The Cellular Protein Complex Associated with a Transforming Region of E1A Contains c-MYC.

UNLABELLED: The cell-transforming activity of human adenovirus 5 (hAd5) E1A is mediated by the N-terminal half of E1A, which interacts with three different major cellular protein complexes, p300/CBP, TRRAP/p400, and pRb family members. Among these protein interactions, the interaction of pRb family proteins with conserved region 2 (CR2) of E1A is known to promote cell proliferation by deregulating the activities of E2F family transcription factors. The functional consequences of interaction with the other two protein complexes in regulating the transforming activity of E1A are not well defined. Here, we report that the E1A N-terminal region also interacted with the cellular proto-oncoprotein c-MYC and the homolog of enhancer of yellow 2 (ENY2). Our results suggested that these proteins interacted with an essential E1A transforming domain spanning amino acid residues 26 to 35 which also interacted with TRRAP and p400. Small interfering RNA (siRNA)-mediated depletion of TRRAP reduced c-MYC interaction with E1A, while p400 depletion did not. In contrast, depletion of TRRAP enhanced ENY2 interaction with E1A, suggesting that ENY2 and TRRAP may interact with E1A in a competitive manner. The same E1A region additionally interacted with the constituents of a deubiquitinase complex consisting of USP22, ATXN7, and ATXN7L3 via TRRAP. Acute short hairpin RNA (shRNA)-mediated depletion of c-MYC reduced the E1A transforming activity, while depletion of ENY2 and MAX did not. These results suggested that the association of c-MYC with E1A may, at least partially, play a role in the E1A transformation activity, independently of MAX. IMPORTANCE: The transforming region of adenovirus E1A consists of three short modules which complex with different cellular protein complexes. The mechanism by which one of the transforming modules, CR2, promotes cell proliferation, through inactivating the activities of the pRb family proteins, is better understood than the activities of the other domains. Our analysis of the E1A proteome revealed the presence of the proto-oncoprotein c-MYC and of ENY2. We mapped these interactions to a critical transforming module of E1A that was previously known to interact with the scaffolding molecule TRRAP and the E1A-binding protein p400. We showed that c-MYC interacted with E1A through TRRAP, while ENY2 interacted with it independently. The data reported here indicated that depletion of c-MYC in normal human cells reduced the transforming activity of E1A. Our result raises a novel paradigm in oncogenic transformation by a DNA viral oncogene, the E1A gene, that may exploit the activity of a cellular oncogene, the c-MYC gene, in addition to inactivation of the tumor suppressors, such as pRb.

[Clinical Value of Prophylactic Salpingectomy in Hysterectomy due to Uterine Benign Lesions].

OBJECTIVES: To explore the clinical value of resection of bilateral fallopian tubes in patients with benign uterine diseases who received (laparoscopic) hysterectomy or subhysterectomy through the postoperative pathologic analysis of resected fallopian tubes. METHODS: A retrospective analysis was conducted to review the histopathological examination results in 1 272 women who underwent (laparoscopic) total hysterectomy or subtotal hysterectomy and the removal of bilateral fallopian tube simultaneously due to uterine leiomyoma, adenomyosis and other benign lesions from December 2010 to December 2015. RESULTS: Of the 1 272 patients, laparoscopic resection was underwent in 1 005 patients (79.01%) and laparotomy in 267 patients (20.99%). In the attachment area, 334 patients (26.26%) had tenderness signs, and 401 patients (31.53%) had signs of thickening. Total 2 498 fallopian tubes were removed. There were 1 654 tubal with no obvious abnormal appearance (66.21%), 636 tubal with lumen part of the uplift (25.46%), 128 fallopian tube with congestion and swelling (5.12%), 80 fallopian tube atrophy adhesions (3.20%). Pathological. RESULTS: showed 2 386 (95.52%) fallopian tubes with chronic fallopian tube inflammation, 988 (39.55%) of fallopian tube cyst, 80 (3.20%) of normal fallopian tube, 78 (3.12%) of tubal effusion, 48 (1.92% ) of tubal hyperplasia, 4 (0.26%) of tubal benign tumor, 8 (0.32%) of tubal mucosa atypical hyperplasia change and 2(0.08%) of tubal cancer. In the 10 cases of fallopian tube cancer and atypical hyperplasia, 8 had obvious changes of chronic inflammation in the contralateral fallopian tube, including 7 cases of atypical hyperplasia and 1 case of fallopian tube cancer. CONCLUSION: Prophylactic salpingectomy can prevent the occurrence of tubal inflammation and removal cancer incentives.

