title: Protein kinase C zeta is required for epidermal growth factor-induced chemotaxis of human breast cancer cells.
abstract: Chemotaxis plays an important role in cancer cell metastasis. In this study, we showed that epidermal growth factor (EGF) was a more potent chemoattractant than chemokine SDF-1alpha/CXCL12 for human breast cancer cell MDA-MB-231. Different inhibitors were used to evaluate the involvement of 12 protein kinase C (PKC) isotypes in the chemotactic signaling pathway. Chelerythrine chloride, an inhibitor of all PKC isotypes, blocked chemotaxis, whereas inhibitors of classic and novel PKC, such as Gö6976, Gö6850, or calphostin C, only impaired EGF-induced chemotaxis to a minor extent by not greater-than32% inhibition. These data suggested that atypical PKC were involved. The ligand-induced actin polymerization and cell adhesion were also similarly dependent on atypical PKC. Immunofluorescent staining showed an EGF-induced, LY294002-sensitive translocation of PKCzeta from the cytosol to the plasma membrane, indicating that EGF was capable of activating PKCzeta, probably via phosphoinositide 3 kinases. A myristoylated PKCzeta pseudosubstrate blocked the chemotaxis with an IC(50) of 20 mumol/L. To expand our investigation, we further showed that in MCF-7 and T47D, two additional human breast cancer cell lines, EGF-activated PKCzeta and the PKCzeta pseudosubstrate, inhibited chemotaxis. Taken together, our data suggest that PKCzeta is an essential component of the EGF-stimulated chemotactic signaling pathway in human breast cancer cells.
authors.affiliation: Department of Chemical Biology and State Key Laboratory of Molecular Dynamic and Stable Structures, College of Chemistry and Laboratory of Medical Immunology, School of Basic Medical Science, Peking University, Beijing, China.
authors.forename: Ronghua
authors.initials: R
authors.lastname: Sun
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Dalong
authors.initials: D
authors.lastname: Ma
authors.forename: Jiming
authors.initials: J
authors.lastname: Wang
authors.forename: Joost J
authors.initials: JJ
authors.lastname: Oppenheim
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
mesh_terms: D000470:Alkaloids; D053119:Benzophenanthridines; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology*; D045744:Cell Line, Tumor; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D002867:Chromones / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D010617:Phenanthridines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines; D020032:Tyrphostins / Q000494:pharmacology; D000099221:Protein Kinase C zeta
chemical_list: D000470:Alkaloids; D053119:Benzophenanthridines; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D002867:Chromones; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D009025:Morpholines; D010617:Phenanthridines; D011493:Protein Kinase C; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D020032:Tyrphostins; D000099221:Protein Kinase C zeta; C515255:CXCL12 protein, human; C101044:RTKI cpd; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C016299:chelerythrine