Lecithin-cholesterol acyltransferase is a potential tumor suppressor and predictive marker for hepatocellular carcinoma metastasis

BACKGROUND Hepatocellular carcinoma(HCC)is a major cause of cancer mortality worldwide,and metastasis is the main cause of early recurrence and poor prognosis.However,the mechanism of metastasis remains poorly understood.AIM To determine the possible mechanism affecting HCC metastasis and provide a possible theoretical basis for HCC treatment.METHODS The candidate molecule lecithin-cholesterol acyltransferase(LCAT)was screened by gene microarray and bioinformatics analysis.The expression levels of LCAT in clinical cohort samples was detected by quantitative realtime polymerase chain reaction and western blotting.The proliferation,migration,invasion and tumor-forming ability were measured by Cell Counting Kit-8,Transwell cell migration,invasion,and clonal formation assays,respectively.Tumor formation was detected in nude mice after LCAT gene knockdown or overexpression.The immunohistochemistry for Ki67,E-cadherin,N-cadherin,matrix metalloproteinase 9 and vascular endothelial growth factor were performed in liver tissues to assess the effect of LCAT on HCC.Gene set enrichment analysis(GSEA)on various gene signatures were analyzed with GSEA version 3.0.Three machine-learning algorithms(random forest,support vector machine,and logistic regression)were applied to predict HCC metastasis in The Cancer Genome Atlas and GEO databases.RESULTS LCAT was identified as a novel gene relating to HCC metastasis by using gene microarray in HCC tissues.LCAT was significantly downregulated in HCC tissues,which is correlated with recurrence,metastasis and poor outcome of HCC patients.Functional analysis indicated that LCAT inhibited HCC cell proliferation,migration and invasion both in vitro and in vivo.Clinicopathological data showed that LCAT was negatively associated with HCC size and metastasis(HCC size≤3 cm vs 3-9 cm,P<0.001;3-9 cm vs>9 cm,P<0.01;metastatic-free HCC vs extrahepatic metastatic HCC,P<0.05).LCAT suppressed the growth,migration and invasion of HCC cell lines via PI3K/AKT/mTOR signaling.Our results indicated that the logistic regression model based on LCAT,TNM stage and the serum level of α-fetoprotein in HCC patients could effectively predict high metastatic risk HCC patients.CONCLUSION LCAT is downregulated at translational and protein levels in HCC and might inhibit tumor metastasis via attenuating PI3K/AKT/mTOR signaling.LCAT is a prognostic marker and potential therapeutic target for HCC.

RASAL2 acts as a tumor suppressor in cervical cancer cells

This study was designed to investigate the roles of RASAL2 in cervical cancer(CC).Methods:Fifty-four CC tissues and 33 adjacent tissues were obtained from CC patients admitted to our hospital between March 2012 and June 2014.Real-time polymerase chain reaction and western blotting were performed to analyze the expression of RASAL2 mRNA and protein in these tissues,CC cell lines,and normal cervical cells.Over-expression and silencing of RASAL2 were induced after transfection,and the migration,invasion,and proliferation of the CC cell lines were examined.Results:RASAL2 mRNA and protein expressions were significantly down-regulated in CC tissues and cell lines than in adjacent tissues and normal cervical cells,respectively.While low RASAL2 expression correlated with advanced stage and metastasis of CC,its over-expression significantly inhibited proliferation and metastasis of CC cells and induced apoptosis.Under in vitro conditions,silencing of RASAL2 expression could significantly increase the proliferation,invasion,and migration of CC cells.Conclusion:RASAL2 functioned as a tumor suppressor in CC,and was down-regulated in CC tissue samples and cell lines.

