Normal Human Liver Cell Line Research Articles

Radiosensitivity of hepatoma cell lines and human normal liver cell lines exposed in vitro to carbon ions and argon ions at the HIRFL

Human hepatoma (SMMC-7721) and normal liver (L02) cells were irradiated with γ-rays, 12C 6+ and 36Ar 18+ ion beams at the Heavy Ion Research Facility in Lanzhou (HIRFL). By using the Calyculin-A induced premature chromosome condensation technique, chromatid-type breaks and isochromatid-type breaks were scored separately. Tumor cells irradiated with heavy ions produced a majority of isochromatid break, while chromatid breaks were dominant when cells were exposed to γ-rays. The relative biological effectiveness (RBE) for irradiation-induced chromatid breaks were 3.6 for L02 and 3.5 for SMMC-7721 cell lines at the LET peak of 96 keVμm −1 12C 6+ ions, and 2.9 for both of the two cell lines of 512 keVμm −1 36Ar 18+ ions. It suggested that the RBE of isochromatid-type breaks was pretty high when high-LET radiations were induced. Thus we concluded that the high production of isochromatid-type breaks, induced by the densely ionizing track structure, could be regarded as a signature of high-LET radiation exposure.

Cytotoxic Activity and DNA-Binding Investigations of Two Benzoxanthone Derivatives

In this study, the interactions of two benzoxanthones 1,3-dihydroxy-12H-benzo[b]xanthen-12-one (1) and 9,11-dihydroxy-12H-benzo[a]xanthen-12-one (2) with calf thymus DNA (ct DNA) have been investigated by absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Experimental results suggested an intercalative mode with DNA for the two compounds; Furthermore, the binding affinity with DNA of 1 bearing linearly fused aromatic rings was higher than that of 2 bearing angularly fused aromatic rings according to the calculated binding constant values. In addition, three cell lines, the human cervical cancer cell line (HeLa), human hepatocellular liver carcinoma cell line (HepG2) and human normal liver cell line (L02) were used to evaluate the cytotoxic activities of the two benzoxanthones in vitro. As the results, they showed significant cytotoxic activity against the tumor cell lines HeLa and HepG2, but weak cytotoxic activity against normal liver cell line L02.

Comparative plasma membrane-associated proteomics of immortalized human hepatocytes

This work was initiated with the purpose of purifying and identifying differentially expressed plasma membrane-associated proteins between human liver cancer cell line HepG2 and normal liver cell line L02. The combined strategy of sucrose density gradient centrifugation and subsequent phase partition was applied to obtain high-purity proteins of plasma membrane. Two-dimensional gel electrophoresis revealed the differential protein profile between the two cell lines. A total of 13 plasma membrane-associated proteins containing 10 up-regulated proteins and three down-regulated proteins in HepG2 cells were successfully identified by MALDI-Q-TOF mass spectrometry; they participate in multiple biological functions such as adhesion, proliferation, apoptosis, and signal transduction. The identified proteins could provide helpful reference in clinical investigations on potential candidates for diagnosis and therapy of liver cancer.

Experimental Therapy of Hepatoma with Artemisinin and Its Derivatives: In vitro and In vivo Activity, Chemosensitization, and Mechanisms of Action

