Fas signaling induces stemness properties in colorectal cancer by regulation of Bmi1.

Fas signaling promotes colorectal cancer (CRC) metastasis by inducing epithelial-mesenchymal transition (EMT). The acquisition of EMT properties in turn induces stemness but the mechanism by which Fas signaling contributes to it still remains unclear. Hence, the aim of this study was to investigate how Fas signaling regulates CRC stemness. For this purpose, soft agar assay, sphere formation assay, cell survival analysis, immunoblot, qRT-PCR, chromatin immunoprecipitation, and luciferase reporter assay were performed. Expression of FasL, Bmi1, and the miR-200c in CRC specimens was examined through immunohistochemistry, qRT-PCR, and immunoblot. In our study, Fas signaling induced stem cell properties in CRC specimens, relying on ERK1/2 MAPK pathway, with Bmi1 being mainly responsible for FasL-induced stemness. FasL treatment promoted Bmi1 expression by inhibiting miR-200c, which targets Bmi1 3'UTR region. Furthermore, FasL-induced Zeb1 binded with miR-200c promoter and inhibited its expression. Moreover, FasL-induced ß-catenin nuclear expression promoted Zeb1 expression by binding with Zeb1 promoter. GSK-3ß, which regulates ß-catenin, was inhibited by FasL-induced ERK1/2 MAPK signaling. Finally, FasL and Bmi1 expression in clinical samples increased during CRC progression, and a positive correlation between them was observed. Patients with high FasL and Bmi1 expression had a worse prognosis than patients with low expression. In conclusion, our results showed that Fas signaling can promote stemness in CRC through the modulation of Bmi1 expression via the ERK1/2 MAPK/GSK-3ß/ß-catenin/Zeb1/miR-200c axis, suggesting that Fas signaling-based cancer therapies should be administered cautiously, as the activation of this pathway not only leads to apoptosis but also induces stemness in CRC.

Comparison of endoscopic submucosal tunneling dissection and thoracoscopic enucleation for the treatment of esophageal submucosal tumors.

BACKGROUND AND AIMS: Endoscopic submucosal tunneling dissection (ESTD) has been proved to be safe and effective for removal of esophageal submucosal tumors (SMTs) and can maintain the mucosal integrity compared with other endoscopic methods. The aim of the study was to estimate the safety and efficacy of ESTD as well as compare its efficacy with thoracoscopic enucleation for esophageal SMTs, which is used increasingly as a minimally invasive approach. METHODS: We retrospectively collected the clinical data of patients with esophageal SMTs <40 mm who underwent ESTD or thoracoscopic enucleation at Nanfang Hospital between January 2008 and August 2016. Epidemiologic data (sex, age), tumor location, tumor size, en bloc resection rate, adverse events, pathologic results, length of postoperative hospital stay, and cost were compared between ESTD and thoracoscopic enucleation. RESULTS: A total of 126 patients were included. A total of 74 patients underwent ESTD, and the other 52 underwent thoracoscopic enucleation. There was no significant difference between the 2 groups in sex, age, tumor size, hospitalization expense, infection, adverse events, and en bloc resection rate (P < .05). However, patients in the ESTD group had a shorter operating time, less estimated blood loss, shorter length of postoperative hospital stay, and lower chest pain level (P < .05). Kaplan-Meier curves for disease-free survival also showed no statistically significant difference between ESTD and thoracoscopic enucleation groups during the median follow-up of 19.5 and 42 months, respectively. CONCLUSIONS: The treatment efficacy was comparable between the ESTD and thoracoscopic enucleation for esophageal SMTs <40 mm. However, there was a significant advantage in the ESTD group for a shorter operating time, reduced postoperative chest pain, and shorter hospitalization.

The accuracy of confocal laser endomicroscopy, narrow band imaging, and chromoendoscopy for the detection of atrophic gastritis.

