Expression Of Keratinocyte Growth Factor Receptor Research Articles

Upregulation of VEGFR1 in a rat model of esophagogastric anastomotic healing

Introduction: Anastomotic leakage after gastrointestinal surgery is a significant cause of morbidity and mortality. Esophagogastric and colorectal anastomoses are vulnerable to leakage. Extended knowledge of growth factors and their receptors is needed to understand anatomic healing.Methods: The expression pattern of vascular growth factor receptor (VEGFR1-3), epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFRα/β) and keratinocyte growth factor receptor (KGFR) were analyzed by semiquantitative-PCR in the rat intestinal tract and in esophagogastric anastomosis 5d after surgery.Results: VEGFR1, VEGFR2, EGFR, KGFR and PDGFRα expression was observed throughout the intestinal tract including esophagus, stomach, small bowl and colon. VEGFR3 was not found in gastric samples and PDGFRβ expression was not detected in the small bowl.Semiquantitative analyses of the VEGFR1, PDGFRα and EGFR expression in esophagogastric anastomotic tissues revealed a 2-fold upregulation of the VEGFR1 in gastric samples, while no change was observed in the esophageal anastomotic side.Conclusion: Our results revealed a distinct expression pattern of the investigated growth factor receptors in rat intestinal tract. Showing higher expression levels of growth factor receptors at the gastric anastomotic tissue at the fifth postoperative day suggests a different contribution of the gastric and the esophageal side to the anastomotic healing.

AhR‑E2F1‑KGFR signaling is involved in KGF‑induced intestinal epithelial cell proliferation.

Keratinocyte growth factor (KGF) stimulates intestinal epithelial cell proliferation upon binding to the KGF receptor (KGFR). The activated aryl hydrocarbon receptor (AhR) serves an important role in the development of tissues by promoting the expression of AhR receptors, which can regulate cell proliferation. In the present study, the signaling pathway between AhR and KGFR in investigated with regards to KGF-induced intestinal epithelial cell proliferation. Male C57BL/6J wild type and AhR−/− mice, were randomized into four groups: Control, KGF, AhR−/− + KGF and AhR−/− (n=6 per group). The small bowel was harvested on day 5 post-treatment. LoVo cells were used to study signaling pathways in vitro and were divided into the following four treatment groups: DMSO, KGF, KGF + small-interfering (si)AhR and siAhR. In vivo, knockdown of AhR mRNA transcripts may abolish KGF-induced intestinal epithelial cell proliferation. Furthermore, KGFR expression was downregulated following knockdown or silencing of AhR expression in vivo and in vitro. The present study identified that the transcription factor E2F1 could regulate KGFR expression, and that siAhR treatment led to reduced expression of E2F1 in the nucleus and inhibited KGF-induced cell proliferation. In conclusion, the current results demonstrated that the AhR-E2F1-KGFR pathway is involved in KGF-induced intestinal epithelial cell proliferation.

Abstract 1074: Keratinocyte growth factor suppresses malignant phenotype of cutaneous squamous carcinoma cells

Abstract Keratinocyte growth factor (KGF, fibroblast growth factor-7) is a fibroblast-derived mitogen, which stimulates proliferation of epithelial cells. The expression of KGF by dermal fibroblasts is induced following injury and it promotes wound repair. However, the role of KGF in cutaneous carcinogenesis and cancer progression is not known. Here, we have examined the role of KGF in progression of squamous cell carcinoma (SCC) of the skin. The expression of KGF receptor (KGFR) mRNA was lower in cutaneous SCCs (n=6) than in normal skin samples (n=5). Expression of KGFR mRNA was detected in 6 out of 8 cutaneous SCC cell lines and the levels were downregulated by 24-h treatment with KGF. KGF did not stimulate SCC cell proliferation, but it reduced invasion of SCC cells through collagen. Gene expression profiling of three cutaneous SCC cell lines treated with KGF for 24 h revealed a specific gene expression signature characterized by upregulation of a set of genes specifically downregulated in SCC cells compared to normal epidermal keratinocytes, including genes with tumor suppressing properties (SPRY4, DUSP4, DUSP6, LRIG1, PHLDA1). KGF also induced downregulation of a set of genes specifically upregulated in SCC cells compared to normal epidermal keratinocytes, including genes associated with tumor progression (MMP13, MATN2, CXCL10, and IGFBP3). Downregulation of MMP-13 and KGFR expression in SCC cells and HaCaT cells was mediated via ERK1/2. Activation of ERK1/2 in HaCaT cells and tumorigenic Ha-ras-transformed HaCaT cells resulted in downregulation of MMP-13 and KGFR expression. These results provide evidence, that KGF does not promote progression of cutaneous SCC, but it suppresses the malignant phenotype of cutaneous SCC cells by regulating the expression of several genes differentially expressed in SCC cells, as compared to normal epidermal keratinocytes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1074. doi:1538-7445.AM2012-1074

