Overexpression of PD-L1 causes germ cells to slough from mouse seminiferous tubules via the PD-L1/PD-L1 interaction.

Spermatogenesis is a cyclical process in which different generations of spermatids undergo a series of developmental steps at a fixed time and finally produce spermatids. Here, we report that overexpression of PD-L1 (B7 homolog1) in the testis causes sperm developmental disorders and infertility in male mice, with severe malformation and sloughing during spermatid development, characterized by disorganized and collapsed seminiferous epithelium structure. PD-L1 needs to be simultaneously expressed on Sertoli cells and spermatogonia to cause spermatogenesis failure. After that, we excluded the influence of factors such as the PD-L1 receptor and humoral regulation, confirming that PD-L1 has an intrinsic function to interact with PD-L1. Studies have shown that PD-L1 not only serves as a ligand but also plays a receptor-like role in signal transduction. PD-L1 interacts with PD-L1 to affect the adhesive function of germ cells, causing malformation and spermatid sloughing. Taken together, these results indicate that PD-L1 can interact with PD-L1 to cause germ cell detachment and male infertility.

PD-L1/PD-L1 signalling promotes colorectal cancer cell migration ability through RAS/MEK/ERK.

Programmed death ligand 1 (PD-L1) is widely known as an immune checkpoint, and immunotherapy through the inhibition of checkpoint molecules has become an important component in the successful treatment of tumours via programmed death 1 (PD-1)/PD-L1 signalling pathways. However, its biological functions and expression profile in colorectal cancer (CRC) are elusive. We previously found that PD-L1 can bind to PD-L1 and cause cell detachment. However, the detailed molecular mechanisms of how PD-L1 binds to PD-L1 and how it transmits signals to the cell remain unclear. In this study, we disclosed that PD-L1 expression was dramatically upregulated in CRC compared to normal tissues. Ectopic expression of PD-L1 inhibits cell adhesive capacity and promotes cell migration in CRC cell lines, while silencing PD-L1 had the opposite effects and suppressed invasion and proliferation. Mechanistically, PD-L1 was found to promote epithelial-mesenchymal transition (EMT) through the ERK signalling molecule pathway and interacted with the 1-86 aa fragment of KRAS to transduce signals. Collectively, our study demonstrated the role of PD-L1 after binding to PD-L1 in CRC, thereby providing a new theoretical basis for further improving immunotherapy with anti-PD-L1 antibodies.

Polymorphisms in the vitamin D receptor and risk of gout in Chinese Han male population.

Previous studies have showed that patients with gout showed lower serum 25(OH)D levels. As the specific receptor of vitamin D, VDR plays an important role in regulating immune system by combining with vitamin D. In this study, we investigated whether the functional VDR polymorphisms were associated with susceptibility to gout in Chinese Han male population. A total of 504 patients with gout and 523 gout-free controls were recruited from the Affiliated Hospital of the Medical College, Qingdao University. Genotyping of VDR rs11568820, rs2228570 and rs1544410 was performed by TaqMan allele discrimination assays. An association analysis was carried out using the χ(2) test. A genotype-phenotype analysis was also conducted. Our results showed that polymorphisms of rs11568820 and rs1544410 in VDR were associated with gout in Chinese Han male population. The A allele of both rs11568820 and rs1544410 was associated with the risk of gout [P = 0.012 OR 1.251, 95% CI (1.051-1.490); P = 0.006, OR 1.574, 95% CI (1.139-2.175)]. However, there was no statistic significance between rs2228570 and gout (P = 0.186). Our study suggested that the polymorphisms of VDR may be relevant host susceptibility factors for the development of gout in Chinese Han male population. However, further study should be done in a larger size sample and other ethic to test and verify our result.

Prognostic Value of CD9 in Solid Tumor: A Systematic Review and Meta-Analysis.

