Cellular Senescence is a Common Characteristic Shared by Preneoplasic and Osteo-Arthritic Tissue~!2009-12-06~!2010-01-18~!2010-02-11~!

Abstract

Objective:This study aims at highlighting the common signature between cartilaginous tissue in osteoarthritis (OA) and preneoplasic tissues preceding neoplasia and tumour formation and, second, focusing on the molecular mechanisms at the aetiology of both pathologies.Results:Because age is the highest risk factor common for both OA and cancer development, it is tempting to compare the molecular mechanisms occurring at the onset of OA and preneoplasic lesions. Indeed, cellular senescence seems to be a common characteristic. Cellular senescence represents a natural barrier to suppress the unscheduled proliferation of damaged cells acting as a strong tumour suppressor pathway and in OA, it also occurs prematurely in chondrocytes. In this study, we review a number of molecular factors associated with the senescent phenotype.Conclusion:Whereas accumulation of senescent cells in preneoplasic-like lesions leads to tissue degeneration and potentially tumour development; in OA, senescent cells accumulate in a slowly proliferative tissue. This is likely contributing at reducing the risk of cell transformation.

Chondrogenic Differentiation of Mesenchymal Stem Cells: Challenges and Unfulfilled Expectations

“…9,25,[29][30][31][32][33] Joint articular cartilage does not normally undergo hypertrophy, except under severe pathological conditions. [34][35][36][37][38][39][40] In fact, this sequence of events and the morphology of the resulting cartilage are more reminiscent of the early phases of endochondral ossification as seen in the skeletal development or fracture repair, where it is a prelude to programmed cell death and mineralization. 9,25,[29][30][31][32][33]38,[41][42][43] Completing the terminal differentiation motif, mineralization of the cartilage ECM has been noted in in vitro aggregate cultures, 43 and Pelttari et al showed that, after ectopic implantation in SCID mice, MSC-derived cartilage aggregates mineralize, vascularize, and form ossicles, further supporting an intrinsic endochondral bone formation behavior of MSCs.…”

Effects of Bauhinia championii (Benth.) Benth. polysaccharides on the proliferation and cell cycle of chondrocytes

“…Adult articular cartilage consists of a relatively sparse population of non-proliferating chondrocytes which produce a large amount of extracellular matrix (ECM), mainly composed of two major types of macromolecules, collagens (types II, IX and XI) and proteoglycans. Chondrocytes are responsible for tissue homeostasis, including the synthesis and degradation of ECM components (3). Therefore, chondrocyte proliferation is important in maintaining cellular function.…”

La sénescence cellulaire

“…Cette sénescence prématurée serait due aux stress mécaniques répétés et à l'accumulation des radicaux libres, affectant l'homéostasie du tissu et engendrant une dégradation progressive du cartilage [43]. Pour conclure, il faut signaler que si ces liens complexes entre sénes-cence, cancer et vieillissement ont été identifiés expérimentale-ment dans de nombreux modèles animaux, ils demeurent difficiles à démontrer formellement chez l'homme.…”