Dorsomorphin attenuates ABCG2-mediated multidrug resistance in colorectal cancer.

Colorectal cancer is a common malignant tumor with high mortality, for which chemotherapy resistance is one of the main reasons. The high expression of ABCG2 in the cancer cells and expulsion of anticancer drugs directly cause multidrug resistance (MDR). Therefore, the development of new ABCG2 inhibitors that block the active causes of MDR may provide a strategy for the treatment of colorectal cancer. In this study, we find that dorsomorphin (also known as compound C or BML-275) potently inhibits the transporter activity of ABCG2, thereby preserving the chemotherapeutic agents mitoxantrone and doxorubicin to antagonize MDR in ABCG2-overexpressing colorectal cancer cells. Additionally, dorsomorphin does not alter ABCG2 protein expression. The results of molecular docking studies show that dorsomorphin is bound stably to the ABCG2-binding pocket, suggesting that dorsomorphin is a potent ABCG2 inhibitor that attenuates ABCG2-mediated MDR in colorectal cancer.

Successful endoscopic drainage of malignant obstructive jaundice in patients with situs inversus totalis: Two cases report.

INTRODUCTION AND IMPORTANCE: Although endoscopic techniques in situs inversus totalis (SIT) have been reported, endoscopic retrograde cholangiopancreatography (ERCP) in patients with situs inversus totalis (SIT) remains difficult to every hepatobiliary surgeon. To investigate the differences of each position, ERCP was used to perform through two different body positions. CASE PRESENTATION: Herein we report a 63-year-old woman presented with epigastric pain for 2 months and jaundice for 7 days and a 51-year-old man with presented jaundice for 7 days. Preoperative examination revealed situs inversus totalis and gallbladder carcinoma with diffuse dilatation of the biliary tree. ERCP was used to perform by using two different body positions. In addition, the ERCP combined with percutaneous transhepatic cholangial drainage (PTCD) was performed in the second patient. CLINICAL DISCUSSION: The different endoscopic approaches are used in different positions, the endoscopist should be familiar with mirror symmetrical anatomy. We argue that the prone position has a higher surgical success rate and ERCP combined with PTCD will be easier in SIT patients. CONCLUSION: ERCP in SIT patients is generally safe and it will be easier by combining with PTCD.

Correction to: Exosomal miR-21 regulates the TETs/PTENp1/PTEN pathway to promote hepatocellular carcinoma growth.

Following the publication of article [1], the authors found that the images of Transwell Matrigel invasion (Fig. 7d) are incorrect.

Exosomal miR-21 regulates the TETs/PTENp1/PTEN pathway to promote hepatocellular carcinoma growth.

BACKGROUND: As an important means of communication, exosomes play an important role in the development of hepatocellular carcinoma (HCC). METHODS: Bioinformatics analysis, dual-luciferase reporter assays, methylation-specific quantitative PCR, and ChIP-PCR analysis were used to gain insight into the underlying mechanism of miR-21 in HCC. RESULTS: The detection of miRNAs in exosomes of HCC showed that miR-21 expression in exosomes was positively correlated with the expression level of miR-21 in cells and negatively correlated with the expression of its target genes PTEN, PTENp1 and TETs. HCC cell-derived exosomes could increase miR-21 and p-Akt expression in HCC cells and downregulate the expression of PTEN, PTENp1 and TETs. MiR-21 inhibitors or PTENp1 overexpression vectors could weaken the effect of the abovementioned exosomes and simultaneously weaken their role in promoting cell proliferation and migration and inhibiting apoptosis. Further studies showed that miR-21 not only directly regulated the expression of PTEN, PTENp1 and TETs but also increased the methylation level of the PTENp1 promoter by regulating the expression of TETs, thereby inhibiting the expression of PTENp1 and further downregulating the expression of PTEN. CONCLUSIONS: Exosomal miR-21 can regulate the expression of the tumor suppressor genes PTEN and PTENp1 in various ways and affect the growth of HCC cells.

