Polymorphism of glutathione S-transferase mu 1 and theta 1 genes and hepatocellular carcinoma in southern Guangxi, China

AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and hepatocellular carcinoma (HCC) risk. METHODS: The genetic polymorphisms were studied at an aflatoxin highly contaminated region in Guangxi, China. Pdymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in blood samples. The case group was composed of 181 patients of HCC identified by the pathologists and the control group was composed of 360 adults without any tumor. RESULTS: The frequencies of GSTM1 and GSTT1 null genotypes in the control were 47.8% and 42.7%, while those in the HCC group were 64.6% and 59.7%, respectively. The differences between HCC group and control group were very significant (P<0.01). GSTM1 and GSTT1 combined null genotypes in HCC group and control group were 38.2% and 18.5% respectively, and the difference was significant (P<0.05). CONCLUSION: The GSTM1 and GSTT1 null genotypes are associated with an increased risk of HCC in a special geographic environment. Combination of the two null genotypes in an individual is substantially increased twice the risk of HCC.

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

Background:Hepatocellular carcinoma(HCC),the most common type of primary liver cancer,is the fourth leading cause of cancer-related deaths worldwide.Previous evidence shows that the expression of circulating RNA ZFR(circZFR)is upregulated in HCC tissues.However,the molecular mechanism of circZFR in HCC is unclear.Methods:Quantitative reverse transcriptase polymerase chain reaction(qRT-PCR)was employed to detect the expression of circZFR,microRNA-624-3p(miR-624-3p)and WEE1 in HCC tissues and cells.RNase R assay and actinomycin D treatment assay were used to analyze the characteristics of circZFR.For functional analysis,the capacities of colony formation,cell proliferation,cell apoptosis,migration and invasion were assessed by colony formation assay,5-ethynyl-2-deoxyuridine(EdU)assay,flow cytometry assay and transwell assay.Western blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition(EMT)-related proteins.The interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation(RIP)assay.Xenograft models were established to determine the role of circZFR in vivo.Results:circZFR and WEE1 were upregulated,while miR-624-3p expression was reduced in HCC tissues and cells.circZFR could sponge miR-624-3p,and WEE1 was a downstream gene of miR-624-3p.Knockdown of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR624-3p inhibitor restored this change.Overexpression of WEE1 abolished the inhibitory effect of miR624-3p mimic on HCC cells.Mechanistically,circZFR acted as a competitive endogenous RNA(ceRNA)to regulate WEE1 expression by targeting miR-624-3p.Furthermore,in vivo studies have illustrated that circZFR knockdown inhibited tumor growth.Conclusions:circZFR knockdown reduced HCC cell proliferation,migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis,suggesting that the circZFR/miR-624-3p/WEE1 axis might be a potential target for HCC treatment.

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

Objective Hepatocellular carcinoma(HCC)is the third leading cause of cancer-associated death worldwide.As a first-line drug for advanced HCC treatment,lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients,and the underlying mechanism remains largely unknown.The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC,explore the potential molecular mechanism,and propose combinatorial therapeutic targets for HCC management.Methods Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol.RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant(LR)cells.The upregulated genes were analyzed by GO and KEGG analyses.Then,qPCR and Western blotting were employed to determine the relative gene expression levels.Afterwards,the intracellular reactive oxygen species(ROS)and apoptosis were detected by flow cytometry.Results PLC-LR and Hep3B-LR were established.There was a total of 116 significantly upregulated genes common to both LR cell lines.The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities,and reactive oxygen species pathways.Notably,NAD(P)H:quinone oxidoreductase 1(NQO1)was highly expressed in LR cells,and was involved in the lenvatinib resistance.The high expression of NQO1 decreased the production of ROS induced by lenvatinib,and subsequently suppressed the apoptosis.The combination of lenvatinib and NQO1 inhibitor,dicoumarol,reversed the resistance of LR cells.Conclusion The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels,thereby promoting lenvatinib resistance in HCC cells.