Identification of a potential tumor suppressor gene, UBL3, in non-small cell lung cancer

Objective: Oncogenes have been shown to be drivers of non-small cell lung cancer(NSCLC), yet the tumor suppressing genes involved in lung carcinogenesis remain to be systematically investigated. This study aimed to identify tumor suppressing ubiquitin pathway genes(UPGs) that were critical to lung tumorigenesis.Methods: The 696 UPGs were silenced by an siRNA screening in NSCLC cells;the potential tumor suppressing UPGs were analyzed, and their clinical significance was investigated.Results: We reported that silencing of 11 UPGs resulted in enhanced proliferation of NSCLC cells, and four UPGs(UBL3, TRIM22, UBE2 G2, and MARCH1) were significantly downregulated in tumor samples compared to that in normal lung tissues and their expression levels were positively associated with overall survival(OS) of NSCLC patients. Among these genes, UBL3 was the most significant one. UBL3 expression was decreased in tumor samples compared to that in paired normal lung tissues in 59/86(68.6%) NSCLCs, was correlated with TNM stage and sex of NSCLC patients, and was significantly higher in non-smoking patients than in smoking patients. Silencing UBL3 accelerated cell proliferation and ectopic expression of UBL3 suppressed NSCLC in vitro and in vivo.Conclusions: These results showed that UBL3 represented a tumor suppressor in NSCLC and may have potential for use in therapeutics and for the prediction of clinical outcome of patients.

CHROMOSOME 3 MAY HARBOR MULTIPLE TUMOR SUPPRESSOR GENES ASSOCIATED WITH PRIMARY GLIOBLASTOMA MULTIFORME

Objective: To investigate whether deletion of chromosome 3 is involved in the carcinogenesis of primary glioblastoma multiforme (GBM) and to localize the possible common deletion region in the aforementioned chromosome. Methods: PCR based microsatellite polymorphism analyses were performed to detect loss of heterozygosity (LOH). Twenty-three loci on chromosome 3 were examined in 20 cases of GBM. Fluorescence-labeled primers and Perkin Elmer 377 DNA Sequencer were applied. Results: 50% informative cases of GBM displayed LOH on chromosome 3. 50% of informative cases displayed LOH on 3q and 35% on 3p. 25.6% of informative loci showed LOH in our series, in which frequent LOH were observed in the chromosomal region from loci D3S1614 (42.9%) to D3S1565 (35.3%) on 3q24–27 and at loci D3S1569 (35.3%) on 3q22–23 and D3S1289 (33.3%) on 3p14.1–14.3. Conclusion: Loss of genetic material on chromosome 3 may play an important part in the tumorigenesis of GBM. The chromosomal regions from loci D3S1614 to D3S1565 on 3q24–27 and at loci D3S1569 on 3q22–23 and D3S1289 on 3p14.1–14.3 are potential sites for novel tumor suppressor genes associated with GBM.

CHROMOSOME 17P MAY HARBOR MULTIPLE TUMOR SUPPRESSOR GENES ASSOCIATED WITH PRIMARY GLIOBLASTOMA MULTIFORME

Objective: To investigate whether deletion of chromosome 17 is involved in the carcinogenesis of primary glioblastoma multiforme and to localize the possible common deletion region in the aforementioned chromosome. Methods: Polymerase chain reaction-based microsatellite analysis was used to assess loss of heterozygosity (LOH) on chromosome 17 in 20 primary glioblastoma multiforme (GBM). Fifteen fluorescent dye-labeled polymorphic markers were used. Results: Thirteen of twenty (65%) GBM displayed LOH on at least one marker of chromosome 17p. Two tumors showed either LOH or non-informativeness on all markers tested. The most frequent LOH was observed at loci including D17s799 (53.3%), D17s1852 (53.8%), D17s938 (63.20/o), D17s831 (55.6%). The loci D17s831 (on 17p13) and D17s799–D17s1852 (17p11.2–p12) are distal and proximal to p53 respectively. The frequencies of LOH at all loci examined on chromosome 17q were relatively low (<30%). None of informative loci exhibited microsatellite instability in this study. Conclusion: Loss of genetic material on chromosome 17p may play an important role in the pathogenesis of GBM. Besides the well-known TSG p53 on 17p, other unknown TSCs associated with GBM may be present on the chromosomal regions 17p13 and 17p11.2–p12, which are distal and proximal to p53 respectively.

miR-153 as biomarker for cancer-functional role as tumor suppressor

MicroRNA-153(miR-153),belongs toa dass of small non-coding RNA.It is a aritical regulator of gene expression at the post-transcriptional lewel which interacts with the functional mRNA at 3UTR rgion and suppresses the expression of the mRNA.More recently,it has become apparent that dhanges in the miR-153 axpression lead to invasion,metastasis,angiogenesis and various types of tumor progression.This review summarizes the connection between dysrgulation of miR-153 and various typas of cancer progression.miR-153 regulates various signaling pathways to inhibit the proliferation and induce apoptosis in the ancer cell and also show synergistic activity with anticancer drugs.In addition to this,the oncogenic bchavior of miR-153 and their use as a potential biomarker in cancer was also reviewed.

