Author/Editor		Zajc, Irena; Bervar, Aleš; Lah, Tamara T
Title		Cysteine cathepsins, stefins and extracellular matrix degradation during invasion of transformed human breast cell lines
Translated title		Cisteinski katepsini, stefini in razgradnja izvenceličnega matriksa med invazijo človeških transformiranih celičnih linij raka dojke
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 40, št. 4
Publication year		2006
Volume		str. 259-71
Language		eng
Abstract		Background. Human breast cellular model, comprising four cell lines originating from spontaneously immortalized human breast epithelial MCF10A cell line, its c-Ha-ras transfectant, MCF10AT, and two tumourigenic derivatives, cultured from two sequential mouse xenographs, MCF10AT-Ca1a and MCF10AT-Ca1d, were used to compare the relative protein concentration of cathepsins and stefins in single cells. Methods. The relative protein concentration of cathepsins and stefins in single cells was analysed by confocal microscopy, and compared to their protein expression in cell homogenates. Results. The most invasive, MCF10AT cell line contained several fold higher protein concentration of cathepsin B and increased levels of stefins, but similar levels of cathepsin L, compared with the parental MCF10A cells. This was associated with five fold higher endocytosis of Matrigel-DQ-collagen IV (DQC) and a simultaneous increase in signal overlap between DQC and cathepsin L as well as DQC and stefin B, but a decrease in that of DQC and cathepsin B overlap in the MCF10AT cells. Simultaneously, increased signal overlaps between both cathepsins and between cathepsins-stefins pairs, were observed in this cell line. Conclusions. These results suggest that the increased collagen endocytosis and degradation in the invasive phenotype significantly affect also the subcellular localization of cysteine cathepsins and stefins. Based on these and the reports of other authors, we hypothesize that the intracellular degradation may also be assoeiated with cathepsin L, whereas cathepsin B in the ras transformed breast cells is involved in both, the intracellular and pericellular degradation of extracellular matrix during cell migration and invasion.
Summary		Izhodišča. Celični model človeškega raka dojke, ki je vseboval štiri celične linije, osnovno MCF10A, spontano imortalizirano linijo epitelija človeške dojke, MCF10AT, ki je nastala s c-Ha-ras transfekcijo osnovne linije ter dve tumorigeni liniji, MCF10AT-Ca1a in MCF10AT-Ca1d, pridobljeni iz zaporednih vsadkov MCF10AT v miškah, smo uporabili za primerjavo relativne količine katepsinov in stefinov v posameznih celicah. Metode. Relativne količine katepsinov in stefinov v posameznih celicah smo ocenili s konfokalno mikroskopijo in z merjenjem proteinske koncentracije v celičnih homogenatih. Rezultati. Najbolj invazivne MCF10AT celice so izražale nekajkrat več katepsina B in več stefinov, vsebovale pa so podobne koncentacije katepsina L kot osnovna, MCF10A celična linija. To je bilo povezano s petkrat višjo endocitozo substrata - Matrigela z DQ kolagenom IV (DQC) - in s hkratnim povišanjem prekrivanja signalov med DQC in katepsinom L ter DQC in stefinom B, a z manjšim prekrivanjem signalov med DQC in katepsinom B v MCF10AT celicah. Pri teh celicah smo opazili tudi znatno večje prekrivanje signalov med obema katepsinoma in med pari katepsinov in stefinov. Zaključki. Ti rezultati kažejo, da pride pri invazivnem celičnem fenotipu do večje endocitoze in razgradnje kolagena ter istočasne spremembe v lokalizaciji katepsinov in stefinov v celici. Glede na to in podatke drugih avtorjev se zdi, da je znotrajcelična razgradnja bolj povezana s katepsinom L, medtem ko katepsin B v večji meri sodeluje pri pericelularni razgradnji medceličnega matriksa tekom celične migracije in invazije.
Descriptors		BREAST NEOPLASMS TUMOR CELLS, CULTURED NEOPLASM INVASIVENESS CATHEPSINS EXTRACELLULAR MATRIX ENZYME-LINKED IMMUNOSORBENT ASSAY MICROSCOPY, CONFOCAL