[Correlation between interleukin-28B genetic polymorphisms and primary hepatocellular carcinoma].

OBJECTIVE: To explore the correlation between single nucleotide polymorphisms (SNPs) of interleukin-28B (IL-28B) gene and the susceptibility to primary hepatocellular carcinoma (HCC). METHODS: A total of 300 histologically confirmed HCC cases (from November 2001 to April 2010) and 310 healthy controls with no history of chronic hepatitis B or hepatocellular carcinoma (2009-2010) were selected from a hospital in Guilin and a hospital in Beijing for this case-control study.139 HCC patients in the case group had complete clinical tracking data. All the subjects were Han Chinese, with no age or gender restrictions.2 ml peripheral blood samples were drawn from each subject with informed consent. SNP of rs12972991, rs4803223, rs8099917 and rs12979860 four loci in IL-28B gene were analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). RESULTS: The frequencies of C allele at rs12972991, G allele at rs8099917 and G allele at rs4803223 were 6.7% (40/598), 7.9% (47/598) and 10.0% (59/588) respectively in case group; all higher than the corresponding frequencies in control group, separately 2.9% (18/618), 4.1% (25/616) and 3.6% (21/608). The differences were statistically significant (χ2=9.542, 7.858, 20.736, P values all<0.05). The above alleles could increase the risk of HCC, and the OR (95%CI) values were separately 1.67 (1.13-2.46), 1.49 (1.08-2.06) and 2.91 (1.79-4.72). The genotype frequencies of AC+CC at rs12972991, GT+GG at rs8099917, GA+GG at rs4803223 were 13.0% (39/299), 14.7% (44/299) and 19.0% (56/296) respectively in case group; while the frequencies were lower in control group, separately 5.8% (18/309), 8.1% (25/308) and 6.6% (20/304). The differences were statistically significant (χ2=9.319, 6.557, 20.948, P values all<0.05). These genotypes may increase the risk of HCC, and the adjusted OR (95%CI) values were 2.24 (1.31-3.83), 1.81 (1.14-2.88) and 2.90 (1.78-4.70), respectively. The stratified analysis of the clinical data indicated that the frequency of genotype GA+GG at rs4803223 was 50.0% (13/26) in patients of tumor thrombosis in portal vein (TTPV), higher than the frequency of genotype AA (21.1%, 23/109). The difference was statistically significant (χ2=8.965, P=0.003). CONCLUSION: The results suggested that IL-28B gene polymorphisms was correlated to the susceptibility to HCC in Chinese Han ethnic population. Among them, GA + GG genotype at rs4803223 could increase the risk of TTPV in HCC patients.

[The inhibitory effect of RNA interference on STAT3 expression in liver cancer cell line SMMC7721].

AIM: To investigate the chemosensitivity small interfering RNA (siRNA) on liver cancer cell line SMMC7721. METHODS: The siRNA sequences design based on signal transducers and activators of transcription 3 (STAT3) gene, siRNA were transfected into SMMC7721 cells through liposome lipofectamine(TM); 2000. The expression inhibition of STAT3 gene in SMMC7721 cells was measured by real-time relative quantitative PCR. The cells growth inhibition rate were measured by MTT colorimetry after 10 µmol/L 5-fluorouracil (5-Fu) action. RESULTS: The siRNA expression vector to aim directly at STAT3 gene was constructed successfully. The result of real-time PCR revealed that specificity siRNA were transfected into SMMC7721 cells could inhibit the expression of STAT3 gene. STAT3 gene in SMMC7721 cells were specialty and effectually inhibit the expression by RNA interference (RNAi). MTT colorimetry detection result revealed that SMMC7721 cells inhibition rate significantly increasing after siRNA action. CONCLUSION: The siRNA expression vector can active inhibit expression of STAT3 gene in SMMC7721 cells, enhance its sensitivity to chemotherapeutics 5-Fu, to provide experiment based on for the biological therapy of tumor.

Regulatory T cell depletion enhances tumor specific CD8 T-cell responses, elicited by tumor antigen NY-ESO-1b in hepatocellular carcinoma patients, in vitro.

Immunotherapy in hepatocellular carcinoma based on one or a few tumor specific antigens have shown limited antitumor efficacy. As a major suppressive factor in tumor immune response, better understanding of the role of regulatory T cells (Tregs) in hepatocellular carcinoma might be important for design of future immunotherapy-based clinical protocols. Tregs from 49 HCC patients and 40 controls were identified by flow cytometric analysis for the phenotype. Functional studies were performed by analyzing their inhibition to immune responses. Finally investigating whether elimination of Tregs was capable of enhancing the immunostimulatory efficacy of NY-ESO-1b peptides. In HCC peripheral blood and tumor-infiltrating lymphocytes, we found increased numbers of Tregs, which expressed high levels of HLA-DR, GITR and CD103. The prevalence of Tregs increased with during progressive stages in HCC patients. Moreover, the elimination of Treg cells followed by stimulating with NY-ESO-1b peptide significantly improved the anti-tumor cytotoxic T lymphocytes responses in HCC patients compared with stimulating with NY-ESO-1b peptide alone. The immune response efficiency increased from 37.5 to 62.5%. In conclusion, the increase in frequency of Treg cells might play a role in suppression of the immune response against HCC and for the design of immunotherapy the incorporation of the Treg cell depletion strategy will achieve potent anti-tumor immunity with therapeutic impact.

