Ligand-Dependent and Ligand-Independent Effects of Ephrin-B2-EphB4 Signaling in Melanoma Metastatic Spine Disease.

Tumor-endothelial cell interactions represent an essential mechanism in spinal metastasis. Ephrin-B2-EphB4 communication induces tumor cell repulsion from the endothelium in metastatic melanoma, reducing spinal bone metastasis formation. To shed further light on the Ephrin-B2-EphB4 signaling mechanism, we researched the effects of pharmacological EphB4 receptor stimulation and inhibition in a ligand-dependent/independent context. We chose a preventative and a post-diagnostic therapeutic window. EphB4 stimulation during tumor cell seeding led to an increase in spinal metastatic loci and number of disseminated melanoma cells, as well as earlier locomotion deficits in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, reduction of metastatic loci with a later manifestation of locomotion deficits occurred. Thus, EphB4 receptor stimulation affects metastatic dissemination depending on the presence/absence of endothelial Ephrin-B2. After the manifestation of solid metastasis, EphB4 kinase inhibition resulted in significantly earlier manifestation of locomotion deficits in the presence of the ligand. No post-diagnostic treatment effect was found in the absence of endothelial Ephrin-B2. For solid metastasis treatment, EphB4 kinase inhibition induced prometastatic effects in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, both therapies showed no effect on the growth of solid metastasis.

In vivo visualization of PARP inhibitor pharmacodynamics.

BACKGROUND[18F]FluorThanatrace ([18F]FTT) is a radiolabeled poly (adenosine diphosphate-ribose) polymerase inhibitor (PARPi) that enables noninvasive quantification of PARP with potential to serve as a biomarker for patient selection for PARPi therapy. Here we report for the first time to our knowledge noninvasive in vivo visualization of drug-target engagement during PARPi treatment.METHODSTwo single-arm, prospective, nonrandomized clinical trials were conducted at the University of Pennsylvania from May 2017 to March 2020. PARP expression in breast cancer was assessed in vivo via [18F]FTT PET before and after initiation of PARPi treatment and in vitro via [125I]KX1 (an analog of [18F]FTT) binding to surgically removed breast cancer.RESULTSThirteen patients had baseline [18F]FTT PET. Nine of these then had resection and in vitro evaluation of [18F]FTT uptake with an analog and uptake was blocked with PARPi. Of the other 4 patients, 3 had [18F]FTT PET uptake, and all had uptake blocked with treatment with a therapeutic PARPi. Initial in vivo [18F]FTT tumor uptake ranged from undetectable to robust. Following initiation of PARPi therapy, [18F]FTT uptake was not detectable above background in all cases. In vitro tumor treatment with a PARPi resulted in 82% reduction in [125I]KX1 binding.CONCLUSION[18F]FTT noninvasively quantifies PARP-1 expression. Early results indicate ability to visualize PARPi drug-target engagement in vivo and suggest the utility of further study to test [18F]FTT PET as a predictive and pharmacodynamic biomarker.TRIAL REGISTRATIONClinicalTrials.gov identifiers NCT03083288 and NCT03846167.FUNDINGMetavivor Translational Research Award, Susan G. Komen for the Cure (CCR 16376362), Department of Defense BC190315, and Abramson Cancer Center Breakthrough Bike Challenge.

Vertebral-specific activation of the CX3CL1/ICAM-1 signaling network mediates non-small-cell lung cancer spinal metastasis by engaging tumor cell-vertebral bone marrow endothelial cell interactions.