Long noncoding RNAs HAND2-AS1 ultrasound microbubbles suppress hepatocellular carcinoma progression by regulating the miR-873-5p/tissue inhibitor of matrix metalloproteinase-2 axis

BACKGROUND Increasing data indicated that long noncoding RNAs(lncRNAs)were directly or indirectly involved in the occurrence and development of tumors,including hepatocellular carcinoma(HCC).Recent studies had found that the expression of lncRNA HAND2-AS1 was downregulated in HCC tissues,but its role in HCC progression is unclear.Ultrasound targeted microbubble destruction mediated gene transfection is a new method to overexpress genes.AIM To study the role of ultrasound microbubbles(UTMBs)mediated HAND2-AS1 in the progression of HCC,in order to provide a new reference for the treatment of HCC.METHODS In vitro,we transfected HAND2-AS1 siRNA into HepG2 cells by UTMBs,and detected cell proliferation,apoptosis,invasion and epithelial-mesenchymal transition(EMT)by cell counting kit-8 assay,flow cytometry,Transwell invasion assay and Western blotting,respectively.In addition,we transfected miR-837-5p mimic into UTMBs treated cells and observed the changes of cell behavior.Next,the UTMBs treated HepG2 cells were transfected together with miR-837-5p mimic and tissue inhibitor of matrix metalloproteinase-2(TIMP2)overexpression vector,and we detected cell proliferation,apoptosis,invasion and EMT.In vivo,we established a mouse model of subcutaneous transplantation of HepG2 cells and observed the effect of HAND2-AS1 silencing on tumor formation ability.RESULTS We found that UTMBs carrying HAND2-AS1 restricted cell proliferation,invasion,and EMT,encouraged apoptosis,and HAND2-AS1 silencing eliminated the effect of UTMBs.Additionally,miR-873-5p targets the gene HAND2-AS1,which also targets the 3’UTR of TIMP2.And miR-873-5p mimic counteracted the impact of HAND2-AS1.Further,miR-873-5p mimic solely or in combination with pcDNA-TIMP2 had been transformed into HepG2 cells exposed to UTMBs.We discovered that TIMP2 reversed the effect of miR-873-5p mimic caused by the blocked signalling cascade for matrix metalloproteinase(MMP)2/MMP9.In vivo results showed that HAND2-AS1 silencing significantly inhibited tumor formation in mice.CONCLUSION LncRNA HAND2-AS1 promotes TIMP2 expression by targeting miR-873-5p to inhibit HepG2 cell growth and delay HCC progression.

STUDY OF THE DELETION MUTATION OF GLUTATHIONE S TRANSFERASE M1 GENE AND ITS ROLE IN SUSCEPTIBILITYTO HEPATOCELLULAR CARCINOMA

Objection: To investigate the glutathione S transferase M1 (GSTM1) gene inherent deletion and its relation to prevalence of hepatocellular carcinoma (HCC) in Guangxi, China. Methods: The GSTM1 gene polymorphism of 120 HCC patients and 100 healthy subjects both from the same high aflatoxin B1 (AFB1) contaminated area were detected using PCR technique with special primers. Another 40 patients from AFB1 low risk area were also tested. Results: In HCC high risk area, it was found that the frequencies of GSTM1 null genotype in HCC patients and healthy subjects were 59% and 51% respectively, with no significant difference. However, the frequency of GSTM1-null genotype in control group from AFB1 low risk area was lower than those from high risk area (P<0.01). Conclusion: Populations in this HCC endemic region show a higher rate of GSTM1-null genotype, which may be partially responsible for the susceptibility to AFB1 induced HCC. But the detoxification effect of GSTM1 alone is not sufficient to resist the genetic toxicity of AFB1, especially in those people who expose to excess AFB1. The GSTM1 gene deletion would not be suitable as an independent predictor of susceptibility to HCC.

Molecular mechanism underlying the functional loss of cyclindependent kinase inhibitors p16 and p27 in hepatocellular carcinoma

Hepatocellular carcinoma （HCC） is one of the most common human cancers, and its incidence is still increasing in many countries. The prognosis of HCC patients remains poor, and identification of useful molecular prognostic markers is required. Many recent studies have shown that functional alterations of cellcycle regulators can be observed in HCC. Among the various types of cell-cycle regulators, p16 and p27 are frequently inactivated in HCC and are considered to be potent tumor suppressors, p16, a G1-specific cell-cycle inhibitor that prevents the association of cyclindependent kinase （CDK） 4 and CDK6 with cyclin DI, is frequently inactivated in HCC via CpG methylation of its promoter region, p16 may be involved in the early steps of hepatocarcinogenesis, since p16 gene methylation has been detected in subsets of pre-neoplastic liver cirrhosis patients, p27, a negative regulator of the G1-S phase transition through inhibition of the kinase activities of Cdk2/cyclin A and Cdk2/cyclin E complexes, is now considered to be an adverse prognostic factor in HCC. In some cases of HCC with increased cell proliferation, p27 is overexpressed but inactivated by sequestration into cyclin D1-CDK4-containing complexes. Since loss of p16 is closely related to functional inactivation of p27 in HCC, investigating both p16 and p27 may be useful for precise prognostic predictions in individuals with HCC.

