Modified technique of Hepatojejunostomy for biliary tract reconstruction after resection of tumors affecting the perihilar region: a case series.

BACKGROUNDS: Radical resection is the most effective treatment for perihilar tumors. Biliary tract reconstruction after resection is one of the key steps in this surgery. Mucosa-to-mucosa cholangiojejunostomy is traditionally performed, in which the bile ducts at the resection margin are separately anastomosed to the jejunum. However, this approach is associated with long operative time and high risk of postoperative complications. The present study presents a modified technique of hepatojejunostomy and its outcomes. METHODS: The data of patients who underwent hepatojejunostomy using the modified technique at the Department of Hepatobiliary Surgery, Daping Hospital, Army Medical University, Chongqing, China, from January 2016 to December 2021, were retrospectively analyzed. RESULTS: A total of 13 patients with perihilar tumors underwent R0 resection and bilioenteric reconstruction using the modified hepatojejunostomy technique during the study period. During the operation, the alignment of the bile duct stumps was improved, the posterior wall of the anastomosis was reinforced, internal stents were placed in the smaller bile ducts, external stents were placed in the larger bile ducts, and hepatojejunostomy was performed using 4 - 0 prolene. No serious postoperative complications, such as death or bile leakage, occurred during the hospitalization. Furthermore, there were no cases of biliary stricture or cholangitis after the six-month follow-up period. CONCLUSION: The modified hepatojejunostomy technique is a safe and effective technique of biliary reconstruction after the resection of perihilar tumors. This can be easily performed for difficult cases with multiple bile ducts that require reconstruction after resection.

Upregulation of miR-124-3p by Liver X Receptor Inhibits the Growth of Hepatocellular Carcinoma Cells Via Suppressing Cyclin D1 and CDK6.

MiR-124-3p has been identified as a novel tumor suppressor and a potential therapeutic target in hepatocellular carcinoma (HCC) through regulating its target genes. However, the upstream regulatory mechanisms of mir-124-3p in HCC has not been fully understood. The transcription factor liver X receptor (LXR) plays a critical role in suppressing the proliferation of HCC cells, but it is unclear whether LXR is involved in the regulation of mir-124-3p. In the present study, we demonstrated that the expression of mir-124-3p was positively correlated with that of LXR in HCC, and the cell growth of HCC was significantly inhibited by LXR agonists. Moreover, activation of LXR with the agonists up-regulated the expression of mir-124-3p, and in turn down-regulated cyclin D1 and cyclin-dependent kinase 6 (CDK6) expression, which are the target genes of mir-124-3p. Mechanistically, miR-124-3p mediates LXR induced inhibition of HCC cell growth and down-regulation of cyclin D1 and CDK6 expression. In vivo experiments also confirmed that LXR induced miR-124-3p expression inhibited the growth of HCC xenograft tumors, as well as cyclin D1 and CDK6 expression. Our findings revealed that miR-124-3p is a novel target gene of LXR, and regulation of the miR-124-3p-cyclin D1/CDK6 pathway by LXR plays a crucial role in the proliferation of HCC cells. LXR-miR-124-3p-cyclin D1/CDK6 pathway may be a novel potential therapeutic target for HCC treatment.

Oncogenic Mutations in Armadillo Repeats 5 and 6 of ß-Catenin Reduce Binding to APC, Increasing Signaling and Transcription of Target Genes.

