Establishment of rat liver cancer cell lines with different metastatic potential.

The gloomy outcome of liver cancer is mainly due to the high rates of metastasis and recurrence, even after curative resection for early stage liver cancer. Our study was conducted to find the animal model suitable for the study of liver cancer metastasis. In our study, two liver cancer cells were obtained from N-nitrosodiethylamine (DEN) and N-nitrosomorpholine (NMOR) induced rats, and they were cultivated, screened and cloning cultivated. Bionomics of cells was analyzed. The results show that 2 cells had different metastatic potentiality. They were named Wrh-f2 and Wrh-s2, and they have the characteristics of Hepatocellular carcinoma cells. The bionomics of 2 cells showed: (1) The chromosome karyotype analysis showed that the mode of Wrh-f2 was 80-83 and Wrh-s2 was 55-57; (2) AFP positive cytoplasmic staining was observed in Wrh-f2 and Wrh-s2. Cytokeratin (CK) 7 and CK8 positive staining was present in Wrh-f2. CK8 positive staining was present in Wrh-s2; (3) The numbers of Wrh-f2 and Wrh-s2 that passed through the Transwells were 98 ± 12 and 55 ± 15;(4) Wrh-f2 had the significant higher colony formation (78%) than Wrh-s2(8%) (P < 0.01). (5) The animal models generated solid tumours when 2 cells were inoculated to nude mouse and rat. And Wrh-f2 developed stable pulmonary metastasis. The established cell lines with different metastatic potential showed obvious advantages over liver cancer in mimicking the biological properties of malignant liver cancer tumors. It provided a suitable model for the mechanism of liver cancer metastasis in vivo and in vitro.

The Effect of PCDH15 Gene Variations on the Risk of Noise-induced Hearing Loss in a Chinese Population.

Noise-induced hearing loss (NIHL) is a complex disease caused by interactions between environmental and genetic factors. This study investigated whether genetic variability in protocadherin related 15 (PCDH15) underlies an increased susceptibility to the development of NIHL in a Chinese population. The results showed that compared with the TT genotype of rs11004085, CT/CC genotypes were associated with an increased risk of NIHL [adjusted odds ratio (OR) = 2.64; 95% confidence interval (CI): 1.14-6.11, P = 0.024]. Additionally, significant interactions between the rs11004085 and rs978842 genetic variations and noise exposure were observed in the high-level exposure groups (P < 0.05). Furthermore, the risk haplotype TAGCC was observed when combined with higher levels of noise exposure (P < 0.05). Thus, our study confirms that genetic variations in PCDH15 modify the susceptibility to NIHL development in humans.

[Anti-tumor effect of cisplatin combined with DC vaccine on tumor-bearing mice].

OBJECTIVE: To explore the anti-tumor mechanism of the combination of cisplatin with DC vaccine in tumor-bearing mice. METHODS: B16 melanoma cells were treated with cisplatin at the final concentration of 20 µg/ml in vitro for 24 h. The expression of HMGB1, Hsp70 and TGF-ß were detected by Western blot. B16 tumor-bearing mouse models were generated. The therapeutic effect of the combination of cisplatin (100 µg/mouse i.p., for sequential 3 days) and intratumoral injection of DC cells (3×10(6)/mouse, twice with a 7-day interval) in the tumor-bearing mouse models was evaluated. Expression of MHC II, ICAM-1 and CD86 was analyzed by flow cytometry. The mice were sacrificed at 28 days after tumor cell inoculation. The tumors were removed and weighed, and tissue samples were taken for pathological examination. Tumor infiltrating lymphocytes (TIL) were isolated by discontinuous gradient centrifugation. The distribution of T-reg and CD8(+) T cells in the TIL was analyzed by flow cytometry, and the ratio of CD8(+) T/T-reg was determined. The activity of cytotoxic lymphocytes (CTL) was determined by microcytotoxicity assay. RESULTS: Cisplatin enhanced both the B16 cell apoptosis and HMGB1 expression. After loading with cisplatin-treated cell lysate, the expression of MHC II, ICAM-1 and CD86 on DC cells were (47.5 ± 8.8)%, (35.5 ± 8.3)% and (36.2 ± 9.2)%, respectively. At 28 days after tumor cell inoculation, the tumor weight of the control group was (2.1 ± 0.6) g, that of the cisplatin group was (0.3 ± 0.2) g and that of cisplatin + DC vaccine group was (0.5 ± 0.2) g, showing a significant inhibition of tumor growth (P < 0.01). Furthermore, the CD8(+) T/T-reg ratio and CTL activity in TIL were also significantly enhanced in the tumor-bearing mice treated with cisplatin + DC vaccine. When the effector-to-target ratio was 20:1, 10:1 and 5:1, the CTL activity in the cisplatin + DC vaccine treated mice was (25.0 ± 5.0)%, (22.0 ± 6.0)% and (14.0 ± 4.0)%, respectively, significantly higher than (8.2 ± 3.6)%, (6.7 ± 1.8)% and (3.6 ± 1.9)%, respectively, in the control group (all P < 0.01). CONCLUSION: Cisplatin promotes the anti-tumor effect of DC vaccine by down-regulating T-reg cells and enhancing the CTL activity in tumors.

