MALAT1 functions as a transcriptional promoter of MALAT1::GLI1 fusion for truncated GLI1 protein expression in cancer.

BACKGROUND: The long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a cancer biomarker. Furthermore, fusion of the MALAT1 gene with glioma-associated oncogene 1 (GLI1) is a diagnostic marker of plexiform fibromyxoma and gastroblastoma; however, the function of this fusion gene remains unexplored. METHOD: In this study, we elucidate the structure and function of the MALAT1::GLI1 fusion gene. To this end, we determined a transcriptional start site (TSS) and promoter region for truncated GLI1 expression using rapid amplification of the 5' cDNA end and a luciferase reporter assay in cultured cells transfected with a plasmid harboring the MALAT1::GLI1 fusion gene. RESULTS: We found that the TATA box, ETS1 motif, and TSS were located in MALAT1 and that MALAT1 exhibited transcriptional activity and induced expression of GLI1 from the MALAT1::GLI1 fusion gene. Truncated GLI1, lacking SUMOylation and SUFU binding sites and located in the nucleus, upregulated mRNA expression of GLI1 target genes in the hedgehog signaling pathway. CONCLUSIONS: We demonstrate a distinct and alternative function of MALAT1 as a transcriptional promoter for expression of the MALAT1::GLI1 fusion gene. Our findings will aid future research on MALAT1 and its fusion gene partners.

Gallbladder microbiota composition is associated with pancreaticobiliary and gallbladder cancer prognosis.

BACKGROUND: The microbial population of the intestinal tract and its relationship to specific diseases has been extensively studied during the past decade. However, reports characterizing the bile microbiota are rare. This study aims to investigate the microbiota composition in patients with pancreaticobiliary cancers and benign diseases by 16S rRNA gene amplicon sequencing and to evaluate its potential value as a biomarker for the cancer of the bile duct, pancreas, and gallbladder. RESULTS: We enrolled patients who were diagnosed with cancer, cystic lesions, and inflammation of the pancreaticobiliary tract. The study cohort comprised 244 patients. We extracted microbiome-derived DNA from the bile juice in surgically resected gallbladders. The microbiome composition was not significantly different according to lesion position and cancer type in terms of alpha and beta diversity. We found a significant difference in the relative abundance of Campylobacter, Citrobacter, Leptotrichia, Enterobacter, Hungatella, Mycolicibacterium, Phyllobacterium and Sphingomonas between patients without and with lymph node metastasis. CONCLUSIONS: There was a significant association between the relative abundance of certain microbes and overall survival prognosis. These microbes showed association with good prognosis in cholangiocarcinoma, but with poor prognosis in pancreatic adenocarcinoma, and vice versa. Our findings suggest that pancreaticobiliary tract cancer patients have an altered microbiome composition, which might be a biomarker for distinguishing malignancy.

Genome Editing Using Cas9 Ribonucleoprotein Is Effective for Introducing PDGFRA Variant in Cultured Human Glioblastoma Cell Lines.

Many variants of uncertain significance (VUS) have been detected in clinical cancer cases using next-generation sequencing-based cancer gene panel analysis. One strategy for the elucidation of VUS is the functional analysis of cultured cancer cell lines that harbor targeted gene variants using genome editing. Genome editing is a powerful tool for creating desired gene alterations in cultured cancer cell lines. However, the efficiency of genome editing varies substantially among cell lines of interest. We performed comparative studies to determine the optimal editing conditions for the introduction of platelet-derived growth factor receptor alpha (PDGFRA) variants in human glioblastoma multiforme (GBM) cell lines. After monitoring the copy numbers of PDGFRA and the expression level of the PDGFRα protein, four GBM cell lines (U-251 MG, KNS-42, SF126, and YKG-1 cells) were selected for the study. To compare the editing efficiency in these GBM cell lines, the modes of clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) delivery (plasmid vs. ribonucleoprotein (RNP)), methods of transfection (lipofection vs. electroporation), and usefulness of cell sorting were then evaluated. Herein, we demonstrated that electroporation-mediated transfer of Cas9 with single-guide RNA (Cas9 RNP complex) could sufficiently edit a target nucleotide substitution, irrespective of cell sorting. As the Cas9 RNP complex method showed a higher editing efficiency than the Cas9 plasmid lipofection method, it was the optimal method for single-nucleotide editing in human GBM cell lines under our experimental conditions.

