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1.
Oncologist ; 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837109

ABSTRACT

Glioblastoma, the most common malignant brain tumor in adults, is associated with a median overall survival duration of less than 2 years. Extraneural metastases occur in less than 1% of all patients with glioblastoma. The mechanism of extraneural metastasis is unclear. We present a case of extensive extraneural, extraosseous, epidural, and soft-tissue metastasis of glioblastoma. The diagnosis of metastatic glioblastoma was made only after next-generation sequencing (NGS) of the metastatic paraspinal lesions was completed. The CDK4, pTERT, PTEN, and TP53 molecular alterations seen in the initial intracranial glioblastoma were found in the paraspinal tumor, along with the addition of MYC, which is implicated in angiogenesis and epidermal-to-mesenchymal transition. Immunohistochemical stains showed that neoplastic cells were negative for GFAP. In conclusion, this case raises awareness about the role of NGS in the diagnosis of extraneural glioblastoma. This diagnosis was not possible with histology alone and only became evident after molecular profiling of the metastatic lesions and its comparison to the original tumor.

2.
Oncologist ; 2024 May 30.
Article in English | MEDLINE | ID: mdl-38815166

ABSTRACT

The prognosis of patients with glioblastoma (GBM) remains poor despite current treatments. Targeted therapy in GBM has been the subject of intense investigation but has not been successful in clinical trials. The reasons for the failure of targeted therapy in GBM are multifold and include a lack of patient selection in trials, the failure to identify driver mutations, and poor blood-brain barrier penetration of investigational drugs. Here, we describe a case of a durable complete response in a newly diagnosed patient with GBM with leptomeningeal dissemination and PTPRZ1-MET fusion who was treated with tepotinib, a brain-penetrant MET inhibitor. This case of successful targeted therapy in a patient with GBM demonstrates that early molecular testing, identification of driver molecular alterations, and treatment with brain-penetrant small molecule inhibitors have the potential to change the outcome in select patients with GBM.

3.
Acta Neuropathol ; 147(1): 85, 2024 05 17.
Article in English | MEDLINE | ID: mdl-38758238

ABSTRACT

Pituitary neuroendocrine tumors (PitNETs) exhibiting aggressive, treatment-refractory behavior are the rare subset that progress after surgery, conventional medical therapies, and an initial course of radiation and are characterized by unrelenting growth and/or metastatic dissemination. Two groups of patients with PitNETs were sequenced: a prospective group of patients (n = 66) who consented to sequencing prior to surgery and a retrospective group (n = 26) comprised of aggressive/higher risk PitNETs. A higher mutational burden and fraction of loss of heterozygosity (LOH) was found in the aggressive, treatment-refractory PitNETs compared to the benign tumors (p = 1.3 × 10-10 and p = 8.5 × 10-9, respectively). Within the corticotroph lineage, a characteristic pattern of recurrent chromosomal LOH in 12 specific chromosomes was associated with treatment-refractoriness (occurring in 11 of 14 treatment-refractory versus 1 of 14 benign corticotroph PitNETs, p = 1.7 × 10-4). Across the cohort, a higher fraction of LOH was identified in tumors with TP53 mutations (p = 3.3 × 10-8). A machine learning approach identified loss of heterozygosity as the most predictive variable for aggressive, treatment-refractory behavior, outperforming the most common gene-level alteration, TP53, with an accuracy of 0.88 (95% CI: 0.70-0.96). Aggressive, treatment-refractory PitNETs are characterized by significant aneuploidy due to widespread chromosomal LOH, most prominently in the corticotroph tumors. This LOH predicts treatment-refractoriness with high accuracy and represents a novel biomarker for this poorly defined PitNET category.


