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Results for “phase 2”

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PubMed2005

A systems model of training for patients in phase 2 cardiac rehabilitation.

BACKGROUND: The aim of this study was to apply a systems model of training for athletes in patients with coronary artery disease (CAD) undergoing phase 2 cardiac rehabilitation. METHODS: Data from six patients with CAD undergoing 20 conventional training sessions were used to test this model. The method required daily training quantification using heart rate, and regular assessment of real exercise tolerance using a constant-duration test. Convolution of training quantity with real exercise tolerance was provided for every patient model exercise tolerance, by minimizing the residual sum of squares. RESULTS: The results showed that application of the systems model of training to the six patients resulted in a strong fit between real and model exercise tolerances: r(2) = 0.77, 0.79, 0.83, 0.84, 0.85 and 0.92, respectively (P < 0.05). DISCUSSION: Moreover, the systems model admitted for all patients corresponded to one first-order transfer function, which was fitness. This result was in contrast with the systems models reported in athletes and in a patient with CAD undergoing phase 3 cardiac rehabilitation which were found to include two first-order transfer functions: fitness and fatigue, simultaneously. CONCLUSION: The systems model of training of patients with CAD undergoing phase 2 suggested two practical consequences: first, the improvement of exercise tolerance is directly related to training, and consequently second, patients who enter immediately phase 3 training may prevent a decrease in their exercise tolerance.

Adult↗

PubMed1996

Phase 2 reentry as a mechanism of initiation of circus movement reentry in canine epicardium exposed to simulated ischemia.

OBJECTIVES: Myocardial ischemia results in an early phase of arrhythmias that primarily involves reentrant mechanisms. However, the trigger that initiates reentry remains unknown. We studied the initiation of reentry attending the development of electrical heterogeneity during simulated ischemia in isolated canine right ventricular subepicardium. METHODS: Preparations consisted of thin epicardial sheets in which action potentials were recorded at 4 sites with intracellular microelectrodes. Tissues were superfused with a hyperkalemic, hypoxic and acidotic 'ischemic' solution. RESULTS: Simulated ischemia produced a 40-70% abbreviation of the action potential at some epicardial sites but not others, primarily by suppressing development of the action potential plateau (or dome). This typically created a marked dispersion of repolarization within the preparation. Local re-excitation ensued when the action potential dome propagated from sites where it was maintained to sites where it was abolished. This mechanism, termed 'phase 2 reentry', produced an extrasystole which then initiated one or more cycles of circus movement reentry. Tachycardias consisting of repetitive reentry occurred in larger tissues. The window for reentry occurred over a range of stimulation rates that shifted to faster rates as ischemia progressed. The transient outward current blocker, 4-aminopyridine, restored the dome at all sites by reversing the ischemia-induced abbreviation of the action potential. Thus, block of the transient outward current restored electrical homogeneity and abolished all reentrant activity within the epicardial preparations. CONCLUSION: Our results implicate phase 2 reentry as a new mechanism for genesis of extrasystoles during simulated ischemia and identify this mechanism as a trigger of circus movement reentry. Validation of this hypothesis awaits the results of future studies using high-resolution recording techniques.

Action Potentials↗

PubMed2026

Safety and immunogenicity of an mRNA COVID-19 vaccine administered to adults: A phase 2, randomized, active-controlled trial.

