Discovery of Sulanemadlin (ALRN-6924), the First Cell-Permeating, Stabilized α-Helical Peptide in Clinical Development

We report the discovery of sulanemadlin (ALRN-6924), the first cell-permeating, stabilized α-helical peptide to enter clinical trials. ALRN-6924 is a "stapled peptide" that mimics the N-terminal domain of the p53 tumor suppressor protein. It binds with high affinity to both MDM2 and MDMX (also known as MDM4), the endogenous inhibitors of p53, to activate p53 signaling in cells having a non-mutant, or wild-type TP53 genotype (TP53-WT). Iterative structure-activity optimization endowed ALRN-6924 with favorable cell permeability, solubility, and pharmacokinetic and safety profiles. Intracellular proteolysis of ALRN-6924 forms a long-acting active metabolite with potent MDM2 and MDMX binding affinity and slow dissociation kinetics. At high doses, ALRN-6924 exhibits on-mechanism anticancer activity in TP53-WT tumor models. At lower doses, ALRN-6924 transiently arrests the cell cycle in healthy tissues to protect them from chemotherapy without protecting the TP53-mutant cancer cells. These results support the continued clinical evaluation of ALRN-6924 as an anticancer and chemoprotection agent.

Abstract P211: The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection

Aim: We investigated whether p53 activation with ALRN-6924 can prevent toxicity in mouse models of acute radiation injury. Materials and methods: ALRN-6924 is a clinical-stage, first-in-class, stabilized cell-permeating alpha-helical peptide that disrupts the interaction of the p53 tumor suppressor protein with its endogenous inhibitors, MDMX and MDM2. In previous experiments it was shown that ALRN-6924 can induce transient, dose-dependent cell cycle arrest in the bone marrow to protect those cells from chemotherapy while not protecting p53-mutant cancer cells. Because radiation (like chemotherapy) preferentially affects proliferating cells, we hypothesized that ALRN-6924 may also protect proliferating cells in normal tissues from radiation-induced cellular toxicity. Cell cycle arrest was measured in the bone marrow of ALRN-6924-treated C57BL/6 mice by flow cytometry using EdU incorporation. Serum levels of macrophage inhibitory cytokine-1 (MIC-1), a biomarker of p53 activation, were measured by ELISA. Cell proliferation and apoptosis were measured in formalin-fixed mouse bone marrow by immunohistochemistry analysis of Ki67 and cleaved PARP, respectively. C57BL/6 mice (n=7/group) were treated with one or more intravenous 2.4 mg/kg doses of ALRN-6924 at 24, 16, 8, or 1 hour (or combinations thereof) or placebo prior to an abdominally targeted (shielded body) 15 Gy radiation dose and then monitored for body weight (BW). Results: MIC-1 was elevated in the serum of ALRN-6924-treated mice in a dose-dependent fashion. Repeated doses of ALRN-6924 every 8 hrs yielded sustained MIC-1 elevation, which correlated with reduced Ki67 positivity in the bone marrow. Treatment-dependent changes in cPARP expression were evident, but minimal in magnitude. In a nonlethal radiation exposure model, ALRN-6924 yielded significant protection from radiation-induced BW loss in a schedule-dependent manner. Placebo-treated mice showed 10% to 15% BW loss five days after irradiation, while mice receiving one or more ALRN-6924 doses 8 hrs prior to irradiation had an average of 4% BW loss (p=0.008, two-sided t test). Conclusions: ALRN-6924 mitigates toxicity in a mouse model of acute radiation injury. The observed radioprotection effect correlates with pharmacodynamic markers of cell proliferation and cell cycle arrest after one or more doses of ALRN-6924, and further supports previous demonstrations of chemoprotection with ALRN-6924. These results provide a rationale to investigate ALRN-6924 as a radioprotective agent.

Citation Format: Allen Annis, David Sutton, Manuel Aivado, Vojislav Vukovic. The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P211.

Phase 1 Trial of ALRN-6924, a Dual Inhibitor of MDMX and MDM2, in Patients with Solid Tumors and Lymphomas Bearing Wild-type TP53

PURPOSE

We describe the first-in-human dose-escalation trial for ALRN-6924, a stabilized, cell-permeating peptide that disrupts p53 inhibition by mouse double minute 2 (MDM2) and MDMX to induce cell-cycle arrest or apoptosis in TP53-wild-type (WT) tumors.