PCP4/PEP19 downregulates neurite outgrowth via transcriptional regulation of Ascl1 and NeuroD1 expression in human neuroblastoma M17 cells.

Purkinje cell protein 4/peptide 19 (PCP4/PEP19) is 7.6 kDa peptide originally found in Purkinje cells. PCP4/PEP19 is a differentiation maker of Purkinje cells, where it functions as an antiapoptotic factor. Cerebral neuronal cells also express PCP4/PEP19, which may be related to neuronal cell survival. However, evidence suggests that PCP4/PEP19 may also be involved in neuronal differentiation. Here, we investigated the effects of PCP4/PEP19 expression on neuronal differentiation by analyzing neurite outgrowth, and expression of neuronal differentiation markers in cultured human neuroblastoma M17 cells. When PCP4/PEP19 expression was reduced by siRNA-mediated knockdown, neurite outgrowth was significantly increased. Among many differentiation markers tested, expression of NeuroD1 was increased, while that of Ascl1 was decreased upon PCP4/PEP19 knockdown. Furthermore, luciferase reporter assays revealed that PCP4/PEP19 knockdown upregulated NeuroD1 and downregulated Ascl1 expression, at the transcriptional level. These results suggest a new function of PCP4/PEP19, which suppresses neurite outgrowth and neuronal differentiation through the regulation of NeuroD1 and Ascl1 expression in M17 cells. Furthermore, immunohistochemical studies showed that PCP4/PEP19 localizes in the nuclei of human neuroblastoma cells. Therefore, PCP4/PEP19 may also be an intranuclear negative regulator of neuronal differentiation and may thus be a potential therapeutic target to promote cellular differentiation in human neuroblastoma.

A tailored next-generation sequencing panel identified distinct subtypes of wildtype IDH and TERT promoter glioblastomas.

Central nervous system tumors are classified based on an integrated diagnosis combining histology and molecular characteristics, including IDH1/2 and H3-K27M mutations, as well as 1p/19q codeletion. Here, we aimed to develop and assess the feasibility of a glioma-tailored 48-gene next-generation sequencing (NGS) panel for integrated glioma diagnosis. We designed a glioma-tailored 48-gene NGS panel for detecting 1p/19q codeletion and mutations in IDH1/2, TP53, PTEN, PDGFRA, NF1, RB1, CDKN2A/B, CDK4, and the TERT promoter (TERTp). We analyzed 106 glioma patients (grade II: 19 cases, grade III: 23 cases, grade IV: 64 cases) using this system. The 1p/19q codeletion was detected precisely in oligodendroglial tumors using our NGS panel. In a cohort of 64 grade Ⅳ gliomas, we identified 56 IDH-wildtype glioblastomas. Within these IDH-wildtype glioblastomas, 33 samples (58.9%) showed a mutation in TERTp. Notably, PDGFRA mutations and their amplification were more commonly seen in TERTp-wildtype glioblastomas (43%) than in TERTp-mutant glioblastomas (6%) (P = .001). Hierarchical molecular classification of IDH-wildtype glioblastomas revealed 3 distinct groups of IDH-wildtype glioblastomas. One major cluster was characterized by mutations in PDGFRA, amplification of CDK4 and PDGFRA, homozygous deletion of CDKN2A/B, and absence of TERTp mutations. This cluster was significantly associated with older age (P = .021), higher Ki-67 score (P = .007), poor prognosis (P = .012), and a periventricular tumor location. We report the development of a glioma-tailored NGS panel for detecting 1p/19q codeletion and driver gene mutations on a single platform. Our panel identified distinct subtypes of IDH- and TERTp-wildtype glioblastomas with frequent PDGFRA alterations.

Protective Effects of Peroxiredoxin 4 (PRDX4) on Cholestatic Liver Injury.