Expression of CIITA-related MHCII molecules in tumors linked to prognosis in hepatocellular carcinoma.

The prognosis of hepatocellular carcinoma (HCC) after surgery is poor due to its high recurrence rate. In order to unfold the mechanism of different recurrent-free survival (RFS) times following resection, expression profiling of tumor tissues from 32 HCC patients with different RFS time were used to identify differential expression of individual genes and signaling pathway components correlated with RFS time. Quantitative RT-PCR, Western blotting, and immunohistochemistry were used to validate the expression of selected genes. Up-regulation of several immune related genes and pathways, especially HLA II-related antigen presenting pathways, significantly correlated with longer RFS time. The expression of MHCII molecules were found to be mainly located in either CD68+ cells or CD45+ cells, and their expression significantly correlated with the expression of CIITA (HLA II genes transactivator) in the tumor. The results suggest that the high expression level of CIITA and MHCII molecules in hepatocellular carcinoma tissue is an effective prognostic marker for longer RFS time in HCC.

Specific CD8(+ )T cell responses to HLA-A2 restricted MAGE-A3 p271-279 peptide in hepatocellular carcinoma patients without vaccination.

The MAGE-A3 protein, one of the promising tumor antigens for immunotherapy, is highly expressed in human hepatocellular carcinoma (HCC). In this study, we estimated the specific CD8(+) T cell immune response to MAGE-A3 p271-279 peptide (M3(271)) in the peripheral blood of HCC patients without antigen vaccination in order to evaluate its immunotherapeutic potential in these patients. After expansion in vitro, the functional IFN-gamma producing M3(271) specific CD8(+) T cells were detected in 30.8% (8/26) of HLA-A2(+)MAGE-A3(+) HCC patients. The effector CD8(+ )T cells could release cytotoxic molecules of granzyme B and perforin after restimulation with natural HLA-A2(+)MAGE-A3(+) HCC cell lines in the samples tested. The functional supertype of HLA-A2 in the presentation of HLA-A*0201 restricted M3(271) peptide has been identified in the Chinese HCC patients of Han ethnicity, that widely expanded the applicability of this tumor peptide vaccine in Chinese HCC patients. Thus, the functionally detectable pre-existence of M3(271)-specific CD8(+) T cells in HCC patients makes M3(271) a potential target for immunotherapy in these patients. The responsive CD8(+ )T cells to both NY-ESO-1 and MAGE-A3 antigens provide a rationale for the application of a bivalent vaccine in HCC patients with tumors expressing both antigens.

[The frequency, phenotypes and functions of CD4+ CD25+ regulatory T cells in hepatocellular carcinoma patients].

OBJECTIVES: (1) To evaluate the prevalence, phenotypes and suppressive function of CD4+CD25+ regulatory T cells (Tregs) among the in peripheral blood mononuclear cells (PBMCs) and tumor-infiltration lymphocytes (TILs) from hepatocellular carcinoma (HCC) patients and patients with chronic hepatitis B. (2) To investigate the correlation between the frequency of CD4+CD25+ Tregs and clinical characteristics of HCC patients. METHODS: PBMCs and TILs in 18 HCC patients, 10 chronic hepatitis B (CHB) patients and 15 healthy donors were evaluated for the phenotypes of CD4+CD25+ Tregs and the proportion of CD4+CD25+ Tregs as a percentage of the total CD4+ cells, by flow cytometric analysis with three or four color staining. The relationship between the frequency of CD4+CD25+ Tregs and tumor TNM stages was analyzed. The CD4+CD25+ Tregs and CD4+CD25- T cells were isolated from PBMC of HCC patients and donors. The suppressive function of CD4+CD25+ Tregs was analyzed. RESULTS: The percentages of CD4+CD25+ Tregs of the HCC patients (6.38% +/- 6.30%) and CHB patients (4.29% +/- 1.82%) were significantly higher than those of the healthy donors (1.58% +/- 0.55%, P less than 0.01). Among the TILs, the percentage of CD4+CD25+ Tregs was higher (t = 4.39, P < 0.01). There were significant differences in the prevalence of CD4+CD25+ Tregs in early and advanced stage HCCs (stage II vs. III, P less than 0.05; stage II vs. IV P < 0.01). The proliferative capacity of CD4+CD25- T cells was inhibited by the presence of CD4+CD25+ T cells in a dose-dependent manner where the level of suppression was correlated to the ratio of the two-cell populations. CONCLUSION: These results suggest that the increase in frequency of CD4+CD25+ Tregs might play a role in the suppression of the immune response against HCC, which may contribute to the HCC cells that escaped from immunological surveillance.

