scholarly journals AKT-mediated phosphorylation of Sox9 induces Sox10 transcription in a murine model of HER2-positive breast cancer.

2020 ◽  
Author(s):  
Khalid N. Al-Zahrani ◽  
John Abou-Hamad ◽  
Cedrik Labreche ◽  
Brennan Garland ◽  
Luc Sabourin
Keyword(s):  
Tumor Cells ◽  
Mammary Tumor ◽  
Regulatory Region ◽  
Tumor Model ◽  
Binding Activity ◽  
Breast Cancers ◽  
Her2 Positive ◽  
Sox10 Expression

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.

scholarly journals AKT-mediated phosphorylation of Sox9 induces Sox10 transcription in a murine model of HER2-positive breast cancer

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Khalid N. Al-Zahrani ◽  
John Abou-Hamad ◽  
Julia Pascoal ◽  
Cédrik Labrèche ◽  
Brennan Garland ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Mammary Tumor ◽  
Regulatory Region ◽  
Tumor Model ◽  
Binding Activity ◽  
Breast Cancers ◽  
Her2 Positive ◽  
Sox10 Expression

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.

scholarly journals O80: GREMLIN-1 PROMOTES TUMOURIGENESIS AND METASTASIS IN HER2 POSITIVE BREAST CANCER

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
C Zabkiewicz ◽  
L Ye ◽  
R Hargest
Keyword(s):  
Breast Cancer ◽  
Cellular Growth ◽  
Breast Cancers ◽  
Her2 Positive ◽  
Mesenchymal Transition ◽  
Her2 Breast Cancer ◽  
Bmp Signalling ◽  
Gremlin 1

Abstract Introduction HER2 over-expression denotes poor prognosis in breast cancers.Bone morphogenetic protein(BMP) signalling is known to interact with EGF signalling, co-regulating breast cancer progression.BMP antagonist Gremlin-1 may influence breast cancer disease progression, but this remains unexplored in HER2 positive breast cancers. Method GREM1 and HER2 expression, and clinical outcomes were examined in clinical cohorts.GREM1 overexpression or pEF control plasmid were transduced into BT474 HER2+breast cancer cells. In vitro function tests using BT474 pEF and BT474GREM1cells include 2D/3D growth, migration, and expression of epithelial to mesenchymal transition(EMT)markers. Signalling cascades were examined in BT474 treated with RhGremlin-1. In vivo, BALB/c nude mice underwent either mammary injection or intra-cardiac injection of BT474pEF or BT474GREM1 cells and disease burden assessed. Result GREM1 expression correlates with HER2 in breast tumours(p=0.03) and is higher in metastatic HER2 positive cancers (p = 0.04). HER2 positive patients with high GREM1 have poor survival(p = 0.0002). BT474GREM1cells have up-regulated markers of EMT compared to control. BT474 RhGremlin-1 treated cells have active AKT pathway signalling, independent of BMP signalling. In vitro,  BT474GREM1cells significantly proliferate and migrate compared to control(p<0.05 and p < 0.001).This is confirmed in vivo,  BT474GREM1 mice grew significantly larger mammary tumours(p<0.05) and had more PETCT metastatic hotspots. Conclusion Gremlin-1 is correlated with poor outcomes in HER2 patients and promotes breast cancer cellular growth, migration and metastasis.Gremlin-1 is a novel area of research with potential as a prognostic biomarker and therapeutic target for personalised, effective, breast cancer outcomes. Take-home message BMP antagonists are gaining interest for their potential in breast cancer prognosis and therapeutics.This novel area of research shows BMP antagonist Gremlin-1 is of importance in HER2 positive breast cancers. DRAGONS DEN

Monoclonal antibody 2C5-mediated binding of liposomes to brain tumor cells in vitro and in subcutaneous tumor model in vivo