Accumulating evidence indicates that oxidative stress plays a critical role in initiating the progression of inflammatory and fibrotic liver diseases, including cholestatic hepatitis. Peroxiredoxin 4 (PRDX4) is a secretory antioxidase that protects against oxidative damage by scavenging reactive oxygen species (ROS) in both the intracellular compartments and extracellular space. In this study, we examined the in vivo net effects of PRDX4 overexpression in a murine model of cholestasis. To induce cholestatic liver injury, we subjected C57BL/6J wild-type (WT) or human PRDX4 (hPRDX4) transgenic (Tg) mice to sham or bile duct ligation (BDL) surgery for seven days. Our results showed that the liver necrosis area was significantly suppressed in Tg BDL mice with a reduction in the severity of liver injuries. Furthermore, PRDX4 overexpression markedly reduced local and systemic oxidative stress generated by BDL. In addition, suppression of inflammatory cell infiltration, reduced proliferation of hepatocytes and intrahepatic bile ducts, and less fibrosis were also found in the liver of Tg BDL mice, along with a reduced mortality rate after BDL surgery. Interestingly, the composition of the hepatic bile acids (BAs) was more beneficial for Tg BDL mice than for WT BDL mice, suggesting that PRDX4 overexpression may affect BA metabolism during cholestasis. These features indicate that PRDX4 plays an important role in protecting against liver injury following BDL and might be a promising therapeutic modality for cholestatic diseases.

Assessment of tumor characteristics based on glycoform analysis of membrane-tethered MUC1.

This corrects the article DOI: 10.1038/labinvest.2017.53.

Assessment of tumor characteristics based on glycoform analysis of membrane-tethered MUC1.

Clinical tissue specimens are useful for pathological diagnosis, which is, in some cases, supported by visualization of biomolecule localization. In general, diagnostic specificity in molecular pathology is increased by the acquisition of a probe to distinguish the modification of isomers. Although glycosylation is one of the candidate modifications in a protein, comparative glycan analysis of disease-associated proteins derived from a single tissue section is still challenging because of the lack of analytical sensitivity. Here we demonstrate a possible method for differential glycoform analysis of an endogenous tumor-associated glycoprotein MUC1 by an antibody-overlay lectin microarray. Tissue sections (5 µm thick) of patients with cholangiocarcinoma (CCA; n=21) and pancreatic ductal adenocarcinoma (PDAC; n=50) were stained with an anti-MUC1 antibody MY.1E12 that was established as a monoclonal antibody recognizing an MUC1 glycosylation isoform with a sialyl-core 1 structure (NeuAcα2-3galactosyl ß1-3-N-acetylgalactosamine). MY.1E12-positive tissue areas (2.5 mm2) were selectively dissected with a laser capture microdissection procedure. The membrane MUC1 was enriched by immunoprecipitation with MY.1E12 and subjected to lectin microarray analysis. Even though the reactivities of MY.1E12 between CCA and PDAC were similar, the lectin-binding patterns varied. We found Maackia amurensis leukoagglutinin and pokeweed lectin distinguished MY.1E12-reactive MUC1 of CCA from that of PDAC. Moreover, MUC1 with M. amurensis hemagglutinin (MAH) reactivity potentially reflected the degree of malignancy. These results were confirmed with MAH-MY.1E12 double fluorescent immunostaining. These glycan changes on MUC1 were detected with high sensitivity owing to the cluster effect of immobilized lectins on a tandem repeat peptide antigen covered with highly dense glycosylation such as mucin. Our approach provides the information to investigate novel glycodynamics in biology, for example, glycoalteration, as well as diseases related to not only MUC1 but also other membrane proteins.

Two autopsy cases of severe fever with thrombocytopenia syndrome (SFTS) in Japan: a pathognomonic histological feature and unique complication of SFTS.

We report two autopsy cases of severe fever with thrombocytopenia syndrome (SFTS) with a high fatality rate in aged Japanese patients. Both cases were caused by a tick-bite. The pathognomonic histological feature was necrotizing lymphadenitis of systemic lymphoid tissue with SFTS viruses and SFTSV-RNA copies. Marked fungal infections were also observed in the lungs of both patients. Since cellular immune function may be suppressed in SFTS patients, physicians should be aware of possible fungal infections.