Reduced expression of nuclear factor kB in oral mucosa undergoing preoperative chemoradiotherapy

Radiotherapy as well as chemotherapy in head and neck cancer induces severe oral mucositis. Even after healing of the mucositis, however, the oral mucosa looking atrophic is known to be susceptible to injury and infection. In order to investigate such vulnerability of mucosa, we immunohistochemically studied the expressions of Ki-67, proliferating cell nuclear antigen (PCNA), cyclin D1, nuclear factor (NF)-kB, and keratinocyte growth factor (KGF) receptor in the oral mucosal keratinocytes undergoing preoperative concurrent chemoradiotherapy for oral cancer, compared with those of the oral mucosa without such therapy. As a result, the expressions of Ki-67, PCNA, and cyclin D1 were decreased in the chemoradiotherapy-treated oral keratinocytes. Interestingly, NF-kB expression, which is known to be enhanced in oral mucositis, was reduced after chemoradiotherapy. The chemoradiotherapy had no effect on the expression of KGF receptor in oral keratinocytes. In conclusion, the vulnerability of oral mucosa undergoing chemoradiation may be associated with reduced NF-kB expression and impaired growth activity.

Keratinocyte Growth Factor Induces Gene Expression Signature Associated with Suppression of Malignant Phenotype of Cutaneous Squamous Carcinoma Cells

Keratinocyte growth factor (KGF, fibroblast growth factor-7) is a fibroblast-derived mitogen, which stimulates proliferation of epithelial cells. The expression of KGF by dermal fibroblasts is induced following injury and it promotes wound repair. However, the role of KGF in cutaneous carcinogenesis and cancer progression is not known. We have examined the role of KGF in progression of squamous cell carcinoma (SCC) of the skin. The expression of KGF receptor (KGFR) mRNA was lower in cutaneous SCCs (n = 6) than in normal skin samples (n = 6). Expression of KGFR mRNA was detected in 6 out of 8 cutaneous SCC cell lines and the levels were downregulated by 24-h treatment with KGF. KGF did not stimulate SCC cell proliferation, but it reduced invasion of SCC cells through collagen. Gene expression profiling of three cutaneous SCC cell lines treated with KGF for 24 h revealed a specific gene expression signature characterized by upregulation of a set of genes specifically downregulated in SCC cells compared to normal epidermal keratinocytes, including genes with tumor suppressing properties (SPRY4, DUSP4, DUSP6, LRIG1, PHLDA1). KGF also induced downregulation of a set of genes specifically upregulated in SCC cells compared to normal keratinocytes, including genes associated with tumor progression (MMP13, MATN2, CXCL10, and IGFBP3). Downregulation of MMP-13 and KGFR expression in SCC cells and HaCaT cells was mediated via ERK1/2. Activation of ERK1/2 in HaCaT cells and tumorigenic Ha-ras-transformed HaCaT cells resulted in downregulation of MMP-13 and KGFR expression. These results provide evidence, that KGF does not promote progression of cutaneous SCC, but rather suppresses the malignant phenotype of cutaneous SCC cells by regulating the expression of several genes differentially expressed in SCC cells, as compared to normal keratinocytes.