BACKGROUND & AIMS: The ß-catenin signaling pathway is one of the most commonly deregulated pathways in cancer cells. Amino acid substitutions within armadillo repeats 5 and 6 (K335, W383, and N387) of ß-catenin are found in several tumor types, including liver tumors. We investigated the mechanisms by which these substitutions increase signaling and the effects on liver carcinogenesis in mice. METHODS: Plasmids encoding tagged full-length ß-catenin (CTNNB1) or ß-catenin with the K335I or N387K substitutions, along with MET, were injected into tails of FVB/N mice. Tumor growth was monitored, and livers were collected and analyzed by histology, immunohistochemistry, and quantitative reverse-transcription polymerase chain reaction. Tagged full-length and mutant forms of ß-catenin were expressed in HEK293, HCT116, and SNU449 cells, which were analyzed by immunoblots and immunoprecipitation. A panel of ß-catenin variants and cell lines with knock-in mutations were analyzed for differences in N-terminal phosphorylation, half-life, and association with other proteins in the signaling pathway. RESULTS: Mice injected with plasmids encoding K335I or N387K ß-catenin and MET developed larger, more advanced tumors than mice injected with plasmids encoding WT ß-catenin and MET. K335I and N387K ß-catenin bound APC with lower affinity than WT ß-catenin but still interacted with scaffold protein AXIN1 and in the nucleus with TCF7L2. This interaction resulted in increased transcription of genes regulated by ß-catenin. Studies of protein structures supported the observed changes in relative binding affinities. CONCLUSION: Expression of ß-catenin with mutations in armadillo repeats 5 and 6, along with MET, promotes formation of liver tumors in mice. In contrast to N-terminal mutations in ß-catenin that directly impair its phosphorylation by GSK3 or binding to BTRC, the K335I or N387K substitutions increase signaling via reduced binding to APC. However, these mutant forms of ß-catenin still interact with the TCF family of transcription factors in the nucleus. These findings show how these amino acid substitutions increase ß-catenin signaling in cancer cells.

Tmub1 negatively regulates liver regeneration via inhibiting STAT3 phosphorylation.

Tmub1 (transmembrane and ubiquitin-like domain-containing 1) plays negative roles in rat hepatocyte proliferation, but its underlying molecular mechanisms in liver regeneration regulation have yet to be revealed. Here, we show that in vivo transfection of Tmub1 overexpression vectors impaired mouse liver regeneration after partial hepatectomy (PHx). Loss- and gain-of-function analyses in human hepatocyte Lo2 cells indicated that Tmub1 inhibits the phosphorylation of STAT3 and the activation of STAT3 signaling. Furthermore, the inhibitory effect of Tmub1 overexpression on hepatocyte proliferation can be reversed by the STAT3 activator OSM, while the promotive effect of Tmub1 knockdown can be abolished by the STAT3 inhibitor stattic. Coimmunoprecipitation assays revealed interaction between Tmub1 and STAT3. Finally, we present data from chromatin immunoprecipitation and luciferase reporter gene assays and report that STAT3 binds to and activates the promoter of Tmub1, suggesting a putative negative feedback loop between Tmub1 and STAT3 signaling. Taken together, the results of our study suggest that Tmub1 is an important negative regulator of hepatocyte proliferation in liver regeneration through STAT3 signaling. These findings provide a potential strategy for the management of liver regeneration.

TMUB1 Inhibits BRL-3A Hepatocyte Proliferation by Interfering with the Binding of CAML to Cyclophilin B through its TM1 Hydrophobic Domain.

Transmembrane and ubiquitin-like domain-containing 1 (Tmub1) encodes a protein (TMUB1) containing an ubiquitin-like domain and plays a negative regulatory role during hepatocyte proliferation, but its mechanism in this process is still unknown. Here, TMUB1 interfered with the binding of calcium-modulating cyclophilin ligand (CAML) to cyclophilin B, which may represent a key role in the negative regulatory process of TMUB1 in hepatocyte proliferation. Co-immunoprecipitation assays in rat BRL-3A cells confirmed the interaction between TMUB1 and CAML; significant regulation of the influx of Ca2+ ([Ca2+]i) and hepatocyte proliferation occurred following TMUB1 overexpression or knockout. Deletion of the TM1 hydrophobic domain of TMUB1 completely abolished this interaction and led to loss of TMUB1's regulatory effects on cytological behavior. Furthermore, overexpression of TMUB1 completely abolished the interaction between CAML and its downstream protein cyclophilin B, which can act upstream of calcineurin by increasing [Ca2+]i during cell proliferation. Taken together, our results indicate that TMUB1 regulates BRL-3A hepatocyte proliferation by interacting with CAML and further interferes with the binding of CAML to cyclophilin B to decrease cellular [Ca2+]i.