Bioinformatics Analysis Revealed Potential Tumor Suppressors (KLF4/CGN), Oncogenes (SHH/LIF) and Biomarkers of Asian Stomach Adenocarcinoma

Stomach adenocarcinoma (STAD) is the fifth most prevalent cancer and the third leading cause of cancer-related death in the world and is more common in Asia than in most Western countries. There is an urgent need to identify potential novel oncogenes and tumor suppressor genes, and biomarkers for STAD. 6652 differentially expressed genes were identified between STAD and normal samples based on the transcriptome data analysis of the TCGA and GEO databases. 13 key modules were identified in STAD by WGCNA analysis. 293 potential STAD associated genes were identified from intersection by Venn Diagram. The 293 intersected genes were enriched in cell cortex and infection by GO and KEGG analysis. 10 hub genes were identified from PPI and Cytoscape analyses of the intersected genes. KLF4/CGN low and SHH/LIF high expression were associated with short overall survival of Asian STAD patients. Bioinformatics analysis revealed potential novel tumor suppressors (KLF4/CGN), oncogenes (SHH/LIF) and biomarkers for diagnosis, therapy and prognosis of STAD, specifically for Asian patients.

Inactivation of RASSF1A, the tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma

AIM: To evaluate the genetic and epigenetic inactivation mechanism of the RASSF1A tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma.METHODS: RT-PCR was used to investigate the transcriptional expressing and re-expression of RASSF1A.RASSF1A mutation was analyzed with SSCP and selective sequencing. PCR was performed to detect the loss of heterozygosity (LOH) at the region of chromosome 3p21.3.Genomic DNA were modificated bisulfite and the frequency of methylation of CpG islands in RASSF1A promoter were evaluated by methylation specific PCR (MS-PCR).RESULTS: In all 48 samples and one cell lines of extrahepatic cholangiocarcinoma, the RASSF1A mutation is rare (6.12%, 3/49), 33 samples (68.75%) and QBC-939cell lines (x2 = 14.270, P= 0.001＜0.01) showed RASSF1A express inactivation with LOH at microsatellite loci D3S4604. Among these 33 samples and QBC-939, 28 of 33 (84.85%) tumor samples and 1 cell lines were methylated for majority of 16 CpGs, the average frequency is 73.42%.CONCLUSION: The data we present suggest that RASSF1A which we have been searching for at 3p21.3may be one of the key tumor suppressor gene and play an important role in the pathogenesis of extrahepatic cholangiocarcinoma, and the promoter methylation and allelic loss are the major mechanism for inactivation of RASSF1A.

Promoter methylation of tumor suppressor genes in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma(ESCC) is a prevalent and fatal cancer in China and other Asian countries.Epigenetic silencing of key tumor suppressor genes(TSGs) is critical to ESCC initiation and progression.Recently,many novel TSGs silenced by promoter methylation have been identified in ESCC,and these genes further serve as potential tumor markers for high-risk group stratification,early detection,and prognosis prediction.This review summarizes recent discoveries on aberrant promoter methylation of TSGs in ESCC,providing better understanding of the role of disrupted epigenetic regulation in tumorigenesis and insight into diagnostic and prognostic biomarkers for this malignancy.

Tumor suppressor and hepatocellular carcinoma

A few signaling pathways are driving the growth of hepatocellular carcinoma.Each of these pathways possesses negative regulators.These enzymes,which normally suppress unchecked cell proliferation,are circumvented in the oncogenic process,either the overactivity of oncogenes is sufficient to annihilate the activity of tumor suppressors or tumor suppressors have been rendered ineffective.The loss of several key tumor suppressors has been described in hepatocellular carcinoma.Here,we systematically review the evidence implicating tumor suppressors in the development of hepatocellular carcinoma.