Polarized Endocytosis of the Keratinocyte Growth Factor Receptor in Migrating Cells: Role of Src-Signaling and Cortactin

Cell migration is a physiological process that requires endocytic trafficking and polarization of adhesion molecules and receptor tyrosine kinases (RTKs) to the leading edge. Many growth factors are able to induce motility by binding to specific RTK on target cells. Among them, keratinocyte growth factor (KGF or FGF7) and fibroblast growth factor 10 (FGF10), members of the FGF family, are motogenic for keratinocytes, and exert their action by binding to the keratinocyte growth factor receptor (KGFR), a splicing variant of FGFR2, exclusively expressed on epithelial cells. Here we analyzed the possible role of cortactin, an F-actin binding protein which is tyrosine phosphorylated by Src and is involved in KGFR-mediated cell migration, in the KGFR endocytosis and polarization to the leading edge of migrating cells upon ligand-induced stimulation. Biochemical phosphorylation study revealed that both KGF and FGF10 were able to induce tyrosine phosphorylation of Src and in turn of cortactin, as demonstrated by using the specific pharmacological Src-inhibitor SU6656, although FGF10 effect was delayed with respect to that promoted by KGF. Immunofluorescence analysis demonstrated the polarized localization of KGFR upon ligand stimulation to the leading edge of migrating keratinocytes, process that was regulated by Src. Moreover, we showed that the colocalization of cortactin with KGFR at the plasma membrane protrusions and on early endosomes after KGF and FGF10 treatment was Src-dependent. Further, by using a RNA interference approach through microinjection, we showed that cortactin is required for KGFR endocytosis and that the clathrin-dependent internalization of the receptor is a critical event for its polarization. Finally, KGFR expression and polarization enhanced cell migration in a scratch assay. Our results indicate that both Src and cortactin play a key role in the KGFR endocytosis and polarization at the leading edge of migrating keratinocytes, supporting the crucial involvement of RTK trafficking in cell motility.

Keratinocyte growth factor induces matrix metalloproteinase-9 expression and correlates with venous invasion in pancreatic cancer

Keratinocyte growth factor (KGF), also known as fibroblast growth factor-7, and KGF receptor (KGFR) play important roles in the growth of epithelial cells and are overexpressed in a variety of malignant epithelial tumors, including pancreatic ductal adenocarcinoma (PDAC). We previously reported that co-expression of KGF and KGFR in PDAC is associated with venous invasion, enhanced vascular endothelial growth factor A expression and poor prognosis. Matrix metalloproteinase-9 (MMP-9) is known to participate in the degradation of type IV collagen, which is a primary component of extracellular matrices in the vascular basement membrane. In the present study, we examined the expression and roles of KGF, KGFR and MMP-9 in human PDAC cell lines and tissues. Quantitative real-time polymerase chain reaction analysis demonstrated the expression of MMP-9 mRNA in all eight PDAC cell lines. KGF, KGFR and MMP-9 were, respectively, expressed in 27 (43%), 23 (37%) and 35 (56%) of 63 patients. Each expression of KGF, KGFR or MMP-9 correlated positively with venous invasion. Furthermore, expression of KGF or MMP-9 correlated positively with liver metastasis. KGF-positive cases exhibited shorter survival than KGF-negative cases, while KGFR and MMP-9 expression were unrelated to prognosis. Administration of recombinant human KGF increased MMP-9 expression in PDAC cells, while transient transfection with short hairpin RNAs targeting KGF transcripts reduced MMP-9 expression in PDAC cells. Moreover, recombinant human KGF significantly enhanced migration and invasion of PDAC cells. These findings suggest that KGF and KGFR promote venous invasion via MMP-9 in PDAC, and closely correlate with liver metastasis. The KGF/KGFR pathway may be a critical therapeutic target for PDAC metastasis.

Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats

To investigate the effect of keratinocyte growth factor (KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model. The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5% (v/v) acetic acid. Twenty-four hours after exposed to acetic acid, rats were divided into three experimental groups: control group, attenuated Salmonella typhimurium Ty21a strain (SP) group and SP strain carrying human KGF gene (SPK) group, and they were separately administered orally with 10% NaHCO(3), SP or SPK. Animals were sacrificed and colonic tissues were harvested respectively on day 3, 5, 7 and 10 after administration. Weights of rats, colonic weight/length ratio and stool score were evaluated. Histological changes of colonic tissues were examined by hematoxylin and eosin (HE) staining method. The expression of KGF, KGF receptor (KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting. Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67. In addition, superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in the homogenate were measured. Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups (body weight: 272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g, P < 0.01; colonic weight/length ratio: 115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm, P < 0.01). Moreover, pathological changes of damaged colon were improved in SPK group as well. After administration of SPK strain, KGF expression increased markedly from the 3rd d, and remained at a high level till the 10th d. Furthermore, KGFR expression and Ki67 expression elevated, whereas TNF-α expression was inhibited in SPK group. In the group administered with SPK, SOD activity increased significantly (d 5: 26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg, P < 0.01; d 7: 35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg, P < 0.01; d 10: 46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg, P < 0.01) and MDA contents decreased accordingly (d 7: 7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg, P < 0.01; d 10: 4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg, P < 0.01), compared with SP and control groups. KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids, and it may be a safe and effective treatment for ulcerative colitis.

Paracrine Loops of Keratinocyte Stimulation in Cholesteatoma Tissue

In relation to the keratinocyte growth factor (KGF) expression in cholesteatoma tissue, the inflammatory infiltrate present in this disease could play a relevant role in the paracrine stimulation of keratinocytes. Cholesteatoma is a temporal bone pathologic disease characterized by active proliferation of epithelial cells, with progressive growth and involvement of the neighboring middle/inner ear structures. The pathogenetic mechanism underlying the hyperproliferation of keratinocytes is not yet fully clarified. It has been suggested that keratinocyte proliferation and migration could be mediated by several autocrine and paracrine growth factors and their receptors. A previous study has reported that the expression of KGF receptor is increased in more differentiated areas of the cholesteatoma tissue, whereas the expression of the epidermal growth factor receptor is associated with proliferative and migratory areas of the lesion. Fresh cholesteatoma samples were collected during surgical procedures. Serial cryosections were examined by conventional hematoxylin and eosin or by immunofluorescence with antipancytokeratin antibodies. The ultrastructural features were analyzed by transmission electron microscopy. The expression of KGF, K1, and filaggrin in the samples was evaluated by quantitative reverse transcription-polymerase chain reaction and correlated with the dermal degree of inflammatory infiltrate and the presence of stromal cells. Increased expression of KGF was associated with strong levels of the inflammatory infiltrate. These results would suggest that KGF up-modulation is a consequence of fibroblast stimulation by inflammatory cells and that this paracrine loop could be responsible not only for the hyperproliferation of keratinocytes in cholesteatoma tissue but also for the deregulation of epidermal differentiation.

Effect of tumour-cell-derived or recombinant keratinocyte growth factor (KGF) on proliferation and radioresponse of human epithelial tumour cells (HNSCC) and normal keratinocytes in vitro

Purpose of this work was to test the effect of tumour-cell-derived keratinocyte growth factor (KGF) or recombinant KGF (palifermin) on cell proliferation and radiation response of human HNSCC cells and normal keratinocytes in vitro. Four tumour cell cultures derived from head and neck squamous cell carcinomas, primary keratinocytes, and immortalized keratinocytes were analysed. Fibroblasts, the natural source of KGF protein, served as controls. KGF expression was observed in primary and immortalized keratinocytes, fibroblasts, and in tumour cells, while significant KGF receptor expression was only found in keratinocytes. Recombinant KGF as well as tumour-cell-derived KGF caused a significant growth stimulation and radioprotection in keratinocytes, which was abolished by a neutralizing anti-KGF antibody. This indicates that tumour-cell-derived KGF is biologically active. In the tumour cell lines, no significant growth stimulation was induced by recombinant KGF, and the neutralizing antibody did not influence tumour cell growth or radiation response. Our results indicate that the normal, paracrine KGF regulatory mechanisms, which are based on KGF receptor expression, are lost in malignant cells, with the consequence of irresponsiveness of the tumour cells to exogenous KGF. In face of the amelioration of the radiation response of normal epithelia, demonstrated in various clinical and various preclinical animal studies, recombinant KGF represents a candidate for the selective protection of normal epithelia during radio(chemo) therapy of squamous cell carcinoma.