Numerous clinical studies investigated how low expression of CD9 predicts poor prognosis of solid tumor. However, the results were inconclusive. This present meta-analysis was therefore performed to determine the prognostic value of CD9 expression in solid tumors. In this meta-analysis, 25 studies involving 5,555 participants were included; the result showed strong significant associations between declined expression of CD9 and all endpoints: overall survival (OS) (hazard ratio (HR) = 1.88, 95% CI = 1.45-2.43, p < 0.000) and time to progression (TTP) (HR = 2.0, 95% CI = 1.38-2.88, p < 0.000). The subgroup analysis was also performed, which revealed that the associations between CD9 downregulated expression related to poor OS in lung cancer and head and neck cancer. Also, low expression of CD9 was significantly connected with poor TTP in patients with head and neck cancer. The adverse prognostic impact of decreased expression of CD9 was observed in patients of different ethnicities. In conclusion, these results showed that declined expression of CD9 was associated with poor survival in human solid tumors. CD9 may be a valuable prognostic predictive biomarker and a potential therapeutic target in human solid tumors.

[Analysis of differential gene expression in rat hepatic stellate cells activated by culture or hepatocellular carcinoma cell induction].

OBJECTIVE: Hepatic stellate cells (HSC) in hepatocellular carcinoma (HCC) transdifferentiate into extracellular matrix-producing myofibroblasts. Activated HSC can promote invasion and metastasis of HCC. To understand the differences of HSC in normal liver and HCC, we compared the gene expression patterns in HCC cell induction-activated and culture-activated rat HSC. METHODS: HSC were isolated by density centrifugation and exposed to conditioned medium from rat HCC cell line C5F. Expression of 22 012 genes in quiescent HSC, culture-activated HSC and HCC induction-activated HSC was analyzed by cDNA microarray and confirmed by real-time RT-PCR and Western blot. RESULTS: 1672 genes were differentially expressed in culture-activated HSC, including proinflammatory factors, cell adhesion molecules, cell surface receptors, signaling transduction molecules and immune factors. 711 genes were differentially expressed in HCC induction-activated HSC. Some of them were identical to those in culture-activated HSC. HCC Induction-activated HSC showed specific gene expression patterns, including Raf1, Rac2, Adam17, Wnt6, MMP-9 and TNF, suggesting that HCC cells can specifically induce HSC activation. CONCLUSION: The gene expression patterns in HCC induction-activated HSC are different from those in culture-activated HSC. HCC induction-activated HSC may play a major role in the invasion and metastasis of HCC. In vivo activation should be considered as the standard for the study of HSC biology. HCC induction-activated HSC should be considered as the standard for HSC biology studies.

[Analysis of the expression of Slit/Robo genes and the methylation status of their promoters in the hepatocellular carcinoma cell lines].

OBJECTIVE: To analyze the expression of genes in the Slit/Robo signaling pathway, and the methylation status of their promoters in hepatocellular carcinoma (HCC) cell lines. METHODS: Genomic DNA and total RNA were isolated from 9 HCC cell lines of different metastatic ability (Hep3B, HepG2, PLC/PRF/5, SMMC-7721, BEL-7402, MHCC97-H, MHCC97-L, LM3, LM6) and a control cell line L-02. The expression profiles of Slit1, Slit2, Slit3, Robo1, and Robo3 were analyzed by reverse transcription polymerase chain reaction (RT-PCR). The methylation status of the promoters was detected by methylation specific polymerase chain reaction (MSP). RESULTS: The promoters of Slit1, Slit2 and Slit3 genes were almost methylated in all the HCC cell lines. The Slit1 and Slit3 RNAs were not detected in most of the cell lines. Furthermore, the mRNA Slit2 was decreased gradually as the metastatic potential of the cell lines increased. As the candidate ligand of the Slit2 gene, Robo1 was frequently methylated in HCC cell lines whereas its mRNA was detected in all of these cells except SMMC-7721, BEL-7402 and L-02. Robo3 was unmethylated in HCC cell lines while its mRNA was not detected in these HCC cell lines. CONCLUSION: The hypermethylation status of Slit/Robo signaling pathway related genes is a universal event in the HCC. The hypermethylation status of Slit1, Slit2, Slit3 genes associated with the loss of expression or reduced expression. Those data suggest that Slit/Robo pathway may play a significant role in the progress or metastasis of HCC.