Immunohistochemical analysis of p53,cyclinD1,RB1,c-fos and N-ras gene expression in hepatocellular carcinoma in Iran

AIM： TO study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS： Paraffin-embedded tissue samples of 25 patients （18 males and 7 females） with hepatocellular carcinoma were collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method （avidin-biotin-peroxidase） for detection of p53, cyclinD1, RB1, c-los and N-ras proteins. RESULTS： Six （24%）, 5 （20%）, 12 （48%） and 2 samples （8%） were positive for p53, cyclinDl, C-los and N-ras expression, respectively. Twenty-two （88%） samples had alterations in the （31 cell-cycle checkpoint protein expression （RBI or cyclinD1）. P53 positive samples showed a higher （9 times） risk of being positive for RBI protein than p53 negative samples. Loss of expression of RBI in association with p53 over-expression was observed in 4 （66.7%） of 6 samples. Loss of expression of RBI was seen in all cyclinD1 positive, 20 （90.9%） N-ras negative, and ii （50%） C-fos positive samples, respectively. CyclinD1 positive samples showed a higher （2.85 and 4.75 times） risk of being positive for c-los and N-ras expression than cyclinD1 negative samples. CONCLUSION： The expression of p53, RB1 and c-los genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated with their loss of expression during development of hepatocellular carcinoma.

Expression and clinical significance of p53,JunB and KAI1/CD82 in human hepatocellular carcinoma

BACKGROUND: The mechanism of regulation of KAI1, a specific tumor metastasis suppression gene, is controversial. A recent study showed that the synergism of wild-type p53 and JunB has the function of regulating the expression of KAI1, a metastasis inhibiting factor in prostate cancer cells. The wild-type p53 gene is an activator of apoptosis and is closely related to malignant tumor cell multiplication. JunB, a member of the fos/jun family, is a key component of activator protein transcription factor and a major target element in the transmission pathway of mitosis. This study aimed to evaluate the relationship between the expression of KAI1 and p53 combined with JunB in tumor tissues and clinical outcomes in hepatocellular carcinoma (HCC) patients. METHODS: Quantitative real-time RT-PCR, Western blotting techniques and immunohistochemistry were used to evaluate the expression of KAI1 mRNA, KAI1/CD82, p53 and JunB in HCC patients, and the relationship between their expression and the clinicopathological prognostic parameters was analyzed. RESULTS: In cancer tissues, the values for positive expression of KAI1 mRNA, KAI1/CD82, p53 and JunB were 31.25%, 26.25%, 48.75%, and 20.00%, respectively, while in adjacent non-tumor tissues, they were 100%, 94.74%, 2.63%, and 76.32%, respectively. There was no correlation between the expression levels of p53 or JunB and KAI1 mRNA or KAI1/CD82. However, there were significant correlations between the expression levels of p53 combined with JunB and not only KAI1 mRNA but also KAI1/CD82 proteins. CONCLUSIONS: When p53 dysfunction and low expression of JunB are simultaneous, they may play an important role in down-regulating the expression of KAI1 by synergism in HCC. But further studies in vivo and in vitro are needed to verify these results.