Subject(s)
Loss of Heterozygosity , Neuroendocrine Tumors , Pituitary Neoplasms , Humans , Loss of Heterozygosity/genetics , Pituitary Neoplasms/genetics , Pituitary Neoplasms/pathology , Neuroendocrine Tumors/genetics , Neuroendocrine Tumors/pathology , Neuroendocrine Tumors/therapy , Male , Female , Middle Aged , Adult , Aged , Retrospective Studies , Mutation/genetics , Prospective Studies
4.
J Neurooncol ; 167(1): 181-188, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38372903

ABSTRACT

PURPOSE: Bevacizumab has evolved as an integral treatment option for patients with high-grade gliomas. Little is known about clinical risk factors that predispose patients with high-grade gliomas receiving bevacizumab to VTE or ICH. We sought to characterize the clinical risk factors associated with risk of either event. METHODS: In this multi-institutional retrospective study, we first evaluated patients with high-grade gliomas who were treated with bevacizumab at University of Texas MD Anderson Cancer Center from 2015-2021. We compared clinical and treatment-related factors among three cohorts: those who developed VTE, ICH, or neither. We further compared survival outcomes of these patients from the time of bevacizumab initiation. Then to further confirm our results in a non-cancer center hospital setting we evaluated patients from two Ascension Seton Hospitals in Austin, Texas which are affiliated with Dell Medical School at the University of Texas at Austin from 2017-2022. RESULTS: We found that the presence of cerebral macrobleeding, defined as a magnetic susceptibility of > 1 cm3 on magnetic resonance imaging, was highly associated with risk of developing ICH after initiation of bevacizumab. Development of ICH was significantly associated with poorer survival outcomes. We did not find a statistically significant effect of VTE on survival after bevacizumab initiation. CONCLUSION: In order to stratify the risk for developing ICH before the initiation of bevacizumab, we recommend to assess for the presence of cerebral macrobleeding as it is associated with ICH development.


Subject(s)
Brain Neoplasms , Glioma , Venous Thromboembolism , Humans , Bevacizumab/adverse effects , Venous Thromboembolism/chemically induced , Retrospective Studies , Glioma/complications , Glioma/drug therapy , Risk Factors , Brain Neoplasms/pathology
5.
Mol Cell ; 61(2): 187-98, 2016 Jan 21.
Article in English | MEDLINE | ID: mdl-26774281

ABSTRACT

While cellular GTP concentration dramatically changes in response to an organism's cellular status, whether it serves as a metabolic cue for biological signaling remains elusive due to the lack of molecular identification of GTP sensors. Here we report that PI5P4Kß, a phosphoinositide kinase that regulates PI(5)P levels, detects GTP concentration and converts them into lipid second messenger signaling. Biochemical analyses show that PI5P4Kß preferentially utilizes GTP, rather than ATP, for PI(5)P phosphorylation, and its activity reflects changes in direct proportion to the physiological GTP concentration. Structural and biological analyses reveal that the GTP-sensing activity of PI5P4Kß is critical for metabolic adaptation and tumorigenesis. These results demonstrate that PI5P4Kß is the missing GTP sensor and that GTP concentration functions as a metabolic cue via PI5P4Kß. The critical role of the GTP-sensing activity of PI5P4Kß in cancer signifies this lipid kinase as a cancer therapeutic target.


Subject(s)
Carcinogenesis/metabolism , Carcinogenesis/pathology , Guanosine Triphosphate/metabolism , Intracellular Space/enzymology , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Animals , Cell Proliferation , Crystallography, X-Ray , HEK293 Cells , Humans , Hydrolysis , Kinetics , Mice , Molecular Sequence Data , Mutant Proteins/chemistry , Mutant Proteins/metabolism , Phosphatidylinositol Phosphates/metabolism , Protein Binding , Proteomics , Signal Transduction
6.
Cancer ; 129(18): 2848-2855, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37227811

