NIR-Light-Triggered Mild-Temperature Hyperthermia to Overcome the Cascade Cisplatin Resistance for Improved Resistant Tumor Therapy.

Currently, cisplatin resistance has been recognized as a multistep cascade process for its clinical chemotherapy failure. Hitherto, it remains challenging to develop a feasible and promising strategy to overcome the cascade drug resistance (CDR) issue for achieving fundamentally improved chemotherapeutic efficacy. Herein, a novel self-assembled nanoagent is proposed, which is constructed by Pt(IV) prodrug, cyanine dye (cypate), and gadolinium ion (Gd3+), for systematically conquering the cisplatin resistance by employing near-infrared (NIR) light activated mild-temperature hyperthermia in tumor targets. The proposed nanoagents exhibit high photostability, GSH/H+-responsive dissociation, preferable photothermal conversion, and enhanced cellular uptake performance. In particular, upon 785-nm NIR light irradiation, the generated mild temperature of ≈ 43 °C overtly improves the cell membrane permeability and drug uptake, accelerates the disruption of intracellular redox balance, and apparently enhances the formation of Pt-DNA adducts, thereby effectively overcoming the CDR issue and achieves highly improved therapeutic efficacy for cisplatin-resistant tumor ablation.

Methylation mediated Gadd45ß enhanced the chemosensitivity of hepatocellular carcinoma by inhibiting the stemness of liver cancer cells.

BACKGROUND: Defects of the growth arrest DNA damage-inducible gene 45ß (Gadd45ß) play an important role in the progression of tumor and confer resistance to chemotherapy. However, the role of Gadd45ß in the apoptosis of hepatocellular carcinoma is still not clear. Purpose of this study was to explore the effect of Gadd45ß on the apoptosis of liver cancer cells, and the possible mechanism was examined. RESULT: In this study, we first confirmed the decreased expression of Gadd45ß in human liver cancer tissues and human liver cancer cell lines, when compared to the peri-tumor liver tissue and normal liver cells. And, it was found that Gadd45ß could inhibit the stemness of liver cancer cells, enhancing the apoptosis of cancer cells induced by chemotherapy. Furthermore, the results showed that HCC tissues and cell lines showed a higher methylation status in Gadd45ß promoter than that in peri-tumor tissues and normal liver cells. Methylation was then reversed by pretreatment of SMMC-7721 and Hep-3B with 5-azacytidine which is the DNA methyltransferase inhibitor. And the 5-azacytidine decreased the stemness of SMMC-7721 and Hep-3B, enhanced the sensitivity of SMMC-7721 and Hep-3B to cisplatin. CONCLUSIONS: Methylation mediated Gadd45ß expression inhibited the stemness of liver cancer cells, promoting the chemotherapy-induced apoptosis. Thus Gadd45ß may be the potential target for enhancing the chemosensitivity of human hepatocellular carcinoma.

Underexpression of LKB1 tumor suppressor is associated with enhanced Wnt signaling and malignant characteristics of human intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is a rare and highly aggressive malignancy. In this study, we identified the presence of gene deletion and missense mutation leading to inactivation or underexpression of liver kinase B1 (LKB1) tumor suppressor and excluded the involvement of LKB1 gene hypermethylation in ICC tissues. Immunohistochemical analysis showed that LKB1 was underexpressed in a portion of 326 ICC tissues compared to their adjacent normal tissues. By statistical analysis underexpression of LKB1 in ICC tissues significantly correlated with poor survival and malignant disease characteristics in ICC patients. Moreover, we showed that knockdown of LKB1 significantly enhanced growth, migration, and invasion of three LKB1-competent ICC cell lines. Global transcriptional profiling analysis identified multiple malignancy-promoting genes, such as HIF-1α, CD24, Talin1, Vinculin, Wnt5, and signaling pathways including Hedgehog, Wnt/ß-catenin, and cell adhesion as novel targets of LKB1 underexpression in ICC cells. Furthermore, knockdown of LKB1 gene expression dramatically enhanced Wnt/ß-catenin signaling in ICC cells, while an inverse correlation between LKB1 and nuclear ß-catenin was observed in ICC tissues. Our findings suggest a novel mechanism for ICC carcinogenesis in which LKB1 underexpression enhances multiple signaling pathways including Wnt/ß-catenin to promote disease progression.