Dual targeting of Polo-like kinase 1 and baculoviral inhibitor of apoptosis repeat-containing 5 in TP53-mutated hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC),often diagnosed at advanced stages without curative therapies,is the fifth most common malignant cancer and the second leading cause of cancer-related mortality.Polo-like kinase 1(PLK1)is activated in the late G2 phase of the cell cycle and is required for entry to mitosis.Interestingly,PLK1 is overexpressed in many HCC patients and is highly associated with poor clinical outcome.Baculoviral inhibitor of apoptosis repeatcontaining 5(BIRC5)is also highly overexpressed in HCC and plays key roles in this malignancy.AIM To determine the expression patterns of PLK1 and BIRC5,as well as their correlation with p53 mutation status and patient clinical outcome.METHODS The expression patterns of PLK1 and BIRC5,and their correlation with p53 mutation status or patient clinical outcome were analyzed using a TCGA HCC dataset.Cell viability,cell apoptosis,and cell cycle arrest assays were conducted to investigate the efficacy of the PLK1 inhibitors volasertib and GSK461364 and the BIRC5 inhibitor YM155,alone or in combination.The in vivo efficacy of volasertib and YM155,alone or in combination,was assessed in p53-mutated Huh7-derived xenograft models in immune-deficient NSIG mice.RESULTS Our bioinformatics analysis using a TCGA HCC dataset revealed that PLK1 and BIRC5 were overexpressed in the same patient subset and their expression was highly correlated.The overexpression of both PLK1 and BIRC5 was more frequently detected in HCC with p53 mutations.High PLK1 or BIRC5 expression significantly correlated with poor clinical outcome.PLK1 inhibitors(volasertib and GSK461364)or a BIRC5 inhibitor(YM155)selectively targeted Huh7 cells with mutated p53,but not HepG2 cells with wild-type p53.The combination treatment of volasertib and YM155 synergistically inhibited the viability of Huh7 cells via apoptotic pathway.The efficacy of volasertib and YM155,alone or in combination,was validated in vivo in a Huh7-derived xenograft model.CONCLUSION PLK1 and BIRC5 are highly co-expressed in p53-mutated HCC and inhibition of both PLK1 and BIRC5 synergistically compromises the viability of p53-mutated HCC cells in vitro and in vivo.

CMA down-regulates p53 expression through degradation of HMGB1 protein to inhibit irradiation-triggered apoptosis in hepatocellular carcinoma

AIM To investigate the mechanism of chaperone-mediated autophagy(CMA)-induced resistance to irradiationtriggered apoptosis through regulation of the p53 protein in hepatocellular carcinoma(HCC). METHODS Firstly, we detected expression of lysosome-associated membrane protein 2a(Lamp-2a), which is the key protein of CMA, by western blot in Hep G2 and SMMC7721 cells after irradiation. We further used sh RNA Lamp-2a HCC cells to verify the radioresistance induced by CMA. Next, we detected the HMGB1 and p53 expression after irradiation by western blot, and we further used RNA interference and ethyl pyruvate(EP), as a HMGB1 inhibitor, to observe changes of p53 expression. Finally, an immunoprecipitation assay was conducted to explore the interaction between Lamp-2a and HMGB1, and the data were analyzed. RESULTS We found the expression of Lamp-2a was increased on irradiation while apoptosis decreased in Hep G2 and SMMC7721 cells. The apoptosis was increased markedly in the sh RNA Lamp-2a Hep G2 and SMMC7721 cells as detected by western blot and colony formation assay. Next, we found p53 expression was gradually reduced on irradiation but obviously increased in sh RNA Lamp-2a cells. Furthermore, p53 increased the cell apoptosis on irradiation in Hep3B(p53-/-) cells. Finally, p53 levels were regulated by HMGB1 as measured through RNA interference and the EP treatment. HMGB1 was able to combine with Lamp-2a as seen by immunoprecipitation assay and was degraded via the CMA pathway. The decreased HMGB1 inhibited p53 expression induced by irradiation and further reduced the apoptosis in HCC cells. CONCLUSION CMA pathway activation appears to down-regulate the susceptibility of HCC to irradiation by degrading HMGB1 with further impact on p53 expression. These findings have clinical relevance for radiotherapy of HCC.

Pivotal role of long non-coding ribonucleic acid-X-inactive specific transcript in regulating immune checkpoint programmed death ligand 1 through a shared pathway between miR-194-5p and miR-155-5p in hepatocellular carcinoma

