Codon 249 mutations of p53 gene in development of hepatocellular carcinoma

Hepatocellular carcinoma (HCC): Epidemiology, etiology and molecular classification

Hepatocellular carcinoma (HCC), the primary malignancy of hepatocytes, is a diagnosis with bleak outcome. According to National Cancer Institute's SEER database, the average five-year survival rate of HCC patients in the US is 19.6% but can be as low as 2.5% for advanced, metastatic disease. When diagnosed at early stages, it is treatable with locoregional treatments including surgical resection, Radio-Frequency Ablation, Trans-Arterial Chemoembolization or liver transplantation. However, HCC is usually diagnosed at advanced stages when the tumor is unresectable, making these treatments ineffective. In such instances, systemic therapy with tyrosine kinase inhibitors (TKIs) becomes the only viable option, even though it benefits only 30% of patients, provides only a modest (~3months) increase in overall survival and causes drug resistance within 6months. HCC, like many other cancers, is highly heterogeneous making a one-size fits all option problematic. The selection of liver transplantation, locoregional treatment, TKIs or immune checkpoint inhibitors as a treatment strategy depends on the disease stage and underlying condition(s). Additionally, patients with similar disease phenotype can have different molecular etiology making treatment responses different. Stratification of patients at the molecular level would facilitate development of the most effective treatment option. With the increase in efficiency and affordability of "omics"-level analysis, considerable effort has been expended in classifying HCC at the molecular, metabolic and immunologic levels. This review examines the results of these efforts and the ways they can be leveraged to develop targeted treatment options for HCC.

Immunohistochemical Determination of p53 Protein Overexpression for Predicting p53 Gene Mutations in Hepatocellular Carcinoma: A Meta-Analysis

BACKGROUND

Whether increased expression of the tumor suppressor protein p53 indicates a p53 gene mutation in hepatocellular carcinoma (HCC) remains unclear. We conducted a meta-analysis to determine whether p53 protein overexpression detected by immunohistochemistry (IHC) offers a diagnostic prediction for p53 gene mutations in HCC patients.

METHODS

Systematic literature searches were conducted with an end date of December 2015. A meta-analysis was performed to estimate the diagnostic accuracy of IHC-determined p53 protein overexpression in the prediction of p53 gene mutations in HCC. Sensitivity, subgroup, and publication bias analyses were also conducted.

RESULTS

Thirty-six studies were included in the meta-analysis. The results showed that the overall sensitivity and specificity for IHC-determined p53 overexpression in the diagnostic prediction of p53 mutations in HCC were 0.83 (95% CI: 0.80-0.86) and 0.74 (95% CI: 0.71-0.76), respectively. The summary positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 2.65 (95% CI: 2.21-3.18) and 0.36 (95% CI: 0.26-0.50), respectively. The diagnostic odds ratio (DOR) of IHC-determined p53 overexpression in predicting p53 mutations ranged from 0.56 to 105.00 (pooled, 9.77; 95% CI: 6.35-15.02), with significant heterogeneity between the included studies (I2 = 40.7%, P = 0.0067). Moreover, subgroup and sensitivity analyses did not alter the results of the meta-analysis. However, potential publication bias was present in the current meta-analysis.

CONCLUSION

The upregulation of the tumor suppressor protein p53 was indeed linked to p53 gene mutations. IHC determination of p53 overexpression can predict p53 gene mutations in HCC patients.

Detection of TP53 R249 Mutation in Iranian Patients with Pancreatic Cancer

The TP53 gene encodes tumor protein p53 which play a major role in the etiology of pancreatic cancer. The important role of codon 249 of TP53 for binding of p53 to its sequence-specific consensus site in DNA has been revealed by crystallography's studies, and mutation at this codon was detected in the plasma of some human cancers. The TP53 Mut assessor software within the International Agency for Research on Cancer (IARC) TP53 Database was performed to evaluate every possible mutation at codon 249. DNA was extracted from the plasma of 133 pancreatic cancer patients and 85 noncancer-bearing individuals. Exon 7 in TP53 was amplified, and mutation at R249 was identified by the endonuclease cleavage of HaeIII. The group of patients showed a frequency of 11% (22 of 133 samples) R249 mutation compared to 3.5% (3 of 85 samples) in the group of control which was significant (P = 0.03). This mutation demonstrated statistically significant association with pancreatic cancer risk in unadjusted odds ratio (OR: 3.74, 95% CI: 1.1–13.2; P = 0.041); however when adjusted for confounding factors, it was marginally significant because of lower control samples. These findings demonstrate that mutation at R249 of TP53 can be considered for increasing risk of pancreatic cancer that needs more research.

