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AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC50) and reversal index (IC50 in experimental group/IC50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.

Background. None of treatment options for Cholangiocarcinoma (CCA), including surgery, adjuvant radiotherapy and chemotherapy, and ultimately liver transplantation, have been shown to substantially improve the survival rate in patients with CCA. Valproic acid (VPA), a histone deacetylase inhibitor, has been shown to display potent antitumor effects. In this study, sodium valproate, the clinically available form of VPA, was tested for its ability to inhibit the growth of cholangiocarcinoma cells, bothin vitroandin vivo. Materials and Methods.Cholangiocarcinoma cells (TFK-1, QBC939, and CCLP1) of different origins were treated with sodium valproate to determine their effects on cell proliferation and differentiation, cell cycle regulation, apoptosis, and autophagy. Thein vivoeffects of sodium valproate on cholangiocarcinoma growth were assessed using a xenograft mouse model injected with TFK-1 cells.Results. Sodium valproate inhibited cholangiocarcinoma cell growth by inducing cell cycle arrest, cell differentiation, and apoptosis; sodium valproate effects were independent of autophagy. Tumor growth inhibition was also observedin vivousing TFK-1 xenografts.Conclusion. Thein vitroandin vivooutcomes provide preclinical rationale for clinical evaluation of sodium valproate, alone or in combination with other drugs, to improve patient outcome in cholangiocarcinoma.

AIM: To investigate the reciprocal modulation between microRNA (miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpG-binding domain protein (MBD)2. METHODS: MiR-373 expression was examined using the TaqMan miRNA assay. Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction, and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay. Mutation analysis was conducted using the QuikChange™ Site-Directed Mutagenesis kit. The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region (3’UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay. RESULTS: In hilar cholangiocarcinoma, miR-373 decreased and was closely associated with poor cell differentiation, advanced clinical stage, and shorter survival. The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373. MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373. Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island, and miR-373 negatively regulated MBD2 expression through targeting the 3’UTR. CONCLUSION: MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.

AIM: To identify methylation profile and novel tumor marker of extrahepatic cholangiocarcinoma (CCA) with high throughout microarray. METHODS: Differential methylation profile was compared between normal bile duct epithelial cell lines and CCA cell lines by methyl-DNA immunoprecipitation (MeDIP) microarray. Bisulfite-polymerase chain reaction (BSP) was performed to identify the methylated allels of target genes. Expression of target genes was investigated before and after the treatment with DNA demethylating agent. Expression of candidate genes was also evaluated by immunofluorescence in 30 specimens of CCA tissues and 9 normal bile duct tissues. RESULTS: Methylation profile of CCA was identified with MeDIP microarray in the respects of different gene functions and signaling pathways. Interestingly, 97 genes with hypermethylated CpG islands in the promoter region were homeobox genes. The top 5 hypermethylated homeobox genes validated by BSP were HOXA2 (94.29%), HOXA5 (95.38%), HOXA11 (91.67%), HOXB4 (90.56%) and HOXD13 (94.38%). Expression of these genes was reactivated with 5’-aza-2’-deoxycytidine. Significant expression differences were found between normal bile duct and extrahepatic CCA tissues (66.67%-100% vs 3.33%-10%). CONCLUSION: HOXA2, HOXA5, HOXA11, HOXB4 and HOXD13 may work as differential epigenetic biomarkers between malignant and benign biliary tissues.

Background Hepatocellular carcinoma (HCC) is the third most common cause of cancer related mortality worldwide. 9-Nitrocamptothecin (9NC) is a potent topoisomerase-I inhibitor with strong anticancer effect. To increase the solubility and stability, we synthesized a novel 9NC loaded liposomes (9NC-LP) via incorporating 9NC into liposomes. In the present study, we determined the effects of 9NC and 9NC-LP on in vitro and in vivo, and the underlying mechanisms. Methodology/Principal Findings We first analyzed the characteristics of 9NC-LP. Then we compared the effects of 9NC and 9NC-LP on the proliferation and apoptosis of HepG2, Bel-7402, Hep3B and L02 cells in vitro. We also investigated their anticancer properties in nude mice bearing HCC xenograft in vivo. 9NC-LP has a uniform size (around 190 nm) and zeta potential (∼−11 mV), and exhibited a steady sustained-release pattern profile in vitro. Both 9NC and 9NC-LP could cause cell cycle arrest and apoptosis in a dose-dependent and p53-dependent manner. However, this effect was not ubiquitous in all cell lines. Exposure to 9NC-LP led to increased expression of p53, p21, p27, Bax, caspase-3, caspase-8, caspase-9 and apoptosis-inducing factor, mitochondrion-associated 1 and decreased expression of Bcl-2, cyclin E, cyclin A, Cdk2 and cyclin D1. Furthermore, 9NC-LP exhibited a more potent antiproliferative effect and less side effects in vivo. Western blot analysis of the xenograft tumors in nude mice showed similar changes in protein expression in vivo. Conclusions/Significance In conclusion, 9NC and 9NC-LP can inhibit HCC growth via cell cycle arrest and induction of apoptosis. 9NC-LP has a more potent anti-tumor effect and fewer side effects in vivo, which means it is a promising reagent for cancer therapy via intravenous administration.