BACKGROUND Anti-programmed death therapy has thrust immunotherapy into the spotlight.However,such therapy has a modest response in hepatocellular carcinoma(HCC).Epigenetic immunomodulation is a suggestive combinatorial therapy with immune checkpoint blockade.Non-coding ribonucleic acid(ncRNA)driven regulation is a major mechanism of epigenetic modulation.Given the wide range of ncRNAs that co-opt in programmed cell-death protein 1(PD-1)/programmed death ligand 1(PD-L1)regulation,and based on the literature,we hypothesized that miR-155-5p,miR-194-5p and long non-coding RNAs(lncRNAs)X-inactive specific transcript(XIST)and MALAT-1 are involved in a regulatory upstream pathway for PD-1/PD-L1.Recently,nutraceutical therapeutics in cancers have received increasing attention.Thus,it is interesting to study the impact of oleuropein on the respective study key players.AIM To explore potential upstream regulatory ncRNAs for the immune checkpoint PD-1/PD-L1.METHODS Bioinformatics tools including microrna.org and lnCeDB software were adopted to detect targeting of miR-155-5p,miR-194-5p and lncRNAs XIST and MALAT-1 to PD-L1 mRNA,respectively.In addition,Diana tool was used to predict targeting of both aforementioned miRNAs to lncRNAs XIST and MALAT-1.HCC and normal tissue samples were collected for scanning of PD-L1,XIST and MALAT-1 expression.To study the interaction among miR-155-5p,miR-194-5p,lncRNAs XIST and MALAT-1,as well as PD-L1 mRNA,a series of transfections of the Huh-7 cell line was carried out.RESULTS Bioinformatics software predicted that miR-155-5p and miR-194-5p can target PDL1,MALAT-1 and XIST.MALAT-1 and XIST were predicted to target PD-L1 mRNA.PD-L1 and XIST were significantly upregulated in 23 HCC biopsies compared to healthy controls;however,MALAT-1 was barely detected.MiR-194 induced expression elevated the expression of PD-L1,XIST and MALAT-1.However,overexpression of miR-155-5p induced the upregulation of PD-L1 and XIST,while it had a negative impact on MALAT-1 expression.Knockdown of XIST did have an impact on PD-L1 expression;however,following knockdown of the negative regulator of X-inactive specific transcript(TSIX),PD-L1 expression was elevated,and abolished MALAT-1 activity.Upon co-transfection of miR-194-5p with siMALAT-1,PD-L1 expression was elevated.Co-transfection of miR-194-5p with siXIST did not have an impact on PD-L1 expression.Upon co-transfection of miR-194 with siTSIX,PD-L1 expression was upregulated.Interestingly,the same PD-L1 expression pattern was observed following miR-155-5p cotransfections.Oleuropein treatment of Huh-7 cells reduced the expression profile of PD-L1,XIST,and miR-155-5p,upregulated the expression of miR-194-5p and had no significant impact on the MALAT-1 expression profile.CONCLUSION This study reported a novel finding revealing that opposing acting miRNAs in HCC,have the same impact on PD-1/PD-L1 immune checkpoint by sharing a common signaling pathway.

P21^(WAF1/Cip1)Gene Expression in Primary Human Hepatocellular Carcinoma and its Relationship with P53 Gene Mutation

Summary: P21 WAF1/Cip1 , an inhibitor of cyclin dependent kinases, is a critical downstream effector in the P53 specfic pathway of growth control. Increased expression of P21 WAF1/Cip1 has been found to reflect the status of the P53 tumor suppressor pathway. We investigated the expression of P21 WAF1/Cip1 in a relatively small, but well characterized group consisting of 28 hepatocellular carcinomas. The samples were previously studied for P53 gene mutation. P21 WAF1/Cip1 expression were identified by in situ hybridization and immunohistochemistry. Positive ISH for P21 WAF1/Cip1 transcripts was found in 18 of 28 cases (64.3 %). All positive cases by ISH showed detectable P21 WAF1/Cip1 protein reactivity by IHC. No relationship was found between P21 WAF1/Cip1 staining and P53 mutational status. No associations were seen with tumor metastasis, size and tumor grade, except for tumor differentiation status which showed higher frequency of P21 WAF1/Cip1 expression in moderate well differentiated HCCs than poorly differentiated tumors ( P <0.05). It is concluded that expression of P21 WAF1/Cip1 is common in HCCs, but does not correlate with P53 mutational status or pathological parameters investigated except for tumor differentiation. Also, there may be other factors beside P53 that regulate P21 WAF1/Cip1 gene expression in HCCs.

