[Pancreas multidisciplinary team optimizes the diagnosis and treatment of pancreas-related diseases and improves the prognosis of pancreatic cancer patients].

Objectives: To evaluate the role of pancreas multidisciplinary team(MDT) clinic in the diagnosis of pancreatic diseases,patient compliance with MDT advice,and the impact of MDT on the postoperative survival of patients with pancreatic cancer. Methods: The study included 927 patients(554 males,373 females,aged (58.1±13.3)years (range: 15 to 89 years)) that had visited the pancreas MDT clinic of Zhongshan Hospital from May 2015 to December 2021,and 677 patients(396 males, 281 females, aged (63.6±8.9)years(range: 32 to 95 years)) who underwent radical surgery and with pathologically confirmed pancreatic adenocarcinoma from January 2012 to December 2020,of whom 79 patients had attended the pancreas MDT. The clinical and pathological data were collected and analyzed retrospectively. Diseases were classified in accordance with 2010 WHO classification of tumors of the digestive system and usual clinical practices. The Kaplan-Meier method was used for drawing the survival curve and calculating the survival rate. The univariate analysis was done by Log-rank test and the multivariate analysis was done by COX proportional hazards model. Survival rates were compared using χ2 test. Results: Among the 927 patients that had visited the MDT clinic,233 patients(25.1%) were referred due to undetermined diagnosis. A direct diagnosis was made in 109 cases (46.8%,109/233) by the MDT clinic, of which 98 were consistent with the final diagnosis,resulting in an accuracy of 89.9%(98/109). The direct diagnosis rate in the recent years(36.6%(41/112),from June 2019 to December 2021) decreased compared to that in the previous years(56.2%(68/121),from May 2015 to May 2019),yet the accuracy in the recent years(90.2%,37/41) was basically the same as before (89.7%,61/68). The rate of compliance of the entire cohort was 71.5%(663/927), with the compliance rate in the recent two and a half years(81.4%,338/415) remarkably higher than that in the previous four years(63.4%,325/512). Patients with pancreatic cancer that attended the MDT exhibited a trend toward longer median postoperative survival than patients that did not attend the MDT,but the difference was not statistically significant(35.2 months vs.30.2 months,P>0.05). The 1-year and 3-year survival rates of patients that attended the MDT were significanly higher than patients that did not attend the MDT(88.6% vs. 78.4%,P<0.05;32.9% vs. 21.9%,P<0.05,respectively),but the 5-year survival rate was not statistically different(7.6% vs. 4.8%,P>0.05). Conclusions: The pancreas MDT clinic is an accurate and convenient way to diagnose intractable pancreatic diseases,and in the recent years the patients' compliance rate with MDT advice has increased. Pancreatic cancer patients that have attended the MDT have higher 1-year and 3-year postoperative survival rates,but the long-term survival benefits of MDT still needs to be proved by clinical studies on a larger scale.

Integrating Functional Analysis in the Next-Generation Sequencing Diagnostic Pipeline of RASopathies.

RASopathies are a group of heterogeneous conditions caused by germline mutations in RAS/MAPK signalling pathway genes. With next-generation sequencing (NGS), sequencing capacity is no longer a limitation to molecular diagnosis. Instead, the rising number of variants of unknown significance (VUSs) poses challenges to clinical interpretation and genetic counselling. We investigated the potential of an integrated pipeline combining NGS and the functional assessment of variants for the diagnosis of RASopathies. We included 63 Chinese patients with RASopathies that had previously tested negative for PTPN11 and HRAS mutations. In these patients, we performed a genetic analysis of genes associated with RASopathies using a multigene NGS panel and Sanger sequencing. For the VUSs, we evaluated evidence from genetic, bioinformatic and functional data. Twenty disease-causing mutations were identified in the 63 patients, providing a primary diagnostic yield of 31.7%. Four VUSs were identified in five patients. The functional assessment supported the pathogenicity of the RAF1 and RIT1 VUSs, while the significance of two VUSs in A2ML1 remained unclear. In summary, functional analysis improved the diagnostic yield from 31.7% to 36.5%. Although technically demanding and time-consuming, a functional genetic diagnostic analysis can ease the clinical translation of these findings to aid bedside interpretation.

[Study on the disease burden of Chinese adolescent in 2015].