Keratinocyte growth factor accelerates compensatory growth in the remaining lung after trilobectomy in rats

In rats pulmonary resection is followed by lung compensatory growth. However, the molecular mechanism underlying lung compensatory growth remains unclear. Keratinocyte growth factor is expressed in lung tissue and is considered a possible mitogen for lung epithelial cells. The objectives of this study were to define the role of keratinocyte growth factor and its receptor in rat lung compensatory growth after trilobectomy and the effect of exogenous keratinocyte growth factor gene transfection. Adult Lewis rats were used. Right trilobectomy was performed in the operation group and sham thoracotomy in the sham group. In the operation group, keratinocyte growth factor-FLAG or FLAG expression vector was transfected directly into the lung by means of electroporation. Expression of keratinocyte growth factor and its receptor and alveolar cell proliferation index based on proliferating cell nuclear antigen levels were measured in the right lung at day 14 after the operation. Proliferating cell nuclear antigen, keratinocyte growth factor, and keratinocyte growth factor receptor expression in lung epithelial cells was significantly increased at day 4 after trilobectomy. Transfection of keratinocyte growth factor-FLAG expression vector resulted in further significant enhancement of proliferating cell nuclear antigen at day 4 after trilobectomy; however, the transfection of FLAG expression vector did not alter the enhancement of proliferating cell nuclear antigen. Exogenous expression of keratinocyte growth factor in the remaining lung by means of electroporation significantly augmented epithelial proliferation and decreased the average airspace distance (mean linear intercept). Our results implicate keratinocyte growth factor in the induction of alveolar epithelial cell proliferation for compensatory lung growth and indicate that overexpression of keratinocyte growth factor in the remaining lung by means of electroporation significantly augmented lung epithelial proliferation.

Silencing of Keratinocyte Growth Factor Receptor Restores 5-Fluorouracil and Tamoxifen Efficacy on Responsive Cancer Cells

BackgroundKeratinocyte growth factor receptor (KGFR) is a splice variant of the FGFR2 gene expressed in epithelial cells. Activation of KGFR is a key factor in the regulation of physiological processes in epithelial cells such as proliferation, differentiation and wound healing. Alterations of KGFR signaling have been linked to the pathogenesis of different epithelial tumors. It has been also hypothesized that its specific ligand, KGF, might contribute to the development of resistance to 5-fluorouracil (5-FU) in epithelial cancers and tamoxifen in estrogen-positive breast cancers.Methodology/Principal FindingsSmall interfering RNA was transfected into a human keratinocyte cell line (HaCaT), a breast cancer derived cell line (MCF-7) and a keratinocyte primary culture (KCs) to induce selective downregulation of KGFR expression. A strong and highly specific reduction of KGFR expression was observed at both RNA (reduction = 75.7%, P = 0.009) and protein level. KGFR silenced cells showed a reduced responsiveness to KGF treatment as assessed by measuring proliferation rate (14.2% versus 39.0% of the control cells, P<0.001) and cell migration (24.6% versus 96.4% of the control cells, P = 0.009). In mock-transfected MCF-7 cells, KGF counteracts the capacity of 5-FU to inhibit cell proliferation, whereas in KGFR silenced cells KGF weakly interferes with 5-FU antiproliferative effect (11.2% versus 28.4% of the control cells, P = 0.002). The capacity of 5-FU to induce cell death is abrogated by co-treatment with KGF, whereas in KGFR silenced cells 5-FU efficiently induces cell death even combined to KGF, as determined by evaluating cell viability. Similarly, the capacity of tamoxifen to inhibit MCF-7 and KCs proliferation is highly reduced by KGF treatment and is completely restored in KGFR silenced cells (12.3% versus 45.5% of the control cells, P<0.001).Conclusions/SignificanceThese findings suggest that selective inhibition of the KGF/KGFR pathway may provide a useful tool to ameliorate the efficacy of the therapeutic strategies for certain epithelial tumors.

