Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Keywords: CELLS ; EXPRESSION ; tumor ; CELL ; Germany ; human ; PATHWAY ; GENE ; GENE-EXPRESSION ; GENES ; DIFFERENTIATION ; TUMORS ; COMPLEX ; COMPLEXES ; INDUCTION ; CONTRAST ; SKIN ; LOCALIZATION ; BENIGN ; keratin ; skin tumors ; epidermis ; FOLLICLE ; HAIR-FOLLICLES ; HUMAN TYPE-I ; MATRIX ; BETA-CATENIN EXPRESSION ; CORTEX ; HAIR FOLLICLE ; hair follicles,human,transcription factors,tumors ; HOXC13 ; INVOLUCRIN
    Abstract: Human hair follicles exhibit a complex pattern of sequential hair keratin expression in the hair matrix, cuticle, and cortex. In pilomatricomas, that is, benign skin tumors thought to arise from germinative matrix cells of the hair follicle and retaining morphological signs of cortical differentiation, this differential hair keratin pattern has been shown to be faithfully preserved in the lower and upper transitional cell compartments of the tumors. Here we show that also the co-expression of hair keratin hHa5 with its regulatory nuclear homeoprotein HOXC13 in matrix cells of the hair follicle is maintained in lower transitional cells of pilomatricomas. In contrast, the nuclear co-expression of LEF1 and beta-catenin, which in the hair follicle has been postulated to initiate cortex cell differentiation through the induction of hair keratin hHa1 expression (Merill et al, Genes Dev 15:1688-1705, 2001), is not preserved in upper transitional cells of pilomatricomas. Although these cells correctly express hHa1, they are completely devoid of LEF1 and nuclear LEF1/beta-catenin co-expression is shifted to a subpopulation of hair keratin-free basaloid cells of the tumors. These data imply that unlike the normal hair follicle, cortical differentiation in pilomatricomas is not under the control of the canonical Wnt signaling pathway
    Type of Publication: Journal article published
    PubMed ID: 15140206
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: CELLS ; EXPRESSION ; tumor ; CELL ; MICROSCOPY ; neoplasms ; COHORT ; SITE ; DIFFERENTIATION ; TUMORS ; MECHANISM ; INDUCTION ; KERATINOCYTES ; antibodies ; antibody ; immunohistochemistry ; FRANCE ; LENGTH ; FEATURES ; LIGHT ; LIFE ; methods ; keratin K77 ; adnexal tumor ; dermal duct tumor ; hidroacanthoma simplex ; PIGMENTED ECCRINE POROMA ; poroid hidradenoma ; poroma
    Abstract: Background: Poroid neoplasms comprise classic poroma (P), hidroacanthoma simplex (HS), dermal duct tumor (DDT), and poroid hidradenoma (PH). The 3 latter are rarely reported. Poroid cells in P have recently been identified as keratinocytes of the lowermost acrosyringium and the sweat duct ridge. Objectives: To investigate a large cohort of poroid neoplasms to better define the clinical and pathologic aspects of HS, DDT, and PH. To analyze the expression of discriminatory keratins in all 4 poroid neoplasms. Methods: 202 P, 11 HS, 17 DDT, 31 PH, and 5 composite tumors were examined under light microscopy, and 11, 9, 10, 15, and 2, respectively, by immunohistochemistry using anti-keratin antibodies, in particular, anti-K77, specific for luminal cells of the eccrine dermal sweat duct, and Ki-67 antibody. Results: HS appeared later in life (66.6 years old) than P, DDT, and PH. Whereas P, DDT, and PH displayed unspecific clinical aspects, HS had most frequently the aspect of a large seborrheic keratosis with well-defined borders. HS, DDT, and PH were absent on palms and soles, but were found on the trunk, the lower limbs, and the upper limbs. Similar pathologic features were observed in all tumors, that is, a majority of poroid cells expressing K14, islands of K10-positive and K77-negative large cells. K77 expression was limited to luminal cells of intact ductal structures within the tumors. Conclusions: Our data demonstrate the common histogenesis of the 4 poroid neoplasms, which seem to derive from the basal keratinocytes of the sweat duct ridge and the lower acrosyringium. The variable length of the sweat duct ridge may account for the variety of poroid neoplasms, according to the site of tumor induction along this structure
    Type of Publication: Journal article published
    PubMed ID: 20571345
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: CELLS ; EXPRESSION ; proliferation ; CELL ; Germany ; DIFFERENTIATION ; TUMORS ; CARCINOGENESIS ; KERATINOCYTES ; SKIN ; antibodies ; antibody ; NEOPLASIA ; immunohistochemistry ; PATTERNS ; skin carcinogenesis ; MUSCLE ; keratin ; SMOOTH-MUSCLE ; LAYER ; CYTOKERATINS ; ultrastructure ; RE ; PATTERN ; keratins ; HAIR FOLLICLE ; methods ; IMMUNOHISTOCHEMICAL ANALYSIS ; ENGLAND ; ACTIN ; EPITHELIAL KERATINS ; skin tumours ; eccrine sweat glands ; keratin K1 ; keratin K77 ; poroid cells ; skin appendages ; SWEAT-DUCT