Soy intake is associated with lower lung cancer risk: results from a meta-analysis of epidemiologic studies.

BACKGROUND: Although several in vitro and animal in vivo studies have suggested that soy or soy isoflavones may exert inhibitory effects on lung carcinogenesis, epidemiologic studies have reported inconclusive results on the association between soy intake and lung cancer. OBJECTIVE: The aim of this meta-analysis was to investigate whether an association exists between soy and lung cancer in epidemiologic studies. DESIGN: We searched PubMed, EMBASE, and the Cochrane Library from their inception to February 2011 for both case-control and cohort studies that assessed soy consumption and lung cancer risk. Study-specific risk estimates were combined by using fixed-effect or random-effect models. RESULTS: A total of 11 epidemiologic studies that consisted of 8 case-control and 3 prospective cohort studies were included. A significantly inverse association was shown between soy intake and lung cancer with an overall RR of 0.77 (95% CI: 0.65, 0.92). Findings were slightly different when analyses were restricted to 5 high-quality studies (RR: 0.70; 95% CI: 0.45, 0.99). In a subgroup meta-analysis, a statistically significant protective effect of soy consumption was observed in women (RR: 0.79; 95% CI: 0.67, 0.93), never smokers (RR: 0.62; 95% CI: 0.51, 0.76), and Asian populations (RR: 0.86; 95% CI: 0.74, 0.98). CONCLUSIONS: Our findings indicate that the consumption of soy food is associated with lower lung cancer risk. Because of different methods used to assess soy consumption across studies, more well-designed cohort studies or intervention studies that use unified measures of soy intake are needed to fully characterize such an association.

[Immunoadjuvant effect of Hsp70L1 in tumor vaccine].

AIM: To explore the immune enhancement of Hsp70L1 in the tumor cell vaccines. METHODS: TRP2(153-243) and Hsp70L1 genes were obtained by RT-PCR from B16 cells in murine melanoma and from spleens of C57BL/6 mice and then were inserted into pcDNA3.1/V5-His eukaryotic expression vectors respectively. The recombinants of pTRP2, pHSP70L1 or pTRP2-Hsp fusion gene were obtained and transfected into B16 cells respectively. TRP2(153-243), HSP70L1 or TRP2-Hsp fusion gene-expressing B16 cells were then induced to necrosis by freezing-thawing or to apoptosis by mitomycin C. C57BL/6 mice were immunized with the necrotic or apoptotic B16 cells twice, then the live B16 tumor cells were transplanted into the immunized mice and the tumor growth was observed in some tumor-bearing mice. IFN-gamma-producing cells in splenocytes were measured by flow cytometry and the CTL activity of spleno-lymphocyte was detected by LDH release assay. RESULTS: After the normal mice were immunized with the necrotic or apoptotic tumor vaccines modified with TRP2(153-243), Hsp70L1 or TRP2-Hsp fusion genes, CTL lysis activity and IFN-gamma production from the splenic lymphocytes were promoted in the groups of Hsp70L1 and TRP2-Hsp modified tumor vaccines (P<0.05 or P<0.01). Additionally, the tumor growth was inhibited obviously in the groups of mice immunized with necrotic tumor vaccines (P<0.05 or P<0.01). However, no marked inhibition of tumor growth was observed in the groups of mice immunized with apoptotic tumor vaccines (P>0.05). CONCLUSION: Hsp70L1 remarkably improves the immunogenicity of B16 tumor vaccines, especially that of necrotic tumor vaccines.