Hepatocellular carcinoma and liver cirrhosis TP53 mutation analysis reflects a moderate dietary exposure to aflatoxins in Espírito Santo State, Brazil

The close relationship between aflatoxins and 249ser TP53 gene mutation (AGG to AGT, Arg to Ser) in hepatocellular carcinoma (HCC) makes this mutation an indirect indicator of dietary contamination with this toxin. We have examined the prevalence of codon 249 TP53 mutation in 41 HCC and 74 liver cirrhosis (without HCC) cases diagnosed at the HUCAM University Hospital in Vitoria, Espírito Santo State, Brazil. DNA was extracted from paraffin sections and from plasma. The mutation was detected by DNA amplification, followed by restriction endonuclease digestion and confirmed by direct sequencing. DNA restriction showed 249ser mutation in 16 HCC and 13 liver cirrhosis, but sequencing confirmed mutations in only 6 HCC and 1 liver cirrhosis. In addition, sequencing revealed 4 patients with mutations at codon 250 (250ser and 250leu) in HCC cases. The prevalence of TP53 mutation was 10/41 (24.3%) in HCC and 1/74 (1.4%) in liver cirrhosis. No relationship between the presence of mutations and the etiology of HCC was observed. TP53 exon 7 mutations, which are related to aflatoxins exposure, were found at 14.6% (249ser), 7.3% (250leu) and 2.4% (250ser) in 41 cases of HCC and 1.4% in 74 liver cirrhosis (without HCC) cases, suggesting a moderate dietary exposure to aflatoxins in the Espírito Santo State, Brazil.

Study of p53 codon 72 polymorphism and codon 249 mutations in Southern India in relation to age, alcohol drinking and smoking habits

Germline polymorphisms of genes involved in different steps of tumorigenesis like p53, the tumor suppressor gene, are reported to determine the individual susceptibility to cancer. Lung cancer is one of the most common and lethal cancers and tobacco smoking remains its most important etiologic factors. The most frequently p53 mutated codons of lung cancer are 72 (exon 4) and 249 (exon 7). Since mutations in the p53 gene are present in ∼40% of all human lung cancers and are more common in smokers than in nonsmokers, we aimed to detect the status of p53 at codon 72 for Arg/Arg or Arg/Pro or Pro/Pro allele polymorphism and p53 codon 249 mutation in smokers and nonsmokers of South India. Allele frequencies in the nonsmokers were 0.16 for the Arg/Pro allele and 0.84 for the Pro/Pro allele in our study population. Among the smokers, the frequencies of the Arg/Pro, Arg/Arg, and Pro/Pro alleles were 0.88, 0.04, and 0.08, respectively. No mutation was detected in both smokers and nonsmokers in p53 codon 249. From the worldwide scenario, it can be speculated that the smokers, with Arg/Pro genotype are more prone for lung cancer or to other types of cancer.

The R246S hot-spot p53 mutant exerts dominant-negative effects in embryonic stem cells in vitro and in vivo

p53 is the most frequently mutated tumour-suppressor gene in human cancers. Mutant p53 is thought to contribute to carcinogenesis by the acquisition of gain-of-function properties or through the exertion of dominant-negative (DN) effects over the remaining wild-type protein. However, the context in which the DN effects are observed is not well understood. We have therefore generated `knock-in' mouse embryonic stem (ES) cells to investigate the effects of expressing a commonly found hot-spot p53 mutant, R246S – the mouse equivalent of human R249S, which is associated with hepatocellular carcinomas. We demonstrate here that R246S mutant p53 exhibits DN effects with respect to target gene expression, cell survival and cell cycle arrest both in cells that are in the undifferentiated state and upon differentiation. The knock-in cells contain higher levels of p53 that localizes to the nucleus even in the absence of genotoxic stress and yet remains non-functional, reminiscent of mutant p53 found in human tumours. In a model based on carbon-tetrachloride-induced liver injury, these cells were consistently highly tumorigenic in vivo, similar to p53–/– cells and in contrast to both p53+/+ and p53+/– ES cells. These data therefore indicate that the DN effects of mutant p53 are evident in the stem-cell context, in which its expression is relatively high compared with terminally differentiated cells.