Objective: To discuss the main causes and risk factors of disability and death among current Chinese adolescents. Methods: Subnational data of China from Global Burden of Disease Study 2015 (GBD 2015) was used to rank the causes and risk factors leading to death and disability adjusted life years (DALY) in Chinese adolescents aged between 10 and 19 years old, and thereby to analyze the main cauese and risk factors of death and DALY among Chinese adolescents in different genders. Results: In 2015, among Chinese adolescents aged 10-19 years old, the total DALY was 13 million 490 thousand years, and the total number of deaths was 63 258 cases. The top 3 causes of DALY were skin and subcutaneous diseases, iron-deficiency anemia and road injuries, resulting in DALY (constituent ratio) of 1 411 (10.5%), 1 094 (8.1%) and 1 029 (7.6%) thousand years respectively. The top 3 causes of death were road injuries, drowning and leukemia, causing 13 881 (21.9%), 9 895 (15.6%) and 4 620 (7.3%) deaths (constituent ratio) respectively. The top 3 risk factors of DALY were iron deficiency, alcohol use and drug use, causing 1 094 (8.1%), 487 (3.6%) and 220 thousand years (1.6%) DALY (constituent ratio) respectively. The top 3 risk factors of death were alcohol use, occupational injuries and drug use, causing 5 957 (9.4%), 1 523 (2.4%) and 810 (1.3%) deaths respectively. Conclusion: Unintentional injury was the top cause of DALY and death in Chinese adolescents, followed by skin and subcutaneous diseases and iron-deficiency anemia. Iron deficiency and alcohol use were the top two risk factors of DALY and death.

Evaluation of warfarin resistance using transcription activator-like effector nucleases-mediated vitamin K epoxide reductase knockout HEK293 cells.

BACKGROUND: Single nucleotide polymorphisms in the vitamin K epoxide reductase (VKOR) gene have been successfully used for warfarin dosage prediction. However, warfarin resistance studies of naturally occurring VKOR mutants do not correlate with their clinical phenotype. This discrepancy presumably arises because the in vitro VKOR activity assay is performed under artificial conditions using the non-physiological reductant dithiothreitol. OBJECTIVES: The aim of this study is to establish an in vivo VKOR activity assay in mammalian cells (HEK293) where VKOR functions in its native milieu without interference from endogenous enzymes. METHODS: Endogenous VKOR activity in HEK293 cells was knocked out by transcription activator-like effector nucleases (TALENs)-mediated genome editing. RESULTS AND CONCLUSIONS: Knockout of VKOR in HEK293 cells significantly decreased vitamin K-dependent carboxylation with vitamin K epoxide (KO) as substrate. However, the paralog of VKOR, VKORC1L1, also exhibits substantial ability to convert KO to vitamin K for carboxylation. Using both VKOR and VKORC1L1 knockout cells, we examined the enzymatic activity and warfarin resistance of 10 naturally occurring VKOR mutants that were reported previously to have no activity in an in vitro assay. All 10 mutants are fully active; five have increased warfarin resistance, with the order being W59R>L128R≈W59L>N77S≈S52L. Except for the L128R mutant, this order is consistent with the clinical anticoagulant dosages. The other five VKOR mutants do not change VKOR's warfarin sensitivity, suggesting that factors other than VKOR play important roles. In addition, we confirmed that the conserved loop cysteines in VKOR are not required for active site regeneration after each cycle of oxidation.

Epigenetic inactivation of the miR-34a in hematological malignancies.

miR-34a is a transcriptional target of p53 and implicated in carcinogenesis. We studied the role of miR-34a methylation in a panel of hematological malignancies including acute leukemia [acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL)], chronic leukemia [chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML)], multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL). The methylation status of miR-34a promoter was studied in 12 cell lines and 188 diagnostic samples by methylation-specific polymerase chain reaction. miR-34a promoter was unmethylated in normal controls but methylated in 75% lymphoma and 37% myeloma cell lines. Hypomethylating treatment led to re-expression of pri-miR-34a transcript in lymphoma cells with homozygous miR-34a methylation. In primary samples at diagnosis, miR-34a methylation was detected in 4% CLL, 5.5% MM samples and 18.8% of NHL at diagnosis but none of ALL, AML and CML (P = 0.011). In MM patients with paired samples, miR-34a methylation status remained unchanged at progression. Amongst lymphoid malignancies, miR-34a was preferentially methylated in NHL (P = 0.018), in particular natural killer (NK)/T-cell lymphoma. In conclusion, amongst hematological malignancies, miR-34a methylation is preferentially hypermethylated in NHL, in particular NK/T-cell lymphoma, in a tumor-specific manner, therefore the role of miR-34a in lymphomagenesis warrants further study.

Roles of spike protein in the pathogenesis of SARS coronavirus.