Methylation-Specific Electrophoresis.

Methylation of CpG sites in the promoter region of genomic DNA is an important epigenetic modification that plays a critical role in gene regulation, particularly in gene silencing. Epigenetic abnormalities, along with genetic alterations, are implicated in carcinogenesis and cancer progression. Numerous studies have investigated the role of epigenetics in cancer using various tools to assess DNA methylation. However, conventional analysis methods for DNA methylation require a large amount of DNA but lack higher sensitivity, making them unsuitable for analysis of samples with high heterogeneity, such as tumor tissues. In this study, we introduce a novel electrophoresis method named "methylation-specific electrophoresis (MSE)," which utilizes a denaturing gradient acrylamide gel. We demonstrate the applicability of the MSE method for DNA methylation analysis of the mucin gene as an example.

Cervical Cytology Preserves Histologically Detected Surface Epithelial Slackening, Unique to the POLE Mutation-subtype in Endometrial Cancer.

BACKGROUND/AIM: Among the four genomic subtypes of endometrial cancer, distinguishing between the DNA polymerase epsilon mutation (POLEmut) and no specific molecular profile (NSMP) subtypes requires genomic profiling owing to the lack of surrogate immunohistochemical markers. We have previously found that, histologically, the POLEmut-subtype exhibits surface epithelial slackening (SES). Therefore, to improve subtype identification, we aimed to extract cytological features corresponding to SES in POLEmut-subtype cervical cytology specimens. MATERIALS AND METHODS: We analyzed 104 endometrial cancer cervical cytology specimens, with integrative diagnosis confirmation via histology, immunohistochemistry, and genomic profiling. Cytological features were evaluated for the presence of atypical glandular cells, atypical cell appearance in single cells and clusters, and cytological SES and the presence of tumor-infiltrating inflammatory cells in clusters. RESULTS: Based on cervical cytology, the POLEmut- and p53mut-subtypes exhibited more frequent atypical cells in smaller clusters, giant tumor cells, and cytological SES patterns than the NSMP-subtype. Tumor-infiltrating lymphocytes were frequent in the POLEmut- and mismatch repair-deficient subtypes. CONCLUSION: Histologically-detected SES as well as other endometrial cancer features may be preserved in the atypical cell clusters observed in cervical cytology specimens. Cytological detection of SES and of smaller clusters of atypical cells and inflammatory cells with moderate atypia are suggestive of POLEmut-subtype. Integrative diagnosis including genomic profiling remains critical for diagnostic confirmation.

Exercise Suppresses Head and Neck Squamous Cell Carcinoma Growth via Oncostatin M.

Major advances have been made in cancer treatment, but the prognosis for elderly cancer patients with sarcopenia and frailty remains poor. Myokines, which are thought to exert preventive effects against sarcopenia, have been reported to be associated with the prognosis of various cancers, but their effect on head and neck squamous cell carcinoma (HNSCC) is unknown. The aim of this study was to clarify the influence of exercise on the control of HNSCC and to examine the underlying mechanism involved. Mice were injected with HSC-3-M3 cells, a human cell line of highly metastatic and poorly differentiated tongue cancer, at the beginning of the study. Just prior to transplantation, blood was collected from the mice, and the levels of myokines were measured by ELISA. Oncostatin M (OSM), a selected myokine, was added to HSC-3-M3 cells, after which the cell proliferation ability, cell cycle, and protein expression were analyzed in vitro. Tumor cell viability was lower (control: 100%, exercise: 75%), tumors were smaller (control: 26.2 mm3, exercise: 6.4 mm3), and survival was longer in the exercise group than in the control group in vivo. OSM inhibited HSC-3-M3 cell proliferation in a concentration-dependent manner in vitro. The addition of OSM increased the proportion of cells in the G0/G1 phase, decreased the proportion of cells in the G2/M phase, and increased the expression of the CDK inhibitors p21 and p27. These results indicate that exercise may directly inhibit the proliferation of HNSCC cell lines via OSM.