ART and its derivatives, clinically used antimalarial agents, have recently shown antitumor activities. However, the mechanisms underlying these activities remain unclear. This study was designed to determine their antitumor efficacy and underlying mechanisms of action in human hepatoma cells. The in vitro cytotoxicities of ART, DHA, artemether, and artesunate were compared in human hepatoma cells, HepG2 (p53 wild-type), Huh-7 and BEL-7404 (p53 mutant), and Hep3B (p53 null), and a normal human liver cell line, 7702. Based on their activity and specificity, ART and DHA were further investigated for their in vitro and in vivo antitumor effects and their effects on the protein expression of genes associated with cell proliferation and apoptosis. ART and DHA exerted the greatest cytotoxicity to hepatoma cells but significantly lower cytotoxicity to normal liver cells. The compounds inhibited cell proliferation, induced G(1)-phase arrest, decreased the levels of cyclin D1, cyclin E, cyclin-dependent kinase 2, cyclin-dependent kinase 4, and E2F1, and increased the levels of Cip1/p21 and Kip1/p27. They induced apoptosis, activated caspase-3, increased the Bax/Bcl-2 ratio and poly(ADP-ribose) polymerase, and down-regulated MDM2. In mice bearing HepG2 and Hep3B xenograft tumors, ART and DHA inhibited tumor growth and modulated tumor gene expression consistent with in vitro observations. DHA increased the efficacy of the chemotherapeutic agent gemcitabine. ART and DHA have significant anticancer effects against human hepatoma cells, regardless of p53 status, with minimal effects on normal cells, indicating that they are promising therapeutics for human hepatoma used alone or in combination with other therapies.

Cellular Retinaldehyde-Binding Protein-Like (CRALBPL), a Novel Human Sec14p-Like Gene That Is Upregulated in Human Hepatocellular Carcinomas, May Be Used as a Marker for Human Hepatocellular Carcinomas

Sec14p-like lipid-binding domain (SEC14 domain) is an evolutionarily conserved protein domain often found in secretory proteins, such as Saccharomyces cerevisiae phosphatidylinositol transfer protein Sec14p, and in lipid-regulated proteins, such as GTPase-activating proteins, guanine nucleotide exchange factors, and neurofibromin. We have cloned a novel human gene, cellular retinaldehyde-binding protein-like (CRALBPL), containing SEC14 domain from the cDNA library of human fetal brain. The RT-PCR expression pattern of 16 adult human tissues indicated that CRALBPL was only expressed in brain, while it was expressed in all of seven human carcinoma cell lines we used, especially in human gastric adenocarcinoma cell line, human rhabdomyoma cell line, human hepatocellular carcinoma (HCC) cell line, and human prostatic carcinoma cell line. Further, we found that CRALBPL has a remarkably more abundant RT-PCR expression pattern in human HCC cell lines than in normal human liver cell line, and the same result was gained when RT-PCR expression patterns between human HCC specimens and normal human liver specimens were compared. We also found that CRALBPL is located mainly in cytoplasm in human liver cell line L-02, which is consistent with the common function of Sec14p-like domain family. Our results show that CRALBPL may be used as a marker for human HCCs.

New Sesquiterpene Formamides from the Marine Sponge Axinyssa sp.

AbstractChemical investigation of an extract of the marine sponge Axinyssa sp., collected from the South China Sea, led to the isolation and identification of two new sesquiterpene formamides, (4R*,5R*,10R*)‐4‐formamidoeudesm‐7‐ene (1) and (4R*,5R*,7S*,10R*)‐4‐formamidoeudesman‐11‐ol (2), together with the known 4α‐formamidogorgon‐11‐ene (3). Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR spectroscopy, high‐resolution ESI‐TOF mass spectrometry, as well as X‐ray single‐crystal diffraction experiments. Possible biosynthetic pathways for 1–3 were also proposed. The human nasopharyngeal cancer cell line CNE‐2, human cervical cancer cell line HeLa, and human normal liver cell line L02 were used to examine the cytotoxic activities of 1–3 in vitro. As the results, 1 showed significant cytotoxic activity against CNE‐2, HeLa, and L02 cell lines with the IC50 values of 13.8, 7.5, and 38.0 μg/ml, resp.