KAT5 silencing induces apoptosis of GBC-SD cells through p38MAPK-mediated upregulation of cleaved Casp9.

The poor overall prognosis of Gallbladder carcinoma (GBC) patients and the limited therapeutic regimens for these patients demonstrates the need for better therapeutic modalities, while the growing evidences have indicated that those genes contributed to epigenetic regulation may serve as therapeutic targets. The function of histone acetylation on growth and survival of GBC cells remains unknown. In present study, an RNAi screening of 16 genes involving histone acetyltransferases (HATs) was applied to GBC-SD cells and we found that KAT5 knockdown specifically inhibits the proliferation of GBC-SD cells by casp9-mediated apoptosis. Microarray data analysis showed that KAT5 RNAi may result in cleaved casp9 upregulation through p38MAPK activation in GBC-SD cells. The mRNA expression level of KAT5 was significantly upregulated in GBC tissues than in the adjacent normal tissues. In consistence with the mRNA level, the protein expression of KAT5 was markedly increased in tissues from patients with poor prognosis than those with good prognosis. These findings strongly indicated that KAT5 was implicated in GBC tumorigenesis and that its expression level was associated with the prognosis. Our work may also provide a potential therapeutic target for treatment of GBC patients.

An aqueous rechargeable battery based on zinc anode and Na(0.95)MnO2.

An aqueous rechargeable battery system is assembled by using metallic zinc and Na(0.95)MnO2 as the negative and positive electrodes, respectively. It is cheap and environmentally friendly, and its energy density is 78 Wh kg(-1). Its cycling performance is very good with only 8% capacity loss after 1000 cycles at 4 C between 1 and 2 V.

Inflammatory gene variants and the risk of biliary tract cancers and stones: a population-based study in China.

BACKGROUND: Genetic variants in inflammation-related genes have been associated with biliary stones and biliary tract cancers in previous studies. METHODS: To follow-up on these findings, we examined 35 single nucleotide polymorphism (SNPs) in 5 genes related to inflammation (IL8, NFKBIL, RNASEL, TNF, and VEGFA) in 456 participants with incident biliary tract cancer cases (262 gallbladder, 141 extrahepatic bile duct, 53 ampulla of Vater), 982 participants with biliary stones, and 860 healthy controls in a population-based case-control study in Shanghai, China. RESULTS: Suggestive associations were observed for SNPs in VEGFA with biliary stones, IL8 with gallbladder and ampulla of Vater cancers, and RNASEL with ampulla of Vater cancer (false discovery rate≤0.2). CONCLUSION: These findings provide additional support for the role of inflammation in biliary stones and biliary tract cancer risk and need further validation.

Early control of short hepatic portal veins in isolated or combined hepatic caudate lobectomy.

BACKGROUND: Caudate lobectomy has long been considered technically difficult. This study aimed to elaborate the significance of early control of short hepatic portal veins (SHPVs) in isolated hepatic caudate lobectomy or in hepatic caudate lobectomy combined with major partial hepatectomy, and to describe the anatomical characteristics of SHPVs. METHODS: The data of 117 patients who underwent either isolated or combined caudate lobectomy by the same team of surgeons from 2005 to 2009 were retrospectively analyzed. From 2005 to 2007 (group A, n=55), we carried out early control of short hepatic veins (SHVs) only; from 2008 to 2009 (group B, n=62), we carried out early control of both SHVs and SHPVs. The two groups were compared to evaluate which surgical procedure was better. A detailed anatomical study was then carried out on the last 25 consecutive patients in group B to study the number and distribution of SHPVs during surgery. RESULTS: Patients in group B had less intra-operative blood loss, less impairment of liver function, shorter postoperative hospital stay, fewer postoperative complications and required less blood transfusion (P<0.05). The number of SHPVs in the 25 patients was 183, with 7.3+/-2.7 per patient. The diameters of SHPVs were 1 to 4 mm. On average, 3.4 SHPVs/patient came from the left portal vein, 2.2 from the bifurcation, 1.4 from the right portal vein, and 0.3 from the main portal vein. On average, 3.3 SHPVs/patient supplied segment I of the liver, 0.4 for segment II, 2.1 for segment IV, 1.4 for segment V and 0.1 for segment VI. CONCLUSION: Early control of SHPVs in isolated or combined hepatic caudate lobectomy may be a useful method to decrease surgical risk and improve postoperative recovery.

