|High mammographic density is associated with an increase in stromal collagen and immune cells within the mammary epithelium. |
Huo, CW; Chew, G; Hill, P; Huang, D; Ingman, W; Hodson, L; Brown, KA; Magenau, A; Allam, AH; McGhee, E; Timpson, P; Henderson, MA; Thompson, EW; Britt, K
Breast cancer research : BCR
Mammographic density (MD), after adjustment for a women's age and body mass index, is a strong and independent risk factor for breast cancer (BC). Although the BC risk attributable to increased MD is significant in healthy women, the biological basis of high mammographic density (HMD) causation and how it raises BC risk remain elusive. We assessed the histological and immunohistochemical differences between matched HMD and low mammographic density (LMD) breast tissues from healthy women to define which cell features may mediate the increased MD and MD-associated BC risk.Tissues were obtained between 2008 and 2013 from 41 women undergoing prophylactic mastectomy because of their high BC risk profile. Tissue slices resected from the mastectomy specimens were X-rayed, then HMD and LMD regions were dissected based on radiological appearance. The histological composition, aromatase immunoreactivity, hormone receptor status and proliferation status were assessed, as were collagen amount and orientation, epithelial subsets and immune cell status.HMD tissue had a significantly greater proportion of stroma, collagen and epithelium, as well as less fat, than LMD tissue did. Second harmonic generation imaging demonstrated more organised stromal collagen in HMD tissues than in LMD tissues. There was significantly more aromatase immunoreactivity in both the stromal and glandular regions of HMD tissues than in those regions of LMD tissues, although no significant differences in levels of oestrogen receptor, progesterone receptor or Ki-67 expression were detected. The number of macrophages within the epithelium or stroma did not change; however, HMD stroma exhibited less CD206(+) alternatively activated macrophages. Epithelial cell maturation was not altered in HMD samples, and no evidence of epithelial-mesenchymal transition was seen; however, there was a significant increase in vimentin(+)/CD45(+) immune cells within the epithelial layer in HMD tissues.We confirmed increased proportions of stroma and epithelium, increased aromatase activity and no changes in hormone receptor or Ki-67 marker status in HMD tissue. The HMD region showed increased collagen deposition and organisation as well as decreased alternatively activated macrophages in the stroma. The HMD epithelium may be a site for local inflammation, as we observed a significant increase in CD45(+)/vimentin(+) immune cells in this area.
|Results of a phase I/II clinical trial: standardized, non-xenogenic, cultivated limbal stem cell transplantation. |
Zakaria, N; Possemiers, T; Dhubhghaill, SN; Leysen, I; Rozema, J; Koppen, C; Timmermans, JP; Berneman, Z; Tassignon, MJ
Journal of translational medicine
To determine if a standardized, non-xenogenic, reduced manipulation cultivation and surgical transplantation of limbal stem cell grafts is a safe and effective treatment option for patients with total and partial limbal stem cell deficiency.In vitro cellular outgrowth and phenotype of the limbal epithelial cell and composite grafts were validated using a new protocol. Patients received either autologous (n = 15) or allogenic (n = 3) explants cultured using a standardized protocol free from xenogenic products. The resulting grafts were transplanted using a reduced manipulation surgical technique.The majority of cells (greater than 50%) displayed a progenitor phenotype typified by positive immunofluorescence for ∆Np63, CK14 and ABCG2 and low immunofluorescence for CK3/12 and desmoglein 3 proteins. The surgical protocol was designed to minimize manipulation and the graft itself was secured without sutures. The transplant recipients were followed for a mean of 24 months. Twelve of the 18 transplant recipients were graded as anatomically successful (67%), based on the defined success parameters. There was a significant reduction in corneal neovascularization, which was accompanied by an improvement in pain though not photophobia or central corneal opacity post transplant. The transplantation protocol showed no measureable effect on visual acuity.We conclude that this standardized culture system and surgical approach is safe and effective in reducing corneal neovascularization. The technique is free from animal contaminants and maintains a large proportion of progenitor cells. Although this technique did not improve visual function, restoring a functional epithelial cell layer and reducing corneal neovascularization provides an improved platform for a penetrating keratoplasty to ultimately improve visual function.
|Propagation and phenotypic preservation of rabbit limbal epithelial cells on amniotic membrane. |
Wang, DY; Hsueh, YJ; Yang, VC; Chen, JK
Investigative ophthalmology & visual science
To describe the phenotypic characteristics of a limbal epithelial cell sheet outgrowth from a limbal explant cultured on amniotic membrane.Immunofluorescent staining and confocal microscopy were used to examine the expressions of p63, Ki-67, keratins 3 and 14, connexin 43, and the integrin alpha6/beta4 and alpha3/beta1 subunits in corneal and limbal tissues in a limbal explant and epithelial outgrowth cultured for 2 weeks on amniotic membrane.The expression patterns of p63, Ki-67, keratins, integrins, and connexin 43 in a limbal explant with an epithelial outgrowth cultured for 2 weeks on amniotic membrane resembled those in freshly prepared limbus. Moreover, the distribution of integrin subunits in positive cells of the limbal explant and its epithelial outgrowth was similar to that of the corneal epithelial cells during wound repair.The epithelial cell sheet grown from a limbal explant on amniotic membrane exhibited a phenotype similar to that of the limbus, suggesting that amniotic membrane is a substrate capable of supporting the propagation and preservation of p63-positive limbal epithelial cells.
|Antibody markers of basal cells in complex epithelia. |
Purkis, P E, et al.
J. Cell. Sci., 97 ( Pt 1): 39-50 (1990)
In the course of immunohistochemical studies it has become apparent that there is a distinct phenotype of keratin expression that is shared by basal epithelial cells in a variety of different tissues. A basal cell can be defined as a cell in contact with a basal lamina but with no free luminal surface; this distinguishes it from a simple epithelial cell, which has a free luminal surface as well as basal lamina contact, and from stratifying suprabasal keratinocytes, which have neither basal lamina contact nor free luminal surface. All basal cells, whether they are in glandular ductal or secretory epithelia, or in stratified squamous epithelia, express the keratin pair K5 and K14. In this paper we describe monoclonal and polyclonal antibodies that are monospecific for both keratins 14 and 5 or are specific for denaturation-sensitive epitopes unique to basal cells, including five new monoclonal antibodies: LL001 and LL002 (to keratin 14), 2.1.D7 (to keratins 5, 6 and 8), and LH6 and LH8 (conformation-specific basal cell markers). These antibodies have been used to monitor the distribution of the basal cell phenotype and to demonstrate the expression of keratins 5 and 14 in this cell type, in both stratified epithelia and mixed epithelial glands. The consistent association of this keratin pair with basal cells suggests a possible specific function for these keratin in reinforcing epithelia under physical stress, whilst expression of these keratins may conflict with the differentiated functions of most simple epithelial cells.