Adenovirus-delivered CIAPIN1 small interfering RNA inhibits HCC growth in vitro and in vivo

Hepatocellular carcinoma (HCC) is an aggressive cancer with a poor prognosis. The specific cellular gene alterations responsible for hepatocarcinogenesis are not well known. Cytokine-induced antiapoptotic molecule (CIAPIN1), a recently reported antiapoptotic molecule which plays an essential role in mouse definitive hematopoiesis, is considered a downstream effecter of the receptor tyrosine kinase–Ras signaling pathway. However, the exact function of this gene in tumors is not clear. In this study, we reported that CIAPIN1 is highly expressed in HCC as compared with non-tumor hepatic tissue (P < 0.05). We employed adenovirus-mediated RNA interference technique to knock down CIAPIN1 expression in HCC cells and observed its effects on HCC cell growth in vitro and in vivo. Among the four HCC and one normal human liver cell lines we analyzed, CIAPIN1 was highly expressed in HCC cells. Knock down of CIAPIN1 could inhibit HCC cell proliferation by inhibiting the cell cycle S-phase entry. Soft agar colony formation assay indicated that the colony-forming ability of SMMC-7721 cells decreased by ∼70% after adenovirus AdH1-small interfering RNA (siRNA)/CIAPIN1 infection. In vivo experiments showed that adenovirus AdH1-siRNA/CIAPIN1 inhibited the tumorigenicity of SMMC-7721 cells and significantly suppressed tumor growth when injected directly into tumors. These results suggest that knock down of CIAPIN1 by adenovirus-delivered siRNA may be a potential therapeutic strategy for treatment of HCC in which CIAPIN1 is overexpressed.

2-Methoxyestradiol inhibits hepatocellular carcinoma cell growth by inhibiting Cdc25 and inducing cell cycle arrest and apoptosis

2-Methoxyestradiol (2-ME) is a physiological metabolite of estrogen, which can inhibit growth of many types of tumor cells, including hepatocellular carcinoma, both in vitro and in vivo. The exact mechanisms of its action are still unclear. We have studied the mechanisms of growth inhibition of several of human and rat hepatoma and normal liver cells by 2-ME. Human (Hep3B, HepG2, PLC/PRF5) and rat (McA-RH7777, JM-1) hepatoma and normal rat (CRL-1439) and human (CRL-11233) liver cell lines were cultured in vitro, in presence of 2-ME, and its IC50s were determined. Cell cycle arrest, Cdc25 phosphatase inhibition and apoptosis induction were studied. Finally, the effect of 2-ME on the growth of JM-1 rat hepatoma cells in rat liver was determined in vivo. The IC50 range for growth inhibition of hepatoma cells was found to be between 0.5 and 3 microM. In contrast, normal rat hepatocytes and liver cell lines were resistant to 2-ME up to 20 microM. JM-1 cells were arrested in the G2/M phase of the cell cycle. Cdc25A and Cdc25B, cell cycle controlling phosphatases, activities were inhibited in vitro and 2-ME was found to likely bind to their catalytic site cysteines. As a consequence, their cellular substrates Cdk1 and Cdk2 were tyrosine phosphorylated. Caspase-3 was cleaved suggesting apoptotic cell death. Moreover, growth of JM-1 tumors, which were transplanted into rat liver, was also inhibited by treatment with 2-ME in vivo. 2-Methoxyestradiol is a selective, potent and relatively non-toxic hepatoma growth inhibitor both in vitro and in vivo. Cell cycle arrest of hepatoma cells was likely mediated by binding and inactivation of the Cdc25 phosphatases and induction of apoptosis.

Replication-incompetent adenovirus vector-mediated MDA-7/IL-24 selectively induces growth suppression and apoptosis of hepatoma cell Line SMMC-7721

In order to investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and normal liver cell line L02, the recombinant replication-incompetent Ad.mda-7 virus vector was constructed and infected into the HCC cell line SMMC-7721 and normal liver cell line L02. RT-PCR was performed to examine the expression of MDA-7 mRNA. The concentrations of MDA-7/IL-4 in culture supernatants were determined by using ELISA. MTT and Hoechst staining assay were applied to observe the inhibitory and killing effects of MDA-7 on the HCC cells. By using flow cytometry, the apoptosis, cell cycle and proliferation of SMMC-7721 and L02 cells were measured. The results showed recombinant replication-incompetent virus expressing MDA-7/IL-24 was constructed successfully, and RT-PCR revealed that it could mediate the high expression of the exogenous gene MDA-7/IL-24 in SMMC-7721 and L02 cells. The expression of MDA-7/IL-24 proteins in the culture supernatant was detectable by ELISA. Ad.mda-7 infection induced apoptosis and growth suppression in SMMC-7721 cells and an increased percentage of HCC cells in the G2/M phase of the cell cycle, but not in L02 cells. It was concluded that mda-7/IL-24 gene, mediated with replication-incompetent adenovirus vector, could selectively induce growth suppression and apoptosis in HCC cell line SMMC-7721 but without any toxic side-effect on normal liver line L02.