OBJECTIVE: The aim of this study was to compare chromoendoscopy (CE), narrow band imaging (NBI), and confocal laser endomicroscopy (CLE) in diagnosing atrophic gastritis. BACKGROUNDS: Atrophic gastritis, especially metaplastic atrophy, has been shown to be a risk factor for gastric cancer. Some advanced endoscopic techniques have been used to diagnose atrophic gastritis. However, it is still difficult to diagnose atrophy with a high degree of accuracy. STUDY: In total, 253 gastric sites from 87 consecutive patients were examined by NBI, CE, and CLE, and in turn endoscopic diagnoses were made. Histologic diagnoses of biopsies taken from the observed sites served as gold standards. Comparisons were made of the sensitivity, specificity, and accuracy between each endoscopic technique for obtaining a diagnosis atrophic gastritis. RESULTS: NBI was found to be equivalent to CE in classifying gastric pits (κ=0.904). The CLE had a higher sensitivity (P=0.035), specificity (P=0.049), and accuracy (P=0.002) than CE for diagnosing atrophic gastritis. The sensitivity and specificity of CLE for diagnosing nonmetaplastic atrophy were 86.76% and 91.89%, respectively, and for metaplastic atrophy were 91.94% and 96.86%, respectively. Interobserver and intraobserver agreements of CLE for predicting histopathologic gastritis were both high (0.938 and 0.895, respectively). CONCLUSIONS: CLE is reliable for real-time assessment of atrophic gastritis and is also able to differentiate metaplastic from nonmetaplastic atrophy.

STK11 domain XI mutations: candidate genetic drivers leading to the development of dysplastic polyps in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is a rare hereditary disorder resulting from mutations in serine/threonine kinase 11 (STK11) and characterized by gastrointestinal (GI) hamartomatous polyps, mucocutaneous pigmentation, and an increased risk for specific cancers. Little is known about the genetic implications of specific STK11 mutations with regard to their role in dysplastic and malignant transformation of GI polyps. Peripheral blood genomic DNA samples from 116 Chinese PJS patients from 52 unrelated families were investigated for STK11 mutations. Genotype-phenotype correlations were investigated. The mutation detection rate was 67.3% (51.9% point mutations, 15.4% large deletions). Fourteen out of the 25 point mutations identified were novel. Nearly one-third of all mutations, 8/27 (29.6%), were in exon 7, the shortest out of the nine exons. Strikingly, mutations affecting protein kinase domain XI, encoded in part by exon 7, correlated with a 90% (9/10) incidence of GI polyp dysplasia. In contrast, only two out of 17 (11.8%) nondomain XI mutations were linked to polyp dysplasia (P = 0.0001). The extent of the association between dysplasia and the development of GI-related cancers is currently unknown but our results highlight a novel STK11 genotype-phenotype association as the basis for future genetic counseling and basic research studies.

miR-23a inhibits E-cadherin expression and is regulated by AP-1 and NFAT4 complex during Fas-induced EMT in gastrointestinal cancer.

Fas signaling has been shown to induce the epithelial-mesenchymal transition (EMT) to promote gastrointestinal (GI) cancer metastasis, but the involvement of microRNA in this mechanism remains unknown. We found that Fas ligand (FasL) treatment inhibited E-cadherin expression and promoted cell invasion by upregulation of miR-23a, but overexpression of the miR-23a inhibitor could partially block this activity. FasL-induced extracellular signal-regulated kinase/mitogen-activated protein kinase signaling activated the activator protein 1 (AP-1) complex and repressed glycogen synthase kinase-3ß activity, which contributed to nuclear translocation of AP-1 and nuclear factor of activated T cells (NFAT4). Nuclear accumulation and interaction of AP-1 and NFAT4 and subsequent binding to the miR-23a promoter led to increased miR-23a expression. Inhibition of Fas signaling by downregulation of the Fas receptor led to a decrease in miR-23a expression and cell invasion ability in vivo and in vitro, as well as an increase in E-cadherin. Evaluation of human GI precancerous and cancer specimens showed that the expression of FasL and miR-23a increased, whereas the expression of E-cadherin decreased during GI cancer progression. A significant correlation was noted between any two of these three molecules. An EMT phenotype was shown to correlate with an advanced cancer stage and worse prognosis. Taken together, our results show that miR-23a participates in the mechanism of the FasL-induced EMT process and may serve as a potential therapeutic target for cancer metastasis.

MYG1 drives glycolysis and colorectal cancer development through nuclear-mitochondrial collaboration.