PATIENTS AND METHODS

Two schedules were evaluated for safety, pharmacokinetics, pharmacodynamics, and antitumor effects in patients with solid tumors or lymphomas. In arm A, patients received ALRN-6924 by intravenous infusion once-weekly for 3 weeks every 28 days; arm B was twice-weekly for 2 weeks every 21 days.

RESULTS

Seventy-one patients were enrolled: 41 in arm A (0.16-4.4 mg/kg) and 30 in arm B (0.32-2.7 mg/kg). ALRN-6924 showed dose-dependent pharmacokinetics and increased serum levels of MIC-1, a biomarker of p53 activation. The most frequent treatment-related adverse events were gastrointestinal side effects, fatigue, anemia, and headache. In arm A, at 4.4 mg/kg, dose-limiting toxicities (DLT) were grade 3 (G3) hypotension, G3 alkaline phosphatase elevation, G3 anemia, and G4 neutropenia in one patient each. At the MTD in arm A of 3.1 mg/kg, G3 fatigue was observed in one patient. No DLTs were observed in arm B. No G3/G4 thrombocytopenia was observed in any patient. Seven patients had infusion-related reactions; 3 discontinued treatment. In 41 efficacy-evaluable patients with TP53-WT disease across both schedules the disease control rate was 59%. Two patients had confirmed complete responses, 2 had confirmed partial responses, and 20 had stable disease. Six patients were treated for >1 year. The recommended phase 2 dose was schedule A, 3.1 mg/kg.

CONCLUSIONS

ALRN-6924 was well tolerated and demonstrated antitumor activity.

Abstract C064: The investigational peptide drug ALRN-6924, a dual inhibitor of MDMX and MDM2, is an effective myelopreservation agent

Aim: We investigated whether p53 activation with ALRN-6924 can prevent or reduce chemotherapy-induced hematopoietic toxicity while preserving or enhancing anti-tumor efficacy of chemotherapy in p53-mutant tumors. Materials and methods: ALRN-6924 is a clinical-stage, first-in-class, stabilized cell-permeating alpha-helical peptide that disrupts the interaction of the p53 tumor suppressor protein with its endogenous inhibitors, MDMX and MDM2. For p53 wild-type cells such as normal bone marrow, p53 activation can induce transient, dose-dependent cell cycle arrest, reducing sensitivity to chemotherapy-induced cellular toxicity. For p53-mutant cancer cells, ALRN-6924 has no effect on the cell cycle, leaving them vulnerable to chemotherapy. ALRN-6924-induced cell cycle arrest was measured by flow cytometry in human bone marrow CD34+ cells following incubation with ALRN-6924 ex vivo for 24 hours. DNA synthesis and DNA content were quantified by flow cytometry using EdU incorporation and Hoechst 33342 staining, respectively. Cell cycle arrest in the bone marrow of ALRN-6924-treated C57BL/6 mice was measured by flow cytometry using EdU incorporation in lineage negative, Kit positive hematopoietic stem and progenitor cells. Topotecan-induced DNA damage was measured in human bone marrow CD34+ cells by H2γX incorporation following exposure to vehicle or ALRN-6924 for 24 hours to induce cell cycle arrest, then incubated with topotecan for an additional 24 hours following a wash-out step. Topotecan-induced neutropenia was measured in female C57BL/6 mice following topotecan treatment on days 1-5 and either ALRN-6924 or vehicle on days 0-4. Female C57BL/6 mice bearing subcutaneous p53-mutant MC38 syngeneic tumors were treated with ALRN-6924, vehicle and topotecan on the same dosing regimen and followed until tumors reached >1000mm3. Results: ALRN-6924 induces transient, reversible cell cycle arrest in bone marrow cells in vitro and in vivo, and protects human bone marrow cells against topotecan-induced DNA damage ex vivo. In a mouse model of topotecan-induced neutropenia, ALRN-6924 protected against neutrophil depletion when daily administration started 24 hours prior to the 1st dose and 30 minutes before each subsequent dose of topotecan. ALRN-6924 does not diminish topotecan’s anti-tumor activity in the p53-mutant MC38 syngeneic mouse cancer model, with the ALRN-6924 + topotecan combination yielding modest enhancement of survival. Body weights and mortality data suggest ALRN-6924 and combinations with topotecan were tolerated at the doses tested. Conclusions: ALRN-6924 reduces chemotherapy-induced hematopoietic toxicity in healthy human bone marrow cells ex vivo and in mouse models of topotecan-induced neutropenia in vivo, while preserving or enhancing anti-tumor efficacy in p53-mutant tumors when administered intravenously prior to chemotherapy. These results support the first ALRN-6924 clinical trial for myelopreservation in topotecan-treated small-cell lung cancer patients (NCT04022876). Additional studies are underway to support ALRN-6924 as a tumor type-agnostic myelopreservation agent for cancer patients with tumors bearing p53 mutations who are treated with chemotherapy.