Peroxisome proliferator-activated receptor-γ inhibits pancreatic cancer cell invasion and metastasis via regulating MMP-2 expression through PTEN.

The invasive and metastatic behavior of pancreatic cancer is associated with a poor prognosis. Therefore, understanding the molecular mechanisms underlying the invasion and metastasis of pancreatic cancer has important application values theoretically and clinically. In previous years, with increasing studies focusing on tumor pathogenesis, it has been revealed that peroxisome proliferator­activated receptor­Î³ (PPARγ) and phosphatase and tensin homolog (PTEN) are closely associated with the occurrence and development of pancreatic cancer. Thus, in the present study, a scratch wound assay, western blotting and transwell assays were used to investigate their function. The scratch wound assay demonstrated that treatment with the PPARγ ligand rosiglitazone (RGZ) could reduce the movement and migration of pancreatic cancer cells. Western blotting results indicated that while RGZ inhibited the expression of matrix metalloproteinase (MMP)­2, PPARγ inhibitors promoted MMP­2 expression. However, PPARγ ligands and inhibitors did not affect the expression of MMP­9. Further investigation indicated that the regulation of MMP­2 by PPARγ activation occurred through PTEN. In addition, PPARγ activation promoted PTEN expression, thereby inhibiting the expression of MMP­2. Subsequent transwell experiments demonstrated that RGZ treatment significantly inhibited the invasiveness of pancreatic cancer cells and the inhibitory effect of RGZ was completely reversed by simultaneous transfection of the MMP­2­overexpressing vector, which increased the invasiveness of pancreatic cancer cells. Therefore, PPARγ activation can activate PTEN expression, thereby suppressing the expression of MMP­2 and hence inhibiting the invasion and metastasis of pancreatic cancer cells.

Activation of peroxisome proliferator-activated receptor-γ (PPARγ) inhibits hepatoma cell growth via downregulation of SEPT2 expression.

Hepatocellular carcinoma (HCC) is a malignant tumor with poor prognosis and low therapeutic efficacy. Recent studies have demonstrated the therapeutic prospect of peroxisome proliferator-activated receptor-γ (PPARγ) cancer angiogenesis. However, the action mechanisms remain elusive. In the present study, by using mass spectrometry, we found that PPARγ ligand rosiglitazone (RGZ) could regulate HCC cell growth by influencing various downstream factors and pathways. Among the altered proteins, septin 2 (SEPT2) was found to exhibit oncogenic function. PPARγ overexpression could inhibit the expression of SEPT2, thus blocking the promoting effects of SEPT2 on HCC cell proliferation, invasion and its inhibitory effect on cell apoptosis. Further studies also indicated that SEPT2 promoted HCC cell growth via upregulation of matrix metalloproteinase (MMP)-2 and -9, and simultaneously inhibited the cleavage of caspase-3, -7, and -9. Interestingly, the effects of SEPT2 on the above factors could be suppressed by PPARγ overexpression, suggesting that PPARγ could inhibit HCC cell growth via regulating the expression and blocking the oncogenic function of SEPT2. Taken together, these results provide new evidence for the action mechanisms of PPARγ in carcinogenesis of HCC, and upon further investigation, PPARγ could be developed as a new target for the treatment of liver cancer.

Gli2 silencing enhances TRAIL-induced apoptosis and reduces tumor growth in human hepatoma cells in vivo.

