Phosphatidylinositol 3-kinase regulates early differentiation in human laryngeal keratinocytes

SummaryEpidermal growth factor receptor (EGFR) signaling regulates a variety of cellular functions, including proliferation, gene expression, and differentiation. Infection of laryngeal epithelial cells by human papillomaviruses causes recurrent respiratory papillomas, benign tumors characterized by an altered pattern of differentiation. Papilloma cells overexpress the EGFR and have constitutively active extracellular signal-regulated kinase (ERK) and enhanced phosphatidylinositol 3-kinase (PI3K) activity, but overexpression of the lipid phosphatase PTEN (Phosphatase and Tensin Homolog) reduces activation of Akt by PI3K. We hypothesized that the altered differentiation of papillomas reflects these changes in signaling from the EGFR-ERK and PI3K-Akt pathways and that one or both of these pathways is required for the normal differentiation process in mucosal epithelium. Inhibiting either the enzymatic activity or the synthesis of PI3K in uninfected laryngeal cells blocked expression of keratin-13 (K13), a protein induced during normal differentiation. In contrast, inhibiting activation of ERK had minimal effect. Using ribonucleic acid interference to reduce protein levels of integrinlinked kinase 1 or phosphoinositide-dependent protein kinase 1, intermediates in the activation of Akt by PI3K, or reducing levels of Akt-1 itself did not inhibit K13 expression by normal laryngeal keratinocytes. We conclude that PI3K activation is an important regulator of expression of K13, a marker for the normal differntiation process in human mucosal keratinocytes, that this function does not require activation of Akt-1, and that the failure to express K13 in papilloma cells is not because of reduction in activated Akt.

[1]  L. Cavanagh,et al.  Modulation of proliferation-specific and differentiation-specific markers in human keratinocytes by SMAD7. , 2004, Experimental cell research.

[2]  P. Hawkins,et al.  Phosphoinositide 3‐kinase‐dependent activation of Rac , 2003, FEBS letters.

[3]  R. Wu,et al.  Requirement of STAT3 Activation for Differentiation of Mucosal Stratified Squamous Epithelium , 2003, Molecular medicine.

[4]  C. Turner,et al.  Ca2+-dependent Localization of Integrin-linked Kinase to Cell Junctions in Differentiating Keratinocytes* , 2003, The Journal of Biological Chemistry.

[5]  P. Khavari,et al.  Inducible activation of Ras and Raf in adult epidermis. , 2003, Cancer research.

[6]  K. Sayama,et al.  Phosphatidylinositol 3-Kinase Is a Key Regulator of Early Phase Differentiation in Keratinocytes* , 2002, The Journal of Biological Chemistry.

[7]  A. Martelli,et al.  The nuclear phosphoinositide 3-kinase/AKT pathway: a new second messenger system. , 2002, Biochimica et biophysica acta.

[8]  C. Stournaras,et al.  Association of PI-3 kinase with PAK1 leads to actin phosphorylation and cytoskeletal reorganization. , 2002, Molecular biology of the cell.

[9]  Shishinn Sun,et al.  PTEN is a negative regulator of STAT3 activation in human papillomavirus-infected cells. , 2002, The Journal of general virology.

[10]  Marc W. Kirschner,et al.  A PtdInsP3- and Rho GTPase-mediated positive feedback loop regulates neutrophil polarity , 2002, Nature Cell Biology.

[11]  Lewis C Cantley,et al.  The phosphoinositide 3-kinase pathway. , 2002, Science.

[12]  R. Wu,et al.  Increased p50/p50 NF-κB Activation in Human Papillomavirus Type 6- or Type 11-Induced Laryngeal Papilloma Tissue , 2002, Journal of Virology.

[13]  J. Brissette,et al.  Role of the nude gene in epithelial terminal differentiation. , 2002, The Journal of investigative dermatology.

[14]  J. Gutkind,et al.  Rac1 and RhoG promote cell survival by the activation of PI3K and Akt, independently of their ability to stimulate JNK and NF-κB , 2002, Oncogene.

[15]  F. Watt,et al.  A role for mitogen-activated protein kinase activation by integrins in the pathogenesis of psoriasis. , 2001, The Journal of clinical investigation.

[16]  T. Tuschl,et al.  Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells , 2001, Nature.

[17]  S. Frisch,et al.  Anoikis mechanisms. , 2001, Current opinion in cell biology.

[18]  D. Alessi,et al.  Further evidence that 3‐phosphoinositide‐dependent protein kinase‐1 (PDK1) is required for the stability and phosphorylation of protein kinase C (PKC) isoforms , 2000, FEBS letters.

[19]  G. Scita,et al.  Signaling from Ras to Rac and beyond: not just a matter of GEFs , 2000, The EMBO journal.

[20]  T. Magnuson,et al.  Cross‐talk between epidermal growth factor receptor and protein kinase C during calcium‐induced differentiation of keratinocytes , 2000, Experimental dermatology.

[21]  B. Vanhaesebroeck,et al.  The PI3K-PDK1 connection: more than just a road to PKB. , 2000, The Biochemical journal.

[22]  B. Steinberg,et al.  Overexpression of PTEN/MMAC1 and decreased activation of Akt in human papillomavirus-infected laryngeal papillomas. , 2000, Cancer research.