Citation Format: Luis A Carvajal, David Sutton, Mariam Mounir, Joseph McClanaghan, Vincent Guerlavais, Manuel Aivado, Vojislav Vukovic, Allen Annis. The investigational peptide drug ALRN-6924, a dual inhibitor of MDMX and MDM2, is an effective myelopreservation agent [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C064. doi:10.1158/1535-7163.TARG-19-C064

Pitfalls of positivity–new perspectives on the futility of negating negativity

The claim that “thinking positive” betters one's life has become pervasive in our contemporary culture. Proponents of this style of reasoning, including the head of the positive psychology movement, Martin Seligman, claim their goal is to create a field focused on human well-being and the conditions, strengths and virtues that allow people to thrive, and back their standpoint with a great number of studies.

However, critics of the movement have, first of all, pointed out flaws in some of the concepts and studies backing them, and second, performed experiments of their own which show not only that forced positive thinking doesn’t help, but can sometimes be harmful.

More worrisome than disputes in the therapeutic community is the tendency of mass media and our commodified society to abuse these approaches, the end result being a whole scope of popular psychology books which promise wealth, happiness and ideal partners to those prepared to “believe”, and the presence of a horde of self-appointed gurus promising easy answers and quick solutions. This is only a symptom of our contemporary postmodern condition, one well phrased by the Slovenian philosopher Žižek - “the commandment of the ruling ideology is ‘enjoy!”’.

From philosophers of negativity (Nietzsche, Schopenhauer) to psychotherapists dealing with automatic negative thoughts, we come to our proposed field of research in the “neuroscience of negativity”, a search for the biological underpinnings of positivity/negativity, focusing primarily on their relation to Cloningers’ dimensions of personality and mood disorders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

OC-07 - Decoding risk for thromboembolic events in lymphoma patients

INTRODUCTION

There are few prediction tools for estimating the risk of thrombosis but they are based on studies performed on hospitalized medical patients without cancer or on hospitalized neutropenic cancer patients without special consideration to lymphoma patients.

AIM

Aim of our study was to determine incidence of thromboembolic (TE) events in patients with non Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and chronic lymphocytic leukemia (CLL)/ small lymphocytic lymphoma (SLL) who were hospitalized to the lymphoma department in the Clinic of hematology, Clinical Center Serbia, Belgrade and Clinic of hematology, Clinical Center Kragujevac. Also, we assessed 2 predictive models (Padua and Khorana score) and create new model for the identification of lymphoma patients at risk for thromboembolism.

MATERIALS AND METHODS

We reviewed all medical records of patients with with NHL, HL and CLL/SLL diagnosed and treated at two previously mentioned institution between January 2006 and December 2014.

RESULTS

The study population included 1820 eligible lymphoma patients. Of all the patients included in the study, 99 (5.4%) developed at least one TE during a follow-up period of 3 months from the end of therapy. In the final multivariate analysis, the following variables were independently associated with risk of TE: previous VTE and/or arterial events, reduced mobility (ECOG 2-4), obesity (BMI >30 kg/m(2)), extranodal localization, mediastinum involvement, development of neutropenia during therapy and hemoglobin level less than 100g/L. Subsequently, we assigned points for the risk model based on the regression coefficients obtained from the final model and developed Thrombosis Lymphoma (ThroLy) score consisting of all significant variables from the multivariate analysis. The Throly score was arrived at by assigning 2 points for all parameters with an OR >5 in multivariate regression analyses (e.g., previous VTE and arterial events, mediastinum involvement, and BMI) and 1 point for rest all other significant variables. Finally, population were divided into 3 risk categories for TE based on the score from the risk model: low (score 0-1), intermediate (score 2-3) and high (score >3). High risk score had a positive predictive value (probability of TE in those designated high risk) of 65.2%.