Rationale: The spine is one of the most common metastatic sites of non-small cell lung cancer (NSCLC), and NSCLC spinal metastasis results in serious consequences. Metastatic extravasation of disseminated cancer cells including increased invasiveness, adhesion and transendothelial migration is crucial for tumor metastasis. This study aimed to investigate the mechanisms underlying NSCLC spinal metastasis based on the C-X3-C motif chemokine ligand 1- (CX3CL1) and intercellular adhesion molecule-1- (ICAM-1) mediated signaling network. Methods: Immunohistochemistry, western blotting, and reverse transcription-quantitative PCR were conducted to detect the distribution of CX3CL1/ICAM-1 in different organs. Transwell, adhesion, and transendothelial migration assays were performed to evaluate the regulatory effects of CX3CL1/ICAM-1 on NSCLC cell invasion, adhesion, and transendothelial migration in vitro. A spontaneous spinal metastasis mouse model was established via injection of NSCLC cells into the left cardiac ventricle of NOD/SCID mice. The effects of CX3CL1/ICAM-1 on NSCLC spinal metastasis in vivo were validated using bioluminescent, micro-computerized tomography, immunohistochemistry and histological analyses. Results: CX3CL1 expression was specifically higher in vertebral bone compared with limb bones and lung tissue, and was associated with NSCLC spinal metastasis. Mechanically, vertebral bone marrow endothelial cells (VBMECs) enhanced NSCLC cell invasion via CX3CL1 signaling-mediated activation of the PI3K/AKT pathway. Furthermore, we found that VBMECs effectively induced ICAM-1-dependent NSCLC cell adhesion in coordination with platelets through the CX3CL1/ICAM-1/LFA-1 pathway. Meanwhile, CX3CL1 enhanced NSCLC cell transendothelial migration by increasing permeability of VBMECs via ICAM-1-dependent activation of the Src/GEF-H1 pathway. Interestingly, NSCLC cells were indicated to promote CX3CL1 secretion of VBMECs through MAPK14/ADMA17-dependent CX3CL1 release and NF-κB-dependent CX3CL1 synthesis. Based on these findings, we revealed a novel feedback cycle between circulating NSCLC cells and VBMECs mediated by CX3CL1/ICAM-1 signaling. Further disengagement of the CX3CL1/ICAM-1-mediated feedback cycle in vivo significantly restricted metastasis and prolonged mouse survival. Conclusions: Our results indicated a unique feedback cycle between circulating NSCLC cells and VBMECs mediated by CX3CL1/ICAM-1 signaling, which is necessary for NSCLC spinal metastasis. This work provides a new perspective for underlying the mechanisms of NSCLC spinal metastasis and indicates potential novel targets for the prevention of NSCLC spinal metastasis.

Standardized uptake values of 99mTc-MDP in normal vertebrae assessed using quantitative SPECT/CT for differentiation diagnosis of benign and malignant bone lesions.

BACKGROUND: Quantitative bone SPECT/CT is useful for disease follow up and inter-patient comparison. For bone metastatic malignant lesions, spine is the most commonly invaded site. However, Quantitative studies with large sample size investigating all the segments of normal cervical, thoracic and lumbar vertebrae are seldom reported. This study was to evaluate the quantitative tomography of normal vertebrae using 99mTc-MDP with SPECT/CT to investigate the feasibility of standardized uptake value (SUV) for differential diagnosis of benign and malignant bone lesions. METHODS: A retrospective study was carried out involving 221 patients (116 males and 105 females) who underwent SPECT/CT scan using 99mTc-MDP. The maximum SUV (SUVmax), mean SUV (SUVmean) and CT values (Hounsfield Unit, HU) of 2416 normal vertebrae bodies, 157 benign bone lesions and 118 malignant bone metastasis foci were obtained. The correlations between SUVmax of normal vertebrae and CT values of normal vertebrae, age, height, weight, BMI of patients were analyzed. Statistical analysis was performed with data of normal, benign and malignant groups corresponding to same sites and gender. RESULTS: The SUVmax and SUVmean of normal vertebrae in males were markedly higher than those in females (P < 0.0009). The SUVmax of each normal vertebral segment showed a strong negative correlation with CT values in both males and females (r = - 0.89 and - 0.92, respectively; P < 0.0009). The SUVmax of normal vertebrae also showed significant correlation with weight, height, and BMI in males (r = 0.4, P < 0.0009; r = 0.28, P = 0.005; r = 0.22, P = 0.026), and significant correlation with weight and BMI in females (r = 0.32, P = 0.009; r = 0.23, P = 0.031). The SUVmax of normal group, benign bone lesion group and malignant bone metastasis foci group showed statistical differences in both males and females. CONCLUSION: Our study evaluated SUVmax and SUVmean of normal vertebrae, benign bone lesion and malignant bone metastasis foci with a large sample population. Preliminary results proved the potential value of SUVmax in differentiation benign and malignant bone lesions. The results may provide a quantitative reference for clinical diagnosis and the evaluation of therapeutic response in vertebral lesions.