Oxidative decomposition of p-nitroaniline in water by solar photo-Fenton advanced oxidation process.

The degradation of p-nitroaniline (PNA) in water by solar photo-Fenton advanced oxidation process was investigated in this study. The effects of different reaction parameters including pH value of solutions, dosages of hydrogen peroxide and ferrous ion, initial PNA concentration and temperature on the degradation of PNA have been studied. The optimum conditions for the degradation of PNA in water were considered to be: the pH value at 3.0, 10 mmol L(-1) H(2)O(2), 0.05 mmol L(-1) Fe(2+), 0.072-0.217 mmol L(-1) PNA and temperature at 20 degrees C. Under the optimum conditions, the degradation efficiencies of PNA were more than 98% within 30 min reaction. The degradation characteristic of PNA showed that the conjugated pi systems of the aromatic ring in PNA molecules were effectively destructed. The experimental results indicated solar photo-Fenton process has more advantages compared with classical Fenton process, such as higher oxidation power, wider working pH range, lower ferrous ion usage, etc. Furthermore, the present study showed the potential use of solar photo-Fenton process for PNA containing wastewater treatment.

[Interferon-alpha upregulates thymidine phosphorylase expression via JAK-STAT transcriptional activation and mRNA stabilization in human hepatocellular carcinoma SMMC-7721 cells].

OBJECTIVE: To examine how the thymidine phosphorylase (TP) gene expression is upregulated by interferon-alpha (IFN-alpha) in human hepatocellular carcinoma SMMC-7721 cells. METHODS: TP mRNA levels were determined by RT-PCR. Whether the JAK-STAT cascade mediates IFN-alpha-induced TP mRNA expression was studied by pretreatment with Janus Kinase (JAK) inhibitor, AG-490. Effects of IFN-alpha on TP mRNA stability were detected with additional actinomycin D. RESULTS: The expression of TP mRNA was induced by IFN-alpha in a dose- and time-dependent manner in SMMC-7721 (human hepatocellular carcinoma) cells. TP mRNA levels rose at 8 h, reached the peak value at 12 h, and remained at a high level up to 72 h in SMMC-7721 cells treated with IFN-alpha 10000 U/ml. IFN-alpha at a dose of 5000 or 10000 U/ml up-regulated TP expression about 3 fold compared with that of non-treated cells (P < 0.05). Induction of TP mRNA expression by IFN-alpha was significantly inhibited in SMMC-7721 cells by pretreatment with AG-490, in comparison with that treated with IFN-alpha alone. Pretreatment of SMMC-7721 cells with IFN-alpha 10000 U/ml for 24 h caused a substantial stabilization of TP mRNA, with a half-live of 35.8 h, compared with 8.5 hr in the control SMMC-7721 cells. CONCLUSION: IFN-alpha at certain doses upregulates TP mRNA expression via both JAK-STAT transcriptional activation and post-transcriptional mRNA stabilization in human hepatocellular carcinoma SMMC-7721 cells.

[Screening for differential methylation status by CpG island microarray in the hepatocellular carcinoma cell lines].