We conducted a phase 2, randomized, active-controlled, observer-blind study (NCT05960097) among healthy adults ≥18 y of age who completed a primary COVID-19 mRNA vaccination series, with or without a booster, ≥3 months earlier. Participants were randomized (1:1:1:1:1) to either receive an investigational bivalent mRNA COVID-19 vaccine encoding ancestral D614G and Omicron BA.4-5 spike proteins (CV0701 mRNA vaccine) at one of three dose levels, an investigational monovalent mRNA COVID-19 vaccine encoding the Omicron BA.4-5 spike protein (CV0601 mRNA vaccine), or a licensed Original Wuhan/Omicron BA.4-5 bivalent mRNA COVID-19 vaccine. The primary objectives were to evaluate reactogenicity, safety and immunogenicity post-vaccination. Secondary and tertiary objectives were to further evaluate humoral and cell-mediated immunity post-vaccination. In total, 425 participants were vaccinated and 381 were included in the Day 29 per-protocol immunogenicity analysis. Most solicited events were mild to moderate. No vaccine-related serious adverse events or myocarditis/pericarditis cases were reported. For the CV0701 mRNA vaccine, a dose-dependent increase in Day 29 neutralizing titers against ancestral D614G and Omicron BA.4-5 was observed. Neutralizing titers against ancestral D614G and Omicron BA.4-5 declined by Days 91 and 181, but remained above baseline. Similar immune responses were observed for the CV0601 mRNA vaccine. At Day 8, CD4+ T cells (Th1 profile) increased in all study groups and CD8+ T cells increased in all study groups, except the lowest CV0701 dose group. The CV0701 and CV0601 mRNA vaccines elicited robust humoral and cellular immunity with an acceptable safety profile, comparable to a licensed, bivalent mRNA vaccine. Clinical Trial Registration EU CT number: 2023-504596-25-00 ClinicalTrials.gov: NCT05960097.

Humans↗

PubMed1985

Recombinant DNA human interferon alpha 2 in advanced breast cancer: a phase 2 trial.

Effectiveness of recombinant DNA (rDNA) human interferon alpha 2 (IFN alpha 2) in advanced breast cancer was evaluated in 14 patients who had received prior endocrine and/or cytotoxic therapy. After randomization, 7 patients received IFN alpha 2 two million IU m-2 day-1, s.c., 3 times a week (schedule 1) and 7 patients received 50 million IU m-2 day-1, i.v., for 5 consecutive days, every 3 weeks (schedule 2). Treatment duration was 4-21 weeks in schedule 1 and 6-24 weeks (2-8 courses) in schedule 2. Regressions were not achieved with either schedule. Treatment was associated with significant toxicity and was more severe in schedule 2. Dose limiting toxicities were leukopenia, elevation of liver enzymes, hyperglycemia and fatigue. Serum IFN activity was low or undetectable in patients on schedule 1 and high in patients on schedule 2. At 24 h, serum IFN activity was detectable in only 1/6 patients on schedule 1 as compared to 3/7 patients on schedule 2. IFN neutralizing factors were detected in the serum of only 1 patient prior to treatment but none were detected in any of the patients during or after discontinuation of treatment (4-24 weeks). IFN alpha 2 increased the expression of both HLA class 1 antigens and beta 2 microglobulin in peripheral blood lymphocytes in vivo. This effect was dose related.

Adult↗

PubMed2004

[Phase 2 clinical study of 123I-N-(2-diethylaminoethyl)-2-iodobenzamide in the diagnostic of primary and metastatic ocular melanoma].

PURPOSE: Iodobenzamides are reported to possess an affinity for melanoma. A first selected compound, BZA, was studied in a phase 2 clinical trial on 159 patients as an imaging agent for the detection of primary melanoma and metastases with good results. We report the results of a second phase 2 clinical trial on 40 patients with a new radiopharmaceutical BZA2 (an orthoiodinated BZA analog), which was expected to provide quality images sooner after injection and with better imaging contrast. PATIENTS AND METHODS: Performance was evaluated in 40 patients classified with primary ocular lesions (12), suspicion of metastases of ocular or cutaneous origin (15), or with no known secondary lesion (13), and results were compared with conventional investigation techniques (ophthalmoscopy, ultrasonography, and angiography for ocular melanoma, whole-body CT scan and ultrasonography for metastases). RESULTS: No adverse events were recorded. The overall results on a per patient basis showed a sensitivity of 78% and a specificity of 95%. The four false negatives observed were ocular lesions (three with a thickness<3mm and one achromic), but all the proven secondary lesions were imaged. Moreover, negative BZA2 scintigraphy in cases of suspicious lesions led to the correction of two diagnoses: the prostatic origin of bone metastases and the endocrine tumor origin (APUD system) of an ocular lesion. DISCUSSION: BZA2 scintigraphy is an easy test with good tolerance. In the diagnosis of ocular primary melanoma, the sensitivity of the test is 64%, although limited by the thickness (3mm) and the pigmentation of the lesion. However, the BZA2 scintigraphy is a very useful test for the detection of melanoma metastases, with a sensitivity of 100% and a specificity of 95%. CONCLUSION: BZA2 scintigraphy showed good tolerance in patients and it appears promising for differential diagnosis, staging, and restaging of melanoma.