Our previous studies have showed that Gli2 played a predominant role in proliferation and apoptosis resistance to TRAIL in hepatoma cells. The purpose of this study was to explore whether Gli2 silencing enhances efficiency of TRAIL for hepatoma in vivo. SMMC-7721-shRNA cells were implanted subcutaneously into nude mices and TRAIL was injected into the peritoneal space. TUNEL assay was used to detect apoptosis of tumor cells. The expression of Gli2, c-FLIPL, c-FLIPS, and Bcl-2 protein was determined by immunohistochemistry, respectively. Apoptosis and the level of caspases proteins in SMMC-7721 and HepG2 cells were detected by Flow cytometry and Western blot. Transcriptional activity of c-FLIP induced by Gli2 was measured by luciferase reporter gene assay. The results showed that lower volumes and weights of tumor were found in mice xenografted with SMMC-7721-shRNA cells as compared with control cells in the presence of TRAIL (P < 0.05). TUNEL assay showed significantly higher apoptosis index (AI) in the SMMC-7721-shRNA group than in the control groups (P < 0.05). There were remarkable positive correlations between Gli2 and c-FLIPL, c-FLIPS, Bcl-2 protein expression. Over-expression of c-FLIP or Bcl-2 in HepG2 cells attenuated TRAIL-induced apoptosis via suppression of caspase-8 or caspase-9 activity, respectively. Luciferase reporter gene assay found a regulatory sequence by which Gli2 activated transcription between -1007 to -244 in the c-FLIP promoter region. This study demonstrates that Gli2 showed regulatory activity on transcription of c-FLIP gene, and Gli2 silencing enhances TRAIL-induced apoptosis via down-regulation of c-FLIP and Bcl-2 in human hepatoma cells in vivo.

MicroRNA-1269 promotes proliferation in human hepatocellular carcinoma via downregulation of FOXO1.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignancies and a major cause of cancer-related mortality in the world. MicroRNAs (miRNAs) are small, noncoding RNAs that play essential roles in various stages during cancer progression. The aim of the current study was to elucidate the role of miR-1269 in the pathogenesis of HCC. METHODS: The expression of miR-1269 in HCC cells and tissues were determined by Real-time PCR analysis. Cell viability, colony formation and anchorage-independent growth ability assays were performed to examine cell proliferative capacity and tumorigenicity. Flow cytometry analysis was conducted to determine cell cycle progression. The expression of p21, CyclinD1, phosphorylated Rb, Rb and FOXO1 were examined by Western blotting analysis. Luciferase assay was used to determine whether FOXO1 is the direct target of miR-1269. RESULTS: miR-1269 was upregulated in HCC cells and tissues. Ectopic miR-1269 expression promoted, but inhibition of miR-1269 reduced, proliferation, tumorigenicity and cell cycle progression of HCC cells. Furthermore, we demonstrated that FOXO1 was a direct target of miR-1269. Suppression of FOXO1 by miR-1269 was associated with dysregulation of p21, cyclin D1, phosphorylated Rb and Ki67 expression, thereby playing an essential role in the growth of HCC cells. CONCLUSIONS: Our study indicated that overexpression of miR-1269 promotes cell proliferation in HCC through directly suppressing FOXO1, and functions as an oncomiR in HCC.

Green tea polyphenol epigallocatechin-3-gallate enhances 5-fluorouracil-induced cell growth inhibition of hepatocellular carcinoma cells.

AIM: 5-Fluorouracil (5-FU) is one of the most commonly used chemotherapeutic drugs. Resistance to 5-FU is a major cause of chemotherapy failure in advanced-stage hepatocellular carcinoma (HCC). Green tea polyphenol Epigallocatechin-3-gallate (EGCG) plays a critical role in growth inhibition and apoptotic induction in HCC cell lines. The aim of this study is to investigate whether EGCG can enhance 5-FU-induced cell growth inhibition and to explore its potential mechanisms. METHODS: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate cell growth. Western blotting analysis was performed to detect the proteins expression in Hep3B cells. Small interfering RNA was used to suppress cyclooxygenase-2 (COX-2) expression. Furthermore, enzyme linked immunosorbent assay was used to test the prostaglandin E(2) (PGE(2) ) production in cell cultures. RESULTS: Epigallocatechin-3-gallate augmented the anti-tumor effect of 5-FU in Hep3B cells. Significant difference was observed between the treated groups and the control group (P < 0.05). EGCG (its concentrations at over 5 µmol/L) combined with 5-FU presented a synergic effect. Furthermore, the combination of EGCG and 5-FU abrogated the COX-2 overexpression and PGE(2) secretion induced by 5-FU. The upregulation of COX-2 expression decreased the phosphorylation of Akt (Thr(308) ) expression. These appeared to be followed by the AMPK hyperactivation. CONCLUSION: Epigallocatechin-3-gallate sensitizes HCC cells to 5-FU antitumor activity, and the combination of EGCG and 5-FU exhibits synergism in chemo-resistant cancer cells. The results suggest potential novel therapies for the treatment of advanced-stage liver cancer.