Role of radical resection in patients with gallbladder carcinoma and jaundice.

BACKGROUND: Gallbladder carcinoma (GBC) is a commonly-seen malignancy of the biliary tract characterized by difficult early diagnosis, rapid growth, early metastasis, and poor prognosis. Nearly half of GBC patients also have jaundice, which is a mark of the advanced stage of GBC. The role of radical resection in patients of gallbladder carcinoma with jaundice is still a matter of uncertainty, which we attempted to clarify in this study. METHODS: Totally, 251 GBC patients who received treatment at the Eastern Hepatobiliary Surgery Hospital (EHBH) from December 2002 to January 2010 were recruited into this study. We divided them into group A (jaundice group, n=117) and group B (non-jaundice group, n=134). Clinical records and follow-up data were collected and retrospectively analyzed in both groups. RESULTS: Compared with group A, patients in group B had a longer median survival time ((6.0±0.5) months vs. (15.0±2.6) months, P<0.01). Even in patients with stage III or stage IV GBC, the median survival time in patients without jaundice (n=111), was still longer than that in patients with jaundice (n=116) (P<0.01). The radical resection rate was lower in group A patients than in group B patients with stage III or stage IV GBC; 31.9% vs. 63.1%. However, the median survival time of patients undergoing radical resection did not show a statistical difference between jaundice patients and non-jaundice patients; (12.0±4.3) months vs. (18.0±3.0) months (P>0.05). CONCLUSIONS: GBC with jaundice usually implies advanced stage disease and a poor prognosis for the patients. However, our findings indicate that as long as the patient's condition allows, radical resection is still feasible for GBC patients with jaundice, and may achieve a prognosis close to those GBC patients without jaundice.

Medical history and the risk of biliary tract cancers in Shanghai, China: implications for a role of inflammation.

Several lines of evidence suggest that inflammation may play a role in the etiology of biliary tract cancers. To examine further the role of inflammation, we evaluated the associations between self-reported inflammatory-related medical conditions and the risk of biliary tract cancers in a population-based case-control study in Shanghai, China. Our analysis included 368 gallbladder cancer cases, 191 bile duct cancer cases, 68 ampulla of Vater cancer cases, and 959 healthy subjects. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for biliary tract cancers in relation to six inflammation-related conditions. Gallbladder cancer was significantly associated with cholecystitis occurring at least 5 years prior to interview (OR = 1.7, 95% CI 1.1-2.9). Even though biliary stones did not significantly modify the associations between cholecystitis and gallbladder cancer, 90% of the gallbladder cancer cases with cholecystitis also had biliary stones, indicating that stones likely play an important role in the link between cholecystitis and gallbladder cancer. Among subjects who smoked and drank alcohol, a history of gastric (OR = 4.3, 95% CI 1.2-15.0) or duodenal ulcers (OR = 3.7, 1.2-12.0) was associated with an excess risk of gallbladder cancer. Although the mechanisms are unclear, our results further support the role for inflammation in the etiology of biliary tract cancers.

Sorafenib extends the survival time of patients with multiple recurrences of hepatocellular carcinoma after liver transplantation.

AIM: to determine the efficacy and toxicities of sorafenib in the treatment of patients with multiple recurrences of hepatocellular carcinoma (HCC) after liver transplantation in a Chinese population. METHODS: twenty patients with multiple recurrences of HCC after liver transplantation were retrospectively studied. They received either transarterial chemoembolization (TACE) or TACE combined with sorafenib. RESULTS: the median survival times (MST) after multiple recurrences was 14 months (TACE+sorafenib group) and 6 months (TACE only group). The difference was significant in MST between the two groups (P=0.005). The TACE + sorafenib group had more stable disease (SD) patients than the TACE group. The most frequent adverse events of sorafenib were hand-foot skin reaction and diarrhea. In the univariate analysis, preoperative bilirubin and CHILD grade are found to be significantly associated with tumor-free survival time, the survival time after multiple recurrences and overall survival time. TACE+sorafenib group showed a better outcome than single TACE treatment group. In the multivariate COX regression modeling, the preoperative high CHILD grade was found to be a risk factor of tumor-free survival time. In addition, the preoperative high bilirubin grade was also found to be a risk factor of survival time after recurrence and overall survival time. Furthermore, survival time after recurrence and overall survival time were also associated with therapeutic schedule, which was indicated by the GROUP. CONCLUSION: Treatment with TACE and sorafenib is worthy of further study and may have more extensive application prospects.

