Relevance of the Updated Recursive Partitioning Analysis (U-RPA) Classification in the Contemporary Care of Patients with Brain Metastases

Patients with brain metastases (BMETS) need information about the prognosis and potential value of treatment options to make informed therapeutic decisions, but tools to predict survival in contemporary practice are scarce. We propose an Updated Recursive Partitioning Analysis (U-RPA) instrument to predict survival and benefit from brain-directed treatment (BDT) of contemporary patients. This was a retrospective analysis of patients with BMETS treated between 2017 and 2019. With survival as the primary endpoint, we calculated the U-RPA and generated estimates using Kaplan-Meier curves and hazard ratios. Of 862 eligible patients, 752 received BDT and 110 received best supportive care (BSC). Median overall survival with BDT and BSC was 9.3 and 1.3 months, respectively. Patients in RPA class 1, 2A, 2B and 3 who underwent BDT had median survival of 28.1, 14.7, 7.6 and 3.3 months, respectively. The median survival for patients in RPA 3 who received BDT (n = 147), WBRT (n = 79) and SRS (n = 54) was 3.3, 2.9 and 4.1 months, respectively. The U-RPA defines prognosis estimates, independent of tumor type and treatment modality, which can assist to make value-based care treatment decisions. The prognosis for patients in U-RPA class 2B and 3 remains poor, with consideration for early palliative care involvement in these cases.

Alliance A071401: Phase II Trial of Focal Adhesion Kinase Inhibition in Meningiomas With Somatic NF2 Mutations

PURPOSE

Patients with progressive or recurrent meningiomas have limited systemic therapy options. Focal adhesion kinase (FAK) inhibition has a synthetic lethal relationship with NF2 loss. Given the predominance of NF2 mutations in meningiomas, we evaluated the efficacy of GSK2256098, a FAK inhibitor, as part of the first genomically driven phase II study in recurrent or progressive grade 1-3 meningiomas.

PATIENTS AND METHODS

Eligible patients whose tumors screened positively for NF2 mutations were treated with GSK2256098, 750 mg orally twice daily, until progressive disease. Efficacy was evaluated using two coprimary end points: progression-free survival at 6 months (PFS6) and response rate by Macdonald criteria, where PFS6 was evaluated separately within grade-based subgroups: grade 1 versus 2/3 meningiomas. Per study design, the FAK inhibitor would be considered promising in this patient population if either end point met the corresponding decision criteria for efficacy.

RESULTS

Of 322 patients screened for all mutation cohorts of the study, 36 eligible and evaluable patients with NF2 mutations were enrolled and treated: 12 grade 1 and 24 grade 2/3 patients. Across all grades, one patient had a partial response and 24 had stable disease as their best response to treatment. In grade 1 patients, the observed PFS6 rate was 83% (10/12 patients; 95% CI, 52 to 98). In grade 2/3 patients, the observed PFS6 rate was 33% (8/24 patients; 95% CI, 16 to 55). The study met the PFS6 efficacy end point both for the grade 1 and the grade 2/3 cohorts. Treatment was well tolerated; seven patients had a maximum grade 3 adverse event that was at least possibly related to treatment with no grade 4 or 5 events.

CONCLUSION

GSK2256098 was well tolerated and resulted in an improved PFS6 rate in patients with recurrent or progressive NF2-mutated meningiomas, compared with historical controls. The criteria for promising activity were met, and FAK inhibition warrants further evaluation for this patient population.

Clinical management of brain tumors in pregnancy

PURPOSE OF REVIEW

We review the diagnostic tools, treatment options, and clinical management for brain tumors diagnosed in pregnancy with consideration for management approaches that are best suited to preserve maternal and fetal health.

RECENT FINDINGS

Women of child-bearing age are at risk of developing brain tumors and are at increased risk compared with male counterparts for tumors that are hormonally driven. Brain tumors are rare neoplasms, and diagnosis of brain tumors in pregnancy is uncommon, such that management guidelines and treatment recommendations are lacking for most tumor types. We discuss the standard treatment options for brain tumors and the relative risks and safety when these treatments are considered during pregnancy. We review the neoplasms most commonly affecting pregnant women and the existing literature and guidelines.

SUMMARY

Pregnancy is a unique phase of life in which hormonal, immunologic, and vascular changes may impact tumor growth and presentation. Treatment decisions should consider the symptoms and stability of the pregnant patients, the gestational age and health of the fetus, and the location and behavior of the neoplasm.

CLRM-13 RELEVANCE OF RECURSIVE PARTITIONING ANALYSIS (RPA) CLASSIFICATION IN THE CURRENT CARE OF PATIENTS WITH BRAIN METASTASES (BMETS)

BACKGROUND

Patients diagnosed with BMETS want to know their prognosis and the benefit of treatment to make informed decisions. Clinician and patient biases frequently provide survival estimates that are too optimistic or pessimistic. We postulated that that RPA remains a useful tool to communicate prognosis and potential benefit from brain-directed treatment (BDT). We evaluated real-world data on RPA class and survival of patients with newly diagnosed BMETS from three academic institutions.

METHODS

We retrospectively reviewed the records of patients with BMETS between 2017 and 2019 who had at least 6 months of follow up. Excluded were patients with leptomeningeal or only dural/calvarial metastases. We calculated the RPA and according to class compared Kaplan-Meier survival curves.

RESULTS

We have data on 642 cases with median age of 65 years; 80% had lung, breast, melanoma, and renal as the primary cancer. Sixty (9.3%) patients received palliative care only, while 582 (90.7%) had BDT. The median survival of all patients according to RPA in months was 18.0 (I), 9.4 (II), and 2.4 (III) and for those receiving BDT (n=582), it was 19.2 (I), 11.2 (II), and 2.9 (III). There were statistically significant differences for BDT survival curves adjusted for multiple comparisons (I-II p=0.0124; II-III p<0.0001; I-III p<0.0001). For patients in RPA class III who received WBRT (n=62), the median survival was 2.9 months, and, for SRS (n=37), it was 3.5 months. We will present updated data including additional 238 cases and propose predictive/prognostic models based on our cohort that optimizes the RPA application in clinical practice.

CONCLUSION

In contemporary practice, the RPA classification remains significantly relevant in making care decisions for patients diagnosed with BMETS. Treatment recommendations for patients in RPA class III should be the result of multidisciplinary discussions with consideration for early palliative care involvement to de-escalate and avoid inefficacious BDT.

