The relationship between the in vitro chemosensitivity of tumor cells and tumor response in vivo in an experimental tumor model

1991 ◽  
Vol 9 (2) ◽  
pp. 144-154 ◽  
Author(s):  
R. M. Phillips ◽  
M. C. Bibby ◽  
J. A. Double ◽  
P. M. Loadman
2021 ◽  
Author(s):  
Grace L. Edmunds ◽  
Carissa W.L. Wong ◽  
Rachel Ambler ◽  
Emily Milodowski ◽  
Hanin Alamir ◽  
...  

Tumors generate an immune-suppressive environment that prevents effective killing of tumor cells by CD8+ cytotoxic T cells (CTL). It remains largely unclear upon which cell type and at which stage of the anti-tumor response mediators of suppression act. We have combined an in vivo tumor model with a matching in vitro reconstruction of the tumor microenvironment based on tumor spheroids to identify suppressors of anti-tumor immunity that directly act on interaction between CTL and tumor cells and to determine mechanisms of action. An adenosine 2a receptor antagonist, as enhanced by blockade of TIM3, slowed tumor growth in vivo. Engagement of the adenosine 2a receptor and TIM3 reduced tumor cell killing in spheroids, impaired CTL cytoskeletal polarization ex vivo and in vitro and inhibited CTL infiltration into tumors and spheroids. With this focus on CTL killing, blocking A2aR and TIM3 complements therapies that enhance T cell priming, e.g. anti-PD1 and anti-CTLA-4.


2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Grace L. Edmunds ◽  
Carissa C. W. Wong ◽  
Rachel Ambler ◽  
Emily J. Milodowski ◽  
Hanin Alamir ◽  
...  

AbstractTumors generate an immune-suppressive environment that prevents effective killing of tumor cells by CD8+ cytotoxic T cells (CTL). It remains largely unclear upon which cell type and at which stage of the anti-tumor response mediators of suppression act. We have combined an in vivo tumor model with a matching in vitro reconstruction of the tumor microenvironment based on tumor spheroids to identify suppressors of anti-tumor immunity that directly act on interaction between CTL and tumor cells and to determine mechanisms of action. An adenosine 2A receptor antagonist, as enhanced by blockade of TIM3, slowed tumor growth in vivo. Engagement of the adenosine 2A receptor and TIM3 reduced tumor cell killing in spheroids, impaired CTL cytoskeletal polarization ex vivo and in vitro and inhibited CTL infiltration into tumors and spheroids. With this role in CTL killing, blocking A2AR and TIM3 may complement therapies that enhance T cell priming, e.g. anti-PD-1 and anti-CTLA-4.


2005 ◽  
Vol 13 (6) ◽  
pp. 337-343 ◽  
Author(s):  
Bhawna Gupta ◽  
Tatiana S. Levchenko ◽  
Dmitry A. Mongayt ◽  
Vladimir P. Torchilin

2019 ◽  
Vol 18 ◽  
pp. 153473541984804 ◽  
Author(s):  
Paola Lasso ◽  
Mónica Llano Murcia ◽  
Tito Alejandro Sandoval ◽  
Claudia Urueña ◽  
Alfonso Barreto ◽  
...  

Background: The tumor cells responsible for metastasis are highly resistant to chemotherapy and have characteristics of stem cells, with a high capacity for self-regeneration and the use of detoxifying mechanisms that participate in drug resistance. In vivo models of highly resistant cells allow us to evaluate the real impact of the immune response in the control of cancer. Materials and Methods: A tumor population derived from the 4T1 breast cancer cell line that was stable in vitro and highly aggressive in vivo was obtained, characterized, and determined to exhibit cancer stem cell (CSC) phenotypes (CD44+, CD24+, ALDH+, Oct4+, Nanog+, Sox2+, and high self-renewal capacity). Orthotopic transplantation of these cells allowed us to evaluate their in vivo susceptibility to chemo and immune responses induced after vaccination. Results: The immune response induced after vaccination with tumor cells treated with doxorubicin decreased the formation of tumors and macrometastasis in this model, which allowed us to confirm the immune response relevance in the control of highly chemotherapy-resistant ALDH+ CSCs in an aggressive tumor model in immunocompetent animals. Conclusions: The antitumor immune response was the main element capable of controlling tumor progression as well as metastasis in a highly chemotherapy-resistant aggressive breast cancer model.


