Gene expression profiling of primary human articular chondrocytes in high-density micromasses reveals patterns of recovery, maintenance, re- and dedifferentiation
GENE
Authors: Dehne, Tilo; Schenk, Rita; Perka, Carsten; Morawietz, Lars; Pruss, Axel; Sittinger, Michael; Kaps, Christian; Ringe, Jochen
Abstract
The high-density micromass culture has been widely applied to study chondrocyte cell physiology and pathophysiological mechanisms. Since an integrated image has not been established so far, we analyzed the phenotypic alterations of human articular chondrocytes in this model on the broad molecular level. Freshly isolated chondrocytes were assembled as micromasses and maintained up to 6 weeks in medium containing human serum. Formation of cartilaginous extracellular matrix (ECM) was evaluated by histological and immunohistochemical staining. At 0, 3 and 6 weeks, chondrocyte micromasses were subjected to gene expression analysis using oligonucleotide microarrays and real-time RT-PCR. Micromasses developed a cartilaginous ECM rich in proteoglycans and type II collagen. On gene expression level, time-dependent expression patterns was observed. The induction of genes associated with cartilage-specific ECM (COL2A1 and COL11A1) and developmental signaling (GDF5. GDF10, 1D1, 1D4 and FUR1-3) indicated redifferentiation within the first 3 weeks. The repression of genes related to stress response (HSPA1A and HSPA4), apoptotic events (HYOU1, NFKBIA and TRAF1), and degradation (MMP1, MMPIO and MMP12) suggested a recovery of chondrocytes. Constant expression of other chondrogenic (ACAN, FN1 and MGP) and hypertrophic markers (COL10A1, ALPL, PTHR1 and PTHR2) indicated a pattern of phenotypic maintenance. Simultaneously, the expression of chondrogenic growth (BMP6, TGFA, FGF1 and FGF2) and transcription factors (50X9, EGR1, HES1 and TG1F1), and other cartilage ECM-related genes (COMP and PRG4) was consistently repressed and expression of collagens related to dedifferentiation (COL1 A1 and COL3A1) was steadily induced indicating a progressing loss of cartilage phenotype. Likewise, a steady increase of genes associated with proliferation (GAS6, SERP1NF1, VEGFB and VEGFC) and apoptosis (DRAM, DPAK1, HSPB, GPX1, NGFRAP1 and 77A1) was observed. Sequence and interplay of identified expression patterns suggest that chondrocyte micromass cultures maintain a differentiated phenotype up to 3 weeks in vitro and might be useful for studying chondrocyte biology, pathophysiology and differentiation. Cultivation longer than 6 weeks leads to progressing dedifferentiation of chondrocytes that should be considered on long-term evaluations. (C) 2010 Elsevier B.V. All rights reserved.
Euphorbia tirucalli modulates gene expression in larynx squamous cell carcinoma
BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE
Authors: Franco-Salla, Gabriela Bueno; Prates, Janesly; Cardin, Laila Toniol; Dinarte dos Santos, Anemari Ramos; da Silva, Wilson Araujo, Jr.; da Cunha, Bianca Rodrigues; Tajara, Eloiza Helena; Oliani, Sonia Maria; Rodrigues-Lisoni, Flavia Cristina
Abstract
Background: Some plants had been used in the treatment of cancer and one of these has attracted scientific interest, the Euphorbia tirucalli (E. tirucalli), used in the treatment of asthma, ulcers, warts has active components with activities scientifically proven as antimutagenic, anti-inflammatory and anticancer. Methods: We evaluate the influence of the antitumoral fraction of the E. tirucalli latex in the larynx squamous cell carcinoma (Hep-2), on the morphology, cell proliferation and gene expression. The Hep-2 cells were cultivated in complete medium (MEM 10 %) and treated with E. tirucalli latex for 1, 3, 5 and 7 days. After statistically analyzing the proliferation of the tested cells, the cells were cultivated again for RNA extraction and the Rapid Subtractive Hybridization (RaSH) technique was used to identify genes with altered expression. The genes found using the RaSH technique were analyzed by Gene Ontology (GO) using Ingenuity Systems. Results: The five genes found to have differential expression were validated by real-time quantitative PCR. Though treatment with E. tirucalli latex did not change the cell morphology in comparison to control samples, but the cell growth was significantly decreased. The RaSH showed change in the expression of some genes, including ANXA1, TCEA1, NGFRAP1, ITPR1 and CD55, which are associated with inflammatory response, transcriptional regulation, apoptosis, calcium ion transport regulation and complement system, respectively. The E. tirucalli latex treatment down-regulated ITPR1 and up-regulated ANXA1 and CD55 genes, and was validated by real-time quantitative PCR. Conclusions: The data indicate the involvement of E. tirucalli latex in the altered expression of genes involved in tumorigenic processes, which could potentially be applied as a therapeutic indicator of larynx cancer.