involucrin and Metaplasia

Barrett's esophagus is characterized by a distinct Th2-predominant cytokine profile (IL-4) from in vivo or ex vivo evidence. The detailed role of cytokines in Barrett's esophagus, particularly whether Th2 cytokines are causative factors driving metaplastic processes, remains unknown. In this study, air-liquid interface-cultured human esophageal epithelial cells were stimulated by a Th2 cytokine, IL-4, and Th1 cytokines, TNF-α and IL-1β, continuously for 10 days. Barrier function was determined by transepithelial electrical resistance. Morphological changes were investigated by hematoxylin and eosin staining. Keratin profile (keratin 7, 8, 13, and 14) and squamous differentiation markers (involucrin) were investigated by RT-quantitative PCR, Western blotting, and immunohistochemical staining. Pharmacological inhibitors were used to identify the underlying cellular signaling. We report that IL-4, TNF-α, and IL-1β decrease barrier function, but only IL-4 significantly increases cell layers and changes cell morphology. IL-4 time dependently downregulates the expression levels of the squamous cell markers involucrin and keratin 13 and upregulates the expression levels of the columnar cell markers keratin 7 and 8. Neither TNF-α nor IL-1β shows any effect on these indexes. JAK inhibitor I and PI3K inhibitors significantly block the IL-4-induced changes in the levels of keratin 8 and 13. In conclusion, IL-4 inhibits squamous differentiation program of esophageal epithelial cells and induces differentiation toward columnar cells through the JAK/PI3K pathway. Thus IL-4 may be involved in the early stages of Barrett's esophagus development.

Topics: Barrett Esophagus; Biomarkers; Cell Differentiation; Cells, Cultured; Epithelial Cells; Esophagus; Humans; Immunohistochemistry; Interleukin-1beta; Interleukin-4; Keratins; Metaplasia; Protein Precursors; Signal Transduction; Tumor Necrosis Factor-alpha

Idiopathic pulmonary fibrosis (IPF) is the most common lung disease predisposing lung cancer. To clarify the early phase of epithelial abnormalities in IPF, we used an in vitro squamous metaplasia model, transforming growth factor beta1 (TGF beta1)-treated airway epithelial cells (BEAS-2B). The model repeated the expression of squamous epithelial character, such as involucrin, and keratin 6 and 14. DNA microarray analysis disclosed a unique expression signature in TGF beta1-treated airway epithelial cells, 20 specifically up-regulated genes including p63, jagged 1 (jag1) and the genes of structure proteins. Western blotting and RT-PCR analysis revealed that DeltaNp63alpha was the dominant isoform of p63 in our experimental model. Immunohistochemical analysis demonstrated the expression of p63 and jag1 in lung tissues of IPF. Inhibition of p63 with siRNA caused the down-regulation of jag1 expression, but not of involucrin, or keratin 6 and 14. Interestingly, the up-regulation of p63 was totally suppressed by N-acetyl-l-cysteine (NAC), but not by dexamethasone or pirfenidone. Thus, the p63-jag1 pathway may be up-regulated at an early phase of epithelial abnormalities in IPF, which can be overcome by NAC even in the TGF beta1-rich milieu.

Topics: Acetylcysteine; Biomarkers; Calcium-Binding Proteins; Cell Line, Tumor; Cluster Analysis; DNA-Binding Proteins; Epithelial Cells; Gene Expression Profiling; Humans; Intercellular Signaling Peptides and Proteins; Jagged-1 Protein; Keratin-14; Keratin-6; Membrane Proteins; Metaplasia; Oligonucleotide Array Sequence Analysis; Protein Isoforms; Protein Precursors; Pulmonary Fibrosis; Respiratory Mucosa; RNA, Small Interfering; Serrate-Jagged Proteins; Trans-Activators; Transcription Factors; Transforming Growth Factor beta1; Tumor Suppressor Proteins