Enhanced sensitivity of hepatocellular carcinoma cells to chemotherapy with a Smac-armed oncolytic adenovirus

The aim of the present study was to further improve the therapeutic effects for human hepatocellular carcinoma (HCC) and reduce the damage in normal cells using a novel chemo-gene-virotherapeutic strategy. An oncolytic adenoviral vector (ZD55) similar to the typical oncolytic adenovirus ONYX-015, with a deletion of E1B-55K gene, was employed to express the second mitochondria-derived activator of caspases (Smac) protein by constructing a recombinant virus ZD55-Smac. The enhanced cytotoxicity of the combined treatment of ZD55-Smac with cisplatin or 5-fluorouracil (5-FU) was evaluated in several HCC cell lines. Moreover, the negative effects on normal cells have been tested in human normal liver cell lines L-02 and QSG-7701 cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and apoptotic cell staining. According to our observation, ZD55-Smac is superior to ONYX-015 in sensitizing chemotherapy, ZD55-Smac used in conjunction with chemotherapy was found to exhibit obviously enhanced cytotoxicity in HCC cells, yet significantly abolished the negative toxicity in normal cells by utilizing the tumor selective replication vector and reducing the dosage. This chemo-gene-virotherapeutic (cisplatin or 5-FU+ZD55-Smac) strategy is superior to the conventional chemo-gene or chemo-viro approach.

English

&nbsp; The CVP (Coriolus versicolor&nbsp;polysaccharide) is well known as anti-tumor drug in clinical applications. Although recent studies have demonstrated that CVP can inhibit the proliferation of cancer cells&nbsp;in vitro&nbsp;and&nbsp;in vivo, the different purity level of CVP has a different affect on various cancer cells. In this study, the crude CVP was extracted fromC. versicolor&nbsp;dry fruit bodies by hot-water extraction and ethanol precipitation.&nbsp;The content of CVP was 7.74% in the fruit bodies, while 54.69% in the crude extracts by phenol-vitriolic colorimetry.&nbsp;After that, the&nbsp;in vitro&nbsp;cytotoxic activities of the CVP were examined on the four human liver cancer (7703, HepG2, 7721, PLC) and four human breast cancer (Bcap37, ZR75-30, MCF-7, T-47D) cell lines using a MTT cytotoxicity assay. The results showed&nbsp;that the CVP inhibited the proliferation of 7703, Bcap37, T-47D in low concentration; the IC50&nbsp;values on&nbsp;7703, Bcap37 and T-47D were 18.37, 14.42 and 9.29 mg/l, respectively. The CVP also inhibited the proliferation of MCF-7 and ZR75-30, but at high concentration, the IC50&nbsp;values on MCF-7 and ZR75-30 were 39.26 and 34.59 mg/l, respectively. The CVP does not inhibit the proliferation of HepG2, 7721, PLC and&nbsp;human normal liver cell line (WRL). The CVP was found to selectively inhibit the proliferation of human liver cancer and human breast cancer. &nbsp; Key words:&nbsp;Coriolus versicolor, fruit body, polysaccharide, anti-tumor. &nbsp;

