Gene expression profiles of two intraspecific Larix lines and their reciprocal hybrids.

Heterosis has been widely explored in Larix breeding for more than a century, but the molecular mechanisms underlying this phenomenon remain elusive. In the present study, the genome-wide transcript profiles from two Larix genotypes and their reciprocal hybrids were analyzed using Arabidopsis 70-mer oligonucleotide microarrays. Despite sharing the same two parental lines, one of the hybrids showed obvious heterosis, while the other did not. In total, 1,171 genes were differentially expressed between the heterotic hybrid and its parents, of which 133 genes were nonadditive expression. The number of differentially expressed genes between the non-heterotic hybrid and the parents was 939, but only 54 of these genes were nonadditive expression. Further, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses indicated that most of these differentially expressed genes in the heterotic hybrid were associated with several important biological functions such as physiological processes, responses to stimulus, and starch and sucrose metabolism. The reliability of the microarray data was further validated by the Real-time quantitative RT-PCR. A high Pearson linear correlation coefficient value was detected (r = 0.759, P < 0.01). In conclusion, the gene expression profile in the Larix heterotic hybrid was significantly different from that obtained from the non-heterotic hybrid, and more nonadditive differentially expressed genes were detected in the heterotic hybrid, implying that nonadditive effects may be closely associated with the formation of heterosis in the intraspecific Larix hybridization.

DNA Methylation in Genomes of Several Annual Herbaceous and Woody Perennial Plants of Varying Ploidy as Detected by MSAP.

Polyploidization is known to accompany altered DNA methylation in higher plants, which plays an important role in gene expression regulation and maintaining genome stability. While the characteristics of DNA methylation in different polyploid plants are still to be elucidated; here, status of genomic DNA methylation in a series of diploid, triploid, and tetraploid annual herbaceous plants (watermelon and Salvia) and woody perennials (pear, Poplar, and loquat) were explored by methylation-specific amplified polymorphism analysis. The results indicated that levels of DNA methylation in triploid watermelon and Salvia were lower than their diploid parents. In triploid Poplar and pear, higher levels of DNA methylation were detected, and no significant difference was observed between triploid and tetraploid in all tested materials. Further data analysis suggested that about half of the total detected sites underwent changes of DNA methylation patterns in triploid watermelons and Salvia, as well as an obvious trend towards demethylation. However, the changes of DNA methylation patterns in three triploid woody perennials were only 17.54-33.40%. This implied that the characteristics of DNA methylation are significantly different during the polyploidization of different plant species. Furthermore, the results suggested that the level of DNA methylation was nonlinearly related to the ploidy level, and triploid plants displayed more interesting DNA methylation status. The characteristics and possible functions of DNA methylation in different ploidy series are further discussed.

CD1d gene is a target for a novel amplicon at 1q22-23.1 in human hepatocellular carcinoma.

Genome copy number variation (CNV) is one of the mechanisms to regulate the expression level of genes which contributes to the development and progression of cancer. In order to investigate the regions of high-level amplification and potential target genes within these amplicons in hepatocellular carcinoma (HCC), we analyzed HCC cell line (TJ3ZX-01) for CNV regions at the whole genome level using GeneChip Human Mapping 500K array, and also examined the relative copy number and expression levels of the related genes at candidate amplicons in 41 HCC tissues via real-time fluorescence quantitative PCR methods. Through analysis of sequence tag site(STS) markers by quantitative PCR, The two candidate amplicons at 1q found by SNP array were shown to occur in56.1% (23/41) HCC samples at 1q21 and 80.5% (33/41) at 1q22-23.1. Wilcoxon signed rank test showed expression of CD1d, which located at amplicon of 1q22-23.1 increased significantly within tumor tissues compared with paired nontumor tissues. Our study provides evidences that a novel, high-level amplicon at 1q22-23.1 occurs in both HCC cell line and tissues. CD1d is a potential target for this amplicon in HCC. The up-regulation of CD1d may be used as a novel molecular signature for diagnosis and prognosis of HCC.

Parasternal Intercostal Block Complementation Contributes to Postoperative Pain Relief in Modified Radical Mastectomy Employing Pectoral Nerve Block I and Serratus-Intercostal Block: A Randomized Trial.

