Die Bedeutung von Intermediärfilamentveränderungen für die Metastasierung und die Prognose des Mammakarzinoms

Zusammenfassung

Einleitung

Der Verlust der epithelspezifischen Keratine (K) zugunsten des mesenchymalen Vimentins kennzeichnet einen strukturellen Wandel der Karzinomzelle, welcher zu einer Steigerung der Plastizität und Motilität der Tumorzelle führt. Die Bedeutung dieses Strukturproteinwechsels für die Metastasierung und die Prognose des Mammakarzinoms wurde in dieser Studie überprüft.

Material und Methode

Die Expression der epithelialen Keratine K8 und K19 sowie des mesenchymalen Vimentins wurde immunhistochemisch (APAAP) in 80 invasiv duktalen Mammakarzinomen sowie in 6 humanen Mammakarzinomzelllinien untersucht. Der Krankheitsverlauf wurde über 10 Jahre zurückverfolgt.

Ergebnisse

K8 wurde nur in 27,5 % der Tumoren in physiologischen Mengen exprimiert. K8-positive Karzinome hatten eine signifikant bessere Überlebensrate als K8-negative Karzinome (DFS/OS: p < 0,004). K19 wurde in 35 % der Tumoren nachgewiesen und hatte keinen prognostischen Einfluss. In 21,3 % der Tumoren wurde eine Expression des mesenchymalen Vimentins beobachtet, welche mit einer signifikanten Prognoseverschlechterung verbunden war (DFS: p < 0,003, OS: p < 0,006). Entsprechend konnte in den Zelllinien mit steigendem metastatischen Potenzial eine schrittweise Suppression von K8 und K19 zugunsten einer aberranten Vimentinexpression nachgewiesen werden.

Schlussfolgerung

Offensichtlicherweise stellt der Erhalt des luminalen Keratins 8 beim Mammakarzinom ein Metastasierungshindernis dar, wogegen die Suppression von K8 sowie die Neuexpression des mesenchymalen Vimentins eine Metastasierung begünstigt. Grundlegende Veränderungen der Intermediärfilamente scheinen daher entscheidende Schritte im Metastasierungsprozess des Mammakarzinoms darzustellen.

Summary

Objective

In cancer cells, loss of the epithelial protein keratin and acquisition of the mesenchymal vimentin are associated with increased motility and plasticity. We studied the influence of intermediate filament changes on the metastasis and prognosis of patients with breast cancer.

Methods

Paraffin-embedded specimens of 80 invasive ductal breast cancers and six human breast cancer cell lines were analyzed immunohistochemically for the expression of the keratins 8 and 19 and vimentin. The clinical follow-up was longer than 10 years.

Results

High expression of keratin 8 was found in 27.5 % of tumors. Patients with keratin-8-positive tumors had longer disease-free and overall survival compared with those with keratin-8-negative tumors (P < 0.004). Keratin 19 was expressed in 19 % of tumors and its presence was not correlated with outcome. Vimentin was expressed in 21 % of tumors and was associated with unfavorable disease-free and overall survival (P < 0.003 and 0.006, respectively). Cell lines with increasing metastatic potential had a loss of keratin expression in favor of an aberrant expression of vimentin.

Conclusion

Loss of keratin 8 and aberrant expression of vimentin are associated with early metastasis and a poor prognosis in breast cancer. Changes in the intermediate filament proteins appear to be important steps in the malignant progression of breast cancer.