MiR-27a/b Regulates Liver Regeneration by Posttranscriptional Modification of Tmub1.

BACKGROUND: Transmembrane and ubiquitin-like domain-containing 1 protein (Tmub1) negatively regulates liver regeneration. However, whether this regulation involves posttranscriptional modification of Tmub1 expression is unknown. AIM: The aim of the study was to investigate whether microRNA (miR)-27a/b regulates posttranscriptional modification of Tmub1 and cell proliferation during liver regeneration. METHODS: Tmub1 mRNA 3'-untranslated region (UTR) sequences were analyzed using online software. A luciferase assay was used to verify the relationship between miR-27a/b and the 3'-UTR of Tmub1. Rat partial hepatectomy models were used to investigate miR-27a/b and Tmub1 levels after partial hepatectomy. MiR-27a/b expression was down- and up-regulated with mimics and inhibitors, respectively, to observe the effects of miR-27a/b on Tmub1 expression. Quantitative RT-PCR and Western blot analyses were used to measure miR-27a/b and Tmub1 expression. Hepatocyte proliferation was measured using the CCK8 method for BRL-3A liver cells and proliferating cell nuclear antigen and histone H3 phosphorylation in the regenerating liver. RESULTS: A potential binding site of miR-27a/b was found in the 3'-UTR sequence of Tmub1. Our luciferase assay confirmed that the Tmub1 mRNA 3'-UTR was the target of miR-27a/b. We observed a temporal correlation between miR-27a/b and Tmub1 expression during liver regeneration. MiR-27a/b down-regulated Tmub1 expression both in vivo and in vitro. MiR-27a/b regulated hepatocyte proliferation during liver regeneration. CONCLUSION: MiR-27a/b regulates hepatocyte proliferation by controlling posttranscriptional modification of Tmub1 during liver regeneration.

Proliferation­inhibiting pathways in liver regeneration (Review).

Liver regeneration, an orchestrated process, is the primary compensatory mechanism following liver injury caused by various factors. The process of liver regeneration consists of three stages: Initiation, proliferation and termination. Proliferation­promoting factors, which stimulate the recovery of mitosis in quiescent hepatocytes, are essential in the initiation and proliferation steps of liver regeneration. Proliferation­promoting factors act as the 'motor' of liver regeneration, whereas proliferation inhibitors arrest cell proliferation when the remnant liver reaches a suitable size. Certain proliferation inhibitors are also expressed and activated in the first two steps of liver regeneration. Anti­proliferation factors, acting as a 'brake', control the speed of proliferation and determine the terminal point of liver regeneration. Furthermore, anti­proliferation factors function as a 'steering­wheel', ensuring that the regeneration process proceeds in the right direction by preventing proliferation in the wrong direction, as occurs in oncogenesis. Therefore, proliferation inhibitors to ensure safe and stable liver regeneration are as important as proliferation­promoting factors. Cytokines, including transforming growth factor­ß and interleukin­1, and tumor suppressor genes, including p53 and p21, are important members of the proliferation inhibitor family in liver regeneration. Certain anti­proliferation factors are involved in the process of gene expression and protein modification. The suppression of liver regeneration led by metabolism, hormone activity and pathological performance have been reviewed previously. However, less is known regarding the proliferation inhibitors of liver regeneration and further investigations are required. Detailed information regarding the majority of known anti­proliferation signaling pathways also remains fragmented. The present review aimed to understand the signalling pathways that inhbit proliferation in the process of liver regeneration.

MiR-377 inhibits the proliferation of pancreatic cancer by targeting Pim-3.

