growth factors or provide other stimuli that could enhance the malignant properties of tumor cells. We have shown that pretreatment of carcinoma cells with platelets induces an EMT-like transformation in their properties in vitro and renders them much more metastatic after introduction into mice. TGF-β, produced by platelets and released on their activation is essential for both the in vitro and the in vivo effects. However, TGF-β alone is insufficient; platelet-tumor cell contact is also required and this contact activates NFkB signaling, which synergizes with the TGF-β signaling. Both signals are required for the enhancement of metastasis. In addition to enhancing migration and invasion in vitro, platelets enhance extravasation in vivo. Earlier work has shown that both P-selectin (expressed on platelets) and L-selectin (expressed on leukocytes) are essential for efficient metastasis, and aggregates of tumor cells, platelets, and leukocytes can be observed at sites of tumor cell arrest and extravasation. It has also been demonstrated by others that leukocytes can enhance extravasation and metastatic seeding. Therefore, we have been interested in the question of the relative roles of platelets and leukocytes in these processes. Which cell types are recruited at the sites of metastatic seeding? Does one cell type depend on another? Which cell types enhance metastasis? What roles do the platelets play in recruiting the other cell types? The involvement of platelets in enhancing metastasis also raises questions about the effects of platelets on circulating tumor cells (CTCs). Could platelets enhance the metastatic capacity of CTCs? Could it be the case that only those CTCs that are associated with platelets and/or leukocytes are functionally involved in seeding metastases? Such aggregates are not scored in most current assays for CTCs and will require new investigative approaches. Platelet participation in metastasis also raises the possibility of therapeutic interventions targeting platelet-specific targets and the paracrine interactions between them and other cells. Disclosures: No relevant conflicts of interest to declare.

Protease Activated Receptor-1 (PAR-1) Impedes Tumor Progression

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2560-2560
Author(s):  
Gregory N. Adams ◽  
Haley Weston ◽  
Leah Rosenfeldt ◽  
Malinda Frederick ◽  
Joseph S. Palumbo
Keyword(s):  
Cell Proliferation ◽  
Tumor Growth ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Prostate Tumor ◽  
Protease Activated Receptor 1 ◽  
Tumor Types ◽  
And Control

Abstract Activation of cell signaling by thrombin through Protease Activated Receptor-1 (PAR-1) represents one important interface between blood coagulation and cell activation in response to injury and inflammation. In the context of cancer, PAR-1 has been suggested to promote tumor growth through mechanisms coupled to tumor cell proliferation, tumor cell migration, and the development of a supportive tumor stroma. Consistent with this view, both tumor cells and stromal cells express high levels of PAR-1, and elevated PAR-1 expression has been correlated with a poor prognosis across several tumor types. In the current studies, we tested the hypothesis that PAR-1 is a critical driver of tumorigenesis and tumor growth using murine models of genetically-induced prostate and intestinal tumor growth. To define the role of PAR-1 in prostate tumor progression, we interbred mice expressing the TRAMP transgene (transgenic adenocarcinoma of the mouse prostate; SV40 Large T antigen under the control of a probasin promoter) to PAR-1-deficient mice (PAR-1-/-) in order to generate male TRAMP mice with and without PAR-1 expression for detailed analyses of prostate tumor growth. Surprisingly, prostate tumors harvested from PAR-1-/- mice were significantly larger than those harvested from PAR-1+/+ mice. In order to begin to address the PAR-1 expressing cellular compartments responsible for prostate tumor inhibition, we subcutaneously inoculated immunocompetent C57Bl/6-derived PAR-1-/- and control mice with tumor cells derived from a C57Bl/6 TRAMP mouse. TRAMP-derived tumors grew indistinguishably in PAR-1-/- and control mice, suggesting that stromal-cell associated PAR-1 is dispensable for prostate tumor growth. We next tested the effect of tumor cell-intrinsic inhibition of PAR-1 in TRAMP tumor cells by viral transduction with a construct containing an shRNA against murine PAR-1 in parallel to a non-specific shRNA construct. Diminishing tumor cell-associated PAR-1 expression resulted in significantly more rapid tumor growth in vivo. In order to better define the role of tumor cell-intrinsic PAR-1 we harvested TRAMP tumor cells from a PAR-1 deficient mouse and grew these cells in vitro. We transduced these PAR-1-deficient prostate tumor cells with viral vectors conferring expression of WT murine PAR-1 (PAR-1+), a PAR-1 mutant lacking the thrombin cleavage (R41A mutant) or empty vector (PAR-1-). PAR-1- cells grew robustly and similarly to the parental cells in vitro with a doubling time of approximately 48 hours. Cells expressing the R41A mutant PAR-1 also grew robustly and similarly to PAR-1 deficient cells. However, PAR-1+ cells failed to show any signs of cell proliferation over the span of a 4 day observation period. Furthermore, PAR-1 expression dramatically altered the ability of TRAMP cells to demonstrate signs of cell spreading as measured by the frequency of pseudopodia per cell. As a means of determining the role of PAR-1 in tumorigenesis and tumor growth in another spontaneously occurring setting, we interbred PAR-1-/- mice with APCMin/+ mice genetically predisposed to intestinal adenoma formation due to loss of heterozygosity of the tumor suppressor adenomatous polyposis coli gene. Blinded quantitative histological analyses of the intestinal tracts of PAR-1-/- and PAR-1+/+ APCMin/+ mice revealed that PAR-1 deficiency resulted in a significant 2-fold increase in the number of adenomas observed. Furthermore, the adenomas observed in PAR-1-/- mice were significantly larger based on morphometric analyses of adenoma surface area in histological sections. In sum, these data demonstrate a surprising and unexpected role for PAR-1 in the inhibition of tumor growth in the context of two distinct tumor types. Disclosures No relevant conflicts of interest to declare.