OBJECTIVE: To profile the methylation alterations of CpG islands in hetpatocellular carcinoma cell lines. METHODS: A global analysis of DNA methylation using the Human CpG-island 12K Array (HCGI12K) from Canada University Health Network was performed on nine human hepatocellular carcinoma (HCC) cell lines (Hep3B, HepG2, PLC/RPF/5/RPF/5, SMMC-7721, BEL-7402, MHCC97-H, MHCC97-L, HCCLM3, HCCLM6) and a control cell line Chang's liver. Metastatic potential related alterations were also screened in MHCC97 series cell lines (MHCC97-H, MHCC97-L, HCCLM3, HCCLM6), using MHCC97-L, a cell line with low metastatic potential, as control. To screen the key genes which are hypermethylation or hypomethylation in the HCC cell lines compared with the normal liver cell line by normalization processing and cluster analysis of microarray data. Two randomly selected genes was analyzed by methylation specific PCR to verify the chip results. RESULTS: By a standard of methylation alteration ratio > or = 2 or < or = 0.5, fifty-eight CpG island cloning sites and sixty-six upstream or downstream tumor-related genes were identified. The genes were oncogenes, tumour suppressor genes and their ligand genes, apoptosis-related genes, cell proliferation and differentiation genes, cell cycle-related gene and cell signaling pathway key genes such as Wnt, ras, and FGF pathway-related genes. The methylation specific PCR results were consistent with those obtained by chips. CONCLUSION: The results of this study demonstrate that there are a series of CpG island methylation alterations in HCC cell lines. The expression of many oncogenes, tumor suppressor genes and other key genes may be up- or down-regulated, respectively, because of their CpG island hypomethylation or hypermethylation accordingly. It may provide a basis for screening HCC biological markers by CpG island methylation profilling.

More than chemotaxis: a new anti-tumor DC vaccine modified by rAAV2-SLC.

Secondary lymphoid tissue chemokine (SLC) is strongly expressed in secondary lymphoid organs. Its ability to facilitate chemotaxis of both dendritic cells (DC) and T cells makes it a promising candidate for cancer therapy. In this study, we modified a BMDC vaccine by incorporating the SLC mature peptide gene. The efficacy of this vaccine was evaluated using a mouse hepatocellular carcinoma (HCC) model, with rAAV2 as the gene delivery vector. The rAAV2 encoding SLC (rAAV2-SLC) transfected immature BMDCs at high efficiency and the anti-tumor effects of SLC gene modified BMDCs (rAAV2-SLC/BMDC) were evaluated. In addition, rAAV2-SLC/BMDC vaccine injected directly into tumors attracted more CD4(+) and CD8(+) T lymphocytes into tumors and showed stronger anti-tumor effects than footpad delivery. Moreover, we found that the phenotypic expression of MHC II, the secretion of IL-12 and IFN-gamma, and T cell stimulation were increased in vitro following treatment with rAAV2-SLC/BMDC vaccine and these responses were inhibited by PTX. In vivo, PTX also inhibited the anti-tumor effects of the vaccine. The results suggest that the expression of SLC by rAAV2-SLC/BMDC plays more than a chemotactic role in anti-tumor responses, thus these studies further demonstrate that SLC has potential to be valuable in cancer therapy.

[Effect of siRNA targeted against survivin on the malignant behaviors of human hepatoma cells].

OBJECTIVE: To study survivin expression in human hepatoma cells and the effects of survivin siRNA on the malignant phenotypes of human hepatocellular cell line HCCLM6. METHODS: Four hepatocellular carcinoma (HCC) cell lines were used. Semi-quantitative RT-PCR and Western blot were used to measure and compare their survivin expressions. The siRNA expression vector pshRNA-survivin targeting the mRNA of survivin and vector pGPU6/GFP/Neo-NC (as a control) were constructed, and then transfected into HCCLM6 cells. FQ-PCR was used to quantify the mRNA levels of survivin. The malignant phenotypes of transfected HCCLM6 cells, including invasive activities and adhesive capabilities, were analyzed. RESULTS: Survivin expression gradually increased with the increase of the invasion and metastasis behaviors of the four HCC cell lines (P<0.05). The expression of survivin was highest in cell line HCCLM6. Survivin mRNA level was decreased by 93.500%+/-3.117% after the pshRNA-survivin transfection. The cell adhesion rates significantly decreased in the cells transfected with pshRNA-survivin (cell adhesion rates were 11.403%+/-1.256% vs 32.545%+/-1.367%, t=20.732, P<0.01). The migrating number of HCCLM6 cells (13.5+/-0.9) transfected with pshRNA-survivin was also significantly decreased (t=14.5, P<0.01) as compared with the control group (32.6+/-1.4). CONCLUSION: The expression of survivin in HCC might have a close relationship to their invasion and metastasis properties. Sequence-specific shRNA can significantly reduce the survivin expression in the HCCLM6 cell line. Suppression of survivin expression in HCCLM6 cells transfected with pshRNA-survivin can reduce their invasive and adhesive capabilities.