MicroRNAs (miRNAs) play important roles in the regulation of various tumor biological processes including proliferation and apoptosis. MiR-377 has been implicated in many types of cancer, whereas its expressional feature and potential biological function in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, we scanned the global miRNA expression profiles in PDAC from The Cancer Genome Atlas (TCGA) and found miR-377 was down-regulated significantly in PDAC. Then, its expression was measured in both pancreatic cancer tissues and cells; the data showed that miR-377 was de-regulated and inversely correlated with pathologic parameters of tumor growth or metastasis. We generated PDAC cell lines with stable overexpression or inhibition of miR-377, and our results indicated that miR-377 up-regulation significantly promoted cell viability, proliferation, and migration in PDAC cells, and also induced cell apoptosis and cell cycle arrest simultaneously. Binding-site predictions by bioinformatics showed that Pim-3 might be a potential target of miR-377. Luciferase reporter assay ulteriorly identified that miR-377 suppressed Pim-3 expression by binding the 3'-UTR. In tumor tissues, we also showed that the Pim-3 expression was inversely correlated with that of miR-377. Furthermore, stable ectopic miR-377 expression in pancreatic cancer cell lines suppressed Pim-3 expression, leading to the attenuation of Bad phosphorylation level at its Ser112 and promoting cell apoptosis. Overall, these results reveal that miR-377 may have tumor growth suppression function by down-regulating Pim-3 kinase expression to inhibit both pancreatic tumor growth and migration, and induce cell apoptosis. Hence, miR-377 may be a potential diagnostic marker and therapeutic target.

Deltex1 Polymorphisms Are Associated with Hepatitis B Vaccination Non-Response in Southwest China.

BACKGROUND: Hepatitis B vaccination is the most important tool available for preventing hepatitis B virus (HBV) infection and reducing the prevalence of infection. However, epidemiological studies have demonstrated that morethan 5% of patients exhibit a non- or hypo-response to the HBV vaccine. Genetic variations associated with T cell immunity contribute to the immune response to HBV vaccination. The deltex 1 (DTX1) gene is involved in T cell anergy, which may also be associated with the immune response to the HBV vaccination. METHODS: We detected 10 single nucleotide polymorphisms (SNPs) in or around the DTX1 gene in 601 infants out of a population from Southwest China, including 299 high responders(HRs; HBsAb > 100 mIU/mL) and 302 non-responders (NRs; HBsAb < 10 mIU/mL). An additional validation study was performed, comprising 230 adult patients(135 HRs and 95 NRs) from Southwest China. RESULTS: This study found that the minor allele 'G' of rs2384077 (adjusted p = 2.63E(-04)), and the minor allele 'C' of rs10744794 (adjusted p = 3.69E(-04)) in the first intron of the DTX1 gene were remarkably associated with the immune response to HBV vaccination in both infant and adult populations. Moreover, a subsequent analysis indicated that haplotypes (A-T, G-C) of the two SNPs were significantly associated with the immune response to HBV vaccination. CONCLUSIONS: Two SNPs (rs2384077 and rs10744794) in an intron of DTX1 and the linkage disequilibrium (LD) block are significantly associated with the immune response to HBV vaccination. The functional element annotation of the LD block between the two SNPs contains four transcriptional regulatory elements. The results suggest that these two SNPs may be involved in the immune response to HBV vaccination.

Efficacy of immunosuppression monotherapy after liver transplantation: a meta-analysis.