Metabolic remodeling is a strategy for tumor survival under stress. However, the molecular mechanisms during the metabolic remodeling of colorectal cancer (CRC) remain unclear. Melanocyte proliferating gene 1 (MYG1) is a 3'-5' RNA exonuclease and plays a key role in mitochondrial functions. Here, we uncover that MYG1 expression is upregulated in CRC progression and highly expressed MYG1 promotes glycolysis and CRC progression independent of its exonuclease activity. Mechanistically, nuclear MYG1 recruits HSP90/GSK3ß complex to promote PKM2 phosphorylation, increasing its stability. PKM2 transcriptionally activates MYC and promotes MYC-medicated glycolysis. Conversely, c-Myc also transcriptionally upregulates MYG1, driving the progression of CRC. Meanwhile, mitochondrial MYG1 on the one hand inhibits oxidative phosphorylation (OXPHOS), and on the other hand blocks the release of Cyt c from mitochondria and inhibits cell apoptosis. Clinically, patients with KRAS mutation show high expression of MYG1, indicating a high level of glycolysis and a poor prognosis. Targeting MYG1 may disturb metabolic balance of CRC and serve as a potential target for the diagnosis and treatment of CRC.

Clinical manifestation, lifestyle, and treatment patterns of chronic erosive gastritis: A multicenter real-world study in China.

BACKGROUND: Although chronic erosive gastritis (CEG) is common, its clinical characteristics have not been fully elucidated. The lack of consensus regarding its treatment has resulted in varied treatment regimens. AIM: To explore the clinical characteristics, treatment patterns, and short-term outcomes in CEG patients in China. METHODS: We recruited patients with chronic non-atrophic or mild-to-moderate atrophic gastritis with erosion based on endoscopy and pathology. Patients and treating physicians completed a questionnaire regarding history, endoscopic findings, and treatment plans as well as a follow-up questionnaire to investigate changes in symptoms after 4 wk of treatment. RESULTS: Three thousand five hundred sixty-three patients from 42 centers across 24 cities in China were included. Epigastric pain (68.0%), abdominal distension (62.6%), and postprandial fullness (47.5%) were the most common presenting symptoms. Gastritis was classified as chronic non-atrophic in 69.9% of patients. Among those with erosive lesions, 72.1% of patients had lesions in the antrum, 51.0% had multiple lesions, and 67.3% had superficial flat lesions. In patients with epigastric pain, the combination of a mucosal protective agent (MPA) and proton pump inhibitor was more effective. For those with postprandial fullness, acid regurgitation, early satiety, or nausea, a MPA appeared more promising. CONCLUSION: CEG is a multifactorial disease which is common in Asian patients and has non-specific symptoms. Gastroscopy may play a major role in its detection and diagnosis. Treatment should be individualized based on symptom profile.

SOX2 promotes vasculogenic mimicry by accelerating glycolysis via the lncRNA AC005392.2-GLUT1 axis in colorectal cancer.

Vasculogenic mimicry (VM), a new model of angiogenesis, fulfills the metabolic demands of solid tumors and contributes to tumor aggressiveness. Our previous study demonstrated the effect of SOX2 in promoting VM in colorectal cancer (CRC). However, the underlying mechanisms behind this effect remain elusive. Here, we show that SOX2 overexpression enhanced glycolysis and sustained VM formation via the transcriptional activation of lncRNA AC005392.2. Suppression of either glycolysis or AC005392.2 expression curbed SOX2-driven VM formation in vivo and in vitro. Mechanistically, SOX2 combined with the promoter of AC005392.2, which decreased H3K27me3 enrichment and thus increased its transcriptional activity. Overexpression of AC005392.2 increased the stability of GLUT1 protein by enhancing its SUMOylation, leading to a decrease in the ubiquitination and degradation of GLUT1. Accumulation of GLUT1 contributed to SOX2-mediated glycolysis and VM. Additionally, clinical analyses showed that increased levels of AC005392.2, GLUT1, and EPHA2 expression were positively correlated with SOX2 and were also associated with poor prognoses in patients with CRC. Our study conclusively demonstrates that the SOX2-lncRNA AC005392.2-GLUT1 signaling axis regulates VM formation in CRC, offering a foundation for the development of new antiangiogenic drugs or new drug combination regimens.

Statin use and risk of pancreatic cancer: a meta-analysis.

