scholarly journals Inhibition of the receptor tyrosine kinase ROR1 by anti-ROR1 monoclonal antibodies and siRNA induced apoptosis of melanoma cells.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22198-e22198
Author(s):  
Mohammad Hojat Farsangi ◽  
Fatemeh Ghaemimanesh ◽  
Amir Hossein Daneshmanesh ◽  
Ali-Ahmad Bayat ◽  
Jafar Mahmoudian ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tyrosine Kinase ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Receptor Tyrosine Kinase ◽  
Melanoma Cells ◽  
Immune Effector ◽  
Effector Cells ◽  
Immune Effector Cells ◽  
Melanoma Cell Lines

e22198 Background: The receptor tyrosine kinase ROR1 has important functions during normal embryogenesis. It is overexpressed and of importance for the survival of different malignancies, including lung adenocarcinoma, breast cancer and chronic lymphocytic leukemia (CLL). ROR1 inhibition in CLL cells and cell lines with high expression of ROR1 induced specific apoptosis of the cells. There is however little information on the expression and function of ROR1 in melanoma. Here, we investigated ROR1 expression, phosphorylation and the effects of anti-ROR1 monoclonal antibodies (mAbs) and ROR1 suppressing siRNA on seven melanoma cell lines. Methods: ROR1 expression and phosphorylation was analysed in a series of malignant melanoma cell lines using RT-PCR, immunocytochemistry, flow cytometry and western blot. Annexin V/PI staining, MTT assay, PARP and caspase 8 and 9 cleavage as well as MCL-1 protein were used for detection of apoptosis induced by anti-ROR1 mAbs. The cytotoxic effects of anti-ROR1 mAbs were evaluated in the absence or presence of complement (CDC) or immune effector cells (ADCC). Transfection of melanoma cell lines using ROR1 siRNA was used for gene silencing. Results: ROR1 was shown to be overexpressed to a varying degree at protein level. ROR1 was phosphorylated at tyrosine and serine residues. Three out of four anti-ROR1 mAbs (clones 3H9, 5F1 and 1A8) induced a significant direct apoptosis of the ESTDAB049, ESTDAB112, DFW and A375 cell lines as well as cell death in the presence of complement or immune effector cells. ESTDAB081 and 094 cell lines were resistant to direct apoptosis of the four anti-ROR1 mAbs alone compared to the other melanoma cell lines, but not to complement dependent cytotoxicity (CDC) and antibody dependent cell mediated cytotoxicity (ADCC). ROR1 siRNA transfection induced down-regulation of the ROR1 expression both at the mRNA and protein levels proceeded by a significant apoptosis of the melanoma cells. Conclusions: The results indicate that ROR1 may play an important role in the survival of melanoma cells. The surface expression of ROR1 on melanoma cells may support the notion that ROR1 might be a suitable targeted for mAb therapy.

scholarly journals BRN2 and MITF together impact AXL expression in melanoma

2020 ◽  
Author(s):  
Jacinta L. Simmons ◽  
Hannah M. Neuendorf ◽  
Glen M. Boyle
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Tyrosine Kinase ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Receptor Tyrosine Kinase ◽  
Inverse Relationship ◽  
Therapy Resistance ◽  
Disease Relapse ◽  
Melanoma Cell Lines

AbstractThe inverse relationship between transcription factor MITF and receptor tyrosine kinase AXL has received much attention recently. It is thought that melanoma tumors showing AXLhigh/MITFlow levels are resistant to therapy. We show here that a population of cells within melanoma tumors with extremely high expression of AXL are negative/low for both MITF and the transcription factor BRN2. Depletion of both transcription factors from cultured melanoma cell lines produced an increase in AXL expression greater than depletion of MITF alone. Further, re-expression of BRN2 led to decreased AXL expression, indicating a role for BRN2 in regulation of AXL levels unrelated to effects on MITF level. As AXL has been recognized as a marker of therapy resistance these cells may represent a population of cells responsible for disease relapse and as potential targets for therapeutic treatment.

scholarly journals Synergy, Additivity, and Antagonism between Cisplatin and Selected Coumarins in Human Melanoma Cells

2021 ◽  
Vol 22 (2) ◽  
pp. 537
Author(s):  
Paula Wróblewska-Łuczka ◽  
Aneta Grabarska ◽  
Magdalena Florek-Łuszczki ◽  
Zbigniew Plewa ◽  
Jarogniew J. Łuszczki
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Type I ◽  
Antiproliferative Effects ◽  
Isobolographic Analysis ◽  
Natural Substances ◽  
Additive Interactions ◽  
Melanoma Cell Lines