Functional similarity between E6 proteins of cutaneous human papillomaviruses and the adenovirus E1A tumor-restraining module.

The adenovirus E1A C-terminal region restrains oncogenic transformation through interaction with three distinct cellular protein complexes that include the DYRK1A/1B/HAN11 complex. The E6 proteins of beta-human papillomaviruses (beta-HPVs) also interact with the DYRK1/HAN11 complex. A variant of HPV5 E6 frequently found in epidermodysplasia verruciformis skin lesions interacted less efficiently with DYRK1A/HAN11. The E6 variant and E7 of HPV5 efficiently coimmortalized primary epithelial cells, suggesting that naturally arising variants may contribute potential oncogenic activities of beta-HPV E6 proteins.

Adenovirus type 5 E1A and E6 proteins of low-risk cutaneous beta-human papillomaviruses suppress cell transformation through interaction with FOXK1/K2 transcription factors.

The adenovirus (Adv) oncoprotein E1A stimulates cell proliferation and inhibits differentiation. These activities are primarily linked to the N-terminal region (exon 1) of E1A, which interacts with multiple cellular protein complexes. The C terminus (exon 2) of E1A antagonizes these processes, mediated in part through interaction with C-terminal binding proteins 1 and 2 (CtBP1/2). To identify additional cellular E1A targets that are involved in the modulation of E1A C-terminus-mediated activities, we undertook tandem affinity purification of E1A-associated proteins. Through mass spectrometric analysis, we identified several known E1A-interacting proteins as well as novel E1A targets, such as the forkhead transcription factors, FOXK1/K2. We identified a Ser/Thr-containing sequence motif in E1A that mediated interaction with FOXK1/K2. We demonstrated that the E6 proteins of two beta-human papillomaviruses (HPV14 and HPV21) associated with epidermodysplasia verruciformis also interacted with FOXK1/K2 through a motif similar to that of E1A. The E1A mutants deficient in interaction with FOXK1/K2 induced enhanced cell proliferation and oncogenic transformation. The hypertransforming activity of the mutant E1A was suppressed by HPV21 E6. An E1A-E6 chimeric protein containing the Ser/Thr domain of the E6 protein in E1A interacted efficiently with FOXK1/K2 and inhibited cell transformation. Our results suggest that targeting FOXK1/K2 may be a common mechanism for certain beta-HPVs and Adv5. E1A exon 2 mutants deficient in interaction with the dual-specificity kinases DYRK1A/1B and their cofactor HAN11 also induced increased cell proliferation and transformation. Our results suggest that the E1A C-terminal region may suppress cell proliferation and oncogenic transformation through interaction with three different cellular protein complexes: FOXK1/K2, DYRK(1A/1B)/HAN11, and CtBP1/2.

Interaction of ZEB and histone deacetylase with the PLDLS-binding cleft region of monomeric C-terminal binding protein 2.