Clinical Reasoning: A 67-Year-Old Woman With Abdominal Pain, Constipation, and Urinary Retention

Meningeal melanocytomas are extremely rare, pigmented tumors of the CNS. They generally carry a favorable prognosis, although recurrence and transformation into the more aggressive malignant melanoma have been reported. We present a case of a patient who reported constipation and abdominal pain around the umbilicus, which progressed into cord compression with lower extremity weakness and gait instability. Spinal MRI revealed a tumor at the level of T11, and she underwent gross total resection of the mass. Pathology demonstrated a meningeal melanocytoma with intermediate features. She received postoperative radiation therapy and had stable disease for 3 years, at which time she developed new weakness and drop metastases. This case represents a rare presentation of a rare disease, in which a spinal cord tumor presented with constipation and abdominal distress. Intradural extramedullary tumors of the thoracic spine are most commonly nerve sheath tumors or meningiomas, but rare entities such as melanocytomas can present in this location; even more rarely, these tumors can have an aggressive course with delayed recurrence.

Coping with glioblastoma: prognostic communication and prognostic understanding among patients with recurrent glioblastoma, caregivers, and oncologists

PURPOSE

Glioblastoma (GBM) is a devastating neuro-oncologic disease with invariably poor prognosis. Despite this, research shows patients have unrealistic perceptions of their prognosis, which may relate in part to communication patterns between patients, caregivers and oncologists. The purpose of this study was to examine communication processes and goals among patients, caregivers, and oncologists to elucidate drivers of prognostic understanding (PU) in the context of recurrent GBM.

METHODS

This was a prospective, multi-center study enrolling adult patients with GBM, caregivers, and oncologists, who independently reported the content of a specific discussion involving the disclosure of GBM recurrence. Communication processes and goals were characterized for each participant, and concordance between all dyads and patient-caregiver-oncologist triads were calculated.

RESULTS

Seventeen patient, caregiver, and oncologist triads were analyzed. At the individual level, three (17.6%) patients and 8 (47.1%) caregivers reported having discussed prognosis during the clinical encounter, as compared to ten oncologists (58.8%). Seven patients (41.2%) and 5 caregivers (29.4%), versus thirteen oncologists (76.5%) reported ever discussing prognosis or life expectancy at previous appointments. Generally, patient-caregiver concordance (i.e., both answered the same) regarding communication goals and processes was low. Triads showed limited concordant responses in discussing curability (n = 5), prognosis (n = 4), end-of-life treatment goals (n = 4), and ever discussing prognosis (n = 3).

CONCLUSION

Patients, caregivers and oncologists had discordant views regarding communication processes and prognostic goals, even when recalling a single discussion. This study highlights the importance of clear and frequent communication about prognosis, and the need for further research on communication and PU in the neuro-oncology setting.

Cancer Care in the Wake of a Cyberattack: How to Prepare and What to Expect

PURPOSE

Cyberattacks targeting health care organizations are becoming more frequent and affect all aspects of care delivery. Cancer care is particularly susceptible to major disruptions because of the potential of immediate and long-term consequences for patients who often rely on timely diagnostic testing and regular administration of systemic therapy in addition to other local treatment modalities to cure or control their diseases. On October 28, 2020, a cyberattack was launched on the University of Vermont Health Network with wide-ranging consequences for oncology, including loss of access to all network intranet servers, e-mail communications, and the electronic medical record (EMR).

METHODS

This review details the immediate challenges faced by hematology and oncology during the cyberattack. The impact and response on inpatient, outpatient, and special patient populations are described. Steps that other academic- and community-based oncology practices can take to lessen the brunt of such an assault are suggested.

RESULTS

The two areas of immediate impact after the cyberattack were communications and lack of EMR access. The oncology-specific impact included loss of the individualized EMR chemotherapy plan templates and electronic safeguards built into multistep treatment preparation and delivery. With loss of access to schedules, basic patient information, encrypted communications platforms and radiology, and laboratory and pharmacy services, clinical outpatient care delivery was reduced by 40%. The infusion visit volume dropped by 52% in the first week and new patients could not access necessary services for timely diagnostic evaluation, requiring the creation of command centers to oversee ethical and transparent triage and allocation of systemic therapies and address new patient referrals. This included appropriate transfer of patients to alternate sites to minimize delays. Inpatient care including transitions of care was particularly challenging and addressing patient populations whose survival might be affected by delays in care.

CONCLUSION

Oncology health care leaders and providers should be aware of the potential impact of a cyberattack on cancer care delivery and preventively develop processes to mitigate the impact.

Multifocal metastases to choroid plexus from papillary thyroid carcinoma: illustrative case

BACKGROUND

Choroid plexus metastases are extremely rare from all types of malignancy, with only 42 cases reported in the literature thus far. Most of these originate from renal cell carcinoma and present as a solitary choroid plexus lesion; only two cases of multifocal choroid plexus metastases have been reported to date.

OBSERVATIONS

The authors report the third case of multifocal metastases to the choroid plexus, that of a 75-year-old man who developed three measurable choroid plexus lesions approximately 3.5 years after undergoing total thyroidectomy and chemotherapy for papillary thyroid carcinoma. He underwent intraventricular biopsy of the largest lesion and subsequently died of hydrocephalus after opting for comfort care only.

LESSONS

This is the third case of multifocal choroid plexus metastasis in the literature and the second case of multifocal metastasis from thyroid carcinoma. As such, the natural disease course is not well characterized. This case is compared with the previous eight reports of choroid plexus metastases from thyroid carcinoma, seven of which involved solitary lesions. The eight prior cases are evaluated with attention to treatment modalities used and factors potentially influencing prognosis, specifically those that might contribute to hydrocephalus, a reported complication for this pathology.

Safety of apixaban for venous thromboembolic primary prophylaxis in patients with newly diagnosed malignant glioma

The cumulative incidence of symptomatic venous thromboembolism (VTE) among patients with malignant gliomas (MG) is estimated to be as high as 36% during the course of therapy. Development of VTE is associated with an increased risk of hospitalization, delays in cancer treatment, and an increased risk of complications including intracranial hemorrhage as well as VTE specific symptoms. Despite the high risk of VTE and associated morbidity, there is no standard recommendations regarding long term outpatient VTE prophylaxis in patients with MG due to the lack of clinical trial evidence in this patient population. In this study, we treated ten patients with newly diagnosed MG with apixaban, 2.5 mg twice daily beginning 2-21 days after craniotomy and continuing for up to 6 months. Unacceptable toxicity was defined by ≥ grade 2 CNS or non-CNS hemorrhage, a thromboembolic event (i.e. stroke) or cardiovascular event requiring anticoagulation or anti-platelet therapy. There were no unacceptable toxicities to report and no treatment-related adverse events. None of the patients on the study were diagnosed with a VTE while receiving apixaban. We conclude that apixaban can be given safely to patients with primary MG shortly after craniotomy and should be considered for VTE prevention in these high-risk patients.