[Study on effects of anticancer and immunoregulation of Fuganchun 6 on hepatoma of mouse].

OBJECTIVE: To study the anticancerous effect of Fuganchun 6 (FGC-6) and its immunoregulatory effect on tumor-bearing mice. METHOD: The mice inoculated by H22 cells were divided into 5 groups: model group, 5-Fu group and FGC-6 in high dose, medium dose, and low dose groups. The normal mice were also observed. These mice were treated for 10 days. The weight of tumor mass and mouse were examined. The target-cell-killing activity of NK cells. The proliferation activity of lymphocyte and the production of IL-2 of murine splenocytes were detected respectively. The serum containing FGC-6 was prepared and its inhibition effect on H22 cells was examined by MTT assay and growth curve in vitro. RESULT: Growth of tumor was inhibited markedly by FGC-6 high dose. The inhibition of serum containing FGC-6 on the proliferation of H22 cells in vitro was observerd in a dose and time-dependent manner. The target-cell-killing activity of NK cells and the production of IL-2 of murine splenocytes of model group were lower than those of normal group (P < 0.05). When compared with model group, FGC-6 in high dose elevated the two indexes above-mentioned, and also enhanced the proliferation activity of lymphocyte markedly (P < 0.05). The production of IL-2 of murine splenocytes was also improved when treated by FGC-6 in medium dose (P < 0.05). CONCLUSION: FGC-6 can inhibite the growth of H22 cells markedly and also can strengthen the immunity of H22 transplanted mouse.

[Study on RAPD characteristics of five S180 clonal strains and on biological characteristics of passage cells from S180-S2D9].

OBJECTIVE: To study the random amplified polymorphic DNA (RAPD) characteristics of five S180, clonal cell strains with 23 primers and the biological characteristics of passage cells from S180-S2D9. METHODS: The DNA of 5 clone strains of S180 including S180-S2D9, S180-S2D7, S180-S1F11, S180-S1H10 and S180-S1B11, was amplified with RAPD-PCR using 23 single primers. The PCR products were resolved with electrophoresis on agarose gel. To analyze genomic DNA with RAPD, the cultured cells in vitro were treated with colchicine for 6 hours. Then, the chromosome numbers of 100 cells were examined under the microscope. The KM mice were injected intraperitoneally with 0.2 ml solution of S180-S2D9 cell, and the growth of ascitic fluid and the life span of the mice were observed. The cultured cells were fixed with 750 ml/L ethanol, and DNA analysis was made by Flow Cytometry. RESULTS: Three of the 23 single primers resulted in diversity between amplified products from different clonal strains. RAPD character of S180-S2D9 was analyzed by the 3 single primers; RAPD bands of the first generation, 25th generation, 50th generation and 75th generation showed no difference; ANOVA showed that the average numbers of chromosomes of four generations were of no significant difference (P>0.05). The ascites of the KM mice subjected to the intraperitoneal injection of first generation and 50th generation S180-S2D9 cells was bloody, and the survival days of mice were 13-23 d and 13-20 d respectively; ANOVA showed there was no significant difference between the first generation and 50th generation (P>0.05). DNA contents assayed by flow cytometry revealed that DNA corresponding content of the cells is individually 0.3890, 0.3542, 0.3575 and 0. 3984. These results imply that the S180-S2D9 passage cells have not been found to vary a lot. CONCLUSION: It is adaptable to give quality control to the clonal cell strains with RAPD.