Expression of sonic hedgehog signaling components in hepatocellular carcinoma and cyclopamine-induced apoptosis through Bcl-2 downregulation in vitro.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Aberrant activation of sonic hedgehog (Shh) signaling pathway plays important roles in tumorigenesis and progression of several tumors. Cyclopamine, an important inhibitor of Shh signaling pathway, can induce cell apoptosis. However, the mechanisms underlying cyclopamine-induced apoptosis are not well understood. The aim of this study is to determine the expression of the Shh signaling pathway components in HCC and to investigate the mechanisms underlying cyclopamine-induced apoptosis in HCC cells. METHODS: Shh signaling components (Shh, Ptch, Smo and Gli-1) expression levels were evaluated by immunohistochemistry on tissue microarrays containing 98 HCCs with paired adjacent noncancerous liver tissues. The relationships between sonic hedgehog signal pathway and clinicopathological factors were analyzed in HCC. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis was detected by flow cytometry. mRNA and protein levels were analyzed by RT-PCR and Western blot, respectively. RESULTS: Shh, Ptch, Smo and Gli-1 were overexpressed in HCC tissues compared with paired adjacent noncancerous liver tissue. Activated Shh signaling pathway was associated with tumor size, capsular invasion and vascular invasion in HCC. Cyclopamine remarkably decreased cell viability, induced apoptosis and downregulated Bcl-2 expression in HCC cells. CONCLUSIONS: Shh signaling pathway plays an important role in HCC tumorigenesis and progression, indicating that Shh signaling pathway is a potential therapeutic target for HCC. Cyclopamine induces apoptosis through downregulating Bcl-2 in HCC.

Rosiglitazone enhances 5-fluorouracil-induced cell growth inhibition in hepatocellular carcinoma cell line Hep3B.

BACKGROUND AND OBJECTIVE: Rosiglitazone is a peroxisome proliferators-activated receptor gamma (PPARgamma) ligand, which inhibits tumor growth by activating PPARgamma signaling pathways. Fluorouracil (5-FU) is one of the commonly used chemotherapeutic drugs. However, patients develop drug resistance of 5-FU over time. The aim of this study was to investigate whether rosiglitazone can enhance 5-FU-induced cell growth inhibition and to explore its potential mechanisms. METHODS: Cell viability was measured using MTT assay. Protein expression levels were detected by Western blot analysis. Small interference RNA was utilized to knockout PPARgamma and PTEN in Hep3B cells. RESULTS: After 48 h of treatment with 10, 20, and 40 µmol/L rosiglitazone, the viability of Hep3B cells was (78.0 ± 2.7)%, (37.3 ± 8.1)%, and (19.8 ± 2.2)%, respectively (compared with control group, P values were all < 0.001). After 48 h of treatment with 10 µmol/L 5-FU, the viability of Hep3B cells was about (82.6 ± 3.9)%. When cells were treated with 10 µmol/L 5-FU in combination with either 10, 20 or 40 µmol/L rosiglitazone, the cell viability was (51.6 ± 5.4)%, (14.8 ± 4.2)%, and (8.5 ± 0.9)%, with corresponding q value of 1.36, 1.23, and 1.19, respectively. These data suggested that the two drugs had synergic effect in inhibiting Hep3B cell growth, which was further confirmed in an in vivo mice model. Subsequent investigations showed that rosiglitazone activated PPARgamma signaling pathways and increased the expression of PTEN. CONCLUSIONS: Rosiglitazone enhances 5-FU-induced cell growth inhibition of Hep3B cells.

MicroRNA-9 reduces cell invasion and E-cadherin secretion in SK-Hep-1 cell.