SNO 2020 diversity survey: defining demographics, racial biases, career success metrics and a path forward for the field of neuro-oncology

BACKGROUND

Neuro-oncology has grown tremendously since 2010, marked by increasing society membership, specialized clinical expertise, and new journals. Yet, modest improvement in racial/ethnic diversity amongst clinical trial participants, researchers and clinicians led us to conduct a survey to identify opportunities to enhance diversity and inclusiveness amongst neuro-oncology professionals.

METHODS

In summer 2020, the Women and Diversity Committee of the Society for Neuro-Oncology (SNO) distributed an anonymous online survey to members and affiliates including European Association of Neuro-Oncology (EANO), Asian Society for Neuro-Oncology (ASNO), Society for Neuro-Oncology Latin America (SNOLA) and Society for Neuro-Oncology Sub-Saharan Africa (SNOSSA). The survey captured personal and professional characteristics, biases, effective mentorship qualities, career service metrics and suggested field/society changes. Results were analyzed by geography, profession, age, racial/ethnic and sexual identity. Standard descriptive statistics characterized the study population.

RESULTS

The 386 respondents were predominantly female (58%) with a median age range of 40-49 years (31%), White (65%), and SNO members (97%). Most worked in North America (77%) in a research profession (67%). A majority of White respondents reported never experiencing biases (64%), while the majority of non-White respondents reported unconscious biases/microaggressions, followed by a lack of/limited mentorship. Qualitative assessments showcased that personal/professional success metrics were linked to needed improvements in diversity and inclusion efforts within the neuro-oncology field.

CONCLUSIONS

The prevalence of racial/ethnic biases and poor mentorship rates amongst underrepresented groups in neuro-oncology is high and potentially linked to the limited diverse representation amongst members and affiliates. These findings warrant a swift implementation of equity and inclusion practices within the neuro-oncology field.

The state of neuro-oncology during the COVID-19 pandemic: a worldwide assessment

Background

It remains unknown how the COVID-19 pandemic has changed neuro-oncology clinical practice, training, and research efforts.

Methods

We performed an international survey of practitioners, scientists, and trainees from 21 neuro-oncology organizations across 6 continents, April 24-May 17, 2020. We assessed clinical practice and research environments, institutional preparedness and support, and perceived impact on patients.

Results

Of 582 respondents, 258 (45%) were US-based and 314 (55%) international. Ninety-four percent of participants reported changes in their clinical practice. Ninety-five percent of respondents converted at least some practice to telemedicine. Ten percent of practitioners felt the need to see patients in person, specifically because of billing concerns and pressure from their institutions. Sixty-seven percent of practitioners suspended enrollment for at least one clinical trial, including 62% suspending phase III trial enrollments. More than 50% believed neuro-oncology patients were at increased risk for COVID-19. Seventy-one percent of clinicians feared for their own personal safety or that of their families, specifically because of their clinical duties; 20% had inadequate personal protective equipment. While 69% reported increased stress, 44% received no psychosocial support from their institutions. Thirty-seven percent had salary reductions and 63% of researchers temporarily closed their laboratories. However, the pandemic created positive changes in perceived patient satisfaction, communication quality, and technology use to deliver care and mediate interactions with other practitioners.

Conclusions

The pandemic has changed treatment schedules and limited investigational treatment options. Institutional lack of support created clinician and researcher anxiety. Communication with patients was satisfactory. We make recommendations to guide clinical and scientific infrastructure moving forward and address the personal challenges of providers and researchers.

Benign and malignant tumors of the central nervous system and pregnancy

Tumors of the central nervous system (CNS) are rare entities, typically affecting the very young or the very old, but span a spectrum of disease that may present in any age group. Women of reproductive age are more likely to be affected by benign tumors, including pituitary adenomas and meningiomas, and aggressive intracranial malignancies, such as brain metastases and glioblastoma, rarely present in pregnancy. Definitive management of CNS tumors may involve multimodal therapy, including surgery, radiation, and chemotherapy, and each of these treatments carries risk to the mother and developing fetus. CNS tumors often present with challenging and morbid symptoms such as headache and seizure, which need to be managed throughout a pregnancy. Decisions about timing treatment during pregnancy or delaying until after delivery, continuing or electively terminating a pregnancy, and future family planning and fertility are complex and require a multidisciplinary care team to evaluate the implications to both mother and baby. There are no guidelines or consensus recommendations regarding brain tumor management in pregnancy, and thus, individual treatment decisions are made by the care team based on experiential evidence, extrapolation of guidelines for nonpregnant patients, and patient values and preferences.

Intradural cauda equina Candida abscess presenting with hydrocephalus: case report

Central nervous system (CNS) candida infections are often associated with a poor prognosis. Typically, CNS candidiasis presents as meningitis or microabscesses. Here, the authors report a patient with a challenging presentation of a CNS Candida infection as a discrete, large cauda equina abscess. The patient initially presented with ventriculomegaly due to fourth ventricular outflow obstruction and a cauda equina mass. The patient was treated with a ventriculoperitoneal shunt and underwent a lumbar laminectomy for exploration of the lumbar lesion. An intradural abscess was encountered during surgery. Fungal wet mount revealed fungal elements and polymerase chain reaction confirmed the presence of Candida albicans. The patient did not have any known predisposition to fungal infections; therefore, the authors performed whole-exome sequencing using peripheral blood mononuclear cell DNA. They found heterozygous missense variants in the following genes: colony-stimulating factor 2 (CSF2) and Ras protein-specific guanine nucleotide-releasing factor 1 (RASGRF1)-genes that have been specifically associated with protection from CNS candidiasis via caspase recruitment domain-containing protein 9 (CARD9) signaling, and phospholipase C gamma 2 (PLCG2)-a lectin receptor involved in candidiasis. The authors' experience suggests that C. albicans can present as a cauda equina abscess. Hydrocephalus, a result of diffuse arachnoiditis, is a potential complication from intradural fungal abscesses.

Fungal cauda equina lesion with delayed cord compression and treatment response

This is a 24 year old man with profound chronic hydrocephalus found to have a cauda equina abscess composed of Candida albicans. Prior literature reveals a paucity of central nervous system candidiasis. In these previously reported cases, there was evidence of local invasion of surrounding structures; however, this case is a sentinel report of a fungal abscess without evidence of local structural invasion. The patient's course was complicated by clinical and radiographic worsening to cauda equina syndrome, requiring emergent surgical decompression, despite appropriate antifungal treatment. This case illustrates the diagnostic challenge of this rare entity and the need for close follow up with this patient population.

Multicenter phase II study of temozolomide and myeloablative chemotherapy with autologous stem cell transplant for newly diagnosed anaplastic oligodendroglioma

Background

Anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) are chemotherapy-sensitive tumors with prolonged survival after radiochemotherapy. We report a prospective trial using induction temozolomide (TMZ) followed by myeloablative high-dose chemotherapy (HDC) with autologous stem-cell transplant (ASCT) as a potential strategy to defer radiotherapy.

