NDRG2 correlated with favorable recurrence-free survival inhibits metastasis of mouse breast cancer cells via attenuation of active TGF-β production.
N-myc downstream-regulated gene 2 (NDRG2) has been studied for its inhibitory effects against growth and metastasis of many tumor cell types. In this study, we showed NDRG2 expression was correlated with favorable recurrence-free survival of patients with breast cancer and inhibited metastasis of breast cancer cells (4T1). NDRG2 expression was examined in 189 breast carcinoma tissues and paired normal breast tissues using immunohistochemistry. Histological and clinicopathological data were correlated using Pearson's chi-square test of independence. NDRG2 expression in human breast cancer tissues was inversely associated with lymph node metastasis and pTNM stage. Furthermore, patients with breast cancer with a high level of NDRG2 expression showed favorable recurrence-free survival (P = 0.038). To study the effect of NDRG2 on metastasis in vivo, we established an NDRG2-overexpressing mouse breast cancer cell line (4T1-NDRG2) and measured the metastasis and survival of 4T1-NDRG2 tumor-bearing mice. To test whether transforming growth factor β (TGF-β)- mediated metastasis of 4T1 was inhibited by NDRG2 expression, TGF-Smad-binding element (SBE)-luciferase activity and/or measurement of active TGF-β were performed in cell or tumor tissue level. 4T1-NDRG2 cells grew gradually and showed less metastatic activity in vivo and low invasiveness in vitro. 4T1-NDRG2 cells showed lower SBE-luciferase activity and lower level of active autocrine TGF-β than 4T1-Mock did. Correctly, our data show that NDRG2 significantly suppress tumor metastasis by attenuating active autocrine TGF-β production, and the attenuation might be typically associated with the favorable recurrence-free survival of patients clinically.
Division of Applied Life Science, Gyeongsang National University, Jinju, Korea.
Sang-seok
SS
Oh
Donghyeok
D
Kim
Dong-Hee
DH
Kim
Hong Hee
HH
Chang
Kyung-Cheol
KC
Sohn
Kyo Hyun
KH
Kim
Sung Hoo
SH
Jung
Byoung Kil
BK
Lee
Joo Heon
JH
Kim
Kwang Dong
KD
Kim
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology; D045744:Cell Line, Tumor; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D051379:Mice; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000235:genetics; D011506:Proteins / Q000378:metabolism*; D012008:Recurrence; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; C466228:NDRG2 protein, human; C485172:Ndr2 protein, mouse; D011506:Proteins; D016212:Transforming Growth Factor beta; D025521:Tumor Suppressor Proteins