Differential proteomics in malignant and normal liver cell lines

ObjectiveTo detect differential protein expression in malignant and normal liver cell lines in vitro using the SELDI ProteinChip platform, for investigating the pathogenesis of liver cancer.MethodsTwo cell lines, human normal liver cell line L02 and hepatoma cell line SMMC-7721 were cultured routinely, harvested in good condition and lysed. After quantification, the supernatant of the lysate was tested by IMAC3 (Immobilized Mental Affinity Capture) and WCX2 (Weak Cation Exchange) chips on the SELDI-TOF-MS ProteinChip reader.ResultsProtein expression differed between the malignant and normal liver cell lines. A total of 20 differentially expressed proteins were found, among which, 7 were captured by the IMAC3 chip and 14 by the WCX2 chip. Peaks at 5,419, 7,979 and 11,265 Da were higher and at 8,103, 8,492, 10,160 and 11,304 Da lower in SMMC-7721 cells by the IMAC3 chip; peaks at 7,517, 7,945 and 7,979 Da were higher and at 5,061, 5,551, 5,818, 7,439, 9,401,10,100, 10,312, 11,621, 11,662, 11,830 and 12,772 Da lower in SMMC-7721 cells by the WCX2 chip. Interestingly, both chips captured the 7,979 Da peak. In addition, the 11,081 Da peak corresponded precisely with the molecular mass of the calcium binding protein S100A10, which may participate in the formation of liver cancer in association with p36.ConclusionDetecting differential protein expression in malignant and normal liver cell lines using the SELDI ProteinChip platform was simple, sensitive and repeatable. The results we obtained can serve as a basis for investigating the pathogenesis of liver cancer and aid the discovery of new therapeutic targets.

Induction of apoptosis in SGC-7901 cells by polysaccharide-peptide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

The biological function of GFPPS1b, a novel polysaccharide-peptide isolated from cultured mycelia of Grifola frondosa GF9801, was well investigated. GFPS1b has anti-tumor activity and can significantly inhibit the proliferation of SGC-7901 cells, whereas slightly influences the growth of human normal liver cell line L-02. When treated with GFPS1b, SGC-7901 cells showed typical apoptotic morphological features such as the loss of villus and appearance of apoptotic bodies on the cell surface, volume reduction, and chromatin condensation, by scanning electron microscopy (SEM) and fluorescent microscopy (Hoechst 33342). The results of flow cytometry analysis and annexin V-PI assay showed that the SGC-7901 cell cycle was arrested in the G 2/M phase, the subdiploid peak of DNA characteristic of apoptotic was also observed, and the apoptosis ratio was about 15.08%. DNA isolated from SGC-7901 cells cultured with GFPS1b showed a typical DNA ‘ladders’ of apoptosis in agarose gel electrophoresis. Further investigation results showed that the apoptotic machinery of SGC-7901 induced by GFPS1b was associated with drop in mitochondrial trans-membrane potential, upregulation of Bax, downregulation of Bcl-2, and activation of caspase-3. Our finding suggests that GFPS1b could suppress SGC-7901 cell growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.

The Effect of δ-Elemene on Hela Cell Lines by Apoptosis Induction

This study was designed to investigate the apoptosis-inducing activity of delta-elemene on Hela cells in vitro. MTT assay and Hoechst 33258/PI fluorescence microscopy were used for this investigation. Apoptosis was further confirmed and quantified by DNA fragmentation ELISA, Annexin V (AnV) binding of externalized phosphatidylserine and the mitochondrial probe JC-1 using flow cytometry. Generation of reactive oxygen species (ROS) was detected using CM-H2DCFDA. Western blots analysis was performed using antibodies against the pro-caspase-3, or PRAP (Poly (ADP-ribose) polymerase). The results showed that delta-elemene exhibited a marked antiproliferative effect on Hela cells in dose- and time-dependent manners, and had little inhibition to normal human liver cell line WRL-68. It was demonstrated that delta-elemene was capable of inducing DNA fragmentation in a dose- and time-dependent manner. AnV positivity and the disturbance of the polarized mitochondrial transmembrane potential (Deltapsim) suggested that delta-elemene induced apoptotic death of Hela cells. Western blot analysis demonstrated that delta-elemene activated the caspase-signaling pathway, leading to the proteolysis conversion of pro-caspase-3 to activate caspase-3, and the subsequent cleavage of the caspase substrate PARP. Further, it was noted that the apoptotic effect of delta-elemene could be attenuated by L-Glutathione (GSH) or z-DEVD-fmk. It suggested that the increase in ROS generation might be involved in the mechanism of delta-elemene induced cell apoptosis.