AIM: To assess the advantages and disadvantages of immunosuppression monotherapy after transplantation and the impact of monotherapy on hepatitis C virus (HCV) recurrence. METHODS: Articles from Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded, including non-English literature identified in these databases, were searched up to January 2013. We included randomized clinical trials comparing various immunosuppression monotherapy and prednisone-based immunosuppression combinations for liver transplantation. The modified Jadad scale score or the Oxford quality scoring system was used. Meta-analyses were performed with weighted random-effects models. RESULTS: A total of 14 randomized articles including 1814 patients were identified. Eight trials including 1214 patients compared tacrolimus monotherapy (n = 610) vs tacrolimus plus steroids or triple therapy regarding acute rejection and adverse events (n = 604). Five trials, including 285 patients, compared tacrolimus monotherapy (n = 143) vs tacrolimus plus steroids or triple therapy regarding hepatitis C recurrence (n = 142). Four trials including 273 patients compared cyclosporine monotherapy (n = 148) vs cyclosporine and steroids regarding acute rejection and adverse events (n = 125). Two trials including 170 patients compared mycophenolate mofetil monotherapy (n = 86) vs combinations regarding acute rejection (n = 84). There were no significant differences in the acute rejection rates between tacrolimus monotherapy (RR = 1.04, P = 0.620), and cyclosporine monotherapy (RR = 0.89, P = 0.770). Mycophenolate mofetil monotherapy had a significant increase in the acute rejection rate (RR = 4.50, P = 0.027). Tacrolimus monotherapy had no significant effects on the recurrence of hepatitis C (RR = 1.03, P = 0.752). More cytomegalovirus infection (RR = 0.48, P = 0.000) and drug-related diabetes mellitus (RR = 0.54, P = 0.000) were observed in the immunosuppression combination therapy groups. CONCLUSION: Tacrolimus and cyclosporine monotherapy may be as effective as immunosuppression combination therapy. Mycophenolate mofetil monotherapy was not considerable. Tacrolimus monotherapy does not increase recurrence of HCV.

CCAAT/enhancer-binding protein ß regulates interleukin-6-induced transmembrane and ubiquitin-like domain containing 1 gene expression in hepatocytes.

Transmembrane and ubiquitin-like domain containing 1 (Tmub1) protein has a negative effect on liver regeneration; however, the mechanisms of Tmub1 expression regulation are currently unknown. CCAAT/enhancer-binding protein ß (C/EBPß) is a key transcription factor associated with interleukin-6 (IL-6) in liver regeneration. The present study aimed to investigate the involvement of C/EBPß in the IL-6­induced upregulation of Tmub1. A series of Tmub1 luciferase reporter vectors were constructed to detect the effects of IL­6 on the transcriptional activity of Tmub1. Small interfering RNA and overexpression vectors were employed to either inhibit or enhance the expression of C/EBPß, respectively, to determine the effect of C/EBPß on Tmub1 expression in liver cells. Additionally, chromatin immunoprecipitation experiments were performed to determine whether C/EBPß bound to the Tmub1 gene, and the sequences associated with the regulation of Tmub1 expression by C/EBPß were subsequently determined. Several potential binding sites of C/EBPß were identified in the 5'­upstream region of the Tmub1 gene. C/EBPß expression was positively correlated with Tmub1 gene expression in rat liver cells. Furthermore, it was demonstrated that C/EBPß bound to 5'­upstream sequences of the Tmub1 gene to enhance the promoter activity. The present study demonstrated that C/EBPß is a key transcription factor, which can positively regulate the expression of Tmub1 during liver cell proliferation through a possible association with IL-6.

Recombinant adenovirus encoding FAT10 small interfering RNA inhibits HCC growth in vitro and in vivo.

Hepatocellular carcinoma is an aggressive and rapidly fatal malignancy representing the common cancer worldwide. The specific cellular gene involved in carcinogenesis has not been fully characterized. The ubiquitin-like modifier FAT10, recently reported to be overexpressed in 90% of hepatocellular carcinoma carcinomas, was attributed to transcriptional upregulation upon the loss of p53 and induced chromosome instability in long-term in vitro culture. However, the exact function of FAT10 in hepatocellular carcinoma is not clear. In the present study, we utilized adenovirus-mediated RNA interference to knock down FAT10 expression in hepatocellular carcinoma cells and observed its effects on hepatocellular carcinoma cell growth in vitro and in vivo. The results demonstrated that interference of FAT10 could inhibit cell proliferation by inhibiting the cell cycle S-phase entry and inducing cell apoptosis. In addition, in vivo experiments showed that adenovirus Ad-siRNA/FAT10 significantly suppressed tumor growth and prolonged the lifespan of tumor-bearing mice. These results suggest that knockdown of FAT10 by adenovirus-delivered siRNA may be a promising therapeutical strategy for treatment of hepatocellular carcinoma.

