Abstract
Approximately two-thirds of patients with neuroblastoma are found to have metastatic disease at time of diagnosis with frequent skeletal, lymph node, central nervous system, and liver involvement. Using a serial in vivo splenic injection model, we have isolated an aggressive subclone (BE(2)-C/LM2) from MYCN-amplified neuroblastomas that demonstrate an enhanced propensity to develop metastatic liver lesions. BE(2)-C/LM2 subclone cells demonstrate increased adherent, soft agar colony and tumorsphere growth in vitro. Components of the tumor microenvironment regulate cancer progression, via networks of cytokines and growth factors. Cytokine array analysis identified increased TIMP-1 in the plasma of mice injected with BE(2)-C/LM2 subclone cells, leading us to hypothesize that TIMP-1 may play a role in our observed prometastatic phenotype. Immunoblotting and ELISA demonstrated enhanced endogenous TIMP-1 expression in our isolated neuroblastoma subclone. Silencing endogenous TIMP-1 successfully blocked in vitro proliferation, soft agar colony formation and tumorsphere formation by BE(2)-C/LM2 cells. Stable RNA interference of endogenous TIMP-1 failed to reverse the prometastatic phenotype of our BE(2)-C/LM2 subclone in our liver metastasis model, suggesting that endogenous TIMP-1 levels may not be an essential component of this in vivo behavior. Notably, tissue microarray analysis and Kaplan-Meier by gene expression demonstrates that elevated TIMP-1 expression is correlated with increased disease relapse and mortality in patients with neuroblastoma. Taken together, our study identifies TIMP-1 as a novel soluble factor that is associated with a prometastatic phenotype in our in vivo model and adverse outcomes in patients with neuroblastoma.
Highlights
Neuroblastoma is the most common extra-cranial solid tumor in children, originating from the neuralcrest elements of the sympathoadrenal axis [1]
Cytokine array analysis identified increased tissue inhibitor of metalloproteinases (TIMP)-1 in the plasma of mice injected with BE(2)-C/LM2 subclone cells, leading us to hypothesize that TIMP-1 may play a role in our observed prometastatic phenotype
We proposed that serial in vivo selection in our splenic injection model would isolate a subclone of neuroblastoma capable of eliciting enhanced liver metastasis burden
Summary
Neuroblastoma is the most common extra-cranial solid tumor in children, originating from the neuralcrest elements of the sympathoadrenal axis [1]. Despite advances in multi-modality therapy, survival rates for advanced-stage disease remain poor at 30-50% for children with high-risk disease [2]. Of those children www.impactjournals.com/oncotarget with high-risk neuroblastoma who achieve remission with induction therapy, half will relapse, most commonly with evidence of distant metastasis to the skeleton, bone marrow, central nervous system, or liver. Identifying growth factors/cytokines that mediate tumor progression/metastasis and can be readily measured in plasma has the potential to: 1) identify targetable pathways for therapeutic intervention of high-risk tumor, 2) risk stratify patients at time of initial diagnosis into more aggressive or conservative treatment strategies, and 3) surveil patients for evidence of disease recurrence
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call