Fragile Histidine Triad Gene Research Articles

Juveniles, young adults, and infants with hepatitis B virus infection: A genomic study.

Integration of hepatitis B virus (HBV) DNA into the human genome is recognized as an oncogenic factor and a barrier to hepatitis B cure. In the study, biopsy liver tissues were collected from adolescents and young adults with acute HBV infection younger than or equal to 35 years of age and from HBV-infected infant patients younger than or equal to 6 months of age. A high-throughput sequencing method was used to detect HBV DNA integration. Totally, 12 adolescents, young adults, and 6 infants were included. Among the 12 patients with acute HBV infection, immunohistochemical staining of intrahepatic hepatitis B surface antigen for all displayed negative results, and no HBV DNA integrants in the hepatocyte DNA were confirmed. All infant patients had elevated levels of alanine aminotransferase and high levels of serum HBV DNA. Numerous gene sites of hepatocyte DNA were integrated by HBV DNA for each infant patient, ranging from 120 to 430 integration sites. The fragile histidine triad gene was the high-frequency integrated site in the intragenic region for infant patients. In conclusion, hepatocyte DNA is integrated by HBV DNA in babies with active hepatitis B but seems seldom affected among adolescents and young adults with acute HBV infection. Infantile hepatitis B should be taken seriously considering abundant HBV DNA integration events.

Identification of rare nsSNPs in fragile histidine triad (FHIT) gene to explore its correlation with oral cancer: An in-silico approach

Genetic alterations in fragile histidine triad (FHIT) play a pivotal role in various cancers of head, neck, lung, kidney, gastrointestinal, and breast including oral which leads to abnormal transcripts in vivo during the development of oral cancer. Owing to the importance of FHIT gene in cell proliferation, tumor suppression and survival, the structural, functional, non-synonymous SNPs (nsSNPs), and network study was conducted to look at the potential relationship between phenotypic variations and genetic variations. In silico genomic analysis of FHIT was initiated with the identification of 18 rare variants from dbSNP database followed by PredictSNP 1.0 web server analysis for predicting the deleterious and neutral mutants. A total of 11 mutations i.e. P33T, P33A, V97F, S22A, T19I, T61M, D57N, P101A, P101S, S81P and R46H corresponding to 9 nsSNPs were found to be deleterious which affects the protein. The interacting genes with FHIT were found by analyzing protein–protein interactions network using a STRING database. Gene ontology and Disease Association functional analysis of FHIT was obtained by WebGestalt. The mutational positions and amino acid variations have been mapped onto native FHIT. Structural and docking analysis of native and mutant FHIT with ER 27319 Maleate was performed using Auto Dock 4.2, GLIDE, SRide server, structural visualizers, and MD simulations to check their binding energies, stabilizing residues, and to investigate their dynamic behavior, mode of binding action and inhibitor specificity. Our in-silico analysis suggested that screening of P101S (rs533270218), S81P (rs536941406) and D57N (rs375883257) variants of FHIT could be useful for molecular diagnosis and development of vital molecular inhibitors of FHIT pathways. The diagnostic and prognostic approach of these molecular biomarkers can intrude on the predisposition to oral cancer.

Potential Role of the Fragile Histidine Triad in Cancer Evo-Dev.

Cancer development follows an evolutionary pattern of "mutation-selection-adaptation" detailed by Cancer Evolution and Development (Cancer Evo-Dev), a theory that represents a process of accumulating somatic mutations due to the imbalance between the mutation-promoting force and the mutation-repairing force and retro-differentiation of the mutant cells to cancer initiation cells in a chronic inflammatory microenvironment. The fragile histidine triad (FHIT) gene is a tumor suppressor gene whose expression is often reduced or inactivated in precancerous lesions during chronic inflammation or virus-induced replicative stress. Here, we summarize evidence regarding the mechanisms by which the FHIT is inactivated in cancer, including the loss of heterozygosity and the promoter methylation, and characterizes the role of the FHIT in bridging macroevolution and microevolution and in facilitating retro-differentiation during cancer evolution and development. It is suggested that decreased FHIT expression is involved in several critical steps of Cancer Evo-Dev. Future research needs to focus on the role and mechanisms of the FHIT in promoting the transformation of pre-cancerous lesions into cancer.