Methods

Patients with AO/AOA received 6 cycles of TMZ (200 mg/m2 × 5/28 day). Responding patients were eligible for HDC (thiotepa 250 mg/m2/day × 3 days, then busulfan 3.2 mg/kg/day × 3 days), followed by ASCT. Genomic characterization was performed using next-generation sequencing.

Results

Forty-one patients were enrolled; 85% had 1p/19q codeleted tumors. After induction, 26 patients were eligible for HDC-ASCT and 21 agreed to proceed. There were no unexpected adverse events or toxic deaths. After median follow-up of 66 months, 2-year progression-free survival (PFS) for transplanted patients was 86%, 5-year PFS 60%, and no patient has died. Among all 1p/19q codeleted patients (N = 33), 5-year PFS was 50% and 5-year overall survival (OS) 93%, with median time to radiotherapy not reached. Next-generation sequencing disclosed typical oligodendroglioma-related mutations, including IDH1, TERT, CIC, and FUBP1 mutations in 1p/19q codeleted patients, and glioblastoma-like signatures in 1p/19q intact patients. Aside from IDH1, potentially oncogenic/actionable mutations were variable, depicting wide molecular heterogeneity within oligodendroglial tumors.

Conclusions

TMZ followed by HDC-ASCT can be safely administered to patients with newly diagnosed 1p/19q codeleted AO. This strategy was associated with promising PFS and OS, suggesting that a chemotherapy-based approach may delay the need for radiotherapy and radiation-related toxicities. Raw data for further genomic and meta-analyses are publicly available at http://cbioportal.org/study?id=odg_msk_2017, accessed 6 January 2017.

Clinicaltrials.gov registry

NCT00588523.

Neuromuscular complications of immune checkpoint inhibitor therapy

Immune checkpoint inhibitor (ICPI) therapy unleashes the body's natural immune system to fight cancer. ICPIs improve overall cancer survival, however, the unbridling of the immune system may induce a variety of immune-related adverse events. Neuromuscular immune complications are rare but they can be severe. Myasthenia gravis and inflammatory neuropathy are the most common neuromuscular adverse events but a variety of others including inflammatory myopathy are reported. The pathophysiologic mechanism of these autoimmune disorders may differ from that of non-ICPI-related immune diseases. Accordingly, while the optimal treatment for ICPI-related neuromuscular disorders generally follows a traditional paradigm, there are important novel considerations in selecting appropriate immunosuppressive therapy. This review presents 2 new cases, a summary of neuromuscular ICPI complications, and an approach to the diagnosis and treatment of these disorders. Muscle Nerve, 2018.

Ibrutinib Unmasks Critical Role of Bruton Tyrosine Kinase in Primary CNS Lymphoma

Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B. CD79B-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in CD79B-mutant PCNSL cells.Significance: Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in CD79B-mutant human PCNSLs. Cancer Discov; 7(9); 1018-29. ©2017 AACR.See related commentary by Lakshmanan and Byrd, p. 940This article is highlighted in the In This Issue feature, p. 920.

Immune modulation associated with vascular endothelial growth factor (VEGF) blockade in patients with glioblastoma

BACKGROUND

Vascular endothelial growth factor (VEGF), in addition to being pro-angiogenic, is an immunomodulatory cytokine systemically and in the tumor microenvironment. We previously reported the immunomodulatory effects of radiation and temozolomide (TMZ) in newly diagnosed glioblastoma. This study aimed to assess changes in peripheral blood mononuclear cell (PBMC) populations, plasma cytokines, and growth factor concentrations following treatment with radiation, TMZ, and bevacizumab (BEV).

METHODS

Eleven patients with newly diagnosed glioblastoma were treated with radiation, TMZ, and BEV, following surgery. We measured immune-related PBMC subsets using multi-parameter flow cytometry and plasma cytokine and growth factor concentrations using electrochemiluminescence-based multiplex analysis at baseline and after 6 weeks of treatment.

RESULTS

The absolute number of peripheral blood regulatory T cells (Tregs) decreased significantly following treatment. The lower number of peripheral Tregs was associated with a CD4+ lymphopenia, and thus, the ratio of Tregs to PBMCs was unchanged. The addition of bevacizumab to standard radiation and temozolomide led to the decrease in the number of circulating Tregs when compared with our prior study. There was a significant decrease in CD8+ cytotoxic and CD4+ recent thymic emigrant T cells, but no change in the number of myeloid-derived suppressor cells. Significant increases in plasma VEGF and placental growth factor (PlGF) concentrations were observed.

CONCLUSIONS

Treatment with radiation, TMZ, and BEV decreased the number but not the proportion of peripheral Tregs and increased the concentration of circulating VEGF. This shift in the peripheral immune cell profile may modulate the tumor environment and have implications for combining immunotherapy with anti-angiogenic therapy.

Diagnostic Accuracy of T1-Weighted Dynamic Contrast-Enhanced-MRI and DWI-ADC for Differentiation of Glioblastoma and Primary CNS Lymphoma

BACKGROUND AND PURPOSE

Glioblastoma and primary CNS lymphoma dictate different neurosurgical strategies; it is critical to distinguish them preoperatively. However, current imaging modalities do not effectively differentiate them. We aimed to examine the use of DWI and T1-weighted dynamic contrast-enhanced-MR imaging as potential discriminative tools.

MATERIALS AND METHODS

We retrospectively reviewed 18 patients with primary CNS lymphoma and 36 matched patients with glioblastoma with pretreatment DWI and dynamic contrast-enhanced-MR imaging. VOIs were drawn around the tumor on contrast-enhanced T1WI and FLAIR images; these images were transferred onto coregistered ADC maps to obtain the ADC and onto dynamic contrast-enhanced perfusion maps to obtain the plasma volume and permeability transfer constant. Histogram analysis was performed to determine the mean and relative ADC_mean and relative 90th percentile values for plasma volume and the permeability transfer constant. Nonparametric tests were used to assess differences, and receiver operating characteristic analysis was performed for optimal threshold calculations.

RESULTS

The enhancing component of primary CNS lymphoma was found to have significantly lower ADC_mean (1.1 × 10^-3 versus 1.4 × 10^-3; P < .001) and relative ADC_mean (1.5 versus 1.9; P < .001) and relative 90th percentile values for plasma volume (3.7 versus 5.0; P < .05) than the enhancing component of glioblastoma, but not significantly different relative 90th percentile values for the permeability transfer constant (5.4 versus 4.4; P = .83). The nonenhancing portions of glioblastoma and primary CNS lymphoma did not differ in these parameters. On the basis of receiver operating characteristic analysis, mean ADC provided the best threshold (area under the curve = 0.83) to distinguish primary CNS lymphoma from glioblastoma, which was not improved with normalized ADC or the addition of perfusion parameters.

