Rachel Grossman

Outcome of Elderly Patients Undergoing Awake-Craniotomy for Tumor Resection

BackgroundAwake-craniotomy allows maximal tumor resection, which has been associated with extended survival. The feasibility and safety of awake-craniotomy and the effect of extent of resection on survival in the elderly population has not been established. The aim of this study was to compare surgical outcome of elderly patients undergoing awake-craniotomy to that of younger patients.MethodsOutcomes of consecutive patients younger and older than 65xa0years who underwent awake-craniotomy at a single institution between 2003 and 2010 were retrospectively reviewed. The groups were compared for clinical variables and surgical outcome parameters, as well as overall survival.ResultsA total of 334 young (45.4xa0±xa013.2xa0years, meanxa0±xa0SD) and 90 elderly (71.7xa0±xa05.1xa0years) patients were studied. Distribution of gender, mannitol treatment, hemodynamic stability, and extent of tumor resection were similar. Significantly more younger patients had a better preoperative Karnofsky Performance Scale score (>70) than elderly patients (Pxa0=xa00.0012). Older patients harbored significantly more high-grade gliomas (HGG) and brain metastases, and fewer low-grade gliomas (Pxa0<xa00.0001). No significantly higher rate of mortality, or complications were observed in the elderly group. Age was associated with increased length of stay (4.9xa0±xa06.3 vs. 6.6xa0±xa07.5xa0days, Pxa0=xa00.01). Maximal extent of tumor resection in patients with HGG was associated with prolonged survival in the elderly patients.ConclusionsAwake-craniotomy is a well-tolerated and safe procedure, even in elderly patients. Gross total tumor resection in elderly patients with HGG was associated with prolonged survival. The data suggest that favorable prognostic factors for patients with malignant brain tumors are also valid in elderly patients.

Restoring the oncosuppressor activity of microRNA-34a in glioblastoma using a polyglycerol-based polyplex

Glioblastoma multiforme (GBM) is the most common and aggressive primary neoplasm of the brain. Poor prognosis is mainly attributed to tumor heterogeneity, invasiveness, and drug resistance. microRNA-based therapeutics represent a promising approach due to their ability to inhibit multiple targets. In this work, we aim to restore the oncosuppressor activity of microRNA-34a (miR-34a) in GBM. We developed a cationic carrier system, dendritic polyglycerolamine (dPG-NH2), which remarkably improves miRNA stability, intracellular trafficking, and activity. dPG-NH2 carrying mature miR-34a targets C-MET, CDK6, Notch1 and BCL-2, consequently inhibiting cell cycle progression, proliferation and migration of GBM cells. Following complexation with dPG-NH2, miRNA is stable in plasma and able to cross the blood–brain barrier. We further show inhibition of tumor growth following treatment with dPG-NH2–miR-34a in a human glioblastoma mouse model. We hereby present a promising technology using dPG-NH2–miR-34a polyplex for brain-tumor treatment, with enhanced efficacy and no apparent signs of toxicity.

The Dark Side of Nrf2

alignant gliomas are the most aggressive and lethal form of brain cancer, with median survival of patients M with glioblastoma multiforme (GBM) of less than 2 years even after maximal treatment (2). The invasive nature of malignant gliomas is a major barrier to their effective clinical treatment, preventing complete tumor resection, making curative treatment impossible, and ultimately leading to the patient’s death (4). Thus, one of the most challenging issues in glioma biology and developmental therapeutics is the identification of the mechanisms responsible for glioma cell infiltration.

Co-targeting the tumor endothelium and P-selectin-expressing glioblastoma cells leads to a remarkable therapeutic outcome

Glioblastoma is a highly aggressive brain tumor. Current standard-of-care results in a marginal therapeutic outcome, partly due to acquirement of resistance and insufficient blood-brain barrier (BBB) penetration of chemotherapeutics. To circumvent these limitations, we conjugated the chemotherapy paclitaxel (PTX) to a dendritic polyglycerol sulfate (dPGS) nanocarrier. dPGS is able to cross the BBB, bind to P/L-selectins and accumulate selectively in intracranial tumors. We show that dPGS has dual targeting properties, as we found that P-selectin is not only expressed on tumor endothelium but also on glioblastoma cells. We delivered dPGS-PTX in combination with a peptidomimetic of the anti-angiogenic protein thrombospondin-1 (TSP-1 PM). This combination resulted in a remarkable synergistic anticancer effect on intracranial human and murine glioblastoma via induction of Fas and Fas-L, with no side effects compared to free PTX or temozolomide. This study shows that our unique therapeutic approach offers a viable alternative for the treatment of glioblastoma.