Somatic mutation analysis of p53 and ST7 tumor suppressor genes in gastric carcinoma by DHPLC

AIM: To verify the effectiveness of denaturing high-performance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues. The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.

METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.

RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40%) than that in diffuse-type (8.33%) carcinomas of the stomach. No mutation of ST7 gene was found.

CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.

Differentiation of hepatocellular carcinoma SMMC-7721 cell line induced by Chinese medicine recipe Weichangan

AIM

To observe the differentiation in hepatocellular carcinoma cell line induced by Chinese medicine recipe Weichangan.

METHODS

Weichangan, contrasted by the retinoic acid and distilled water, was made by using serum pharmacological method. The inhibition on the growth of SMMC-7721 cell line by Weichangan was observed through the method of MTT and Alamar Blue. Radioimmunoassay was applied to determine the concentration of a-fetoprotein and albumin secreted by the incubated cells. Western blot method was used to detect the mutant p53, p16 and p21 protein expression in SMMC-7721 cell line.

RESULTS

MTT assay showed both Weichangan and serum retinoic acid had inhibiting effect on the proliferation of human hepatocellular carcinoma SMMC-7721 cell line. Weichangan reached its maximal inhibition effect after 48 hours, while the effect of retinoic acid decreased gradually after 48 hours. Alamar Blue method showed that significant decrease was found in serum Weihangan after 16 hours compared with that in the control. After 32 hours, the decrease induced by Alamar Blue was more significant than that in cells incubated with serum Weichangan compared with those incubated in serum retinoic acid, indicating the gradual and durable action of Weichangan recipe. The decreased amount (11.4±1.4 mg/L vs 17.2±1.1 mg/L, P =0.036) of a-fetoprotein and increased amount (0.40±0.02 mg/L vs 0.29±0.01 mg/L, P =0.043) of albumin were found in the cells incubated in serum Weichangan. Western blot method showed decreased expression of p53 protein and increased expression of p16 and p21 protein in cells incubated in serum Weichangan.

CONCLUSION

The results suggest that Weichangan inhibits the growth of SMMC-7721 cell line and induces the differentiation in this hepatocellular carcinoma cell line. The effect on p53, p16 and p21 may be the mechanisms of Weichangan in inducing the differentiation of this cell lines.

Novel assay of competitively differentiated polymerase chain reaction for screening point mutation of hepatitis B virus

AIM: Point mutation, one of the commonest gene mutations, is the most important molecular pathogenesis of cancer and chronic infection. The commonest methods for detection of point mutation are based on polymerase chain reaction (PCR). These techniques, however, cannot be used in large scale screening since they are neither accurate nor simple. For this reason, this study established a novel method of competitively differentiated PCR (CD-PCR) for screening point mutation in clinical practice.

METHODS: Two competitively differentiated primers for mutant-type and wild-type templates respectively with an identically complemented region in 3’ end except for last 2 base pairs and a different non-complemented region in 5’ end were designed. Thus, competitive amplification might be carried out at a lower annealing temperature at first, and then differentiated amplification at a higher annealing temperature when primers could not combine with initial templates. The amplification was performed in one-tube. The products of CD-PCR were detected using microplate hybridization assay. CD-PCR was evaluated by detecting G1896A variant of hepatitis B virus (HBV) in form of recombinant plasmids and in sera from patients with hepatitis B, and compared with allele-specific PCR (AS-PCR) and competitive AS-PCR.

RESULTS: CD-PCR was successfully established. It could clearly distinguish wild-type and mutant-type plasmid DNA of G1896A variant when the amount of plasmid DNA was between 10²-10⁸copies/reaction, while for AS-PCR and competitive AS-PCR, the DNA amount was between 10²-10⁴copies/reaction. CD-PCR could detect one copy of G1896A variant among 10-100 copies of wild-type plasmid DNA. The specificity of CD-PCR was higher than those of AS-PCR and competitive AS-PCR in the detection of HBV G1896A variant in sera from patients with hepatitis B. CD-PCR was independent of the amount of HBV DNA in serum. HBV G1896A variant was more often found in HBeAg (-) patients with a lower level of detectable viremia than that with a higher level of detectable viremia (P = 0.0192).