2020 ◽  
Author(s):  
Khalid N. Al-Zahrani ◽  
John Abou-Hamad ◽  
Cedrik Labreche ◽  
Brennan Garland ◽  
Luc Sabourin

Abstract Background: Approximately 5-10% of HER2-positive breast cancers can be defined by low expression of the Ste20-like kinase, SLK, and high expression of SOX10. Our lab has observed that genetic deletion of SLK results in the induction of Sox10 and significantly accelerates tumor initiation in a HER2-induced mammary tumor model. However, the mechanism responsible for the induction of SOX10 gene expression in this context remains unknown.Methods: Using tumor derived cell lines from MMTV-Neu mice lacking SLK and biochemical approaches, we have characterized the signaling mechanisms and relevant DNA elements driving Sox10 expression. Results: Biochemical and genetic analyses of the SOX10 regulatory region in SLK-deficient mammary tumor cells show that Sox10 expression is dependent on a novel -7kb enhancer that harbors three SoxE binding sites. ChIP analyses demonstrate that Sox9 is bound to those elements in vivo. Our data show that AKT can directly phosphorylate Sox9 in vitro at serine 181 and that AKT inhibition blocks Sox9 phosphorylation and Sox10 expression in SLK(-/-) tumor cells. AKT-mediated Sox9 phosphorylation increases its transcriptional activity on the Sox10 -7kb enhancer without altering its DNA binding activity. Interestingly, analysis of murine and human mammary tumors reveals a direct correlation between the levels of active phospho-Sox9 S181 and Sox10 expression.Conclusions: Our results have identified a novel Sox10 enhancer and validated Sox9 as direct target for AKT. As Sox10 is a biomarker for triple negative breast cancers (TNBC), these findings might have major implications in the targeting and treatment of those cancers.


2021 ◽  
Vol 14 (6) ◽  
pp. 521
Author(s):  
Nehal Gupta ◽  
Sanjay K. Srivastava

Triple-negative breast cancer (TNBC) is considered to be the most aggressive and malignant neoplasm and is highly metastatic in nature. In the current study, we investigated the anti-metastatic potential of atovaquone, a protozoal drug prescribed for Pneumocystis pneumonia. We showed that atovaquone induced apoptosis and reduced the survival of several aggressive metastatic TNBC cell lines including metastatic patient-derived cells by reducing the expression of integrin α6, integrin β4, FAK, Src, and Vimentin. In order to study the efficacy of atovaquone in suppressing metastasized breast tumor cells in brain and lungs, we performed three in vivo experiments. We demonstrated that oral administration of 50 mg/kg of atovaquone suppressed MDA-MB-231 breast tumor growth by 90% in lungs in an intravenous metastatic tumor model. Anti-metastatic effect of atovaquone was further determined by intracardiac injection of 4T1-luc breast tumor cells into the left ventricle of mouse heart. Our results showed that atovaquone treatment suppressed the growth of metastatic tumors in lungs, liver and brain by 70%, 50% and 30% respectively. In an intracranial model, the growth of HCC1806-luc brain tumors in atovaquone treated mice was about 55% less than that of control. Taken together, our results indicate the anti-metastatic effects of atovaquone in vitro and in vivo in various breast tumor metastasis models.


2021 ◽  
Vol 9 (10) ◽  
pp. e003468
Author(s):  
Huicheng Liu ◽  
Lili Bai ◽  
Liu Huang ◽  
Na Ning ◽  
Lin Li ◽  
...  

BackgroundTriple negative breast cancer (TNBC) is a subtype of breast cancers with poor prognosis and targeted drug therapies are limited. To develop novel and efficacious therapies for TNBC, we developed a bispecific antibody F7AK3 that recognizes both trophoblast cell surface antigen 2 (TROP2) and CD3 and evaluated its antitumor activities both in vitro and in vivo.MethodsThe binding affinities of F7AK3 to the two targets, TROP2 and CD3, were evaluated by surface plasmon resonance. Binding of F7AK3 to TNBC cells and T cells were evaluated by flow cytometry. Immunofluorescent staining was performed to demonstrate the interactions between T cells with TNBC cells. The cytotoxicity of T cells against TNBC cell lines and primary tumor cells mediated by F7AK3 were determined in vitro. In vivo antitumor activity of F7AK3 was investigated in a xenograft TNBC tumor model, using immunodeficient mice that were reconstituted with human peripheral blood mononuclear cells.ResultsWe demonstrated that F7AK3 binds specifically to human TROP2 and CD3 antigens, as well as TNBC cell lines and primary tumor cells. Human T cells can only be activated by F7AK3 in the presence of target tumor cells. F7AK3 recruits T cells to TROP2+ tumor cells in vitro and into tumor tissues in vivo. Antitumor growth activity of F7AK3 is observed in a xenograft TNBC tumor model.ConclusionThis study showed the antitumor potential of an anti-TROP2xCD3 bispecific antibody F7AK3 to TNBC tumor cells both in vitro and in vivo. These data demonstrate that F7AK3 has the potential to treat TNBC patients, which warrants further preclinical and clinical evaluation of the F7AK3 in advanced or metastatic TNBC patients.