Targeted brachyury degradation disrupts a highly specific autoregulatory program controlling chordoma cell identity.

Chordomas are rare spinal tumors addicted to expression of the developmental transcription factor brachyury. In chordomas, brachyury is super-enhancer associated and preferentially downregulated by pharmacologic transcriptional CDK inhibition, leading to cell death. To understand the underlying basis of this sensitivity, we dissect the brachyury transcription regulatory network and compare the consequences of brachyury degradation with transcriptional CDK inhibition. Brachyury defines the chordoma super-enhancer landscape and autoregulates through binding its super-enhancer, and its locus forms a transcriptional condensate. Transcriptional CDK inhibition and brachyury degradation disrupt brachyury autoregulation, leading to loss of its transcriptional condensate and transcriptional program. Compared with transcriptional CDK inhibition, which globally downregulates transcription, leading to cell death, brachyury degradation is much more selective, inducing senescence and sensitizing cells to anti-apoptotic inhibition. These data suggest that brachyury downregulation is a core tenet of transcriptional CDK inhibition and motivates developing strategies to target brachyury and its autoregulatory feedback loop.

Coexpression of HHLA2 and PD-L1 on Tumor Cells Independently Predicts the Survival of Spinal Chordoma Patients.

Background: Immunotherapy only achieves efficacy in some cancer patients, and less is known about other immune checkpoint molecules in chordoma. Here, we aimed to determine the expression of PD-L1, HHLA2, B7H3, IDO-1 and Galectin-9 in spinal chordoma and evaluated their association with tumor infiltrating lymphocytes (TILs), clinicopathological characteristics and survival of patients. Methods: Using multiplexed quantitative immunofluorescence (QIF), we simultaneously measured the levels of five different immune checkpoint molecules and major TIL subsets in 92 human spinal chordoma samples. Results: Tumor HHLA2 and PD-L1 were positive in 80.0% and 86.0% of cases, respectively. However, B7H3, IDO-1 and Galectin-9 positivity on tumor cells were only seen in 21.0% of cases, despite all showing predominantly stromal expression. Coexpression of these QIF markers in the tumor compartment was scarcely detected except for PD-L1 and HHLA2, which was observed in 69.6% of cases. While tumoral HHLA2 and stromal B7H3 expressions were associated with an aggressive tumor phenotype, suppressive immune response (specifically including elevated PD-1+ TILs level and decreased CD8+ TIL density) and poor prognosis, stromal levels of PD-L1 and Galectin-9 predicted the opposite outcomes. Importantly, HHLA2 and PD-L1 coexpression on tumor cells independently predicted both worse local recurrence-free survival and overall survival. Conclusion: These data provide a better understanding of the immunosuppressive mechanism in chordoma and may be useful for the development of combination or novel immunotherapy approaches aiming to improve therapeutic efficacy and survival.

Does Prostate-Specific Membrane Antigen Avidity of Vertebral Hemangioma Change?

ABSTRACT: Vertebral hemangiomas are the most common benign tumors of the spine and mostly occur in the thoracic spine. Mostly they are detected incidentally during imaging studies for other reasons. We present the case of vertebral hemangioma that showed prostate-specific membrane antigen uptake in the second 68Ga-prostate-specific membrane antigen PET/CT, whereas no uptake was observed in the initial study.

Solitary vertebral metastatic glioblastoma in the absence of primary brain tumor relapse: a case report and literature review.