Identification of Neck Lymph Node Metastasis-Specific microRNA-Implication for Use in Monitoring or Prediction of Neck Lymph Node Metastasis.

MicroRNAs (miRNAs) have attracted attention as non-invasive cancer biomarkers in various cancers; however, they have not been adequately investigated in oral squamous cell carcinoma (OSCC). This study investigated the diagnostic performance of serum-derived miRNAs at initial diagnosis for primary neck lymph node metastasis and the predictive performance for late neck lymph node metastasis based on long-term (up to approximately 8 years) follow-up of patients with OSCC. The expression of miRNAs in 40 patients with OSCC was quantified using real-time PCR (qPCR), and a comprehensive statistical analysis of the correlation of miRNA expression for primary and late neck lymph node metastases was performed. For the diagnosis of primary neck lymph node metastases, miR-423 and miR-125 were accurate. The miRNA index for primary metastasis diagnosis (miR-PM) calculated by regression analysis showed high diagnostic accuracy. The miR-5100 was useful for predicting late neck lymph node metastases. The miRNA index for late metastasis prediction (miR-LM) calculated using regression analysis showed high prediction accuracy. MiRNAs were useful for diagnosing primary neck lymph node metastases in OSCC and predicting late neck lymph node metastases. It may help to consider individualized treatment, including follow-up, surgical methods, and postoperative management.

"Surface epithelial slackening" pattern in endometrioid carcinoma: A morphological feature for differentiating the POLE mutation-subtype from the no specific molecular profile subtype.

Endometrial cancers are classified into mismatch repair (MMR) deficient- (MMRd), p53 mutation- (p53mut), DNA polymerase epsilon (POLE) mutation (POLEmut), and no specific molecular profile (NSMP) subtypes according to The Cancer Genome Atlas (TCGA). The distinction between POLEmut and NSMP subtypes is made on the basis of molecular analysis because the specific histological and immunohistochemical features of these two subtypes are still unknown. In this study, we analyzed histological features by scoring the presence of a mucinous pool, giant cells, clear cells, keratinization, neutrophilic abscess, and surface proliferating pattern in 82 cases of endometrial cancers in which an integrative diagnosis was confirmed by immunohistochemistry and genomic profiles showing POLE mutations, tumor mutation burden, and microsatellite instability. In contrast to the hierarchical branching of micropapillary proliferation observed in serous carcinoma, POLEmut-subtype endometrioid carcinomas often showed a surface epithelial slackening (SES) pattern in the tumor cells facing the uterine surface. The POLEmut subtype exhibited higher scores for clear cells and SES patterns than the other three subtypes. The scores for giant cells, clear cells, and the SES pattern were significantly higher in the POLEmut subtype than in the NSMP subtype, suggesting that these morphometric parameters are useful for differentiating POLEmut- and NSMP-subtype endometrioid carcinomas, although genomic profiling is still necessary for a definite molecular diagnosis.

Distribution and favorable prognostic implication of genomic EGFR alterations in IDH-wildtype glioblastoma.

BACKGROUND: We aimed to evaluate the mutation profile, transcriptional variants, and prognostic impact of the epidermal growth factor receptor (EGFR) gene in isocitrate dehydrogenase (IDH)-wildtype glioblastomas (GBMs). METHODS: We sequenced EGFR, evaluated the EGFR splicing profile using a next-generation sequencing oncopanel, and analyzed the outcomes in 138 grade IV IDH-wildtype GBM cases. RESULTS: EGFR mutations were observed in 10% of GBMs. A total of 23.9% of the GBMs showed EGFR amplification. Moreover, 25% of the EGFR mutations occurred in the kinase domain. Notably, EGFR alterations were a predictor of good prognosis (p = 0.035). GBM with EGFR alterations was associated with higher Karnofsky Performance Scale scores (p = 0.014) and lower Ki-67 scores (p = 0.005) than GBM without EGFR alterations. EGFRvIII positivity was detected in 21% of EGFR-amplified GBMs. We identified two other EGFR variants in GBM cases with deletions of exons 6-7 (Δe 6-7) and exons 2-14 (Δe 2-14). In one case, the initial EGFRvIII mutation transformed into an EGFR Δe 2-14 mutation during recurrence. CONCLUSIONS: We found that the EGFR gene profiles of GBM differ among cohorts and that EGFR alterations are good prognostic markers of overall survival in patients with IDH-wildtype GBM. Additionally, we identified rare EGFR variants with longitudinal and temporal transformations of EGFRvIII.