Literatur

• 1 Bartek J. et al . Patterns of expression of keratin 19 as detected with monoclonal antibodies in human breast tissues and tumours.  Int J Cancer. 1985;  36 299-306
• 2 Boyer B. et al . Rearrangement of desmosomal and cytoskeletal proteins during the transition from epithelial to fibroblastoid organisation in cultured rat bladder carcioma cells.  J Cell Biol. 1989;  109 1495-1509
• 3 Braun S, Pantel K. Micrometastatic bone marrow involvement: detection and prognostic significance.  Med Oncol. 1999;  16 154-165
• 4 Cordell J L. et al . Immunoenzymatic labeling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP complexes).  J Histochem Cytochem. 1984;  32 219-229
• 5 Debus E. et al . Immunhistochemical distinction of human carcinomas by cytokeratin typing with monoclonal antibodies.  Am J Pathol. 1984;  114 121-130
• 6 Dogmala W. et al . Vimentin is preferentially expressed in human breast carcinoma with low estrogen receptor and high Ki-67 growth fraction.  Am J Pathol. 1990;  136 219-227
• 7 Eichner R. et al . The role of keratin subfamilies and keratin pairs in the formation of human epidermal intermediate filaments.  J Cell Biol. 1986;  102 1767-1777
• 8 Evans R M. Vimentin - the conundrum of the intermediate filament gene family.  Bioessays. 1998;  29 79-86
• 9 Franzen B. et al . Analysis of polypeptide expression in benign and malignant human breast lesions: down regulation of cytokeratins.  Br J Cancer. 1996;  73 1632-1638
• 10 Ferrero M. et al . Flow cytometric analysis of DNA content and keratins by using CK7, CK8, CK18, CK19, and KL1 monoclonal antibodies in benign and malignant human breast tumors.  Cytometry. 1990;  11 716-724
• 11 Harbeck N. et al . Tumour cell detection in the bone marrow of breast cancer patients at primary therapy: results of a 3-year median follow-up.  Br J Cancer. 1994;  69 566-571
• 12 Hatzfeld M, Franke W W. Pair formation and promiscuity of cytokeratins: formation in vitro of heterotypic complexes and intermediate-sized filaments by homologous and heterologous recombinations of purified polypeptides.  J Cell Biol. 1985;  101 1826-1841
• 13 Lichtner R B. et al . Coexpression of cytokeratins characteristic for myoepithelial and luminal cell lineages in rat 13762 NF mammary adenocarcinoma tumors and their spontaneous metastases.  Cancer Res. 1991;  51 5943-5950
• 14 Moll R. et al . The catalog of human cytokeratins: Pattern of expression in normal epithelial tumors and cultured cells.  Cell. 1982;  31 11-24
• 15 Moll R. Cytokeratins as markers of differentiation: expression profiles in epithelial tumors. Stuttgart; Gustav Fischer 1993
• 16 Ohnishi T, Watanabe S. The use of cytokeratin 7 and 20 in the diagnosis of primary and secondary extra-mammary Paget's disease.  Br J Dermatol. 2000;  142 234-237
• 17 Pankov R. et al . Contrasting effects of K8 and K18 on stabilizing K19 expression, cell motility and tumorigenicity in the BSp73 adenocarcinoma.  J Cell Sci. 1997;  110 965-974
• 18 Pantel K. et al . Differential expression of proliferation-associated molecules in individual micrometastatic carcinoma cells.  J Natl Cancer Inst. 1993;  85 1419-1424
• 19 Remmele W, Stegner H E. Immunhistochemischer Nachweis von Östrogenrezeptoren (Er-ICA) im Mammakarzinomgewebe, Vorschlag zur einheitlichen Bewertung des Untersuchungsbefundes.  Der Frauenarzt. 1987;  2 41-43
• 20 Reynolds C. et al . Sentinel lymph node biopsy with metastasis: can axillary dissection can be avoided in some patients with breast cancer?.  J Clin Oncol. 1999;  17 1720-1726
• 21 Schaller G. et al . Elevated keratin 18 protein expression indicates a favorable prognosis in patients with breast cancer.  Clin Cancer Res. 1996;  2 1879-1885
• 22 Schaller G. et al . Zur klinischen Bedeutung von Keratin 18 beim Mammakarzinom.  Zentralblatt Gyn. 1999;  121 126-130
• 23 Smedts F. et al . Changing patterns of keratin expression during progression of cervical intraepithelial neoplasia.  Am J Pathol. 1990;  136 657-669
• 24 Sommers C L. et al . Differentiation state and invasiveness of human breast cancer cell lines.  Breast Cancer Res Treat. 1994;  31 325-335
• 25 Stasiak P C. et al . Keratin 19: predicted amino acid sequence and broad tissue distribution suggest it evolved from keratinocyte keratins.  J Invest Dermatol. 1989;  92 707-716
• 26 Steinert P M, Roop D R. Molecular and cellular biology of intermediate filaments.  Ann Rev Biochem. 1988;  57 593-623
• 27 Su. et al . Expression of cytokeratin messenger RNA versus protein in the normal mammary gland and in breast cancer.  Hum Pathol. 1996;  27 800-806
• 28 Thompson E W. et al . Association of increased basement membrane invasiveness with absence of estrogen receptor and expression of vimentin in human breast cancer cell lines.  J Cell Physiol. 1992;  150 534-544
• 29 Tölle H G. et al . Microinjection of monoclonal antibodies specific for one intermediate filament protein in cells containing multiple keratins allow insight into the composition of particular 10 nm filaments.  Eur J Cell Biol. 1985;  38 234-244
• 30 Valles A M. et al . Acidic fibroblast growth factor is a modulator of epithelial plasticity in a rat bladder carcinoma cell line.  Proc Natl Acad Sci USA. 1990;  87 1124-1128
• 31 Wingren S. et al . S-phase determination of immunoselected cytokeratin-containing breast cancer cells improves the prediction of recurrence.  Breast Cancer Res Treat. 1994;  29 179-187