1. Infection with SARS coronavirus (SARS-CoV) induces a cellular stress condition known as the unfolded protein response (UPR). UPR induction is mediated primarily by viral spike (S) protein. The modulation of UPR by S protein involves activation of PERK protein kinase. Other branches of the UPR pathways controlled by IRE1 and ATF6 proteins, respectively, are not involved. 2. The protease inhibitor Ben-HCl effectively suppresses SARS-CoV infection by blocking virus entry. Viral infectivity is associated with the cleavage of S protein by the cellular protease factor Xa. 3. Two new aspects of the interaction between SARS-CoV S protein and the cell have been defined. These have important implications in the pathogenesis of SARS, providing opportunities for developing vaccines and antivirals against SARS-CoV. 4. Counteracting the UPR and targeting the cleavage of S protein with small molecule pharmaceutical agents represent two new anti-SARS-CoV strategies. 5. The receptor-binding domain of S protein delivered via adeno-associated virus can efficiently induce mucosal immunity and provide long-term protection against SARS-CoV infection.

Hepatocyte-specific activation of NF-kappaB does not aggravate chemical hepatocarcinogenesis in transgenic mice.

The NF-kappaB signalling pathway plays important roles in liver organogenesis and carcinogenesis. Mouse embryos deficient in IKKbeta die in mid-gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF-kappaB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF-kappaB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKbeta was expressed in a hepatocyte-specific manner. Using electrophoretic mobility shift assay, we documented increased NF-kappaB activities and up-regulated levels of NF-kappaB downstream target genes, Bcl-xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF-kappaB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild-type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF-kappaB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF-kappaB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF-kappaB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases.

Utility of Epstein-Barr virus-encoded small RNA promoters for driving the expression of fusion transcripts harboring short hairpin RNAs.

To induce RNA interference (RNAi), either small interfering RNAs (siRNAs) are directly introduced into the cell or short hairpin RNAs (shRNAs) are expressed from a DNA vector. At present, shRNAs are commonly synthesized by RNA polymerase III (Pol III) promoters of the H1 and U6 RNAs. In this study, we designed and characterized a new set of plasmid vectors driven by promoters of the Epstein-Barr virus (EBV)-encoded small RNAs (EBERs). The EBERs are the most abundant transcript in infected cells and they are transcribed by Pol III. We showed that the EBER promoters were able to drive the expression of shRNA fusion transcripts. siRNAs processed from these fusion transcripts specifically and effectively inhibited the expression of homologous reporter or endogenous genes in various types of cells. The partial EBER sequences in the fusion transcripts did not activate double-stranded RNA-dependent protein kinase or suppress RNAi. In nasopharyngeal carcinoma cells, the EBER2 promoter was stronger than the H1 and U6 promoters in shRNA synthesis, leading to more effective knockdown of the target genes. Taken together, our findings suggest that the EBER promoters fundamentally different from those of H1 and U6 can be used to drive the intracellular expression of shRNAs for effective silencing of target genes in mammalian cells and particularly, in EBV-infected cells.

Transgene expression levels and kinetics determine risk of humoral immune response modeled in factor IX knockout and missense mutant mice.

Immune responses leading to antibody-mediated elimination of the transgenic protein are a concern in gene replacement for congenital protein deficiencies, for which hemophilia is an important model. Although most hemophilia B patients have circulating non-functional but immunologically crossreactive factor IX (FIX) protein (CRM+ phenotype), inciting factors for FIX neutralizing antibody (inhibitor) development have been studied in crossreactive material-negative (CRM-) animal models. For this study, determinants of FIX inhibitor development were compared in hemophilia B mice, in which circulating FIX protein is absent (CRM- factor IX knockout (FIXKO) model) or present (CRM+ missense R333Q-hFIX model) modeling multiple potential therapies. The investigations compare for the first time different serotypes of adeno-associated virus (AAV) vectors (AAV2 and AAV1), each at multiple doses, in the setting of two different FIX mutations. The comparisons demonstrate in the FIXKO background (CRM- phenotype) that neither vector serotype nor vector particle number independently determine the inhibitor trigger, which is influenced primarily by the level and kinetics of transgene expression. In the CRM+ missense background, inhibitor development was never stimulated by AAV gene therapy or protein therapy, despite the persistence of lymphocytes capable of responding to FIX with non-inhibitory antibodies. This genotype/phenotype is strongly protective against antibody formation in response to FIX therapy.

Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells.