BACKGROUND: Proteins of the C-terminal binding protein (CtBP) family, CtBP1 and CtBP2 are closely related transcriptional regulators that are coded by two different gene loci in the vertebrate genomes. They perform redundant and unique functions during animal development. CtBP proteins mediate their transcriptional function through interaction with various DNA-binding repressors that contain PLDLS-like motifs and chromatin modifying enzymes, such as class I histone deacetylases (HDAC) that do not contain such motifs. The N-terminal region of CtBP1/2 forms a hydrophobic cleft and is involved in interaction with both PLDLS-containing factors and non-PLDLS factors. CtBP proteins function as dimers to mediate transcriptional repression and dimerization is modulated by specific binding to NAD/NADH. RESULTS: In this study, we have investigated the role of dimerization of CtBP2 in recruitment of PLDLS-motif cofactors and non-PLDLS cofactors. Our results indicate that mutations in CtBP2 that interfere with dimerization abolish CtBP2 interaction with most cellular factors, except the PLDLS-motif factor zinc-finger E-box binding homeobox (ZEB) and the non-PLDLS factor HDAC2. Unlike most PLDLS-containing CtBP-binding proteins, ZEB contains three PLDLS-like motifs and all three contribute to the interaction with the CtBP2 monomer. Despite the ability to interact with ZEB and HDAC, the CtBP2 monomer fails to mediate ZEB-dependent transcriptional repression. The lack of repression activity of the CtBP2 monomer is correlated with the competition between ZEB and HDAC for interaction with the CtBP2 monomer. CONCLUSION: These results suggest a competition between the canonical PLDLS-motif factors such as E1A and non-PLDLS factor HDAC for interaction with CtBP. They also indicate that the affinity for the CtBP monomer may be determined by the number as well as amino acid sequence compositions of the PLDLS-like motifs. Our results are consistent with a model that the CtBP2 dimer may interact with a PLDLS-containing repressor through one monomer and recruit HDAC and other chromatin modifying enzymes through the second monomer in the CtBP2 dimer.

Synchronous occurrence of primary right ovarian endometrioid adenocarcinoma and primary left ovarian clear cell adenocarcinoma: A case report.

RATIONALE: Ovarian malignancy is associated with one of the highest rates of death among gynecological reproductive system malignancies. While progress has been made in surgical and postoperative adjuvant treatment approaches, the early atypical clinical manifestations, quick progression, and lack of the effective early screening means imply that the prognosis remains poor. Bilateral ovarian cancers are common, but different types of primary bilateral ovarian carcinomas are extremely rare. PATIENT CONCERNS: According to clinical pathologic, immunohistochemistry, and medical imaging data, a 51-year-old Chinese woman with abdominal pain was diagnosed as having right ovarian well-differentiated endometrioid adenocarcinoma with mucinous adenocarcinoma and left ovarian clear cell adenocarcinoma. DIAGNOSES: Immunohistochemistry confirmed the diagnosis of primary bilateral ovarian cancers. INTERVENTIONS: She received multimodal treatment including surgery and chemotherapy. OUTCOMES: The patient's recovery was uneventful, and she responded well to the chemotherapy. LESSONS: We speculate that the different types of primary bilateral ovarian carcinomas presented in this case may be due to different malignant transformations of the endometriotic lesions. Therefore, clinicians should pay special attention to the possible malignant transformation of endometriosis.

[Effects of Thalidomide on the Ratio of Th17 to Treg Cells in Peripheral Blood and Expression of IL-17 and IL-35 in Patients with Multiple Myeloma].

OBJECTIVE: To explore the effects of thalidomide on the ratio of Th17 to Treg cells in peripheral blood and expression of IL-17 and IL-35 in patients with multiple myeloma(MM), so as to provide reference for the clinical treatment of patients with MM. METHODS: A total of 82 MM patients treated with thalidomide from January 2014 to December 2016 were enrolled in MM group, 30 healthy subjects were selected as control (control group). The ratio of T cell subsets and Treg cells accounted for CD4+T cell were detected by flow cytometer. The levels of IL-17 and IL-35 in serum were measured by ELISA, and the differences of various indexes were compared between 2 groups. RESULTS: Compared with the control group, the ratio of Th17 cells in peripheral blood and serum levels of IL-17 of MM patients were significantly increased, the ratio of Treg cells and the level of IL-35 were significantly decreased and the ratio of Th17/Treg cells was significantly increased in the patients with multiple myeloma before treatment (P<0.05). The ratio of Th17 cells in peripheral blood and serum levels of IL-17 in patients with multiple myeloma after treatment with thalidomide were significantly lower than those before treatment, and the ratio of Treg cells and levels of IL-35 were significantly higher than those before treatment, and the ratio of Th17 / Treg cells was higher than that before treatment (P<0.05). The indexes in ineffective treatment were not significantly changed (P> 0.05). CONCLUSION: The unbanlace of Th17/Treg cell ratio and abnormality of IL-17, IL-35 levels play an important role in the progression of multiple myeloma. The anti-MM mechanism of thalidomide may relate with the regulation of Th17 / Treg cell ratio and expression levels of IL-17 and IL-35.