CONCLUSIONS

ADC was superior to dynamic contrast-enhanced-MR imaging perfusion, alone or in combination, in differentiating primary CNS lymphoma from glioblastoma.

T1-Weighted Dynamic Contrast-Enhanced MRI as a Noninvasive Biomarker of Epidermal Growth Factor Receptor vIII Status

BACKGROUND AND PURPOSE

Epidermal growth factor receptor variant III is a common mutation in glioblastoma, found in approximately 25% of tumors. Epidermal growth factor receptor variant III may accelerate angiogenesis in malignant gliomas. We correlated T1-weighted dynamic contrast-enhanced MR imaging perfusion parameters with epidermal growth factor receptor variant III status.

MATERIALS AND METHODS

Eighty-two consecutive patients with glioblastoma and known epidermal growth factor receptor variant III status who had dynamic contrast-enhanced MR imaging before surgery were evaluated. Volumes of interest were drawn around the entire enhancing tumor on contrast T1-weighted images and then were transferred onto coregistered dynamic contrast-enhanced MR imaging perfusion maps. Histogram analysis with normalization was performed to determine the relative mean, 75th percentile, and 90th percentile values for plasma volume and contrast transfer coefficient. A Wilcoxon rank sum test was applied to assess the relationship between baseline perfusion parameters and positive epidermal growth factor receptor variant III status. The receiver operating characteristic method was used to select the cutoffs of the dynamic contrast-enhanced MR imaging perfusion parameters.

RESULTS

Increased relative plasma volume and increased relative contrast transfer coefficient parameters were both significantly associated with positive epidermal growth factor receptor variant III status. For epidermal growth factor receptor variant III-positive tumors, relative plasma volume mean was 9.3 and relative contrast transfer coefficient mean was 6.5; for epidermal growth factor receptor variant III-negative tumors, relative plasma volume mean was 3.6 and relative contrast transfer coefficient mean was 3.7 (relative plasma volume mean, P < .001, and relative contrast transfer coefficient mean, P = .008). The predictive powers of relative plasma volume histogram metrics outperformed those of the relative contrast transfer coefficient histogram metrics (P < = .004).

CONCLUSIONS

Dynamic contrast-enhanced MR imaging shows greater perfusion and leakiness in epidermal growth factor receptor variant III-positive glioblastomas than in epidermal growth factor receptor variant III-negative glioblastomas, consistent with the known effect of epidermal growth factor receptor variant III on angiogenesis. Quantitative evaluation of dynamic contrast-enhanced MR imaging may be useful as a noninvasive tool for correlating epidermal growth factor receptor variant III expression and related tumor neoangiogenesis. This potential may have implications for monitoring response to epidermal growth factor receptor variant III-targeted therapies.

Essential competencies in palliative medicine for neuro-oncologists

Palliative care is an approach to practicing medicine that addresses symptom management, alleviation of pain, assessment of psychosocial and spiritual distress or suffering, and practical support for patients and their caregivers with a goal of improving quality of life for patients with serious and life-threatening illnesses. Although palliative care has gained acceptance as an important part of comprehensive cancer care at the end of life, early integration of palliative care is less common. Patients with high-grade malignant gliomas have an invariably poor prognosis and high morbidity. With short survival times and complex neurological and systemic symptoms, these patients require palliative care from the time of diagnosis. In this review, we highlight the palliative care needs of neuro-oncology patients at diagnosis, during treatment, and at the end of life. We identify some of the barriers to incorporation of palliative care in standard neuro-oncology practice and equate competency in neuro-oncology with competency in the basic tenets of palliative medicine.

Emerging therapies for glioblastoma

IMPORTANCE

Glioblastoma is the most common primary malignant brain tumor, but despite multimodal treatment with surgery, radiotherapy, and temozolomide chemotherapy, the prognosis is poor, with a median survival of 16 to 19 months and poor quality of life throughout the disease course. New treatments are needed.

EVIDENCE REVIEW

Articles were identified through a search of PubMed references from March 2005 through January 2014, using the terms glioblastoma, glioma, malignant glioma, and brain neoplasm, as well as by search of the authors' files. Clinical trials were identified in the Clinicaltrials.gov registry.

FINDINGS

Advances in the understanding of the molecular biology of glioblastoma are being rapidly translated into innovative clinical trials, capitalizing on improved genomic, epigenetic, transcriptional, and proteomic characterization of glioblastomas as well as host factors, including the brain microenvironment and immune system interactions. Therapies targeting tumor growth factor receptors and downstream pathways, angiogenesis, modulation of cancer stemlike cells, cell cycle regulation, oncolytic viruses, new radiotherapy techniques, and immunotherapy, including vaccines and modulation of immune checkpoints (eg, programmed cell death 1 and cytotoxic T-lymphocyte antigen 4), are under investigation. In addition to novel agents, techniques to circumvent the blood-brain barrier to facilitate central nervous system drug exposure are being developed.

CONCLUSIONS AND RELEVANCE

Glioblastoma is an aggressive tumor with heterogeneous molecular features and complex host interactions, many of which are amenable to therapeutic intervention. Meaningful treatment advances will depend on identifying agents that target mechanistic vulnerabilities that are relevant to specific subgroups of patients; increasing patient enrollment into clinical trials is essential to accelerate the development of patient-tailored treatments.

Regulatory T cells are not a strong predictor of survival for patients with glioblastoma

BACKGROUND

Regulatory T cells (Tregs) are potentially prognostic indicators in patients with glioblastoma. If differences in frequency of Tregs in tumor or blood account for substantial variation in patient survival, then reliably measuring Tregs may enhance treatment selection and improve outcomes.

METHODS

We measured Tregs and CD3+ T cells in tumors and blood from 25 patients with newly diagnosed glioblastoma. Tumor-infiltrating Tregs and CD3+ T cells, measured by quantitative DNA demethylation analysis (epigenetic qPCR) and by immunohistochemistry, and peripheral blood Treg proportions measured by flow cytometry were correlated with patient survival. Additionally, we analyzed data from The Cancer Genome Atlas (TCGA) to correlate the expression of Treg markers with patient survival and glioblastoma subtypes.

RESULTS

Tregs, as measured in tumor tissue and peripheral blood, did not correlate with patient survival. Although there was a correlation between tumor-infiltrating Tregs expression by epigenetic qPCR and immunohistochemistry, epigenetic qPCR was more sensitive and specific. Using data from TCGA, mRNA expression of Forkhead box protein 3 (FoxP3) and Helios and FoxP3 methylation level did not predict survival. While the classical glioblastoma subtype corresponded to lower expression of Treg markers, these markers did not predict survival in any of the glioblastoma subtypes.