PURPOSE: Pectoral nerve block I (PECS I) and serratus-intercostal plane block (SIPB) can anesthetize the majority mammary region, while parasternal intercostal block (PSI) targets the internal area during breast resection surgery. The aim of this study was to determine whether including PSI with PECS I and SIPB is more effective compared to PECS I and SIPB alone. PATIENTS AND METHODS: Sixty-two adult females undergoing unilateral modified radical mastectomy (MRM) were randomly assigned to receive either PECS I and SIPB (PS group, n=31) or a combination of PECS I, SIPB, and PSI (PSP group, n=31). The outcomes were measured with a numerical rating scale (NRS) score, and in terms of opioid consumption and anesthesia-related complications within 48 h after surgery. RESULTS: Although there were no differences in the NRS scores between the two groups during the inactive periods, the combination of three nerve blocks significantly reduced the NRS scores during movement. In addition, morphine equivalent consumption was lower in the PSP group compared to the PS group. Postoperative adverse events were similar in both groups in terms of regional anesthesia-related complications. CONCLUSION: The combination of PECS I block, SIPB, and PSI block provides superior pain relief and postoperative recovery for patients undergoing MRM.

[Identification of the regions of copy number amplification associated with hepatocellular carcinoma].

OBJECTIVE: To screen and determine the regions of copy number variation (CNV) associated with hepatocellular carcinoma (HCC) using SNP array and fluorescence quantitative PCR. METHODS: The CNV from HCC cell line TJ3ZX-01 was analyzed using GeneChip Human Mapping 500K SNP array. According to the data obtained by SNP array analysis, four candidate amplification regions were verified in 41 primary HCC samples by fluorescence quantitative PCR. RESULTS: Four regions of copy number amplification at 1q21.2, 1q22 approximately 23.1, 7p22.1 and 22q13.1 were detected by SNP array analysis. The four candidate amplicons occurred in 56.1% (23/41) of HCC samples at 1q21.2; 80.5% (33/41) at 1q22 approximately 23.1; 75.6% (31/41) at 7p22.1 and 31.7% (13/41) at 22q13.1 analyzed with sequence tagged site (STS) markers by quantitative PCR. CONCLUSION: In four candidate amplification regions selected by SNP array analysis and detected by fluorescence quantitative PCR, three amplification regions show increased copy number in more than 50.0% HCC tissues. This result indicates that these amplification regions are associated with pathogenesis of hepatocellular carcinoma.

Characters of DNA constitution in the rye B chromosome.

We have used chromosome microdissection and microcloning to construct a DNA library of the entire B chromosome (B) of rye. New rye B-specific sequences have been screened from this pool, blasted with other sequences and analyzed to elucidate the characters of DNA constitution and the possible pathway of the origin of the rye B chromosome. We report the discovery of a new sequence that is specific to the rye B centromere.

[Construction of genetic linkage map and localization of NBS-LRR like resistance gene analogues in cauliflower (Brassica oleracea var. botrytis)].

Nucleotide binding site (NBS) profiling, a new method was used to map resistance gene analogues (RGAs) in cauliflower (Brassica oleracea var. botrytis). This method allows amplification and the mapping of genetic markers anchored in the conserved NBS encoding domain of plant disease resistance genes. AFLP was also performed to construct the cauliflower intervarietal genetic map. The aim of constructing genetic map was to identify potential molecular markers linked to important agronomic traits that would be particularly useful for development and improving the species. Using 17 AFLP primer combinations and two degeneration primer/enzyme combinations, a total of 234 AFLP markers and 21 NBS markers were mapped in the F2 population derived from self-pollinating a single F1 plant of the cross AD White Flower x C-8. The markers were mapped in 9 of major linkage groups spanning 668.4 cM, with an average distance of 2.9 cM between adjacent mapped markers. The AFLP markers were well distributed throughout the linkage groups. The linkage groups contained from 12 to 47 loci each and the distance between two consecutive loci ranged from 0 to 14.9 cM. NBS markers were mapped on 8 of the 9 linkage groups of the genetic map. Most of these markers were organized in clusters. This result demonstrates the feasibility of the NBS-profiling method for generating NBS markers for resistance loci in cauliflower. The clustering of the markers mapped in this study adds to the evidence that most of them could be real RGAs.

