CD57 defines a novel cancer stem cell that drive invasion of diffuse pediatric-type high grade gliomas

BACKGROUND

Diffuse invasion remains a primary cause of treatment failure in pediatric high-grade glioma (pHGG). Identifying cellular driver(s) of pHGG invasion is needed for anti-invasion therapies.

METHODS

Ten highly invasive patient-derived orthotopic xenograft (PDOX) models of pHGG were subjected to isolation of matching pairs of invasive (HGGINV) and tumor core (HGGTC) cells.

RESULTS

pHGGINV cells were intrinsically more invasive than their matching pHGGTC cells. CSC profiling revealed co-positivity of CD133 and CD57 and identified CD57+CD133- cells as the most abundant CSCs in the invasive front. In addition to discovering a new order of self-renewal capacities, i.e., CD57+CD133- > CD57+CD133+ > CD57-CD133+ > CD57-CD133- cells, we showed that CSC hierarchy was impacted by their spatial locations, and the highest self-renewal capacities were found in CD57+CD133- cells in the HGGINV front (HGGINV/CD57+CD133- cells) mediated by NANOG and SHH over-expression. Direct implantation of CD57+ (CD57+/CD133- and CD57+/CD133+) cells into mouse brains reconstituted diffusely invasion, while depleting CD57+ cells (i.e., CD57-CD133+) abrogated pHGG invasion.

CONCLUSION

We revealed significantly increased invasive capacities in HGGINV cells, confirmed CD57 as a novel glioma stem cell marker, identified CD57+CD133- and CD57+CD133+ cells as a new cellular driver of pHGG invasion and suggested a new dual-mode hierarchy of HGG stem cells.

Direct Implantation of Patient Brain Tumor Cells into Matching Locations in Mouse Brains for Patient-Derived Orthotopic Xenograft Model Development

Background: Despite multimodality therapies, the prognosis of patients with malignant brain tumors remains extremely poor. One of the major obstacles that hinders development of effective therapies is the limited availability of clinically relevant and biologically accurate (CRBA) mouse models. Methods: We have developed a freehand surgical technique that allows for rapid and safe injection of fresh human brain tumor specimens directly into the matching locations (cerebrum, cerebellum, or brainstem) in the brains of SCID mice. Results: Using this technique, we successfully developed 188 PDOX models from 408 brain tumor patient samples (both high-and low-grade) with a success rate of 72.3% in high-grade glioma, 64.2% in medulloblastoma, 50% in ATRT, 33.8% in ependymoma, and 11.6% in low-grade gliomas. Detailed characterization confirmed their replication of the histopathological and genetic abnormalities of the original patient tumors. Conclusions: The protocol is easy to follow, without a sterotactic frame, in order to generate large cohorts of tumor-bearing mice to meet the needs of biological studies and preclinical drug testing.

Patient-Derived Models of Cancer in the NCI PDMC Consortium: Selection, Pitfalls, and Practical Recommendations

For over a century, early researchers sought to study biological organisms in a laboratory setting, leading to the generation of both in vitro and in vivo model systems. Patient-derived models of cancer (PDMCs) have more recently come to the forefront of preclinical cancer models and are even finding their way into clinical practice as part of functional precision medicine programs. The PDMC Consortium, supported by the Division of Cancer Biology in the National Cancer Institute of the National Institutes of Health, seeks to understand the biological principles that govern the various PDMC behaviors, particularly in response to perturbagens, such as cancer therapeutics. Based on collective experience from the consortium groups, we provide insight regarding PDMCs established both in vitro and in vivo, with a focus on practical matters related to developing and maintaining key cancer models through a series of vignettes. Although every model has the potential to offer valuable insights, the choice of the right model should be guided by the research question. However, recognizing the inherent constraints in each model is crucial. Our objective here is to delineate the strengths and limitations of each model as established by individual vignettes. Further advances in PDMCs and the development of novel model systems will enable us to better understand human biology and improve the study of human pathology in the lab.