2005 ◽  
Vol 13 (6) ◽  
pp. 337-343 ◽  
Author(s):  
Bhawna Gupta ◽  
Tatiana S. Levchenko ◽  
Dmitry A. Mongayt ◽  
Vladimir P. Torchilin
Keyword(s):  
Monoclonal Antibody ◽  
Brain Tumor ◽  
Tumor Cells ◽  
Tumor Model ◽  
Subcutaneous Tumor ◽  
Brain Tumor Cells

scholarly journals Breast Tumor Cells Highly Resistant to Drugs Are Controlled Only by the Immune Response Induced in an Immunocompetent Mouse Model

2019 ◽  
Vol 18 ◽  
pp. 153473541984804 ◽  
Author(s):  
Paola Lasso ◽  
Mónica Llano Murcia ◽  
Tito Alejandro Sandoval ◽  
Claudia Urueña ◽  
Alfonso Barreto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Immune Response ◽  
Tumor Cells ◽  
High Capacity ◽  
Cancer Cell Line ◽  
Tumor Model ◽  
Main Element ◽  
In Vivo Models

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.

In vitro and in vivo assessments of two novel hydrazide compounds against breast cancer as well as mammary tumor cells

2017 ◽  
Vol 79 (6) ◽  
pp. 1195-1203 ◽  
Author(s):  
Elham Mousavi ◽  
Shahrzad Tavakolfar ◽  
Ali Almasirad ◽  
Zahra Kooshafar ◽  
Soudeh Dehghani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Mammary Tumor ◽  
Mammary Tumor Cells

scholarly journals A comparison of HER2 tumor accumulations of Ga-67 labeled anti-HER2 antibody with chemically and site-specifically conjugated bifunctional chelators

2020 ◽  
Author(s):  
Yumiko Kono ◽  
Keita Utsunomiya ◽  
Yuta Ohira ◽  
Hirokazu Satoh ◽  
Naoki Kan ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Capacity ◽  
Binding Activity ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Studies ◽  
Her2 Positive ◽  
Site Specific ◽  
Planar Images

Abstract Background Monoclonal antibodies (mAb) developed to target specific cancers have achieved considerable success to-date. To further enhance therapeutic efficacy monoclonal antibodies may be conjugated with a cytotoxic drug or radioisotope. We present the development of new method based on site-specific conjugation (SSC) for targeting HER2. The study design involves a comparison of the accumulation of Ga-67 labeled anti-HER2 antibodies with SSC versus conventional chemical conjugation in HER2-positive tumors. Anti-HER2 antibodies were chemically conjugated (Chem) with the bifunctional chelator deferoxamine (Chem-mAb). The resulting chemical conjugate was radiolabeled with Ga-67 yielding Ga-67-Chem -mAb. The SSC anti-HER2 antibodies enzymatically conjugated with deferoxamine using transglutaminase (SSC-mAb) and radiolabeled with Ga-67 yielding Ga-67-SSC-mAb. In vitro, the binding activity of HER2 to both conjugated antibodies was measured using surface Plasmon resonance. In vivo, a xenograft mouse model consisting of transplanted CHO/HER2 were divided into two groups, the Chem and the SSC group. Planar images were acquired over three days after each mAb injection, respectively. Pharmacokinetic analysis was used to compare the Chem group to the SSC group, for Ga-67 accumulation. Result The SSC and Chem groups were found to have similar HER2 binding capacity, however the tumor accumulation ratio gradually increased in the SSC group. The pharmacokinetic studies also found that radiolabeled mAb accumulation was significantly higher in the SSC group than the Chem group in not only the tumors, but also in blood and in other organs. Conclusion The new site-specific conjugation may improve targeted antigen-specific cancer radioimmunotherapy and may, due to higher retention, require a lower dose.

scholarly journals Simultaneous Multi-Organ Metastases from Chemo-Resistant Triple-Negative Breast Cancer Are Prevented by Interfering with WNT-Signaling

Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2039 ◽  
Author(s):  
Iram Fatima ◽  
Ikbale El-Ayachi ◽  
Hilaire C. Playa ◽  
Jackelyn A. Alva-Ornelas ◽  
Aysha B. Khalid ◽  
...  
Keyword(s):  
Cell Lines ◽  
Triple Negative ◽  
De Novo ◽  
Tumor Model ◽  
Model Systems ◽  
Breast Cancers ◽  
Primary Tumors ◽  
Multiple Organs

Triple-negative breast cancers (TNBCs), which lack specific targeted therapy options, evolve into highly chemo-resistant tumors that metastasize to multiple organs simultaneously. We have previously shown that TNBCs maintain an activated WNT10B-driven network that drives metastasis. Pharmacologic inhibition by ICG-001 decreases β-catenin-mediated proliferation of multiple TNBC cell lines and TNBC patient-derived xenograft (PDX)-derived cell lines. In vitro, ICG-001 was effective in combination with the conventional cytotoxic chemotherapeutics, cisplatin and doxorubicin, to decrease the proliferation of MDA-MB-231 cells. In contrast, in TNBC PDX-derived cells doxorubicin plus ICG-001 was synergistic, while pairing with cisplatin was not as effective. Mechanistically, cytotoxicity induced by doxorubicin, but not cisplatin, with ICG-001 was associated with increased cleavage of PARP-1 in the PDX cells only. In vivo, MDA-MB-231 and TNBC PDX orthotopic primary tumors initiated de novo simultaneous multi-organ metastases, including bone metastases. WNT monotherapy blocked multi-organ metastases as measured by luciferase imaging and histology. The loss of expression of the WNT10B/β-catenin direct targets HMGA2, EZH2, AXIN2, MYC, PCNA, CCND1, transcriptionally active β-catenin, SNAIL and vimentin both in vitro and in vivo in the primary tumors mechanistically explains loss of multi-organ metastases. WNT monotherapy induced VEGFA expression in both tumor model systems, whereas increased CD31 was observed only in the MDA-MB-231 tumors. Moreover, WNT-inhibition sensitized the anticancer response of the TNBC PDX model to doxorubicin, preventing simultaneous metastases to the liver and ovaries, as well as to bone. Our data demonstrate that WNT-inhibition sensitizes TNBC to anthracyclines and treats multi-organ metastases of TNBC.

[10]-Gingerol Affects Multiple Metastatic Processes and Induces Apoptosis in MDAMB- 231 Breast Tumor Cells

2019 ◽  
Vol 19 (5) ◽  
pp. 645-654 ◽  
Author(s):  
Angelina M. Fuzer ◽  
Ana C.B.M. Martin ◽  
Amanda B. Becceneri ◽  
James A. da Silva ◽  
Paulo C. Vieira ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Antitumor Agents ◽  
Apoptotic Cell ◽  
3D Culture ◽  
Primary Concern ◽  
Breast Cancers ◽  
Her2 Gene