AIM: To investigate the effects of exogenously mutated p27kip1 (p27) on proliferation and apoptosis of human cholangiocarcinoma cell line, QBC939 in vivo. METHODS: Adenoviral vectors were used to transfect mutated p27 cDNA into human QBC939 cell line. Expression of p27 was detected by RT-PCR. Western blot. Cell growth, morphological change, cell cycle, apoptosis and cloning formation were determined by MTT assay and flow cytometry. RESULTS: The expression of p27 protein and mRNA was increased significantly in QBC939 cell line transfected with Ad-p27mt. The transfer of Ad-p27mt could significantly inhibit the growth of QBC939 cells, decrease the cloning formation rate and induce apoptosis. p27 over expression caused cell cycle arrest at G0/G1 phase 72 h after infection with Ad-p27mt. CONCLUSION: p27 may cause cell cycle arrest at G0/G1 phase and subsequently lead to apoptosis. Recombinant adenovirus expressing mutant p27 may be potentially useful in gene therapy for cholangiocarcinoma.

AIM To study the clinicopathological characteristics of unsuspected gallbladder carcinoma (UGC). METHODS We retrospectively studied 23 cases of UGC in Tongji Hospital, and compared their clinicopathological characteristics with 33 cases of preoperatively diagnosed gallbladder carcinoma (PDGC). RESULTS The proportion of UGC coexisting with cholecystolithiasis was significantly higher than that of PDGC (chi(2) = 13.53, P < 0.01). The infection rate of hepatitis B virus was 21.74% (5/23) in UGC and 30.30% (10/33) in PDGC. Nine (39.13%) of 23 patients with UGC and 8/33 (24.24) PDGC had contact with schistosome pestilent water. The rate of multiple pregnancies was 56.52% (13/23) in the patients with UGC and 42.42% (14/33) in PDGC. The primary location of the UGC was mostly in the neck and body of the gallbladder, and that of the PDGC was often in the body and bottom. The incidence of Nevin stage I and II UGC was significantly higher than that of PDGC (chi(2) = 4.44, P < 0.05 and chi(2) = 4.96, P < 0.05) while that of Nevin stage V UGC was significantly lower than that of PDGC (chi(2) = 7.59, P < 0.01). According to the grading of carcinoma, the incidence of well-differentiated UGC was significantly higher than that of PDGC (chi(2) = 4.16, P < 0.05), and that of poorly-differentiated UGC was significantly lower than that of PDGC (chi(2) = 4.48, P < 0.05). CONCLUSION There are different characteristics between UGC and PDGC, such as in primary location, malignant degree and incidence of coexistence with cholecystolithiasis. Cholecystolithiasis, hepatitis B, schistosome and multiple pregnancies were high risk factors for gallbladder carcinoma.

To observe the effect of octreotide on apoptosis rate of human pancreatic cancer cells PC-3 after transfected with somatostatin receptor type 2 (SST2) gene.SST2 plasmid was transfected into PC-3 cells by liposome. Result of transfection was detected by immunocytochemical staining and Western blotting. Apoptosis rates of PC-3 cells under different dosages of octreotide were measured by MTT assay and flow cytometry (FCM).Apoptosis rate caused by octreotide of transfected PC-3 cells was 7.56+/-1.06% at the dosage of 0.20 microg/mL, 9.25+/-1.73% at the dosage of 0.40 microg/mL and 14.18+/-2.71% at the dosage of 0.80 microg/mL. Apoptosis rate caused by octreotide of non-transfected PC-3 cells was 5.76+/-0.75% at the dosage of 0.20 microg/mL, 6.69+/-0.80% at the dosage of 0.40 microg/mL and 7.26+/-1.28% at the dosage of 0.80 microg/mL. Transfected PC-3 cells growth inhibition rate caused by octreotide was 9.36+/-1.34% at the dosage of 0.20 microg/mL, 12.03+/-1.44% at the dosage of 0.40 microg/mL and 20.23+/-4.21% at the dosage of 0.80 microg/mL. Non-transfected PC-3 cells growth inhibition rate caused by octreotide was 6.44+/-0.66% at the dosage of 0.20 microg/mL, 7.65+/-0.88% at the dosage of 0.40 microg/mL and 9.29+/-1.32% at the dosage of 0.80 microg/mL. We found that octreotide caused higher apoptosis rate and inhibition rate in transfected groups than in non-transfected groups (P0.05) at the tested dosages (0.20, 0.40 and 0.80 microg/mL).Deficiency of SST2 was probably the major reason why octreotide had little effect on PC-3 cells. Transfecting SST2 gene could strengthen the ability of octreotide of killing PC-3 cells. It provided an experimental evidence for using both octreotide and transfection with SST2 gene on clinical treatment of pancreatic cancer.