Identification of a panel of MYC and Tip60 co-regulated genes functioning primarily in cell cycle and DNA replication.

We recently reported that adenovirus E1A enhances MYC association with the NuA4/Tip60 histone acetyltransferase (HAT) complex to activate a panel of genes enriched for DNA replication and cell cycle. Genes from this panel are highly expressed in examined cancer cell lines when compared to normal fibroblasts. To further understand gene regulation in cancer by MYC and the NuA4 complex, we performed RNA-seq analysis of MD-MB231 breast cancer cells following knockdown of MYC or Tip60 - the HAT enzyme of the NuA4 complex. We identify here a panel of 424 genes, referred to as MYC-Tip60 co-regulated panel (MTcoR), that are dependent on both MYC and Tip60 for expression and likely co-regulated by MYC and the NuA4 complex. The MTcoR panel is most significantly enriched in genes involved in cell cycle and/or DNA replication. In contrast, genes repressed by shMYC but not by shTip60 (224 genes) have a low significance of enrichment in identifiable biological processes other than cell cycle and DNA replication. Genes repressed by shTip60 but not by shMYC (102 genes) have no significant identifiable gene enrichment. We propose that MYC cooperates with the NuA4 complex to activate the MTcoR panel of genes to promote DNA replication and cell cycle.

Adenovirus E1A TRRAP-targeting domain-mediated enhancement of MYC association with the NuA4 complex activates a panel of MYC target genes enriched for gene expression and ribosome biogenesis.

Cellular transformation by adenovirus E1A requires targeting TRRAP, a scaffold protein which helps assemble histone acetyltransferase complexes, including the NuA4 complex. We recently reported that E1A and E1A 1-80 (N-terminal 80 aa) promote association of the proto-oncogene product MYC with the NuA4 complex. The E1A N-terminal TRRAP-targeting (ET) domain is required for E1A 1-80 to interact with the NuA4 complex. We demonstrate that an ET-MYC fusion associates with the NuA4 complex more efficiently than does MYC alone. Because MYC regulates genes for multiple cellular pathways, we performed global RNA-sequence analysis of cells expressing MYC or ET-MYC, and identified a panel of genes (262) preferentially activated by ET-MYC and significantly enriched in genes involved in gene expression and ribosome biogenesis, suggesting that E1A enhances MYC association with the NuA4 complex to activate a set of MYC target genes likely involved in cellular proliferation and cellular transformation by E1A and by MYC.

Enhanced MYC association with the NuA4 histone acetyltransferase complex mediated by the adenovirus E1A N-terminal domain activates a subset of MYC target genes highly expressed in cancer cells.

The proto-oncogene MYC is a transcription factor over-expressed in many cancers and required for cell survival. Its function is regulated by histone acetyltransferase (HAT) complexes, such as the GCN5 complex and the NuA4/Tip60 complex. However, the roles of the HAT complexes during MYC function in cancer have not been well characterized. We recently showed that adenovirus E1A and its N-terminal 80 aa region, E1A 1-80, interact with the NuA4 complex, through the E1A TRRAP-targeting (ET) domain, and enhance MYC association with the NuA4 complex. We show here that the ET domain mainly targets the MYC-NuA4 complex. By global gene expression analysis using E1A 1-80 and deletion mutants, we have identified a panel of genes activated by targeting the MYC-NuA4 complex and notably enriched for genes involved in ribosome biogenesis and gene expression. A second panel of genes is activated by E1A 1-80 targeting of both the MYC-NuA4 complex and p300, and is enriched for genes involved in DNA replication and cell cycle processes. Both panels of genes are highly expressed in cancer cells. Since the ET domain is essential for E1A-mediated cellular transformation, our results suggest that MYC and the NuA4 complex function cooperatively in cell transformation and cancer.

The adenoviral E1A N-terminal domain represses MYC transcription in human cancer cells by targeting both p300 and TRRAP and inhibiting MYC promoter acetylation of H3K18 and H4K16.