Knockdown of c-Met by adenovirus-delivered small interfering RNA inhibits hepatocellular carcinoma growth in vitro and in vivo

c-Met is highly expressed and constitutively activated in various human tumors. We employed adenovirus-mediated RNA interference technique to knock down c-Met expression in hepatocellular carcinoma cells and observed its effects on hepatocellular carcinoma cell growth in vitro and in vivo. Among the five hepatocellular carcinoma and one normal human liver cell lines we analyzed, c-Met was highly expressed and constitutively tyrosine phosphorylated in only MHCC97-L and HCCLM3 hepatocellular carcinoma cells. Knockdown of c-Met could inhibit MHCC97-L cells proliferation by arresting cells at G0-G1 phase. Soft agar colony formation assay indicated that the colony forming ability of MHCC97-L cells decreased by approximately 70% after adenovirus AdH1-small interfering RNA (siRNA)/met infection. In vivo experiments showed that adenovirus AdH1-siRNA/met inhibited the tumorigenicity of MHCC97-L cells and significantly suppressed tumor growth when injected directly into tumors. These results suggest that knockdown of c-Met by adenovirus-delivered siRNA may be a potential therapeutic strategy for treatment of hepatocellular carcinoma in which c-Met is overexpressed.

Ganoderic acid produced from submerged culture of Ganoderma lucidum induces cell cycle arrest and cytotoxicity in human hepatoma cell line BEL7402

Ganoderic acid (GA), produced by submerged culture of Ganoderma lucidum, at 500 microg/ml, caused nearly a 70% inhibition of the growth of human hepatoma cell line BEL7402 but not of a normal human liver cell line L02. Flow cytometry analyses showed that GA blocked the BEL7402 cell cycle at the transition from G(1 )to S phase.

Lectin-mediated cytotoxicity and specificity of 5-fluorouracil conjugated with peanut agglutinin (5-Fu-PNA) in vitro

In order to take advantage of the biorecognition between lectin and carbohydrate for targeted drug delivery, the lectin of peanut (Arachis hypogaea) agglutinin (PNA) was coupled by fixing its amino groups to the carbodiimide-activated carboxylic groups of 5-fluorouracil (5-Fu) derivative (N1-substituted 5-Fu acetate) to form 5-Fu-PNA conjugate. When the coupling reaction was carried out in the presence of d-galactose (d-gal, specific sugar for PNA), the affinity of PNA was maintained after its coupling to N1-substituted 5-Fu acetate, which was confirmed by the result of the haemagglutination test. Otherwise, PNA would lose its affinity after the cross-linking reaction. The cytotoxicity, specificity and selectivity of 5-Fu-PNA were examined on the human colorectal cancer cell line LoVo and the human normal liver cell line Chang using MTT assay. Compared with free drug, the active conjugate, which maintained the affinity of lectin, had similar cytotoxic effect on LoVo cells with much lower cytotoxicity on Chang cells (p < 0.05). On the other hand, lower cytotoxic effects on LoVo cells were observed for the non-active conjugate even at higher drug concentrations. The cytotoxic effect of conjugate was specific because only the active conjugate could inhibit the growth of LoVo cells in a dose- and time-dependent manner as that of the free drug. The achieved results indicate the significance to maintain the affinity of lectin for lectin-mediated cytotoxicity. Still, the potential of 5-Fu-PNA conjugate as a targeting agent for colorectal cancer needs to be further investigated in vivo.

