ZEB1 loss increases glioma stem cell tumorigenicity and resistance to chemoradiation

OBJECTIVE

Glioblastoma has been known to be resistant to chemotherapy and radiation, whereas the underlying mechanisms of resistance have not been fully elucidated. The authors studied the role of the transcription factor ZEB1 (zinc finger E-box-binding homeobox 1 protein), which is associated with epithelial-mesenchymal transition (EMT) and is central to the stemness of glioblastoma, to determine its role in therapeutic resistance to radiation and chemotherapy. The authors previously demonstrated that ZEB1 is deleted in a majority of glioblastomas.

METHODS

The authors explored resistance to therapy in the context of ZEB1 loss and overexpression in glioma stem cells (GSCs) and in patient data.

RESULTS

Patients with ZEB1 loss had a shorter survival time than patients with wild-type ZEB1 in both the high- and low-MGMT groups. Consistent with the clinical data, mice implanted with ZEB1 knockdown GSCs showed shortened survival compared with mice inoculated with nonsilencing control (NS) short-hairpin RNA (shRNA) GSC glioblastoma. ZEB1-deleted GSCs demonstrated increased tumorigenicity with regard to proliferation and invasion. Importantly, GSCs that lose ZEB1 expression develop enhanced resistance to chemotherapy, radiotherapy, and combined chemoradiation. ZEB1 loss may lead to increased HER3 expression through the HER3/Akt pathway associated with this chemoresistance. Conversely, overexpression of ZEB1 in GSCs that are ZEB1 null leads to increased sensitivity to chemoradiation.

CONCLUSIONS

The study results indicate that ZEB1 loss in cancer stem cells confers resistance to chemoradiation and uncovers a potentially targetable cell surface receptor in these resistant cells.

A Phase I Study of Autologous Dendritic Cell Vaccine Pulsed with Allogeneic Stem-like Cell Line Lysate in Patients with Newly Diagnosed or Recurrent Glioblastoma

BACKGROUND

Glioblastoma is a heterogeneous malignancy with multiple subpopulations of cancer cells present within any tumor. We present the results of a phase 1 clinical trial utilizing an autologous dendritic cell vaccine pulsed with lysate derived from a glioblastoma stem-like cell line.

METHODS

Patients with newly diagnosed and recurrent glioblastoma were enrolled as separate cohorts. Eligibility criteria included a qualifying surgical resection or minimal tumor size, less than or equal to 4 mg dexamethasone daily dose, and Karnofsky score greater than or equal to 70. Vaccine treatment consisted of two phases: An induction phase with vaccine given weekly for 4 weeks, and a maintenance phase with vaccines administered every 8 weeks until depletion of supply or disease progression. Patients with newly diagnosed glioblastoma also received standard-of-care radiation and temozolomide. The primary objective for this open-label, single-institution trial was to assess the safety and tolerability of the autologous dendritic cell vaccine.

RESULTS

For the 11 patients with newly diagnosed glioblastoma, median PFS was 8.75 months, and median OS was 20.36 months. For the 25 patients with recurrent glioblastoma, median PFS was 3.23 months, 6-month PFS was 24%, and median survival was 11.97 months. A subset of patients developed a cytotoxic T cell response as determined by an IFNγ ELISpot assay.

CONCLUSIONS

In this trial, treatment of newly diagnosed and recurrent glioblastoma with autologous dendritic cell vaccine pulsed with lysate derived from an allogeneic stem-like cell line was safe and well-tolerated. Clinical outcomes add to the body of evidence suggesting that immunotherapy plays a role in the treatment of glioblastoma.

Blockade of a Laminin-411-Notch Axis with CRISPR/Cas9 or a Nanobioconjugate Inhibits Glioblastoma Growth through Tumor-Microenvironment Cross-talk

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (α4β1γ1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma.Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.