Keratinocyte growth factor receptor (KGF-R) in cholesteatoma tissue

Conclusion. Distribution of the receptor for epidermal growth factor (EGF-R) and of the receptor for the keratinocyte growth factor (KGF-R) in cholesteatoma was found to differ in analogy with other epithelial tissues and accordingly to epidermal differentiation and intensity of paracrine stimulation. Moreover, both EGF-R and KGF-R expression was increased, suggesting a fair correlation with aggressiveness and recurrence rate of this pathology. Objectives. To obtain information on the biological behaviour of cholesteatoma by assessing the expression and localization of EGF-R and KGF-R and correlating their tissue distribution with that of cytokeratins as a marker of differentiation. Materials and methods. Cholesteatoma tissue was taken during tympanoplasty surgery and processed for indirect immunofluorescence. Murine monoclonal antibodies were tested for the different growth factor receptors and pancytokeratins analysed. Fluorescence intensity signal was measured on randomly captured digital images, using FISH 2000/HI software, with a pseudocolours generation module. Results. EGF-R was mostly expressed at the level of keratinocytes of the basal layer, while KGF-R signal was mainly distributed on the spinous and granular suprabasal layers that were also highly positive for cytokeratins. Significant correlation between the immunofluorescence signals was found for KGF-R and cytokeratins only, demonstrating that KGF-R expression is increased in more differentiated areas of the cholesteatoma tissue, while EGF-R is associated with proliferative and migratory portions of the lesion.

Expression and roles of keratinocyte growth factor and its receptor in esophageal cancer cells

The keratinocyte growth factor receptor (KGFR), also known as FGFR2 IIIb, is mainly localized in epithelial cells and is activated by the keratinocyte growth factor (KGF) that is predominantly synthesized by mesenchymal cells. In this study, we examined the roles of KGFR and KGF in human esophageal cancer (EC). In noncancerous esophageal tissues, KGFR was localized in epithelial cells from the basal region of the epithelium to the lower one-third of the epithelium, and KGF was weakly localized in the basal to parabasal epithelial cells. On the other hand, Ki-67 was localized in the parabasal cells. In EC tissues, KGFR and KGF were expressed in cancer cells in 22 and 37 of 54 patients, respectively. The coexpression of KGFR and KGF in cancer cells was detected in 14 of 54 (26%) patients. Clinicopathologically, KGFR expression correlated with the well-differentiated cell type of EC (p<0.001), and KGF expression correlated with lymphatic invasion and lymph node metastasis (p=0.004 and 0.021, respectively). The coexpression of KGFR and KGF in cancer cells correlated with the well-differentiated cell type of EC (p=0.001). KGFR-positive, KGF-positive and KGFR/KGF coexpression patients tended to have shorter survival rates, but the survival rates were not statistically significantly different (p=0.44, 0.059 and 0.112, respectively). In human EC cell lines (TE-1, TE-8 and TE-11), KGFR mRNA was expressed but no KGF mRNA was detected. The KGFR mRNA level was highest in TE-1 cells, derived from well-differentiated SCC and lowest in TE-8 cells. KGFR was detected in the cancer cell lines by Western blot analysis. Recombinant human KGF significantly stimulated the growth of TE-8 and -11 cells, derived from moderately differentiated SCC, but had no effect on TE-1 cell growth. These results suggest that KGFR expression correlates with the differentiation of a normal esophageal epithelium and the well-differentiated cell type of EC. On the other hand, KGF may induce the growth of some EC cells in a paracrine manner and closely correlates with lymphatic invasion and lymph node metastasis.

T helper type 1 cytokines and keratinocyte growth factor play a critical role in pseudoepitheliomatous hyperplasia initiation during cutaneous leishmaniasis