[The biological function of peroxiredoxin II on Hep3B cells and its underlying mechanism].

OBJECTIVES: To study the biological function and its possible underlying mechanism of peroxiredoxin II (PrxII) in liver cancer cell line Hep3B. METHODS: Two pairs of double-stranded small interfering RNA (siRNA) targeted on PrxII gene were transfected into Hep3B cells using LipofectamineTM 2000. After confirming the inhibited effects of these siRNAs through Quant SYBR Green polymerase chain reaction and Western blot, the biological characters of Hep3B cell were analyzed by flow cytometry analysis, MTT and colony formation assays. Furthermore, dichlorodihydrofluorescein diacetate (DCFH-DA) and thiobarbituric acid (TBA) assays, for measuring the products of oxidative reaction, such as the reactive oxygen species (ROS) and malondialdehyde (MDA), were applied to explore whether the antioxidant mechanism was involved in the effects of PrxII functioning on Hep3B cell. RESULTS: The two pairs of siRNA significantly inhibited PrxII mRNA and protein expression. Compared to the mock and blank control groups, the two PrxII-silent groups showed decreased rates of cell growth and clone formation and increased rates of cell apoptosis. The numbers of the formed colonies were 42.0+/-2.8 and 40.5+/-0.7 respectively in the two PrxII-silent groups, while they were 121.5+/-2.1 and 130.0+/-1.4 in the mock and blank control groups (P less than 0.05). The levels of endogenous ROS and MDA were significantly higher in the two PrxII-silent groups than those in the mock and blank control groups (P less than 0.05). CONCLUSION: PrxII might play an important role in the hepatocarcinogenesis, possibly through an antioxidant function which may provide a favorable microenvironment for cancer cell survival and progression.

[Functional localization of metastasis suppressor genes for HCC on human chromosome 8].

OBJECTIVE: We previously showed that introduction of a normal, neomycin-tagged human chromosome 8 reduced the metastatic capacity of C5F rat liver cancer cell line, which had high metastatic potential without affecting tumorigenicity, suggesting the presence of one or more metastasis suppressor genes encoded on human chromosome 8. We proceeded to define further the region harboring the metastasis suppressor gene(s) and to determine the random loss of human chromosome 8 by PCR amplification of sequence tag site (STS) markers. METHODS: The national Center for Biotechnology Information (NCBI) databases were used as references of the relative genetic distances of the STS markers. C5F genomic DNA and A9/neo8 genomic DNA were used as negative and positive controls for chromosome 8 amplification, respectively. Genomic DNA was isolated and quantified from cultured hybrid clones (A9/C5F-1 and A9/C5F-2 microcell hybrid clones served as metastasis-unsuppressed groups; A9/C5F-4, A9/C5F-8 and A9/C5F-10 microcell hybrid clones served as metastasis suppressed groups). STS-PCR products were separated by electrophoresis through 2% agarose gel. RESULTS: Metastasis-suppressed microcell hybrid clones (A9/C5F-4, A9/C5F-8 and A9/C5F-10) conserved STS markers between D8S542 --> D8S1973 (8p21.1-23.1). In contrast, metastasis-unsuppressed clones (A9/C5F-1 and A9/C5F-2) lacked several markers in this region. In attempts to refine the region retained in the microcell suppressed clones, more densely spaced STS markers in the human chromosome 8p21.1-23.1 were used. We found that the metastasis-suppressed clones retained 18cM region between D8S542 and D8S1973 (8P21.1-23.1), where as the metastasis-unsuppressed clones lacked the region. CONCLUSION: Our results suggest that a metastasis suppressor gene is located within the interval between D8S542 and D8S1973 on human chromosome 8p21.1-23.1.