Background: Triple Negative Breast Cancer (TNBC) represents the approximately 15% of breast cancers that lack expression of Estrogen (ER) and Progesterone Receptors (PR) and do not exhibit amplification of the human epidermal growth factor receptor 2 (HER2) gene, imposing difficulties to treatment. Interactions between tumor cells and their microenvironment facilitate tumor cell invasion in the surrounding tissues, intravasation through newly formed vessels, and dissemination to form metastasis. To treat metastasis from breast and many other cancer types, chemotherapy is one of the most extensively used methods. However, its efficacy and safety remain a primary concern, as well as its toxicity and other side effects. Thus, there is increasing interest in natural antitumor agents. In a previous work, we have demonstrated that [10]-gingerol is able to revert malignant phenotype in breast cancer cells in 3D culture and, moreover, to inhibit the dissemination of TNBC to multiple organs including lung, bone and brain, in spontaneous and experimental in vivo metastasis assays in mouse model. Objective: This work aims to investigate the in vitro effects of [10]-gingerol, using human MDA-MB-231TNBC cells, in comparison to non-tumor MCF-10A breast cells, in order to understand the antitumor and antimetastatic effects found in vivo and in a 3D environment. Methods: We investigated different steps of the metastatic process in vitro, such as cell migration, invasion, adhesion and MMP activity. In addition, we analyzed the anti-apoptotic and genotoxic effects of [10]-gingerol using PEAnnexin, DNA fragmentation, TUNEL and comet assays, respectively. Results: [10]-gingerol was able to inhibit cell adhesion, migration, invasion and to induce apoptosis more effectively in TNBC cells, when compared to non-tumor cells, demonstrating that these mechanisms can be involved in the antitumor and antimetastatic effects of [10]-gingerol, found both in 3D culture and in vivo. Conclusion: Taken together, results found here are complementary to previous studies of our group and others and demonstrate that additional mechanisms, besides apoptotic cell death, is used by [10]-gingerol to accomplish its antitumor and antimetastatic effects. Our results indicate a potential for this natural compound as an antitumor molecule or as an adjuvant for chemotherapeutics already used in the clinic.

scholarly journals Leptin deficiency suppresses MMTV-Wnt-1 mammary tumor growth in obese mice and abrogates tumor initiating cell survival

2011 ◽  
Vol 18 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Qiao Zheng ◽  
Sarah M Dunlap ◽  
Jinling Zhu ◽  
Erinn Downs-Kelly ◽  
Jeremy Rich ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Tumor Cells ◽  
Mammary Tumor ◽  
Leptin Receptor ◽  
Tumor Burden ◽  
Obese Mice ◽  
Leptin Deficiency ◽  
Phosphorylated Akt

Obesity increases both the risk and mortality associated with many types of cancer including that of the breast. In mice, obesity increases both incidence of spontaneous tumors and burden of transplanted tumors. Our findings identify leptin, an adipose secreted cytokine, in promoting increased mammary tumor burden in obese mice and provide a link between this adipokine and cancer. Using a transplantable tumor that develops spontaneously in the murine mammary tumor virus-Wnt-1 transgenic mice, we show that tumors transplanted into obese leptin receptor (LepRb)-deficient (db/db) mice grow to eight times the volume of tumors transplanted into lean wild-type (WT) mice. However, tumor outgrowth and overall tumor burden is reduced in obese, leptin-deficient (ob/ob) mice. The residual tumors in ob/ob mice contain fewer undifferentiated tumor cells (keratin 6 immunopositive) compared with WT or db/db mice. Furthermore, tumors in ob/ob mice contain fewer cells expressing phosphorylated Akt, a growth promoting kinase activated by the LepRb, compared with WT and db/db mice.In vivolimiting dilution analysis of residual tumors from ob/ob mice indicated reduced tumor initiating activity suggesting fewer cancer stem cells (CSCs). The tumor cell populations reduced by leptin deficiency were identified by fluorescence-activated cell sorting and found to express LepRb. Finally, LepRb expressing tumor cells exhibit stem cell characteristics based on the ability to form tumorspheresin vitroand leptin promotes their survival. These studies provide critical new insight on the role of leptin in tumor growth and implicate LepRb as a CSC target.

scholarly journals The adenosine 2a receptor and TIM3 directly inhibit killing of tumor cells by cytotoxic T lymphocytes through interference with cytoskeletal polarization

2021 ◽  
Author(s):  
Grace L. Edmunds ◽  
Carissa W.L. Wong ◽  
Rachel Ambler ◽  
Emily Milodowski ◽  
Hanin Alamir ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Tumor Response ◽  
Ex Vivo ◽  
Cytotoxic T Cells ◽  
Tumor Model ◽  
Cell Type ◽  
Adenosine 2A Receptor ◽  
Tumor Cell Killing

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.

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