(1) Cisplatin (CDDP) is used in melanoma chemotherapy, but it has many side effects. Hence, the search for natural substances that can reduce the dose of CDDP, and CDDP-related toxicity, is highly desired. Coumarins have many biological properties, including anticancer and antiproliferative effects. (2) An in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on two human melanoma cell lines (FM55P and FM55M2) examined the antitumor properties of CDDP and five naturally occurring coumarins (osthole, xanthotoxin, xanthotoxol, isopimpinellin, and imperatorin). The antiproliferative effects produced by combinations of CDDP with the coumarins were assessed using type I isobolographic analysis. (3) The most potent anticancer properties of coumarins were presented by osthole and xanthotoxol. These compounds were characterized by the lowest median inhibitory concentration (IC50) values relative to the FM55P and FM55M2 melanoma cells. Isobolographic analysis showed that for both melanoma cell lines, the combination of CDDP and osthole exerted synergistic and additive interactions, while the combination of CDDP and xanthotoxol exerted additive interactions. Combinations of CDDP with xanthotoxin, isopimpinellin, and imperatorin showed antagonistic and additive interactions in two melanoma cell lines. (4) The combination of CDDP and osthole was characterized by the most desirable synergistic interaction. Isobolographic analysis allows the selection of potential candidates for cancer drugs among natural substances.

scholarly journals Antibody-based therapy of leukaemia

2009 ◽  
Vol 11 ◽  
Author(s):  
John C. Morris ◽  
Thomas A. Waldmann
Keyword(s):  
Monoclonal Antibodies ◽  
T Cell ◽  
B Cell ◽  
Gemtuzumab Ozogamicin ◽  
Cell Leukaemia ◽  
Target Cells ◽  
Immune Effector ◽  
Effector Cells ◽  
Prolymphocytic Leukaemia ◽  
Immune Effector Cells

Over the past decade, monoclonal antibodies have dramatically impacted the treatment of haematological malignancies, as evidenced by the effect of rituximab on the response rate and survival of patients with follicular and diffuse large B cell non-Hodgkin's lymphoma. Currently, only two monoclonal antibodies – the anti-CD33 immunotoxin gemtuzumab ozogamicin and the CD52-directed antibody alemtuzumab – are approved for treatment of relapsed acute myeloid leukaemia in older patients and B cell chronic lymphocytic leukaemia, respectively. Although not approved for such treatment, alemtuzumab is also active against T cell prolymphocytic leukaemia, cutaneous T cell lymphoma and Sézary syndrome, and adult T cell leukaemia and lymphoma. In addition, rituximab has demonstrated activity against B cell chronic lymphocytic and hairy cell leukaemia. Monoclonal antibodies targeting CD4, CD19, CD20, CD22, CD23, CD25, CD45, CD66 and CD122 are now being studied in the clinic for the treatment of leukaemia. Here, we discuss how these new antibodies have been engineered to reduce immunogenicity and improve antibody targeting and binding. Improved interactions with Fc receptors on immune effector cells can enhance destruction of target cells through antibody-dependent cellular cytotoxicity and complement-mediated cell lysis. The antibodies can also be armed with cellular toxins or radionuclides to enhance the destruction of leukaemia cells.

Secretion of Cytokines by Human Choroidal Melanoma Cells and Skin Melanoma Cell Lines in vitro

1998 ◽  
Vol 30 (3) ◽  
pp. 189-194 ◽  
Author(s):  
Volker Enzmann ◽  
Frank Faude ◽  
Leon Kohen ◽  
Peter Wiedemann
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Choroidal Melanoma ◽  
Melanoma Cells ◽  
Skin Melanoma ◽  
Melanoma Cell Lines

scholarly journals Identification and characterization of a low-affinity granulocyte- macrophage colony-stimulating factor receptor on primary and cultured human melanoma cells

Blood ◽  
1991 ◽  
Vol 78 (3) ◽  
pp. 609-615 ◽  
Author(s):  
GC Baldwin ◽  
DW Golde ◽  
GF Widhopf ◽  
J Economou ◽  
JC Gasson
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor ◽  
Melanoma Cell Lines