A non-aggressive, highly efficient, enzymatic method for dissociation of human brain-tumors and brain-tissues to viable single-cells

Background Conducting research on the molecular biology, immunology, and physiology of brain tumors (BTs) and primary brain tissues requires the use of viably dissociated single cells. Inadequate methods for tissue dissociation generate considerable loss in the quantity of single cells produced and in the produced cells’ viability. Improper dissociation may also demote the quality of data attained in functional and molecular assays due to the presence of large quantities cellular debris containing immune-activatory danger associated molecular patterns, and due to the increased quantities of degraded proteins and RNA.ResultsOver 40 resected BTs and non-tumorous brain tissue samples were dissociated into single cells by mechanical dissociation or by mechanical and enzymatic dissociation. The quality of dissociation was compared for all frequently used dissociation enzymes (collagenase, DNase, hyaluronidase, papain, dispase) and for neutral protease (NP) from Clostridium histolyticum. Single-cell-dissociated cell mixtures were evaluated for cellular viability and for the cell-mixture dissociation quality. Dissociation quality was graded by the quantity of subcellular debris, non-dissociated cell clumps, and DNA released from dead cells. Of all enzymes or enzyme combinations examined, NP (an enzyme previously not evaluated on brain tissues) produced dissociated cell mixtures with the highest mean cellular viability: 93xa0% in gliomas, 85xa0% in brain metastases, and 89xa0% in non-tumorous brain tissue. NP also produced cell mixtures with significantly less cellular debris than other enzymes tested. Dissociation using NP was non-aggressive over time—no changes in cell viability or dissociation quality were found when comparing 2-h dissociation at 37xa0°C to overnight dissociation at ambient temperature.ConclusionsThe use of NP allows for the most effective dissociation of viable single cells from human BTs or brain tissue. Its non-aggressive dissociative capacity may enable ambient-temperature shipping of tumor pieces in multi-center clinical trials, meanwhile being dissociated. As clinical grade NP is commercially available it can be easily integrated into cell-therapy clinical trials in neuro-oncology. The high quality viable cells produced may enable investigators to conduct more consistent research by avoiding the experimental artifacts associated with the presence dead cells or cellular debris.

Recursive Partitioning Analysis (RPA) Classification Predicts Survival in Patients with Brain Metastases from Sarcoma

OBJECTIVEnSarcoma rarely metastasizes to the brain, and there are no specific treatment guidelines for these tumors. The recursive partitioning analysis (RPA) classification is a well-established prognostic scale used in many malignancies. In this study we assessed the clinical characteristics of metastatic sarcoma to the brain and the validity of the RPA classification system in a subset of 21 patients who underwent surgical resection of metastatic sarcoma to the brainnnnMETHODSnWe retrospectively analyzed the medical, radiological, surgical, pathological, and follow-up clinical records of 21 patients who were operated for metastatic sarcoma to the brain between 1996 and 2012. Gliosarcomas, sarcomas of the head and neck with local extension into the brain, and metastatic sarcomas to the spine were excluded from this reported series.nnnRESULTSnThe patients mean age was 49.6 ± 14.2 years (range, 25-75 years) at the time of diagnosis. Sixteen patients had a known history of systemic sarcoma, mostly in the extremities, and had previously received systemic chemotherapy and radiation therapy for their primary tumor. The mean maximal tumor diameter in the brain was 4.9 ± 1.7 cm (range 1.7-7.2 cm). The groups median preoperative Karnofsky Performance Scale was 80, with 14 patients presenting with Karnofsky Performance Scale of 70 or greater. The median overall survival was 7 months (range 0.2-204 months). The median survival time stratified by the Radiation Therapy Oncology Group RPA classes were 31, 7, and 2 months for RPA class I, II, and III, respectively (P = 0.0001).nnnCONCLUSIONSnThis analysis is the first to support the prognostic utility of the Radiation Therapy Oncology Group RPA classification for sarcoma brain metastases and may be used as a treatment guideline tool in this rare disease.

Multimodal Treatment of Hemorrhagic Pituitary Metastasis as First Manifestation of Renal Cell Carcinoma

BACKGROUNDnMetastatic tumors involving the pituitary gland are very rare, with only few cases reported so far in the literature.nnnCASE DESCRIPTIONnWe report a case of a man who presented with an extremely vascular hemorrhagic pituitary metastasis as the first manifestation of renal cell carcinoma. The patient was successfully treated with staged procedures, including preoperative tumor vasculature embolization followed by transsphenoidal tumor resection.nnnCONCLUSIONSnThis is the first report describing multimodality treatment of a patient with pituitary metastasis of unknown origin requiring presurgical embolization before successful tumor removal.