Association of XRCC1 gene single nucleotide polymorphisms and susceptibility to pancreatic cancer in Chinese.

The human X-ray repair cross-complementing group 1 gene (XRCC1) is an important candidate gene for affecting pancreatic cancer (PC) risk. The objective of this study was to detect whether the c.1471G > A and c.1686C > G polymorphisms of XRCC1 gene influence PC risk. The association of XRCC1 genetic variants with PC risk was analyzed in 328 PC patients and 350 controls by the polymerase chain reaction-restriction fragment length polymorphism and created restriction site-polymerase chain reaction method. Our data suggested that the genotypes and alleles from these two genetic variants were statistically associated with PC risk. For c.1471G > A, the AA genotype was associated with the decreased risk of developing PC compared to GG wild genotype (odds ratio (OR) = 0.43, 95% confidence intervals (CI) 0.26-0.70, chi-squared (χ(2)) = 11.91, P = 0.001). For c.1686C > G, the risk of PC was significantly lower for GG genotype in comparing to CC wild genotype (OR = 0.48, 95% CI 0.29-0.81, χ(2) = 7.98, P = 0.005). The A allele of c.1471G > A and G allele of c.1686C > G genetic variants could contribute to decrease the risk of PC (for c.1471G > A: A vs G, OR = 0.65, 95% CI 0.52-0.82, χ(2) = 13.71, P < 0.001, for c.1686C > G: G vs C, OR = 0.70, 95% CI 0.55-0.88, χ(2) = 9.42, P = 0.002). Our findings indicate that the c.1471G > A and c.1686C > G polymorphisms of XRCC1 gene are associated with PC risk in Chinese population.

Association between TCF7L2 gene polymorphism and cancer risk: a meta-analysis.

OBJECTIVE: The transcription factor 7-like 2 (TCF7L2) gene has been suggested to play an important role in the pathogenesis of cancer. However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the associations between TCF7L2 polymorphism and cancer risk. METHODS: Published literature from PubMed and EMBASE were retrieved. Pooled odds ratios (ORs) with 95% confidence interval (CIs) were calculated using fixed- or random-effects model. RESULTS: A total of 19 studies (14,814 cases and 33,856 controls) were identified for the analysis of the association between TCF7L2 polymorphism and cancer risk. The results showed that TCF7L2 polymorphism was associated with breast cancer (Homogeneous model: OR=1.17, 95%CI=1.02-1.35, I (2) =21.8%, p for heterogeneity=0.276; Heterogeneous model: OR=1.11, 95%CI=1.03-1.20, I (2) =0.0%, p for heterogeneity=0.543), prostate cancer (Homogeneous model: OR=0.89, 95%CI=0.84-0.96, I (2) =0.0%, p for heterogeneity=0.640; Heterogeneous model: OR=0.89, 95%CI=0.84-0.95, I (2) =0.0%, p for heterogeneity=0.871), and colon cancer (Heterogeneous model: OR=1.15, 95%CI=1.01-1.31, I (2) =0.0%, p for heterogeneity=0.658), but not with colorectal cancer, lung cancer, and ovarian cancer. CONCLUSIONS: The present meta-analysis indicated that there were significantly associations between the TCF7L2 rs7903146 polymorphism and risk of breast, prostate and colon cancers, rather than colorectal cancer, lung cancer, and ovarian cancer.

Direct TGF-ß1 signaling between activated platelets and pancreatic cancer cells primes cisplatin insensitivity.

The exact mechanisms underlying chemotherapy insensitivity in pancreatic cancer remain largely unclear. The dynamic cross talk between tumors and their microenvironment is an important determinant of cancer chemosensitivity. However, whether additional signals provided during the intravascular transit of tumor cells affect the sensitivity of pancreatic cancer cells to chemotherapy is unknown. We have found that activated platelet-cancer cell interactions are sufficient to prime cisplatin (CDDP) insensitivity in pancreatic cancer cells. Activated platelet-derived TGF-ß1 rather than direct platelet-tumor cell contacts stimulates PI3K/Akt and MEK/Erk signaling in pancreatic cancer cells, resulting in reduction of CDDP sensitivity in these cells. Therefore, the platelet-tumor cell interactions and the relevant signaling pathways that prime CDDP insensitivity may be potential targets for adjuvant chemotherapy for pancreatic cancer.

