Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Oct 14, 2012; 18(38): 5369-5376
Published online Oct 14, 2012. doi: 10.3748/wjg.v18.i38.5369
Axl glycosylation mediates tumor cell proliferation, invasion and lymphatic metastasis in murine hepatocellular carcinoma
Ji Li, Li Jia, Zhen-Hai Ma, Qiu-Hong Ma, Xiao-Hong Yang, Yong-Fu Zhao
Ji Li, Zhen-Hai Ma, Xiao-Hong Yang, Yong-Fu Zhao, Department of General Surgery, the Second Affiliated Hospital of Dalian Medical University, Dalian 116027, Liaoning Province, China
Li Jia, Qiu-Hong Ma, College of Laboratory Medicine, Dalian Medical University, Dalian 116044, Liaoning Province, China
Author contributions: Li J performed the whole experiment, wrote the manuscript; Zhao YF designed the experiment, provided financial support, conducted the whole study; Jia L, Ma ZH, Ma QH and Yang XH participated in the study.
Supported by Creating Team Item of Liaoning Province, No. 2008T033; the Technological Natural Fund Item of Liaoning Province, China, No. 20092164
Correspondence to: Yong-Fu Zhao, Professor, Department of General Surgery, the Second Affiliated Hospital of Dalian Medical University, 465 Zhongshan Road, Dalian 116027, Liaoning Province, China. zyf0386@sina.com
Telephone: +86-411-84671291 Fax: +86-411-84672130
Received: January 29, 2012
Revised: May 30, 2012
Accepted: June 8, 2012
Published online: October 14, 2012
Abstract

AIM: To investigate the effects of Axl deglycosylation on tumor lymphatic metastases in mouse hepatocellular carcinoma cell lines.

METHODS: Western blotting was used to analyze the expression profile of Axl glycoprotein in mouse hepatocellular carcinoma cell line Hca-F treated with tunicamycin and PNGase F 3-(4,5)-dimethylthiazol(-zyl)-3,5-diphenyltetrazolium bromide (MTT) assay, extracellular matrix (ECM) invasion assay (in vitro) and tumor metastasis assay (in vivo) were utilized to evaluate the effect of Axl deglycosylation on the Hca-F cell proliferation, invasion and lymphatic metastasis.

RESULTS: Tunicamycin and PNGase F treatment markedly inhibited Axl glycoprotein synthesis and expression, proliferation, invasion, and lymphatic metastasis both in vitro and in vivo. In the MTT assay, proliferation was apparent in untreated Hca-F cells compared with treated Hca-F cells. In the ECM invasion assay (in vitro), treated cells passed through the ECMatrix gel in significantly smaller numbers than untreated cells (tunicamycin 5 μg/mL: 68 ± 8 vs 80 ± 9, P = 0.0222; 10 μg/mL: 50 ± 6 vs 80 ± 9, P = 0.0003; 20 μg/mL: 41 ± 4 vs 80 ± 9, P = 0.0001); (PNGase F 8 h: 66 ± 7 vs 82 ± 8, P = 0.0098; 16 h: 49 ± 4 vs 82 ± 8, P = 0.0001; 24 h: 34 ± 3 vs 82 ± 8, P = 0.0001). In the tumor metastasis assay (in vivo), average lymph node weights of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 0.84 ± 0.21 g vs 0.72 ± 0.19 g, P = 0.3237; 10 μg/mL: 0.84 ± 0.21 g vs 0.54 ± 0.11 g, P = 0.0113; 20 μg/mL: 0.84 ± 0.21 g vs 0.42 ± 0.06 g, P = 0.0008); (PNGase F 8 h: 0.79 ± 0.15 g vs 0.63 ± 0.13 g, P = 0.0766; 16 h: 0.79 ± 0.15 g vs 0.49 ± 0.10 g, P = 0.0022; 24 h: 0.79 ± 0.15 g vs 0.39 ± 0.05 g, P = 0.0001). Also, average lymph node volumes of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 815 ± 61 mm3vs 680 ± 59 mm3, P = 0.0613; 10 μg/mL: 815 ± 61 mm3vs 580 ± 29 mm3, P = 0.0001; 20 μg/mL: 815 ± 61 mm3vs 395 ± 12 mm3, P = 0.0001); (PNGase F 8 h: 670 ± 56 mm3vs 581 ± 48 mm3, P = 0.0532; 16 h: 670 ± 56 mm3vs 412 ± 22 mm3, P = 0.0001; 24 h: 670 ± 56 mm3vs 323 ± 11 mm3, P = 0.0001).

CONCLUSION: Alteration of Axl glycosylation can attenuate neoplastic lymphatic metastasis. Axl N-glycans may be a universal target for chemotherapy.

Keywords: Axl; Glycosylation; Hepatocellular carcinoma; Lymphatic metastasis