scholarly journals Tumor cell heterogeneity in multiple myeloma: antigenic, morphologic, and functional studies of cells from blood and bone marrow

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1925-1935
Author(s):  
MA King ◽  
DS Nelson
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Tumor Cell ◽  
Tumor Cells ◽  
B Lymphocytes ◽  
Plasma Cells ◽  
Bone Marrow Cells ◽  
Cell Types ◽  
Pokeweed Mitogen

Tumor cells from six patients with immunoglobulin G (IgG) multiple myeloma were analyzed for surface antigens, cytoplasmic paraprotein, morphology, and response to various culture conditions. The tumor marker was the paraprotein idiotype. Low numbers of tumor cells were found in the blood of most of the patients. In some patients, the circulating tumor cells were solely B lymphocytes, whereas in other patients, they were lymphoid, lymphoplasmacytoid, and plasmacytoid. Dual surface antigen analysis of blood and bone marrow cells confirmed that the tumor may be composed of a spectrum of cell types. Thus, cells may range from surface-idiotype+,CD19+,CD20+, PCA-1-,cytoplasmic- idiotype- lymphocytes, to CD19-,PCA-1+,cytoplasmic-idiotype+ plasma cells that are surface-idiotype- or weakly surface-idiotype+. In one patient, some of the tumor cells co-expressed surface idiotype and CD10. The tumor B lymphocytes were activated in vitro to synthesize paraprotein by pokeweed mitogen (PWM), and by low molecular weight B cell growth factor (BCGF). In contrast, spontaneous synthesis of paraprotein by more mature tumor cells was inhibited by agents that also inhibit nonmyeloma plasma cells. These agents included PWM, gamma interferon, and phorbol ester. The results demonstrate that in multiple myeloma there exist different tumor cell types that are similar, by a variety of criteria, to normal B lineage cells at different stages of differentiation. Thus, further evidence is provided for the hypothesis of myeloma cell differentiation.

scholarly journals Tumor cell heterogeneity in multiple myeloma: antigenic, morphologic, and functional studies of cells from blood and bone marrow

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1925-1935 ◽  
Author(s):  
MA King ◽  
DS Nelson
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Tumor Cell ◽  
Tumor Cells ◽  
B Lymphocytes ◽  
Plasma Cells ◽  
Bone Marrow Cells ◽  
Cell Types ◽  
Pokeweed Mitogen

Abstract Tumor cells from six patients with immunoglobulin G (IgG) multiple myeloma were analyzed for surface antigens, cytoplasmic paraprotein, morphology, and response to various culture conditions. The tumor marker was the paraprotein idiotype. Low numbers of tumor cells were found in the blood of most of the patients. In some patients, the circulating tumor cells were solely B lymphocytes, whereas in other patients, they were lymphoid, lymphoplasmacytoid, and plasmacytoid. Dual surface antigen analysis of blood and bone marrow cells confirmed that the tumor may be composed of a spectrum of cell types. Thus, cells may range from surface-idiotype+,CD19+,CD20+, PCA-1-,cytoplasmic- idiotype- lymphocytes, to CD19-,PCA-1+,cytoplasmic-idiotype+ plasma cells that are surface-idiotype- or weakly surface-idiotype+. In one patient, some of the tumor cells co-expressed surface idiotype and CD10. The tumor B lymphocytes were activated in vitro to synthesize paraprotein by pokeweed mitogen (PWM), and by low molecular weight B cell growth factor (BCGF). In contrast, spontaneous synthesis of paraprotein by more mature tumor cells was inhibited by agents that also inhibit nonmyeloma plasma cells. These agents included PWM, gamma interferon, and phorbol ester. The results demonstrate that in multiple myeloma there exist different tumor cell types that are similar, by a variety of criteria, to normal B lineage cells at different stages of differentiation. Thus, further evidence is provided for the hypothesis of myeloma cell differentiation.

Sign in / Sign up

Export Citation Format

Share Document