Agenda of the 84thSSBC Business Meeting, Thursday 4th November, University of Dundee
- Apologies:
- Approval of Minutes of 83rd meeting:
- Finances:
- New members:
- Matters arising:
- AOCB:
- Next meeting:
Minutes of the 83rd SSBC Business Meeting, Thursday20th May 2010, University of Edinburgh.
- Apologies:
Received from Keith Thoday, Sally Ibbotson, Malcolm Hodgins, Roddie McKenzie, Albena Dinkova-Kostova, Patricia Martin, Sheena Russell, David Greenhalgh
- Approval of Minutes of 82nd meeting:
These were adopted. Proposed by Julie Woods; 2nd by floor.
- Finances:
Income was £420 (28 x £15) and five people paid membership fees (£50). Total income from the meeting was £470.
Expenditure was £60 for teas & coffee; Lunch was £200.70. Total expenditure was £260.70
As of 19th May 2010 the treasurer account contained £1099.66
- New members:
Vijitha Sathiaseelan was proposed by Adrian Mason and seconded by Nicki Traynor.
- Matters arising
£25 is owed to Andy Cassidy for website costs.
Andy South suggested speakers for future meetings: Ryan O’Shaughnessy, ICH, University College London and Richard Grose, Institute of Cancer, Barts & The London School of Medicine & Dentistry.
We were saddened to hear of the death of Dr Sue Morley, a key member of the club and an enthusiastic contributor. She will be greatly missed and fondly remembered by her friends and colleagues.
- AOCB:
- Next meeting:
The next meeting will take place in October/November 2010 in Dundee. GCU have offered to host the spring meeting in 2011.
Programme for the 84th SSBC, Thursday 4th November, University of Dundee
10.15-10.45:Registration & Coffee
10.45-11.00Business Meeting. Chair: Richard Weller
11.00-12.20:Morning Session
11.00-11.20:Porphyria Cutanea Tarda.
J.A. Woods & R.S. Dawe, Photobiology Unit, University of Dundee.
11.20-11.40:Insulin-like growth factor 1 (IGF-I), insulin-like growth factor binding protein 5 (IGFBP-5) and connexins modulate cell migration in human keratinocyte and organotypic skin models.
C.S.Wright, D. Flint and P.E.M. Martin, Department of Biological & Biomedical Sciences, Glasgow Caledonian University.
11.40-12.00:Action Spectra of Photoallergic Contact Dermatitis for Benzophenone-3 and Etafenamate.
A.Kerr, and J.Ferguson, Photobiology Unit, University of Dundee.
12.00-12.20:STAT3 as a Potential Substrate for Protein Tyrosine Phosphatase Receptor Delta (PTPRD) in Cutaneous SCC.
M. Romanowska, S.R. Lambert*, K. Purdie*, C.A. Harwood, J. Foerster and C.M. Proby, Cancer Research UK Skin Tumour Laboratory, Centre for Oncology and Molecular Medicine, Ninewells Hospital & Medical School, University of Dundee; * Centre for Cutaneous Research, Barts and the London Queen Mary’s School of Medicine.
12.20-13.10:Lunch
Afternoon Session:
13.10-14.00Invited Speaker: Dr Ryan O’Shaughnessy
Molecular Mechanisms of Epidermal Barrier Acquisition and Barrier Dysfunction.
The UCL Institute of Child Health, London.
Insulin-like growth factor 1 (IGF-I), insulin-like growth factor binding protein 5 (IGFBP-5) and
connexionsmodulate cell migration in human keratinocyte and organotypic skin models.
C.S.Wright, D. Flint and P.E.M. Martin, Department of Biological & Biomedical Sciences, Glasgow Caledonian University.
In diabetic skin the IGF-I:IGFBP-5 ratio is perturbed, and in other organs increased IGFBP-5 leads to fibrosis. Altered IGF-I:IGFBP-5 may contribute to impaired cell migration in non-healing diabetic wounds. We have previously shown that the connexin mimetic peptide, Gap27, directly targeted to the extracellular loop of connexin 43 (Cx43) increases rates of ‘wound’ closure in human skin organotypic models by reducing of connexin-mediated communication (CMC). Differences in Gap27-induced scrape-wound closure occur in euglycaemia and euinsulinaemia or hyperglycaemia and hyperinsulinaemia, and this study examined the relative roles of insulin-like growth factor 1 (IGF-I), insulin-like growth factor binding protein 5 (IGFBP-5) in this system.
Cells were treated for 5 days with 5.5 mM glucose and 1 nM insulin, or 25 mM glucose and 10 nM insulin. Subsequently, migration studies examined rates of scrape-wound closure in cell monolayers and organotypic skin models over 48 hours in cells in these conditions in the presence or absence of 100 ng/ml IGF-I, 4 μg/ml IGFBP-5 and 100 μM Gap27. Immunocytochemistry with confocal microscopy was used to examine the effect of IGF-I and IGFBP-5 on Cx43 and Cx26 distribution in organotypic models.
