BACKGROUND: Ewing sarcoma (ES) is the second most common solid bone and soft tissue malignancy in children and young adults with low cure rates indicating the need to identify further prognostic markers. The importance of methylation in the inactivation of key tumor suppressor genes including RASSF1A has begun to be appreciated in context of cancer development, prognosis and therapy. However there is lack of similar broad based studies in ES. The objective of this study was to analyze RASSF1A methylation and assess its clinical significance in ES. PROCEDURE: The methylation of RASSF1A was determined 31 ES tumor samples and 4 ES cell lines. ES cell lines were also treated with demethylating agent 5-aza-2'-deoxycytidine to ascertain its effect on methylation. RASSF1A expression was studied in 12 ES tumors. The association between RASSF1A methylation, clinical parameters and outcome was also analyzed. RESULTS: Methylation of RASSF1A was observed in 21/31 (68%) tumors and in 3/4 ES cell lines. A significant correlation of methylation to reduced expression of RASSF1A was observed in 12 ES tumors analyzed (P = 0.0013) and in all cell lines. ES patients with methylated RASSF1A had worse prognosis compared to the unmethylated group (P = 0.049). Treatment with 5-aza-2'-deoxycytidine resulted in the re-expression of the unmethylated form of RASSF1A in two ES cell lines. CONCLUSION: RASSF1A is frequently methylated in ES.
BACKGROUND:Ewing sarcoma (ES) is the second most common solid bone and soft tissue malignancy in children and young adults with low cure rates indicating the need to identify further prognostic markers. The importance of methylation in the inactivation of key tumor suppressor genes including RASSF1A has begun to be appreciated in context of cancer development, prognosis and therapy. However there is lack of similar broad based studies in ES. The objective of this study was to analyze RASSF1A methylation and assess its clinical significance in ES. PROCEDURE: The methylation of RASSF1A was determined 31 ES tumor samples and 4 ES cell lines. ES cell lines were also treated with demethylating agent 5-aza-2'-deoxycytidine to ascertain its effect on methylation. RASSF1A expression was studied in 12 ES tumors. The association between RASSF1A methylation, clinical parameters and outcome was also analyzed. RESULTS: Methylation of RASSF1A was observed in 21/31 (68%) tumors and in 3/4 ES cell lines. A significant correlation of methylation to reduced expression of RASSF1A was observed in 12 ES tumors analyzed (P = 0.0013) and in all cell lines. ES patients with methylated RASSF1A had worse prognosis compared to the unmethylated group (P = 0.049). Treatment with 5-aza-2'-deoxycytidine resulted in the re-expression of the unmethylated form of RASSF1A in two ES cell lines. CONCLUSION:RASSF1A is frequently methylated in ES.
Authors: Michele Dowless; Caitlin D Lowery; Terry Shackleford; Matthew Renschler; Jennifer Stephens; Robert Flack; Wayne Blosser; Simone Gupta; Julie Stewart; Yue Webster; Jack Dempsey; Alle B VanWye; Philip Ebert; Philip Iversen; Jonathan B Olsen; Xueqian Gong; Sean Buchanan; Peter Houghton; Louis Stancato Journal: Clin Cancer Res Date: 2018-08-21 Impact factor: 12.531
Authors: Nikul Patel; Jennifer Black; Xi Chen; A Mario Marcondes; William M Grady; Elizabeth R Lawlor; Scott C Borinstein Journal: Sarcoma Date: 2012-09-12
Authors: Lieke M J van Zogchel; Nathalie S M Lak; Onno J H M Verhagen; Ahmed Tissoudali; Mohammed Gussmalla Nuru; Nina U Gelineau; Lily Zappeij-Kannengieter; Ahmad Javadi; Eline A M Zijtregtop; Johannes H M Merks; Marry van den Heuvel-Eibrink; Antoinette Y N Schouten-van Meeteren; Janine Stutterheim; C Ellen van der Schoot; Godelieve A M Tytgat Journal: JCO Precis Oncol Date: 2021-11-17