The spontaneous CD8+ T-cell response to HLA-A2-restricted NY-ESO-1b peptide in hepatocellular carcinoma patients.

PURPOSE: Hepatocellular carcinoma (HCC) can express various cancer-testis antigens including NY-ESO-1, members of the SSX family, members of the MAGE family, SCP-1, and CTP11. Immunotherapy directed against these antigens is a potential alternative treatment for HCC. To date, it remains unclear whether HCC patients have spontaneous immune responses to these tumor antigens. The objectives of this study were to measure immune responses to NY-ESO-1, a promising cancer vaccine candidate, in HCC patients using the HLA-A2-restricted NY-ESO-1b peptide (p157-165) to measure cellular responses and whole protein to measure antibody responses. EXPERIMENTAL DESIGN: In HLA-A2(+) patients with NY-ESO-1(+) HCC, we analyzed T-cell antigen-dependent interferon (IFN)-gamma and/or Granzyme B release by enzyme-linked immunospot (ELISPOT) assay and IFN-gamma-producing intracellular cytokine flow cytometry (CytoSpot). As an assay independent of T-cell function, we performed tetramer staining. Antibodies to whole NY-ESO-1 were assayed by enzyme-linked immunosorbent assay. RESULTS: The frequency of specific CD8(+) T-cell responses to NY-ESO-1b in 28 NY-ESO-1 mRNA(+)HLA-A2(+) HCC patients was 35.7% (10 of 28). The average magnitude of effector CD8(+) T cells was 0.3% (89 +/- 59 per 2.5 x 10(4) CD8(+) cells) and 1.2% as measured by IFN-gamma release ELISPOT and CytoSpot assays, respectively. These in vitro induced NY-ESO-1b-specific CD8(+) T cells can also recognize HepG2 cells transfected with pcDNA3.1-NY-ESO-1 in both IFN-gamma and Granzyme B ELISPOT assays. Frequencies of NY-ESO-1b-specific T cells in several patients were confirmed by tetramer staining. Nonfunctional tetramer(+)CD8(+) T cells were also present. The CD8(+) T-cell response was apparently increased in patients with late-stage HCC. A discordance between antibody and CD8(+) T-cell responses in HCC patients was observed. CONCLUSIONS: The elevated frequency of specific CD8(+) T-cell responses to NY-ESO-1b in NY-ESO-1 mRNA(+)HLA-A2(+) HCC patients suggests that NY-ESO-1 is appropriate for use in the immunotherapy of HCC patients.

[The genetic polymorphism of melanoma-associated antigen 1 in Chinese normal donors and hepatoma patients].

OBJECTIVES: To investigate the expression of melanoma-associated antigen 1 (MAGE-1) in Chinese hepatocellular carcinoma (HCC) patients and to determine the existence and distribution of single nucleotide polymorphisms (SNP) of MAGE-1 gene. METHODS: Total RNA was extracted from cancer tissues and adjacent tissues from 19 HCC patients and the expression of MAGE-1 mRNA was examined by using RT-PCR. The PCR products were sequenced to analysis the gene variation. Genomic DNA was extracted from cancer tissues, adjacent tissues and peripheral blood cells of 19 HCC patients, as well as from peripheral blood cells of 23 healthy donors. The PCR product of MAGE-1 DNA was sequenced to determine the existence and distribution of SNPs of MAGE-1 gene. RESULTS: 9 of 19 (47.4%) tumor tissues and none of adjacent tissue from HCC patients expressed MAGE-1 mRNA. There were three kinds of gene variations of cDNA in 9 MAGE-1 mRNA positive patients. One type was named type I including 1 patient, which sequence is as same as that of the GenBank M77481. The other was named TGA type including 5 patients, which involved three nucleotide changes (C159T, A272G and G393A) and result in two amino acid changes (T32A and R72Q). Another one was named GTG type including 3 patients, which involved three nucleotide changes (A272G, C991T, A1125G) and result in only one amino acid changes (T32A). According to the analysis of genomic DNA, above three types were not specific mutations of tumor tissue, but were SNPs. These SNPs types were distributed in HCC patients and normal donors with the frequencies of 26.3% (5/19) and 60.9% (14/23) for type I, 57.9% (11/19) and 47.8% (11/23) for TGA type, and 21.1% (4/19) and 21.7% (5/23) for GTG type, respectively. The sequences of two new SNPs had been deposited in GenBank with the accession numbers of AF463515 and AY148486. In male population, the distributions of SNPs were not correlated to HCC suffering or MAGE-1 expression. Several new HLA-restricted epitopes were probably resulted from SNPs existing. The three-dimensional models of MAGE-1 proteins of type I and TGA type was established by using computer software. CONCLUSION: The expression rate of MAGE-1 gene in Chinese HCC patients is high. Three SNP types of MAGE-1 gene exist in Chinese population. The three-dimensional models of MAGE-1 proteins were obtained by computer processing. These results will be helpful to developing MAGE-1 peptide-vaccine for HCC immunotherapy.