Androgen receptor CAG repeat length and risk of biliary tract cancer and stones.

Biliary tract cancers, encompassing cancers of the gallbladder, extrahepatic bile ducts, and ampulla of Vater, are rare but highly fatal. Gallstones represent the major risk factor for biliary tract cancer, and share with gallbladder cancer a female predominance and an association with reproductive factors and obesity. Although estrogens have been implicated in earlier studies of gallbladder cancer, there are no data on the role of androgens. Because intracellular androgen activity is mediated through the androgen receptor (AR), we examined associations between AR CAG repeat length [(CAG)(n)] and the risk of biliary tract cancers and stones in a population-based study of 331 incident cancer cases, 837 gallstone cases, and 750 controls from Shanghai, China, where the incidence rates for biliary tract cancer are rising sharply. Men with (CAG)(n) >24 had a significant 2-fold risk of gallbladder cancer [odds ratio (OR), 2.00; 95% confidence interval (CI), 1.07-3.73], relative to those with (CAG)(n) < or = 22. In contrast, women with (CAG)(n) >24 had reduced gallbladder cancer risk (OR, 0.69; 95% CI, 0.43-1.09) relative to those with (CAG)(n) < or = 22; P interaction sex = 0.01, which was most pronounced for women ages 68 to 74 (OR, 0.48; 95% CI, 0.25-0.93; P interaction age = 0.02). No associations were found for bile duct cancer or gallstones. Reasons for the heterogeneity of genetic effects by gender and age are unclear but may reflect an interplay between AR and the levels of androgen as well as estrogen in men and older women. Further studies are needed to confirm these findings and clarify the mechanisms involved.

Polymorphisms of estrogen receptors and risk of biliary tract cancers and gallstones: a population-based study in Shanghai, China.

Biliary tract cancer encompasses tumors of the gallbladder, bile duct and ampulla of Vater. Gallbladder cancer is more common in women, whereas bile duct cancer is more common in men, suggesting that sex hormones may play a role in the etiology of these cancers. The intracellular action of estrogens is regulated by the estrogen receptor (ESR); thus, we examined the role of common genetic variants in ESR genes on the risk of biliary tract cancers and stones in a population-based case-control study in Shanghai, China (411 cancer cases, 895 stone cases and 786 controls). We genotyped six single-nucleotide polymorphisms (SNPs), four in ESR1 (rs2234693, rs3841686, rs2228480 and rs1801132) and two in ESR2 (rs1256049 and rs4986938). In all participants, the ESR1 rs1801132 (P325P) G allele was associated with excess risks of bile duct [odds ratio (OR) = 1.7, 95% confidence interval (CI) 1.1-2.8] and ampulla of Vater cancers (OR = 2.1, 95% CI 0.9-4.9) compared with the CC genotype. The association with bile duct cancer was apparent among men (OR = 2.8, 95% CI 1.4-5.7) but not among women (P-heterogeneity = 0.01). Also, the ESR2 rs4986938 (38 bp 3' of STP) GG genotype was associated with a higher risk of bile duct cancer (OR = 3.3, 95% CI 1.3-8.7) compared with the AA genotype, although this estimate was based on a small number of subjects. None of the other SNPs examined was associated with biliary tract cancers or stones. False discovery rate-adjusted P-values were not significant (P > 0.1). No association was found for ESR1 haplotype based on four SNPs. These preliminary results suggest that variants in ESR genes could play a role in the etiology of biliary tract cancers, especially bile duct cancer in men.

Preoperative portal vein embolization for hilar cholangiocarcinoma--a comparative study.