CONCLUSION: CD-PCR is more specific since it is less influenced by the amount of initial templates and the cross amplification between mutant- and wild-type amplified products. It is also simple and time-saving. Thus, CD-PCR might be useful in routine gene typing and point mutation screening. HBV G1896A or other more important mutations have to be routinely detected in patients with a detectable level of viremia after HBeAg/antibody conversion in clinical practice.

Biological characteristics of HCC by ultrasound-guided aspiration biopsy and its clinical application

AIM: To probe the pathological biological characteristics of hepatocellular carcinoma (HCC) by the ultrasound-guided aspiration biopsy and assess the clinical application value of this method.

METHODS: The biopsy and DNA analysis by flow cytometry (FCM) were taken in 46 cases with HCC nodules, including 26 cases and 20 cases with nodules ≤ 3 cm and > 3 cm in diameters respectively, and 12 cases with intrahepatic benign hyperplastic nodules. They were taken in 22 cases of 46 cases with HCC before and after the therapy. Fine-needles and automatic histological incised biopsy needles were used. The fresh biopsy tissue was produced into the single cell suspension, which was sent for DNA detection and ratio analysis of cell period. The ratio of each DNA period of cell proliferation of each group was calculated and compared with each other. The DNA aneuploid (AN) and apoptosis cell peak were observed and their percentages were calculated.

RESULTS: The ratios of S and G₂/M periods of DNA, which reflect cell hyperproliferation, in the group with HCC tumors > 3 cm in diameter were markedly higher than those of the group with HCC nodules ≤ 3 cm in diameter and the group with the benign hyperplastic nodules (P < 0.01 except A:B of S period, P < 0.05). The ratios of the middle group were also apparently higher than those of the latter group (P < 0.01). The ratio of DNA AN of 46 cases with HCC nodules was 34.8% (16/46). None of the cases with the intrahepatic hyperplastic nodules appeared AN. The DNA AN appeared more apparently with the growth of the tumors. The AN ratio of the group with tumors > 3 cm in diameter was 55% (11/20), markedly higher than that of the group with tumors ≤ 3 cm in diameter which was 19.2% (5/26) (P < 0.01). The FCM DNA analysis of 22 specimens of hepatic carcinoma tissue before therapy showed that the aneuploid peaks appeared in 5 cases (22.7%). The ratio of G₁ period rose after therapy while the S period and G₂/M ratios fell (P < 0.01). The aneuploid peak disappeared in the 5 cases after the therapy, while the apoptosis peaks in 12 cases (54.5%) appeared.

CONCLUSION: Addition to supply the information of the pathological morphology of the tumor, the ultrasound-guided fine-needle aspiration tissue could be sent for FCM DNA analysis to comprehend its pathological biological characteristics. This can not only provide the clinic the reliable information about the occurrence, development, diagnosis, curative effect and prognosis of tumors but also supply biological information for clinic to choose therapeutic schemes.

Synergetic anticancer effect of combined quercetin and recombinant adenoviral vector expressing human wild-type p53, GM-CSF and B7-1 genes on hepatocellular carcinoma cells in vitro

AIM: This study investigated the anti-cancer effect of combined quercetin and a recombinant adenovirus vector expressing the human p53, GM-CSF and B7-1 genes (designated BB-102) on human hepatocellular carcinoma (HCC) cell lines in vitro.

METHODS: The sensitivity of HCC cells to anticancer agents was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The viability of cells infected with BB-102 was determined by trypan blue exclusion. The expression levels of human wild-type p53, GM-CSF and B7-1 genes were determined by Western blot, enzyme-linked immunosorbent assay (ELISA) and flow cytometric analysis, respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyl transferase (TdT) assay or DNA ladder electrophoresis.

RESULTS: Quercetin was found to suppress proliferation of human HCC cell lines BEL-7402, HuH-7 and HLE, with peak suppression at 50 μmol/L quercetin. BB-102 infection was also found to significantly suppress proliferation of HCC cell lines. The apoptosis of BB-102-infected HCC cells was greater in HLE and HuH-7 cells than in BEL-7402 cells. Quercetin did not affect the expression of the three exogenous genes in BB-102-infected HCC cells (P > 0.05), but it was found to further decrease proliferation and promote apoptosis of BB-102-infected HCC cells.

