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24 result(s) for "Ene, Chibawanye I"
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Response of treatment-naive brain metastases to stereotactic radiosurgery
With improvements in survival for patients with metastatic cancer, long-term local control of brain metastases has become an increasingly important clinical priority. While consensus guidelines recommend surgery followed by stereotactic radiosurgery (SRS) for lesions >3 cm, smaller lesions (≤3 cm) treated with SRS alone elicit variable responses. To determine factors influencing this variable response to SRS, we analyzed outcomes of brain metastases ≤3 cm diameter in patients with no prior systemic therapy treated with frame-based single-fraction SRS. Following SRS, 259 out of 1733 (15%) treated lesions demonstrated MRI findings concerning for local treatment failure (LTF), of which 202 /1733 (12%) demonstrated LTF and 54/1733 (3%) had an adverse radiation effect. Multivariate analysis demonstrated tumor size (>1.5 cm) and melanoma histology were associated with higher LTF rates. Our results demonstrate that brain metastases ≤3 cm are not uniformly responsive to SRS and suggest that prospective studies to evaluate the effect of SRS alone or in combination with surgery on brain metastases ≤3 cm matched by tumor size and histology are warranted. These studies will help establish multi-disciplinary treatment guidelines that improve local control while minimizing radiation necrosis during treatment of brain metastasis ≤3 cm. Current guidelines recommend stereotactic radiosurgery for brain metastasis measuring less than 3 cm but there is significant variability in outcomes following treatment. This study shows that in treatment naïve brain metastasis less than 3 cm, intrinsic biological differences across multiple histologies may influence response to stereotactic radiosurgery.
Mutations of the DNA repair gene PNKP in a patient with microcephaly, seizures, and developmental delay (MCSZ) presenting with a high-grade brain tumor
Polynucleotide Kinase-Phosphatase (PNKP) is a bifunctional enzyme that possesses both DNA 3′-phosphatase and DNA 5′-kinase activities, which are required for processing termini of single- and double-strand breaks generated by reactive oxygen species (ROS), ionizing radiation and topoisomerase I poisons. Even though PNKP is central to DNA repair, there have been no reports linking PNKP mutations in a Microcephaly, Seizures, and Developmental Delay (MSCZ) patient to cancer. Here, we characterized the biochemical significance of 2 germ-line point mutations in the PNKP gene of a 3-year old male with MSCZ who presented with a high-grade brain tumor (glioblastoma multiforme) within the cerebellum. Functional and biochemical studies demonstrated these PNKP mutations significantly diminished DNA kinase/phosphatase activities, altered its cellular distribution, caused defective repair of DNA single/double stranded breaks, and were associated with a higher propensity for oncogenic transformation. Our findings indicate that specific PNKP mutations may contribute to tumor initiation within susceptible cells in the CNS by limiting DNA damage repair and increasing rates of spontaneous mutations resulting in pediatric glioma associated driver mutations such as ATRX and TP53.
Genetically engineered macrophages persist in solid tumors and locally deliver therapeutic proteins to activate immune responses
BackgroundThough currently approved immunotherapies, including chimeric antigen receptor T cells and checkpoint blockade antibodies, have been successfully used to treat hematological and some solid tumor cancers, many solid tumors remain resistant to these modes of treatment. In solid tumors, the development of effective antitumor immune responses is hampered by restricted immune cell infiltration and an immunosuppressive tumor microenvironment (TME). An immunotherapy that infiltrates and persists in the solid TME, while providing local, stable levels of therapeutic to activate or reinvigorate antitumor immunity could overcome these challenges faced by current immunotherapies.MethodsUsing lentivirus-driven engineering, we programmed human and murine macrophages to express therapeutic payloads, including Interleukin (IL)-12. In vitro coculture studies were used to evaluate the effect of genetically engineered macrophages (GEMs) secreting IL-12 on T cells and on the GEMs themselves. The effects of IL-12 GEMs on gene expression profiles within the TME and tumor burden were evaluated in syngeneic mouse models of glioblastoma and melanoma and in human tumor slices isolated from patients with advanced gastrointestinal malignancies.ResultsHere, we present a cellular immunotherapy platform using lentivirus-driven genetic engineering of human and mouse macrophages to constitutively express proteins, including secreted cytokines and full-length checkpoint antibodies, as well as cytoplasmic and surface proteins that overcomes these barriers. GEMs traffic to, persist in, and express lentiviral payloads in xenograft mouse models of glioblastoma, and express a non-signaling truncated CD19 surface protein for elimination. IL-12-secreting GEMs activated T cells and induced interferon-gamma (IFNγ) in vitro and slowed tumor growth resulting in extended survival in vivo. In a syngeneic glioblastoma model, IFNγ signaling cascades were also observed in mice treated with mouse bone-marrow-derived GEMs secreting murine IL-12. These findings were reproduced in ex vivo tumor slices comprised of intact MEs. In this setting, IL-12 GEMs induced tumor cell death, chemokines and IFNγ-stimulated genes and proteins.ConclusionsOur data demonstrate that GEMs can precisely deliver titratable doses of therapeutic proteins to the TME to improve safety, tissue penetrance, targeted delivery and pharmacokinetics.