Benzamides↗

PubMed2006

4-Hydroxy-2-nonenal upregulates endogenous antioxidants and phase 2 enzymes in rat H9c2 myocardiac cells: protection against overt oxidative and electrophilic injury.

This study was undertaken to determine if 4-hydroxy-2-nonenal (HNE) could upregulate antioxidants and phase 2 enzymes in rat H9c2 myocardiac cells, and if the upregulated defenses led to cytoprotection against oxidative and electrophilic injury. Incubation of H9c2 cells with HNE at noncytotoxic concentrations resulted in significant induction of cellular catalase, glutathione (GSH), GSH S-transferase (GST), and NAD(P)H:quinone oxidoreductase 1 (NQO1), as determined by enzyme activity and/or protein expression. HNE treatment caused increased mRNA expression of catalase, gamma-glutamylcysteine ligase, GST-A1, and NQO1. Pretreatment of H9c2 cells with HNE led to significant protection against cytotoxicity induced by reactive oxygen and nitrogen species. HNE-pretreated cells also exhibited increased resistance to injury elicited by subsequent cytotoxic concentrations of HNE. Taken together, this study demonstrates that several antioxidants and phase 2 enzymes in H9c2 cells are upregulated by HNE and that the increased defenses afford protection against overt oxidative and electrophilic cardiac cell injury.

Aldehydes↗

PubMed2001

An assessment of the impact of California's Phase 2 Reformulated Gasoline on ozone air quality.

California's Phase 2 Reformulated Gasoline (CaRFG), introduced early in 1996, represents an important step toward attainment of ozone standards. Studies of vehicle emissions and ambient air quality data have reported substantial reductions of ozone precursors due to CaRFG. This study uses daily measurements of regional ozone and meteorology to estimate the effect of CaRFG on ozone concentrations in three areas of California. In each area, a regression model was used to partially account for the daily effects of meteorology on area-wide ozone maxima for May-October. The statistical models are based on combinations of air temperature aloft (approximately 5000 ft), surface air temperatures, and surface wind speeds. Estimated ozone benefits were attributed to CaRFG after accounting for meteorology, which improved the precision of the estimates by approximately 37-57% based on a resampling analysis. The ozone benefits were calculated as the difference in ozone times the proportion of the reductions of hydrocarbons and nitrogen oxides attributed to CaRFG by the best available emission inventories. Ozone benefits attributed to CaRFG (with approximately 90% confidence) are 8-13% in the Los Angeles area, -2-6% in the San Francisco Bay area overall with greater benefits in two major subregions, and 3-15% in the Sacramento area.

Air Pollutants↗

PubMed2003

Effect of in utero-administered coumestrol, equol, and organic selenium on biomarkers for phase 2 enzyme capacity and redox status.

