title: Co-stimulation with stem cell factor and erythropoietin enhances migration of c-Kit expressing cervical cancer cells through the sustained activation of ERK1/2.
abstract: The cytokines erythropoietin (Epo) and stem cell factor (SCF), coupled with the cooperation between their receptors (EpoR and c-Kit), are essential components of normal physiological erythropoiesis. In earlier studies, we demonstrated the expression of c-Kit and EpoR in cervical cancer cells. It was identified that SCF is a survival factor, whereas Epo promotes cell proliferation. Cooperation between EpoR and SCF in cervical cancer has rarely been studied, despite the fact that cell migration and anchorage independent growth are considered initial steps in metastasis. Thus, the aim of this study was to analyse the effect of SCF and Epo alone, or in combination, on the migration and anchorage independent growth of two cervical cancer-derived cell lines. First, we demonstrated the expression of EpoR and c-Kit in the cell lines. Next, we evaluated anchorage independent growth, and identified that Epo and SCF produced a modest number of colonies, whereas the combination Epo/SCF induced a significantly higher number of colonies. Migration was then evaluated in Boyden chambers. Co-stimulation with Epo/SCF induced a significantly higher number of migrating cells than either cytokine alone. SCF-, Epo- and Epo/SCF-induced migration was inhibited by blocking phosphorylation of Janus kinase 2 (JAK2). Accordingly, western blot analysis demonstrated that the JAK2/signal transducer and activator of transcription-5 (STAT5) axis was activated in all cases. By contrast, inhibition of extracellular signal-related kinase (ERK) 1/2 abrogated migration induced by SCF and Epo/SCF only. Concurrently, Epo induced a modest, transient activation of ERK1/2, whereas SCF and Epo/SCF prompted a strong, sustained phosphorylation of ERK1/2. The results from this study have revealed that co-stimulation with Epo/SCF promotes migration and anchorage independent cell growth, and that co-signalling from EpoR and c-Kit converge on JAK2/STAT5 activation. Furthermore, SCF- and Epo/SCF-induced migration depends on the sustained activation of ERK1/2. These results indicate that co-signalling from different cytokine receptors induces migration, and this suggests that migratory behaviour may be regulated by the cooperative activity of Epo and SCF in cells expressing their cognate receptors.
authors.affiliation: Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, UNAM, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico.
authors.forename: Cristina
authors.initials: C
authors.lastname: Aguilar
authors.affiliation: Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, UNAM, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Aguilar
authors.affiliation: Instituto Nacional de Cardiología 'Ignacio Chávez', Departamento de Biología Celular, Colonia Sección 16, Tlalpan, C.P. 14080, Mexico City, Mexico.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Lopez-Marure
authors.affiliation: Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, UNAM, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jiménez-Sánchez
authors.affiliation: Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, UNAM, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico.
authors.forename: Leticia
authors.initials: L
authors.lastname: Rocha-Zavaleta
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D053614:Janus Kinase 2 / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism*; D017467:Receptors, Erythropoietin / Q000235:genetics / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D019089:Stem Cell Factor / Q000494:pharmacology*; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism*
chemical_list: D017467:Receptors, Erythropoietin; D050799:STAT5 Transcription Factor; D019089:Stem Cell Factor; D004921:Erythropoietin; D019009:Proto-Oncogene Proteins c-kit; D053614:Janus Kinase 2; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3