Human hepatitis B virus X protein promotes cell proliferation and inhibits cell apoptosis through interacting with a serine protease Hepsin

The X protein of human hepatitis B virus (HBV) acts as an indirect transcriptional transactivator to regulate the expression of many viral and cellular genes as well as playing a critical role in the development of hepatocellular carcinoma. While the biological importance of HBx has been well established, the cellular and molecular bases of its function remain largely undefined. In this study, we isolated a new HBV field strain from a patient with chronic viral infection. The X protein encoded by this virus was used as a bait protein for screening a human liver cDNA library using a yeast two-hybrid system. Several cell proteins were identified as new HBx interacting partners, including a transmembrane serine protease, Hepsin. Direct interaction between HBx and Hepsin proteins was confirmed by in vitro and in vivo co-immunoprecipitation assays. HBx also co-localized with Hepsin in human cells as determined by confocal immunofluorescence microscopy. The interaction between HBx and Hepsin protein appeared to play a role in both promoting cell proliferation and blocking apoptosis in human liver tumor cell and normal liver cell lines. In addition, the complex of HBx and Hepsin promoted the expression of HBeAg in Hep G2.2.1.5 cells indicating that the association of these two proteins stimulated viral replication.

Down-Regulation of Growth Arrest DNA Damage-Inducible Gene 45β Expression Is Associated with Human Hepatocellular Carcinoma

In this study, we describe the growth arrest DNA damage-inducible gene 45beta (GADD45beta), whose expression was significantly down-regulated in the hepatocellular carcinoma (HCC) microarray study and confirmed by Northern blot analysis. The results suggested that expression of GADD45beta was decreased in human liver cancer cell lines HepG2 and Hep3B, but not in normal human embryonic liver cell line CL-48 or normal liver tissue. Histochemistry study and real-time PCR further confirmed that GADD45beta staining in HCC was significantly decreased when compared to surrounding non-neoplastic liver tissue. In further studies of multiple human cancer tissues, GADD45beta strongly stained tissues such as colon cancer, breast cancer, prostate cancer, squamous cell cancer, lymphoma, and leiomyosarcoma, suggesting that the decreased expression of GADD45beta is specific to HCC. Eighty-five cases of primary HCC were further examined by immunohistochemistry and statistical analyses demonstrated that HCC scored lower than matched non-neoplastic liver tissues consistently and significantly. No staining occurred in 12.94% of HCC cases (score = 0, n = 11); 42.35% had weak staining (score = 1, n = 36); 27.06% had moderate staining (score = 2, n = 23); and 17.65% had staining as strong as normal tissue (score = 3, n = 15). Overall, surrounding non-neoplastic liver tissue was highly positive for GADD45beta compared to adjacent neoplastic liver tissues (P < 0.01). We further observed that down-regulation of GADD45beta expression was strongly correlated with differentiation (P < 0.01) and high nuclear grade (P < 0.01). Moreover, we found that expression of GADD45beta was inversely correlated to the presence of mutant p53 in HCC tissue (P < 0.05). Thus, the results of our study suggest that GADD45beta, which is down-regulated in most cases of HCC, remains an ideal candidate for development as a molecular marker in the diagnosis of HCC and as a potential therapeutic target.

Triterpene-enriched extracts from Ganoderma lucidum inhibit growth of hepatoma cells via suppressing protein kinase C, activating mitogen-activated protein kinases and G2-phase cell cycle arrest

The medicinal mushroom Ganoderma lucidum (G. lucidum) has been used in the Orient for the prevention and treatment of various diseases including cancer. Except for the immune enhancing properties of its polysaccharide constituent, very little is known about the anticancer activity of another major constituent, triterpenes. In this report, we studied the anticancer mechanism of triterpene-enriched extracts from G. lucidum. The triterpene-enriched fraction, WEES-G6, was prepared from mycelia of G. lucidum by sequential hot water extraction, removal of ethanol-insoluble polysaccharides and then gel-filtration chromatography. We found that WEES-G6 inhibited growth of human hepatoma Huh-7 cells, but not Chang liver cells, a normal human liver cell line. Treatment with WEES-G6 caused a rapid decrease in the activity of cell growth regulative protein, PKC, and the activation of JNK and p38 MAP kinases. The changes in these molecules resulted in a prolonged G2 cell cycle phase and strong growth inhibition. None of these effects were seen in the normal liver cells. Our findings suggest that the triterpenes contained in G. lucidum are potential anticancer agents.