    Abstract: Background Peripheral and luminal layers of eccrine sweat gland ducts are self-renewing structures. Proliferation is restricted to the lowermost luminal layer, but randomly scattered in the peripheral layer. Each layer exhibits differential expression of keratins K5/K14 and K6/K16. Keratin K1 occurs only in peripheral cells and the novel keratin K77 is specific for luminal cells. Objectives To investigate the expression of luminal (K77), peripheral (K1) and further discriminatory keratins in two eccrine sweat gland tumours: syringoma, thought to show differentiation towards luminal cells of intraepidermal sweat ducts and eccrine poroma, considered to arise from poroid cells, i.e. peripheral duct cells; and keratinocytes of the lower acrosyringium/sweat duct ridge differentiating towards cells of intradermal/intraepidermal duct segments. Methods Paraffin-embedded sections were examined by immunohistochemistry using several keratin, smooth muscle actin and Ki-67 antibodies. Results We confirmed the ductal nature of syringomas. Despite drastic morphological alterations in both layers, their keratin patterns remained almost undisturbed compared with normal ducts. In eccrine poroma epidermal keratins K5/K14 were ubiquitously expressed in all poroid cells. Cell islands deviating morphologically from poroid cells contained epidermal keratins K1/K10. K77 expression was limited to luminal cells of intact duct structures within the tumours. Conclusions Syringomas are benign tumours of luminal cells of the lowermost intraglandular sweat duct. Poroid precursor cells of poromas do not comprise peripheral duct cells nor do poromas differentiate towards peripheral or luminal duct cells. Instead, poroid cells consist only of keratinocytes of the lowermost acrosyringium and the sweat duct ridge and poromas tend to differentiate towards the cells of the upper acrosyringium
    Type of Publication: Journal article published
    PubMed ID: 18647305
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: MARKER ; NEW-YORK ; DIAGNOSIS ; tumor ; keratin ; USA ; -
    Type of Publication: Meeting abstract published
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: CELLS ; EXPRESSION ; CELL-PROLIFERATION ; Germany ; human ; DIFFERENTIATION ; TISSUE ; antibodies ; antibody ; PATTERNS ; gene expression ; NUMBER ; HUMAN GENOME ; LENGTH ; cytoskeleton ; EPIDERMAL DIFFERENTIATION ; intermediate filaments ; keratin ; SEGMENTS ; GENE DOMAIN ; human hair follicle ; INTERMEDIATE FILAMENT PROTEINS ; CYTOKERATIN EXPRESSION ; INNER-ROOT-SHEATH ; COMPARTMENTS ; RE ; IV ; GLAND ; EPITHELIAL KERATIN ; DUCT CELLS ; IMMUNOHISTOCHEMICAL ANALYSIS ; HYPERPROLIFERATION-ASSOCIATED KERATINS
    Abstract: In this study, we show that a novel human type II epithelial keratin, K1b, is exclusively expressed in luminal duct cells of eccrine sweat glands. Taking this luminal K1b expression as a reference, we have used antibodies against a plethora of epithelial keratins to systematically investigate their expression in the secretory globule and the two-layered sweat duct, which was divided into the intraglandular, intradermal, and intraepidermal (acrosyringium) segments, the latter being further subdivided into the sweat duct ridge and upper intraepidermal duct. We show that (i) each of the eccrine sweat gland tissue compartments expresses their own keratin patterns, (ii) the peripheral and luminal duct layers exhibit a sequential keratin expression, with both representing self-renewing cell layers, (iii) the intradermal duct and the sweat duct ridge display hitherto unknown length variations, and (iv) out of all cell layers, the luminal cell layer is the most robust layer and expresses the highest number of keratins, these being concentrated at the apical side of the cells to form the cuticle. We provide evidence that the cellular and intercellular properties of the peripheral and the luminal layers reflect adaptations to different functions
    Type of Publication: Journal article published
    PubMed ID: 16117782
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: CELLS ; EXPRESSION ; tumor ; carcinoma ; Germany ; neoplasms ; PATHWAY ; DIFFERENTIATION ; COMPLEX ; COMPLEXES ; TRANSCRIPTION FACTOR ; MEMBERS ; ASSOCIATION ; TRANSCRIPTION FACTORS ; NUMBER ; BENIGN ; FOLLICLE ; CATALOG ; MATRIX ; RE ; keratins ; LYMPH-NODE ; PULMONARY METASTASIS
