Tuberous sclerosis complex is an autosomal dominant disorder caused by inactivating mutations in TSC1 or TSC2 genes encoding hamartin and tuberin, respectively. TSC is a multisystem disorder exhibiting a wide range of manifestations characterized by tumour-like lesions called hamartomas, in the brain, skin, eye, heart, kidney and lung. Pulmonary lymphangioleiomyomatosis may occur in TSC patients or may be sporadic. LAM is a progressive disease characterized by alveolar smooth muscle cell proliferation, cystic destruction of lung parenchyma, and fluid filled cystic structures in axial lymphatics. From the chylous effusion of a patient affected by TSC/LAM we have isolated and characterized alfa-actin positive smooth muscle cells. These cells showed reactivity to HMB45 and CD44v6 antibodies and bear a germline TSC2 mutation in exon 21. The exposure to the chromatin remodelling agents caused tuberin expression, indicating an epigenetic alteration as second hit. Although the entire promoter was screened by pyrosequencing analysis for methylated sites, no CpG islands with methylation were found. In spite of this result, in these chylous-derived cells a large amount of non-coding DNA with closed chromatin regions was present and the inhibitory chromatin status was reversed by 5-azacytidine treatment. The proliferation of chylous-derived cells was EGF-dependent and the blockade of EGFR caused cell death as we previously reported for TSC2-/- and TSC2-/meth ASM cells. These cells displayed the ability to switch from a short nonadherent to a long adherent phase and vice versa, and they expressed characteristics of stemness In adherent cells S6 phosphorylation was high and comparable to TSC2-/- and TSC2-/meth ASM cells while it was almost absent in nonadherent cells. By DNA content analysis, western blotting and real time-PCR, in adherent status, chylous-derived cells had a high replication rate compared to control smooth muscle cells while in nonadherent status the cells underwent an extremely low rate of proliferation consistent with tumor stem cell characteristics. Carcinoma cells may migrate from primary tumours through a process of EMT depending on an inflammatory microenvironment such as interleukin expression. The chylous-derived TSC2 cells secreted high amount of IL-6 and IL-8. Moreover, both nonadherent and adherent chylous-derived TSC2 cells showed invasive properties. The evaluation of migration and invasiveness of TSC cells may be relevant to understand how to control their molecular and pathological features.
Characterization of human TSC2 cells derived from a TSC/LAM patient chylous effusion / E. Lesma, S. Ancona, V. Grande, S.M. Sirchia, E. Orpianesi, E. Chiaramonte, A.M. Di Giulio, A. Gorio. ((Intervento presentato al convegno International TSC Research Conference tenutosi a Belfast nel 2011.
|Titolo:||Characterization of human TSC2 cells derived from a TSC/LAM patient chylous effusion|
LESMA, ELENA ANNA (Primo)
ANCONA, SILVIA (Secondo)
DI GIULIO, ANNA MARIA (Penultimo)
GORIO, ALFREDO (Ultimo)
|Data di pubblicazione:||set-2011|
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
|Enti collegati al convegno:||Tuberous Sclerosis Alliance|
|Citazione:||Characterization of human TSC2 cells derived from a TSC/LAM patient chylous effusion / E. Lesma, S. Ancona, V. Grande, S.M. Sirchia, E. Orpianesi, E. Chiaramonte, A.M. Di Giulio, A. Gorio. ((Intervento presentato al convegno International TSC Research Conference tenutosi a Belfast nel 2011.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|