Human cancers frequently arise from increased expression of proto-oncogenes, such as MYC and HER2. Understanding the cellular pathways regulating the transcription and expression of proto-oncogenes is important for targeted therapies for cancer treatment. Adenoviral (Ad) E1A 243R (243 aa residues) is a viral oncoprotein that interacts with key regulators of gene transcription and cell proliferation. We have shown previously that the 80 amino acid N-terminal transcriptional repression domain of E1A 243R (E1A 1-80) can target the histone acetyltransferase (HAT) p300 and repress HER2 in the HER2-overexpressing human breast cancer cell line SKBR3. Expression of E1A 1-80 induces death of SKBR3 and other cancer cell lines. In this study, we performed total cell RNA sequence analysis and identified MYC as the regulatory gene for cellular proliferation most strongly repressed by E1A 1-80. By RT-quantitative PCR analysis we show that repression of MYC in SKBR3 cells occurs early after expression of E1A 1-80, suggesting that MYC may be an early responder of E1A 1-80-mediated transcriptional repression. Of interest, while E1A 1-80 repression of MYC occurs in all eight human cancer cell lines examined, repression of HER2 is cell-type dependent. We demonstrate by ChIP analysis that MYC transcriptional repression by E1A 1-80 is associated with inhibition of acetylation of H3K18 and H4K16 on the MYC promoter, as well as inhibition of RNA Pol II binding to the MYC promoter. Deletion mutant analysis of E1A 1-80 suggests that both p300/CBP and TRRAP are involved in E1A 1-80 repression of MYC transcription. Further, E1A 1-80 interaction with p300/CBP and TRRAP is correlated with inhibition of H3K18 and H4K16 acetylation on the MYC promoter, respectively. Our results indicate that E1A 1-80 may target two important pathways for histone modification to repress transcription in human cancer cells.

Ad E1A 243R oncoprotein promotes association of proto-oncogene product MYC with the NuA4/Tip60 complex via the E1A N-terminal repression domain.

The adenovirus E1A 243R oncoprotein targets TRRAP, a scaffold protein that assembles histone acetyltransferase (HAT) complexes, such as the NuA4/Tip60 complex which mediates transcriptional activity of the proto-oncogene MYC and helps determine the cancer cell phenotype. How E1A transforms cells through TRRAP remains obscure. We performed proteomic analysis with the N-terminal transcriptional repression domain of E1A 243R (E1A 1-80) and showed that E1A 1-80 interacts with TRRAP, p400, and three other members of the NuA4 complex - DMAP1, RUVBL1 and RUVBL2 - not previously shown to associate with E1A 243R. E1A 1-80 interacts with these NuA4 components and MYC through the E1A TRRAP-targeting domain. E1A 243R association with the NuA4 complex was demonstrated by co-immunoprecipitation and analysis with DMAP1, Tip60, and MYC. Significantly, E1A 243R promotes association of MYC/MAX with the NuA4/Tip60 complex, implicating the importance of the MYC/NuA4 pathway in cellular transformation by both MYC and E1A.

The adenovirus E1A oncoprotein N-terminal transcriptional repression domain enhances p300 autoacetylation and inhibits histone H3 Lys18 acetylation.

Expression of the adenovirus E1A N-terminal transcription repression domain alone (E1A 1-80) represses transcription from specific promoters such as HER2 [1] and from reconstituted chromatin [2]. Significantly, E1A 1-80 can induce the death of human breast cancer cells over-expressing the HER2 oncogene [1] as well as other cancer cells. Here, we report that E1A 1-80 alone is sufficient to inhibit H3K18 acetylation in vivo and p300-mediated H3K18 acetylation in reconstituted chromatin. Of interest, hypoacetylation of H3K18 has been correlated with the survival of tumor cells and the poor prognosis of many cancers [3, 4]. E1A 1-80 enhances p300 autoacetylation and concurrently inhibits H3K18 acetylation in chromatin in a dose-dependent manner. Pre-acetylation of p300 by incubation with acetyl-CoA alone reduces p300's ability to acetylate H3K18 in chromatin. Additional acetylation of p300 in the presence of E1A 1-80 produces stronger inhibition of H3K18 acetylation. These findings indicate that autoacetylation of p300 greatly reduces its ability to acetylate H3K18. The results reported here combined with our previous findings suggest that E1A can repress transcription by multiple strategies, including altering the chromatin modifying activity of p300 and dissociating TFIID from the TATA box thus disrupting formation of the transcription pre-initiation complex [5, 6].