ABSTRACT

BACKGROUND: Collaborative relationships between academic oncology and industry (pharmaceutical, biotechnology, "omic," and medical device companies) are essential for therapeutic development in oncology; however, limited research on engagement in and perceptions of these relationships has been done. METHODS: Survey questions were developed to evaluate relationships between academic oncology and industry. An electronic survey was delivered to 1000 randomly selected members of the American Society of Clinical Oncology, a professional organization for oncologists, eliciting respondents' views around oncology-industry collaborations. The responses were analyzed according to prespecified plans. RESULTS: There were 225 survey respondents. Most were from the United States (70.0%), worked at an academic institution (60.1%), worked in medical oncology (81.2%), and had an active relationship with industry (85.8%). One quarter (26.7%) of respondents reported difficulty establishing a relationship with industry collaborators, and most respondents (75%) did not report having had mentorship in developing these relationships. The majority (85.3%) of respondents considered these collaborations important to their careers. Respondents generally thought that scientific integrity was preserved (92%), and most respondents (95%) had little concern over the quality of the collaborative product. Many (60%) shared concerns over potential conflict of interest if an individual with a compensated relationship promoted an industry product for clinical care/research, yet most respondents (67%) stated these relationships did not shape their interactions with patients. CONCLUSIONS: This study provides novel data characterizing the nature of collaborative relationships between clinicians, researchers, and industry in oncology. Although respondents considered these collaborations an important part of clinical and academic oncology, formal education or mentorship around these relationships was rare. Conflicting findings around conflict of interest highlight the importance of more dedicated research in this area. PLAIN LANGUAGE SUMMARY: Business enterprises in health care play a central role in cancer research and care, driving the development of new medical testing, drugs, and devices. Effective working relationships among clinicians, researchers, and these industry partners can promote innovative research and enhance patient care. Study of these collaborations has been limited to date. Through distribution of a questionnaire to cancer clinicians and researchers, we found that most participants consider these relationships valuable, though they find establishing such relationships challenging partly because of gaps in educational programs in this area. Our findings also highlight the need for further policy around the potential bias these relationships can introduce.


Subject(s)
Neoplasms , Oncologists , Humans , United States , Conflict of Interest , Medical Oncology , Neoplasms/therapy , Commerce , Drug Industry
7.
Cancer ; 127(13): 2368-2375, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33721338

ABSTRACT

BACKGROUND: The authors analyzed the incidence and types of second malignant neoplasms (SMNs) in patients treated for medulloblastoma. METHODS: The authors compared the incidence of SMNs after radiotherapy (RT) for medulloblastoma in patients treated in 1973-2014 with the incidence in the general population with the multiple primary-standardized incidence ratio function of Surveillance, Epidemiology, and End Results 9. Observed-to-expected incidence (O/E) ratios and 95% confidence intervals (CIs) were reported for the entire cohort and by disease site according to age at diagnosis, treatment era, and receipt of chemotherapy. P values < .05 were considered statistically significant. RESULTS: Of the 1294 patients with medulloblastoma who received RT, 68 developed 75 SMNs. The O/E ratio for SMNs among all patients was 4.49 (95% CI, 3.53-5.62; P < .05). The site at highest risk was the central nervous system (CNS; O/E, 40.62; 95% CI, 25.46-61.51), which was followed by the endocrine system (O/E, 15.95; 95% CI, 9.12-25.91), bone (O/E, 14.45; 95% CI, 1.75-52.21), soft tissues (O/E, 9.01; 95% CI, 1.09-32.56), the digestive system (O/E, 5.03; 95% CI, 2.51-9.00), and the lymphatic/hematopoietic system (O/E, 3.37; 95% CI, 1.35-6.94). The O/E ratio was higher for patients given chemotherapy and RT (O/E, 5.52; 95% CI, 3.75-7.83) than for those given RT only (O/E, 3.96; 95% CI, 2.88-5.32). CONCLUSIONS: Patients with medulloblastoma are at elevated risk for SMNs in comparison with the general population. Variations in O/E for SMNs by organ systems were found for treatment modality, age at diagnosis, and time of diagnosis. The most common site, the CNS, was involved more often in younger patients and those given chemotherapy with RT.


Subject(s)
Cerebellar Neoplasms , Medulloblastoma , Neoplasms, Second Primary , Cerebellar Neoplasms/complications , Cerebellar Neoplasms/epidemiology , Cerebellar Neoplasms/radiotherapy , Humans , Incidence , Medulloblastoma/complications , Medulloblastoma/epidemiology , Medulloblastoma/radiotherapy , Neoplasms, Second Primary/epidemiology , Neoplasms, Second Primary/etiology , Neoplasms, Second Primary/pathology , Risk Factors
8.
Adv Exp Med Biol ; 1342: 233-258, 2021.
Article in English | MEDLINE | ID: mdl-34972967