MicroRNAs (miRNAs) are an abundant class of short noncoding RNAs that can posttranscriptionally regulate gene expression in animals. They are also involved in cancer initiation and progression, and their expression profiles serve as phenotypic signatures of different cancers. The roles played by microRNAs specifically in "micromanagement of metastasis" has been addressed only recently. The molecular mechanisms of hepatocellular carcinoma (HCC) metastasis are still poorly understood. Recent evidence implies genetic determinants of cancer metastasis. Because gene expression signature significantly differs between primary metastasis-free HCC and primary HCC with intrahepatic metastases, miRNA expression in those primary HCC may change correspondingly. The 28 up-regulated miRNAs, part of the reported miRNA profiles of HCC, were compared in primary HCC with or without metastases. Only eight miRNAs were found to be significantly up-regulated in primary HCC with metastases while miR-9 had the highest hold change. miR-9 was highly expressed in SK-Hep-1 cell when compared with other hepatoma cell lines and downregulation of miR-9 reduced SK-Hep-1 cell invasion. E-cadherin, a tumor invasion suppressor in HCC, was found to be a putative gene target of miR-9. E-cadherin was up-regulated by miR-9 inhibitor. The findings suggest miR-9 could be involved in HCC metastasis.

Hematoporphyrin derivative-mediated photodynamic therapy inhibits tumor growth in human cholangiocarcinoma in vitro and in vivo.

AIM: To investigate the effects of hematoporphyrin derivative-mediated photodynamic therapy (HPD-PDT) on cell growth in human cholangiocarcinoma in vitro and in vivo, as well as the underlying mechanisms of these effects. METHODS: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate growth status of human cholangiocarcinoma cell line (QBC939). Hoechst 33258 staining and flow cytometry assays were applied to determine cell apoptosis. Western blotting analysis was performed to detect the release of cytochrome c in QBC939 cells, and caspases enzymatic assay was used to investigate the activation of caspase-3, -8, and -9. Further, tumor growth after subcutaneous implantation of QBC939 cells in nude mice was monitored. RESULTS: HPD-PDT inhibits QBC939 cell growth via cell apoptosis in vitro, and initiates cell mitochondria apoptosis pathway by the release of cytochrome c and the activation of caspase-9 and -3. Moreover, HPD-PDT also inhibits subcutaneous tumor growth of QBC939 cells and reduces tumor cell mitosis in nude mice. CONCLUSION: HPD-PDT inhibits tumor growth of human cholangiocarcinoma, suggesting that HPD-PDT is useful in cholangiocarcinoma therapy.

Rosiglitazone sensitizes hepatocellular carcinoma cell lines to 5-fluorouracil antitumor activity through activation of the PPARgamma signaling pathway.

AIM: Resistance to 5-fluorouracil (5-FU) is a major cause of chemotherapy failure in advanced hepatocellular carcinoma (HCC). Rosiglitazone, a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, has a crucial role in growth inhibition and induction of apoptosis in several carcinoma cell lines. In this study, we examine rosiglitazone-induced sensitization of HCC cell lines (BEL-7402 and Huh-7 cells) to 5-FU. METHODS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate cell viability. Western blotting analysis was performed to detect the protein expression (PPARgamma, PTEN, and COX-2) in BEL-7402 cells. Immunohistochemistry staining was used to examine the expression of PTEN in 100 advanced HCC tissues and paracancerous tissues. In addition, small interfering RNA was used to suppress PPARgamma, PTEN, and COX-2 expression. RESULTS: Rosiglitazone facilitates the anti-tumor effect of 5-FU in HCC cell lines, which is mediated by the PPARgamma signaling pathway. Activation of PPARgamma by rosiglitazone increases PTEN expression and decreases COX-2 expression. Since distribution of PTEN in HCC tissues is significantly decreased compared with the paracancerous tissue, over-expression of PTEN by rosiglitazone enhances 5-FU-inhibited cell growth of HCC. Moreover, down-regulation of COX-2 is implicated in the synergistic effect of 5-FU. CONCLUSION: Rosiglitazone sensitizes hepatocellular carcinoma cell lines to 5-FU antitumor activity through the activation of PPARgamma. The results suggest potential novel therapies for the treatment of advanced liver cancer.