Tumor suppressor genes on frequently deleted chromosome 3p in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is among the most common malignancies in southern China.Deletion of genomic DNA,which occurs during the complex pathogenesis process for NPC,represents a pivotal mechanism in the inactivation of tumor suppressor genes (TSGs).In many circumstances,loss of TSGs can be detected as diagnostic and prognostic markers in cancer.The short arm of chromosome 3 (3p) is a frequently deleted chromosomal region in NPC,with 3p21.1-21.2 and 3p25.2-26.1 being the most frequently deleted minimal regions.In recent years,our research group and others have focused on the identification and characterization of novel target TSGs at 3p,such as RASSF1A,BLU,RBMS3,and CHL1,in the development and progression of NPC.In this review,we summarize recent findings of TSGs at 3p and discuss some of these genes in detail.A better understanding of TSGs at 3p will significantly improve our understanding of NPC pathogenesis,diagnosis,and treatment.

Science Letters:IGFBP7 plays a potential tumor suppressor role against colorectal carcinogenesis with its expression associated with DNA hypomethylation of exon 1

Insulin-like growth factor binding-protein-7 (IGFBP7) was obtained from our previous colonic adenocarcinoma (CRC) and normal mucosa suppression subtraction hybridization (SSH) cDNA libraries. By RT-PCR and immunohistochemistry, we found that IGFBP7 was overexpressed in CRC tissue compared to normal tissue. However, our in vitro experiments performed in 10 CRC cell lines showed that IGFBP7 expressed only in SW480 and Caco2 cell lines, which implied an underlying reversible regulatory mechanism. Using methylation-specific PCR (MSP) and bisulfite sodium PCR (BSP), we found that its expression was associated with DNA hypomethylation of exon1. This was further supported by the in vitro study which showed restored IGFBP7 expression after demethylation agent 5-aza-2’-deoxycytidine treatment. Correlation analysis between IGFBP7 expression and prognosis indicated that overexpression of IGFBP7 in CRC tissue correlated with favourable survival. Investigation of the func-tional role of IGFBP7 through transfection studies showed that IGFBP7 protein could inhibit growth rate, decrease colony for-mation activity, and induce apoptosis in RKO and SW620 cells, suggesting it a potential tumor suppressor protein in colorectal carcinogenesis. In conclusion, our study clearly demonstrated that IGFBP7 plays a potential tumor suppressor role against colo-rectal carcinogenesis and its expression is associated with DNA hypomethylation of exon 1.

PTEN： a default gate-keeping tumor suppressor with a versatile tail

肿瘤 suppressor PTEN 包括房间增长，生长，移植，和死亡控制许多生物过程。作为一位主人细胞的管理者， PTEN 本身也受到商讨规定保证它的合适的功能。在 PTEN 规定的缺点在 carcinogenesis 上有深刻影响。在这评论，我们简短有关 PTEN 规定讨论最近的进展并且如此的知识怎么便于我们的理解和 PTEN 的进一步的探索生物学。PTEN 的 carboxyl 尾巴，看起来与 posttranslational 规定的多重类型被联系，将在详细审查下面。进一步，当 p53 需要被激活压制 tumorigenesis (一个休眠看门人) 时， PTEN 和 p53 的比较分析建议， PTEN 可能是对癌症开发的一个组成的监视者，这样一个缺省看门人。

Recent progress in the study of methylated tumor suppressor genes in gastric cancer

Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality worldwide.The pathogenesis mechanisms of gastric cancer are still not fully clear.Inactivation of tumor suppressor genes and activation of oncogenes caused by genetic and epigenetic alterations are known to play significant roles in carcinogenesis.Accumulating evidence has shown that epigenetic silencing of the tumor suppressor genes,particularly caused by hypermethylation of CpG islands in promoters,is critical to carcinogenesis and metastasis.Here,we review the recent progress in the study of methylations of tumor suppressor genes involved in the pathogenesis of gastric cancer.We also briefly describe the mechanisms that induce tumor suppressor gene methylation and the status of translating these molecular mechanisms into clinical applications.

mi R-382 functions as a tumor suppressor against esophageal squamous cell carcinoma