Inhibition of growth and metastasis of human hepatocellular carcinoma by antisense oligonucleotide targeting signal transducer and activator of transcription 3.

PURPOSE: Hepatocellular carcinoma (HCC) is an aggressive malignancy and is a devastating clinical complication of chronic liver disease. Therapeutic options are limited mainly because the genetic and biochemical understanding of this disease remains fragmented. We intended to study the role of signal transducer and activator of transcription 3 (STAT3) aberrant signaling in HCC malignancy, and the therapeutic potential of inhibition of STAT3 expression for HCC. EXPERIMENTAL DESIGN: A 2'-O-methoxyethylribose-modified phosphorothioate antisense oligonucleotide (ASO) was used to knock down STAT3 expression in different human HCC cell lines, including the highly metastatic HCCLM3 derived from orthotopic implantation and subsequent lung metastasis in athymic mice. The effects of STAT3 ASO treatment on HCC cells, metastasis, and animal survival following HCCLM3 orthotopic implantation were evaluated. RESULTS: Specific suppression of phosphorylated STAT3 reduced its DNA-binding activity, inhibited the expression of vascular endothelial growth factor, survivin, matrix metalloproteinases 2 and 9, reduced cell proliferation and migratory potential, induced apoptosis in vitro, and inhibited intradermal angiogenesis and s.c. tumorigenesis upon injection in mice. In mice bearing orthotopically implanted HCCLM3, STAT3 inhibition following therapeutic treatment with STAT3 ASO reduced circulating vascular endothelial growth factor and basic fibroblast growth factor, decreased intratumor CD34-positive microvessel density, intrahepatic and intraperitoneal transmission, and lung metastasis. HCC tumor volume and weight were reduced and the survival time of mice bearing orthotopically xenografted HCC was approximately doubled in STAT3 ASO-treated mice (P < 0.05). CONCLUSIONS: Constitutively activated STAT3 is essential for the growth, survival, and metastasis of HCC, suggesting that STAT3-targeted therapy may have utility for HCC.

Degradation of azo dye Acid black 1 using low concentration iron of Fenton process facilitated by ultrasonic irradiation.

A combination of ultrasonic and low concentration iron (<3 mgL(-1)) of Fenton process (US/Fenton) has been used to treat wastewater containing Acid black 1 (AB1). The results show that the oxidation power of low concentration iron of Fenton could be significantly enhanced by ultrasonic irradiation. The degradation of AB1 in aqueous solution by US/Fenton can receive better results compared with either Fenton oxidation or ultrasonic alone. Many operational parameters, such as ultrasonic power density, the pH value, the Fe(2+) dosage, the H(2)O(2) dosage, AB1 concentration and the temperature, affecting the degradation efficiency were investigated. Also, the effects of various inorganic anions (such as Cl(-), NO(3)(-), CO(3)(2-), etc.) on the oxidation efficiency of US/Fenton were studied. Under the given test conditions, 98.83% degradation efficiency was achieved after 30 min reaction by US/Fenton. The effect of various inorganic anions was in the following decreasing order: SO(3)(2-)>CH(3)COO(-)>Cl(-)>CO(3)(2-)>HCO(3)(-)>SO(4)(2-)>NO(3)(-). The results show that the US/Fenton can be an effective technology for the treatment of organic dyes in wastewater.

A kinetic study on the degradation of p-nitroaniline by Fenton oxidation process.