Single-cell resolved ploidy and chromosomal aberrations in nonalcoholic steatohepatitis-(NASH) induced hepatocellular carcinoma and its precursor lesions

Nonalcoholic steatohepatitis (NASH)-induced hepatocellular carcinoma (HCC) and its precursor, nonalcoholic fatty liver disease (NAFLD) are an unmet health issue due to widespread obesity. We assessed copy number changes of genes associated with hepatocarcinogenesis and oxidative pathways at a single-cell level. Eleven patients with NASH-HCC and 11 patients with NAFLD were included. Eight probes were analyzed using multiplex interphase fluorescence in situ hybridization (miFISH), single-cell imaging and phylogenetic tree modelling: Telomerase reverse transcriptase (TERT), C-Myc (MYC), hepatocyte growth factor receptor tyrosine kinase (MET), tumor protein 53 (TP53), cyclin D1 (CCND1), human epidermal growth factor receptor 2 (HER2), the fragile histidine triad gene (FHIT) and FRA16D oxidoreductase (WWOX). Each NASH-HCC tumor had up to 14 distinct clonal signal patterns indicating multiclonality, which correlated with high tumor grade. Changes frequently observed were TP53 losses, 45%; MYC gains, 36%; WWOX losses, 36%; and HER2 gains, 18%. Whole-genome duplications were frequent (82%) with aberrant tetraploid cells evolving from diploid ancestors. Non-tumorous NAFLD/NASH biopsies did not harbor clonal copy number changes. Fine mapping of NASH-HCC using single-cell multiplex FISH shows that branched tumor evolution involves genome duplication and that multiclonality increases with tumor grade. The loss of oxidoreductase WWOX and HER2 gains could be potentially associated with NASH-induced hepatocellular carcinoma.

Epigenetic changes in the promoter of the fragile histidine triad (FHIT) gene in human sebocytes under the influence of in vitro culture

Due to the lack of tumor suppressor function of the fragile histidine triad (FHIT) gene product, sebaceous gland carcinomas can develop. The model of the sebocyte cell line SZ95 was used to identify methylated CpG islands at the 5'-end of the FHIT gene and the decrease of gene expression as well as the increase of double-stranded (ds) DNA breaks were examined. Methylation, immunofluorescence analysis, promotor sequencing and treatment of SZ95 cells with 5‑azacytidine/trichostatinA (TSA). The cultivation was accompanied by an increasing methylation of the CpG islands, adecrease of the FHIT gene expression and an accumulation of ds-DNA breaks. Treatment with 5‑azacytidine/TSA showed adecrease in DNA methylation and are-expression of FHIT transcripts. Epigenetic changes in the cellular genome are caused by in vitro cell culture. Consequently, apositive selection of sebocytes with an epigenetically inactivated FHIT locus occurs.

Germinal epimutation of Fragile Histidine Triad (FHIT) gene is associated with progression to acute and chronic adult T-cell leukemia diseases