CONCLUSIONS

Although immunosuppression is a hallmark of glioblastoma, Tregs as measured in tissue by gene expression, immunohistochemistry, or demethylation and Tregs in peripheral blood measured by flow cytometry do not predict survival of patients. Quantitative DNA demethylation analysis provides an objective, sensitive, and specific way of identifying Tregs and CD3+ T cells in glioblastoma.

Diagnosis of probable psychogenic nonepileptic seizures in the outpatient clinic: does gender matter?

Psychogenic nonepileptic seizures (PNESs) are paroxysmal events of altered behavior that outwardly resemble epilepsy but are caused by psychiatric disease. The diagnosis of probable PNESs can be made in the outpatient clinic prior to video-EEG monitoring by identification of specific PNES predictors and specific elements of seizure semiology from the clinical history. Since psychiatric disease may have distinct mechanisms between women and men, the objective of this study was to determine if gender-specific differences exist in PNES predictors and PNES semiology. Such differences could be used to optimize the accuracy of outpatient diagnosis of probable PNESs. Medical records of male and female patients with video-EEG diagnosis of definite PNESs were retrospectively reviewed for occurrence of PNES predictors. In addition, PNES semiology was analyzed de novo from video-EEG records and categorized into previously established semiology clusters. Eighty-six patients were included in the analysis (59 women and 27 men). We found significantly lower rates of reported physical and sexual abuse, lower rates of previous psychiatric diagnosis, and lower rates of chronic pain in male patients with no significant differences in rates of other PNES predictors. Furthermore, we found no difference in PNES semiology between men and women, with both groups experiencing similar rates of major motor, minor motor, and nonmotor semiology. In conclusion, our results lend support to the idea that distinct risk factor criteria but similar semiology criteria should be used for the diagnosis of probable PNESs in the outpatient clinic in men and women.

Vaccine-based immunotherapy for glioblastoma

Glioblastoma remains the most lethal human brain tumor, despite the advent of multimodal treatment approaches. Because immune tolerance plays an important role in tumor progression, adding immunotherapy has become an attractive and innovative treatment approach for these aggressive tumors. Several early-phase clinical trials have demonstrated that vaccine-based immunotherapies, including dendritic cell therapy, peptide-based vaccines and vaccines containing autologous tumor lysates, are feasible and well tolerated. These trials have revealed promising trends in overall survival and progression-free survival for patients with glioblastoma, and have paved the way for ongoing randomized controlled trials.

Immunotherapy for the treatment of glioblastoma

Glioblastoma, the most aggressive primary brain tumor, thrives in a microenvironment of relative immunosuppression within the relatively immune-privileged central nervous system. Despite treatments with surgery, radiation therapy, and chemotherapy, prognosis remains poor. The recent success of immunotherapy in the treatment of other cancers has renewed interest in vaccine therapy for the treatment of gliomas. In this article, we outline various immunotherapeutic strategies, review recent clinical trials data, and discuss the future of vaccine therapy for glioblastoma.

An alternative method of endotracheal intubation of common marmosets (Callithrix jacchus)

Endotracheal intubation was carried out in 11 common marmosets (Callithrix jacchus). A commercially available tilting stand and a Miller laryngoscope blade were used to visualize the larynx. Anaesthesia was induced with alphaxalone (10.6 ± 1.6 mg/kg intramuscularly, followed by 3.2 ± 1.2 mg/kg intravenously). The diameter of the proximal trachea easily fitted an endotracheal tube made from readily available material (a 12 G 'over the needle' catheter). Once the tip of the endotracheal tube was at the level of the vocal folds, the tube had to be gently rotated through a 180° angle in order to pass through the larynx into the trachea. Assessment of the dimensions of the larynx and trachea, and comparison with external anatomical features of the animals (n = 10) showed that the length of the trachea could be predicted by multiplying the craniosacral length of the marmoset by a factor of 0.42.

Benign prostatic hyperplasia presenting with renal failure--what is the role for transurethral resection of the prostate (TURP)?

The aim of the study was to determine the role of transurethralresection of prostate (TURP) in normalising renal function in men presenting with obstructive renal failure secondary to benign prostatic hyperplasia. We reviewed the cases of 14 men who presented in the last 5 years with renal impairment associated with symptoms of bladder outflow obstruction and radiological evidence of obstructive uropathy. The mean serum creatinine at presentation was 632 ng/mL (range 1299 - 225). The mean age at presentation was 68.2 years (range 50 - 83 years). Duration of symptoms prior to presentation ranged between 1 - 118 months (mean 21.5 months). Following catheter insertion, all patients underwent TURP. Six of the 14 patients required dialysis prior to surgery. Histology of the resected prostate confirmed benign prostatic hypertrophy and/or hyperplasia in all cases. Patients with carcinoma of the prostate were excluded from the study. Following TURP, 2 of the 14 men (14%) failed to void spontaneously following removal of catheter - one patient performs clean self intermittent catheterization (CSIC), the other man has an in-dwelling catheter in situ. One patient died 7 months following TURP due to a myocardial infarction. However, 8 patients, (57%) remained dialysis dependent following TURP. Two of these patients have since undergone successful renal transplantation. Of the remaining 6 patients, only 3 have normal renal function with the other 3 experiencing moderately elevated serum creatinine (range 236 - 344 ng/mL). In patients presenting with renal failure due to bladder outflow obstruction, TURP restores normal voiding pattern in many cases. However renal failure due to bladder outflow obstruction tends to be more refractory and only 3 of 14 patients experienced return to normal renal function post treatment.

Renal artery aneurysm treated with ex vivo repair and autotransplantation

Renal artery aneurysms are being encountered more frequently due to a wider use of angiography. As the risk of rupture is unclear, the indications for surgery remain controversial. Despite advances in treatment, complex aneurysms often require nephrectomy for adequate excision. We report a case of an incidentally diagnosed renal artery aneurysm successfully treated with extracorporeal repair and autotransplantation. Ex vivo repair and renal autotransplantation is a safe and effective treatment for the management of complex renal artery aneurysms

Emphysematous cystitis in an elderly patient with ulcerative colitis

Emphysematous cystitis is a rare complication of lower urinary tract infections. The disease is characterized by air within the bladder wall and lumen and commonly occurs in middle-aged diabetic women. Intramural bladder gas seen on imaging is pathognomonic for this condition. The severity of the illness varies widely from cases diagnosed incidentally to patients presenting with life-threatening sepsis. We report the case of an 80-year-old non-diabetic man presenting with emphysematous cystitis after a total colectomy for ulcerative colitis.

Traumatic pseudoaneurysm of the internal carotid artery presenting with oculosympathetic palsy

BACKGROUND

Blunt internal carotid artery (ICA) injury is rare but undiagnosed can have disastrous clinical consequences.

AIM

To report a late presentation of blunt ICA injury in a young male following a road traffic accident.