Bead-based microarray analysis of microRNA expression in hepatocellular carcinoma: miR-338 is downregulated.

AIM: Recent studies have underlined causative links between microRNA (miRNA) deregulation and cancer development. However, the relevance of abnormally expressed miRNA to tumor biology has not been well understood in hepatocellular carcinoma (HCC). METHODS: A bead-based miRNA expression profiling method was performed on 20 pairs of surgically removed HCC and adjacent non-tumorous tissue (NT). Special miR-338 downregulations and miR-338 associated with clinical characteristics was validated in an extended samples set of 36 paired HCC and adjacent non-tumorous liver tissues by real-time reverse transcription polymerase chain reaction (RT-PCR) analysis. RESULTS: Out of our bead-based microarray data, 12 upregulated and 19 downregulated miRNA were found to be associated with HCC. Further characterization of miRNA-338, in which 20 pairs of the samples were clustered clearly into two groups according to expression of miR-338, revealed that the level of miR-338 expression can be associated with clinical aggressiveness, such as, tumor size, tumor-node-metastasis stage, vascular invasion and intrahepatic metastasis. These results were validated by real-time RT-PCR analysis. CONCLUSION: Our study suggests that miRNA expression could have relevance to the clinical behavior of HCC and that the bead-based miRNA expression profiling method might be a suitable system to assay miRNA expression in large-scale diagnostic trails.

Involvement of PI3K/PTEN/AKT/mTOR pathway in invasion and metastasis in hepatocellular carcinoma: Association with MMP-9.

AIM: To investigate the status of Phosphatidylinositol 3-kinase (PI3K)/PTEN/AKT/mammalian target of rapamycin (mTOR) pathway and its correlation with clinicopathological features and matrix metalloproteinase-2, -9 (MMP-2, 9) in human hepatocellular carcinoma (HCC). METHODS: PTEN, Phosphorylated AKT (p-AKT), Phosphorylated mTOR (p-mTOR), MMP-2, MMP-9 and Ki-67 expression levels were evaluated by immunohistochemistry on tissue microarrays containing 200 HCCs with paired adjacent non-cancerous liver tissues. PTEN, MMP-2 and MMP-9 mRNA levels were determined by real-time RT-PCR in 36 HCCs. The relationships between PI3K/PTEN/AKT/mTOR pathway and clinicopathological factors and MMP-2, 9 were analyzed in HCC. RESULTS: In HCC, PTEN loss and overexpression of p-AKT and p-mTOR were associated with tumor grade, intrahepatic metastasis, vascular invasion, TNM stage and high Ki-67 labeling index (P < 0.05). PTEN loss was correlated with p-AKT, p-mTOR and MMP-9 overexpression. Furthermore, PTEN and MMP-2, 9 mRNA levels were down-regulated and up-regulated in HCC compared with paired non-cancerous liver tissues, respectively (P < 0.01). PTEN, MMP-2 and MMP-9 mRNA levels were correlated with tumor stage and metastasis. There was an inverse correlation between PTEN and MMP-9 mRNA expression. However, PI3K/PTEN/AKT/mTOR pathway was not correlated with MMP-2. CONCLUSIONS: PI3K/PTEN/AKT/mTOR pathway, which is activated in HCC, is involved in invasion and metastasis through up-regulating MMP-9 in HCC.

[Epigallocatechin-3-gallate induces apoptosis in human hepatocellular carcinoma cells].