The aim of the present study was to investigate the effect of in utero administration of coumestrol, equol, and selenium-enriched yeast on selected hepatic phase 2 enzymes, plasma hormone levels, and markers for redox status in plasma and red blood cells (RBCs). The test compounds were administered via the diet to pregnant Sprague-Dawley rats throughout gestation. Within 24 h following delivery dams and offspring were sacrificed, and blood, liver, and reproductive organs were sampled. Coumestrol, equol, and selenium-enriched yeast did not significantly affect hepatic glutathione S-transferase (GST), quinone reductase (QR), or RBC glutathione peroxidase (GPx) in the offspring, whereas significant increases in GST, QR, and GPx activities in dams were observed following administration of selenium-enriched yeast. The level of 17beta-estradiol in offspring from coumestrol-exposed dams was significantly increased compared with the control. The present results indicate that selenium-enriched yeast, coumestrol, and equol affect selected hepatic phase 2 enzymes and GPx in RBC in dams, whereas the offspring in general were refractive to the employed treatments. Further studies are warranted to investigate whether the observed in utero effects imposed by the selected plant compounds confer permanent alterations on the health status of the animal resulting in an altered resistance to cancer.

Analysis of Variance↗

PubMed1972

Chromatid breakage: differential effect of inhibitors of DNA synthesis during G 2 phase.

The cell cycle specificity of chromatid breakage induced by inhibitors of DNA synthesis depends on the mechanism of drug action. 5-Hydroxy-2-formylpyridine thiosemicarbazone, hydroxyurea, and guanazole, compounds that inhibit ribonucleotide reductase, do not cause chromatid breakage during G(2) phase. In contrast, two active antitumor agents, arabinosylcytosine and 5-azacytidine, which are either incorporated into polynucleotides or affect DNA polymerase, produce chromatid breakage during G(2) phase. All of these agents except guanazole also induce breakage in S phase.

Animals↗

PubMed2001

Phase 2 early afterdepolarization as a trigger of polymorphic ventricular tachycardia in acquired long-QT syndrome : direct evidence from intracellular recordings in the intact left ventricular wall.

BACKGROUND: This study examined the role of phase 2 early afterdepolarization (EAD) in producing a trigger to initiate torsade de pointes (TdP) with QT prolongation induced by dl-sotalol and azimilide. The contribution of transmural dispersion of repolarization (TDR) to transmural propagation of EAD and the maintenance of TdP was also evaluated. METHODS AND RESULTS: Transmembrane action potentials from epicardium, midmyocardium, and endocardium were recorded simultaneously, together with a transmural ECG, in arterially perfused canine and rabbit left ventricular preparations. dl-Sotalol preferentially prolonged action potential duration (APD) in M cells dose-dependently (1 to 100 micromol/L), leading to QT prolongation and an increase in TDR. Azimilide, however, significantly prolonged APD and QT interval at concentrations from 0.1 to 10 micromol/L but shortened them at 30 micromol/L. Unlike dl-sotalol, azimilide (>3 micromol/L) increased epicardial APD markedly, causing a diminished TDR. Although both dl-sotalol and azimilide rarely induced EADs in canine left ventricles, they produced frequent EADs in rabbits, in which more pronounced QT prolongation was seen. An increase in TDR by dl-sotalol facilitated transmural propagation of EADs that initiated multiple episodes of spontaneous TdP in 3 of 6 rabbit left ventricles. Of note, although azimilide (3 to 10 micromol/L) increased APD more than dl-sotalol, its EADs often failed to propagate transmurally, probably because of a diminished TDR. CONCLUSIONS: This study provides the first direct evidence from intracellular action potential recordings that phase 2 EAD can be generated from intact ventricular wall and produce a trigger to initiate the onset of TdP under QT prolongation.

Action Potentials↗

PubMed1999

Relation of structure of curcumin analogs to their potencies as inducers of Phase 2 detoxification enzymes.