Addition of IGF-I increased scrape-wound closure in both euglycaemia/euinsulinaemia and hyperglycaemia/hyperinsulinaemia in 2D and 3D cultures (P < 0.001). Further, the presence of IGFBP-5 counteracted this effect (P < 0.05). Gap27 increased wound closure in addition to that seen with IGF-I, and overrode the inhibitory effects of IGFBP-5 (P < 0.001). Under euglycaemia/euinsulinaemia Cx43 and Cx26 were differentially expressed in organotypic skin models with basal Cx43 and Cx26 in the upper layers; with low amounts of phosphorylated Cx43 (Cx43-ser368). Gap27 treatment increased Cx43-ser368 levels. Organotypic models treated with hyperglycaemia/hyperinsulinaemia showed an upregulation of Cx26 expression, with Cx43 still present in the basal layers, and an upregulation of Cx43-ser368. This seemed to be further enhanced following Gap27 treatment. Treatment with IGF-I did not alter these observations.
Gap27 blocked CMC and increased cell migration rates in both euglycaemia/euinsulinaemia andhyperglycaemia/hyperinsulinaemia. IGF-1 increased migration of Gap27-treated cells further, while IGFBP-5retarded them. Gap27 overcame the inhibited migration due to IGFBP-5. The connexin expression pattern observed in organotypic models suggests that IGF-I does not influence connexin expression status in epidermal tissue. IGFBP-5 plays a central role in a diabetic environment and can impede IGF-I mediated effects. Thus in diabetic tissue where the IGF-I:IGFBP-5 ratio is disturbed, Gap27 can be predicted to have a positive effect on chronic wound healing.
STAT3 as a Potential Substrate for Protein Tyrosine Phosphatase Receptor Delta (PTPRD) in Cutaneous SCC.
M. Romanowska, S.R. Lambert*, K. Purdie*, C.A. Harwood, J. Foerster and C.M. Proby, Cancer Research UK Skin Tumour Laboratory, Centre for Oncology and Molecular Medicine, Ninewells Hospital & Medical School, University of Dundee; * Centre for Cutaneous Research, Barts and the London Queen Mary’s School of Medicine.
Cutaneous squamous cell carcinomas (cSCC) are the second most commonly diagnosed cancers in fair-skinned people, but the molecular mechanisms involved in SCC tumorigenesis remain poorly understood. Previously, we have identified abnormalities in PTPRD gene in cutaneous SCC that are significantly associated with metastatic tumours (p 0.007). Two thirds (68%) of poorly differentiated and/or metastatic cSCC show microdeletions within 5’ UTR (32%) or LOH (36%) across the locus, and one third (37%) of cSCC without microdeletions have somatic mutations in PTPRD.
Signal Transducer and Activator of Transcription-3 (STAT3) is tumor-associated transcription factor that is activated by phosphorylation of Tyr705 and/or Ser727, and phospho-STAT3 (p-STAT3) also contributes to tumorigenesis in various tumors, including cSCC. Based on in vitro studies, Veeriah and colleagues have reported that p-STAT3 is a substrate for PTPRD in glioblastoma.
In order to investigate PTPRD protein expression, an antibody was developed against the extracellular fibronectin-type III domain and validated. Endogenous PTPRD was detected in NHK and fibroblasts, and in cSCC-derived keratinocytes. Immunofluorescence of cSCC-derived keratinocytes and NHK showed a predominantly perinuclear, but also some membranous, localisation. A series of paraffin embedded tumour samples (n= 32) and normal skin (n=5) was subjected to immunohistochemistry and the immunostaining quantified against internal controls (hair follicle, sebaceous or eccrine glands). In normal skin PTPRD was limited to the basal layers, with membrane associated polarised pattern. Well differentiated cSCC showed a similar polarized membrane associated pattern whereas poorly differentiated cSCC showed a strong, diffuse and mis-localized immunoreactive signal.
Seventeen cSCC for which the genetic status of PTPRD was known were analysed for p-STAT3 immunoreactivity using commercial antibody to p-Tyr705. cSCC panel used included 5 WD, 5 MD and 7 PD tumours. There was no apparent correlation between deletion or LOH at the PTPRD locus and pSTAT3 positivity. Immunoreactivity of p-STAT3 did appear to correlate with differentiation status, with 80% (4/5) of WD tumours showing positive signal, compared to 14% (1/7) of PD cSCC suggesting possible correlation with PTPRD expression/phosphatase activity.
In normal skin, PTPRD was limited to the basal layers, with a striking, membrane-associated pattern of immunoreactivity. In skin malignancies, the well differentiated cSCC showed a mostly polarized, membrane-associated pattern, whereas poorly differentiated tumours showed strong, diffuse and mis-localised immunostaining. However, the localisation of PTPRD in poorly differentiated tumours is clearly abnormal and the functional significance of this is unclear. The immunoreactivity patterns are consistent with the proposed role of pSTAT3 as a substrate for PTPRD. Further studies are now needed to confirm this and to clarify the role of PTPRD in cSCC pathogenesis.