Epidemiological evidence suggests that cigarette smoke induces squamous metaplasia in human tracheobronchial epithelium that can progress to lung squamous carcinoma. But it is not well understood how tracheobronchial epithelial cells transduce the signals that mediate cigarette smoke-induced squamous differentiation or squamous metaplasia. In the present study, we found that in vitro cigarette smoke components notably inhibited glycogen synthase kinase 3 (GSK3) and induced the expression of involucrin, a marker of squamous differentiation. The inactivation of GSK3 by two highly selective inhibitors, lithium and SB216763, also significantly enhanced involucrin expression in cultured porcine tracheobronchial epithelial cells (PTBECs). Moreover, we demonstrated that cigarette smoke components significantly promoted activator protein-1 (AP-1) binding activities to the upstream regulatory region of involucrin gene, and similar results were observed by further studies through using GSK3 inhibitors to imitate the effects of cigarette smoke components. Taken together, we conclude that GSK3 is involved in involucrin expression induced by cigarette smoke in PTBEC probably via negatively regulating AP-1 activity, implying a possible mechanism responsible for squamous differentiation induced by cigarette smoke.

Topics: Animals; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Enzyme Inhibitors; Gene Expression; Glycogen Synthase Kinase 3; Indoles; Lithium; Lung Neoplasms; Maleimides; Metaplasia; Precancerous Conditions; Protein Precursors; Respiratory Mucosa; Signal Transduction; Smoke; Swine; Transcription Factor AP-1

Overwhelming evidence has demonstrated tobacco smoke (TS) is causally associated with various types of cancers, especially lung cancer. Sustained epithelial cell hyperplasia and squamous metaplasia are considered as preneoplastic lesions during the formation of lung cancer. The cellular and molecular mechanisms leading to lung cancer due to TS are not clear. Mitogen-activated protein kinases (MAPK)/activator protein-1 (AP-1) can be activated by various stimuli and play a critical role in the control of cell proliferation and differentiation. To date, information on the response of the MAPK/AP-1 pathway during hyperplasia and squamous metaplasia induced by TS is lacking. We therefore investigated the effects of TS on the development of epithelial hyperplasia and squamous metaplasia, regulation of MAPK/AP-1 activation, and expression of AP-1-regulated cell cycle proteins and differentiation markers in the lungs of rats. Exposure of rats to TS (30 mg/m(3) or 80 mg/m(3), 6 h/day, 3 days/week for 14 weeks) dramatically induced cell proliferation and squamous metaplasia in a dose-dependent manner, effects that paralleled the activation of AP-1-DNA binding activity. Phosphorylated ERK1/2, JNK, p38 and ERK5 were significantly increased by exposure to TS, indicating the activation of these MAPK pathways. Expression of Jun and Fos proteins were differentially regulated by TS. TS upregulated the expression of AP-1-dependent cell cycle proteins including cyclin D1 and proliferating cell nuclear antigen (PCNA). Among the AP-1-dependent cell differentiation markers, keratin 5 and 14 were upregulated, while loricrin, filaggrin and involucrin were downregulated following TS exposure. These findings suggest the important role of MAPK/AP-1 pathway in TS-induced pathogenesis, thus providing new insights into the molecular mechanisms of TS-associated lung diseases including lung cancers.

Topics: Animals; Cell Proliferation; Cyclin D1; Enzyme Activation; Filaggrin Proteins; Hyperplasia; Intermediate Filament Proteins; JNK Mitogen-Activated Protein Kinases; Keratins; Lung Neoplasms; Male; Membrane Proteins; Metaplasia; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proliferating Cell Nuclear Antigen; Protein Precursors; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Rats; Rats, Inbred WKY; Signal Transduction; Smoking; Transcription Factor AP-1

Squamous differentiation/squamous metaplasia is often associated with endometrial adenocarcinoma and benign lesions, such as endometrial hyperplasia and chronic endometritis. Morules have distinct histological characteristics, and are referred to as squamous metaplasia or squamoid metaplasia.. To focus on the histological characteristics of morules and clarify the difference between morules and squamous differentiation.. Twenty endometrioid carcinomas with morules or squamous differentiation, five adenosquamous carcinomas, and eight non-carcinomatous endometrial lesions with morules were investigated. Numerous antibodies for epithelial membrane antigen (EMA), involucrin, cytokeratins, neuropeptides, and oncofetal antigens were used for immunohistochemistry. In situ hybridisation and polymerase chain reaction were used to detect human papillomavirus (HPV).. The morules observed were uniform cell clusters, with no squamous differentiation. They were immunonegative for epithelial antigens including involucrin, EMA, and cytokeratins, but were positive for neurone specific enolase. A few morules were immunopositive for acetylcholine esterase, and one case was positive for somatostatin; neither oncofetal nor proliferative cell markers, including blood group A, B, and AB, or other neuropeptides were demonstrated in the morules. HPV DNA was not found in either the morules in the carcinomas or in the benign lesions. However, true squamous differentiation tissue in four endometrioid carcinomas and two adenosquamous carcinomas was HPV positive using in situ hybridisation.. Morules are histologically distinct from squamous metaplasia/squamous differentiation tissue. Morules are thought to be neuroectodermal-like cell clusters, and are not infected with HPV. In contrast, some of the true squamous differentiation tissue was associated with HPV infection.