BACKGROUND: Metastatic glioblastoma presenting as a solitary osteolytic cervical vertebral mass without primary brain tumor relapse is extremely rare with only 1 reported case in the literature. Because of its rarity, it can be easily overlooked and misdiagnosed, posing a diagnostic dilemma. CASE PRESENTATION: A 51-year-old man with right temporal glioblastoma was initially treated by tumor resection, radiotherapy and chemotherapy. Eighteen months after surgery, he was readmitted with complaints of neck pain for 2 weeks. Follow-up magnetic resonance imaging (MRI) and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed a solitary FDG-avid osteolytic lesion in the 4th cervical vertebral body without other abnormal FDG-uptake in the body and in the absence of local recurrence at the resection cavity. Because of the sudden worsening situation and intractable neck pain, the patient underwent tumor resection. Postoperatively, the pain was obviously reduced and the situation was improved. Interestingly, the immunohistochemical findings of glial fibrillary acidic protein (GFAP) indicated the characteristic of metastatic glioblastoma, despite that the histopathological findings of Hematoxylin & Eosin (H&E) staining was suspicious of osteoclastoma. According to the clinical history, imaging findings, pathological and immunohistochemical results, a final diagnosis of solitary vertebral metastasis from glioblastoma without central nervous system (CNS) relapse was confirmed. Then, the patient received radiotherapy on spine and adjuvant chemotherapy with temozolomide. However, he died suddenly 2 months after the tumor resection, nearly 21 months after the initial diagnosis. CONCLUSION: We emphasize that metastatic glioblastoma should be considered in the differential diagnosis of a solitary FDG-avid osteolytic vertebral mass on PET/CT. And the diagnosis of extracranial metastasis (ECM) from glioblastoma can be achieved through clinical history, imaging findings, pathological examination, and immunohistochemical staining with GFAP.

Cytotoxic T lymphocyte antigen-4 (CTLA-4) expression in chordoma and tumor-infiltrating lymphocytes (TILs) predicts prognosis of spinal chordoma.

PURPOSE: Chordoma is a rare tumor of the skeletal system that is characterized by a high recurrence rate and treatment resistance. Given the common finding of immune dysregulation in chordoma, immunotherapy has emerged as potential treatment option. As an important immune checkpoint regulator, we evaluated cytotoxic T-lymphocyte antigen-4 (CTLA-4) expression and its prognostic significance for patients with chordoma of the spine. METHODS: CTLA-4 expression was analyzed immunohistochemically in 32 chordoma tissues and 14 nucleus pulposus tissues to examine the specificity of CTLA-4 expression in chordoma. Univariate log-rank analysis was used to evaluate the association of CTLA-4 expression in tumor cells and tumor-infiltrating lymphocytes (TILs) with survival. Cox multivariate analysis was used to identify independent factors of survival. RESULTS: Positive CTLA-4 expression was observed in all of the TILs and tumor cell cytoplasm, and partial in the membrane or in both the membrane and nucleus, with a markedly higher positivity rate than that observed in normal nucleus tissues. Higher CTLA-4 expression in the tumor but not in TILs was significantly associated with shorter continuous disease-free survival (CDFS) and overall survival (OS). CTLA-4 expression in tumor cells and TILs were independent predictors for CDFS, whereas only tumor cell expression was a significant predictor of OS. Furthermore, the combination of CTLA-4 expression in the tumor and TILs had higher prognostic value. CONCLUSIONS: Targeting CTLA-4 may be a potential novel therapeutic strategy for chordoma patients.

The one-in-all diagnostic value of 99mTc-MDP bone scan combining with single-photon emission tomography (SPECT)/CT imaging in spinal osteoblastoma.