Pseudoepitheliomatous hyperplasia (PEH) is an exuberant proliferation of the epidermis. The underlying mechanism(s) that lead to PEH have not been completely elucidated. Here, we characterize PEH during the healing stages of cutaneous leishmanial ulcers in mice. During experimental cutaneous leishmaniasis (CL) C57BL/6 mice produce PEH, and BALB/c do not. A series of immunohistochemical and immunological studies were performed to identify the secretory products of PEH regulation. We observed that the distribution of TNF-alpha and IFN-gamma under PEH had a stripe-like diffuse pattern and localized in the upper part of the papillary dermis directly under the proliferating epidermis. Macrophages were identified as the major source of TNF-alpha (56.3%). The importance of IFN-gamma and TNF-alpha in PEH development was proven by the initiation of PEH after three intralesional injections of TNF-alpha and IFN-gamma every three days in infected BALB/c mice. In C57BL/6 mice, keratinocyte growth factor (KGF) expressing cells were found immediately under the basal membrane of the hyperplastic epidermis in comparison with sporadic KGF positive cells deep in the dermis of BALB/c mice. Quantitative RT-PCR analysis demonstrated increased KGF and KGF receptor expression in uninfected C57BL/6 mice as compared to BALB/c mice. These data indicate that Th1 cytokines and KGF play a critical role in PEH initiation during CL.

Membrane type 1 matrix metalloproteinase is necessary for distal airway epithelial repair and keratinocyte growth factor receptor expression after acute injury

Membrane type 1 matrix metalloproteinase (MT1-MMP) is a protease produced by airway epithelial cells in various diseases. Since other MMPs are involved in bronchial epithelial repair, we investigated the role of MT1-MMP in naphthalene-induced small airway injury and repair in wild-type (WT) and MT1-MMP-knockout (KO) mice. The degree of injury was similar in both strains, but the MT1-MMP KO mice were unable to reconstitute a normal, fully differentiated airway epithelium 28 days after injury. MT1-MMP was required for the proliferative response in distal airway epithelial cells, resulting in decreased cell density and airway epithelial cell differentiation in MT1-MMP KO mice. Surprisingly, EGF-mediated signaling was unaltered in MT1-MMP KO mice and therefore unrelated to the proliferative response. However, keratinocyte growth factor receptor (KGFR) expression was significantly upregulated before the proliferative response and markedly less evident in the distal airway epithelium of MT1-MMP KO mice. These results indicate MT1-MMP is involved in KGFR expression and epithelial cell proliferation after acute airway injury.

A protective role for keratinocyte growth factor in a murine model of chemotherapy and radiotherapy-induced mucositis

To evaluate the activity of palifermin (rHuKGF) in a murine model of mucosal damage induced by a radiotherapy/chemotherapy (RT/CT) regimen mimicking treatment protocols used in head-and-neck cancer patients. A model of mucosal damage induced by RT/CT was established by injecting female BDF1 mice with cisplatin (10 mg/kg) on Day 1; 5-fluorouracil (40 mg/kg/day) on Days 1-4, and irradiation (5 Gy/day) to the head and neck on Days 1-5. Palifermin was administered subcutaneously on Days -2 to 0 (5 mg/kg/day) and on Day 5 (5 mg/kg). Evaluations included body weight, organ weight, keratinocyte growth factor receptor expression, epithelial thickness, and cellular proliferation. Initiation of the radiochemotherapeutic regimen resulted in a reduction in body weight in control animals. Palifermin administration suppressed weight loss and resulted in increased organ weight (salivary glands and small intestine), epithelial thickness (esophagus and tongue), and cellular proliferation (tongue and salivary glands). Administration of palifermin before RT/CT promotes cell proliferation and increases in epithelial thickness in the oral mucosa, salivary glands, and digestive tract. Palifermin administration before and after RT/CT mitigates weight loss and a trophic effect on the intestinal mucosa and salivary glands, suggesting that palifermin use should be investigated further in the RT/CT settings, in which intestinal mucositis and salivary gland dysfunction are predominant side effects of cytotoxic therapy.