BackgroundHuman T cell Leukemia virus type 1 (HTLV-I) is etiologically linked to adult T cell leukemia/lymphoma (ATL) and an inflammatory neurodegenerative disease called HTLV-I-associated myelopathy or tropical spastic paraparesis (HAM/TSP). The exact genetic or epigenetic events and/or environmental factors that influence the development of ATL, or HAM/TSP diseases are largely unknown. The tumor suppressor gene, Fragile Histidine Triad Diadenosine Triphosphatase (FHIT), is frequently lost in cancer through epigenetic modifications and/or deletion. FHIT is a tumor suppressor acting as genome caretaker by regulating cellular DNA repair. Indeed, FHIT loss leads to replicative stress and accumulation of double DNA strand breaks. Therefore, loss of FHIT expression plays a key role in cellular transformation.MethodsHere, we studied over 400 samples from HTLV-I-infected individuals with ATL, TSP/HAM, or asymptomatic carriers (AC) for FHIT loss and expression. We examined the epigenetic status of FHIT through methylation specific PCR and bisulfite sequencing; and correlated these results to FHIT expression in patient samples.ResultsWe found that epigenetic alteration of FHIT is specifically found in chronic and acute ATL but is absent in asymptomatic HTLV-I carriers and TSP/HAM patients’ samples. Furthermore, the extent of FHIT methylation in ATL patients was quantitatively comparable in virus-infected and virus non-infected cells. We also found that longitudinal HTLV-I carriers that progressed to smoldering ATL and descendants of ATL patients harbor FHIT methylation.ConclusionsThese results suggest that germinal epigenetic mutation of FHIT represents a preexisting mark predisposing to the development of ATL diseases. These findings have important clinical implications as patients with acute ATL are rarely cured. Our study suggests an alternative strategy to the current “wait and see approach” in that early screening of HTLV-I-infected individuals for germinal epimutation of FHIT and early treatment may offer significant clinical benefits.

Effects of trichostatin A on FHIT and WWOX genes expression, cell growth inhibition and apoptosis induction in hepatocellular carcinoma WCH 17 cell line

Previously, we evaluated the effect of trichostatin A (TSA) on the expression of DNA methyltransferase 1 (DNMT1) in Hepatocellular Carcinoma (HCC). Fragile histidine triad (FHIT) and WW domain-containing oxidoreductase (WWOX) are two of the most common down-regulated genes in many cancers located on chromosome 3p14.2 and 16q23.3-24.1 respectively. The aim of the current study was to assess the effect of TSA on these genes expression, cell growth, and apoptosis in HCC WCH 17 cell. The cells were seeded and treated with TSA at different times. Then, MTT assay, flow cytometry, and qRT-PCR were achieved to determine viability, apoptosis and gene expression respectively. Cell growth was significantly inhibited, 92 to 36% after 24 h, 86 to 28% after 48 h, and 78 to 24% after 72 h. The results of flow cytometry confirmed that TSA increased apoptosis compared to the control group, the apoptosis percentage increased to 12%, 16%, and 18% in comparison to control groups (2%). Significant up-regulation of the genes was observed in all treated groups. We concluded that re-expression of silenced WWOX and FHIT genes could be achieved by TSA resulting in cell growth inhibition and apoptosis induction in WCH 17 cell.

FHIT as a biomarker for early screening of adult T-cell leukemia.

Adult T-cell leukemia (ATL) is an incurable leukemia deriving from human T-cell leukemia virus (HTLV-I) infected cells. In our most recent study, we discovered that methylation of the tumor suppressor, fragile histidine triad gene (FHIT), exists in the majority of acute and chronic ATL patients. Methylation was seen in non-tumorigenic cells, in cells with low levels of HTLV-I integrated DNA, in longitudinal samples from HTLV-I carriers, in a percentage of HTLV-I carriers, and in direct descendants of ATL patients. Overall, this suggests that FHIT methylation is likely present in patients, prior to HTLV-I infection, and predisposes HTLV-I carriers to ATL development. In this commentary we discuss the importance of developing diagnostic tools for the early detection of FHIT methylation and the possibility that prior FHIT methylation may predispose any individual to the development of cancer.

Relationship between Methylation of FHIT and CDH13 Gene Promoter Region and Liver Cancer.