BACKGROUND/AIMS: Preoperative portal vein embolization (PVE) allows potentially curative hepatic resection to be carried out in patients with hepatobiliary malignancies who are otherwise not candidates for resection because of the small size of the future liver remnant (FLR). However, there have only been a few reports on PVE before hepatectomy for hilar cholangiocarcinoma due to the small number of patients who can be treated with radical surgery. METHODOLOGY: Between January 2007 and March 2009, 49 consecutive patients with hilar cholangiocarcinoma who were planned to have hemi-hepatectomy/extended hemi-hepatectomy plus caudate lobe resection in our tertiary referral center were studied. The change in size of the FLR and the operative outcomes were compared between patients with or without PVE. RESULTS: All patients had liver dysfunction as a result of biliary obstruction due to hilar cholangiocarcinoma although they had all received percutaneous transhepatic biliary drainage. PVE was used in 16 patients with an estimated FLR of <50%, while no PVE was carried out in 33 patients with an estimated FLR of >50%. Complications after PVE occurred in 3 patients (18.8%), which included bile leakage (n=1) and coil displacement (n=2). No complication precluded liver resection. The FLR to total liver volume (TLV) ratio at presentation was significantly smaller in patients who underwent PVE than those who did not undergo PVE (40.3 +/- 7.4% vs. 56.6 +/- 5.0%; p < 0.001). After PVE, the FLR to TLV ratio increased significantly (40.3 +/- 7.4% vs. 43.1 +/- 7.0%; p < 0.001) at a mean time of 14.2 +/- 3.5 days. The mean +/- S.D. increase in FLR was 4.6 +/- 3.0 cm3/day. At surgery, the FLR volume was still significantly smaller in the PVE group than the non-PVE (802 +/- 216 cm3 vs. 979 +/- 202 cm3; p = 0.007). In the PVE group, insufficient hypertrophy of the FRL prevented one patient from having surgery, while local tumor progression and peritoneal dissemination precluded hepatectomy in 2 more patients. Finally, 13 patients (81.3%) underwent radical surgery. The PVE group had similar complication and mortality rates compared with the non-PVE group (complication rate, 69.2% vs. 63.6%; mortality rate, 0.0% vs. 9.1%). The 1- and 2-year overall survivals for the PVE group (with intent-to-treat analysis), PVE group (radical surgery only) and the non-PVE group were 57.3% and 43.0%; 71.3% and 53.5%; 70.4% and 54.4%, respectively. There was no significant difference in the survival outcomes. CONCLUSIONS: The results suggested that PVE is a safe and efficacious procedure in inducing adequate hypertrophy of the FLR before major hepatic resection for hilar cholangiocarcinoma with obstructive jaundice which had been relieved by percutaneous transhepatic biliary drainage.

A special growth manner of intrahepatic biliary cystadenoma.

We report a case of a 56-year-old woman with intrahepatic biliary cystadenoma (IBC) accompanying a tumor embolus in the extrahepatic bile duct, who was admitted to our department on October 13, 2008. Imaging showed an asymmetry dilation of the biliary tree, different bile signals in the biliary tree, a multiloculated lesion and an extrahepatic bile duct lesion with internal septation. A regular left hemihepatectomy en bloc was performed with resection of the entire tumor, during which a tumor embolus protruding into the extrahepatic bile duct and originating from biliary duct of segment 4 was revealed. Microscopically, the multiloculated tumor was confirmed to be a biliary cystadenoma with an epithelial lining composed of biliary-type cuboidal cells and surrounded by an ovarian-like stroma. An aggressive en bloc resection was recommended for the multiloculated lesion. Imaging workup, clinicians and surgeons need to be aware of this different presentation.

Up-regulation of hTERT expression by low-dose cisplatin contributes to chemotherapy resistance in human hepatocellular cancer cells.

The telomerase is specifically activated in most malignant tumors but is usually inactive in normal somatic cells. It has been reported that telomerase has an anti-apoptotic role and up-regulation of telomerase helps cancer cells to be resistant to chemotherapeutic agent-induced cell death. The effect of cisplatin on telomerase activity is complex, and the exact mechanism remains largely unknown. In this study, we found that cisplatin activated telomerase activity and human telomerase reverse transcriptase (hTERT) expression in SMMC7721 human hepatocellular carcinoma cell line. Low-dose cisplatin up-regulated hTERT and NF-kappaB p65 expression and increased telomerase and NF-kappaB activity. Inhibition of NF-kappaB attenuated the hTERT expression and telomerase activity exposed to cisplatin, suggesting that NF-kappaB is responsible for the cisplatin-induced activation of the hTERT. Furthermore, preincubation of low-dose cisplatin which induced high expression of hTERT help hepatocellular carcinoma SMMC7721 cells survive under the high concentration of anti-cancer drugs. Inhibition of hTERT increased sensitivity of SMMC7721 cells to chemotherapy. Taken together, these results suggested that up-regulation of hTERT expression by low-dose cisplatin is NF-kappaB-dependent and contributes to chemotherapy resistance in human hepatocellular cancer cells.