A series of naturally occurring as well as synthetic structural analogs of the dietary constituent curcumin were examined in order to elucidate which portions of the molecule are critical for the ability to induce Phase 2 detoxification enzymes in murine hepatoma cells, and hence to assess the chemoprotective potential of these compounds. Two groups of compounds were studied: classical Michael reaction acceptors such as curcumin and related beta-diketones such as dibenzoylmethane which lack direct Michael reactivity. The presence of two structural elements was found to be required for high inducer potency: (i) hydroxyl groups at ortho-position on the aromatic rings and (ii) the beta-diketone functionality. All curcuminoids elevate the specific activity of quinone reductase in both wild type and mutant cells defective in either the aryl hydrocarbon (Ah) receptor or cytochrome P4501A1 activity. This indicates that neither binding to this receptor, nor metabolic activation by P4501A1 are required for the signaling process originating from this family of electrophiles and ultimately resulting in Phase 2 enzyme induction.

Animals↗

PubMed2004

The chemical inducibility of mouse cardiac antioxidants and phase 2 enzymes in vivo.

The recognition of the critical involvement of oxidative and electrophilic stress in cardiac disorders has led to extensive investigation of the protective effects of exogenous antioxidants on cardiac injury. On the other hand, another strategy for protecting against oxidative/electrophilic cardiac injury may be through induction of the endogenous antioxidants and phase 2 enzymes in myocardium by chemical inducers. However, our understanding of the chemical inducibility of cardiac antioxidants/phase 2 enzymes in vivo is very limited. In addition, careful studies on the basal levels of a scope of endogenous antioxidants/phase 2 enzymes in myocardium as compared with other tissues, such as liver, are lacking. Accordingly, this study was undertaken to determine the basal levels of endogenous antioxidants/phase 2 enzymes, including superoxide dismutase (SOD), catalase, reduced glutathione (GSH), GSH peroxidase (GPx), glutathione reductase (GR), GSH S-transferase (GST), and NAD(P)H:quinone oxidoreductase 1 (NQO1), and investigate the inducibility of the above antioxidants/phase 2 enzymes by the chemoprotectant, 1,2-dithiole-3-thione (D3T), in cardiac as well as hepatic tissues in C57BL/6 mice. Our results demonstrated that in C57BL/6 mice, the levels of catalase, GSH, GPx, GR, and GST were significantly lower in cardiac tissue than in hepatic tissue. The level of total SOD did not differ significantly between mouse heart and liver. Notably, heart contained a much higher NQO1 activity than liver. Immunoblotting and RT-PCR analyses further demonstrated the high expression of NQO1 protein and mRNA in myocardium. Oral administration of D3T at 0.25 and 0.5 mmol/kg body weight for 3 consecutive days resulted in a significant induction of cardiac SOD, catalase, GR, GST, and NQO1. No significant induction of cardiac GSH and GPx was observed with the above D3T treatment. Only GR, GST, and NQO1 in mouse liver were induced by the D3T treatment. Unexpectedly, we observed a significant D3T dose-dependent decrease in hepatic GPx activity. Taken together, this study demonstrates for the first time that: (1) the expression of NQO1 is remarkably high in mouse myocardium though other cardiac antioxidants/phase 2 enzymes are relatively lower as compared with liver; (2) a number of endogenous antioxidants/phase 2 enzymes in mouse cardiac tissue can be significantly induced by D3T following oral administration; and (3) the inducibility of endogenous antioxidants/phase 2 enzymes by D3T differs between mouse cardiac and hepatic tissues. This study provides a basis for future investigation of the cardioprotection of chemically induced endogenous antioxidants and phase 2 enzymes in myocardium in animal models of oxidative/electrophilic cardiac disorders.

Animals↗

PubMed2006

A phase 2 study of TZT-1027, administered weekly to patients with advanced non-small cell lung cancer following treatment with platinum-based chemotherapy.