Effect on Survivin Regulation of Transcription Level by p21^(waf1) Overexpression in HepG2 Hepatocellular Carcinoma Cells

The effect of cyclin-dependent kinase inhibitors Cip1/Wafl （p21） on regulatory expression of survivin transcription in human hepatocellular carcinoma cell HepG2 was observed and the related mechanisms explored. Doxorubicin （DOX） was used to treat HepG2. Eukaryotic vector pEGFP-C2-p21 was transfected into HepG2 by lipofectamine and positive clones were screened out by G418. The mRNA expression of p21 and survivin was detected by real-time fluorescent quantitative polymerase chain reaction （RQ-PCR）. Flow cytometry was used to examine the cell cycle, and reverse transcription polymerase chain reaction （RT-PCR） was used to measure the levels of E2F-1 and p300. The results showed that： （1） After treatment with DOX, the expression of p21 was increased, whereas that of survivin was reduced during 24 h of treatment; （2） After transfection of pEGFP-C2-p21 into HepG2, p21 level was significantly enhanced to 2100.11-folds or 980.89-folds in comparison to HepG2 or HepG2-C2 group, and survivin level was markedly down-regulated to 0.54% or 0.59% relative to the control groups; （3） Overexpressed p21 resulted in GI/G0 phase arrest （F=31.59, P〈0.01）, meanwhile E2F-1 mRNA and p300 mRNA were reduced as compared with those of controls （FE2F-1=I25.28, P〈0.05; Fp300= 46.01, P〈0.01）. It was suggested that p21 could be a potential mediator of survivin suppression at transcription level in HepG2 cell, which might be through the block at G1/G0 phase and down-regulation of transcription factors E2F-1 and p300.

Glutathione S-transferase M1 and T1 Gene Deletion Associated with Increased Susceptibility to Nasopharyngeal Carcinoma

Objective： To evaluate the association of Glutathione S-transferase （GST） M1 and T1 genetic polymorphisms and susceptibility to nasopharyngeal carcinoma （NPC） in a high risk area of Guangxi Zhuang Autonomous Region （province）, Southwest of China. Methods： A case-control study was conducted to investigate the genetic polymorphisms of these enzymes （GSTM1 and GSTT1 null genotypes）. A total of 127 NPC cases and 207 controls were recruited. Results： GSTM1 and GSTT1 null genotype frequencies were higher among NPC patients at a level of statistical significance （P〈0.005; P〈0.001 respectively）, and both GSTM1 and GSTT1 null genotype were even more significant （P〈0.001）. Conclusion： NPC is the most common cancer in Guangxi. GST enzymes are involved in the detoxification of many environmental carcinogens. Homozygous deletions of GSTM1 and GSTT1 have been associated with several types of cancer. The risk to develop NPC has been associated with environmental factors such as cigarette smoking and EB virus infection. The present results indicate that the GSTM1 and GSTT1 deletion polymorphisms are associated with an increase risk of susceptibility to NPC, and both detoxific enzyme genes deletion is more important than a single gene deletion for the susceptibility to NPC.

A genetic variant in pseudogene E2F3P1 contributes to prognosis of hepatocellular carcinoma

Certain pseudogenes may regulate their protein-coding cousins by competing for miRNAs and play an active biological role in cancer. However, few studies have focused on the association of genetic variations in pseudogenes with cancer prognosis. We selected six potentially functional single nucleotide polymorphisms （SNPs） in cancerrelated pseudogenes, and performed a case-only study to assess the association between those SNPs and the prognosis of hepatocellular carcinoma （HCC） in 331 HBV-positive HCC patients without surgical treatment. Log-rank test and Cox proportional hazard models were used for survival analysis. We found that the A allele of rs9909601 in E2F3P1 was significantly associated with a better prognosis compared with the G allele [adjusted hazard ratio （HR） = 0.69, 95% confidence interval （CI） = 0.56-0.86, P = 0.001]. Additionally, this protective effect was more predominant for patients without chemotherapy and transcatheter hepatic arterial chemoembolization （TACE） treatment. Interestingly, we also detected a statistically significant multiplicative interaction between genotypes of rs9909601 and chemotherapy or TACE status on HCC survival （P for multiplicative interaction 〈 0.001）. These findings indicate that rs9909601 in the pseudogene E2F3P1 may be a genetic marker for HCC prognosis in Chinese.