PURPOSE: Statins are commonly prescribed medications that potently reduce cholesterol levels and the risk of cardiovascular events. Preclinical studies suggested statins also possess cancer chemopreventive properties. However, the clinical studies provided contradictory results as to whether statins influence the risk of pancreatic cancer. Herein, we present this meta-analysis to assess the association between statin use and risk of pancreatic cancer. METHODS: We conducted a comprehensive search up to August 2011 for the eligible studies. Pooled relative risk (RR) estimates and corresponding 95 % confidence intervals (CIs) were calculated using the inverse-variance-weighted random-effects model. Subgroup analyses were conducted where data were available. Heterogeneity was assessed by the Cochran's Q test and the I(2) statistic. RESULTS: We included 16 studies that involving 1,692,863 participants and 7,807 pancreatic cancer cases. Pooled results only indicated a non-significant decrease of pancreatic cancer risk among all statin users (RR 0.89; 95 % CIs, 0.74-1.07). Similar results were obtained in the subgroup analyses of the long-term (more than 4 years) follow-up (RR 0.94, 0.81-1.08) and statin use (RR 0.97, 0.76-1.23), and a null association was found between lipophilic statin use and pancreatic cancer risk (RR 1.03, 0.92-1.16). No evidence of publication bias was observed in the present meta-analysis. However, significant heterogeneity was detected among all studies (p < 0.00001, I(2) = 81 %). CONCLUSIONS: In conclusion, our results suggest that there is no association between statin use and pancreatic cancer risk, when statins are taken at daily doses for cardiovascular event prevention.

Ultrafast quantum random number generation based on quantum phase fluctuations.

A quantum random number generator (QRNG) can generate true randomness by exploiting the fundamental indeterminism of quantum mechanics. Most approaches to QRNG employ single-photon detection technologies and are limited in speed. Here, we experimentally demonstrate an ultrafast QRNG at a rate over 6 Gbits/s based on the quantum phase fluctuations of a laser operating near threshold. Moreover, we consider a potential adversary who has partial knowledge on the raw data and discuss how one can rigorously remove such partial knowledge with postprocessing. We quantify the quantum randomness through min-entropy by modeling our system and employ two randomness extractors--Trevisan's extractor and Toeplitz-hashing--to distill the randomness, which is information-theoretically provable. The simplicity and high-speed of our experimental setup show the feasibility of a robust, low-cost, high-speed QRNG.

Impact of Recycler Information Sharing on Supply Chain Performance of Construction and Demolition Waste Resource Utilization.

In recent years, the generation of a large amount of construction and demolition waste (CDW) has threatened the public environment and human health. The inefficient supply chain of CDW resource utilization hinders the green development of countries around the world, including China. This study aims to reveal the impact of information sharing regarding recyclers' market demand forecast on the performance of CDW resource utilization supply chains. Therefore, this paper uses the incomplete information dynamic game method to establish and solve the decision-making model of the construction and demolition waste resource utilization supply chain under the conditions of recyclers sharing and not sharing their information. The paper then obtains the Bayesian equilibrium solution and the optimal expected profit for each party. Finally, a numerical simulation was used in order to verify the validity of the model and conclusions. The main conclusions are as follows. In the CDW resource utilization supply chain, if the recycler is more pessimistic about the market's demand forecast, their information sharing makes the remanufacturer more motivated to improve their level of environmental responsibility. In addition, information sharing by recyclers is always beneficial in increasing the profit of the remanufacturer, but it also may make the recycler lose profit. When the efficiency of the environmental responsibility investment of remanufacturers is in a high range, information sharing increases the profits of recyclers. Conversely, information sharing has no significant effect on the profits of recyclers. The impact on the profits of the entire CDW resource utilization supply chain depends on the intensity of competition among channels, the market share of offline recycling channels and the efficiency of environmental responsibility investments.

A novel mutation in STK11 gene is associated with Peutz-Jeghers syndrome in Chinese patients.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is caused by mutations in the tumor suppressor gene, STK11, and is characterized by gastrointestinal hamartomas, melanin spots on the lips, and an increased risk of developing cancer. METHODS: Blood samples were collected from two unrelated Chinese PJS families totaling 20 individuals (9 male and 11 females), including 6 PJS patients. The entire coding region of the STK11 gene was amplified by polymerase chain reaction and analyzed by direct sequencing. RESULTS: A novel mutation, c.904C > T, in exon 7 was identified in both families. A C > T substitution changed codon 302 from CAG (glutamine) to TAG (stop), truncating the STK11 protein, thus leading to the partial loss of the kinase domain and complete loss of the α-helix C-terminus. Furthermore, one PJS patient from each family was diagnosed with a visceral cancer, a colon cancer and a liver cancer respectively. CONCLUSION: We predict that this novel mutation, p.Q302X, is most likely responsible for development of the PJS phenotype and may even contribute to malignancy.