In order to demonstrate the relationship between methylation of fragile histidine triad (FHIT) and T-cadherin/H-cadherin (CDH13) genes and liver cancer, the methylation status of FHIT and CDH13 was detected in healthy individuals and in Mongolian and Han patients with liver cancer. The phenol-chloroform method was used to extract genomic DNA. The methylation specific polymerase chain reaction method was applied to detect the methylation status of FHIT and CDH13. The relationship between smoking and alcohol consumption and gene (FHIT and CDH13) methylation was analyzed. There was significant difference in methylation rate of FHIT (72.67%, 34.67%) and CDH13 (72.0%, 28.0%) between liver cancer patients and healthy individuals of Mongolian descent (P<0.05), as well as that of FHIT (68%, 30.67%) and CDH13 (64%, 26%) between liver cancer patients and healthy individuals of Han individuals (P<0.05). There was also a relationship between smoking and drinking and the methylation of FHIT and CDH13 (P<0.05). Thus, the methylation of FHIT and CDH13 had a relationship with liver cancer incidence. Smoking and alcohol ingestion may promote the methylation of FHIT and CDH13.

Genome-Wide Analysis of the DNA Methylation Profile Identifies the Fragile Histidine Triad (FHIT) Gene as a New Promising Biomarker of Crohn’s Disease

Inflammatory bowel disease is known to be associated with a genetic predisposition involving multiple genes; however, there is growing evidence that abnormal interactions with environmental factors, particularly epigenetic factors, can also significantly contribute to the development of inflammatory bowel disease (IBD). Although many genome-wide association studies have been performed to identify the genetic changes underlying the pathogenesis of Crohn’s disease, the role of epigenetic alterations based on molecular complications arising from Crohn’s disease (CD) is poorly understood. We employed an unbiased approach to define DNA methylation alterations in colonoscopy samples from patients with CD using the HumanMethylation450K BeadChip platform. Technical and functional validation was performed by methylation-specific PCR (MSP) and bisulfite sequencing of a validation set of 207 patients with CD samples. Immunohistochemistry (IHC) analysis was performed in the representative sample sets. DNA methylation profile in CD revealed that 135 probes (24 hypermethylated and 111 hypomethylated probes) were differentially methylated. We validated the methylation levels of 19 genes that showed hypermethylation in patients with CD compared with normal controls. We uniquely identified that the fragile histidine triad (FHIT) gene was hypermethylated in a disease-specific manner and its protein level was downregulated in patients with CD. Pathway analysis of the hypermethylated candidates further suggested putative molecular interactions relevant to IBD pathology. Our data provide information on the biological and clinical implications of DNA hypermethylated genes in CD, identifying FHIT methylation as a promising new biomarker for CD. Further study of the role of FHIT in IBD pathogenesis may lead to the development of new therapeutic targets.

P828 DNA methylation profile defines epigenetic characteristics and molecular targets of Crohn’s disease

Abstract Background Inflammatory bowel disease(IBD) is known to be caused by a genetic predisposition involving multiple genes; however, there is growing evidence that abnormal interaction with environmental, particularly epigenetic, factors can have a significant contribution during the development of IBD. Although many studies, particularly genome-wide association studies (GWAS), have been performed to identify the genetic changes underlying the pathogenesis of Crohn’s disease (CD), the role of epigenetic changes in the development of complications arising from CD is poorly understood. Methods Here, we employed an unbiased approach to define DNA methylation alteration in CD patients using the Human Methylation 450K Bead Chip platform. Compared to normal controls, the majority of differential DNA methylation in CD patient samples was in the promoter, intergenic, and gene body regions. Results The DNA methylation profile in CD revealed 134 probes (23 hypermethylated and 111 hypomethylated probes) that were differentially methylated. We validated the methylation levels of 19 genes that showed hypermethylation in CD patients compared with normal control. Technical validation was performed using quantitative MSP analysis and we finally identified that the Fragile Histidine Triad (FHIT) genes were hypermethylated in a disease-specific manner. Using a large cohort for CD patients samples (n = 207), we found that FHIT is frequently methylated in CD patients (71%) by MSP and significantly increasing methylation level in CD patient samples. In addition, we confirmed the methylation level of FHIT gene between normal colon and CD patients. Due to hypermethylation of FHIT gene promoter in CD patients, we observed that the level of FHIT protein is downregulated in CD patient samples compared with normal by IHC analysis. Gene network analysis by GO and metascape for hypermethylated genes in CD patients suggested putative cellular and molecular interactions relevant to IBD pathology. Conclusion Overall, our DNA methylation profile identifies newly hypermethylated genes in CD, as well as paves the way to a better understanding of the role of epigenetics in the pathogenesis of CD, and provides direction for future research in the diagnosis/prognosis or therapeutic treatments for CD.