Characterization and treatment of gemcitabine- and cisplatin-resistant bladder cancer cells with a pan-RAS inhibitor.

Combination chemotherapy with gemcitabine and cisplatin (GC) is recommended as the primary treatment for advanced bladder cancer (BC). However, the benefits of this approach are limited owing to the acquisition of drug resistance. Here, we found that gemcitabine-resistant and cisplatin-resistant BCs do not exhibit cross-resistance, and that these BCs exhibit different mRNA patterns, as revealed using RNA sequence analysis. To overcome drug resistance, we used the newly developed pan-RAS inhibitor Compound 3144. Compound 3144 inhibited cell viability through suppression of RAS-dependent signaling in gemcitabine- and cisplatin-resistant BCs. RNA sequencing revealed that several genes and pathways, particularly those related to the cell cycle, were significantly downregulated in Compound 3144-treated BCs. These findings provide insights into potential therapeutic strategies for treating BC.

Favorable prognostic impact of phosphatase and tensin homolog alterations in wild-type isocitrate dehydrogenase and telomerase reverse transcriptase promoter glioblastoma.

Background: Telomerase reverse transcriptase promoter (TERTp) mutations are a biological marker of glioblastoma; however, the prognostic significance of TERTp mutational status is controversial. We evaluated this impact by retrospectively analyzing the outcomes of patients with isocitrate dehydrogenase (IDH)- and TERTp-wild-type glioblastomas. Methods: Using custom next-generation sequencing, we analyzed 208 glioblastoma samples harboring wild-type IDH. Results: TERTp mutations were detected in 143 samples (68.8%). The remaining 65 (31.2%) were TERTp-wild-type. Among the TERTp-wild-type glioblastoma samples, we observed a significant difference in median progression-free survival (18.6 and 11.4 months, respectively) and overall survival (not reached and 15.7 months, respectively) in patients with and without phosphatase and tensin homolog (PTEN) loss and/or mutation. Patients with TERTp-wild-type glioblastomas with PTEN loss and/or mutation were younger and had higher Karnofsky Performance Status scores than those without PTEN loss and/or mutation. We divided the patients with TERTp-wild-type into 3 clusters using unsupervised hierarchical clustering: Good (PTEN and TP53 alterations; lack of CDKN2A/B homozygous deletion and platelet-derived growth factor receptor alpha (PDGFRA) alterations), intermediate (PTEN alterations, CDKN2A/B homozygous deletion, lack of PDGFRA, and TP53 alterations), and poor (PDGFRA and TP53 alterations, CDKN2A/B homozygous deletion, and lack of PTEN alterations) outcomes. Kaplan-Meier survival analysis indicated that these clusters significantly correlated with the overall survival of TERTp-wild-type glioblastoma patients. Conclusions: Here, we report that PTEN loss and/or mutation is the most useful marker for predicting favorable outcomes in patients with IDH- and TERTp-wild-type glioblastomas. The combination of 4 genes, PTEN, TP53, CDKN2A/B, and PDGFRA, is important for the molecular classification and individual prognosis of patients with IDH- and TERTp-wild-type glioblastomas.

Aberrant DNA methylation of tumor-related genes in oral rinse: a noninvasive method for detection of oral squamous cell carcinoma.