Variants in hormone-related genes and the risk of biliary tract cancers and stones: a population-based study in China.

Biliary tract cancers, encompassing gallbladder, extrahepatic bile duct and ampulla of Vater cancers, are uncommon but often fatal malignancies. Hormone-related factors, including parity, oral contraceptive use, obesity, and gallstones, have been implicated in the etiology of these cancers. To further clarify the role of hormones in biliary tract cancers and biliary stones, we genotyped 18 single-nucleotide polymorphisms (SNPs) in nine genes involved in steroid hormone biosynthesis, metabolism and transport in a population-based case-control study in Shanghai, China. This study included subjects who completed an interview and provided blood, which totaled 411 biliary tract cancer and 893 biliary stone patients and 786 healthy Shanghai residents. The CYP1A1 IVS1 + 606 (rs2606345) T allele was associated with gallbladder [odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.3-3.0] and bile duct cancers (OR = 1.8, 95% CI = 1.1-3.1), whereas the CYP1A1 Ex7 + 131 (rs1048943) G allele was associated with ampulla of Vater cancer (OR = 2.9, 95% CI = 1.5-5.4). After taking into account multiple comparisons for SNPs within each gene, CYP1A1 was significantly associated with gallbladder (P = 0.004) and ampulla of Vater cancers (P = 0.01), but borderline with bile duct cancer (P = 0.06). The effect of CYP1A1 IVS1 + 606 on gallbladder cancer was more pronounced among non-obese (body mass index < 23) (OR = 3.3, 95% CI = 1.8-6.1; P interaction = 0.001). Among women taking oral contraceptives, the effect of SHBG Ex8 + 6 (rs6259) on gallbladder cancer (OR = 6.7, 95% CI = 2.2-20.5; P interaction = 0.001) and stones (OR = 2.3, 95% CI = 1.1-4.9; P-interaction = 0.05) was statistically significant. Our findings suggest that common variants in hormone-related genes contribute to the risk of biliary tract cancers and stones, possibly by modulating hormone metabolism.

Increased p38-MAPK is responsible for chemotherapy resistance in human gastric cancer cells.

BACKGROUND: Chemoresistance is one of the main obstacles to successful cancer therapy and is frequently associated with Multidrug resistance (MDR). Many different mechanisms have been suggested to explain the development of an MDR phenotype in cancer cells. One of the most studied mechanisms is the overexpression of P-glycoprotein (P-gp), which is a product of the MDR1 gene. Tumor cells often acquire the drug-resistance phenotype due to upregulation of the MDR1 gene. Overexpression of MDR1 gene has often been reported in primary gastric adenocarcinoma. METHODS: This study investigated the role of p38-MAPK signal pathway in vincristine-resistant SGC7901/VCR cells. P-gp and MDR1 RNA were detected by Western blot analysis and RT-PCR amplification. Mitgen-activated protein kinases and function of P-gp were demonstrated by Western blot and FACS Aria cytometer analysis. Ap-1 activity and cell apoptosis were detected by Dual-Luciferase Reporter Assay and annexin V-PI dual staining. RESULTS: The vincristine-resistant SGC7901/VCR cells with increased expression of the multidrug-resistance 1 (MDR1) gene were resistant to P-gp-related drug and P-gp-unrelated drugs. Constitutive increases of phosphorylated p38-MAPK and AP-1 activities were also found in the drug-resistant cells. Inhibition of p38-MAPK by SB202190 reduced activator protein-1 (AP-1) activity and MDR1 expression levels and increased the sensitivity of SGC7901/VCR cells to chemotherapy. CONCLUSION: Activation of the p38-MAPK pathway might be responsible for the modulation of P-glycoprotein-mediated and P-glycoprotein-unmediated multidrug resistance in the SGC7901/VCR cell line.

