Liver Cancer
Copyright ©The Author(s) 2002. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 15, 2002; 8(2): 233-236
Published online Apr 15, 2002. doi: 10.3748/wjg.v8.i2.233
Effects of cryopreservation and phenylacetate on biological characters of adherent LAK cells from patients with hepatocellular carcinoma
Ning Zheng, Sheng-Long Ye, Rui-Xia Sun, Yan Zhao, Zhao-You Tang
Ning Zheng, Sheng-Long Ye, Rui-Xia Sun, Yan Zhao, Zhao-You Tang, Liver Cancer Institute and Zhongshan Hospital, Fudan University, Shanghai 200032, China
Author contributions: All authors contributed equally to the work.
Supported by the National 9th Five-Year Program of China, No. 96-906-01-20
Correspondence to: Prof. Sheng-Long Ye, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China. slye@shmu.edu.cn
Telephone: +86-21-64041990-2137
Received: November 15, 2001
Revised: December 1, 2001
Accepted: December 10, 2001
Published online: April 15, 2002
Abstract

AIM: To improve the preparation of adherent lymphokine-activated killer (A-LAK) cells and to study the effects of cryopreservation and phenylacetate (PA) on biological characters of A-LAK cells.

METHODS: A-LAK cells were obtained from peripheral blood mononuclear cells (PBMCs) of the patients with hepatocellular carcinoma (HCC) by using L-phenylalanine methyl ester (PME) to deplete immunosuppressive monocytes. Proliferative activity of SMMC7721 cell line after treatment with phenylacetate (PA) was observed. A-LAK cells were treated with the supernatant of SMMC7721 cells that had been pretreated with PA. The changes of proliferation, cytotoxicity and phenotype of A-LAK cells were investigated after cryopreservation.

RESULTS: The expansion of A-LAK cells (96.79 ± 69.10 folds on Day 14) was significantly higher than that of non-adherent LAK (NA-LAK) cells (22.77 ± 13.20) as well as conventional LAK cells (4.64 ± 0.91). PA significantly suppressed the growth of SMMC7721 cells, and the inhibitor ratio was 46%. The supernatant of cultured tumor cells intensively suppressed the proliferation and cytotoxicity of A-LAK cells, but the suppressive effect of the supernatant was previously decreased after treatment with PA. Impairments in proliferation and cytotoxicity of A-LAK cells immediately after thawing of cryopreservation and recovery after reincubation with IL-2 were observed. The cytotoxicity of thawed A-LAK cells on Day 5 was significantly higher than that of fresh A-LAK before freezing (54.8% ± 10.2% vs 40.5% ± 6.4%). No significant change in the percentage of lymphocyte subsets was identified in frozen A-LAK cells as compared with that in the fresh control cells.

CONCLUSION: A-LAK cells can be simply prepared by using PME, and showed a synergistic anti-tumor effect with the combination of PA. Cryopreservation can increase the immunoactivities of A-LAK cells from the patients with hepatocellular carcinoma.

Keywords: $[Keywords]