Osteopontin regulates epithelial mesenchymal transition-associated growth of hepatocellular cancer in a mouse xenograft model Journal Article

Authors: Bhattacharya, S. D.; Mi, Z.; Kim, V. M.; Guo, H.; Talbot, L. J.; Kuo, P. C.
Article Title: Osteopontin regulates epithelial mesenchymal transition-associated growth of hepatocellular cancer in a mouse xenograft model
Abstract: OBJECTIVE: To determine the efficacy of osteopontin (OPN) targeting in hepatocellular cancer (HCC). SUMMARY/BACKGROUND: OPN is associated with HCC growth and metastasis and represents a unique therapeutic target. METHODS: OPN and epithelial-mesenchymal transition (EMT) markers, alpha-smooth muscle actin (SMA), vimentin, and tenascin-c, were measured in archived human HCC tissues from metastatic (n = 4) and nonmetastatic (n = 4) settings. Additional studies utilized human Sk-Hep-1 (high OPN expression) and Hep3b (low OPN expression) HCC cells. An RNA aptamer (APT) that avidly binds (Kd = 18 nM; t1/2 = 7 hours) and ablates OPN binding was developed. Adhesion, migration/invasion, and EMT markers were determined with APT or a mutant control aptamer (Mu-APT). RFP-Luc-Sk-Hep-1 were implanted into NOD-scid mice livers and followed by using bioluminescence imaging. After verification of tumor growth, at week 3, APT (0.5 mg/kg; n = 4) or Mu-APT (0.5 mg/kg; n = 4) was injected q48h. When mice were killed at week 8, tumor cells were reisolated and assayed for EMT markers. RESULTS: OPN and EMT markers were significantly increased in the metastatic cohort. APT inhibited Sk-Hep-1 adhesion and migration/invasion by 5- and 4-fold, respectively. APT significantly decreased EMT protein markers, SMA, vimentin, and tenascin-c. In contrast, APT did not alter Hep3B adhesion, or migration/invasion. EMT markers were slightly decreased. In the in vivo model, at weeks 6 to 8, APT inhibited HCC growth by more than 10-fold. SMA, vimentin, and tenascin-c mRNAs were decreased by 60%, 40%, and 49%, respectively, in RFP-positive Sk-Hep-1 recovered by fluorescence-activated cell sorting (P 0.04 vs Mu-APT for all). CONCLUSIONS: APT targeting of OPN significantly decreases EMT and tumor growth of HCC.
Keywords: Animals; Humans; Mice; Adult; Aptamers, Nucleotide; Blotting, Western; Carcinoma, Hepatocellular/metabolism/pathology; Cell Line, Tumor; Epithelial-Mesenchymal Transition/physiology; Liver Neoplasms/metabolism/pathology; Liver Neoplasms, Experimental/metabolism/pathology; Middle Aged; Neoplasm Metastasis; Neoplasm Transplantation; Osteopontin/metabolism; Real-Time Polymerase Chain Reaction; SELEX Aptamer Technique; Tumor Markers, Biological/metabolism; Surgery
Journal Title: Annals of Surgery
Volume: 255
Issue: 2
ISSN: 1528-1140; 0003-4932
Publisher: Unknown  
Journal Place: United States
Date Published: 2012
Start Page: 319
End Page: 325
Language: eng
Notes: LR: 20131015; GR: R01 GM065113/GM/NIGMS NIH HHS/United States; GR: R01 GM065113/GM/NIGMS NIH HHS/United States; GR: R01 GM065113-05A2/GM/NIGMS NIH HHS/United States; GR: T32 CA093245/CA/NCI NIH HHS/United States; GR: T32 GM069331/GM/NIGMS NIH HHS/United States; JID: 0372354; 0 (Aptamers, Nucleotide); 0 (Tumor Markers, Biological); 106441-73-0 (Osteopontin); NIHMS340032; OID: NLM: NIHMS340032; OID: NLM: PMC3725267; ppublish