RESULT

A 16-year-old male presented 11 days following a head injury with a unilateral Horner's syndrome. Imaging confirmed a pseudoaneurysm of the ICA. The patient was treated with anticoagulant therapy.

CONCLUSION

Diagnosis of ICA injury requires a high index of suspicion and presentation with unusual neurological signs following blunt trauma to the head and neck requires prompt investigation.

The effects of Neotrofin on septodentate sprouting after unilateral entorhinal cortex lesions in rats

PURPOSE

Recent research on the purine derivative of hypoxanthine Neotrofin (4-[[3-(1,6-dihydro-6-oxo-9-purin-9-yl)-1-oxopropyl]amino]benzoic acid; AIT-082) has indicated that Neotrofin treatment elevates the mRNA levels of various neurotrophic factors, including nerve growth factor (NGF), in the CNS. Several previous studies have indicated that NGF may regulate septodentate sprouting after entorhinal cortex lesions in rats. Thus, the objective of this investigation was to determine whether Neotrofin treatment would enhance lesion-induced septodentate sprouting from 4 to 15 days postlesion.

METHODS

Sham-operated rats or rats with EC lesions were injected (i.p.) with either Neotrofin (30 mg/kg) or saline (0.9%) immediately after surgery and every day thereafter until the end of the treatment regimen. Septodentate sprouting, as indicated by intensity of acetylcholinesterase (AChE) label in the dentate gyrus, was assessed with optical densitometry.

RESULTS

We observed that Neotrofin elevated the AChE-label in the outer molecular layer of the ventral dentate gyrus at 4 days postlesion and of the dorsal dentate gyrus at 15 days postlesion.

CONCLUSIONS

Neotrofin appears to have exerted limited stimulatory effects on lesion-induced sprouting by a cholinergic pathway.

The major messenger ribonucleoprotein particle protein p50 (YB-1) promotes nucleic acid strand annealing

p50, a member of the Y-box binding transcription factor family, is tightly associated with eukaryotic mRNAs and is responsible for general translational regulation. Here we show that p50, in addition to its previously described ability to melt mRNA secondary structure, is capable of promoting rapid annealing of complementary nucleic acid strands. p50 accelerates annealing of RNA and DNA duplexes up to 1500-fold within a wide range of salt concentrations and temperatures. Phosphorylation of p50 selectively inhibits DNA annealing. Moreover, p50 catalyzes strand exchange between double-stranded and single-stranded RNAs yielding a product bearing a more extended double-stranded structure. Strikingly, p50 displays both RNA-melting and -annealing activities in a dose-dependent manner; a relatively low amount of p50 promotes formation of RNA duplexes, whereas an excess of p50 causes unwinding of double-stranded forms. Our results suggest that the alteration of nucleic acid conformation is a basic mechanism of the p50-dependent regulation of gene expression.

Vector design for optimal protein expression

Many DNA constructs are generated for protein expression studies. Translational properties and mRNA stability are crucial aspects that have to be accounted for during DNA construction. An optimized vector for protein overexpression studies is described considering elements in the mature mRNA that influence translatability and stability. Recommendations regarding vector construction for Xenopus laevis embryo injection are provided, based on literature and experimental data. The 5'untranslated region (5'UTR) should be non-regulated, short, unstructured, and without AUG codons. The sequence around the start codon should match the initiation context of the species studied (ACCAUGG, for vertebrates), and the open reading frame should be cloned with its own stop codon, followed by a G or A residue. Furthermore, the 3'UTR should be non-regulated, and a strong polyadenylation signal must be included in DNA vectors. In RNA template vectors, the presence of a poly(A) or AC tail is essential for stability, as well as for translation efficiency in mRNA injection experiments. These aspects result in high-level expression of exactly the desired protein. Easily obtainable examples of the sequences [5'UTR, 3'UTR, and poly(A) signal] are suggested.

Effect of baculovirus infection on the mRNA and protein levels of the Spodoptera frugiperda eukaryotic initiation factor 4E

The cDNA sequence of eukaryotic translation initiation factor eIF4E was derived from a Spodoptera frugiperda cDNA library. Eight tryptophan residues, typical for eIF4E, are strictly conserved in the encoded 210 amino acid protein. A polyclonal antiserum detected a 26 kDa protein in lepidopteran cell lines, but not in dipteran cells. Sf21 cells have a single eIF4E gene copy, which is transcribed into a 1500 nt transcript. Infection with AcMNPV resulted in a decrease in eIF4E mRNA starting between 12 and 24 h postinfection (p.i.), while reduced eIF4E protein levels were observed at 48 h p.i. Two forms of eIF4E were recognized that differed in their iso-electric point, of which the relative abundance did not change during infection. Mutagenesis experiments using recombinant baculoviruses revealed that the variation in mobility between these two forms did not result from a difference in the phosphorylation state of Ser-202, the serine residue that corresponds with the eIF4E phosphorylation site in mammalian eIF4E.

Secretory pathway limits the enhanced expression of classical swine fever virus E2 glycoprotein in insect cells

The 3' untranslated region (UTR) is an important element that determines the level of recombinant protein expression via baculovirus vectors. Previous work using chloramphenicol acetyl transferase as reporter has shown that p10-promoter based baculovirus vectors with the authentic p10 3' UTR resulted in higher expression levels than vectors carrying an SV40 early terminator, as part of a lacZ selection cassette. To examine whether a similar increase in expression levels could be obtained for baculovirus-expressed glycoproteins, the classical swine fever virus E2 antigen was used as a model. With the authentic p10 3' UTR higher levels of E2 transcript were found than in the presence of the SV40 terminator. This higher number of transcripts was accompanied by elevated levels of intracellular, non-glycosylated E2 protein. However, the levels of intracellular glycosylated forms of E2 and of extracellular E2 were similar for both type of terminators. These results show that translation of the recombinant mRNA is not the rate limiting step in the expression of glycoproteins, but the downstream processing and secretion of the translation products.

Sequence and translation initiation properties of the xenopus TGFbeta5, PDGF-A, and PDGF-alpha receptor 5' untranslated regions

The properties of the architecturally complex Xenopus laevis TGFbeta5, PDGF-A and PDGF-alpha receptor 5'UTRs were investigated. 5' extended cDNAs were obtained by 5'RACE, resulting in long 5'UTRs (478-710 nt) with multiple upstream AUGs (3-13), andthe potential to fold into stable structures. Injection studies suggested that the cloned PDGF-alphaR 5'UTR contains an intron. Splicing at potential 5' and 3' splice sites would result in a non-complex 5'UTR of 142 nt. The above mentioned 5'UTR characteristics are inhibitory for ribosomal scanning. Indeed, relative to the beta-globin 5'UTR, the complex 5'UTRs strongly repressed initiation of protein synthesis in pre-MBT Xenopus embryos. However, later in embryogenesis, the inhibition was partly relieved. The results show temporal translational control by these 5'UTRs. Transgenic embryos showed that the 5'UTRs allowed translation throughout the embryo; spatial control could not be observed. Interestingly, a fragment in the PDGF-A 5'UTR highly similar to an element in the human PDGF-A 5'UTR is complementary to Xenopus 18S ribosomal RNA. None of these Xenopus 5'UTRs contains an IRES, as determined by injecting bicistronic constructs.