A MOLECULAR EPIDEMIOLOGIC MARKER OF HEPATOCELLULAR CARCINOMA FROM AFLATOXIN B1 CONTAMINATED AREA IN THE SOUTHWEST OF GUANGXI

HCC specimens from high and low AFB1 risk areas in Guangxi showed different frequency of p53 mutational hot spot, which were 20/35 (57%) and 1/10 by DNA sequencing and 36/52 (69%) and 2/10 by RFLP analysis respectively. Their differences were significant (P<0.01). Mutational points of p53 gene induced by AFB1 mutagen almost exclusively clustered at codon 249 third nucleotide and by the form of G to T transversion only. We call it 'AFB1 mutational hot spot'. It turns out to be a significant marker for molecular epidemio logic survey to decide how many HCC and which individuals are induced by AFB1 mutagen, and if emergence of this marker in HCC is frequent in certain region it indicated that there is heavy contamination by AFB1.

Double Lethal Effects of Fusion Gene of Wild-type p53 and JunB on Hepatocellular Carcinoma Cells

This study explored the double lethal effects of pEGFP-C1-wtp53/junB fusion gene on hepatocellular carcinoma (HCC) cells.wtp53/junB fusion gene was constructed and transformed into HepG2 cell line.Expression of KAI1 was detected by quantitative real-time PCR and Western blotting,cells apoptosis rate was detected by flow cytometry,proliferation of cells was detected by MTT chromometry,cell transmigration was detected by using transwell systems.The results showed that after transformation with pEGFP-C1-wtp53/JunB,the expression level of KAI1 protein was up-regulated,being 8.13 times the blank control group in HepG2 cells and significantly higher than 2.87 times which transformed with pEGFP-C1-JunB,3.11 times which transformed with pEGFP-C1-wtp53 (P<0.001).Apoptosis rate of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly higher than that of other groups (P<0.001),and invasive ability of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly lower than other groups (P<0.001).It was concluded that the fusion gene of wtp53 and JunB could not only inhibit the growth of hepatoma cells and promote tumor cell apoptosis,but also suppress the invasive ability of tumor cells by up-regulating the expression of KAI1.

Growth inhibition of hepatocellular carcinoma tumor endothelial cells by miR-204-3p and underlying mechanism

AIM: To investigate the mechanism by which miR-204-3p inhibits the growth of hepatocellular carcinoma (HCC) tumor endothelial cells (TECs).

Inhibition of apoptosis by oncogenic hepatitis B virus X protein: Implications for the treatment of hepatocellular carcinoma

Hepatitis B virus X protein(HBx) plays an important role in the development of hepatocellular carcinoma(HCC). In addition, hepatoma upregulated protein(HURP) is a cellular oncogene that is upregulated in a majority of HCC cases. We highlight here recent findings demonstrating a link between HBx, HURP and anti-apoptosis effects observed in cisplatin-treated HCC cells. We observed that Hep3B cells overexpressing HBx display increased HURP mRNA and protein levels, and show resistance to cisplatin-induced apoptosis. Knockdown of HURP in HBx-expressing cells reverses this effect, and sensitizes cells to cisplatin. The anti-apoptotic effect of HBx requires activation of the p38/MAPK pathway as well as expression of SATB1, survivin and HURP. Furthermore, silencing of HURP using short-hairpin RNA promotes accumulation of p53 and reduces cell proliferation in SK-Hep-1 cells(p53^(+/–)), whereas these effects are not observed in p53-mutant Mahlavu cells. Similarly, HURP silencing does not affect the proliferation of H1299 lung carcinoma cells or Hep3 B HCC cells which lack p53. Silencing of HURP sensitizes SK-Hep-1 cells to cisplatin. While HURP overexpression promotes p53 ubiquitination and degradation by the proteasome, HURP silencing reverses these effects. Inoculation of SK-Hep-1 cancer cells in which HURP has been silenced produces smaller tumors than control in nude mice. Besides, gankyrin, a positive regulator of the E3 ubiquitin ligase MDM2, is upregulated following HURP expression, and silencing of gankyrin reduces HURP-mediated downregulation of p53. In addition, we observed a positive correlation between HURP and gankyrin protein levels in HCC patients(r^2 = 0.778; n = 9). These findings suggest a role for the viral protein HBx and the host protein HURP in preventing p53-mediated apoptosis during cancer progression and establishment of chemoresistance.

Overexpression of P-glycoprotein in hepatocellular carcinoma and its clinical implication

INTRODUCTIONMost advanced hepatocellular garcinoma (HCC) isinsensitive to most anticancer drugs which might berelated to the high frequency of expression of themultidrug resistance-1(MDR1) gene and itsproduct,P-glycoprotein (p-gp).p-gp expressionmay also be concerned with tumor progression anddifferentiation.In the present study。