CONCLUSION: BB-102 and quercetin synergetically suppress HCC cell proliferation and induce HCC cell apoptosis, suggesting a possible use as a combined anti-cancer agent.

p73β inhibits transcriptional activities of enhancer I and X promoter in hepatitis B virus more efficiently than p73α

AIM: p73, as a novel member of a family of p53-related transcription factors, shares redundant functions with p53, such as the abilities of inducing apoptosis and suppressing growth. It is well known that p53 can repress HBV expression and transcription efficiently. The aim of this paper is to investigate the transcriptional effect of p73α and p73β on hepatitis B virus (HBV) and to understand the correlation between HBV and p73.

METHODS: To construct an x-gene inactivated HBV plasmid which was cotransfected with p73α or p73β expression vectors into HepG2 cells. After transiently transfection, HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) were detected by ELISA. Viral transcripts synthesized by HBV were evaluated by Northern blotting analysis. The activities of HBV regulatory elements, including enhancer I/X promoter (ENI/Xp) and enhancer II/core promoter (ENII/Cp) were monitored by luciferase assays.

RESULTS: Both p73α and p73β could repress HBsAg and HBeAg expression by downregulating the ENI/Xp and ENII/ Cp activities. But p73β exerted stronger inhibition on the activity of ENI/Xp than p73α, resulting in much lower level of viral transcripts and the antigens expression.

CONCLUSION: p73β as a novel member of p53 family can efficiently inhibit HBV transcription mainly through downregulating the activities of the HBV ENI/Xp regulatory elements.

Rapid screening mitochondrial DNA mutation by using denaturing high-performance liquid chromatography

AIM: To optimize conditions of DHPLC and analyze the effectiveness of various DNA polymerases on DHPLC resolution, and evaluate the sensitivity of DHPLC in the mutation screening of mitochondrial DNA (mtDNA).

METHODS: Two fragments of 16s gene of mitochondrial DNA (one of them F2 is a mutant fragment) and an A3243G mutated fragment were used to analyze the UV detection limit and determine the minimum percentage of mutant PCR products for DHPLC and evaluate effects of DNA polymerases on resolution of DHPLC. Under the optimal conditions, we analyzed the mtDNA mutations from muscle tissues of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) and screened blindly for variances in D-loop region of mtDNA from human gastric tumor specimen.

RESULTS: Ten A3243G variants were detected in 12 cases of MELAS, no alterations were detected in controls and these results were consistent with the results obtained by analysis of RFLP with Apa I. We also identified 26 D-loop variances in 46 cases of human gastric cancer tissues and 38 alterations in 13 gastric cancer cell lines. The mutation of mtDNA at 80 ng PCR products containing a minimum of 5% mutant sequences could be detected by using DHPLC with UV detector. Moreover, Ampli-Taq Gold polymerase was equally as good as the proofreading DNA polymerase (e.g., Pfu) in eliminating the false positive produced by Taq DNA polymerases.

CONCLUSION: DHPLC is a powerful, rapid and sensitive mutation screening method for mtDNA. Proofreading DNA polymerase is more suitable for DHPLC analysis than Taq polymerase.

Transcription factor EGR-1 inhibits growth of hepatocellular carcinoma and esophageal carcinoma cell lines

AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activity in some neoplasms, such as fibrosarcoma, breast carcinoma. This experiment was designed to investigate the role of egr-1 in the cancerous process of hepatocellular carcinoma (HCC) and esophageal carcinoma (EC), and then to appraise the effects of EGR-1 on the growth of these tumor cells.

METHODS: Firstly, the transcription and expression of egr-1 in HCC and EC, paracancerous tissues and their normal counterpart parts were detected by in situ hybridization and immunohistochemistry, with normal human breast and mouse brain tissues as positive controls. Egr-1 gene was then transfected into HCC (HHCC, SMMC7721) and EC (ECa109) cell lines in which no egr-1 transcription and expression were present. The cell growth speed, FCM cell cycle, plate clone formation and tumorigenicity in nude mice were observed and the controls were the cell lines transfected with vector only.

RESULTS: Little or no egr-1 transcription and expression were detected in HCC, EC and normal liver tissues. The expression of egr-1 were found higher in hepatocellular paracancerous tissue (transcription level P = 0.000; expression level P = 0.143, probably because fewer in number of cases) and dysplastic tissue of esophageal cancer (transcription level P = 0.000; expression level P = 0.001). The growth rate of egr-1 -transfected HHCC (HCC cell line) cells and ECa109 (EC cell line) cells was much slower than that of the controls. The proportion of S phase cell, clone formation and tumorigenicity were significantly lower than these of the controls' (decreased 45.5% in HHCC cells and 34.1% in ECa109 cells; 46.6% and 41.8%; 80.4% and 72.6% respectively). There were no obvious differences between SMMC7721 (HCC) egr-1-transfected cells and the controls with regard to the above items.