Epstein-Barr virus (EBV) infection is closely associated with nasopharyngeal carcinoma (NPC) and can be detected in early premalignant lesions of nasopharyngeal epithelium. The latent membrane protein 1 (LMP1) is an oncoprotein encoded by the EBV and is believed to play a role in transforming premalignant nasopharyngeal epithelial cells into cancer cells. RASSF1A is a tumor-suppressor gene commonly inactivated in many types of human cancer including NPC. In this study, we report a novel function of LMP1, in down-regulating RASSF1A expression in human epithelial cells. Downregulation of RASSF1A expression by LMP1 is dependent on the activation of intracellular signaling of NF-kappaB involving the C-terminal activating regions (CTARs) of LMP1. LMP1 expression also suppresses the transcriptional activity of the RASSF1A core promoter. RASSF1A stabilizes microtubules and regulates mitotic events. Aberrant mitotic spindles and chromosome aberrations are reported phenotypes in RASSF1A inactivated cells. In this study, we observed that LMP1 expression in human epithelial cells could induce aberrant mitotic spindles, disorganized interphase microtubules and aneuploidy. LMP1 expression could also suppress microtubule dynamics as exemplified by tracking movements of the growing tips of microtubules in live cells by transfecting EGFP-tagged EB1 into cells. The aberrant mitotic spindles and interphase microtubule organization induced by LMP1 could be rescued by transfecting RASSF1A expression plasmid into cells. Downregulation of RASSF1A expression by LMP1 may facilitate its role in transformation of premalignant nasopharyngeal epithelial cells into cancer cells.

Pancreatic adenocarcinoma: signs of vascular invasion determined by multi-detector row CT.

The purpose of this study was to analyse multi-detector row CT (MDCT) signs of peripancreatic arterial and venous invasion in pancreatic carcinoma. Among 101 patients with pancreatic carcinoma examined by MDCT, 54 candidates for surgery were pre-operatively evaluated for vascular invasion based on MDCT signs. The peripancreatic major vessels (including superior mesenteric artery, coeliac artery, common hepatic artery, superior mesenteric vein and portal vein) were examined carefully by surgeons during the operation. At surgical exploration, 78 of 224 vessels were invaded by tumour. The invaded peripancreatic major arteries (n = 29) and veins (n = 49) presented different MDCT signs: 43% of invaded veins (18/42, except for 7 occluded veins) were surrounded by tumour less than 50% of the vessel circumference compared with 97% (28/29) of the invaded arteries, which were surrounded by tumour more than 50% of the vessel circumference or were embedded in tumour (p<0.001). 69% (34/49) of the invaded veins had vascular stenosis or obliteration, compared with 41% (12/29) of the invaded arteries (p<0.05). Irregularity of the vein wall, 74% (31/42, except for 7 occluded veins); occurred more often than that of the artery wall, 45% (13/29) (p<0.05). In conclusion, the MDCT signs of peripancreatic arterial and venous invasion have different characteristics, which should be considered in pre-operative evaluation.

Epstein-Barr virus latent membrane protein 1 (LMP1) upregulates Id1 expression in nasopharyngeal epithelial cells.

Nasopharyngeal carcinoma is closely associated with Epstein-Barr virus (EBV) infection. The EBV-encoded LMP1 has cell transformation property. It suppresses cellular senescence and enhances cell survival in various cell types. Many of the downstream events of LMP1 expression are mediated through its ability to activate NF-kappaB. In this study, we report a novel function of LMP1 to induce Id1 expression in nasopharyngeal epithelial cells (NP69) and human embryonal kidney cells (HEK293). The Id1 is a basic helix-loop-helix (bHLH) protein and a negative transcriptional regulator of p16(INK4a). Expression of Id1 facilitates cellular immortalization and stimulates cell proliferation. With the combination of both specific chemical inhibitors and genetic inhibitors of cell signaling, we showed that induction of Id1 by LMP1 was dependent on its NF-kappaB activation domain at the carboxy-terminal region, CTAR1 and CTAR2. Induction of Id1 by LMP1 may facilitate clonal expansion of premalignant nasopharyngeal epithelial cells infected with EBV and may promote their malignant transformation.

Identification of a gene encoding a typical gamma-carboxyglutamic acid domain in the tunicate Halocynthia roretzi.

We report the identification of a gene capable of encoding a novel Gla (gamma-carboxyglutamic acid) protein from the tunicate Halocynthia roretzi, a primitive member of the phylum Chordata. We call this new hypothetical protein Gla-RTK; it has a Gla domain typical of human vitamin K-dependent coagulation factors, a transmembrane domain, and a receptor tyrosine kinase domain. The receptor tyrosine kinase domain is very similar to the ARK (adhesion-related kinase) family of receptor tyrosine kinases. The ARK family includes Axl, Tyro3, and c-Mer. This gene also encodes a propeptide that binds to the human gamma-glutamyl carboxylase within a range of affinities observed for mammalian propeptides. The cDNA for this putative protein is found distributed throughout the oocyte and embryo but the cDNA is apparently not transcribed except during oogenesis. One of the most interesting aspects of this hypothetical protein is that its Gla domain is highly homologous to the Gla domain of Gas6, a ligand for Axl, while its receptor tyrosine kinase domain is highly homologous to Axl.