Expression of Fhit, hWAPL and Survivin in Cervical Squamous Cell Carcinoma and Significance Thereof

Objective To preliminarily discuss the role of fragile histidine triad (FHIT) gene, human wings apart-like (hWAPL) gene, survivin gene in lymphatic metastasis of cervical squamous cell carcinoma. Method Expression of FHIT, hWAPL and survivin in 30 cases of normal squamous epithelium, 30 cases of CIN III and 60 cases of cervical squamous cell carcinoma was detected using the immunohistochemical technique. A statistical analysis was conducted for the relationship between the expression levels of FHIT, hWAPL and survivin and clinical pathologic parameters through expression count LVD of FHIT. Results FHIT value is 1.93±0.57 in the group of normal squamous epithelium, 2.87±0.63 in the group of CIN III and 4.12±0.72 in the group of cervical squamous cell carcinoma. The difference has statistical significance (P<0.05). The positive expression of hWAPL in normal cervical tissues is 0.00% (0/30), the positive expression rate is 36.67% (11/30) in the group of CIN III, and the positive expression rate is 63.33% (38/60) in the group of cervical squamous cell carcinoma. The difference has statistical significance (P<0.01). The positive expression rate of survivin in normal cervical tissues is 0.00% (0/30), the positive expression rate is 30.00% (9/30) in the group of CIN III, the expression rate is 61.67% (37/60) in the group of cervical squamous cell carcinoma. The difference has statistical significance (P<0.01). Conclusion FHIT, hWAPL and survivin promote lymphangiogenesis during occurrence and progression of cervical squamous cell carcinoma and lymphangiogenesis plays a vital role in lymphatic metastasis of cervical squamous cell carcinoma.

Evaluation of Relationship between Occurrence of Liver Cancer and Methylation of Fragile Histidine Triad (FHIT) and P16 Genes

BackgroundWe examined the level of fragile histidine triad (FHIT) and p16 gene methylation in patients with hepatocellular carcinoma and explored the relationship to liver cancer.Material/MethodsThere were 56 patients with primary liver cancer who were admitted to the hospital from July 2015 to October 2017 included in the liver cancer group, and 24 non-hepatoma patients (hepatitis A/hepatitis B/hepatitis C, liver cirrhosis, liver fibrosis, and fatty liver, alcoholic liver identified as a control group. Fasting venous blood samples were collected from the 2 groups. Methylation-specific PCR (MSP) was used to detect the methylation of FHIT and p16 genes in the 2 groups. The risk factors for lung cancer were analyzed by logistic regression. In addition, the effects of FHIT and p16 gene methylation on the diagnostic accuracy of liver cancer were calculated.ResultsThe incidence of FHIT and p16 methylation in serum from the liver cancer group was 51.8% and 67.9%, respectively. The incidence of FHIT and p16 methylation in the non-hepatoma group was 16.7% and 25.0%. There was a statistical statistically correlated with gender, and the methylation of FHIT and p16 genes (P<0.05). From logistic regression analysis results, methylation of p16 and FHIT genes was an independent risk factor for hepatocellular carcinoma with odds ratio (OR) values of 10.550 (2.313~48.116) and 8.239 (2.386~28.455), respectively.ConclusionsThe methylation of p16 and FHIT genes was an independent risk factor for hepatocellular carcinoma.