2021 ◽  
Vol 20 ◽  
pp. 153473542110603
Author(s):  
Mai H. Mekkawy ◽  
Hanan A. Fahmy ◽  
Ahmed S. Nada ◽  
Ola S. Ali

Recent reports have shown that bromelain (BL), a pineapple extract, acts as an adjuvant therapy in cancer treatment and prevention of carcinogenesis. The present study was designed to investigate the possible mechanisms by which BL could radiosensitize tumor cells in vitro and in a mouse tumor model. BL has shown a significant reduction in the viability of the radioresistant human breast carcinoma (MCF-7) cell line using cell proliferation assay. The in vivo study was designed using the Ehrlich model in female albino mice, treated with BL (6 mg/kg b. wt., intraperitoneal, once daily for 10 days) 1 hour before exposure to a fractionated dose of gamma radiation (5 Gy, 1 Gy for 5 subsequent days). The radiosensitizing effect of BL was evident in terms of a significant reduction in tumor volume, poly ADP ribose polymerase-1 (PARP-1), the proliferation marker Ki-67 and nuclear factor kappa activated B cells (NF-κB) with a significant elevation in the reactive oxygen species (ROS) content and lipid peroxidation (LPO) in tumor cells. The present findings offer a novel insight into the radiosensitizing effect of BL and its potential application in the radiotherapy course.


2021 ◽  
Author(s):  
Viveka Nand Yadav ◽  
Micah K. Harris ◽  
Dana Messinger ◽  
Chase Thomas ◽  
Jessica R. Cummings ◽  
...  

Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumor with rare survival beyond two years. This poor prognosis is largely due to the tumor's highly infiltrative and invasive nature. Previous reports demonstrate upregulation of the transcription factor ID1 with H3K27M and ACVR1 mutations, but this has not been confirmed in human tumors or therapeutically targeted. We developed an in utero electroporation (IUE) murine H3K27M-driven tumor model, which demonstrates increased ID1 expression in H3K27M- and ACVR1-mutated tumor cells. In human tumors, elevated ID1 expression is associated with H3K27M/ACVR1-mutation, brainstem location, and reduced survival. The ID1 promoter demonstrates a similar active epigenetic state in H3K27M tumor cells and murine prenatal hindbrain cells. In the developing human brain, ID1 is expressed highest in oligo/astrocyte-precursor cells (OAPCs). These ID1+/SPARCL1+ cells share a transcriptional program with astrocyte-like (AC-like) DIPG cells, and demonstrate upregulation of gene sets involved with regulation of cell migration. Both genetic and pharmacologic [cannabidiol (CBD)] suppression of ID1 results in decreased DIPG cell invasion/migration in vitro and invasion/tumor growth in multiple in vivo models. CBD reduces proliferation through reactive oxygen species (ROS) production at low micromolar concentrations, which we found to be achievable in the murine brainstem. Further, pediatric high-grade glioma patients treated off-trial with CBD (n=15) demonstrate tumor ID1 reduction and improved overall survival compared to historical controls. Our study identifies that ID1 is upregulated in DIPG through reactivation of a developmental OAPC transcriptional state, and ID1-driven invasiveness of DIPG is therapeutically targetable with CBD.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Khalid N. Al-Zahrani ◽  
John Abou-Hamad ◽  
Julia Pascoal ◽  
Cédrik Labrèche ◽  
Brennan Garland ◽  
...  

Abstract Background Approximately 5–10% of HER2-positive breast cancers can be defined by low expression of the Ste20-like kinase, SLK, and high expression of SOX10. Our lab has observed that genetic deletion of SLK results in the induction of Sox10 and significantly accelerates tumor initiation in a HER2-induced mammary tumor model. However, the mechanism responsible for the induction of SOX10 gene expression in this context remains unknown. Methods Using tumor-derived cell lines from MMTV-Neu mice lacking SLK and biochemical approaches, we have characterized the signaling mechanisms and relevant DNA elements driving Sox10 expression. Results Biochemical and genetic analyses of the SOX10 regulatory region in SLK-deficient mammary tumor cells show that Sox10 expression is dependent on a novel −7kb enhancer that harbors three SoxE binding sites. ChIP analyses demonstrate that Sox9 is bound to those elements in vivo. Our data show that AKT can directly phosphorylate Sox9 in vitro at serine 181 and that AKT inhibition blocks Sox9 phosphorylation and Sox10 expression in SLK(-/-) tumor cells. AKT-mediated Sox9 phosphorylation increases its transcriptional activity on the Sox10 −7kb enhancer without altering its DNA-binding activity. Interestingly, analysis of murine and human mammary tumors reveals a direct correlation between the levels of active phospho-Sox9 S181 and Sox10 expression. Conclusions Our results have identified a novel Sox10 enhancer and validated Sox9 as a direct target for AKT. As Sox10 is a biomarker for triple-negative breast cancers (TNBC), these findings might have major implications in the targeting and treatment of those cancers.


Sign in / Sign up

Export Citation Format

Share Document