Histone Demethylase Jumonji D3 (JMJD3) as a Tumor Suppressor by Regulating p53 Protein Nuclear Stabilization
Histone methylation regulates normal stem cell fate decisions through a coordinated interplay between histone methyltransferases and demethylases at lineage specific genes. Malignant transformation is associated with aberrant accumulation of repressive histone modifications, such as polycomb mediated histone 3 lysine 27 (H3K27me3) resulting in a histone methylation mediated block to differentiation. The relevance, however, of histone demethylases in cancer remains less clear. We report that JMJD3, a H3K27me3 demethylase, is induced during differentiation of glioblastoma stem cells (GSCs), where it promotes a differentiation-like phenotype via chromatin dependent (INK4A/ARF locus activation) and chromatin independent (nuclear p53 protein stabilization) mechanisms. Our findings indicate that deregulation of JMJD3 may contribute to gliomagenesis via inhibition of the p53 pathway resulting in a block to terminal differentiation.
Preoperative Brain Mapping Predicts Language Outcomes After Eloquent Tumor Resection
When operating on gliomas near critical language regions, surgeons risk either leaving residual tumor or inducing permanent postoperative language deficits (PLDs). Despite the advent of intraoperative mapping techniques, subjective judgments frequently determine important surgical decisions. We aim to inform data‐driven surgery by constructing a non‐invasive mapping approach that quantitatively predicts the impact of individual surgical decisions on long‐term language function. This study included 79 consecutive patients undergoing resection of language‐eloquent gliomas. Patients underwent preoperative navigated transcranial magnetic stimulation (TMS) language mapping to identify language‐positive sites (“TMS points”) and their associated white matter tracts (“TMS tracts”) as well as formal language evaluations pre‐and postoperatively. The resection of regions identified by preoperative mapping was correlated with permanent postoperative language deficits (PLDs). Resected tract segments (RTS) were normalized to MNI space for comparison with normative data. The resection of TMS points did not predict PLDs. However, a TMS point subgroup defined by white matter connectivity significantly predicted PLDs (OR = 8.74, p < 0.01) and demonstrated a canonical distribution of cortical language sites at a group level. TMS tracts recapitulated normative patterns of white matter connectivity defined by the Human Connectome Project. Subcortical resection of TMS tracts predicted PLDs independently of cortical resection (OR = 60, p < 0.001). In patients with PLDs, RTS showed significantly stronger co‐localization with normative language‐associated tracts compared to RTS in patients without PLDs (p < 0.05). Resecting patient‐specific co‐localizations between TMS tracts and normative tracts in native space predicted PLDs with an accuracy of 94% (OR = 134, p < 0.001). Prospective application of this data in a patient with glioblastoma precisely predicted the results of intraoperative language mapping with direct subcortical stimulation. Long‐term postoperative language deficits result from resecting patient‐specific white matter segments. We integrate these findings into a personalized tool that uses TMS language mappings, diffusion tractography, and population‐level connectivity to preoperatively predict the long‐term linguistic impact of individual surgical decisions. This study outlines the development of a predictive model based on preoperative brain mapping capable of accurately predicting the long‐term linguistic impact of individual surgical decisions.
An interdisciplinary consensus on the management of brain metastases in patients with renal cell carcinoma
Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients.