The role of hedgehog signaling pathway in liver regeneration.

BACKGROUND/AIMS: In this study, we explored the role of the Hedgehog signaling pathway in liver regeneration. METHODOLOGY: Retrorsine, partial hepatectomy and combined were utilized in mature Fisher344 rats. Specific assays, such as RT-PCR, real-time PCR and immunohistochemistry were used to detect the constituents of the Hedgehog signaling pathway during liver regeneration. RESULTS: mRNA expression of Ihh, Ptc, Smo, Gli1, Gli2 and Gli3 were all shown in liver tissue homogenates in control/normal, retrorsine, partial hepatectomy and retrorsine/partial hepatectomy groups while no Shh expression was found. Real-time PCR analysis indicated that there were significant differences in Hedgehog signaling pathway-related constituents (Ihh, Ptc, Gli1 and Gli3) among the different treatment groups and at distinct time points in the same treatment group during liver regeneration. The data also suggested an interaction effect between different treatment and time to the variation of Ihh, Ptc, Gli1 and Gli3. The protein expression of Ptc and Gli1 in liver regeneration was confirmed by immunohistochemistry, which differed in the duration among different groups. Nevertheless, the protein expression of Ptc and Gli1 were not detected successfully by western blot. CONCLUSIONS: It appears that the Hedgehog signaling pathway may be involved in liver regeneration.

SOX2 promotes chemoresistance, cancer stem cells properties, and epithelial-mesenchymal transition by ß-catenin and Beclin1/autophagy signaling in colorectal cancer.

Sex-determining region Y-box2 (SOX2), a master regulator of embryonic and induced pluripotent stem cells, drives cancer stem cells (CSCs) properties, fuels tumor initiation, and contributes to tumor aggressiveness. Our previous study has demonstrated the oncogenic role of SOX2 in colorectal cancer (CRC). In this study, we sought to elucidate the underlying mechanisms. Cell function experiments were performed to detect chemoresistance, proliferation, stemness, migration, and invasion in vitro. Chromatin immunoprecipitation, co-immunoprecipitation, luciferase reporter assay, and immunofluorescence were performed to explore the regulation of ABCC2, ß-catenin, and Beclin1 by SOX2. The carcinogenic role of SOX2-ß-catenin/Beclin1-ABCC2 axis in vivo was analyzed by CRC tissues and xenograft models. Here, we reported that SOX2 sustained chemoresistance by transcriptional activation of ABCC2 expression. Suppressing either ß-catenin or autophagy signaling curbed SOX2-driven chemoresistance, stemness, and epithelial-mesenchymal transition (EMT). Mechanistically, SOX2 combined with ß-catenin and increased its nuclear expression and transcriptional activity. Transcriptional activation of Beclin1 expression by SOX2 consequently activating autophagy and inducing malignant phenotype. Furthermore, overexpression of ß-catenin or Beclin1 facilitated ABCC2 expression. The clinical analyses showed that high expression of ABCC2 and Beclin1 were positively correlated with SOX2 and were associated with poor prognosis in CRC patients. Finally, xenograft models revealed that inhibition of SOX2 expression and autophagy restrained tumor growth and chemoresistance in vivo. Conclusively, we demonstrated a novel mechanism by which the SOX2-ß-catenin/Beclin1/autophagy signaling axis regulates chemoresistance, stemness, and EMT in CRC. Our findings provide novel insights into CRC carcinogenesis and may help develop potential therapeutic candidates for CRC.

Comparison of physical electrical conductivity and acupuncture de-qi sensation between stainless steel needling and supercritical fluid-treated needling.