Interleukin-10 promoter polymorphisms in patients with hepatitis B virus infection or hepatocellular carcinoma in Chinese Han ethnic population.

BACKGROUND: Since single nucleotide polymorphisms (SNPs) can serve as gene markers, polymorphism profiles may help scientists to identify the full collection of genes that contribute to the development of complex diseases such as cancer. The distribution of interleukin-10 (IL-10) promoter polymorphisms in Chinese Han ethnic patients with hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) was investigated in this study. METHODS: The polymorphisms of IL-10 promoter region were detected by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing. Sixty-six health controls, 42 patients with HBV infection, 30 HCC patients, and cell line SMMC-7721 were examined this way. RESULTS: Polymorphisms of T/C or T/N on -872 site occurred frequently in Han ethnic population. Polymorphisms were detected in HBV and HCC patients and cell line SMMC-7721. The hotspot among the polymorphisms was inserting base A between -1058 and -1057. CONCLUSION: Polymorphisms of IL-10 promoter in HBV and HCC patients may be associated with HBV infection and HCC development.

[Methylation status of FHIT gene in plasma and expression of FHIT gene in cancer tissue of cervical cancer patients].

OBJECTIVE: To explore the methylation status of 5' CpG island of fragile histidine triad (FHIT) gene in plasma and the expression of FHIT protein in cancer tissue of cervical cancer patients. METHODS: Methylation-specific PCR (MS-PCR) was employed to examine methylation of FHIT gene in 151 plasma samples before treatment. The immunohistochemistry was used to the expression of FHIT protein in cancer tissues. RESULTS: CpG island methylation of FHIT was detected in 31.13% of plasma samples. The expression of FHIT protein was decreased or discarded in 59.60% of cervical cancer tissues. Among them 47.78% was included in methylation positive samples. CONCLUSION: CpG island methylation of FHIT gene in plasma plays an important role on cervical cancer, which results in decreased expression of FHIT protein. It can be used to diagnose and evaluate the effect of treatment to cervical cancers.

[Methylation status of the 5' CpG islands in FHIT gene in the plasma and tissues of cervical cancer patients].

To evaluate the methylation status of the 5' CpG islands in FHIT gene using plasma and tissue samples from cervical cancer patients and find a novel marker for non-invasive diagnosis of cervical cancer, methylation-specific PCR (MSP) was employed to examine CpG island methylation in FHIT gene in 151 pretreatment plasma samples and 30 tumor tissue samples obtained from cervical cancer patients. MSP product was cloned and sequenced directly. CpG island methylation of FHIT was detected in 31.13% of the plasma samples, and in 53.33% of the tissue samples. The total concordant rate of methylation status between plasma and tissue samples in FHIT gene was 80.00%. We found a strong positive correlation between FHIT methylation in the plasma and the clinical stage and histological grade of the tumor. The data showed that CpG island methylation of the FHIT gene is prevalent in the plasma and tissue samples from cervical cancer patients. FHIT detection may be used as a non-invasive marker for diagnosis of cervical cancer and prognostic treatment evaluation.

[Studies on cytogeography of Pinellia ternata poliploid complex].

OBJECTIVE: In order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically. METHOD: Cytological and cytogeographical methods were used in the study. RESULT: P. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found. CONCLUSION: The genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.

Preparation and analysis of cSNP chip on hepatocellular carcinoma-related genes.