Specific gene inhibition by adenovirus-mediated expression of small interfering RNA.

Specific gene inhibition in mammalian cells can be achieved by the use of small interfering RNA molecules (siRNA). These siRNA molecules can be chemically synthesized and transfected into cells, or directly expressed intracellularly from a plasmid DNA by the function of the cellular RNA polymerase III. We report here that the latter concept can be incorporated into an adenovirus vector to achieve specific gene inhibition in mammalian cells. As an examination of this approach, we have prepared an adenoviral vector capable of expressing siRNA molecules targeting p53 or VprBP/KIAA0800, a cellular protein that interacts with the HIV auxiliary protein Vpr. In both cases, specific reduction in the target protein level was observed after adenoviral infection. The reduction in the protein level was correlated with a specific reduction in the mRNA level. Since many cell types can be efficiently infected by adenoviruses, adenoviral vectors may serve as a useful alternative to other methods for siRNA delivery and gene inhibition, especially when the target cells are refractory to transfection by DNA or RNA.

Identification of the 15FRFG domain in HIV-1 Gag p6 essential for Vpr packaging into the virion.

The auxiliary regulatory protein Vpr of HIV-1 is packaged in the virion through interaction with the Gag C-terminal p6 domain. Virion packaging of Vpr is critical for Vpr to exert functions in the HIV-1 life cycle. Previous studies suggest that Vpr interacts with a (Lxx)4 domain in p6 for virion packaging. In the present study, mutational analysis of HIV-1 Gag p6 domain was performed in the context of the HIV-1 genome to examine the effect on virion packaging of Vpr. Surprisingly, Ala substitutions for Leu44 and Phe45 in the (Lxx)4 domain or deletion of the whole (Lxx)4 domain (amino acid #35-52 of the Gag p6 domain) did not affect Vpr virion packaging. Vpr virion packaging was normal when amino acid #1-23 of the Gag p6 domain was preserved. Most importantly, Ala substitutions for Phe15, Arg16 and Phe17 in the context of amino acid #1-23 of the Gag p6 domain abolished Vpr virion packaging. Single Ala substitutions for Phe15 and Phe17 also abolished Vpr virion packaging, whereas Ala substitution for Arg16 had no effect. Our studies have revealed a novel signal sequence for Vpr packaging into the HIV-1 virion. The 15FRFG domain in p6 resembles the FxFG repeat sequences commonly found in proteins of the nuclear pore complex. These results have provided novel insights into the process of virion packaging of Vpr and suggest for the first time that Vpr may recognize the FxFG domain for both virion packaging and association with nuclear pores.

Nicotinamide adenine dinucleotide stimulates oligomerization, interaction with adenovirus E1A and an intrinsic dehydrogenase activity of CtBP.

The C-terminal region of adenovirus E1A interacts with the transcriptional corepressor, CtBP. The mechanism of transcriptional regulation by CtBP is not known. CtBP shares a significant homology with NAD(+)-dependent D2-hydroxy acid dehydrogenases. CtBP binds to NAD(+) and NADH. Both forms of the dinucleotide stimulate oligomerization of native CtBP and enhance complex formation with E1A. CtBP also has a slow dehydrogenase activity. Interaction of CtBP with E1A reduces the dehydrogenase activity. Our results raise the possibility that the oxidation/reduction reactions of CtBP may regulate transcription. Thus, CtBP is a unique transcriptional regulator with an enzymatic activity similar to metabolic dehydrogenases. The levels of intracellular nicotinamide adenine dinucleotide may modulate transcriptional activity of CtBP.

HIV-1 auxiliary regulatory protein Vpr promotes ubiquitination and turnover of Vpr mutants containing the L64P mutation.

The auxiliary regulatory protein Vpr of HIV-1 possesses several biological activities which are believed to facilitate HIV-1 replication and pathogenesis. In this report, experimental evidence suggests a novel biological activity of Vpr: facilitation of the turnover of Vpr mutants bearing the L64P mutation. This novel activity of Vpr was shared by Vpr molecules from different subtypes of HIV-1. Co-expression of the wild type Vpr with the VprW54A/L64P mutant resulted in normal synthesis of the mutant mRNA but enhanced ubiquitination and turnover of the mutant protein. These results suggest that Vpr may interact with the ubiquitin/proteasome pathway to regulate the stability of viral or cellular proteins.