ABSTRACT

Immunotherapy has changed the landscape of treatment of many solid and hematological malignancies and is at the forefront of cancer breakthroughs. Several circumstances unique to the central nervous system (CNS) such as limited space for an inflammatory response, difficulties with repeated sampling, corticosteroid use for management of cerebral edema, and immunosuppressive mechanisms within the tumor and brain parenchyma have posed challenges in clinical development of immunotherapy for intracranial tumors. Nonetheless, the success of immunotherapy in brain metastases (BMs) from solid cancers such as melanoma and non-small cell lung cancer (NSCLC) proves that the CNS is not an immune-privileged organ and is capable of initiating and regulating immune responses that lead to tumor control. However, the development of immunotherapeutics for the most malignant primary brain tumor, glioblastoma (GBM), has been challenging due to systemic and profound tumor-mediated immunosuppression unique to GBM, intratumoral and intertumoral heterogeneity, and lack of stably expressed clonal antigens. Here, we review recent advances in the field of immunotherapy for neuro-oncology with a focus on BM, GBM, and rare CNS cancers.


Subject(s)
Brain Neoplasms , Carcinoma, Non-Small-Cell Lung , Glioblastoma , Lung Neoplasms , Brain Neoplasms/therapy , Humans , Immunotherapy
9.
Adv Exp Med Biol ; 1342: 417-429, 2021.
Article in English | MEDLINE | ID: mdl-34972978

ABSTRACT

Immunotherapy has revolutionized treatment of cancer over the past two decades. The antitumor effects of immunotherapy approaches are at the expense of growing spectrum of immune-related adverse events (irAEs) due to cross-reactivity between the tumor and normal host tissue. These adverse events can happen in any organ and range from mild to severe and even life-threatening conditions. While neurological irAEs associated with immune checkpoint inhibitors (CPIs) are rare, they pose a significant challenge in management as the clinical phenotypes are heterogenous and frequently necessitate cessation of therapy and systemic immune suppression and lead to transient functional decline. On the other hand, immune effector cell-associated neurotoxicity (ICANS) is common, frequently occurs in conjunction with cytokine release syndrome (CRS), and poses a significant clinical challenge to the development and widespread use of these effective therapies. Early recognition of these neurological syndromes, timely diagnosis, and thoughtful management are key for further clinical development of these effective therapies in cancer patients. Here, we describe clinical phenotypes of CPI-induced neurological complications and ICANS and discuss steps in clinical monitoring, diagnosis, and effective management.


Subject(s)
Neoplasms , Neurotoxicity Syndromes , Humans , Immunologic Factors , Immunotherapy/adverse effects , Neoplasms/drug therapy , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/therapy
10.
Pediatr Blood Cancer ; 67(8): e28373, 2020 08.
Article in English | MEDLINE | ID: mdl-32453481

ABSTRACT

BACKGROUND: As treatment modalities for medulloblastoma have developed and overall survival (OS) has improved, there are relatively limited data on the impact of long-term effects such as risk of second primary tumors (SPT). To address the knowledge gap, we analyzed factors associated with the risk of SPT and OS by treatment modality for medulloblastoma. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER)-18 database for patients diagnosed with medulloblastoma in 1973-2014. Patients were then grouped by age, gender, race, geographic region, histology, adjuvant treatment (no radiation [RT] and no chemotherapy [CT], RT and CT, RT alone, or CT alone), era of diagnosis (1973-1994 or 1995-2014), and survival time. Cumulative incidence, factors associated with SPT and OS were analyzed. RESULTS: Of 2271 patients, 146 developed SPT, of which 42 were benign. The incidence of SPT was 3.1% and 4.9% at 10 and 15 years, respectively. The incidence of SPT was 3.1% with RT + CT versus 3.7% with RT alone at 10 years. The most common site for an SPT was the central nervous system. Female gender (P = 0.01) and longer OS of ≥21 years (P < 0.01) were associated with higher risk of SPT. RT + CT led to better OS than RT only (66.1% and 61.4% vs 55.6% and 49.7% at 10 and 15 years) (P < 0.01). CONCLUSIONS: Medulloblastoma patients have a relatively low risk of SPT at 10 years with treatment. Use of RT + CT led to better OS with no statistical difference in SPT compared with the RT alone.