Assessment of fragile histidine triad expression in ameloblastoma, odontogenic keratocyst and dentigerous cyst.

FHIT (Fragile histidine triad) a member of tumor suppressor family, has been extensively studied in many solid tumors including head and neck squamous cell carcinoma. Among all head and neck cyst and tumors odontogenic lesions account approximately 3%-9%. The molecular pathogenesis of these lesions is less explored. Defects in cell cycle regulators and tumor suppressor genes could result in the development of odontogenic cyst and tumors. Hence, we aimed to determine the significant role of a tumor suppressor gene FHIT in most commonly occurring odontogenic lesions mainly ameloblastoma, odontogenic keratocyst and dentigerous cyst. Immunohistochemical analysis of FHIT was done in ameloblastoma, odontogenic keratocyst, dentigerous cyst and dental follicle. Interpretation of the stained slides were done using standard scoring criteria by two pathologist. The results were subjected for statistical analysis. Expression of FHIT varied among the groups, with highest negative expression in ameloblastoma 44.4% followed by odontogenic keratocyst 14% and 100%positive expression was seen in dentigerous cyst. The expression levels between the groups were statistically insignificant. The varied expression or negative expression of FHIT could be considered as an indicator for aggressive behavior and transformation of preneoplastic/cystic epithelium.

Mechanisms shaping the mutational landscape of the FRA3B/FHIT‐deficient cancer genome

Genome instability is an enabling characteristic of cancer that facilitates the acquisition of oncogenic mutations that drive tumorigenesis. Underlying much of the instability in cancer is DNA replication stress, which causes both chromosome structural changes and single base-pair mutations. Common fragile sites are some of the earliest and most frequently altered loci in tumors. Notably, the fragile locus, FRA3B, lies within the fragile histidine triad (FHIT) gene, and consequently deletions within FHIT are common in cancer. We review the evidence in support of FHIT as a DNA caretaker and discuss the mechanism by which FHIT promotes genome stability. FHIT increases thymidine kinase 1 (TK1) translation to balance the deoxyribonucleotide triphosphates (dNTPs) for efficient DNA replication. Consequently, FHIT-loss causes replication stress, DNA breaks, aneuploidy, copy-number changes (CNCs), small insertions and deletions, and point mutations. Moreover, FHIT-loss-induced replication stress and DNA breaks cooperate with APOBEC3B overexpression to catalyze DNA hypermutation in cancer, as APOBEC family enzymes prefer single-stranded DNA (ssDNA) as substrates and ssDNA is enriched at sites of both replication stress and DNA breaks. Consistent with the frequent loss of FHIT across a broad spectrum of cancer types, FHIT-deficiency is highly associated with the ubiquitous, clock-like mutation signature 5 occurring in all cancer types thus far examined. The ongoing destabilization of the genome caused by FHIT loss underlies recurrent inactivation of tumor suppressors and activation of oncogenes. Considering that more than 50% of cancers are FHIT-deficient, we propose that FRA3B/FHIT fragility shapes the mutational landscape of cancer genomes.

Effects of FHIT gene on proliferation and apoptosis of osteosarcoma cells.