CONCLUSIONS

Significance of our investigation is development of score that help phisicians to recruit lymphoma patients at risk for development of thromboembolic complications. Also, we can say that our score is dynamic allowing us to change approach during different phase of therapy and is not limited to outpatient settings or with some complicated laboratory analysis.

Kraepelin's ghost: Late onset schizophrenia, dementia (non)praecox, or paraphrenia? (case report)

Introduction

It is difficult to establish whether a patient has late onset schizophrenia or frontotemporal dementia. The object of the following case report is to point out the difficulty of making a differential diagnosis between these two entities.

Case summary

A 49-year-old female patient was admitted to our hospital after presenting with auditory and visual hallucinations, formal thought disorder, persecutory delusions, ideas of reference, insomnia. Memory, executive function and attentional tasks were severely compromised. Computerized tomography showed incipient frontal lobe atrophy. There were no significant abnormalities found in blood and urine samples or physical and neurological examinations. After showing no response to olanzapine, and extrapyramidal side effects to fluphenazine, risperidone was initiated which subsequently led to complete withdrawal of positive symptoms.

Discussion

Patients presenting with psychotic symptoms after the age of 40 presented a diagnostic quandary, as they were less likely to present with negative symptoms, formal thought disorder or affective blunting, and more likely to have systematised delusions and visual hallucinations. Frontotemporal dementia is a disorder that can present itself with cognitive decline and a large range of psychiatric symptoms. The risk of late onset schizophrenia is greater in women, possibly implicating a causative role of female sex hormones. Atypical antipsychotics risperidone and olanzapine seem to be an adequate treatment.

Conclusion

Schizophrenia is a heterogeneous disease with a large variety of clinical manifestations. Special care should be given to patients with age over 40, including neurocognitive assessment, laboratory and hormone tests, and a long-term follow-up.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A randomized phase II study of ganetespib, a heat shock protein 90 inhibitor, in combination with docetaxel in second-line therapy of advanced non-small cell lung cancer (GALAXY-1)

BACKGROUND

This trial was designed to evaluate the activity and safety of ganetespib in combination with docetaxel in advanced non-small cell lung cancer (NSCLC) and to identify patient populations most likely to benefit from the combination.

PATIENTS AND METHODS

Patients with one prior systemic therapy for advanced disease were eligible. Docetaxel (75 mg/m(2) on day 1) was administered alone or with ganetespib (150 mg/m(2) on days 1 and 15) every 3 weeks. The primary end points were progression-free survival (PFS) in two subgroups of the adenocarcinoma population: patients with elevated lactate dehydrogenase (eLDH) and mutated KRAS (mKRAS).

RESULTS

Of 385 patients enrolled, 381 were treated. Early in the trial, increased hemoptysis and lack of efficacy were observed in nonadenocarcinoma patients (n = 71); therefore, only patients with adenocarcinoma histology were subsequently enrolled. Neutropenia was the most common grade ≥3 adverse event: 41% in the combination arm versus 42% in docetaxel alone. There was no improvement in PFS for the combination arm in the eLDH (N = 114, adjusted hazard ratio (HR) = 0.77, P = 0.1134) or mKRAS (N = 89, adjusted HR = 1.11, P = 0.3384) subgroups. In the intent-to-treat adenocarcinoma population, there was a trend in favor of the combination, with PFS (N = 253, adjusted HR = 0.82, P = 0.0784) and overall survival (OS) (adjusted HR = 0.84, P = 0.1139). Exploratory analyses showed significant benefit of the ganetespib combination in the prespecified subgroup of adenocarcinoma patients diagnosed with advanced disease >6 months before study entry (N = 177): PFS (adjusted HR = 0.74, P = 0.0417); OS (adjusted HR = 0.69, P = 0.0191).