Subject(s)
Cerebellar Neoplasms , Databases, Factual , Medulloblastoma , Neoplasms, Second Primary , Adolescent , Adult , Cerebellar Neoplasms/diagnosis , Cerebellar Neoplasms/mortality , Cerebellar Neoplasms/therapy , Child , Child, Preschool , Disease-Free Survival , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Medulloblastoma/diagnosis , Medulloblastoma/mortality , Medulloblastoma/therapy , Neoplasms, Second Primary/diagnosis , Neoplasms, Second Primary/mortality , Retrospective Studies , Risk Factors , Survival Rate
11.
Adv Exp Med Biol ; 1244: 183-203, 2020.
Article in English | MEDLINE | ID: mdl-32301015

ABSTRACT

Immunotherapy has changed the landscape of treatment of many solid and hematological malignancies and is at the forefront of cancer breakthroughs. Several circumstances unique to the central nervous system (CNS) such as limited space for an inflammatory response, difficulties with repeated sampling, corticosteroid use for management of cerebral edema, and immunosuppressive mechanisms within the tumor and brain parenchyma have posed challenges in clinical development of immunotherapy for intracranial tumors. Nonetheless, the success of immunotherapy in brain metastases (BMs) from solid cancers such as melanoma and non-small cell lung cancer (NSCLC) proves that the CNS is not an immune-privileged organ and is capable of initiating and regulating immune responses that lead to tumor control. However, the development of immunotherapeutics for the most malignant primary brain tumor, glioblastoma (GBM), has been challenging due to systemic and profound tumor-mediated immunosuppression unique to GBM, intratumoral and intertumoral heterogeneity, low mutation burden, and lack of stably expressed clonal antigens. Here, we review recent advances in the field of immunotherapy for neuro-oncology with a focus on BM and GBM.


Subject(s)
Brain Neoplasms/therapy , Glioblastoma/therapy , Immunotherapy , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Carcinoma, Non-Small-Cell Lung/pathology , Glioblastoma/pathology , Humans , Melanoma/pathology
12.
Int J Mol Sci ; 22(1)2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33396284

ABSTRACT

Glioblastoma is the most common malignant primary brain tumor in adults and is almost invariably fatal. Despite our growing understanding of the various mechanisms underlying treatment failure, the standard-of-care therapy has not changed over the last two decades, signifying a great unmet need. The challenges of treating glioblastoma are many and include inadequate drug or agent delivery across the blood-brain barrier, abundant intra- and intertumoral heterogeneity, redundant signaling pathways, and an immunosuppressive microenvironment. Here, we review the innate and adaptive molecular mechanisms underlying glioblastoma's treatment resistance, emphasizing the intrinsic challenges therapeutic interventions must overcome-namely, the blood-brain barrier, tumoral heterogeneity, and microenvironment-and the mechanisms of resistance to conventional treatments, targeted therapy, and immunotherapy.


Subject(s)
Antineoplastic Agents/therapeutic use , Brain Neoplasms/drug therapy , Drug Resistance, Neoplasm , Glioblastoma/drug therapy , Molecular Targeted Therapy , Tumor Microenvironment/drug effects , Animals , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Glioblastoma/metabolism , Glioblastoma/pathology , Humans
13.
Int J Mol Sci ; 21(6)2020 Mar 13.
Article in English | MEDLINE | ID: mdl-32182988

ABSTRACT

Recent efforts in brain tumor research have been directed towards the modulation of the immune system for therapeutic interventions. Several human cancers, including gliomas, are infiltrated with immune cell types-including neutrophils and myeloid-derived suppressor cells-that contribute to tumor progression, invasiveness, and treatment resistance. The role of tumor-associated neutrophils and myeloid-derived suppressor cells in cancer biology remains elusive, as these cells can exert a multitude of pro-tumor and antitumor effects. In this review, we provide the current understanding and novel insights on the role of neutrophils and myeloid-derived suppressor cells in glioma progression and treatment resistance, as well as the mechanisms of pleiotropic behaviors in these cells during disease progression, with an emphasis on possible strategies to reprogram these cells towards their antitumor actions.