    Abstract: Background: We have previously shown that benign pilomatricomas not only maintain the sequential expression of the hair matrix and precortex keratins hHa5 and hHa1 of normal hair follicles in their transitional cell compartment, but also preserve the association of hHa5 expression with that of its regulatory homeoprotein HOXC 13 in the lower transitional cell compartment. In contrast, hHa1 expression in the upper transitional cell compartment is uncoupled from the nuclear co-expression of the LEF1/beta-catenin complex seen in normal hair follicles (Cribier et al., J Invest Dermatol 2004; 122: 1078). Methods: Formalin-fixed paraffin sections of the tumor were examined using a panel of mono- and polyclonal hair and epithelial keratin antibodies as well as antibodies against HOXC 13, LEF1, and beta-catenin. Results: Morphologically, the malignant pilomatricoma investigated here clearly deviated from the described major tumor type by a large number of differently sized parakeratotic squamoid whorls emerging within the mass of basaloid cells and surrounded by cells remembering transitional cells, but only rarely containing shadow cells and signs of calcification. We show that hHa5/HOXC13 co-expression was maintained in transitional cell areas, in which hHa1 expression was much stronger than in benign pilomatricomas, but again uncoupled from concomitant nuclear LEF1/beta-catenin expression. Surprisingly, however, and in clear contrast to benign pilomatricomas, these transitional cells co-expressed the epithelial keratins K5, K14, and K17, with the latter being as strongly expressed as hHa1, both also staining the entire inner mass of the parakeratotic whorls. Conclusions: Although the malignant pilomatricoma investigated here was distinctive in that it contained a multitude of parakeratinizing whorls and no signs of calcification, it shared both hHa5/HOXC13 co-expression and disrupted hHa1/ beta-catenin-LEF1 expression in its transitional cell compartment around the whorls with benign pilomatricomas. However, in clear contrast to the latter, transitional cells of the malignant tumor also strongly expressed the epithelial keratins K5, K14, and K17. We speculate that the observed dominance of the epithelial differentiation pathway over the competing conventional shadow cell differentiation pathway may prevent massive calcification of the tumor
    Type of Publication: Journal article published
    PubMed ID: 16441405
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Hair keratins are specifically expressed in hair and nails. We previously demonstrated the expression of hair keratin basic 1 mRNA in pilomatrixomas. We recently developed a method for immunohistochemical staining of the group of acidic keratins, which have not yet been investigated in human tumours. Objectives To study the expression of eight members of the type I hair keratin subfamily in pilomatrixomas and other skin tumours of follicular origin. Methods We performed immunohistochemistry on paraffin sections of formalin-fixed pilomatrixomas (40), trichoepitheliomas (10), trichoblastomas (10), desmoplastic trichoepitheliomas (10) and basal cell carcinomas (10), using antibodies against type I hair keratins hHa1, hHa2, hHa3-II, hHa4, hHa5, hHa6, hHa7 and hHa8 as well as cytokeratin CK17. Results While CK17 was found in almost all tumours investigated, hair keratins were exclusively expressed in pilomatrixomas. Their expression was restricted to areas of transitional cells, located between outer basophilic matricial cells and an inner zone of eosinophilic shadow cells. The most frequently and most strongly expressed hair keratins were hHa1, hHa2, hHa5 and hHa8, whereas hHa4 and hHa6 were only weakly expressed. No positive staining was observed with anti-hHa3-II and anti-hHa7 antibodies. Hair keratin expression in intermediate maturation stage pilomatrixomas resembled that of normal hair follicles, with early matricial and cuticular keratins hHa5 and hHa2 being expressed in lower transitional cells, followed by expression of early cortex keratins hHa1 and hHa8 in intermediate transitional cells and the late cortex keratins hHa4 and hHa6 in upper transitional cells. The latter were, however, seen only in a few intermediate maturation stage pilomatrixomas and were generally absent in late-stage pilomatrixomas. Conclusions These changes in hair keratin expression patterns indicate that the maturation of pilomatrixomas towards large areas of shadow cells is associated with a gradual loss of differentiation-specific hair keratins. The complex hair keratin expression in pilomatrixomas is a further argument in favour of a hair matrix origin of this tumour.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...