CONCLUSION

Advanced lung adenocarcinoma patients treated with ganetespib in combination with docetaxel had an acceptable safety profile. While the study's primary end points were not met, significant prolongation of PFS and OS was observed in patients >6 months from diagnosis of advanced disease, a subgroup chosen as the target population for the phase III study.

Determinants of intention to work abroad of college and specialist nursing graduates in Serbia

BACKGROUND

In a country with a poor economy and limited job opportunities, the outmigration of students is not commonly perceived as a problem but rather is perceived as a solution to the high unemployment facing young health professionals.

OBJECTIVES

Study objectives were to identify the prevalence of intention to work abroad of nursing graduates to point to the predictors of intention to work abroad and predictors of having a firm plan to work in a foreign country.

DESIGN

Descriptive study, a survey.

SETTINGS

College and specialist nursing schools, Serbia.

PARTICIPANTS

719 nursing graduates from the 2012/2013 school year.

METHODS

Voluntarily completed a questionnaire that was designed with regard to similar surveys administered in EU-candidate countries during the pre-accession period. Data were analysed with descriptive and multivariate regression analyses.

RESULTS

Almost 70% (501) of respondents indicated an intention to work abroad. Of the nurses, 13% already had established a firm plan to work abroad. Single graduates and those with a friend or relative living abroad were more likely to consider working abroad than were their counterparts (odds ratios were 2.3 and 1.7, respectively). The likelihood of considering working abroad decreased by 29% when the individuals' financial situation was improved. Factors associated with having a firm plan were previous professional experience in a foreign country, having someone abroad and financial improvement (5.4 times, 4.8 times and 2 times greater likelihood, respectively).

CONCLUSIONS

The high prevalence of intention to work abroad suggests the need to place the issue of the out-migration of nursing graduates on the policy agenda. College and specialty nursing graduates and health technicians are prepared to work abroad in search of a better quality of life, better working conditions and higher salaries.

Enhanced International Prognostic Index (NCCN-IPI), Charlson Comorbidity Index and absolute lymphocyte count as predictors for survival of elderly patients with diffuse large B cell lymphoma treated by immunochemotherapy

Diffuse large B cell lymphoma (DLBCL) affects more commonly patients over 60 years. These patients have vast number of comorbidities which can modify survival as well as other clinical parameters. The aim of this study was to evaluate prognostic significance of the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI), absolute lymphocyte count (ALC), absolute monocyte count (AMC), lymphocyte-to-monocyte ratio (LMR) and comorbidities expressed with Charlson Comorbidity Index (CCI). A total of 182 DLBCL patients 60 years old and older were included, focusing on whole group and patients older than 70. All patients were treated with immunochemotherapy.Overall treatment response was achieved in 84.6% of patients. The NCCN-IPI was of highly prognostic value in the analyzed group (p<0.0001). Survival analysis showed that ALC>1.1x109/L, AMC≤0.59x109/L, and LMR>2.8 were associated with more favorable outcome (p=0.029, p=0.019, p=0.028, respectively). The patients with CCI≥2 had poorer outcome (p=0.008) compared to the patients with CCI 0-1. Multivariate analysis showed that among ALC, AMC, LMR, NCCN-IPI and CCI, the NCCN-IPI was the critical parameter that significantly affected survival (p<0.0001). Furthermore, comorbidities were also valuable independent factors which influenced survival (p=0.031) as well as the ALC (p=0.024). In elderly DLBCL patients, NCCN-IPI and ALC proved their prognostic validity, while poorer outcome could be expected in older patients with high CCI (≥2). Furthermore, mentioned prognostic parameters retained their prognostic value in the group of patients older than 70.

Transcranial Doppler in brain death confirmation in clinical practice

PURPOSE

Transcranial Doppler (TCD) can be used as a confirmatory test in brain death. The aim was to present the usefulness of TCD in brain death confirmation.

MATERIALS AND METHODS

Forty-four patients with severe brain lesions leading to brain death were treated over a 4-year period. After the clinical diagnosis of brain death was made, the appropriate confirmatory test was chosen according to patient condition, taking into consideration the restrictions of the test protocol. Due to the inconclusive test results, some patients underwent repeat testing.