BACKGROUND: While acupuncture has been used for thousands of years, modern technology to develop new needle materials has rarely been discussed. We aim to explore a new acupuncture needle material and compare the differences in the needling sensations between the acupuncture needle surface treated with nitrogen applied supercritical fluid (SCF-N) and conventional stainless steel needles. METHODS: This was a double-blind cohort study. The acupuncture needles were randomly used in this experiment, including the SCF-N-treated needles and the control stainless steel needles. LI 4 (Hegu) and LI 11 (Quchi) acupuncture points in the Yangming Large Intestine Meridian of Hand were treated. Physical electrical resistance, scanning electron microscopy, energy dispersive spectrometry, and visual analog scale (VAS) score including the sensations of soreness, numbness, distention, and heaviness were assessed. RESULTS: The proportion of nitrogen (N) was significantly higher in the SCF-N-treated needles than in the stainless steel needles group (2.3 ± 0.2% vs 0.0 ± 0.0%, P < 0.01). The cumulative de-qi sensation score at the LI 4 Hegu acupoint (1.87 ± 1.88 vs 1.54 ± 1.62, P = 0.014), especially the sensation of soreness score (2.76 ± 2.06 vs 2.13 ± 1.85, P = 0.045), revealed statistically significant differences between both groups. SCF-N surface treatment of acupuncture needles may lower the electrical resistance more than the control stainless steel needles (24.67 ± 0.88 kW vs 26.45 ± 0.75 kW, p < 0.01). CONCLUSION: Acupuncture needles modified with SCF-N surface treatment can enhance de-qi sensations to improve electrical conductivity of the meridian and therapeutic effects on the Yangming Large Intestine Meridian of Hand. SCF-N surface treated needles can be as a new acupuncture needle material in the future.

Regulation of cancer stem cell properties, angiogenesis, and vasculogenic mimicry by miR-450a-5p/SOX2 axis in colorectal cancer.

Growing evidence indicates that a small number of cancer cells express stem cell markers and possess stem cell-like properties that promote malignant progression. Sex-determining region Y-box2 (SOX2) is a stem cell transcription factor essential for maintaining the properties of cancer stem cell (CSC). As CSC properties have been associated with angiogenesis and vasculogenic mimicry (VM), we aimed to comprehensively investigate whether SOX2 regulates CSC properties, angiogenesis, and VM in colorectal carcinoma (CRC) and its potential mechanism in this study. For this study, sphere formation assay, flow cytometry, cell survival analysis, tube formation, 3D culture, immunoblot, mouse model, and luciferase reporter assay were performed in vivo and in vitro. Expressions of SOX2 and miR-450a-5p in CRC tissue samples were examined through immunohistochemistry. First, the expression of SOX2 was not only associated with poor differentiation and prognosis but also promoted angiogenesis and VM. Knockdown of SOX2 ceased stemness properties, angiogenesis, and VM, along with decreased expression of CD133, CD31, and VE-cadherin as observed in functional experiments. Downregulation of SOX2 was found to inhibit tumorigenesis in vivo. Second, miR-450a-5p suppressed the expression of SOX2 by targeting its 3'UTR region directly and hence restrained SOX2-induced CSC properties, angiogenesis, and VM. Moreover, SOX2 overexpression preserved the miR-450a-5p-induced inhibition of CRC properties, angiogenesis, and VM. Finally, clinical samples exhibited a negative correlation between miR-450a-5p and SOX2. Patients with higher SOX2 and lower miR-450a-5p expressions had a poorer prognosis than patients with inverse expressions. Conclusively, we elucidated a unique mechanism of miR-450a-5p-SOX2 axis in the regulation of stemness, angiogenesis, and VM, which may act as a potential therapeutic practice in CRC.

Meridian study on the response current affected by electrical pulse and acupuncture.

Acupuncture and its meridians are important components of traditional Chinese medicine, and numerous opinions have been previously expressed regarding these meridians. This study aims to explore the phenomenon of meridians from the perspective of electronic physics by studying these meridians for the response current affected by electrical pulse and acupuncture. In this study, acupuncture which applies an electrical pulse was used to research the physical properties of the meridians. Different kinds of pulses were applied to the human body to realize abnormal electrical signals. Comparing these electrical measurement results with the isothermal transient ionic current (ITIC) theory, we found that the transmission of meridian messages may be related to ion conduction. The movement of ions induced by acupuncture and electrical stimulation can lead to drift and diffusion currents through the meridians. The ionic conduction of meridian hypothesis is proved in that the substances delivered by meridians are in fact ions.