AIM To explore the effect of mi R-382 on esophageal squamous cell carcinoma(ESCC) in vitro and its possible molecular mechanism.METHODS Eca109 cells derived from human ESCC and Het-1A cells derived from human normal esophageal epithelium were used. Lentivirus-mediated mi R-382 was overexpressed in Eca109 cells. The effect of mi R-382 on cell proliferation was evaluated by MTT and colony formation assay. For cell cycle analysis, cells were fixed and stained for 30 min with propidium iodide(PI) staining buffer containing 10 mg/m L PI and 100 mg/m L RNase A, and analyzed by BD FACSCalibur? flow cytometer. For cell apoptosis assay, cells were stained with an Annexin V-FITC/PI Apoptosis Detection Kit according to the manufacturer's instructions and analyzed by a dual-laser flow cytometer. Cell invasion and migration abilities were determined through use of transwell chambers, non-coated or pre-coated with matrigel. Levels of proteins related to cell growth and migration were examined by western blotting.RESULTS Endogenous mi R-382 was down-regulated in Eca109 cells compared with Het-1A. Introduction of mi R-382 not only significantly inhibited proliferation and colony formation, but also arrested cell cycle at the G2/M phase, as well as promoted apoptosis and autophagy in Eca109 cells. Migration, invasion and epithelialmesenchymal transition of Eca109 cells were suppressed by overexpressing mi R-382. Western blotting results showed that mi R-382 inhibited the phosphorylation of m TOR and 4E-BP1. CONCLUSION mi R-382 functions as a tumor suppressor against ESCC development and metastasis, and could be considered as a potential drug source for the treatment of ESCC patients.

Hepatocellular carcinoma mouse models:Hepatitis B virusassociatedhepatocarcinogenesis and haploinsufficienttumor suppressor genes

The multifactorial and multistage pathogenesis of hepatocellular carcinoma(HCC)has fascinated a wide spectrum of scientists for decades.While a number of major risk factors have been identified,their mechanistic roles in hepatocarcinogenesis still need to be elucidated.Many tumor suppressor genes(TSGs)have been identified as being involved in HCC.These TSGs can be classified into two groups depending on the situation with respect to allelic mutation/loss in the tumors:the recessive TSGs with two required mutated alleles and the haploinsufficient TSGs with one required mutated allele.Hepatitis B virus(HBV)is one of the most important risk factors associated with HCC.Although mice cannot be infected with HBV due to the narrow host range of HBV and the lack of a proper receptor,one advantage of mouse models for HBV/HCC research is the numerous and powerfulgenetic tools that help investigate the phenotypic effects of viral proteins and allow the dissection of the dose-dependent action of TSGs.Here,we mainly focus on the application of mouse models in relation to HBV-associated HCC and on TSGs that act either in a recessive or in a haploinsufficient manner.Discoveries obtained using mouse models will have a great impact on HCC translational medicine.

Tumor suppressor role of mi R-133a in gastric cancer by repressing IGF1R

AIM:To investigate the function and mechanism of mi R-133a in gastric cancer(GC)and its relationship with clinicopathological characteristics of GC.METHODS:A total of 105 GC patients who underwent surgical resection as primary treatment were selected for this study.Real-time quantitative reverse transcriptase polymerase chain(q RT-PCR)was used to examine the expression levels of mi R-133a in human GC and adjacent non-tumor tissues,as well as in GC cell lines(SGC-7901,BGC-823,MGC-803,and AGS)and a human gastric mucosal epithelial cell line(GES-1).The biological role of mi RNA(mi R)-133a was assessed in the GC cell lines using MTT,apoptosis,migration and invasion,and colony formation assays,and xenograft tumorigenesis.q RT-PCR and western blot analyses were used to evaluate the potential target gene expression of mi R-133a.Pearson’s correlation was calculated to evaluate the correlation between mi R-133a and insulinlike growth factor 1 receptor(IGF1R)expression.The regulation of IGF1R by mi R-133a was verified using the luciferase reporter assay.RESULTS:In 80%of the 105 GC patients,the mean expression of mi R-133a was significantly downregulated in tumor tissues compared with adjacent normal tissues(1.215±0.1477 vs 3.093±0.4104,P<0.0001).Downregulation of mi R-133a was significantly correlated with the degree of differentiation(P=0.01),local invasion(P=0.001)and TNM stage(P=0.02)in GC patients.Compared with a control construct,forced expression of mi R-133a in GC cell lines inhibited proliferation(0.4787±0.0219 vs 0.7050±0.0147,P=0.0013 in SGC-7901 cells;and 0.5448±0.0085vs 0.7270±0.0084,P=0.001 in MGC-803 cells);migration(0.6333±0.0233 vs 1.037±0.0584,P=0.003 in SGC-7901 cells;0.6126±0.0311 vs 1.024±0.0456,P=0.0017 in MGC-803 cells);and invasion(0.613±0.0399 vs 1.033±0.0278,P=0.0013 in SGC-7901 cells;0.7433±0.0221 vs 1.017±0.0311,P=0.002 in MGC-803 cells).It also induced apoptosis(18.19%±0.2483%vs 5.887%±0.3837%,P<0.0001 in SGC-7901 cells;22.69%±0.7846%vs9.347%±0.3012%,P<0.0001 in MGC-803 cells).Furthermore,mi R-133a inhibited tumor growth and xenograft tumorigenesis of SGC-7901 cells in vivo.In addition,we identified IGF1R as a regulatory target of mi R-133a in GC.CONCLUSION:This study suggests that mi R-133a is downregulated in GC and functions as a tumor suppressor in vitro and in vivo partly by repressing IGF1R.