INTRODUCTION: : TZT-1027, a derivative of dolastatin-10, has a wide spectrum of in vitro activity against cancer cell lines. We conducted a phase 2 trial of TZT-1027 in patients with previously treated non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients with stage IV or recurrent NSCLC who had received one prior platinum-based chemotherapy regimen were eligible. Patients received 2.4mg/m(2) of TZT-1027 on days 1 and 8 of a 21-day cycle. The primary endpoint was response rate as measured by RECIST. RESULTS: Thirty-two patients were enrolled (16 women, 16 men). The most common grade 3/4 adverse effects were leukopenia and neutropenia. Four patients died within 30 days of receiving TZT-1027, three from progressive disease and one with pneumonia and neutropenia. No objective response was observed (0% observed rate, 95% confidence interval 0-11%). The median time to progression was 1.5 months. The median overall survival was 8.5 months. CONCLUSIONS: This phase 2 trial showed that TZT-1027 administered on days 1 and 8 of a 21-day cycle had no anticancer activity. Further development of TZT-1027 in patients with previously treated NSCLC is not warranted.

Adult↗

PubMed2003

Treatment of relapsed CD20+ Hodgkin lymphoma with the monoclonal antibody rituximab is effective and well tolerated: results of a phase 2 trial of the German Hodgkin Lymphoma Study Group.

This phase 2 trial was performed to evaluate the safety and efficacy of the chimeric monoclonal anti-CD20 antibody rituximab in patients with relapsed lymphocyte-predominant Hodgkin lymphoma or other CD20(+) subtypes of Hodgkin disease (HD). Eligibility criteria required expression of the CD20 antigen on more than 30% of malignant cells. Fourteen patients were treated with 4 weekly intravenous infusions of rituximab (375 mg/m(2)). All patients had at least one prior chemotherapy (median, 2). The median time from first diagnosis was 9 years. Adverse events, such as rhinitis, fever, chills, and nausea, were usually transient and of mild to moderate grade, allowing outpatient treatment in most cases. All patients completed treatment and were eligible for a response. The overall response in 14 assessable patients was 86%, with 8 complete remissions and 4 partial remissions, and 2 patients with progressive disease. At a median follow-up of 12 months, 9 of 12 responders were in remission. The median duration of response has not been reached yet (20+ months). We conclude that rituximab is both safe and effective in a subgroup of CD20(+) patients with HD.

Adolescent↗

PubMed1993

A phase 2 study of cisplatin in patients with hepatocellular carcinoma.

A phase 2 study of cisplatin was performed in 28 previously untreated patients with unresectable hepatocellular carcinoma. The drug was given intravenously at a dose of 80 mg/m2/day every 4 weeks. Of 26 patients evaluated, 4 (15.4%) showed partial responses lasting for > 3 months, while no patient achieved a complete response. Of 22 patients whose serum level of alpha-fetoprotein (AFP) was high (> 400 ng/ml) before treatment, 6 (27.3%) showed a > 50% reduction in serum AFP levels after treatment. The current study indicates that cisplatin is an anticancer agent worthy of further testing in patients with this disease.

Adult↗

PubMed2004

Phase 2 study of BCNU and temozolomide for recurrent glioblastoma multiforme: North American Brain Tumor Consortium study.

The purpose of this study was to evaluate the activity, measured in terms of progression-free survival (PFS) and response rates, of 1,3-bis(chloro-ethyl)-1-nitrosourea (BCNU) plus temozolomide in adult patients with recurrent glioblastoma multiforme. The phase 2 dose and schedule for this trial was BCNU 150 mg/m(2) i.v. followed in 2 h by temozolomide 550 mg/m(2) as a single oral dose. Treatment was repeated every 6 weeks for up to 8 cycles unless tumor progression was documented. The primary end point was PFS at 6 months (PFS-6). Response was a secondary end point, measured by MR imaging, neurological status, and steroid requirements prior to each 6-week cycle. The median age of eligible patients was 53, and 89.5% had no prior chemotherapy. All patients were evaluable for toxicity and time to progression. The PFS-6 was 21%. Overall survival was 68% at 6 months and 26% at 1 year. The MRI response for 36 patients was 2 partial responses, 2 minor responses, 19 cases of stable disease, and 13 immediate progressions. Median survival was 34 weeks, and median PFS was 11 weeks. Toxicity was primarily myelosuppression; no toxic deaths occurred. Historical phase 2 study data in this patient population show a PFS-6 of 15%. Recent data for use of temozolomide alone have shown a PFS-6 of 21%. We conclude that BCNU plus temozolomide when used in these doses and schedule has only modest activity, with significant toxicity, and appears to be no more effective than single-agent temozolomide.