[23]  H. Wakita,et al.  Activation of Epidermal Growth Factor Receptor Promotes Late Terminal Differentiation of Cell-Matrix Interaction-disrupted Keratinocytes* , 1999, The Journal of Biological Chemistry.

[24]  P. Edwards,et al.  Integrin-linked kinase regulates phosphorylation of serine 473 of protein kinase B by an indirect mechanism , 1999, Oncogene.

[25]  G. Thomas,et al.  Ribosomal S6 kinase signaling and the control of translation. , 1999, Experimental cell research.

[26]  T. Deerinck,et al.  Abnormal Morphogenesis But Intact IKK Activation in Mice Lacking the IKKα Subunit of IκB Kinase , 1999 .

[27]  S. Akira,et al.  Limb and skin abnormalities in mice lacking IKKalpha. , 1999, Science.

[28]  B. Steinberg,et al.  Elevation of the epidermal growth factor receptor and dependent signaling in human papillomavirus-infected laryngeal papillomas. , 1999, Cancer research.

[29]  T. Deerinck,et al.  Abnormal morphogenesis but intact IKK activation in mice lacking the IKKalpha subunit of IkappaB kinase. , 1999, Science.

[30]  M. Wigler,et al.  The lipid phosphatase activity of PTEN is critical for its tumor supressor function. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[31]  M. Tomic-Canic,et al.  Epidermal signal transduction and transcription factor activation in activated keratinocytes. , 1998, Journal of dermatological science.

[32]  M. Pittelkow,et al.  EGF-receptor tyrosine kinase inhibition induces keratinocyte growth arrest and terminal differentiation. , 1997, The Journal of investigative dermatology.

[33]  P. Cohen,et al.  Characterization of a 3-phosphoinositide-dependent protein kinase which phosphorylates and activates protein kinase Bα , 1997, Current Biology.

[34]  P. Cohen,et al.  Mechanism of activation of protein kinase B by insulin and IGF‐1. , 1996, The EMBO journal.

[35]  M. Symons,et al.  Rho family GTPases: the cytoskeleton and beyond. , 1996, Trends in biochemical sciences.

[36]  B. Allen-Hoffmann,et al.  Keratinocyte Growth Factor Inhibits Cross-linked Envelope Formation and Nucleosomal Fragmentation in Cultured Human Keratinocytes (*) , 1996, The Journal of Biological Chemistry.

[37]  J. Selkirk,et al.  Improved protein detection with a polyvinylidene fluoride transfer membrane for two-dimensional gel electrophoresis. , 1993, BioTechniques.

[38]  B. Steinberg,et al.  Laryngeal papilloma cells have high levels of epidermal growth factor receptor and respond to epidermal growth factor by a decrease in epithelial differentiation. , 1993, Cancer research.

[39]  G. Gill,et al.  Receptor tyrosine kinases , 1992, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[40]  K. Matsumoto,et al.  Epidermal cell differentiation inhibitor ADP-ribosylates small GTP-binding proteins and induces hyperplasia of epidermis. , 1992, The Journal of biological chemistry.

[41]  B. Steinberg,et al.  Abnormal differentiation of human papillomavirus-induced laryngeal papillomas. , 1990, Archives of otolaryngology--head & neck surgery.

[42]  J. Rubin,et al.  Human keratinocyte growth factor activity on proliferation and differentiation of human keratinocytes: Differentiation response distinguishes KGF from EGF family , 1990, Journal of cellular physiology.

[43]  B. Steinberg,et al.  Laryngeal keratinocytes show variable inhibition of replication by TGF-beta. , 1990, Journal of cell science.

[44]  D. Scudiero,et al.  Evaluation of a soluble tetrazolium/formazan assay for cell growth and drug sensitivity in culture using human and other tumor cell lines. , 1988, Cancer research.

[45]  B. Steinberg,et al.  Laryngeal papillomatosis: Clinical, histopathologic and molecular studies , 1987, The Laryngoscope.

[46]  S. Cohen,et al.  Epidermal growth factor , 1972, The Journal of investigative dermatology.

[47]  K. Wuepper,et al.  Biochemistry of transglutaminases and cross-linking in the skin. , 1983, The Journal of investigative dermatology.

[48]  B. Steinberg,et al.  Culture of Human Laryngeal Papilloma Cells in Vitro , 1982, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[49]  Benjamin Geiger,et al.  The catalog of human cytokeratins: Patterns of expression in normal epithelia, tumors and cultured cells , 1982, Cell.

[50]  V. Diehl,et al.  Molecular cloning and characterization of human papilloma virus DNA derived from a laryngeal papilloma , 1982, Journal of virology.

[51]  H Green,et al.  Involucrin synthesis and tissue assembly by keratinocytes in natural and cultured human epithelia , 1981, The Journal of cell biology.

[52]  Elaine Fuchs,et al.  Changes in keratin gene expression during terminal differentiation of the keratinocyte , 1980, Cell.

[53]  C. M. Wilson.  Studies and critique of Amido Black 10B, Coomassie Blue R, and Fast Green FCF as stains for proteins after polyacrylamide gel electrophoresis. , 1979, Analytical biochemistry.

[54]  H. Green,et al.  Seria cultivation of strains of human epidemal keratinocytes: the formation keratinizin colonies from single cell is , 1975, Cell.

[55]  H Green,et al.  Serial cultivation of strains of human epidermal keratinocytes: the formation of keratinizing colonies from single cells. , 1975, Cell.