siRNA-mediated inhibition of hTERT enhances chemosensitivity of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. However, there is no effective treatment for HCC. It has been shown that sustained activation of telomerase is essential for the growth and progression of HCC, suggesting that telomerase is a rational target for HCC therapy. Here, we investigated the effects of siRNA-mediated knockdown of hTERT, the catalytic and rate-limiting subunit of telomerase, on the sensitivity of HCC cells to cisplatin. While silencing of hTERT and the resultant inhibition of telomerase activity by infection with the recombinant adenovirus expressing a hTERT siRNA (Ad-si/hTERT) alone did not affect the proliferation and viability of SMMC7721 and HepG2 HCC cells within five days, co-administration of Ad-si/hTERT, but not the empty adenovirus vector, with cisplatin caused much greater extent of apoptosis in vitro under the same conditions and induced significantly more robust inhibition of SMMC7721 and HepG2 tumors growth in a mouse tumor xenograft model than cisplatin monotherapy. Our results demonstrated the synergistic effect between hTERT siRNA and cisplatin in the suppression of HCC progression and indicated that the combination of hTERT-specific siRNA and cisplatin could be an effective therapy for HCC.

Methylation-related silencing of p14ARF gene correlates with telomerase activity and mRNA expression of human telomerase reverse transcriptase in hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: The p14(ARF) gene encodes a critical negative regulator of cell cycle progression. And upregulation of telomerase activity has been considered a critical step to tumors. We investigated promoter methylation of p14(ARF) and expression as well as their effect on hTERT expression and telomerase activity in HCC. METHODS: We studied p14(ARF) methylation and mRNA in 30 hepatocellular carcinomas and corresponding non-tumor liver tissues using methylation-specific PCR. Reverse transcription-PCR was performed for expression of p14(ARF) and hTERT. Telomerase activity was performed by TRAP assay. RESULTS: p14(ARF) hypermethylation was detected in 16 (53.3%) of HCC and 10 (33.3%) of non-tumor tissues, and 12 of 16 with methylation were tumor tissues around large size (> or =5 cm). p14(ARF) mRNA was observed in 25%, 80.0%, or 50.0% of tumors with hypermethylated, partially methylated or unmethylated p14(ARF) promoter, respectively. Among the 16 tumors with p14(ARF) hypermethylation, all 12 tumors lacking p14(ARF) mRNA were positive for hTERT expression, while only one of 4 tumors expressing p14(ARF) mRNA was positive for hTERT expression. CONCLUSIONS: p14(ARF) hypermethylation may contribute to silencing of p14(ARF) mRNA expression in HCC. Telomerase activity is association with inactivation of the p14(ARF)-p53 pathway induced by methylation in HCC.

Polymorphism of genes related to insulin sensitivity and the risk of biliary tract cancer and biliary stone: a population-based case-control study in Shanghai, China.

Biliary tract cancer, encompassing tumors of the gallbladder, extrahepatic bile ducts and ampulla of Vater, is a rare but highly fatal malignancy. Obesity and gallstones, both related to insulin resistance, are linked to an elevated risk of biliary cancer. The peroxisome proliferator-activated receptors (PPARs) and the retinoid X receptors (RXRs), expressed in adipose tissue, play a key role in the regulation of obesity-related insulin sensitivity, thus genetic variants of these two receptor genes may be related to biliary cancer and stones. We examined the associations of seven single-nucleotide polymorphisms in the PPAR-gamma, PPAR-delta, RXR-alpha, RXR-beta and INS genes with biliary cancer and stones in a population-based case-control study in Shanghai, China. We included 237 gallbladder, 127 extrahepatic bile duct and 47 ampulla of Vater cancer cases, 895 stone cases and 786 population controls. Relative to individuals with the RXR-beta C51T (rs2076310) CC genotype, those having the TT genotype had a 1.6-fold risk for bile duct cancer [odds ratio (OR) = 1.67; 95% confidence interval (CI) = 0.99-2.84], with a more pronounced association among men (OR = 2.30; 95% CI = 1.14-4.65; P interaction = 0.07). This marker was also associated with a higher risk of gallstones among subjects with a higher body mass index (BMI) (>or=23 kg/m(2)) (OR = 1.80; 95% CI = 1.09-2.94), although the interaction with BMI was not statistically significant (P interaction = 0.28). No association was found between other variants and biliary cancers and stones. Results from this population-based study suggest that certain genetic variants involved in the regulation of obesity-related insulin sensitivity may increase susceptibility to bile duct cancer and gallstones.