Silencing GMPPB Inhibits the Proliferation and Invasion of GBM via Hippo/MMP3 Pathways

Glioblastoma multiforme (GBM) is a highly aggressive malignancy and represents the most common brain tumor in adults. To better understand its biology for new and effective therapies, we examined the role of GDP-mannose pyrophosphorylase B (GMPPB), a key unit of the GDP-mannose pyrophosphorylase (GDP-MP) that catalyzes the formation of GDP-mannose. Impaired GMPPB function will reduce the amount of GDP-mannose available for O-mannosylation. Abnormal O-mannosylation of alpha dystroglycan (α-DG) has been reported to be involved in cancer metastasis and arenavirus entry. Here, we found that GMPPB is highly expressed in a panel of GBM cell lines and clinical samples and that expression of GMPPB is positively correlated with the WHO grade of gliomas. Additionally, expression of GMPPB was negatively correlated with the prognosis of GBM patients. We demonstrate that silencing GMPPB inhibits the proliferation, migration, and invasion of GBM cells both in vitro and in vivo and that overexpression of GMPPB exhibits the opposite effects. Consequently, targeting GMPPB in GBM cells results in impaired GBM tumor growth and invasion. Finally, we identify that the Hippo/MMP3 axis is essential for GMPPB-promoted GBM aggressiveness. These findings indicate that GMPPB represents a potential novel target for GBM treatment.

Targeting GBM with an Oncolytic Picornavirus SVV-001 alone and in combination with fractionated Radiation in a Novel Panel of Orthotopic PDX models

BACKGROUND

Animal models representing different molecular subtypes of glioblastoma multiforme (GBM) is desired for developing new therapies. SVV-001 is an oncolytic virus selectively targeting cancer cells. It's capacity of passing through the blood brain barrier makes is an attractive novel approach for GBM.

MATERIALS AND METHODS

23 patient tumor samples were implanted into the brains of NOD/SCID mice (1 × 105 cells/mouse). Tumor histology, gene expression (RNAseq), and growth rate of the developed patient-derived orthotopic xenograft (PDOX) models were compared with the originating patient tumors during serial subtransplantations. Anti-tumor activities of SVV-001 were examined in vivo; and therapeutic efficacy validated in vivo via single i.v. injection (1 × 1011 viral particle) with or without fractionated (2 Gy/day x 5 days) radiation followed by analysis of animal survival times, viral infection, and DNA damage.

RESULTS

PDOX formation was confirmed in 17/23 (73.9%) GBMs while maintaining key histopathological features and diffuse invasion of the patient tumors. Using differentially expressed genes, we subclassified PDOX models into proneural, classic and mesenchymal groups. Animal survival times were inversely correlated with the implanted tumor cells. SVV-001 was active in vitro by killing primary monolayer culture (4/13 models), 3D neurospheres (7/13 models) and glioma stem cells. In 2/2 models, SVV-001 infected PDOX cells in vivo without harming normal brain cells and significantly prolonged survival times in 2/2 models. When combined with radiation, SVV-001 enhanced DNA damages and further prolonged animal survival times.

CONCLUSION

A panel of 17 clinically relevant and molecularly annotated PDOX modes of GBM is developed, and SVV-001 exhibited strong anti-tumor activities in vitro and in vivo.

Stand-alone optical spinning tweezers with tunable rotation frequency

Advances in optical trapping design principles have led to tremendous progress in manipulating nanoparticles (NPs) with diverse functionalities in different environments using bulky systems. However, efficient control and manipulation of NPs in harsh environments require a careful design of contactless optical tweezers. Here, we propose a simple design of a fibered optical probe allowing the trapping of dielectric NP as well as a transfer of the angular momentum of light to the NP inducing its mechanical rotation. A polarization conversion from linearly-polarized incident guided to circularly transmitted beam is provoked geometrically by breaking the cylindrical symmetry of a coaxial nano-aperture that is engraved at the apex of a tapered metal coated optical fiber. Numerical simulations show that this simple geometry tip allows powerful light transmission together with efficient polarization conversion. This guarantees very stable trapping of quasi spherical NPs in a non-contact regime as well as potentially very tunable and reversible rotation frequencies in both directions (up to 45 Hz in water and 5.3 MHz in air for 10 mW injected power in the fiber). This type of fiber probe opens the way to a new generation of miniaturized tools for total manipulation (trapping, sorting, spinning) of NPs.