Topics: Adenocarcinoma; Adult; Aged; beta Catenin; Carcinoma, Squamous Cell; Cytoskeletal Proteins; DNA Mutational Analysis; DNA, Viral; Endometrial Neoplasms; Endometrium; Female; Humans; Immunohistochemistry; In Situ Hybridization; Metaplasia; Middle Aged; Papillomaviridae; Protein Precursors; RNA, Messenger; Trans-Activators; Transglutaminases

It has been reported previously in cases of adenosquamous carcinoma of the lung in Okinawa, a subtropical island 2000 km south of mainland Japan, that the squamous cell carcinoma components were positive for human papillomavirus (HPV) by non-isotopic in situ hybridisation (NISH). The adenocarcinoma cells adjacent to the squamous cell carcinoma components were enlarged and also positive for HPV. This is thought to indicate that after adenocarcinoma cells are infected with HPV, they undergo morphological changes, and that "squamous metaplasia" follows. In this present study, the effects of HPV transfection into adenocarcinoma cells were examined. The relation between the region expressing the HPV gene and squamous metaplasia was also studied.. Plasmid pBR322 containing HPV type 16 (HPV-16) was transfected into cultured colonic adenocarcinoma (DLD-1) and lung adenocarcinoma (PC-14) cells using the calcium phosphate method. Neomycin was used as a selection marker. The presence of HPV E1, E2, E4, E5, E6, E7, L1, and L2 mRNAs and also transglutaminase 1, involucrin, cyclin dependent kinases (CDKs), cyclins, caspases, apoptosis inducing factor, DNase gamma, Fas, and Fas ligand mRNAs in HPV transfected cells was investigated by means of reverse transcription polymerase chain reaction (RT-PCR). The G0-G1 cell population was analysed by flow cytometry. Morphological examination under light and electron microscopes was also carried out.. The virus transfected cells showed squamous metaplasia when they were injected into severe combined immunodeficient mice, expressing the high molecular weight keratin (Moll's number 1 keratin) and involucrin molecules immunohistochemically, and involucrin and transglutaminase I mRNAs by RT-PCR. The squamous metaplasia was most conspicuous in the HPV transfected DLD-1 cell when compared with HPV transfected PC-14 cells. Squamous metaplasia was most clearly demonstrated in one HPV transfected DLD-1 cell clone, which expressed not only E2 but also E6-E7 fusion gene mRNA. Viral L1 mRNA expression was absent in HPV transfected cell clones, and was not related to squamous metaplasia. The growth rate of HPV transfected cells was reduced. Transfection of the virus into the cultured adenocarcinoma cells increased the G0-G1 cell population greatly, as assessed by flow cytometer analysis. Furthermore, in the virus transfected cells, apoptosis was also observed by means of the terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling method.. HPV transfection into adenocarcinoma cells induced clear squamous metaplasia. One of the HPV transfected cell clones that expressed E2 and E6-E7 fusion gene mRNA showed the squamous metaplasia particularly clearly, and apoptosis was also demonstrated.

Topics: Adenocarcinoma; Animals; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Cycle; Cell Differentiation; DNA, Viral; Humans; Keratins; Lung Neoplasms; Metaplasia; Mice; Mice, SCID; Neoplasm Proteins; Neoplasm Transplantation; Papillomaviridae; Protein Precursors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Viral; Transfection; Tumor Cells, Cultured

Topics: Conjunctiva; Conjunctival Diseases; Humans; Immunohistochemistry; Keratins; Membrane Proteins; Metaplasia; Mucous Membrane; Protein Precursors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transglutaminases