1,289 research outputs found
Multiple immunofluorescence labelling of formalin-fixed paraffin-embedded (FFPE) tissue
<p>Abstract</p> <p>Background</p> <p>Investigating the expression of candidate genes in tissue samples usually involves either immunohistochemical labelling of formalin-fixed paraffin-embedded (FFPE) sections or immunofluorescence labelling of cryosections. Although both of these methods provide essential data, both have important limitations as research tools. Consequently, there is a demand in the research community to be able to perform routine, high quality immunofluorescence labelling of FFPE tissues.</p> <p>Results</p> <p>We present here a robust optimised method for high resolution immunofluorescence labelling of FFPE tissues, which involves the combination of antigen retrieval, indirect immunofluorescence and confocal laser scanning microscopy. We demonstrate the utility of this method with examples of immunofluorescence labelling of human kidney, human breast and a tissue microarray of invasive human breast cancers. Finally, we demonstrate that stained slides can be stored in the short term at 4°C or in the longer term at -20°C prior to images being collected. This approach has the potential to unlock a large in vivo database for immunofluorescence investigations and has the major advantages over immunohistochemistry in that it provides higher resolution imaging of antigen localization and the ability to label multiple antigens simultaneously.</p> <p>Conclusion</p> <p>This method provides a link between the cell biology and pathology communities. For the cell biologist, it will enable them to utilise the vast archive of pathology specimens to advance their <it>in vitro </it>data into <it>in vivo </it>samples, in particular archival material and tissue microarrays. For the pathologist, it will enable them to utilise multiple antibodies on a single section to characterise particular cell populations or to test multiple biomarkers in limited samples and define with greater accuracy cellular heterogeneity in tissue samples.</p
p63 expression in normal skin and usual cutaneous carcinomas
Background: p63 is a p53 homologue that is mapped to chromosome 3q27. This gene encodes six different isoforms, which have either transactivating or dominant negative effects on p53-reporter genes. It has been described that in contrast to p53, p63 seems not to be associated with tumor predisposition, as neither p63 knockout mouse models nor germline p63 mutations are related to an increased risk of tumorigenesis. It has been demonstrated that p63 is a reliable keratinocyte stem cell marker and that it is involved in the maintenance of the stem cell population. Scant data on p63 expression in normal skin, basal cell carcinomas (BCCs), keratoacanthomas and squamous cell carcinomas (SCCs) have been reported. We herein evaluated p63 expression in 16 BCCs, one keratoacanthoma and 13 SCCs.
Methods: Immunohistochemistry according to the streptavidinbiotin-peroxidase technique, using the antibody 4A4 raised against all
p63 isoforms, was performed. p63 expression was evaluated in
epidermal cells and skin appendages. Semi-quantitative evaluation
(–, π, ππ, πππ) of p63 expression in BCCs, keratoacanthoma and
SCCs was carried out. Only nuclear expression was considered as
specific.
Results: p63 was expressed in the nuclei of epidermal basal and
suprabasal cells, in the cells of the germinative hair matrix and the
external root sheath of hair follicles, in the basal cells of the sebaceous
gland and in the myoepithelial/basal cells of the sweat glands. All
terminally differentiated cells were negative for p63. All BCCs showed
ππto πππ immunoreactivity. At variance, keratoacanthomas and
grade I and II SCCs showed variable p63 reactivity in a basal layerlike
distribution, whereas undifferentiated cells of grade III SCCs
showed ππto πππ positivity. A grade IV spindle SCC showed π
immunoreactivity. The SCCs in situ showed remarkable expression of
p63 in all cell layers. Terminally differentiated squamous cells were
either negative or showed only focal immunoreactivity in the
carcinomas.
Conclusions: p63 is consistently expressed in the basal cells of
epidermis and cutaneous appendages, including the basal/
myoepithelial cells of sweat glands. Based on our findings, the balance
of probabilities favors that p63 might play a role in the pattern of
differentiation and in the oncogenesis of usual carcinomas of the skin.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/5386/2001.
Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI)
Basal-like grade III invasive ductal carcinoma of the breast: patterns of metastasis and long-term survival.