BACKGROUND: The understanding of cSNPs of cancer-related genes harboring in high frequency loss regions of tumor chromosomes can advance the disclosure of genetic and variant mechanisms of tumorigenesis, and the investigation of cancer susceptibility. In preparing a gene chip for detecting polymorphisms on coding region of genes in hepatocellular carcinoma tissues, some cSNPs are of interest for their potential links with phenotype. METHODS: The genes harboring in loss regions with high frequency of hepatocellular carcinoma (HCC) were selected, the related information of cSNP sequences was obtained from the SNP database (dbSNP) of the National Center for Biotechnology Information (NCBI). Then appropriate primers and oligonucleotide probes were designed according to the SNP sites, and a gene chip for the detection of SNPs was constructed. The chip included 48 cSNPs of 25 hepatocellular carcinoma-related genes. The PCR products labeled by Dig-dUTP were hybridized with the cSNP chip. RESULTS: The sensitivity, influence by probe concentration, and reiteration of the chip were detected, with a high sensitivity of 6X10(-3) ng/mul. The signal of hybridization was reduced with a lower concentration of probe. Seven polymorphisms of caspase 9 (rs2308941)C-->T and DOK2(rs2242241) T-->G, 6 of polymorphisms of EGFL3 (rs947345)A -->G, caspase 9 ( rs2308938) C-->G and PHGDH(rs1801955)T-->A, 5 of polymorphisms of E2F2(rs3218170) G-->A,4 of polymorphisms of MUTYH(rs1140507)T-->C and BNIP3L(rs1055806)G-->T, and 1 of polymorphism of TNFRSF1B (rs1061622)T-->G were detected by the chip in the tissues of 10 HCC. Samples of caspase 9 (rs2308941G) and (rs2308941A) were verified by PCR-SSCP and sequencing. CONCLUSION: The cSNP chip of hepatocellular carcinoma-related genes can accelerate the discovery of polymorphic markers on hepatocellular carcinoma.

[Identification of PCR markers associated with cytoplasmic male sterility in Brassica oleracea var Botrytis].

The homology-based candidate gene method was used to identified the specific PCR markers linked to cytoplasmic male sterility (CMS) in cauliflower( Brassica oleracea var botrytis.). Searching the DNA and protein data-base of NCBI , correlative genes or open reading frames were identified . Analysis of biosoft, based on the conservative regions ,five primers were designed . Among them, only primer P9/P10 produced a 313- bp specific fragment. Identified by individual plant testing , analysis of RT-PCR and dot blot ,this fragment was only existed in CMS cauliflower knxd612. Analysis of the sequence indicated it was high homologous(98%) with orf138 of Ogura CMS radish. Primary result suggested that the cytoplasmic type of CMS cauliflower knxd612 may belong to Ogura type. This research offered a good foundation to further investigate the CMS mechanism of cauliflower in molecular level.

The molecular characterization of maize B chromosome specific AFLPs.

The origin and evolution of B chromosomes could be explained by the specific DNA sequence on them. But the specific sequences known were quite limited. To investigate maize B chromosome sqicific DNA sequeces, maize genomes with and without B chromosomes were analyzed by AFLP. Only 5 markers were found specific to genomes with B chromosomes among about 2000 AFLP markers. Southern hybridization and sequence analysis revealed that only the sequence of M8-2D was a B chromosome specific sequence. This sequence contained the telomeric repeat unit AGG

Methylation of Dickkopf-3 as a prognostic factor in cirrhosis-related hepatocellular carcinoma.

AIM: To investigate the prevalence and time of Dickkopf (DKK) family methylation and its clinical significance in hepatocarcinogenesis. METHODS: Methylation of DKK family genes was quantitatively analyzed in 115 liver tissue samples, including 50 pairs of primary hepatocellular carcinoma (HCC) and matched noncancerous cirrhotic tissue samples, as well as 15 liver cirrhosis biopsy samples. RESULTS: The methylation level of DKK3 was significantly higher in HCC tissue samples than in matched noncancerous cirrhotic tissue samples (P < 0.0001) or in liver cirrhosis biopsy samples (P = 0.0139). Receiver operator characteristic curve analysis confirmed that the percent of methylated reference (PMR) values of DKK3 could effectively discriminate HCC tissue samples from noncancerous tissue samples (AUC = 0.8146) or liver cirrhosis biopsy samples (AUC = 0.7093). Kaplan-Meier survival curves revealed that the progression-free survival time of patients with a higher DKK3 methylation level (PMR > 1%) was significantly shorter than that of those with a lower DKK3 methylation level (PMR < or = 1%) (P = 0.0255). Multivariate Cox analysis indicated that methylated DKK3 was significantly and independently related with a shorter survival time (relative risk = 2.527, 95% CI: 1.063-6.008, P = 0.036) of HCC patients. CONCLUSION: Methylation of DKK3 is an important event in early malignant transformation and HCC progression, and therefore might be a prognostic indicator for risk assessment of HCC.