Expression of caveolin-1 in tooth germ, ameloblastoma and ameloblastic carcinoma

BACKGROUND

The caveolin-1 protein (structural component of membrane caveolae) plays important roles in several biological functions, such as endocytosis, cell adhesion, and cell signaling. However, this protein has been associated with mechanisms of tumorigenesis in several neoplasms. The expression patterns and roles of caveolin-1 in the oral epithelium and in embryonic and odontogenic tumor tissues are still unclear.

MATERIAL AND METHODS

The expression of caveolin-1 was evaluated in samples of the normal gingival epithelium (n=7), human tooth germ (TG) (n=12), ameloblastoma (AM) (n=83), and ameloblastic carcinoma (AC) (n=9) by immunohistochemistry. Additionally, AM samples were analyzed by qRT-PCR and Western blot.

RESULTS

Most TG (91.7%), AM (73.5%) and AC (100%) samples showed diverse patterns of immunohistochemical positivity for caveolin-1, while only one gingival sample was positive. The transcript levels of cav-1 were significantly upregulated by 14.9-fold in AM tissue (P = 0.0014) compared to those in normal gingival epithelial tissue, as shown by qRT-PCR. Presence of caveolin-1 protein was confirmed by Western blot analysis. The caveolin-1 immunoexpression patterns throughout the stages of TG show its importance during odontogenesis.

CONCLUSIONS

The overexpression of caveolin-1 in AM and AC compared to its expression in normal gingival epithelium (adult tissue) suggests a possible role of caveolin-1 in protumoral events, but due to the similar immunoexpression observed in AM and AC, caveolin-1 may not necessarily participate in the malignant transformation process. However, future studies are needed to clarify and confirm these hypotheses.

Louis E, Suarez M, Boeve B, Silber M, Low P, Singer W. 0787 Autonomic Dysfunction and Phenoconversion in Idiopathic/Isolated REM Sleep Behavior Disorder

Introduction

REM-sleep behavior disorder (RBD) is a common finding among patients with synucleinopathies. We aimed to determine the degree of autonomic dysfunction in patients presenting with idiopathic RBD (iRBD), and the predictive value of autonomic dysfunction for phenoconversion to a defined neurodegenerative disease.

Methods

We searched our electronic medical record for patients diagnosed with iRBD who also underwent standardized autonomic function testing within 6 months of iRBD diagnosis, and who had clinical follow-up of at least 3 years following iRBD diagnosis. Patients who received a diagnosis of phenoconversion within 3 months of autonomic testing were excluded. The composite autonomic severity score (CASS) was derived and compared between phenoconverters and non-converters using chi-square and Wilcoxon rank-sum tests.

Results

We identified 18 patients who fulfilled in- and exclusion criteria. Average age at autonomic testing was 67 ± 6.6 years. Twelve (67%) patients phenoconverted during the follow-up period; 6 developed PD, the other 6 DLB. Fifteen (83%) patients had at least mild autonomic dysfunction. There were no significant differences between overall converters and non-converters in total CASS or CASS subscores. However, iRBD patients who developed DLB had significantly higher total and cardiovagal CASS scores compared with those who developed PD (p <0.05), and a trend for higher adrenergic CASS scores compared to those who developed PD and those who did not phenoconvert (p=0.08 for each).

Conclusion

Autonomic dysfunction was seen in 83% of iRBD patients, and more severe baseline cardiovagal and adrenergic autonomic dysfunction in iRBD was associated with phenoconversion to DLB but not PD. Prospective studies are needed to confirm the value of autonomic testing for predicting phenoconversion and disease phenotype in iRBD.

Support

 

Validation of a clinical decision tree to predict if a patient has a bacteraemia due to a β-lactamase producing organism

BACKGROUND

In recent years, several scores and algorithms have been developed in order to guide empirical antibiotic treatment in patients with gram-negative bacilli (GNB) bacteraemia according to the risk of extended-spectrum β-lactamase (BL) producing. Some of these algorithms do not have easy applicability or present some limitations in their validation. The aim of our study was to validate a recently designed decision tree in our prospective cohort of bacteraemia due to gram-negative bacilli.

