http___medlib.mef.hr_956__1.xml
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Pećina-Šlaus, Nives and Žigmund, Martina and Kušec, Vesna and Nikuševa Martić, Tamara and Čačić, Mirjana and Šlaus, Mario (2007) E-cadherin and beta-catenin expression patterns in malignant melanoma assessed by image analysis. Journal of Cutaneous Pathology, 34 (3). Abstract BACKGROUND: We investigated the expression of E-cadherin and beta-catenin in melanoma. Both proteins are components of adherens junctions but also play signalling roles in the wnt signal transduction pathway. ----- MATERIALS AND METHODS: Seventy malignant melanomas were analysed by immunohistochemistry and evaluated by image analysis as staining density, i.e. light permeability (LP). ----- RESULTS: Comparison of mean values of relative LP for E-cadherin and beta-catenin in tumor tissue shows that levels of E-cadherin protein are significantly lower (259.67-116.23; t=22.7; p=0.000). The comparison of mean values of the relative LP of E-cadherin in melanoma to the LP in the adjacent normal skin also shows that the expression of E-cadherin in tumor is significantly lower (256.06-169.87; t=11.55, p=0.000). beta-catenin was observed in the cytoplasm in 30.6% of patients, in 24.2% in the cell membrane, in 21% in both the cytoplasm and membrane, in 1.6% in the membrane and nucleus and in 4.8% in the cytoplasm and nucleus, whereas in 17.7% of patients beta-catenin could not be observed. Patients with Clark 4 and 5 had significantly less beta-catenin than patients with Clark 2 and 3 (chi2=12.854; p=0.005). ----- CONCLUSIONS: Changes in E-cadherin and beta-catenin levels have important roles in melanoma and could be used as molecular markers of disease progression. Actions (login required) Downloads Downloads per month over past year
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Pećina-Šlaus, Nives and Nikuševa Martić, Tamara and Kokotović, Tomislav and Kušec, Vesna and Tomas, Davor and Hrašćan, Reno (2011) AXIN-1 protein expression and localization in glioblastoma. Collegium Antropologicum, 35 (Suppl.). pp. 101-6. Croatian abstract IZRAŽENOST I SMJEŠTAJ PROTEINA AKSINA U GLIOBLASTOMIMA ----- Etiologija i patogeneza tumora središnjeg živčanog sustava još uvijek je nedovoljno razjašnjena. U ovoj studiji istraživani su obrasci ekspresije proteina aksina, izuzetno važne molekularne komponente signalnog puta Wnt, u 42 uzorka glioblastoma čovjeka. Imunohistokemijskom metodom i image analizom utvrđena je jačina ekspresije i lokalizacija proteina u stanicama. Smanjena ekspresija ovog tumor supresorskog proteina uočena je u 31% analiziranih tumora usporedbom s razinom ekspresije aksina u normalnom tkivu mozga. U 69% glioblastoma aksin je pronađen u citoplazmi, u 21,4% u jezgri i citoplazmi, dok je u 9,5% glioblastoma lokalizacija bila isključivo u jezgrama. Srednje vrijednosti relativne ekspresije proteina aksina dobivene image analizom pokazuju da je najveća relativna količina aksina izmjerena kada je protein lokaliziran u jezgri, a najmanja relativna količina aksina kada je lokaliziran u citoplazmi. Rezultati istraživanja aksina u glioblastomima na unutarstaničnoj razini pokazuju da je izraženost aksina i njegova prostorna regulacija vrlo dinamičan proces. Unatoč produbljivanju spoznaja o biologiji i genetici glijalnih tumora, saznanja o prognostičkim parametrima za glioblastom još uvijek nisu dostatna. Naši rezultati o razini izraženosti proteina aksina zasigurno će doprinijeti boljem razumijevanju molekularnog profila glioblastoma, te ponuditi potencijalne prognostičke značajke. English abstract The etiology and pathogenesis of tumors of the central nervous system are still inadequately explained. In the present study the expression patterns of a critical molecular component of wnt signaling pathway – axin 1 was investigated in 42 patients with glioblastoma, the most aggressive form of glial tumors. Immunostaining and image analysis revealed the quantity and localization of the protein. Downregulation of this tumor suppressor expression was observed in 31% of tumors when compared to the levels of axin in healthy brain tissues. Axin was observed in the cytoplasm in 69% of glioblastoma samples, in 21.4% in both the cytoplasm and nucleus and 9.5% had expression solely in the nucleus. Mean values of relative axin’s expression obtained by image analysis showed that the highest relative quantity of axin was measured when the protein was in the nucleus and the lowest relative quantity of axin when the protein was localized in the cytoplasm. Investigation on axin’s existence at the subcellular level in glioblastomas suggests that axin’s expression and spatial regulation is a dynamic process. Despite increasing knowledge on glioma biology and genetics, the prognostic tools for glioblastoma still need improvement. Our findings on expression of axin 1 may contribute to better understanding of glioblastoma molecular profile. Actions (login required)