Relationship between XRCC1 and XPD polymorphisms and the risk of the development of hepatocellular carcinoma: A case-control study.

Hepatocellular carcinoma (HCC) is a serious public health issue, the incidence of which is considered to be closely related to tobacco smoking, alcohol consumption, hepatitis B virus (HBV) infection and family history. The DNA repair system is an important protective mechanism against the development of malignant cells induced by internal and external environmental factors. The aim of this study was to investigate the association of polymorphisms of XRCC1-194, XRCC1-280 and XPD-312 DNA repair genes and the risk of development of HCC in Han Chinese patients. A case-control design was used including 252 HCC inpatients and 250 healthy controls recruited and matched by age, gender, tobacco smoking, alcohol consumption, HBV infection and family history. XPD Asp312Asn, XRCC1 Arg194Trp and XRCC1 Arg280His genes were examined using a sequencing assay method. Distributions of the genotype frequency and odds ratio (OR) between the two groups were analyzed. The results demonstrated that there was no significant difference in the frequencies of XPD Asp312Asn, XRCC1 Arg194Trp and XRCC1 Arg280His in the HCC cases and the control group. In the stratified analysis of different allele genotypes, the frequency of the XRCC1-194 site genotype was not significantly different between the case and control group. The presence of the XRCC1 280His genotype was associated with a significantly increased risk of HCC under conditions of HBV infection and family history [OR (95% CI): 1.68 (1.08-2.60), 4.20 (1.34-13.20), respectively]. Similarly, the XPD 312Asn significantly increased the risk of HCC under conditions of alcohol consumption, tobacco smoking, HBV infection and family history [OR (95% CI): 1.67 (1.10-2.60), 1.87 (1.18-2.96), 1.96 (1.24-3.10), 3.40 (1.32-8.76), respectively]. In conclusion, tobacco smoking and alcohol consumption are high risk factors of HCC for the XPD 312Asn genotype; HBV infection and family history increase the risk of HCC for the genotypes XRCC1 280His and XPD 312Asn.

Overexpression of the structural maintenance of chromosome 4 protein is associated with tumor de-differentiation, advanced stage and vascular invasion of primary liver cancer.

Structural maintenance of chromosome 4 (SMC4) is associated with tumorigenesis. The present study aimed at detecting SMC4 expression in primary liver cancer and its association with clinicopathological patient data. A total of 72 primary liver cancer tissues and 6 liver cell lines were assessed for expression of SMC4 mRNA and protein with qRT-PCR, western blotting and immunohistochemistry, respectively. SMC4 siRNAs were constructed to knockdown SMC4 expression, and phenotypic changes of hepatocellular carcinoma (HCC) cells were analyzed using flow cytometry and cell viability assays. The data showed that SMC4 mRNA and protein were highly expressed in HCC tissues compared to the normal tissues. Immunohistochemical analysis revealed that 52 of 72 (72.2%) paraffin-embedded primary liver cancer tissues displayed strong cytoplasmic staining of SMC4 protein, whereas only 6 (8.3%) normal liver tissues showed immunostaining of SMC4. Statistical analysis showed that SMC4 expression was significantly associated with tumor size, de-differentiation, advanced stages and vascular invasion of the primary liver cancers. Moreover, knockdown of SMC4 expression reduced HCC cell proliferation. These data demonstrated that expression of SMC4 protein may be useful for the early detection and prediction of primary liver cancer progression.

Polymorphisms of base-excision repair genes hOGG1 326cys and XRCC1 280His increase hepatocellular carcinoma risk.