METHODS

We prospectively identified and analyzed all bacteraemia due to gram-negative bacilli in adult patients in our centre between January 2015 and December 2016. Previously developed clinical decision tree was used to classify patients in each of the terminal nodes. Patients were classified as BL group according to whether they were producers of any type of BL. The statistical power of the tree was analyzed by receiver operating characteristics (ROC) curve and by calculation of C-statistics.

RESULTS

A total of 448 episodes of bacteraemia were included; 132 (29.5%) were BL group; 68 (15.1%) ESBL producing, 43 (9.6%) due to AmpC and 21 (4.7%) isolates of Pseudomonas aeruginosa. The original clinical decision tree was modified according to the results of our multivariate analysis. The modified tree has a sensitivity of 71%, specificity of 92%, predictive positive value (PPV) of 79% and predictive negative value (NPV) of 88% generating an ROC curve with a C-statistic of 0.76.

CONCLUSIONS

An easy-to-apply clinical decision tree could be used at the exact moment of diagnosis and adjust the empirical antibiotic treatment in patients with gram-negative bacilli bacteraemia.

Abstract P5-22-10: Intraoperative ultrasound guided surgery after neoadjuvant treatment in breast cancer improves patient´s quality of life

Background: Intraoperative ultrasound guided surgery (IOUS) has shown not only to improve surgical outcomes by achieving higher rates of negative margins and reducing the need for re-excisions, but also showing better cosmetic results and patient's satisfaction in the adjuvant setting. After neoadjuvant treatments (NAT) we have shown that IOUS lowers the volume of resection in patients with pathologic complete response or minimal microscopic disease after NAT without compromising margins and local recurrences when compared to wire localization techniques (WL) The aim of this study was to determine if IOUS after NAT contributes to improve cosmetic outcomes and quality of life (QOL) when compared with WL.

Material and Methods. The pilot study enrolled patients treated with NAT who underwent breast-conserving surgery (BCS) between July 2008 and December 2012. On the follow up visit, cosmetic outcomes were assessed by the patient and surgeon on a 4 point Likert scale, by the Breast Cancer Conservative Treatment cosmetic results (BCCT.core) software, and by an independent panel. QOL was assessed using cancer-specific (EORTC QLQ-C30 and EORTC QLQ-B23) questionnaires.

Results. The study investigated 113 patients: 81 (71.6 %) in the IOUS group and 32 (28.3 %) in the WL group. The patient and tumor characteristics were comparable between the two groups. Mean follow up was 64 months (range, 12-90) in the WL group while 41 months (range, 18-107) in the IOUS group.

Cosmetic outcomes reported by the patient showed a tendency (p=0.07) for better results in the IOUS group. Patient reported cosmetic outcomes and the independent panel cosmetic evaluation significantly correlated with lumpectomy volume excised (p= 0.04, p = 0.02 respectively). The BCCT.core did not correlate with volume of tissue excised (p < 0.14). IOUS achieved better cosmetic outcomes compared to WL, with excellent outcomes of 30% and 19% respectively, although poor cosmetic outcomes were 3% and 0% respectively. Correlation between patients and surgeons evaluation regarding cosmetic outcomes and satisfaction was low (0.38 and 0.40 respectively). A comparison of the QOL scores of 113 patients showed a significantly better global health status (p = 0.03), better emotional and role function (p = 0.004), for patients with IOUS compared to WL patients.

Conclusions. This is the first study to show that breast volume excised significantly correlates with cosmetic outcomes in the neoadjuvant setting. These results suggest that IOUS after NAT contributes to a better quality of life and may influence cosmetic outcomes in breast cancer patients. Patient reported outcomes should be included in the quality assessment in breast surgery as the correlation with surgeons' evaluation is low.

Citation Format: Rubio IT, Rodriguez R, Esgueva-Colmenarejo A, Suarez M, Espinosa-Bravo M, Siso C, Cordoba O, Alvarado S, Volders J, Van Den Tol P. Intraoperative ultrasound guided surgery after neoadjuvant treatment in breast cancer improves patient´s quality of life [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-10.

Patterns of biofilm structure and formation kinetics among Acinetobacter baumannii clinical isolates with different antibiotic resistance profiles

This study evaluates the rates of biofilm formation in light of the different characteristics of twelve A. baumannii clinical isolates.