A detailed kinetic model was developed for the degradation of p-nitroaniline (PNA) by Fenton oxidation. Batch experiments were carried out to investigate the role of pH, hydrogen peroxide and Fe(2+) levels, PNA concentration and the temperature. The kinetic rate constants, k(ap), for PNA degradation at different reaction conditions were determined. The test results show that the decomposition of PNA proceeded rapidly only at pH value of 3.0. Increasing the dosage of H(2)O(2) and Fe(2+) enhanced the k(ap) of PNA degradation. However, higher levels of H(2)O(2) also inhibited the reaction kinetics. The k(ap) of PNA degradation decreased with the increase of initial PNA concentration, but increased with the increase of temperature. Based on the rate constants obtained at different temperatures, the empirical Arrhenius expression of PNA degradation was derived. The derived activation energy for PNA degradation by Fenton oxidation is 53.96 kJ mol(-1).

[Interferon alpha enhances the sensitivity of SMMC-7721 hepatocellular carcinoma cells to 5'-deoxy-5-fluorouridine related to up-regulation of thymidine phosphorylase].

OBJECTIVE: To observe changes of sensitivity to 5'-deoxy-5-fluorouridine (5'-dFUrd), and 5-fluorouracil (5-FU) in SMMC-7721 hepatocellular carcinoma cells by interferon alpha (IFN-alpha), and its relationship with the expression of thymidine phosphorylase (TP). METHODS: TP mRNA expression was determined by RT-PCR. Cytotoxicity of 5'-dFUrd, and 5-FU against SMMC-7721 cells was evaluated by MTT assay. RESULTS: Expression levels of TP mRNA was elevated in SMMC-7721 cells after cultured with IFN-alpha, which was a concentration- and time-dependent increase. After SMMC-7721 cells was treated in the concentration of 5000 U/ml, and 10 000 U/ml IFN-alpha, the level of TP mRNA was significantly higher than that in untreated control (P < 0.05). When SMMC-7721 cells was cultured with the concentration 10 000 U/ml IFN-alpha, the level of TP mRNA rose at 8hr, reached the peak value at 12hr, and remained high level up to 72hr. IFN-alpha enhanced the sensitivity of SMMC-7721 cells to 5'-dFUrd with dose-dependent increase. IFN-alpha (10 000 U/ml) reduced IC(50) of 5'-dFUrd from (102.1 +/- 18.4) micromol/L to (34.2 +/- 4.1) micromol/L (P < 0.05). There was no obvious relation between use of IFN-alpha and 5-FU sensitivity. IC(50) of 5-FU was (5.8 +/- 2.0) micromol/L and (6.3 +/- 1.4) micromol/L in with IFN-alpha (10 000 U/ml) and control group, respectively. Under the use of interferon, sensitivity to 5'-dFUrd increased positively related to up-regulation of TP mRNA expression. CONCLUSION: IFN-alpha enhanced cytotoxicity of 5'-dFUrd against SMMC-7721 cells positively related to its induction of TP mRNA.

[Osteopontin promotes the malignant phenotypes of human hepatocellular carcinoma cell line SMMC-7721].

OBJECTIVE: To study the effects of osteopontin (OPN) on the phenotypes of human hepatocellular carcinoma cell line SMMC-7721. METHODS: Human hepatocellular carcinoma SMMC-7721 cells were transfected with plasmid pcDNA 3.1(-)/OPN and cells transfected with a mock plasmid served as controls. OPN expression was verified by RT-PCR and Western blot, and concentrations of OPN, MMP-2, MMP-9 and uPA were measured by ELISA. A series of functional assays in vitro were used to monitor the changes of SMMC-7721 malignant phenotypes. RESULTS: OPN expression of SMMC-7721 cells was elevated after transfection. Concentrations of OPN, MMP-2 and uPA in the medium of SMMC-7721 cells after transfection were higher than those of the controls [(3.02+/-0.12) ng/ml vs (1.43+/-0.07) ng/ml, (43.04+/-3.06) ng/ml vs (22.15+/-4.34) ng/ml, and (4.78+/-0.70) ng/ml vs (1.61+/-0.34) ng/ml respectively, P less than 0.01], but MMP-9 concentration did not increase [(7.82+/-2.25) ng/ml vs (7.70+/-1.92) ng/ml]. Functional assays in vitro indicated that SMMC-7721 cells after transfection showed higher adhesive, migrant and invasive capabilities than those of the controls (cell adhesion rates were 75.33%+/-10.59% vs 57.34%+/-2.52%; number of outer surface cells in migrant assay was 14.33+/-2.51 vs 6.34+/-1.53; cell number in the invasive assay was 8.23+/-1.53 vs 4.12+/-1.29 respectively, P less than 0.05). CONCLUSION: OPN might enhance the expression of MMP-2 and uPA to promote malignant phenotypes of SMMC-7721 cells.