TGF-beta1 immunohistochemistry and promoter methylation in chronic renal failure rats treated with Uremic Clearance Granules.

The aim of the study was the explain the mechanism related to therapeutic effects of Uremic Clearance Granules (Niaoduqing Keli in Chinese) on adenine-induced Chronic Renal Failure in rats. Thirty 8-week-old male Wistar rats were selected and randomly divided in to 3 groups: Normal Control Group (NCG)consisted of 10 rats, Chronic Renal Failure Pathological Control Group (PCG) 10 rats, and Uremic Clearance Granules Treatment Group (UCG) 10 rats. Each rat in PCG and UCG was fed with adenine-enriched diets, containing 10 g adenine per kg food for 6 weeks. After fed with adenine, each rat in UCG was administered orally with 2 ml solution of Uremic Clearance Granules for 6 weeks. The concentration of Uremic Clearance Granules solution was 0.42 g/ml which was 10 times of human. On days 42 and 84, the serum levels of creatinine, Blood Urea Nitrogen and homocysteine were determined. The methylation of TGFbeta1 promoter was tested by methylation-specific PCR. TGF-beta1 mRNA and protein expression in rat renal cortex were analyzed by real-time RT-PCR and Immunohistochemistry. (1) Experimented on model of Chronic Renal Failure in rats, the preparation was proved to be able to reduce serum creatinine, Blood Urea Nitrogen, and homocysteine (p<0.05), improve renal function. (2) The expression of TGF-beta1 in mRNA and protein level were down-regulated. (3) TGF-beta1 promoter was demethylated at some loci in PCG, and was recovered in UCG. After treatment with Uremic Clearance Granules, the Chronic Renal Failure Wistar rat's kidney function was recovered. The recovery may be result of the remethylation of TGF-beta1 promoter and then lead to TGF-beta1 be transcripted and translated normally. The experimental study explain the molecular mechanism by which Uremic Clearance Granules treat Chronic Renal Failure.

[Analysis of the level and pattern of genomic DNA methylation in different ploidy watermelons by MSAP (Citrullus lanatus)].

DNA methylation is one of the major epigenetic modifications. It is very important to the regulation of gene expression. In present study, an autoploidy series (2x, 3x and 4x) in watermelon (Citrullus lanatus) was constructed and MSAP (Methylation-Sensitive Amplification Polymorphism) analysis was conducted to elucidate the level and pattern of DNA methylation at CCGG sites in different ploidy watermelons. Totally, 1883 genetic loci were produced by 23 pairs of selective primers, of which 647, 655 and 581 sites were detected in diploid, autotriploid and autotetraploid, respectively. The methylation sites were 181, 150 and 159, and the corresponding total methylation ratios were 28.0%, 22.9% and 27.4% in 2x, 3x and 4x, respectively, of which the fully methylation sites were 121, 80 and 82, and the corresponding fully methylation ratios were 18.7%, 12.2% and 14.1%. Further analysis of the pattern of DNA methylation suggested that compared 4x with 2x, about half of detected sites (54.4%) shown changes of DNA methylation patterns. Similarly, compared 4x with 3x, 45.4% sites also shown changes of DNA methylation patterns. Moreover, the trend of DNA methylation adjustment mainly involved increase of DNA methylation levels in 4x. However, compared 3x with 2x or 4x, although the changes of DNA methylation pattern also widely occurred, which involved 41.6% (compared 3x with 2x) and 45.4% (compared 3x with 4x) sites, respectively, the trend of DNA methylation adjustment mainly involved decrease of DNA methylation levels in 3x. All these results indicated that DNA methylation events were widely existed in different ploidy watermelons. However, not only based on the total DNA methylation ratio or fully DNA methylation ratio, the results both implied that the DNA methylation levels were not closely associated with the autopolyploidy level in watermelon. Autotriploid watermelon shows obvious low level of DNA methylation. Analysis of DNA methylation patterns also suggested that the adjustment of DNA methylation patterns in autotriploid mainly involved demethylation events, implying the unusual characteristic of DNA methylation status in 3x watermelon. The present results are valuable to further explore the nature of triploid vigor and autopolyploidizaion in watermelon from the view of epigenetics.