BACKGROUND: Osteoblastoma (OB) is an intermediate lesion, which makes the accurate preoperative diagnosis very important. 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and SPECT/CT imaging were evaluated for their diagnostic value in spinal OB. METHODS: This study was a retrospective analysis of patients with spinal OB lesions confirmed by pathology and diagnosed with bone scan and SPECT/CT for preoperative diagnosis from January 2008 to December 2018. The uptake levels of OB on planar bone scan were divided into low, medium, and high groups by visual assessment referring to the uptake of the normal rib, spine, and bladder. X-ray, CT, MRI, bone scan, and SPECT/CT imaging of the patients were analyzed for characteristics summary. RESULTS: Twenty-five patients were diagnosed for spinal OB (17 males and 8 females with a proportion of 2.1:1), and the average age was 26.8 ± 10.8 years (range 5~59). There were 8 lesions located in the cervical, 6 in the thoracic, and 11 in the lumbar vertebrae. Twenty-four lesions involved posterior elements, especially the pedicles (14/25). Symptoms were predominantly painful with a duration of 18.3 ± 13.9 months (range 0.5~60 months). The lesion size ranged from 9 to 35 mm. All the lesions were low to high uptake in the planar bone scan, and the percentages of low to high levels were 1 (4%), 8 (32%), and 16 (64%) cases. CONCLUSIONS: Spinal OB mainly involved the posterior area, and elderly patients should be considered as well. SPECT/CT combined the characteristics of bone uptake and anatomical features of bone tumors, proving its one-in-all diagnostic value for spinal OB and other osteogenic tumors.

ß adrenergic receptor modulated signaling in glioma models: promoting ß adrenergic receptor-ß arrestin scaffold-mediated activation of extracellular-regulated kinase 1/2 may prove to be a panacea in the treatment of intracranial and spinal malignancy and extra-neuraxial carcinoma.

Neoplastically transformed astrocytes express functionally active cell surface ß adrenergic receptors (ßARs). Treatment of glioma models in vitro and in vivo with ß adrenergic agonists variably amplifies or attenuates cellular proliferation. In the majority of in vivo models, ß adrenergic agonists generally reduce cellular proliferation. However, treatment with ß adrenergic agonists consistently reduces tumor cell invasive potential, angiogenesis, and metastasis. ß adrenergic agonists induced decreases of invasive potential are chiefly mediated through reductions in the expression of matrix metalloproteinases types 2 and 9. Treatment with ß adrenergic agonists also clearly reduce tumoral neoangiogenesis, which may represent a putatively useful mechanism to adjuvantly amplify the effects of bevacizumab. Bevacizumab is a monoclonal antibody targeting the vascular endothelial growth factor receptor. We may accordingly designate ßagonists to represent an enhancer of bevacizumab. The antiangiogenic effects of ß adrenergic agonists may thus effectively render an otherwise borderline effective therapy to generate significant enhancement in clinical outcomes. ß adrenergic agonists upregulate expression of the major histocompatibility class II DR alpha gene, effectively potentiating the immunogenicity of tumor cells to tumor surveillance mechanisms. Authors have also demonstrated crossmodal modulation of signaling events downstream from the ß adrenergic cell surface receptor and microtubular polymerization and depolymerization. Complex effects and desensitization mechanisms of the ß adrenergic signaling may putatively represent promising therapeutic targets. Constant stimulation of the ß adrenergic receptor induces its phosphorylation by ß adrenergic receptor kinase (ßARK), rendering it a suitable substrate for alternate binding by ß arrestins 1 or 2. The binding of a ß arrestin to ßARK phosphorylated ßAR promotes receptor mediated internalization and downregulation of cell surface receptor and contemporaneously generates a cell surface scaffold at the ßAR. The scaffold mediated activation of extracellular regulated kinase 1/2, compared with protein kinase A mediated activation, preferentially favors cytosolic retention of ERK1/2 and blunting of nuclear translocation and ensuant pro-transcriptional activity. Thus, ßAR desensitization and consequent scaffold assembly effectively retains the cytosolic homeostatic functions of ERK1/2 while inhibiting its pro-proliferative effects. We suggest these mechanisms specifically will prove quite promising in developing primary and adjuvant therapies mitigating glioma growth, angiogenesis, invasive potential, and angiogenesis. We suggest generating compounds and targeted mutations of the ß adrenergic receptor favoring ß arrestin binding and scaffold facilitated activation of ERK1/2 may hold potential promise and therapeutic benefit in adjuvantly treating most or all cancers. We hope our discussion will generate fruitful research endeavors seeking to exploit these mechanisms.