Subject(s)
Brain Neoplasms/immunology , Drug Resistance, Neoplasm , Glioma/immunology , Myeloid-Derived Suppressor Cells/immunology , Neutrophils/immunology , Animals , Brain Neoplasms/drug therapy , Brain Neoplasms/radiotherapy , Glioma/drug therapy , Glioma/radiotherapy , Humans , Radiation Tolerance
14.
Curr Opin Neurol ; 32(6): 864-871, 2019 12.
Article in English | MEDLINE | ID: mdl-31567548

ABSTRACT

PURPOSE OF REVIEW: Checkpoint inhibitors (CPIs) represent the forefront of novel immunotherapeutic approaches for the treatment of solid cancers. However, the clinical development of CPIs in glioblastoma (GBM) has been challenging owing to an immunosuppressive tumor microenvironment and, possibly, low tumor mutation burden. Here, we review possible mechanisms responsible for the success of programmed cell death-1 (PD-1) blockade in patients with hypermutated GBM, recent clinical trials of anti-PD-1 monotherapy, trials incorporating neoadjuvant strategies, and trials of immunotherapy combination approaches in GBM. Mechanisms of resistance to immunotherapy and methods to overcome these challenges are also discussed. RECENT FINDINGS: Although two large phase III trials failed to demonstrate the superior efficacy of CPI in comparison with the standard of care in newly diagnosed and recurrent GBM, recent studies suggest that opportunities exist in some patients with GBM. A phase II study showed longer survival in patients with recurrent GBM who received neoadjuvant anti-PD-1 therapy than in those who received it as adjuvant therapy. In addition, cases of response to anti-PD-1 therapy in GBM patients with clonal hypermutator tumors have been reported. SUMMARY: Even though anti-PD-1 therapy does not seem to provide a benefit for molecularly unselected GBM patients, the success of PD-1 blockade in certain subsets of patients is encouraging.


Subject(s)
Brain Neoplasms/drug therapy , Glioma/drug therapy , Immunologic Factors/therapeutic use , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Animals , Humans
15.
Curr Treat Options Oncol ; 20(8): 64, 2019 06 24.
Article in English | MEDLINE | ID: mdl-31236711

ABSTRACT

OPINION STATEMENT: Medulloblastoma (MB) is a malignant embryonal tumor of the posterior fossa and is the most common type of brain cancer in pediatric patients. In contrast, adult MB is very rare with an incidence of 0.6 per million per year and mostly affects young adults below the age of 40. Recent molecular analyses of pediatric and adult MB have classified these tumors into at least four individual molecular subgroups (SHH, WNT, group 3, and group 4) with distinct demographics, histology, and prognosis. The discrete biological composition of these tumors likely explains the marked heterogeneity in responses seen to conventional therapies such as radiation and cytotoxic chemotherapies. Given the low incidence of adult MB, prospective studies are challenging and scarce, and management guidelines are largely derived from the pediatric MB patient population and retrospective data. However, adult MB is clinically and molecularly distinct from pediatric MB and a comprehensive review of published literature on adult MB highlighting their differences is warranted. Here, we review the management of adult MB focusing on recent studies exploring the effectiveness of upfront chemotherapy, clinical trials in the context of molecular subgroup-specific therapies, and the potential role of immunotherapy in treating this disease.


Subject(s)
Cerebellar Neoplasms/diagnosis , Cerebellar Neoplasms/therapy , Medulloblastoma/diagnosis , Medulloblastoma/therapy , Cerebellar Neoplasms/etiology , Cerebellar Neoplasms/mortality , Clinical Trials as Topic , Combined Modality Therapy , Diagnostic Imaging , Disease Management , Humans , Medulloblastoma/etiology , Medulloblastoma/mortality , Neoplasm Grading , Neoplasm Metastasis , Neoplasm Staging , Treatment Outcome
16.
J Biol Chem ; 289(7): 3950-9, 2014 Feb 14.
Article in English | MEDLINE | ID: mdl-24338482