[Study on the clinical value of serum cardiac troponin T in early diagnosing of acute non-Q-wave myocardial infarction and prognostic evaluation].

OBJECTIVE: To investigate the value of serum cardiac troponin T (cTnT) in diagnosing earlier acute non-Q-wave myocardial infarction (NQMI) and judging the prognosis. METHODS: Seventy-four NQMI patients and 118 Q-wave myocardial infarction (QMI) patients were studied. Serum cTnT and MB isoenzyme of creatine kinase (CK-MB) levels were monitored on fixed time. On the 15th day of hospitalization, 99 mTc-MIBI myocardial single photon emission computed tomography (SPECT) was performed to assess the infarct size index. Clinical informations of the two groups such as cardiac dysfunction, re-infarction, fatal cadiac arrhythmia, sudden death were collected. RESULTS: The time for serum cTnT beginning to rise was earlier than CK-MB. Its peak time value was paralled to that of CK-MB, and cTnT elevation lasted longer than CK-MB. Serum cTnT and CK-MB peak value showed positive correlation with the infarct size index (both P<0.01). The peak values of cTnT and CK-MB in NQMI group were lower than those in QMI group, and the infarct size was smaller than QMI group (all P<0.05). The frequencies of cardiac events were significantly raised in both groups when there was a high level of serum cTnT. But the proportion in NQMI group was less than those in QMI group (P<0.05). The cardiac events in NQMI group were less than that in QMI group (P<0.05). CONCLUSION: Serum cTnT is an effective marker for diagnosing earlier NQMI, detecting myocardial damage, estimating infarct size and prognosis in the nearly future.

CtBP2 proteome: Role of CtBP in E2F7-mediated repression and cell proliferation.

C-terminal binding protein (CtBP) family transcriptional corepressors include CtBP1 and CtBP2. While CtBP1 and CtBP2 share significant amino acid sequence homology, CtBP2 possesses a unique N-terminal domain that is modified by acetylation and contributes to exclusive nuclear localization. Although CtBP1 and CtBP2 are functionally redundant for certain activities during vertebrate development, they also perform unique functions. Previous studies have identified several CtBP1-interacting proteins that included other transcriptional corepressors, DNA-binding repressors and histone modifying enzymatic components such as the histone deacetylases and the histone demethylase LSD-1. Here, we carried out an unbiased proteomic analysis of CtBP2-associated proteins and discovered the association of several components of the CtBP1 proteome as well as novel interactions. The CtBP2 proteome contained components of the NuRD complex and the E2F family member E2F7. E2F7 interacted with the hydrophobic cleft region of CtBP1 and CtBP2 through a prototypical CtBP binding motif, PIDLS. E2F7 repressed E2F1 transcription, inhibited cell proliferation in a CtBP-dependent fashion. Our study identified CtBP as a corepressor of E2F7 and as a regulator of DNA damage response.

Interaction of CtBP with adenovirus E1A suppresses immortalization of primary epithelial cells and enhances virus replication during productive infection.

Adenovirus E1A induces cell proliferation, oncogenic transformation and promotes viral replication through interaction with p300/CBP, TRRAP/p400 multi-protein complex and the retinoblastoma (pRb) family proteins through distinct domains in the E1A N-terminal region. The C-terminal region of E1A suppresses E1A/Ras co-transformation and interacts with FOXK1/K2, DYRK1A/1B/HAN11 and CtBP1/2 (CtBP) protein complexes. To specifically dissect the role of CtBP interaction with E1A, we engineered a mutation (DL→AS) within the CtBP-binding motif, PLDLS, and investigated the effect of the mutation on immortalization and Ras cooperative transformation of primary cells and viral replication. Our results suggest that CtBP-E1A interaction suppresses immortalization and Ras co-operative transformation of primary rodent epithelial cells without significantly influencing the tumorigenic activities of transformed cells in immunodeficient and immunocompetent animals. During productive infection, CtBP-E1A interaction enhances viral replication in human cells. Between the two CtBP family proteins, CtBP2 appears to restrict viral replication more than CtBP1 in human cells.