Dysphagia as a Complication of Posterior Fossa Surgery in Adults

Dysphagia is a swallowing dysfunction and a known complication after posterior fossa surgery. It may lead to aspiration, dehydration, and malnutrition, all lifethreatening complications. Swallowing is a complex process that is activated in several phases, each involving both sensory and motor fibers. To understand the implications of dysphagia, we will briefly review the anatomy and physiology of the swallowing process. The first phase is the oral preparatory stage, or food mastication starting after the food is introduced into the mouth. This stage involves the trigeminal nerve that innervates the mastication muscles, the facial nerve that innervates the labial and buccinator muscles, and the hypoglossal nerve that innervates the tongue to move the food to the posterior teeth. This is followed by the oral stage, when the food is moved to the posterior part of the oral cavity, mainly controlled by the tongue (hypoglossal nerve). The third part is the pharyngeal stage, a reflex action that transports the food through the pharynx to the esophagus, but not to the nasopharynx or larynx that should be closed, thus protecting the airway from aspiration (mediated by cranial nerves IXeXI). The esophageal stage is a reflexive stage that transports the food by the esophageal peristaltic movement and relaxation of the lower esophageal sphincter (again, mediated by cranial nerves IXeXI). The posterior fossa is a small region containing the brain stem, cerebellum, and fourth ventricle and controls many vital functions, such as speech, hearing, movement, sensation, and swallowing. Expansion of a mass in the posterior fossa occurs at the expense of the normal structures in the region and may result in brain stem or cerebellar dysfunction. Less than 5% of all adult tumors originate in the posterior fossa, whereas approximately 50% of primary central nervous system tumors occurring in

Image-guided surgery using near-infrared Turn-ON fluorescent nanoprobes for precise detection of tumor margins

Complete tumor removal during surgery has a great impact on patient survival. To that end, the surgeon should detect the tumor, remove it and validate that there are no residual cancer cells left behind. Residual cells at the incision margin of the tissue removed during surgery are associated with tumor recurrence and poor prognosis for the patient. In order to remove the tumor tissue completely with minimal collateral damage to healthy tissue, there is a need for diagnostic tools that will differentiate between the tumor and its normal surroundings. Methods: We designed, synthesized and characterized three novel polymeric Turn-ON probes that will be activated at the tumor site by cysteine cathepsins that are highly expressed in multiple tumor types. Utilizing orthotopic breast cancer and melanoma models, which spontaneously metastasize to the brain, we studied the kinetics of our polymeric Turn-ON nano-probes. Results: To date, numerous low molecular weight cathepsin-sensitive substrates have been reported, however, most of them suffer from rapid clearance and reduced signal shortly after administration. Here, we show an improved tumor-to-background ratio upon activation of our Turn-ON probes by cathepsins. The signal obtained from the tumor was stable and delineated the tumor boundaries during the whole surgical procedure, enabling accurate resection. Conclusions: Our findings show that the control groups of tumor-bearing mice, which underwent either standard surgery under white light only or under the fluorescence guidance of the commercially-available imaging agents ProSense® 680 or 5-aminolevulinic acid (5-ALA), survived for less time and suffered from tumor recurrence earlier than the group that underwent image-guided surgery (IGS) using our Turn-ON probes. Our smart polymeric probes can potentially assist surgeons decision in real-time during surgery regarding the tumor margins needed to be removed, leading to improved patient outcome.

Abstract B05: Patient-derived GBM tumors versus patient-derived primary cells and GBM cell lines: lessons from microRNA profiling

Glioblastoma multiforme is a very heterogeneous tumor, highly infiltrative, angiogenic and resistant to standard therapeutic intervention. Experimental models currently used in research are mostly based on cancer cell lines, which are grown in culture for many generations and have lost many essential biological characteristics. In consequence, the xenograft tumor models derived from those cells do not maintain genomic and phenotypic characteristics present in the original tumor. It is questionable whether these artificial preclinical models can serve as reliable platforms to select the lead candidate for a novel therapeutic approach. We utilized miRNA expression patterns to evaluate the clinical relevance of some of the currently available experimental models of GBM, searching for similarities and differences in miRNA expression levels between freshly isolated tumors, patient-derived primary cells and GBM cell lines grown in culture. The study included 22 formalin-fixed paraffin-embedded (FFPE) tumors from glioblastoma resections. Those were divided into two groups of Short Term Survivors (STS, survived up to 3 months from initial diagnosis; n=12) and Long Term Survivors (LTS, survived more than 3 years from initial diagnosis; n=10).We further tested 6 patient-derived primary cells, and 5 ATCC human GBM cell lines widely used in preclinical research. Two of the cell lines included dormant and fast-growing variants previously developed in our laboratory to resemble LTS and STS phenotypes, respectively. Samples were loaded on custom microRNA (miR) arrays, including 2172 known miRNAs (miRBase 19). We found several miRNAs that were upregulated in the STS samples while others exhibited higher expression levels in the LTS samples. Both GBM cell lines and patient-derived primary cells exhibited a miRNA profile which was very different from patient samples. Brain miRNAs used as brain markers, such as hsa-miR-124-3p), show relatively low expression levels in both patient-derived primary cells and commercial cell lines but are highly expressed in tumors. We concluded that GBM experimental models must be reevaluated and pre-clinical findings derived from long-established and commonly used in vitro and in vivo models should be further validated in patient-derived models that are more suitable to evaluate the potential clinical relevance of new therapeutics. Citation Format: Paula Ofek, Nir Dromi, Noga Yerushalmi, Sharon Kredo-Russo, Rachel Grossman, Zvi Ram, Ronit Satchi-Fainaro. Patient-derived GBM tumors versus patient-derived primary cells and GBM cell lines: lessons from microRNA profiling. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B05.