Controlled translation initiation on insulin-like growth factor 2-leader 1 during Xenopus laevis embryogenesis

A number of growth factors, whose spatio-temporal expression is essential for embryonic development, are encoded by mRNAs with a complex 5'UTR. Human insulin-like growth factor 2 mRNA contains a long (592 nucleotides) 5'UTR (IGFl1) with one upstream open reading frame and stable stem-loop structures, elements which might be important for controlled translation. To investigate whether these unusual features of IGFl1 can control translation initiation during embryogenesis, we examined the initiation efficiency on this 5'UTR during development of Xenopus laevis. The results demonstrate that IGFl1 strongly represses translation of a reporter in early embryos, compared with the Xenopus beta-globin 5'UTR. The inhibition is alleviated soon after the midblastula transition, suggesting a stimulatory effect of the transcription start. However, a similar stimulation of IGFl1-driven translation is seen in embryos in which de novo transcription was inhibited by actinomycin D. Furthermore, it is shown that up-regulation of IGFl1 activity is independent of eIF4E levels, and activity of IGFl1 is observed in all tissues of transgenic Xenopus embryos. These results indicate that post-translational modulation of a trans-acting factor enables efficient initiation on this complex 5'UTR after the midblastula transition.

Cloning and analysis of the untranslated regions of the Xenopus laevis Connexin30 mRNA

The full-length 5' and 3' untranslated regions (UTRs) of Xenopus laevis Connexin30 (Cx30) mRNA were cloned and sequenced. The Cx30 messenger contains a 148 nt 5' UTR and a 480 nt 3' UTR. Four different constructs were made to enable the analysis of the role of the Cx30 UTRs in translation efficiency and in protein localization in the early Xenopus embryo. Transcripts encoded the Green Fluorescent Protein (GFP) reporter and contained the 5' and 3' UTR of either Cx30 or globin. In vivo analyses after injection of the transcripts into one cell-stage Xenopus embryos showed that the Cx30 3' UTR enables very efficient translation. The 5' UTR was slightly inhibitory compared with the globin 5' UTR. The localization of the produced GFP was analyzed. GFP was ubiquitously expressed in all parts of the embryo. Based on this observation we conclude that neither the 5' UTR nor the 3' UTR confers specific localization of the translation of the Cx30 mRNA in the embryo.

Translational control of the Xenopus laevis connexin-41 5'-untranslated region by three upstream open reading frames

The Xenopus laevis Connexin-41 (Cx41) mRNA contains three upstream open reading frames (uORFs) in the 5'-untranslated region (UTR). We analyzed the translation efficiency of constructs containing the Cx41 5'-UTR linked to the green fluorescent protein reporter after injection of transcripts into one-cell stage Xenopus embryos. The translational efficiency of the wild-type Cx41 5'-UTR was only 2% compared with that of the beta-globin 5'-UTR. Mutation of each of the three uAUGs into AAG codons enhanced translation 82-, 9-, and 4-fold compared with the wild-type Cx41 5'-UTR. Based on these increased translation efficiencies, the percentages of ribosomes that recognized the uAUGs were calculated. Only 0.03% of the ribosomes that entered at the cap structure scanned the entire 5'-UTR and translated the main ORF. The results indicate that all uAUGs are recognized by the majority of the scanning ribosomes and that the three uAUGs strongly modulate translation efficiency in Xenopus laevis embryos. Based on these data, a model of ribosomal flow along the mRNA is postulated. We conclude that the three uORFs may play an important role in the regulation of Cx41 expression.

Identification of caspase 3-mediated cleavage and functional alteration of eukaryotic initiation factor 2alpha in apoptosis

Induction of apoptosis in a variety of cell types leads to inhibition of protein synthesis. Recently, the cleavage of eukaryotic translation initiation factor 4G (eIF4G) by caspase 3 was described as a possible event contributing to translation inhibition. Here, we report the cleavage of another initiation factor in apoptotic cells, eIF2alpha, that could contribute to regulation of translation during apoptosis. This cleavage event could be completely inhibited by pretreatment of HeLa cells with Z-VAD-fmk. In vitro analysis using purified eIF2 and purified caspases showed cleavage of eIF2alpha by caspase 3, 6, 8, and 10 but not 9. Caspase 3 most efficiently cleaved eIF2alpha and this could be inhibited by addition of Ac-DEVD-CHO in vitro. Comparison of cleavage of phosphorylated versus nonphosphorylated eIF2alpha revealed a modest preference of the caspases for the nonphosphorylated form. When eIF2. 2B complex was used as substrate, only caspase 3 was capable of eIF2alpha cleavage, which was not affected by phosphorylation of the alpha subunit. The eIF2.GDP binary complex was cleaved much less efficiently by caspase 3. Sequence analysis of the cleavage fragment suggested that the cleavage site is located in the C-terminal portion of the protein. Analysis showed that after caspase cleavage, exchange of GDP bound to eIF2 was very rapid and no longer dependent upon eIF2B. Furthermore, in vitro translation experiments indicated that cleavage of eIF2alpha results in functional alteration of the eIF2 complex, which no longer stimulated upstream AUG selection on a mRNA containing a viral internal ribosome entry site and was no longer capable of stimulating overall translation. In conclusion, we describe here the cleavage of a translation initiation factor, eIF2alpha that could contribute to inhibition or alteration of protein synthesis during the late stages of apoptosis.

Cloning and analysis of cDNAs encoding the hypusine-containing protein eIF5A of two lepidopteran insect species

Eukaryotic initiation factor eIF5A is essential for cell viability and contains a characteristic post-translational modification of a specific lysine residue into a hypusine. cDNAs with similarity to eIF5A sequences were derived from Spodoptera exigua and S. frugiperda cDNA libraries. The deduced amino acid sequences are identical for both species and predict a protein with a molecular mass of 17.5 kDa. The Drosophila melanogaster eIF5A cDNA sequence was retrieved from the Drosophila EST Project. The predicted protein is 80% similar to Spodoptera eIF5A. A single eIF5A gene copy is present in the S. frugiperda genome, which is transcribed into four different transcripts. Infection of S. frugiperda cells with a baculovirus resulted in a strong decline of all four transcripts already at 12 h after infection. In contrast, the eIF5A protein was fairly stable up to 48 h post infection.