A novel fluorescence assay to study propeptide interaction with gamma-glutamyl carboxylase.

The vitamin K-dependent gamma-glutamyl carboxylase catalyzes the posttranslational modification of select glutamate residues of its vitamin K-dependent substrates to gamma-carboxyglutamate. In this report, we describe a new fluorescence assay that is sensitive and specific for the propeptide binding site of active carboxylase. We employed the assay to make three important observations: (1) A tight binding fluorescein-labeled consensus propeptide can be used to quantify the active fraction of the enzyme. (2) The off-rate for a fluorescein-labeled factor IX propeptide was 3000-fold slower than the rate of carboxylation, a difference that may explain how carboxylase can carry out multiple carboxylations of a substrate during the same binding event. (3) We show evidence that substrate binding to the active site modifies the propeptide binding site of carboxylase. The significant (9-fold) differences in off-rates for the propeptide in the presence and absence of its co-substrates may represent a release mechanism for macromolecular substrates from the enzyme. Additionally, sedimentation velocity and equilibrium experiments indicate a monomeric association of enzyme with propeptide. Furthermore, the carboxylase preparation is monodisperse in the buffer used for our studies.

Inhibition of LZIP-mediated transcription through direct interaction with a novel host cell factor-like protein.

Host cell factor 1 (HCF-1) is a cellular transcriptional coactivator which coordinates the assembly of enhancer complex through direct interactions with viral and cellular trans-activators such as VP16, Oct-1, LZIP, and GA-binding protein. These interactions are mediated by the beta-propeller domain comprising the first 380 residues of HCF-1 with six kelch repeats. Here we describe the identification and characterization of a novel HCF-like kelch repeat protein, designated HCLP-1. HCLP-1 is a ubiquitously expressed nuclear protein which is composed almost entirely of a six-bladed beta-propeller. HCLP-1 selectively interacts with LZIP but not with VP16. The physical interaction between HCLP-1 and LZIP leads to the repression of the LZIP-dependent transcription. The HCLP-1-binding domain of LZIP maps to residues 109-315, which contain the bZIP DNA-binding motif. Electrophoretic mobility shift assay demonstrates that HCLP-1 indeed interferes with the binding of LZIP to its DNA target. Thus, HCLP-1 serves a transcriptional co-repressor function mediated through its inhibitory interaction with the LZIP transcription factor. Our findings suggest a new mechanism for transcriptional regulation by HCF-like proteins.

Effect of p53 on centrosome amplification in prostate cancer cells.

Chromosomal instability (CIN) is one of the common features in prostate cancer, especially in advanced stages. Recently, the involvement of p53 in CIN through the regulation of centrosome amplification has been proposed in certain tumor types. In this study, we investigated the relationship between p53 and centrosome amplification in prostate cancer cells. Increased centrosome number and size were observed in DU145 and PC3 containing nonfunctional p53 compared to LNCap which expressed wild-type p53. Transfection of p53 into PC3 cells resulted in a decreased cell growth rate, G2/M arrest and decreased centrosome abnormalities. We provide the first evidence on a correlation between loss of p53 function and centrosome amplification in prostate cancer cells. Our results indicate that p53 may play a role in the regulation of centrosome amplification and loss of p53 may be one of the mechanisms involving CIN in prostate cancer cells.

Genetic evidence of a role for ATM in functional interaction between human T-cell leukemia virus type 1 Tax and p53.

Recent evidence from several investigators suggest that the human T-cell leukemia virus type 1 Tax oncoprotein represses the transcriptional activity of the tumor suppressor protein, p53. An examination of published findings reveals serious controversy as to the mechanism(s) utilized by Tax to inhibit p53 activity and whether the same mechanism is used by Tax in adherent and suspension cells. Here, we have investigated Tax-p53 interaction simultaneously in adherent epithelial (HeLa and Saos) and suspension T-lymphocyte (Jurkat) cells. Our results indicate that Tax activity through the CREB/CREB-binding protein (CBP), but not NF-kappaB, pathway is needed to repress the transcriptional activity of p53 in all tested cell lines. However, we did find that while CBP binding by Tax is necessary, it is not sufficient for inhibiting p53 function. Based on knockout cell studies, we correlated a strong genetic requirement for the ATM, but not protein kinase-dependent DNA, protein in conferring a Tax-p53-repressive phenotype.