Abstract Hematopoietic growth factor receptors are present on cells of normal nonhematopoietic tissues such as endothelium and placenta. We previously demonstrated functional human granulocyte-macrophage colony- stimulating factor (GM-CSF) receptors on small cell carcinoma of the lung cell lines, and others have reported that certain solid tumor cell lines respond to GM-CSF in clonogenic assays. In the current study, we examine human melanoma cell lines and fresh specimens of melanoma to determine whether they have functional GM-CSF receptors. Scatchard analyses of 125I-GM-CSF equilibrium binding to melanoma cell lines showed a mean of 542 +/- 67 sites per cell with a kd of 0.72 +/- 0.14 nmol/L. Cross-linking studies in the melanoma cell line, M14, showed a major GM-CSF receptor species of 84,000 daltons. Under the conditions tested, the M14 cells did not have a proliferative response to GM-CSF in vitro, nor was any induction of primary response genes detected by Northern analysis in response to GM-CSF. Studies to determine internal translocation of the receptor-ligand complex indicated less than 10% of the 125I-GM-CSF internalized was specifically bound to receptors. Primary melanoma cells from five surgical specimens had GM-CSF receptors; Scatchard analysis was performed on one sample, showing 555 sites/cell with a kd of 0.23 nmol/L. These results indicate that human tumor cells may express a low-affinity GM-CSF receptor protein that localizes to the cell surface and binds ligand, but lacks functional components or accessory factors needed to transduce a signal.

scholarly journals Enhancing antibody-dependent cell-mediated cytotoxicity: a strategy for improving antibody-based immunotherapy

2018 ◽  
Vol 1 (1) ◽  
pp. 7-12 ◽  
Author(s):  
David Zahavi ◽  
Dalal AlDeghaither ◽  
Allison O’Connell ◽  
Louis M Weiner
Keyword(s):  
Monoclonal Antibodies ◽  
Mechanism Of Action ◽  
Clinical Performance ◽  
Cancer Therapeutics ◽  
Surface Antigens ◽  
Immune Effector ◽  
Effector Cells ◽  
Immune Effector Cells ◽  
Dependent Cell ◽  
Antibody Design

ABSTRACT The targeting of surface antigens expressed on tumor cells by monoclonal antibodies (mAbs) has revolutionized cancer therapeutics. One mechanism of action of antibody-based immunotherapy is the activation of immune effector cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). This review will summarize the process of ADCC, its important role in the efficacy of mAb therapy, how to measure it, and finally future strategies for antibody design that can take advantage of it to improve clinical performance.

Effect of small inhibitors of nuclear export (SINE) on growth inhibition and apoptosis of human melanoma cells.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13549-e13549
Author(s):  
Gregory B. Lesinski ◽  
Jennifer Yang ◽  
Matthew A Bill ◽  
Yosef Landesman ◽  
Sharon Shacham ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Cell Lines ◽  
Melanoma Cell ◽  
Nuclear Export ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Human Melanoma Cell ◽  
Nuclear Accumulation ◽  
Dependent Manner ◽  
Melanoma Cell Lines

e13549 Background: Inhibition of nuclear export can promote re-activation of tumor suppressor pathways. CRM1 (chromosomal regional maintenance 1) or XPO1 (exportin 1) is the major protein that mediates nuclear export. We hypothesized that CRM1 mediated nuclear export represents a novel therapeutic target that can be manipulated to inhibit melanoma cell survival. Methods: The growth inhibitory and pro-apoptotic effects of KPT-185, KPT-276 and KPT-330, small molecules selective inhibitor of nuclear export (SINE) were evaluated in human melanoma cell lines using an MTT assay and Annexin V/PI staining, respectively. Fluorescence microscopy and immunoblots were used to assess nuclear accumulation of tumor suppressor proteins. The trans-isomer of KPT-185 and DMSO (vehicle) were used as a negative controls in all assays. The pharmacokinetic (PK) profile of all compounds was evaluated in mice. Results: CRM1 protein was highly expressed in human melanoma cell lines with diverse molecular profiles (i.e., B-Raf, NRAS, p53). KPT-SINE inhibited melanoma cell growth in a concentration-dependent manner and induced apoptosis at nanomolar concentrations. Importantly, there was no evidence that B-Raf V600 mutational status influenced melanoma cell response to these agents. Nuclear accumulation and/or induction of p53, p21, FOXO3a, STAT1 and BAD, and reduction of MCL-1 occurred in melanoma cells at time points prior to apoptosis as shown by increase in cleaved PARP and caspase 3 levels. PK studies were conducted in mice following oral administration of 10 mg/kg, to guide drug selection for our ongoing efficacy studies in murine melanoma models. KPT-185 showed limited bioavailability and systemic exposure, while KPT-276 and KPT-330 showed >50% bioavailability reaching Cmax >5µM. Conclusions: This study represents the first report of CRM1 inhibition in melanoma. These data indicate that the novel SINE compounds can effectively inhibit CRM1-mediated nuclear export and induce apoptosis in melanoma cells. KPT-330 is currently under development as orally bioavailable, small molecule inhibitors for a human clinical trial.

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