[A preliminary study of the killing function in vitro by T lymphocytes activated by dendritic cells loaded with exosomes secreted by hepatic cancer cell lines with high or low metastatic potentials].

OBJECTIVE: To study the tumor cell killing function of T lymphocytes stimulated by dendritic cells (DC) and to analyze the differences of protein contents of exosomes in each type of cell. METHODS: The exosomes of hepatic cell lines with high (P group) or low (F group) metastatic potentials were isolated by a process of four-step centrifugation and the collected exosomes were observed under an electron microscope (EM). The tumor cell killing experiment was performed by adding T lymphocytes activated by DC loaded with exosomes from corresponding P and F group cells and was studied using 3H-TdR experiments. The proteomic analysis was performed by surface-enhanced laser desorption/ ionization time of flight mass spectrometry (SELDI-TOF-MS ) on the exosomes of P and F group cells. RESULTS: The density distribution and content of exosomes in the P group were not equal to those in the F group observed by EM. The CD80, CD86, MHC-I and MHC-II in the P group were 64.27+5.00, 44.89+10.11, 84.35+19.89 and 59.03+19.37, and those in the F group were 71.53+4.85, 50.01+9.50, 80.68+29.87 and 58.86+21.11, respectively (P>0.05, compared with the control group). The counts per minute value in the P group was 528.40+179.06 and 78.80+24.44 in the F group after being loaded with exosomes (P<0.01, compared with the control group). There were significant differences between the proteins in the exosomes of hepatic cancer cell lines with high or low metastatic potentials. CONCLUSION: Exosomes have potential values of application in immunotherapy and in biotherapy for recurrences and metastases of hepatic carcinomas.

Serum CYFRA 21-1 level reflects hepatocellular carcinoma metastasis: study in nude mice model and clinical patients.

Our previous proteomics study on human hepatocellular carcinoma (HCC) cell strains revealed that cytokeratin 19 (CK19) was expressed in cells with high metastasis potential; we further studied serum CK19 fragment CYFRA 21-1 level in HCC patients and nude mice model of HCC metastasis. HCC cell line HCCLM3 was injected subcutaneously into 30 nude mice which were then randomized into 6 groups of 5 mice each. The murine serum CYFRA 21-1 and pulmonary metastases were determined 2, 3, 4, 5, 6, and 7 weeks after injection. Serum CYFRA 21-1 levels of 101 normal controls and 108 HCC patients were also determined. In nude mice model, CYFRA 21-1 level increased significantly when pulmonary metastases occurred. Among 108 HCC patients, 24 (22.2%) had increased serum CYFRA 21-1 level. The presence of portal vein tumor emboli was significantly higher in CYFRA 21-1 increased cases (33.3%, 6/24) than in CYFRA 21-1 normal cases (6.0%, 5/84) (x2=7.403, P < 0.01). In addition, the percentage of TNM stage III/IV tumor was significantly higher in CYFRA 21-1 increased patients (54.2%, 13/24) than in CYFRA 21-1 normal cases (21.4%, 18/84) (x2=9.776, P < 0.005). These results suggest that CK19 may play an important role in HCC metastasis.