Regulatory effects of fragile histidine triad (FHIT) gene on proliferation and apoptosis of osteosarcoma cells were studied. The hFOB1.19 and Saos2 cells were routinely cultured, pcDNA3.1-FHIT overexpression vectors carrying FHIT gene fragments and blank pcDNA3.1 vectors were transfected into Saos2 cells, respectively, and the cells were divided into hFOB, Saos2, transfection and no-load transfection groups. After transfection for 48 h, the cells were collected and analyzed. The expression of FHIT messenger ribonucleic acid (mRNA) was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of FHIT protein was detected by western blot analysis. Cell Counting Kit 8 (CCK8) was used to detect cell proliferation, and flow cytometry was used to detect apoptosis. The expression of FHIT mRNA was significantly decreased in Saos2 group compared with that in hFOB group, and the difference was statistically significant (P<0.05). The expression of FHIT mRNA was significantly increased in transfection group compared with that in Saos2 group, and the difference was statistically significant (P<0.05). The expression of FHIT protein was obviously decreased in Saos2 group compared with that in hFOB group, and there was a statistically significant difference (P<0.05). The expression of FHIT protein was obviously increased in transfection group compared with that in Saos2 group, and the difference was statistically significant (P<0.05). Compared with that in the hFOB group, the cell proliferation rate was remarkably increased in Saos2 group, while the apoptosis rate was remarkably decreased, showing statistically significant differences (P<0.05). Compared with those in Saos2 group, the cell proliferation rate was significantly decreased in transfection group, while the apoptosis rate was significantly increased, and the differences were statistically significant (P<0.05). In conclusion, FHIT gene regulates the proliferation and apoptosis of Saos2 osteosarcoma cells, inhibits the proliferation and promotes apoptosis of Saos2 osteosarcoma cells.

Effect of interventional embolotherapy on FHIT and p16 expression in hepatocellular carcinoma patients.

Effects of interventional embolotherapy on the expression of fragile histidine triad (FHIT) and p16 in hepatocellular carcinoma (HCC) patients were investigated. Patients with primary HCC who were definitely diagnosed and treated in the Department of Gastroenterology in Qingdao Central Hospital from March 2014 to March 2016 were selected, and they underwent interventional embolotherapy. HCC and cancer-adjacent tissues of the patients were harvested for immunohistochemical staining. The correlation between the expression levels of FHIT and p16 was analyzed at the gene and protein level. Clinical data were collected, and whether they were correlated with the expression of FHIT and p16 was investigated. The expression levels of FHIT and p16 in primary HCC tissues were remarkably lower than that in cancer-adjacent tissues (P<0.05). In HCC tissues, FHIT expression was obviously positively correlated with p16 expression (Spearman's correlation coefficient, r=0.308; P=0.025). FHIT was related to HCC tumor-node-metastasis (TNM) staging, the differentiation degree in Edmondson-Steiner grading, lymph node metastasis and portal vein thrombosis (P<0.05 in all comparisons), whereas, p16 was associated with tumor size and the differentiation degree in Edmondson-Steiner grading (P<0.05 in all comparisons). The expression of FHIT and p16 genes and proteins in HCC tissues were obviously lower than those in cancer-adjacent tissues (P<0.05 in all comparisons). FHIT and p16 genes, as tumor suppressor genes, inhibit the proliferation of HCC, and there is a positive correlation between them. The proteins of the FHIT and p16 can be used as new indicators for clinical detection, thus providing a new method for clinical diagnosis.

Characterization of a Clival Chordoma Xenograft Model Reveals Tumor Genomic Instability

Patient-derived xenografts retain the genotype of the parent tumors more readily than tumor cells maintained in culture. The two previously reported clival chordoma xenografts were derived from recurrent tumors after radiation. To study the genetics of clival chordoma in the absence of prior radiation exposure we established a patient-derived xenograft at primary resection of a clival chordoma. Epicranial grafting of clival chordoma collected during surgery was performed. Tumor growth was established in a nonobese diabetic/severe combined immunodeficiency mouse and tumors have been passaged serially for seven generations. Physaliferous cell architecture was shown in the regenerated tumors, which stained positive for Brachyury, cytokeratin, and S100 protein. The tumors showed bone invasion. Single-nucleotide polymorphism analysis of the tumor xenograft was compared with the parental tumor. Copy number gain of the T gene (brachyury) and heterozygous loss of cyclin dependent kinase inhibitor 2A (CDKN2A) was observed. Heterozygous loss of the tumor-suppressor fragile histidine triad (FHIT) gene also was observed, although protein expression was preserved. Accumulation of copy number losses and gains as well as increased growth rate was observed over three generations. The patient-derived xenograft reproduces the phenotype of clival chordoma. This model can be used in the future to study chordoma biology and to assess novel treatments.

