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- Djerf, Emelie, et al.
(author)
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ErbB receptor tyrosine kinases contribute to proliferation of malignant melanoma cells : inhibition by gefitinib (ZD1839)
- 2009
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In: Melanoma research. - 0960-8931 .- 1473-5636. ; 19:3, s. 156-166
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Journal article (peer-reviewed)abstract
- Members of the epidermal growth factor (EGF) family of structurally related tyrosine kinase receptors, known as the ErbB receptors (EGFR/ErbB1/HER1, ErbB2/HER2/neu, ErbB3/HER3 and ErbB4/HER4) and their respective ligands, have been suggested to be involved in the development and progression of malignant melanoma. Here we investigate the effects of the ErbB1 tyrosine kinase inhibitor gefitinib (ZD1839, Iressa) on human malignant melanoma cells (RaH3 and RaH5) in vitro. ZD1839 inhibited proliferation of exponentially growing RaH3 and RaH5 cells in a dose-dependent manner with a half-maximally effective dose of 3.5 and 2.0 mu mol/l, respectively. Cell growth was inhibited at 0.1 mu mol/l ZD1839 in both cell lines. Maximal inhibition was accomplished at 10 mu mol/l ZD1839; however, the effect was not complete as both cell lines showed a continuous slow growth during the treatment period. Flow cytometry analysis of cell-cycle distribution showed that ZD1839 treatment caused accumulation of RaH3 and RaH5 cells in the G, phase. The growth arrest induced by ZD1839 coincided with upregulation of the cyclin-dependent kinase inhibitor p27(KIP1). There was no increase in apoptosis as determined by analysis of plasma phosphatidyl serine redistribution. Western blot analysis revealed that ZD1839 substantially reduced tyrosine phosphorylation of ErbB1 as well as ErbB2 and ErbB3. This was accompanied by a concomitant decrease in Akt-phosphorylation, Erk1/2-phosphorylation, and Stat3-phosphorylation. Our results show that ZD1839 interferes with the growth of human malignant melanoma cells by cytostatic effects. These findings indicate the possible use of ErbB receptor kinase inhibitors as a novel treatment strategy in malignant melanoma.
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| 2. |
- Djerf, Emelie, 1980-
(author)
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Studies on the effect of ErbB tyrosine kinase inhibitors on malignant melanoma growth and survival in vitro
- 2009
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Licentiate thesis (other academic/artistic)abstract
- Malignant melanoma has one of the fastest increasing incidences among the different types of cancerin the Western world. This raise can partly be ascribed to the change in sun habits that has takenplace during the last decades, since the major external risk factor for melanoma is exposure toultraviolet radiation. Patients with early stages of melanoma can often be cured by surgery, howeverfor patients suffering from metastatic melanoma there are only a few treatment options available.Unfortunately malignant melanoma is often resistant to radio-, bio- and chemotherapy and treatmentwith the currently most frequently used agent, dacarbazine, is characterized by a very low clinicalresponse rate. Therefore, there is an urgent need for new treatment strategies which can increase theoverall survival and cause less severe side effects.The aim of this thesis was to investigate the anti-tumor effect of two different tyrosine kinaseinhibitors (TKIs), gefitinib and canertinib, on two different human malignant melanoma (RaH3 andRaH5) cell lines. We investigate the effect of these two drugs on cell proliferation and survival andstudied the effect of gefitinib and canertinib on ErbB1-4 receptor phosphorylation, as well as Akt,Erk1/2 and Stat3 activity.Our results showed that phosphorylation of ErbB1, ErbB2 and ErbB3 decreased followingtreatment with both gefitinib and canertinib and that the subsequent downstream signaling via Akt,Erk1/2 and Stat3 was inhibited after TKI treatment. However, it was noted that the gefitinibinducedinhibition of Akt, and particularly Erk1/2, was transient and only a weak inhibition of Stat3phosphorylation was seen. Gefitinib treatment of the RaH3 and RaH5 cells resulted in anaccumulation of the cells in the G1 phase of the cell cycle without any induction of apoptosis.Canertinib caused a more pronounced inhibition of Akt, Erk1/2, and Stat3 phosphorylation thangefitinib. This might be one explanation to why canertinib induced apoptosis in RaH3 and RaH5cells whereas gefitinib only caused cell cycle arrest. In conclusion, gefitinib and canertinib displaypromising anti-tumor effects on ErbB expressing malignant melanoma and might be used in futurestudies in combination with conventional chemotherapy or other targeted therapies in the treatmentof malignant melanoma.