Molecular profiling of an osseous metastasis in glioblastoma during checkpoint inhibition: potential mechanisms of immune escape.

Peripheral metastases of glioblastoma (GBM) are very rare despite the ability of GBM cells to pass through the blood-brain barrier and be disseminated through the peripheral blood. Here, we describe a detailed genetic and immunological characterization of a GBM metastasis in the skeleton, which occurred during anti-PD-1 immune checkpoint therapy. We performed whole genome sequencing (WGS) and 850 K methylation profiling of the primary and recurrent intracranial GBM as well as one of the bone metastases. Copy number alterations (CNA) and mutational profiles were compared to known genomic alterations in the TCGA data base. In addition, immunophenotyping of the peripheral blood was performed. The patient who was primarily diagnosed with IDH-wildtype GBM. After the resection of the first recurrence, progressive intracranial re-growth was again detected, and chemotherapy was replaced by PD-1 checkpoint inhibition, which led to a complete intracranial remission. Two months later MR-imaging revealed multiple osseous lesions. Biopsy confirmed the GBM origin of the skeleton metastases. Immunophenotyping reflected the effective activation of a peripheral T-cell response, with, however, increase of regulatory T cells during disease progression. WGS sequencing demonstrated distinct genomic alterations of the GBM metastasis, with gains along chromosomes 3 and 9 and losses along chromosome 4, 10, and 11. Mutational analysis showed mutations in potentially immunologically relevant regions. Additionally, we correlated tumour-infiltrating lymphocyte and microglia presence to the occurrence of circulating tumour cells (CTCs) in a larger cohort and found a decreased infiltration of cytotoxic T cells in patients positive for CTCs. This study exemplifies that the tumour microenvironment may dictate the response to immune checkpoint therapy. In addition, our study highlights the fact that despite an effective control of intracranial GBM, certain tumour clones have the ability to evade the tumour-specific T-cell response and cause progression even outside of the CNS.

Survival in breast cancer patients with spine metastases: Prognostic assessment involving molecular markers.

BACKGROUND: To clarify and update the prognostic assessment for heterogeneous population of patients with breast cancer and spine metastases (SpM), using molecular markers. METHODS: The patient data used in this study was obtained from a French national multi-center database of patients treated for breast cancer with SpM between 2014 and 2017. 556 SpM cases were diagnosed. RESULTS: Median overall survival (OS) time for all patients following the SpM event was 43.9 months. First, we confirmed 3 previously known significant prognostic factors for survival of patients with SpM: young age [HR: 2.019, 95% CI 1.343-3.037; p = 0.001], good WHO status [ Status 0 HR: 2.823, 95% CI 1.231-3.345; p < 0.0001] or [ Status 1 HR: 1.956, 95% CI 0.768-2.874; p = 0.001] and no-ambulatory neurological status: Frankel A-C [HR: 0.438, 95% CI 0.248-0.772; p = 0.004]. Secondly, we determined the effect of gene mutations on survival in patients with SpM, and we identified that HER2+ cancer subtype [HR: 1.567, 95% CI 0.946-2.557; p = 0.008] was an independent predictor of longer survival, whereas basal cancer subtype [HR: 0.496, 95% CI 0.353-0.699; p < 0.0001] was associated with a poorer prognosis. Other factors including the number of SpM, surgery, extraspinal metastases, synchrone metastases, metastasis-free survival, and SpM recurrence were not identified as prognostically relevant to survival. CONCLUSION: Survival and our ability to estimate it in breast cancer patients with SpM has improved significantly. Therefore, SpM prognostic scoring algorithms should be updated and incorporate genotypic data on subtypes to make treatment more adaptive.

Intracranial ependymomas: molecular insights and translation to treatment.