OBJECTIVE: To investigate the effects of epigallocatechin-3-gallate (EGCG) on human hepatocellular carcinoma (HCC) cells and mechanism thereof. METHOD: Human HCC cells of the lines HepG2 and SMMC-7721 were cultured and treated with of EGCG of the concentrations of 6.25, 12.5, 25, 50, 100, 200, and 400 microg/ml respectively for 24 h and 48 h. The cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Trypan blue staining was used to count the cells. Flow cytometry was conducted to detect the cell apoptosis. The protein levels of Bcl-2, an anti-apoptosis factor, and cyclooxygenase-2 (COX-2), an up-regulator of Bcl-2. The activities of caspase-9 and caspase-3 hat promote the apoptosis of HCC cells, were measured using colorimetric method. RT-PCR was used to detect the mRNA expression of COX-2 and Bcl-2 family. RESULTS: The viabilities of the HepG2 and SMMC-7721 cells treated with EGCG of the concentrations of 50 - 400 microg/ml for 48 h reduced to 93.8% +/- 2.8%, 62.3% +/- 5.4%, 33.9% +/- 2.5%, and 17.6% +/- 3.2% respectively, all significantly lower than that of the control group [(100.0% +/- 2.8%), all P < 0.05]; and the viabilities of the SMMC-772 cells treated with EGCG of the concentrations of 50 - 400 microg/ml for 48 h reduced to 49.6% +/- 3.5%, 30.3% +/- 3.8%, 17.7% +/- 2.2%, and 13.0% +/- 2.5% respectively, all significantly lower than that of the control group [(100.0% +/- 0.8%), all P < 0.05]. After treatment with 100 microg/ml EGCG for 24 h, 48 h, 72 h, and 96 h, the live HepG2 cell numbers were (8.0 +/- 1.5), (22.0 +/- 3.1), (37.0 +/- 5.4), and (61.0 +/- 8.7) 10(4) respectively, all significantly lower than those of the control cells [(15.0 +/- 2.5), (45.0 +/- 5.3), (86.0 +/- 11.0), and (210.0 +/- 23.0) 10(4) respectively, all P < 0.05]; and the live SMMC-7721 cell numbers were (7.0 +/- 2.2), (13.0 +/- 2.5), (20.0 +/- 3.7), and (31.0 +/- 4.0) 10(4) respectively, all significantly lower than those of the control cells [(15.0 +/- 2.5), (45.0 +/- 5.3), (86.0 +/- 11.0), and (210.0 +/- 23.0) 10(4) respectively, all P < 0.05]. The apoptotic rates of HepG2 cells treated with EGCG of the concentrations of 50, 100, and 200 microg/ml for 12 h were 8.7% +/- 0.4%, 18.1% +/- 1.1%, and 22.1% +/- 1.8% respectively, all significantly higher than that of the control group (3.3% +/- 0.3%, P < 0.05); and the apoptotic rates of SMMC-7721 cells were 5.9% +/- 0.3%, 7.8% +/- 0.6%, and 12.2% +/- 0.8% respectively, all significantly higher than that of the control group (3.7% +/- 0.4%, P < 0.05). After treatment with EGCG of the concentrations of 100 and 200 microg/ml for 12 h, the caspase-9 activities of the HepG2 cells increased to (1.8 +/- 0.4) and (2.5 +/- 0.4) respectively, both significantly higher than that of the control group (1.0 +/- 0.1, both P < 0.05); and the caspase-3 activities of the HepG2 cells increased to (2.0 +/- 0.4) and (2.8 +/- 0.5) respectively, both significantly higher than that of the control group (1.0 +/- 0.2, P < 0.05) ; and the caspase-9 activities of the SMMC-7721 cells increased to (1.7 +/- 0.4) and (2.5 +/- 0.4), both significantly higher than that of the control group (1.0 +/- 0.1, both P < 0.05), and the caspase-3 activities of the SMMC-7721 cells increased to (1.9 +/- 0.4) and (2.6 +/- 0.3) respectively, both significantly higher than that of the control group [ (1.0 +/- 0.2), both P < 0.05]. When the concentration of EGCG was over 200microg/ml, it down-regulated the expression of COX-2 and Bcl-2 in both cell lines, however, EGCG resulted in no significant changes of Bcl-xl, Bax, Bad, and Bid. CONCLUSION: EGCG induces apoptosis in HCC cells through down-regulation of COX-2 and Bcl-2 and consequently activating caspase-9 and caspase-3.