Patterns of Failure After Stereotactic Radiosurgery for Recurrent High-Grade Glioma: A Single Institution Experience of 10 Years
Stereotactic radiosurgery (SRS) is a treatment modality that is frequently used as salvage therapy for small nodular recurrent high-grade gliomas (HGG). Due to the infiltrative nature of HGG, it is unclear if this highly focused technique provides a durable local control benefit. To determine how demographic or clinical factors influence the pattern of failure following SRS for recurrent high-grade gliomas. We retrospectively reviewed clinical, radiographic, and follow-up information for 47 consecutive patients receiving SRS for recurrent HGG at our institution between June 2006 and July 2016. All patients initially presented with an HGG (WHO grade III and IV). Following SRS for recurrence, all patients experienced treatment failure, and we evaluated patterns of local, regional, and distant failure in relation to the SRS 50% isodose line. Most patients with recurrent HGG developed \"in-field\" treatment failure following SRS (n = 40; 85%). Higher SRS doses were associated with longer time to failure (hazards ratio = 0.80 per 1 Gy increase; 95% confidence interval 0.67-0.96; P = .016). There was a statistically significant increase in distant versus in-field failure among older patients (P = .035). This effect was independent of bevacizumab use (odds ratio = 0.54, P = 1.0). Based on our experience, the majority of treatment failures after SRS for recurrent HGG were \"in-field.\" Older patients, however, presented with more distant failures. Our results indicate that higher SRS doses delivered to a larger area as fractioned or unfractioned regimen may prolong time to failure, especially in the older population.
The Role of Immune Checkpoint Inhibitors in Leptomeningeal Disease: A Systematic Review
Background/Aim: Leptomeningeal disease (LMD) is a debilitating complication of advanced malignancies. Immune-checkpoint inhibitors (ICIs) may alter disease course. We analyzed the role and toxicity of ICIs in LMD. Materials and Methods: We systematically reviewed the literature reporting on outcome data of patients with LMD treated with ICIs. Results: We included 14 studies encompassing 61 patients. Lung-cancer (44.3%), breast-cancer (27.9%), and melanoma (23.0%) were the most frequent primary tumors. Median duration of ICI-treatment was 7-months (range=0.5-58.0): pembrolizumab (49.2%), nivolumab (32.8%), ipilimumab (18.0%). Radiological responses included complete response (33.3%), partial response (12.5%), stable disease (33.3%), progressive disease (20.8%). Twenty-two patients developed ICI-related adverse-events, mild (100%) and/or severe (15.6%). Median progression-free and overall survival were 5.1 and 6.3 months, and 12-month survival was 32.1%. Survival correlated with ICI agents (p=0.042), but not with primary tumors (p=0.144). Patients receiving concurrent steroids showed worse survival (p=0.040). Conclusion: ICI therapy is well-tolerated in patients with LMD, but concurrent steroids may worsen survival.
11 Study of Polynucleotide Kinase/Phosphatase (PNKP) Mutations Found in a Patient with Microcephaly, Seizures, and Developmental Delay (MCSZ) and Glioblastoma
The enzyme polynucleotide kinase/phosphatase (PNKP) plays a key role in DNA repair by resolving the chemistry at DNA strand breaks. Mutations in PNKP (chromosome 19q13.4) are known to cause MCSZ, a serious neurodevelopmental disorder, but to date there has been no link to cancer initiation or progression. However, a child with MCSZ recently presented at Seattle Children's Hospital with a 3-cm glioblastoma. The child was shown to have two germline mutations in PNKP. To study the effects of the PNKP mutations found in this patient, we generated mutant PNKP cDNAs carrying either the individual mutations or the double mutation using site directed mutagenesis. These cDNAs were incorporated into bacterial and mammalian expression vectors. The bacterially expressed mutant proteins as well as the wild type have been purified and are undergoing testing for PNKP DNA kinase and phosphatase activity. The PNKP cDNAs, fused to GFP, were expressed in Hela and HCT116 human cancer cell lines. High-content analysis and micro-irradiation techniques are being used to determine PNKP localization within the cells and recruitment to damaged DNA. Our preliminary results indicate that the mutations alter the ratio of nuclear to cytoplasmic PNKP compared to the wild-type protein.
Pseudoaneurysm of the Superficial Temporal Artery After Intracranial Pressure Monitoring Device Placement: Case Report of a Rare Complication
Abstract BACKGROUND AND IMPORTANCE Pseudoaneurysms involving the superficial temporal artery (STA), either iatrogenic or caused by direct trauma, are rare. The STA is prone to injury due to its long course throughout the scalp. Injuries can cause cosmetic defects and/or skin breakdown leading to further complications. CLINICAL PRESENTATION We report a case of delayed iatrogenic pseudoaneurysm of the STA after placement of an intracranial pressure monitor in the setting of acute traumatic brain injury. The patient had a delayed development of a pulsatile mass over his right frontal region, with computed tomography angiography concerning for a pseudoaneurysm of the STA. This was managed with surgical resection with complete resolution of symptoms at follow-up. CONCLUSION We review the literature regarding the etiology, pathogenesis, and management of these lesions. While iatrogenic injuries to the STA have been previously reported, this is a curious case related to placement of an intracranial pressure monitor. We recommend direct surgical resection of the pseudoaneurysm for cosmetic effect and prevention of further wound breakdown.