ABSTRACT

Mammalian cells encode three closely related Ras proteins, H-Ras, N-Ras, and K-Ras. Oncogenic K-Ras mutations frequently occur in human cancers, which lead to dysregulated cell proliferation and genomic instability. However, mechanistic role of the Ras isoform regulation have remained largely unknown. Furthermore, the dynamics and function of negative regulation of GTP-loaded K-Ras have not been fully investigated. Here, we demonstrate RasG, the Dictyostelium orthologue of K-Ras, is targeted for degradation by polyubiquitination. Both ubiquitination and degradation of RasG were strictly associated with RasG activity. High resolution tandem mass spectrometry (LC-MS/MS) analysis indicated that RasG ubiquitination occurs at C-terminal lysines equivalent to lysines found in human K-Ras but not in H-Ras and N-Ras homologues. Substitution of these lysine residues with arginines (4KR-RasG) diminished RasG ubiquitination and increased RasG protein stability. Cells expressing 4KR-RasG failed to undergo proper cytokinesis and resulted in multinucleated cells. Ectopically expressed human K-Ras undergoes polyubiquitin-mediated degradation in Dictyostelium, whereas human H-Ras and a Dictyostelium H-Ras homologue (RasC) are refractory to ubiquitination. Our results indicate the existence of GTP-loaded K-Ras orthologue-specific degradation system in Dictyostelium, and further identification of the responsible E3-ligase may provide a novel therapeutic approach against K-Ras-mutated cancers.


Subject(s)
Cytokinesis/physiology , Dictyostelium/enzymology , Proteolysis , Proto-Oncogene Proteins/metabolism , Protozoan Proteins/metabolism , Ubiquitination/physiology , ras Proteins/metabolism , Dictyostelium/genetics , Guanosine Triphosphate/genetics , Guanosine Triphosphate/metabolism , Humans , Lysine/genetics , Lysine/metabolism , Protein Stability , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , Protozoan Proteins/genetics , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , ras Proteins/genetics
17.
JCO Precis Oncol ; 8: e2300442, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38394467

ABSTRACT

PURPOSE: The purpose of this article was to provide an overview of syndromic gliomas. DESIGN: The authors conducted a nonsystematic literature review. RESULTS: Cancer predisposition syndromes (CPSs) are genetic conditions that increase one's risk for certain types of cancer compared with the general population. Syndromes that can predispose one to developing gliomas include neurofibromatosis, Li-Fraumeni syndrome, Lynch syndrome, and tuberous sclerosis complex. The standard treatment for sporadic glioma may involve resection, radiation therapy, and/or alkylating chemotherapy. However, DNA-damaging approaches, such as radiation and alkylating agents, may increase the risk of secondary malignancies and other complications in patients with CPSs. In some cases, depending on genetic aberrations, targeted therapies or immunotherapeutic approaches may be considered. Data on clinical characteristics, therapeutic strategies, and prognosis of syndromic gliomas remain limited. CONCLUSION: In this review, we provide an overview of syndromic gliomas with a focus on management for patients with CPSs and the role of novel treatments that can be considered.


Subject(s)
Glioma , Li-Fraumeni Syndrome , Humans , Glioma/genetics , Glioma/therapy , Li-Fraumeni Syndrome/complications , Li-Fraumeni Syndrome/diagnosis , Li-Fraumeni Syndrome/genetics , Prognosis , Genotype
18.
J Gastrointest Oncol ; 15(3): 1331-1340, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38989402