BACKGROUND: The early detection of oral squamous cell carcinoma (OSCC) is important, and a screening test with high sensitivity and specificity is urgently needed. Therefore, in this study, the authors investigated the methylation status of tumor-related genes with the objective of establishing a noninvasive method for the detection of OSCC. METHODS: Oral rinse samples were obtained from 34 patients with OSCC and from 24 healthy individuals (controls). The methylation status of 13 genes was determined by using methylation-specific polymerase chain reaction analysis and was quantified using a microchip electrophoresis system. Promoter methylation in each participant was screened by receiver operating characteristic analysis, and the utility of each gene's methylation status, alone and in combination with other genes, was evaluated as a tool for oral cancer detection. RESULTS: Eight of the 13 genes had significantly higher levels of DNA methylation in samples from patients with OSCC than in controls. The genes E-cadherin (ECAD), transmembrane protein with epidermal growth factor-like and 2 follistatin-like domains 2 (TMEFF2), retinoic acid receptor beta (RARß), and O-6 methylguanine DNA methyltransferase (MGMT) had high sensitivity (>75%) and specificity for the detection of oral cancer. OSCC was detected with 100% sensitivity and 87.5% specificity using a combination of ECAD, TMEFF2, RARß, and MGMT and with 97.1% sensitivity and 91.7% specificity using a combination of ECAD, TMEFF2, and MGMT. CONCLUSIONS: The aberrant methylation of a combination of marker genes present in oral rinse samples was used to detect OSCC with >90% sensitivity and specificity. The detection of methylated marker genes from oral rinse samples has great potential for the noninvasive detection of OSCC.

The application of methylation specific electrophoresis (MSE) to DNA methylation analysis of the 5' CpG island of mucin in cancer cells.

BACKGROUND: Methylation of CpG sites in genomic DNA plays an important role in gene regulation and especially in gene silencing. We have reported mechanisms of epigenetic regulation for expression of mucins, which are markers of malignancy potential and early detection of human neoplasms. Epigenetic changes in promoter regions appear to be the first step in expression of mucins. Thus, detection of promoter methylation status is important for early diagnosis of cancer, monitoring of tumor behavior, and evaluating the response of tumors to targeted therapy. However, conventional analytical methods for DNA methylation require a large amount of DNA and have low sensitivity. METHODS: Here, we report a modified version of the bisulfite-DGGE (denaturing gradient gel electrophoresis) using a nested PCR approach. We designated this method as methylation specific electrophoresis (MSE). The MSE method is comprised of the following steps: (a) bisulfite treatment of genomic DNA, (b) amplification of the target DNA by a nested PCR approach and (c) applying to DGGE. To examine whether the MSE method is able to analyze DNA methylation of mucin genes in various samples, we apply it to DNA obtained from state cell lines, ethanol-fixed colonic crypts and human pancreatic juices. RESULT: The MSE method greatly decreases the amount of input DNA. The lower detection limit for distinguishing different methylation status is < 0.1% and the detectable minimum amount of DNA is 20 pg, which can be obtained from only a few cells. We also show that MSE can be used for analysis of challenging samples such as human isolated colonic crypts or human pancreatic juices, from which only a small amount of DNA can be extracted. CONCLUSIONS: The MSE method can provide a qualitative information of methylated sequence profile. The MSE method allows sensitive and specific analysis of the DNA methylation pattern of almost any block of multiple CpG sites. The MSE method can be applied to analysis of DNA methylation status in many different clinical samples, and this may facilitate identification of new risk markers.

Pathobiological implications of MUC16/CA125 expression in intrahepatic cholangiocarcinoma-mass forming type.

OBJECTIVES: MUC16 carries the peptide epitope CA125, which is well known as a marker of ovarian cancer. High serum levels of MUC16 (CA125) have been reported not only in patients with ovarian cancer but also in patients with liver diseases. We evaluated the expression of MUC16 in intrahepatic cholangiocarcinoma-mass forming type (ICC-MF) tissues. METHODS: We examined the expression of MUC16 by immunohistochemical analyses using the monoclonal antibody M11 in ICC-MF tissues from 63 patients. To compare the prevalence of each mucin expression by clinicopathological features, appropriate statistical analysis was performed. RESULTS: MUC16 was detected in 48% of samples (30/63). After adjusting for the effects of other prognostic factors, multivariate survival analysis revealed that MUC16 expression is a significant independent factor of poor prognosis (p = 0.005). CONCLUSION: The current results indicate that MUC16 expression is a prognostic factor of poor survival in ICC-MF.