Ependymomas are primary central nervous system tumors (CNS), arising within the posterior fossa and supratentorial regions of the brain, and in the spine. Over the last decade, research has resulted in substantial insights into the molecular characteristics of ependymomas, and significant advances have been made in the establishment of a molecular classification system. Ependymomas both within and between the three CNS regions in which they arise, have been shown to contain distinct genetic, epigenetic and cytogenic aberrations, with at least three molecularly distinct subgroups identified within each region. However, these advances in molecular characterization have yet to be translated into clinical practice, with the standard treatment for ependymoma patients largely unchanged. This review summarizes the advances made in the molecular characterization of intracranial ependymomas, outlines the progress made in establishing preclinical models and proposes strategies for moving toward subgroup-specific preclinical investigations and treatment.

Pharmacokinetic Analysis of [18F]FAZA Dynamic PET Imaging Acquisitions for Highlighting Sacrum Tumor Profiles.

A patient enrolled in a clinical trial (NCT02802969) with suspicion of chordoma underwent an [F]FAZA PET/CT, a radiolabeled nitroimidazole analog of hypoxia PET imaging. The patient's images showed a different tumor profile compared to those observed in other hypoxic or nonhypoxic chordoma patients. The motivation for using [F]FAZA pharmacokinetic imaging was to compare this profile with histologically confirmed cases of chordoma. Through visual imaging and quantification of blood and tumor time-activity curves, we excluded the hypothesis that it was a chordoma, diagnosing a paraganglioma.

Maximum standardized uptake value from quantitative bone single-photon emission computed tomography/computed tomography in differentiating metastatic and degenerative joint disease of the spine in prostate cancer patients.

OBJECTIVE: Qualitative interpretation in bone scan is often complicated by the presence of degenerative joint disease (DJD), especially in the elderly patient. The aim of this study is to compare objectively 99mTc-MDP tracer uptake between DJD and osseous metastases of the spine using semi-quantitative assessment with SPECT SUV. METHODS: Bone scan with SPECT/CT using 99mTc-MDP was performed in 34 patients diagnosed with prostate carcinoma. SPECT/CT was performed based on our institutional standard guidelines. SUVmax based on body weight in 238 normal vertebrae visualized on SPECT/CT was quantified as baseline. A total of 211 lesions in the spine were identified on bone scan. Lesions were characterized into DJD or bone metastases based on its morphology on low-dose CT. Semi-quantitative evaluation using SUVmax was then performed on 89 DJD and 122 metastatic bone lesions. As most of the bone lesions were small in volume, the effect of partial volume effect (PVE) on SUVmax was also assessed. The corrected SUVmax values were obtained based on the recovery coefficient (RC) method. RESULTS: The mean SUVmax for normal vertebrae was 7.08 ± 1.97, 12.59 ± 9.01 for DJD and 36.64 ± 24.84 for bone metastases. The SUVmax of bone metastases was significantly greater than DJD (p value < 0.05). To assess for diagnostic accuracy, receiver operating characteristic (ROC) curve was performed. The area under the curve (AUC) was found to be fairly high at 0.874 (95% CI 0.826-0.921). The cutoff SUVmax value ≥ 20 gave a sensitivity of 73.8% and specificity of 85.4% in differentiating bone metastases from DJD. The corrected SUVmax for both DJD and bone metastases was smaller with a mean of 6.82 ± 6.02 and 24.77 ± 20.61, respectively. The cutoff SUVmax value was also lower with a value of 10, which gave a sensitivity of 73.8% and specificity of 86.5%. CONCLUSION: SPECT SUVmax was significantly higher in bone metastases than DJD. Semi-quantitative assessment with SUVmax can complement qualitative analysis. A cutoff SUVmax of ≥ 20 can be used to differentiate bone metastases from DJD. Partial volume effect should be taken into consideration in the quantification of small lesion size.

Phosphoproteomic profiling of oxycodone­treated spinal cord of rats with cancer­induced bone pain.