Regulation of epithelial cell growth factor receptor protein and gene expression using a rat periodontitis model

Regulation of epithelial cell behavior associated with periodontitis is not well elucidated but many responses will ultimately be regulated by growth factor receptors. Using a rat experimental periodontitis model, protein and gene expression of select growth factor receptors in junctional and pocket epithelium were examined. Periodontal disease was induced by daily topical application of lipopolysaccharide using an established protocol. Animals were killed at time 0 (control), and at 2 and 8 wk. Frozen tissue samples were collected from the right palatal gingival soft tissue, and the left periodontal tissues were decalcified and embedded in paraffin. Laser microdissection and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to quantify keratinocyte growth factor receptor (KGFR), hepatocyte growth factor receptor (HGFR), epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor 1 (FGFR1) gene expression, and in situ RT-PCR localized these increases to specific epithelial cells. Receptor protein expression was examined immunohistochemically. In cell culture, induction of HGFR and KGFR protein expression by serum, lipopolysaccharide and pro-inflammatory cytokines were examined using flow cytometry. Eight-week tissue samples exhibited histological changes consistent with periodontitis. KGFR and HGFR gene and protein expression were significantly induced at the 8 wk time point. KGFR expression was significantly up-regulated in basal and parabasal pocket epithelial cells, but HGFR was up-regulated throughout the pocket epithelium. In cell culture serum, lipopolysaccharide and pro-inflammatory cytokines, interleukin-1beta and tumour necrosis factor-alpha significantly induced KGFR protein receptor expression, but HGFR expression was only induced by serum. KGFR and HGFR are highly up-regulated in this model of periodontal disease and may play a significant role in regulating the proliferation and migration of pocket epithelium.

Keratinocyte Growth Factor Promotes Melanosome Transfer to Keratinocytes

Melanogenesis and melanosome transfer from the melanocytes to the neighboring keratinocytes are induced by ultraviolet radiation and modulated by autocrine and paracrine factors. Keratinocyte growth factor (KGF/fibroblast growth factor (FGF)7) is a paracrine mediator of human keratinocyte growth and differentiation. We evaluated the influence of KGF on melanosome transfer in co-cultures of keratinocytes and melanocytes. Immunofluorescence analysis using anti-tyrosinase and anti-human cytokeratin antibodies, phagocytic assays using fluorescent latex beads, and ultrastructural analysis indicated that KGF is able to induce melanosome transfer acting only on the recipient keratinocytes and as a consequence of a general role of KGF in the promotion of the phagocytic process. Inhibition of proteinase-activated receptor-2, to block the Rho-dependent phagocytic pathway, or of the Src family tyrosine kinases, to inhibit the Rac-dependent pathway, showed that KGF promotes phagocytosis through both mechanisms. Increased expression of the KGF receptor (KGFR) on the keratinocytes by transfection led to increased phagocytosis of latex beads following KGF treatment, suggesting that the KGF effect is directly mediated by KGFR expression and activation. Moreover, confocal microscopic analysis revealed that KGFR localize in phagosomes during KGF-induced phagocytosis, suggesting a direct role of the receptor in regulating both the early steps of uptake and the intracellular traffic of the phagosomes.

KERATINOCYTE GROWTH FACTOR RECEPTOR CORRELATES WITH VENOUS INVASION VIA VASCULAR ENDOTHELIAL GROWTH FACTOR IN PANCREATIC CANCER

Purpose: Keratinocyte growth factor (KGF)/fibroblast growth factor-7 (FGF-7), an angiogenic and mitogenic polypeptide that is mainly synthesized by mesenchymal cells, has been implicated in cancer growth and tissue development and repair. Its actions are dependent on binding to a specific cell-surface KGF receptor (KGFR). In the present study, we investigated the expression and role of KGF and KGFR in human pancreatic cancer tissues. Methods: Immunohistochemically, the expression of KGF, KGFR and VEGF in human pancreatic cancer tissues were examined. Moreover, we evaluated co-expression of KGF and KGFR, and correlation with clinicopathological factors. Result: KGFR was localized in cytoplasm and/or membrane of cancer cells in 22 of the 53 (41.5%) patients, and KGF immunoreactivity was detected in cytoplasm of cancer cells in 18 of the 53 (34.0%) patients. Clinicopathologically, KGF and KGFR expression was highly correlated with venous invasion respectively. Moreover, co-expression of KGF and KGFR correlated significantly with venous invasion, VEGF expression and poor prognosis. Conclusion: These findings suggest that co-expression of KGF and KGFR might play an important role in enhancing venous invasion in pancreatic cancer cases by modulating the capacity of angiogenesis.