Inactivation of the tumor suppressor Krüppel-like factor 6 (KLF6) by mutation or decreased expression in hepatocellular carcinomas

Background and aim: The Krüppel-like transcription factor KLF6 is a novel tumor-suppressor gene. It was inactivated in human prostate cancer and other tumors tissue, as the result of frequent mutation and loss of heterozygosity (LOH). However, there is no data reporting the levels of KLF6 both mRNA and protein in hepatocellular carcinomas (HCCs). We therefore detected mutations and expression of KLF6 in HCC tissues and further observed the effect of it on cell growth in HCC cell lines. Methods: We analyzed the exon-2 of KLF6 gene by direct DNA sequencing, and detected the expression of KLF6 by RT-PCR and Western blot in 23 HCC tissues and corresponding nontumorous tissues. Loss of growth suppressive effect of the HCC-derived KLF6 mutant was characterized by in vitro growth curves plotted, flow cytometry and Western blotting. Results: KLF6 mutations were found in 2 of 23 HCC tissues and one of mutations was missense. Expression of KLF6 mRNA or protein was down-regulated in 8 (34.7%) or 9 (39.1%) of 23 HCC tissues. Wild-type KLF6 (wtKLF6) inhibited cellular proliferation and prolonged G1-S transition by inducing the expression of p21WAF1 following stable transfection into cultured HepG2 cells, but tumor-derived KLF6 mutant (mKLF6) had no effects. Conclusion: Our findings suggest that KLF6 may be involved in pathogenesis of HCC.

Aberrant methylation of the 3q25 tumor suppressor gene PTX3 in human esophageal squamous cell carcinoma

AIM:To identify the novel methylation-silenced gene pentraxin 3(PTX3) in esophageal squamous cell carcinoma(ESCC).METHODS:PTX3 mRNA expression was examined in six human ESCC cell lines,one human immortalized normal esophageal epithelial cell line,primary ESCC tumor tissue,and paired adjacent nontumor tissue using reverse transcription polymerase chain reaction(RTPCR).Semi-quantitative immunohistochemistry was used to examine cellular localisation and protein levels.Methylation specific PCR and bisulphite genomic sequencing were employed to investigate the methylation of the candidate gene.RESULTS:In the majority of ESCC cell lines,we found that PTX3 expression was down-regulated due to gene promoter hypermethylation,which was further confirmed by bisulphite genomic sequencing.Demethylation treatment with 5-aza-2'-deoxycytidine restored PTX3 mRNA expression in ESCC cell lines.Methylation was more common in tumor tissues(85%) than in adjacent nontumor tissues(25%)(P < 0.01).CONCLUSION:PTX3 is down-regulated through promoter hypermethylation in ESCC,and could potentially serve as a biomarker of ESCC.

Relationship between hepatitis B virus associated primary hepatocellular carcinoma and alteration of tumor suppressor gene p53

Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.