CONCLUSION: The decreased expression of egr-1 might play a role in the dysregulation of normal growth in the cancerous process of HCC and EC. egr-1 gene of transfected HHCC and ECa109 cells showed obvious suppression of the cell growth and malignant phenotypes, but no suppression in SMMC7721 (HCC cell line) cells.

Relationship between genotype and phenotype of flagellin C in Salmonella

AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains.

METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolates, then the corresponding flagellin C fragment was amplified by polymerase chain reaction, and the amplification products were analyzed by agarose gel electrophoresis.

RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar serotype H-1-d including S. muenchen, typhi and typhimurium, but not in S. paratyphoid C or S. enteritidis strains.

CONCLUSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid, sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d.

TECA hybrid artificial liver support system in treatment of acute liver failure

AIM: To assess the efficacy and safety of TECA type hybr id artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liv er failure (ALF).

METHODS: The porcine liver cells (1-2) × 10¹⁰ were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 °C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients’ blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before, during and after the treatment.

RESULTS: The average of porcine liver cells was (1.0-3.0) × 10¹⁰ obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH₃, ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment. One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K⁺, Na⁺ and Cl^-) were stable without thrombosis and bleeding in all the six patients.

CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Expression of nuclear factor-kappa B in hepatocellular carcinoma and its relation with the X protein of hepatitis B virus

AIM

In this study we investigated the relationship of the X protein of HBV and nuclear factor-kappa B (NF-kappa B) and the expression of NF-kappa B in human hepatocellular carcinoma tissues.

METHODS

Immunohistochemistry SP method was used to detect the expression of NF-kappa B and the X protein of HBV in human hepatocellular carcinoma tissues of 52 cases. Gene transfection mediated by lipofectamine was used to transfect the eukaryotic expression vector pCDNA3.1-HBX of HBV x gene into human hepatocellular carcinoma cell line HCC-9204 and NF-kappa B was detected.

RESULTS

NF kappa B was widely expressed in human hepatocellular carcinoma tissues in a total of 52 cases and its expression was related to the X protein of HBV. NF-kappa B was localized both in the cytoplasm and the nuclei of hepatocellular carcinoma cells in 11 cases which were positive for the X protein of HBV while in 41 cases negative for the X protein of HBV, NF-kappa B was only localized in the cytoplasm of hepatocellular carcinoma cells but translocated to the nuclei of hepatocellular carcinoma cells after the eukaryotic expression vector pCDNA3.1-HBX was transfected into HCC-9204 cells.

CONCLUSION

This study strongly suggests that the nuclear factor NF-kappa B is widely expressed in hepatocellular carcinoma tissues in different styles according to the expression of the X protein of HBV. NF-kappa B is abnormally activated in hepatocellular carcinoma, which is probably related to the X protein of HBV. The X protein of HBV can activate NF-kappa B to translocate into nuclei of hepatocellular carcinoma cells.

Overexpression of p27(KIP1) induced cell cycle arrest in G(1) phase and subsequent apoptosis in HCC-9204 cell line

AIM:We have previously reported that inducible over-expression of Bak may prolong cell cycle in G(1) phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27(KIP1) plays an important role in this process.METHODS:In order to elucidate the exact function of p27(KIP1) in this process, a zinc inducible p27(KIP1) stable transfectant and transient p27(KIP1)-GFP fusion transfectant were constructed. The effects of inducible p27(KIP1) on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells.RESULTS:This p27(KIP1)-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27(KIP1) induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72h of p27(KIP1) expression. p27(KIP1) caused cell cycle arrest after 24 h of induction, with 40% increase in G(1) population. Prolonged p27(KIP1) expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27(KIP1) expression showed a characteristic DNA ladder on agarose gel electrophoresis.CONCLUSION:Bak may induce cell cycle arrest in G(1) phase through upregulating expression of p27(KIP1) and subsequently lead to apoptosis in HCC-9204 cells. The p27(KIP1) -GFP fusion protein can be transiently expre-ssed in HCC-9204 cells. The inducible p27(KIP1)-expressing cell line provides a model to assess p27(KIP1) function.