AIM:TO investigate whether CTL vaccine therapy issuitable for primary hepatocellular carcinoma(HCC)from the viewpoint of HLA class Ⅰ antigens expression.METHODS:The immunocytochemistry,image analysis,flow cytometry,and labeled streptavidin biotin(LSAB)method of immunohistochemistry were appliedrespectively to study 4 HCC call lines(e.g.Alexander,HepG2,SMMC-7721,and QGY-7703)cultured in vitroand 6 frozen tissue specimens of HCC.RESULTS:The positive control cell line Raji had verystrong positive staining.Most mitotic and nonmitoticcells of the 4 HCC cell lines had various intensity ofHLA class Ⅰ antigens expression.The negative controlcell K562 and the control slides of all the cell lines hadno positive staining.In the 6 HCC specimensimmunohistochemically studied,histological normalhepatocytes had no or very weak positive staining andthe liver sinus had very strong positive staining.MostHCC cells in the sections from the 6 HCC specimenshad strong positive HLA class Ⅰ antigens staining.Thepositive staining was located in the cytoplasm,theperinuclear area,and at the call membrane of the livercancer calls.Flow cytemetry also revealed that Raji andthose 4 HCC cell lines had strong HLA class Ⅰ antigensexpression,which was confirmed quantitatively by theimage analysis.It showed that the objective grayscalevalues of Raji and those 4 HCC cell lines weresignificanUy different from that of K562(Raji 114.04±10.94,Alexander 165.97±5.35,HepG2 167.02±12.60,QGY-7703 161.46±7.13,SMMC-7721 165.93±5.21,KS62 244.89±4.60,P<0.01).Significant differenceswere also found between Raji and the 4 HCC call lines.CONCLUSION:HCC cells express HLA class Ⅰ antigensstrongly.From this point of view,the active specificimmunetherapy of CTL vaccine is suitable andpracticable for HCC. AIM:TO investigate whether CTL vaccine therapy is suitable for primary hepatocellular carcinoma(HCC) from the viewpoint of HLA class I antigens expression.METHODS:The immunocytochemistry,image analysis,flow cytometry,and labeled streptavidin biotin(LSAB) method of immunohistochemistry were appliedrespectively to Study 4 HCC call lines(egAlexander,HepG2,SMMC-7721,and QGY-7703)cultured in vitroand 6 frozen tissue specimens of HCC.RESULTS:The positive control cell line Raji had very strong positive staining.Most mitotic and nonmitotic cells of the 4 HCC cell lines had various intensity of HLA class I antigens expression.The negative controlcell K562 and the control slides of all the cell lines hadno positive staining.In the 6 HCC specimensimmunohistochemically studied,histological normalhepatocytes had no or very weak positive staining andthe liver sinus had very Strongly positive staining.MostHCC cells in the sections from the 6 HCC specimenshad strongly positive HLA class I antigens stain ing.The positive staining was located in the cytoplasm,theperinuclear area,and at the call membrane of the livercancer calls.Flow cytemetry also revealed that Raji andthose 4 HCC cell lines had strong HLA class I antigensexpression,which was confirmed quantitatively by the image analysis.It Showed that the objective grayscale values ​​of Raji and those 4 HCC cell lines weresignificant Uy different from that of K562 (Raji 114.04±10.94, Alexander 165.97±5.35, HepG2 167.02±12.60, QGY-7703 161.46±7.13, SMMC-7721 165.93±5.21, KS62 244.89±4.60, P<0.01). Significant differences were also found between Raji and the 4 HCC call lines. CONCLUSION: HCC cells express HLA class I antigens. From this point of view, the active specificimmune therapy of CTL vaccine is suitable and practicable for HCC.