RESULTS

Among 44 patients, 19 had neurotrauma, 11 massive aneurysmal subarachnoidal hemorrhages, 1 arteriovenous subarachnoidal and parenchymal hemorrhage, 12 hypertensive parenchymal hemorrhages, and 1 ischemic stroke. As a primary test, TCD was used in 30, brain scintigraphy in 2, multislice CT angiography (CTA) in 10, and cerebral angiography in 2 patients, and the diagnosis was confirmed in 26, 3, 9 and 2 patients, respectively. Due to inconclusive results CTA was repeated in five patients. In patients in whom TCD was applied, the time to confirm the diagnosis was the shortest, and in most (61 %) cerebral circulatory arrest was confirmed within 2 hours of clinical diagnosis.

CONCLUSION

TCD is a favorable confirmatory test for cerebral circulatory arrest in brain death diagnosis.

Distinguishing Parkinson's disease and essential tremor with transcranial sonography

OBJECTIVES

Until today there is no reliable test that can clearly distinguish Parkinson's disease (PD) from the essential tremor (ET). Our aim was to determine the usefulness of the transcranial sonography (TCS) in the differential diagnosis of the PD and ET as well as the interobserver reliability for this method.

METHODS

Transcranial sonography of substantia nigra and clinical examination were performed on 80 PD patients, 30 ET patients, and 80 matched controls by two independent physicians.

RESULTS

Bilateral SN hyperechogenicity over the margin of 0.20 cm(2) was found in 91% of PD patients, 10% of healthy subjects, and in 13% patients with ET. Interobserver agreement for this method was significant (Student's t-test, P = 1.000).

CONCLUSIONS

Substantia nigra hyperechogenicity on TCS is a highly specific finding of PD, where in healthy individuals or in ET patients, it might correspond to an increased risk of developing PD later in life or might also be because of the impairment of nearby area of nucleus ruber in ET patients, as suggested by positron emission tomography studies. TCS may serve as a practical and sufficiently sensitive neuroimaging tool in PD diagnoses and in distinguishing it from ET; its repeatability and accuracy might add to its practical value.

Validation of test-day models for genetic evaluation of dairy goats in Norway

Test-day data for daily milk yield and fat, protein, and lactose content were sampled from the years 1988 to 2003 in 17 flocks belonging to 2 genetically well-tied buck circles. In total, records from 2,111 to 2,215 goats for content traits and 2,371 goats for daily milk yield were included in the analysis, averaging 2.6 and 4.8 observations per goat for the 2 groups of traits, respectively. The data were analyzed by using 4 test-day models with different modeling of fixed effects. Model [0] (the reference model) contained a fixed effect of year-season of kidding with regression on Ali-Schaeffer polynomials nested within the year-season classes, and a random effect of flock test-day. In model [1], the lactation curve effect from model [0] was replaced by a fixed effect of days in milk (in 3-d periods), the same for all year-seasons of kidding. Models [2] and [3] were obtained from model [1] by removing the fixed year-season of kidding effect and considering the flock test-day effect as either fixed or random, respectively. The models were compared by using 2 criteria: mean-squared error of prediction and a test of bias affecting the genetic trend. The first criterion indicated a preference for model [3], whereas the second criterion preferred model [1]. Mean-squared error of prediction is based on model fit, whereas the second criterion tests the ability of the model to produce unbiased genetic evaluation (i.e., its capability of separating environmental and genetic time trends). Thus, a fixed structure with year (year, year-season, or possibly flock-year) was indicated to appropriately separate time trends. Heritability estimates for daily milk yield and milk content were 0.26 and 0.24 to 0.27, respectively.

Aortic arch dissection presenting with hemodynamic spectrum of aortic regurgitation on transcranial Doppler

The diagnosis of aortic dissection is frequently missed at the time of hospital admittance. Neurological presentations are rare, and neuro-sonography is rarely used. We describe a patient with atypical clinical presentation of aortic arch dissection in whom neuro-sonological investigations showed a "cathedral like" haemodynamic spectrum of aortic regurgitation, directing the investigation towards the diagnosis.

Expression of hypoxia-inducible factor-1alpha in cervical carcinomas: correlation with tumor oxygenation

PURPOSE

To investigate the relations between hypoxia-inducible factor-1 (HIF-1), tumor oxygenation, and clinical correlates in patients with locally advanced carcinoma of the uterine cervix.