In vivo identification of novel TGIF2LX target genes in colorectal adenocarcinoma using the cDNA-AFLP method

Background and study aimsHomeobox-containing genes are composed of a group of regulatory genes encoding transcription factors involved in the control of developmental processes. The homeodomain proteins could activate or repress the expression of downstream target genes. This study was conducted to in vivo identify the potential target gene(s) of TGIF2LX in colorectal adenocarcinoma. MethodsA human colorectal adenocarcinoma cell line, SW48, was transfected with the recombinant pEGFPN1-TGIF2LX. The cells were injected subcutaneously into the flank of the three groups of 6-week-old female athymic C56BL/6 nude mice (n = 6 per group). The transcript profiles in the developed tumours were investigated using the cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. ResultsThe real-time RT-PCR and DNA sequencing data for the identified genes indicated that the N-terminal domain-interacting receptor 1 (Nir1) gene was suppressed whereas Nir2 and fragile histidine triad (FHIT) genes were upregulated followed by the overexpression of TGIF2LX gene. ConclusionDownregulation of Nir1 and upregulation of Nir2 and FHIT genes due to the overexpression of TGIF2LX suggests that the gene plays an important role as a suppressor in colorectal adenocarcinoma.

Interaction between abnormal expression of fragile histidine triad and methyl-CpG-binding protein 2 on cervical cancerization

Objective: To explore the relationship between abnormal expression of fragile histidine triad (FHIT) gene and methyl-CpG-binding protein 2 (MeCP2) as well as their interaction on cervical cancerization. Methods: A total of 73 patients with cervical squamous cell carcinoma (SCC), 113 patients with cervical intraepithelial neoplasia (CIN Ⅰ, n=45; CINⅡ/Ⅲ, n=68) and 60 women with normal cervix (NC) were included in the study. Real time PCR and Western blot were performed to detect the expression levels of mRNA and protein about FHIT and MeCP2, respectively. The methylation status of FHIT gene CpG island was tested by methylation-specifc PCR (MSP). Kruskal-Wallis H test, χ(2) test, trend χ(2) test and Spearman correlation analysis were conducted with software SPSS 20.0. The interaction was evaluated by generalized multifactor dimensionality reduction (GMDR) model. Results: With the deterioration of cervical lesion, the methylation rates of FHIT gene CpG island (χ(2)=18.64, P<0.001; trend χ(2)=18.08, P<0.001) increased gradually, while the expression levels of FHIT mRNA (H=27.32, P<0.001; trend χ(2)=12.65, P<0.001) and protein (H=47.10, P<0.001; trend χ(2)=29.79, P<0.001) decreased gradually. There was a negative correlation between the methylation rates of FHIT gene CpG island and the expression level of FHIT protein (r=-0.226, P<0.001). The levels of MeCP2 mRNA (H=26.19, P<0.001; trend χ(2)=11.81, P=0.001) and protein (H=69.02, P<0.001; trend χ(2)=47.44, P<0.001) increased gradually with the aggravation of cervical lesions. There was a positive correlation between the expression level of MeCP2 protein and the FHIT mRNA Ct ratio (r=0.254, P<0.001). Expression of proteins were negatively correlated between MeCP2 and FHIT (r=-0.213, P=0.001). The results analyzed by GMDR model showed that there were interactions among high MeCP2 protein expression, the CpG island methylation of FHIT and mRNA and protein expression in CINⅡ/Ⅲ group, and among high MeCP2 mRNA and protein expression, the CpG island methylation of FHIT and low mRNA and protein expression in SCC group. Conclusion: High expression of MeCP2 mRNA and protein, the CpG island methylation and low mRNA and protein expression of FHIT could increase the risk of cervical carcinogenesis, and there might be a synergistic effect on cervical carcinogenesis.