Gli-1 siRNA induced apoptosis in Huh7 cells.

AIM: To investigate the effects of Gli-1 small interference RNA (siRNA) on Huh7 cells, and the change of Bcl-2 expression in Huh7 cells. METHODS: Human hepatocellular carcinoma cells Huh7 were used. Cell viability was analyzed by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The expressions of Gli-1 and Bcl-2 family members were detected by RT-PCR and Western blot. Apoptosis was detected by Flow cytometry using propidium iodide, measured by Hoechst 33258 staining using Advanced Fluorescence Microscopy and caspase-3 enzymatic assay. Cell growth was analyzed after treatment with Gli-1 siRNA and 5-fluorouracil (5-Fu). RESULTS: Inhibition of Gli-1 mRNA in Huh7 cells through Gli-1 siRNA reduced cell viability. Gli-1 siRNA treatment also induced apoptosis by three criteria, increase in the sub-G1 cell cycle fraction, nuclear condensation, a morphologic change typical of apoptosis, and activation of caspase-3. Gli-1 siRNA was also able to down-regulate Bcl-2. However, Gli-1 siRNA resulted in no significant changes in Bcl-xl, Bax, Bad, and Bid. Furthermore, Gli-1 siRNA increased the cytotoxic effect of 5-Fu on Huh7 cell. CONCLUSION: Down-regulation of Bcl-2 plays an important role in apoptosis induced by Gli-1 siRNA in HCC cells. Combination Gli-1 siRNA with chemotherapeutic drug could represent a more promising strategy against HCC. The effects of the strategies need further investigation in vivo and may have potential clinical application.

Establishment and characterization of a human cholangiocarcinoma cell line.

Cholangiocarcinoma (CC) is a rare malignant tumor arising from the biliary tract. The disease is notoriously difficult to diagnose and is usually fatal due to its late clinical presentation and the lack of effective non-surgical therapeutic strategies. To date, little is known about the cancer biology of the disease and the establishment and characterization of only a few CC cell lines have been reported. We report here the establishment of a new human cancer cell line, HKGZ-CC, from a moderate to poorly differentiated intrahepatic bile duct carcinoma from a Chinese patient. Morphological characteristics, growth kinetics, ability to grow on anchorage-independent soft agar, tumorigenicity in nude mice and cytogenetic features of the cell line were investigated. Chromosome banding karyotype and comparative genomic hybridization analyses revealed chromosomal changes in 1pter-p31, 1q31-qter, 3q, 8q21-qter, 9pter-9q34, 10, 13q21-qter and X. This newly established cell line should serve as a useful model for studying the molecular pathogenesis of CC.

Upregulation of PTEN involved in rosiglitazone-induced apoptosis in human hepatocellular carcinoma cells.

AIM: To investigate the effects of rosiglitazone, a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, on the expression of the phosphatase and tensin homologue deleted on chromosome 10 gene (PTEN) and cell growth in hepatocellular carcinoma cells, as well as the underlying mechanisms of these effects. METHODS: RT-PCR and Western blotting analyses were performed to detect transcription and the expression of PTEN in Hep3B cells treated with rosiglitazone. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to evaluate cell growth. Flow cytometry, DNA fragmentation analysis, caspase enzymatic assay, and Hoechst 33258 staining were used to determine cell apoptosis. Furthermore, small interfering RNA was used to suppress PTEN expression. RESULTS: Rosiglitazone increased the expression of PTEN in a dose- and time-dependent manner through the PPARgamma-dependent signal transduction pathway. PTEN upregulation was concomitant with a decreased level of Akt phosphorylation, subsequently resulting in cell growth inhibition and apoptosis in Hep3B cells. PTEN knockdown dramatically blocked these effects of rosiglitazone. Moreover, the exposure of cells to rosiglitazone activated caspases-9 and -3 during apoptotic proceeding. CONCLUSION: Thus, upregulation of PTEN is involved in the inhibition of cell growth and the induction of cell apoptosis by rosiglitazone, suggesting that rosiglitazone may be useful in liver cancer therapy via apoptosis.