Adult↗

PubMed2005

Phase 2 reentry in man.

BACKGROUND: Ventricular extrasystoles are characterized by a fixed coupling interval to the last QRST complex preceding it. OBJECTIVES: We hypothesized that this QRST complex differed from QRST complexes of other sinus beats not followed by ventricular extrasystoles. Further, we investigated whether phase 2 reentry, demonstrated in animal experiments to initiate ventricular extrasystoles, ventricular tachycardia, and ventricular fibrillation, also plays a role in humans. METHODS: We examined 18 patients with ventricular extrasystoles and/or ventricular tachycardia by signal averaging of the ECG (group A) or by single-beat analysis of intracardiac electrograms (group B). Group A consisted of six patients without structural heart disease and one patient with the Brugada syndrome. Six of the seven patients had right ventricular outflow tract ventricular extrasystoles. Group B consisted of 11 patients undergoing radiofrequency ablation. Eight of the 11 patients had right ventricular outflow tract extrasystoles. RESULTS: In six of the seven patients in group A, we demonstrated significant ST-elevation and/or T-wave changes in the sinus beat preceding ventricular extrasystoles compared with the second last sinus beat in one or more of the three orthogonal leads X, Y, and Z. In 9 of the 11 patients in group B, single-beat analysis of unipolar and bipolar electrograms recorded close to successful ablation sites demonstrated similar changes, that is, ST-elevation (median peak voltage gradient 150 muV, range 0-1,700) and T-wave changes in the sinus beat prior to ventricular ectopy. In addition, J-point elevation was demonstrated in several cases. In total, significant changes were demonstrated in 15 of the 18 patients studied (83%). CONCLUSION: J-point elevation, ST-elevation, and T-wave changes documented in the last sinus beat prior to ventricular extrasystoles are in agreement with phase 2 reentry, suggesting that this may be the responsible mechanism for ventricular extrasystoles and ventricular tachycardia/fibrillation. The phenomenon has been demonstrated in only animal experiments to date.

Adult↗

PubMed2000

The human homolog of Saccharomyces cerevisiae Mcm10 interacts with replication factors and dissociates from nuclease-resistant nuclear structures in G(2) phase.

Mcm10 (Dna43), first identified in Saccharomyces cerevisiae, is an essential protein which functions in the initiation of DNA synthesis. Mcm10 is a nuclear protein that is localized to replication origins and mediates the interaction of the Mcm2-7 complex with replication origins. We identified and cloned a human cDNA whose product was structurally homologous to the yeast Mcm10 protein. Human Mcm10 (HsMcm10) is a 98-kDa protein of 874 amino acids which shows 23 and 21% overall similarity to Schizosaccharomyces pombe Cdc23 and S. cerevisiae Mcm10, respectively. The messenger RNA level of HsMcm10 increased at the G(1)/S-boundary when quiescent human NB1-RGB cells were induced to proliferate as is the case of many replication factors. HsMcm10 associated with nuclease-resistant nuclear structures throughout S phase and dissociated from it in G(2) phase. HsMcm10 associated with human Orc2 protein when overexpressed in COS-1 cells. HsMcm10 also interacted with Orc2, Mcm2 and Mcm6 proteins in the yeast two-hybrid system. These results suggest that HsMcm10 may function in DNA replication through the interaction with Orc and Mcm2-7 complexes.

Amino Acid Sequence↗