Treatment of cancer­induced bone pain (CIBP) is challenging in clinical settings. Oxycodone (OXY) is used to treat CIBP; however, a lack of understanding of the mechanisms underlying CIBP limits the application of OXY. In the present study, all rats were randomly divided into three groups: The sham group, the CIBP group, and the OXY group. Then, a rat model of CIBP was established by inoculation of Walker 256 tumor cells from rat tibia. Phosphoproteomic profiling of the OXY­treated spinal dorsal cords of rats with CIBP was performed, and 1,679 phosphorylated proteins were identified, of which 160 proteins were significantly different between the CIBP and sham groups, and 113 proteins were significantly different between the CIBP and OXY groups. Gene Ontology analysis revealed that these proteins mainly clustered as synaptic­associated cellular components; among these, disks large homolog 3 expression was markedly increased in rats with CIBP and was reversed by OXY treatment. Subsequent domain analysis of the differential proteins revealed several significant synaptic­associated domains. In conclusion, synaptic­associated cellular components may be critical in OXY­induced analgesia in rats with CIBP.

Combined intravoxel incoherent motion diffusion-weighted MR imaging and magnetic resonance spectroscopy in differentiation between osteoporotic and metastatic vertebral compression fractures.

PURPOSE: Our purpose was to combine intravoxel incoherent motion diffusion-weighted MR imaging (IVIM-DWI) and magnetic resonance spectroscopy (MRS) to differentiate osteoporotic fractures from osteolytic metastatic vertebral compression fractures (VCFs). METHODS: A total of 70 patients with VCFs were included and divided into two groups, according to their causes of fractures based on pathological findings or clinical follow-up. All patients underwent conventional sagittal T1WI, T2WI, STIR, IVIM-DWI, and single-voxel MRS. The diffusion coefficient (D), pseudo diffusion (D*), and perfusion fraction (f) parameters from IVIM-DWI and the lipid water ratio (LWR) and fat fraction (FF) parameters from MRS were obtained and compared among groups. Furthermore, the diagnostic performance of MRS, IVIM-DWI, and IVIM-DWI combined with MRS for differentiation between osteoporotic and osteolytic metastatic VCFs was assessed by using receiver operating characteristic (ROC) curve analysis. RESULTS: Compared with the osteoporotic group, the metastatic group had significantly lower values for f, D, and FF, but higher D* (all P < 0.05). The area under the receiver operating characteristic (ROC) curve of MRS, IVIM-DWI, and IVIM-DWI combined with MRS were 0.73, 0.88, and 0.94, respectively. Among these, the IVIM-DWI combined with MRS showed the highest sensitivity, specificity, and accuracy, which are 90.63% (29/32), 97.37 % (37/38), and 94.29% (66/70), respectively. CONCLUSIONS: IVIM-DWI combined with MRS can be more accurate and efficient for differentiation between osteoporotic and osteolytic metastatic VCFs than single MRS or IVIM-DWI.

Detecting the long non­coding RNA signature related to spinal cord ependymal tumor subtype using a genome­wide methylome analysis approach.

Ependymoma is a type of intramedullary tumor that tends to occur in the adult spinal cord. Ependymoma affects the nervous system and has significant impacts on the quality of life, and it may lead to mortality. Previous studies have performed molecular classification of spinal cord ependymal tumors at the DNA methylation level. However, the DNA methylation status of non­coding regions in spinal cord ependymal tumors remains unclear. In the present study, a genome­wide methylome method was used to characterize the DNA methylation landscape of long non­coding RNAs (lncRNAs) in spinal cord ependymal tumor samples. The present study identified lncRNA signatures associated with tumor subtypes based on the methylation status of lncRNA promoters. The present results suggested that the identified lncRNA signatures were associated with cancer­ or nervous system­related protein­coding genes. The majority of the identified lncRNAs was hypomethylated, and may have a role in spinal cord development. The present findings suggested that detection of tumor subtype­specific lncRNAs may facilitate the identification of novel diagnostic and therapeutic strategies to treat patients with spinal cord ependymal tumor.