[Isolation and identification of specific sequences correlated to cytoplasmic male sterility and fertile maintenance in cauliflower (Brassica oleracea var. botrytis)].

Analysis of ISSR (Inter-Simple Sequence Repeat) and DDRT-PCR (Differential Display Reverse Transcriptase Polymerase Chain Reaction) was performed between cytoplasmic male sterility cauliflower ogura-A and its corresponding maintainer line ogura-B. Totally, 306 detectable bands were obtained by ISSR using thirty oligonucleotide primers. Commonly, six to twelve bands were produced per primer. Among all these primers only the amplification of primer ISSR3 was polymorphic, an 1100 bp specific band was only detected in maintainer line, named ISSR3(1100). Analysis of this sequence indicated that ISSR3(1100) was high homologous with the corresponding sequences of mitochondrial genome in Brassica napus and Arabidopsis thaliana,which suggested that ISSR3(1100) may derive from mitochondrial genome in cauliflower. To carry out DDRT-PCR analysis, three anchor primers and fifteen random primers were selected to combine. Totally, 1122 bands from 1 000 bp to 50 bp were detected. However, only four bands, named ogura-A 205, ogura-A383, ogura-B307 and ogura-B352, were confirmed to be different display in both lines. This result was further identified by reverse Northern dot blotting analysis. Among these four bands, ogura-A205 and ogura-A383 only express in cytoplasmic male sterility line, while ogura-B307 and ogura-B352 were only detected in maintainer line. Analysis of these sequences indicated that it was the first time that these four sequences were reported in cauliflower. Interestingly, ogura-A205 and ogura-B307 did not exhibit any similarities to other reported sequences in other species, more investigations were required to obtain further information. ogura-A383 and ogura-B352 were also two new sequences, they showed high similarities to corresponding chloroplast sequences of Arabidopsis thaliana and Brassica rapa subsp. pekinensis. So we speculated that these two sequences may derive from chloroplast genome. All these results obtained in this study offer new and significant information to investigate the molecular mechanism of cytoplasmic male sterility and fertile maintenance in cauliflower.

[Identification and analysis of the specific molecular marker associated with fertile maintenance of cytoplasmic male sterility cauliflower].

Analysis of RAPD (Randomly Amplification Polymorphic DNA) was performed between cytoplasmic male sterility line and its maintainer line of cauliflower. Totally 2160 detectable bands were obtained by RAPD using 406 10-bp random primers. Averagely, 5 to 10 bands were produced per primer. Among all the primers only the amplification of primer S2121 was polymorphic in two lines. A 934-bp specific band was only detected in maintainer line. After cloning and sequencing, specific primers were designed to transform the RAPD marker to PCR marker, which was named S2121(900). To identify the specificity of S2121(900), southern dot blotting was performed. To further identify its specificity, individual plant and candidate materials testing were also performed. All these results indicated that the S2121(900) was specific. It can be used to screen the maintainer lines of cauliflower in early stage. Analysis of the sequence suggested that this fragment was high homologous with the part sequences of mitochondrial genome in Brassica napus and Arabidopsis thaliana. So we supposed the S2121(900) may also derive from mitochondrial genome. Our results here offer new clues for explaining the molecular mechanism of cytoplasic male sterility of cauliflower in other way.

Methylation-based molecular margin analysis in hepatocellular carcinoma.

The positive surgical margins are associated with postsurgical recurrence in hepatocellular carcinoma patients, and molecular margin analysis is considered more sensitive in detecting preneoplastic lesions than conventional histological margin examination. To evaluate the feasibility of methylation-based molecular margin analysis in HCC and explore its clinical application, we investigated CDKN2A methylation status in the surgical margins of 20 HCC patients using a nested BS-MSP protocol and compared the methylation patterns in resection margins with those in the corresponding tumor and adjacent nonmalignant tissues. The results showed that a considerable frequency (35%, 7 of 20) of CDKN2A methylation was present in histologically negative margins, and methylation pattern analysis might be valuable for studying the cellular origin of recurrent carcinoma. Therefore, methylation-based molecular surgical margin analysis offers a promising tool in prognosis for HCC patients who underwent hepatectomy.