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| 3. |
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| 4. |
- Hallbeck, Anna-Lotta, 1967-
(author)
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Studies of transforming growth factor alpha in normal and abnormal growth
- 2007
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Doctoral thesis (other academic/artistic)abstract
- Regulation of growth is of fundamental importance for development of the organism and to maintain health. The induction of cell proliferation and matrix production are influenced by several different signaling systems, most importantly by growth factors.The human HER-family of growth factor ligands and receptors is one of the most studied and, at present, one of the most complex including 4 tyrosine kinase receptors and at least 11 different ligands cooperating in the transfer of signals. The HER-family growth responses are also influenced by other intercellular and extracellular signals, including matrix components, cytokines and hormones mediating e.g. inflammation.HER-1 (EGFR) is one of the best known and most extensively studied growth factor receptors. TGF-alpha is possibly the most potent HER-1 ligand and influences wound healing, epidermal maintenance, gastrointestinal function, lactation, pulmonary function and more. Several studies have shown important regulatory functions for some inflammatory cytokines on TGF-alpha production in white blood cells. HER-1 is widespread in epithelial cells but also in mesenchymal cells such as fibroblasts, osteogenic and chondrogenic cells. Consequently, many tumors arising from these cell types express HER family members and often show TGF-alpha and/or HER activation. Indeed, mammary cancer development has been shown when over expressing both TGF-alpha and HER-2 in mouse mammary cells in vivo.In recent years the first HER-1 and HER-2 inhibitors have come into clinical practice for treatment of breast cancer, lung cancer and gastrointestinal cancers, sometimes with great success. However, more knowledge is needed concerning the inflammatory regulation of HER-family expression including where and how the ligands and receptors cooperate. Therefore we were interested in studying the role of TGF-alpha in normal and abnormal growth.First we showed that the acute inflammatory cytokine IL-6 regulates TGF-alpha expression in U-937-1 monocytoid cells. Secondly, we detected a possible long-term enhancing influence of singledose UVR on HER-1 expression in normal human melanocytes. We continued thirdly by revealing TGF-alpha production concomitant with HER-2 in normal human synovia and release of soluble TGF-alpha into the synovial fluid. Both TGF-alpha and HER-2 production were significantly increased in inflammatory joint conditions, e.g. RA. Fourthly, we demonstrated expression of TGF-alpha, HER-1 and HER-2 in synovial sarcoma cells in culture; the observed HER-2 phosphorylation was dependent on ligand induced HER-1 activation.The presented results indicate that TGF-alpha expression can be enhanced by acute inflammatory cytokine IL-6, possibly contributing to growth stimulatory effects assigned to IL-6 itself.The acute effects of UVR on melanocytes mediate up-regulated steady-state expression of HER-1, constituting a potential target for locally produced TGF-alpha that may induce melanocyte proliferation.TGF-alpha and HER-2 seem to have a role in the maintenance ofsynovial joint tissues. Upregulation of TGF-alpha and HER-2 in inflammatory joint conditions, e.g. RA, represents a novel mechanism for synovial proliferation contributing to joint deterioration.TGF-alpha, HER1 and HER-2 may have a role in synovial sarcoma proliferation; further investigation is needed to evaluate HER-family inhibitors as a possible treatment alternative in this type of cancer.
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| 5. |
- Hallbeck, Anna-Lotta, et al.
(author)
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TGF-alpha and ErbB2 production in synovial joint tissue: increased expression in arthritic joints
- 2005
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In: Scandinavian Journal of Rheumatology. - : Informa UK Limited. - 0300-9742 .- 1502-7732. ; 34:3, s. 204-211
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Journal article (peer-reviewed)abstract
- Objective: Cell types present in synovial joint tissues and during synovitis are known to produce epidermal growth factor receptor (EGFR)/ErbB-1/HER-1 and the potent EGFR-ligand transforming growth factor-alpha (TGF-) in vitro. Concomitant expression of TGF-, EGFR, and ErbB2 gives a strong proliferative drive in vitro and in vivo. However, the presence of TGF- and members of the EGFR/EGFR-ligand family has not been thoroughly investigated in joint tissue in vivo. We aimed to determine whether TGF-, EGFR, and ErbB2 are present in human synovial joints, especially during rheumatoid arthritis (RA). Methods: TGF- protein was immunodetected in knee synovial fluid (SF) collected from 23 RA patients, eight patients with other arthritic conditions, two osteoarthritis (OA) patients, and six post-traumatic patients (control). TGF- mRNA and TGF-, ErbB2, EGFR, and CD68 immunoreactivity were detected in knee synovial biopsies (6 RA/2 OA/6 control) using in situ hybridization and immunohistochemistry. TGF- mRNA was determined in SF cells by reverse transcription polymerase chain reaction (RT-PCR) and/or the Northern blot technique. Results: TGF- protein was found in the synovial membrane (SM) and in the majority of SF samples. TGF- levels were significantly higher (p<0.001) in SF of RA patients than controls, TGF- protein and mRNA were increased and more widespread in SM of RA patients. In addition, white blood cells collected from RA SF expressed TGF- mRNA. Immunoreactivity for ErbB2 was found in SM and was more widespread in RA patients than in controls. Conclusion: The presence of TGF- in normal SF and SM may indicate a physiological maintenance function. The increased expression of TGF- and ErbB2 in RA SF and SM may give rise to an abnormal growth pattern, contributing to inflammatory synovial hyperplasia.
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| 7. |
- Walz, Anke, et al.
(author)
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Identification of glycoprotein receptors within the human salivary proteome for the lectin-like BabA and SabA adhesins of Helicobacter pylori by fluorescence-based 2-D bacterial overlay
- 2009
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In: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861. ; 9:6, s. 1582-1592
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Journal article (peer-reviewed)abstract
- Because gastric infection by Helicobacter pylori takes place via the oral route, possible interactions of this bacterium with human salivary proteins could occur. By using modified 1- and 2-D bacterial overlay, binding of H. pylori adhesins BabA and SabA to the whole range of salivary proteins was explored. Bound salivary receptor molecules were identified by MALDI-MS and by comparison to previously established proteome maps of whole and glandular salivas. By use of adhesin-deficient mutants, binding of H. pylori to MUC7 and gp-340 could be linked to the SabA and BabA adhesins, respectively, whereas binding to MUC5B was associated with both adhesins. Binding of H. pylori to the proline-rich glycoprotein was newly detected and assigned to BabA adhesin whereas the SabA adhesin was found to mediate binding to newly detected receptor molecules, including carbonic anhydrase VI, secretory component, heavy chain of secretory IgA1, parotid secretory protein and zinc-alpha(2)-glycoprotein. Some of these salivary glycoproteins are known to act as scavenger molecules or are involved in innate immunity whereas others might come to modify the pathogenetic properties of this organism. In general, this 2-D bacterial overlay technique represents a useful supplement in adhesion studies of bacteria with complex protein mixtures.
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