INTRODUCTION: Cytokeratin (CK) 14, one of several markers expressed in normal myoepithelial/basal cells, is also expressed in a proportion of breast carcinomas. Previous studies have suggested that expression of such 'basal' markers predicts different biological behaviour, with more frequent lung and brain metastases and poorer prognosis than other carcinomas. METHODS: We performed CK14 immunohistochemistry on 443 grade III invasive ductal carcinomas with extended clinical follow-up (mean 116 months), and we correlated CK14 immunopositivity (basal-like phenotype) with clinicopathological criteria. RESULTS: Eighty-eight of 443 (20%) tumours showed CK14 expression. CK14-positive tumours were more likely to be oestrogen receptor-negative (p < 0.0001) and axillary node-negative (p = 0.001) than were CK14-negative cases. CK14-positive cases developed less bone and liver metastases (hazard ratio [HR] 0.49, p = 0.01, and HR 0.53, p = 0.035, respectively) but more frequent brain metastases (HR 1.92, p = 0.051). In patients without metastatic disease, disease-free survival in CK14-positive cases was significantly better than in CK14-negative cases (HR 0.65, p = 0.005). In patients with metastatic disease, however, CK14 positivity was associated with a poorer prognosis (HR 1.84, p = 0.001). The overall survival in CK14-positive and -negative patients was similar at 5 years (60% and 59%, respectively), but the long-term survival was better in CK14-positive patients (HR 0.69, p = 0.02). CONCLUSION: These results demonstrate that basal-like tumours differ in their biological behaviour from other tumours, with a distinct pattern of metastatic spread. Compared to other grade III tumours, basal-like tumours appear to have a relatively good long-term survival but survival after metastases is poor.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Differential Prox-1 and CD 31 expression in mucousae, cutaneous and soft tissue vascular lesions and tumors
The study of lymphatic vessels and lymphatic tumors has been hampered with difficulty due to the overlapping morphological features between blood and lymphatic endothelial cells, as well as to the lack of specific lymphatic endothelial markers. Over the last few years, lymphatic vessels and lymphangiogenesis have received great attention owing to their putative implications in terms of metastatic dissemination and the promise of targets for lymphangiogenic therapy. Prox-1 is a nuclear transcription factor that plays a major role during embryonic
lymphangiogenesis and is deemed to be a useful marker for differentiating lymphatic endothelial cells from the other blood vessels endothelial cells. Here, we describe a double-immunostaining strategy for formalin-fixed, paraffinembedded tissues that aims at evaluating the distribution of Prox-1 and CD 31 – a cytoplasmic pan-endothelial marker
-in a series of 28 mucousae, cutaneous and soft tissue vascular lesions and tumors, including hemangiomas, lymphangiomas, lymphangiectasia, and Kaposi’s sarcomas. Our results showed that in non-lesional mucousae and skin, Prox-1 decorated exclusively the nuclei of endothelial cells in lymphatic vessels. Prox-1 stained almost all the benign lymphatic vascular lesions/tumors (91%) and was absent or only focally positive in 75% of blood vascular tumors. CD 31 stained endothelial cells of blood vessels of superficial and deep dermal plexuses, lymphatics, and all blood vascular lesions/tumors. Kaposi’s sarcomas were all positive for both CD 31 and Prox-1 markers. In conclusion, although Prox-1 expression in vascular lesions/tumors was not entirely restricted to tumors with known lymphatic
differentiation, CD 31/Prox-1 double-immunolabeling can be used as an adjunct marker to identify lymphatic vessels in routinely processed formalin-fixed, paraffin-embedded samples
Novel and classic myoepithelial/stem cell markers in metaplastic carcinomas of the breast
Metaplastic carcinomas of the breast (MCBs) are unusual neoplasms
characterized by an admixture of glandular epithelial
components, which frequently exhibit features of squamous
differentiation, and mesenchymal malignant components. Regardless
of the presence of myoepithelial features in MCB, no
consensus concerning their putative histogenesis has yet been
achieved. Recently, novel putative myoepithelial markers have
been developed, including p63, maspin, and P-cadherin. We
assessed the expression of these myoepithelial markers in
MCBs and compared their expression with classic myoepithelial
markers. Immunohistochemistry using the streptavidin–
biotin–peroxidase complex technique with antibodies raised
against p63, maspin, P-cadherin, actin (clones CGA7, 1A4 and
HHF35), cytokeratin 14 (Ck14), and vimentin was performed
on 16 MCBs (7 matrix-producing MCBs, 6 adenosquamous
MCBs, and 3 MCBs with heterologous elements). In healthy
breast lobules and ducts adjacent to the tumors, myoepithelial
cells showed distinctive and consistent immunoreactivity for
p63, maspin, P-cadherin, actin, S-100 protein, and Ck14. Matrix-
producing MCBs were positive for maspin in all cases, for
p63 in 4 of 7 cases, and for P-cadherin in 4 of 7 cases. Adenosquamous
MCB showed immunoreactivity for p63, maspin,
and P-cadherin in 5 of 6 cases. All novel myoepithelial markers
and Ck14 decorated squamous cell islands. MCBs with heterologous
elements were positive for p63 in 1 case, for maspin in
all 3 cases, and for P-cadherin in 2 cases. All cases showed at
least one of the novel myoepithelial markers. Eleven of 16
cases were positive for actin. Eleven of 14 cases reacted with
Ck14, and all cases that stained for S-100 protein (9 of 9) and
vimentin (13 of 13) were also positive. Based on our findings,
the balance of probabilities favors that MCBs may have a basal
or myoepithelial cell histogenesis and differentiation.Fundacão para a Ciência e a Tecnologia (FCT), Ministério da Ciência e Tecnologia (MCT) - SFRH/BD/5386/2001
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