BACKGROUND: DNA base-excision repair genes hOGG1 and XRCC1 play an important role in preserving genetic stability in mammalian cells against any damage caused by different factors. However, it is unclear whether altered expression and function of these DNA repair genes could lead to hepatocellular carcinoma (HCC) susceptibility. AIMS: This study determined the association between polymorphisms of the genes encoding two key proteins of DNA base excision repair (hOGG1 ser326Cys and XRCC1 Arg 280His) and HCC risk. METHODS: A total of 350 HCC patients (mean age of 51.1 years) and 400 healthy controls (mean age of 51.4 years) were recruited for analysis of XRCC1 and hOGG1 gene polymorphisms using PCR plus restriction fragment length polymorphism (PCR-RFLP). RESULTS: The data showed that the hOGG1 Cys326Cys and Ser326Cys genotypes were associated with increase in HCC risk. In contrast, there was no association between HCC susceptibility and the distribution of XRCC1 His 280 His and Arg280His. However, combination of these two gene polymorphisms (XRCC1-280 Arg and hOGG1-326Cys) is associated with significant induction of HCC risk. In addition, the data also showed that XRCC1 280His polymorphism was associated with HBV infection and HCC family history to increase HCC risk. The hOGG1 326cys genotype was associated with alcohol consumption, tobacco smoke, and HBV infection to increase HCC risk. CONCLUSION: The data from the current study demonstrated the association of these two DNA repair gene polymorphisms with HCC risk. Future studies will confirm these data before they can be used as a biomarker for assessing HCC risk.

IL-6 induction of hepatocyte proliferation through the Tmub1-regulated gene pathway.

The expression of transmembrane and ubiquitin-like domain containing 1 (Tmub1) is upregulated during liver regeneration, however, the function and underlying molecular mechanisms responsible for Tmub1 action remain to be determined. This study utilized BRL-3A rat liver cells for Tmub1 shRNA lentivirus infection and IL-6 stimulation. Semi-quantitative RT-PCR and western blot analysis were used to detect mRNA and protein expression levels, respectively. A [3H]thymidine incorporation assay was performed to assess changes in cell proliferation rates. Laser scanning confocal microscopy and immunoprecipitation-western blotting were used to assess the interaction between Tmub1 and calcium-modulating cyclophilin ligand (CAML) protein. The effect of Tmub1 on calcium ion influx into BRL-3A cells was measured by inverted fluorescence microscopy. The data showed that IL-6 treatment induced proliferation of rat hepatocytes and expression of Tmub1 mRNA and protein, while Tmub1 shRNA knocked down Tmub1 expression at both the mRNA and protein levels. Furthermore, compared to the negative control, Tmub1 shRNA-infected BRL-3A cells were highly proliferative with or without IL-6 stimulation. Tmub1 is colocalized with CAML in the hepatocellular cytoplasm, whereas knockdown of Tmub1 expression upregulated expression of CAML protein. Influx of Ca2+ into rat liver cells was also affected after Tmub1 knockdown. The data from the current study demonstrate that Tmub1 plays a negative role in IL-6-induced hepatocyte proliferation, and indicate that the interaction between Tmub1 and CAML may mediate the function of Tmub1 in hepatocytes.

Biliary leakage might promote liver regeneration following hepatectomy.

The biliary leakage is a common and even lethal postoperative complication to the patients after hepatectomy. However, we found that the patients who underwent this lethal postoperative complication could potentially acquire a faster restoration of remnant liver volume comparing with those without postoperative biliary leakage. We surmise that inflammatory response induced by biliary leakage after partial hepatectomy may be the one of reasons for this phenomenon. Abnormal levels of TNF-alpha, IL-6, and STAT3 caused by biliary leakage may be a main reason for fast liver regeneration. On the other hand, we hypothesize that biliary leakage may promote liver regeneration by activating the immune system after partial hepatectomy. Our hypothesis might provide a novel therapeutic strategy for patients who underwent liver failure after partial hepatectomy. For instance, the exogenous infection or controlling biliary leakage may be reasonable and deserve further study. With the aid of animal model of postoperative biliary leakage or intraabdominal bacterial infections, this hypothesis could be partially or fully confirmed.