Adult Brainstem Glioblastoma Multiforme: Long-term Survivor

Adult, malignant brainstem gliomas are rare entities that often cause treatment conundrums due to the difficulty of surgical resection and, therefore, the absence of pathological diagnosis. This leads to a reliance on radiological imaging for diagnosis, which can often be unreliable. These shortcomings have made the treatment of brainstem gliomas challenging with unpredictable outcomes. The mainstay of treatment consists of chemotherapy and radiation; however, recurrence is inevitable. Predicting outcomes has been the major difficulty in treating these patients as adult malignant brainstem gliomas Grade II have a median survival between five to seven years while Grades III and IV are between 10-17 months (with some studies showing significantly longer survival in Grade III). Here, we present the case of a patient with the pathologic diagnosis of a right brachium pontis glioblastoma who had a remarkable survival of 73 months, whereas the expected median survival for these patients is 10-17 months.

Retrospective analysis of the tolerability and activity of lacosamide in patients with brain tumors

Object

The object of this study was to determine the tolerability and activity of lacosamide in patients with brain tumors.

Methods

The authors reviewed the medical records at 5 US academic medical centers with tertiary brain tumor programs, seeking all patients in whom a primary brain tumor had been diagnosed and who were taking lacosamide.

Results

The authors identified 70 patients with primary brain tumors and reviewed seizure frequency and toxicities. The majority of the patients had gliomas (96%). Fifty-five (78%) had partial seizures only, and 12 (17%) had generalized seizures. Most of the patients (74%) were started on lacosamide because of recurrent seizures. Forty-six patients (66%) reported a decrease in seizure frequency, and 21 patients (30%) reported stable seizures. Most of the patients (54 [77%]) placed on lacosamide did not report any toxicities.

Conclusions

This retrospective analysis demonstrated that lacosamide was both well tolerated and active as an add-on antiepileptic drug (AED) in patients with brain tumors. Lacosamide's novel mechanism of action will allow for concurrent use with other AEDs, as documented by its activity across many different types of AEDs used in this patient population. Larger prospective studies are warranted.

Hospital layoffs. One facility's experience with a work force reduction

In 1994 the conversion of Tennessee's Medicaid program to managed care sharply reduced the census of all Memphis hospitals, including St. Joseph Hospital and Health Care Centers. St. Joseph's Operations Leadership group (OLG) decided that expenditures must be cut by $8 million-$6 million of it coming from wages and salaries--so the hospital could enter fiscal year 1995 with a balanced budget. With the help of a consulting firm, the OLG determined that the wage and salary cuts could be realized by laying off a certain number of employees. All workers were told, in a series of round-the-clock meetings, that 162 jobs (22 managers and 140 hourly workers) would be eliminated in nine days. The hospital's labor relations attorney approved the criteria according to which workers would be dismissed. On the designated days (one for managers, another for rank-and-file workers), the layoffs were completed in an organized manner. The OLG had arranged with a private firm to set up a career placement center for the dismissed employees. Of the 162, 105 took advantage of the center's services. Thirty-five of those (21 percent) had new jobs within 45 days of the layoffs. The OLG was straightforward with the local media about the layoffs. Hospital leaders calmed remaining St. Joseph workers' anxieties with a series of follow-up meetings. These sessions also provided the OLG with useful feedback on the way it had conducted the layoffs.

The direct effect of health managers on quality control, assessment, assurance

In the midst of the many changes that are occurring in the health industry, the pursuit of quality remains a constant. In the past, efforts at quality control have largely focused on the provision of clinical care. In this article, the authors discuss the role of health managers in the provision of quality care beyond the clinical environment in the area of guest services. Additionally, they review how to improve the organizational climate in which services are provided and measure the results.

A process and considerations for activating a quality/productivity monitoring system

In response to demands for cost containment in operational areas without subsequent declines in quality, many hospitals are implementing quality and productivity monitoring systems. This article describes the process used by St. Elizabeth Hospital Medical Center (SEHMC), Youngstown, Ohio, to determine that it would use an outside consultant, select a consultant, negotiate the contract and implement the program. The article offers practical advice for other hospitals considering using outside services for developing quality/productivity monitoring systems as well as other projects.