BACKGROUND: Recent data indicate that gastroenteropancreatic neuroendocrine tumours (GEP-NETs) have a hypomethylated long interspersed element (LINE1) promoter. To answer the question, of whether LINE1 may be of value in assessing the malignant potential of GEP-NETs, we analysed LINE1 methylation in different organs. MATERIALS AND METHODS: A total of 58 GEP-NETs of gastric (n=14), pancreatic (n=15), small intestine (n=17), appendix (n=8), colorectal (n=4) and non-neoplastic tissues were analysed using DNA isolation, bisulphite-treatment and pyrosequencing. RESULTS: LINE1 hypomethylation was detected in 50% of gastric, 100% pancreatic, 82% small intestine, 87.5% appendix and 100% colorectal NETs. G1 (p<0.001) and G2 (p<0.05) colorectal, and G1 (p<0.001) and G2 (p<0.001) pancreatic NETs exhibited significant LINE1 hypomethylation compared with non-neoplastic tissues. Higher rates of LINE1 hypomethylation in G2 pancreatic NETs than in G1 NETs (p<0.05) were observed. NETs exhibited a significantly lower frequency of hypomethylation in cases with lymph node metastases (p<0.05). CONCLUSION: LINE1 hypomethylation may serve as a marker of tumour grade and lymph node metastasis.
BACKGROUND: Recent data indicate that gastroenteropancreatic neuroendocrine tumours (GEP-NETs) have a hypomethylated long interspersed element (LINE1) promoter. To answer the question, of whether LINE1 may be of value in assessing the malignant potential of GEP-NETs, we analysed LINE1 methylation in different organs. MATERIALS AND METHODS: A total of 58 GEP-NETs of gastric (n=14), pancreatic (n=15), small intestine (n=17), appendix (n=8), colorectal (n=4) and non-neoplastic tissues were analysed using DNA isolation, bisulphite-treatment and pyrosequencing. RESULTS: LINE1 hypomethylation was detected in 50% of gastric, 100% pancreatic, 82% small intestine, 87.5% appendix and 100% colorectal NETs. G1 (p<0.001) and G2 (p<0.05) colorectal, and G1 (p<0.001) and G2 (p<0.001) pancreatic NETs exhibited significant LINE1 hypomethylation compared with non-neoplastic tissues. Higher rates of LINE1 hypomethylation in G2 pancreatic NETs than in G1 NETs (p<0.05) were observed. NETs exhibited a significantly lower frequency of hypomethylation in cases with lymph node metastases (p<0.05). CONCLUSION: LINE1 hypomethylation may serve as a marker of tumour grade and lymph node metastasis.
Authors: Carrie V Breton; Carmen J Marsit; Elaine Faustman; Kari Nadeau; Jaclyn M Goodrich; Dana C Dolinoy; Julie Herbstman; Nina Holland; Janine M LaSalle; Rebecca Schmidt; Paul Yousefi; Frederica Perera; Bonnie R Joubert; Joseph Wiemels; Michele Taylor; Ivana V Yang; Rui Chen; Kinjal M Hew; Deborah M Hussey Freeland; Rachel Miller; Susan K Murphy Journal: Environ Health Perspect Date: 2017-03-31 Impact factor: 9.031
Authors: R F H Walter; P Rozynek; S Casjens; R Werner; F D Mairinger; E J M Speel; A Zur Hausen; S Meier; J Wohlschlaeger; D Theegarten; T Behrens; K W Schmid; T Brüning; G Johnen Journal: PLoS One Date: 2018-05-31 Impact factor: 3.240
Authors: K G Samsom; L M van Veenendaal; G D Valk; M R Vriens; M E T Tesselaar; J G van den Berg Journal: Endocr Connect Date: 2019-07 Impact factor: 3.335
Authors: Rose K Lai; Yanwen Chen; Xiaowei Guan; Darryl Nousome; Charu Sharma; Peter Canoll; Jeffrey Bruce; Andrew E Sloan; Etty Cortes; Jean-Paul Vonsattel; Tao Su; Lissette Delgado-Cruzata; Irina Gurvich; Regina M Santella; Quinn Ostrom; Annette Lee; Peter Gregersen; Jill Barnholtz-Sloan Journal: PLoS One Date: 2014-02-21 Impact factor: 3.240