Investigation of virulence genes in clinical isolates of Yersinia enterocolitica.

In this study, we aimed to investigate the distribution of virulence genes in clinical isolates of pathogenic Yersinia enterocolitica. Two thousand six hundred stool samples were collected from 2600 patients with diarrhea, and were tested using the culture method and real-time PCR. Then, all isolates of pathogenic Y. enterocolitica cultured from the culture method were examined for virulence genes (inv, ail, ystA, ystB, ystC, yadA, virF) by PCR and for the presence of plasmid by four phenotypic tests. As a result, 160 pathogenic strains were successfully detected by the culture method, including bio/serotype 1A/unknown (4), 1B/unknown (8), 2/O:9 (39), 2/unknown (7), 3/O:3 (22), 3/unknown (6), 4/O:3 (55), 4/unknown (10) and 5/unknown (9). The positive rate of virulence genes tested in 160 isolates was inv (100%), ail (94%), ystA (93%), ystB (7.5%), ystC (5%), yadA (89%) and virF (82%) while the phenotypic test included autoagglutination (87%), binding of crystal violet (89%), calcium-dependent growth (74%) and Congo red absorption (78%), respectively. Finally, we found that not all pathogenic Y. enterocolitica necessarily carry all traditional virulence genes in both chromosomes and plasmids to cause illness. Perhaps, some of them, lacking some traditional virulence genes, contain other unknown virulence markers that interact with each other and play an important role in the diverse pathogenesis of pathogenic Y. enterocolitica.

DNA microarray for direct identification of bacterial pathogens in human stool samples.

AIM: To establish and evaluate a quick and accurate DNA microarray method to detect intestinal pathogens directly from human diarrheal stool samples as an alternative to traditional culture methods. METHOD: Primers and 21 oligonucleotide probes based on sequences of the bacterial 16SrRNA gene were arrayed on microarray slides. Hybridization between probes and amplicons was performed. To determine the consistency of DNA microarray and culture method, 1,500 samples of clinical diarrheal stool and 200 samples of normal stool from healthy individuals were examined in a double-blind fashion. Basic information from patients was collected and analyzed. RESULT: Our data showed that the probes of the assay were successful in discriminating 14 genera or species of intestinal pathogens. The limit of detection was approximately 10(3) CFU/ml for one species of pathogen. Of the 1,500 clinical cases, 32.7% of the patient stools were positive for bacteria. Using stool culture as a control, gene-chip sensitivity was 100%, specificity 95.2%, and index of accurate diagnosis 0.952. CONCLUSION: Our data suggested that DNA microarray with its high efficiency and accuracy could be used as an alternative to the culture method.

Two novel STK11 missense mutations induce phosphorylation of S6K and promote cell proliferation in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is a rare hereditary disease caused by mutations in serine threonine kinase 11 (STK11) and characterized by an increased risk of developing cancer. Inactivation of STK11 has been associated with the mammalian target of rapamycin (mTOR) pathway. Hyperactivation and phosphorylation of the key downstream target genes ribosomal protein S6 kinase 1 (S6K1) and S6 promote protein synthesis and cell proliferation. To better understand the effects of STK11 dysfunction in the pathogenesis of PJS, genomic DNA samples from 21 patients with PJS from 11 unrelated families were investigated for STK11 mutations in the present study. The results revealed 6 point mutations and 2 large deletions in 8 (72.7%, 8/11) of the unrelated families. Notably, 3 novel mutations were identified, which included 2 missense mutations [c.88G>A (p.Asp30Asn) and c.869T>C (p.Leu290Pro)]. Subsequent immunohistochemical analysis revealed staining for phosphorylated-S6 protein in colonic hamartoma and breast benign tumor tissues from patients with PJS carrying the two respective missense mutations. Additionally, the novel missense STK11 mutants induced phosphorylation of S6K1 and S6, determined using western blot analysis, and promoted the proliferation of HeLa and SW1116 cells, determined using Cell Counting Kit-8 and colony formation assays. Collectively, these findings extend the STK11 mutation spectrum and confirm the pathogenicity of two novel missense mutations. This study represents a valuable insight into the molecular mechanisms implicated in the pathogenesis of PJS.