ABSTRACT

Background: Leptomeningeal metastases (LM) in gastroesophageal (GE) malignancies are exceedingly rare. Historically, treatment for LM has included steroids, radiation, chemotherapy, and intrathecal (IT) chemotherapy. However, the outcomes in GE malignancies with LM remain poor. Unfortunately, clinical trials in GE malignancies have traditionally excluded those with LM, limiting advances in therapeutic strategies. Given that LM poses potentially devastating neurologic and psychologic sequelae, there is an urgent need for more effective treatments. Case Description: Patient 1 is a 44-year-old woman with localized esophageal adenocarcinoma who undergoes neoadjuvant chemoradiation followed by esophagectomy. Seven months following surgery, she develops ataxia, weakness, and nausea/vomiting. Magnetic resonance imaging (MRI) reveals intracranial disease that is subsequently successfully resected and then treated with gamma knife (GK) radiation. Pathology confirms metastases. Three months later she is found to have LM. She receives palliative whole brain radiation therapy as well as focal radiation to the spine. Following this she transitioned to concurrent IT topotecan plus intravenous (IV) ipilumumab/nivolumab with durable response beyond 14 months. Patient 2 is a 71-year-old man with de novo metastatic esophageal adenocarcinoma with durable response to 5-fluorouracil plus irinotecan. Asymptomatic intracranial metastases are detected on surveillance scans 2 years after initial diagnosis for which he receives GK. Follow up MRI identifies new LM. As such, to treat the LM, he was transitioned to IT topotecan and IV pembrolizumab with good response for 6 months until death from a gastrointestinal bleed. Conclusions: We present two cases of LM in patients with GE adenocarcinoma who had longer survival than what has been reported. They were treated with combination IT topotecan and IV checkpoint inhibition. Further studies evaluating the central nervous system tumor immune-microenvironment can help expand our understanding of how this combination has worked well in our patients and how to care for others with similar scenarios.

19.
Neurooncol Pract ; 11(4): 475-483, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39006516

ABSTRACT

Background: We observed rapid tumor progression following COVID-19 infection among patients with glioblastoma and sought to systematically characterize their disease course in a retrospective case-control study. Methods: Using an institutional database, we retrospectively identified a series of COVID-19-positive glioblastoma cases and matched them by age and sex 1:2 to glioblastoma controls who had a negative COVID-19 test during their disease course. Demographic and clinical data were analyzed. Hyperprogression was defined using modified response evaluation criteria in solid tumors criteria. Time to progression and overall survival were estimated using the Kaplan-Meier method. Results: Thirty-two glioblastoma cases with positive COVID-19 testing were matched to 64 glioblastoma controls with negative testing; age, sex, and molecular profiles did not differ between groups. Progression events occurred in 27 cases (84%) and 46 controls (72%). Of these, 14 cases (52%) presented with multifocal disease or leptomeningeal disease at progression compared with 10 controls (22%; P = .0082). Hyperprogression was identified in 13 cases (48%) but only 4 controls (9%; P = .0001). Cases had disease progression at a median of 35 days following COVID-19 testing, compared with 164 days for controls (P = .0001). Median survival from COVID-19 testing until death was 8.3 months for cases but 17 months for controls (P = .0016). Median overall survival from glioblastoma diagnosis was 20.7 months for cases and 24.6 months for controls (P = .672). Conclusions: Patients with glioblastoma may have accelerated disease progression in the first 2 months after COVID-19 infection. Infected patients should be monitored vigilantly. Future investigations should explore tumor-immune microenvironment changes linking tumor progression and COVID-19.

20.
Cancers (Basel) ; 16(11)2024 May 25.
Article in English | MEDLINE | ID: mdl-38893133

ABSTRACT

(1) Background: Myxopapillary ependymoma (MPE) is a rare tumor of the spine, typically slow-growing and low-grade. Optimal management strategies remain unclear due to limited evidence given the low incidence of the disease. (2) Methods: We analyzed data from 1197 patients with spinal MPE from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2020). Patient demographics, treatment modalities, and survival outcomes were examined using statistical analyses. (3) Results: Most patients were White (89.9%) with a median age at diagnosis of 42 years. Surgical resection was performed in 95% of cases. The estimated 10-year overall survival was 91.4%. Younger age (hazard ratio (HR) = 1.09, p < 0.001) and receipt of surgery (HR = 0.43, p = 0.007) were associated with improved survival. Surprisingly, male sex was associated with worse survival (HR = 1.86, p = 0.008) and a younger age at diagnosis compared to females. (4) Conclusions: This study, the largest of its kind, underscores the importance of surgical resection in managing spinal MPE. The unexpected association between male sex and worse survival warrants further investigation into potential sex-specific pathophysiological factors influencing prognosis. Despite limitations, our findings contribute valuable insights for guiding clinical management strategies for spinal MPE.

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