METHODS AND MATERIALS

Biopsies from 42 patients with invasive cervical carcinoma and previous polarographic O2 measurements were assessed for the expression of HIF-1alpha using digitized microscopic imaging and analysis.

RESULTS

The HIF-1alpha expression levels ranged from <0.1% to 10.7% of the total tumor area; the positive staining was localized exclusively to the nuclei. Three distinct arrangement patterns of HIF-1alpha-positive cells in relation to blood vessels were identified using spatial image mapping: (1) most HIF-1alpha-positive cells were located within the typical oxygen diffusion distance in tissue (< or =150 microm to the nearest blood vessel); (2) most HIF-1alpha-positive cells were located in the vicinity (< or =60 microm) of the blood vessels; and (3) no apparent spatial relationship was found between HIF-1alpha-positive cells and blood vessels. A statistically significant association was found between HIF-1alpha expression and tumor oxygenation (Spearman correlation coefficient = 0.4, p <0.01), as determined with the Eppendorf pO2 histograph. No correlation was found between the level of HIF-1alpha expression and patient outcome, using disease-free survival as the end point.

CONCLUSION

Our results suggest that HIF-1alpha expression may represent a useful biologic marker for hypoxia in uterine cervical cancer.

Multiparameter fluorescence mapping of nonprotein sulfhydryl status in relation to blood vessels and hypoxia in cervical carcinoma xenografts

PURPOSE

Aberrant architecture of the tumor vasculature and temporal fluctuations in blood flow can result in tumor hypoxia. The aim of this study was to classify tumor hypoxia based on distance to blood vessels, and to characterize its biologic significance by determining levels of nonprotein sulfhydryls (NPSH) in hypoxic regions located proximally and distally to tumor blood vessels.

METHODS AND MATERIALS

A dual fluorescence method was developed for the spatial colocalization of the vasculature and hypoxia in frozen sections from SiHa cervical carcinoma xenografts. A parallel section was stained with the sulfhydryl stain mercury orange. Composite fluorescence images were generated by imaging and tiling individual fields of view into 2D image arrays. Image arithmetic techniques were combined with feature-based image segmentation to characterize expression of NPSH as a function of the hypoxic tumor microenvironment.

RESULTS

NPSH levels were higher in hypoxic areas of the SiHa xenografts (15.1 +/- 0.5 vs. 13.5 +/- 0.5 integrated optical density [IOD], p < 0.03). When tumor hypoxia was classified by distance to the nearest visible blood vessel, significantly higher NPSH levels were found in hypoxic regions close to blood vessels than in regions at a distance from blood vessels.

CONCLUSION

The results of this study indicate differential expression of NPSH levels in regions of hypoxia that are proximal or distal to blood vessels in SiHa tumors.

Hypoxia-inducible factor-1alpha is an intrinsic marker for hypoxia in cervical cancer xenografts

The hypoxia-inducible factor 1 (HIF-1) is known to induce the expression of several proteins linked to the maintenance of oxygen homeostasis, cellular energy metabolism, and tumor progression. Its alpha subunit (HIF-1alpha) is stabilized under hypoxic conditions and, therefore, might represent an intrinsic marker for tissue hypoxia. Here we report on the spatial relationship between HIF-1alpha and the nitroimidazole hypoxia marker EF5 in cervical carcinoma xenografts, and on their spatial relationship to tumor blood vessels. EF5 was administered to mice bearing ME180 and SiHa cervical cancer xenografts. Frozen tumor tissue sections, triple-stained for HIF-1alpha, the endothelial cell marker CD31, and EF5, were imaged using wide-field multiparameter immunofluorescence microscopy. Expression levels of EF5 and HIF-1alpha were similar in ME180 xenografts, but the percentage of tumor area stained with EF5 was significantly smaller than the percentage of HIF-1alpha-positive area in SiHa tumors. In both tumor types the EF5-HIF-1alpha overlap was statistically significant, thus confirming their spatial and temporal colocalization. Spatial distribution analysis of EF5 and HIF-1alpha is consistent with different pO2 value "thresholds" for EF5 binding and HIF-1alpha expression. Summarized, our results indicate that HIF-1alpha is a useful intrinsic marker for hypoxia in cervical carcinoma xenografts.