A Novel Rat Model of Venous Hypertensive Myelopathy Produced by Arteriovenous Bypass Plus Venous Stenosis

BACKGROUND AND OBJECTIVES

Venous hypertensive myelopathy (VHM), mainly induced by the spinal dural arteriovenous fistula, is a congestive spinal cord injury that currently has no appropriate animal model available in preclinical research.

METHODS

Sprague Dawley rats (280-320 g) were used. The rats were divided into 3 groups: (1) Group 1, which underwent renal artery-dorsal spinal venous bypass (AVB group); (2) Group 2, which underwent renal artery-dorsal spinal venous bypass and drainage vein stenosis (AVB/VS group); and (3) Control group, with T13 dorsal vein ligation. The success of the model was assessed using Doppler ultrasound and 7.0-T magnetic resonance imaging. Transmission electron microscopy, histochemistry, proteomics, and western blot analysis were used to evaluate ultrastructural, pathological, and molecular features in the spinal cord and cerebrospinal fluid (CSF).

RESULTS

The success rate of the arteriovenous bypass was 100% at 5 days and 83% at 2 weeks. The locomotor assessment showed decreased lower extremity strength in the AVB/VS group (P = .0067), whereas unremarkable changes were found in the AVB and Control groups. Histochemical staining suggested a 2-fold expansion of the dorsal spinal vein in the AVB/VS group, which was lower than that in the AVB group (P < .05); however, the former displayed greater myelin and neuronal damage (P < .05) and slight dilatation of the central canal (P > .05). Proteomics analysis revealed that the complement and coagulation cascade pathways were upregulated in the CSF of AVB/VS rats, whereas the C3 level was elevated both in the CSF and bilateral spinal cord. Furthermore, overexpression of C3, ITGB2, and CD9 in the spinal cord was confirmed by immunoblotting.

CONCLUSION

These findings suggest that the AVB/VS model can effectively mimic the clinical and molecular characteristics of VHM. Furthermore, they suggest that impaired deep intramedullary venous drainage is the key reason for the VHM.

The subcommissural organ regulates brain development via secreted peptides

The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. To explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3, and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely thymosin beta 4, thymosin beta 10, and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.

Isolated sinus dural arteriovenous fistulas: a single-center experience in 44 patients

BACKGROUND

Isolated sinus dural arteriovenous fistulas (DAVFs) constitute a rare and distinctive subtype of DAVF, typically found in small case numbers or case reports. The optimal treatment for this DAVF type remains unclear.

OBJECTIVE

This study aims to further detail the treatment outcomes of isolated sinus DAVFs in a sizable cohort from a single center.

METHODS

A retrospective study was undertaken on a consecutive series of patients with isolated sinus DAVFs treated at a single institution from 2002 to 2022. The article delineates the clinical presentation, angiographic features, treatment strategy, clinical and angiographic outcomes, and complications.

RESULTS

The cohort consisted of 31 males and 13 females, with an average age of 52.0 ± 15.5 years (range, 16-83). The success rate for trans-arterial embolization (TAE) was 97.3% (36/37). Transvenous embolization (TVE) with the reopening technique was successful in 3 of 4 patients (75.0%). Two open burr-hole TVE cases (66.7%, 2/3) and one surgery (100%) resulted in immediate complete closure of the fistula. Immediate complete occlusion was achieved in 93.2% (41/44) of cases. There was one major complication (2.3%, 1/44) and two fistulas recurred (9.5%, 2/21).

CONCLUSIONS

The majority of isolated sinus DAVFs can be effectively treated with TAE using Onyx. TVE and surgery serve as alternative techniques when arterial access is deemed inappropriate or when complete occlusion cannot be attained with TAE. Complete embolization of isolated sinus DAVFs by TAE can typically be achieved without delay.

Middle cranial fossa non-cavernous sinus dural arteriovenous fistulas: 20 years of experience

Non-cavernous sinus (CS) dural arteriovenous fistulas (DAVFs) involving the sphenoid bone are rare entities that are easily confused with one another due to the complex structure and high variability of the venous system around the middle cranial fossa. We present a large retrospective study on middle cranial fossa non-CS DAVFs and review the literature on DAVF treatment in this location as well as relative anatomy. 15 patients had DAVFs involving the lesser sphenoid wing and 11 patients had DAVFs involving the greater sphenoid wing. Six patients presented with intracranial hemorrhage or subarachnoid hemorrhage (23.1%, 6/26). The most common symptoms were eye symptoms (38.5%, 10/26). Nineteen patients were treated with trans-arterial embolization (TAE) using liquid embolic agents and two patients were treated with transvenous embolization (TVE) using Onyx or in combination with coils. Surgical disconnection of the drainage veins was performed in five patients, with three cases experiencing unsuccessful TAE. Anatomic cure was achieved in 92.3% of the patients (24/26). Twelve patients had DSA and clinical follow-up from 3 to 27 months. There was one recurrence (8.3%) of the fistula in the patient two months after the initial complete occlusion. The majority of patients can be cured endovascularly. Laterocavernous sinus DAVFs may not be embolized by transvenous approach via the cavernous sinus because there is often no connection between them in most patients. A small percentage of patients may require surgical ligation to be cured.

Clinical and prognostic features of venous hypertensive myelopathy from craniocervical arteriovenous fistulas: a retrospective cohort study

OBJECTIVE

Current knowledge about venous hypertensive myelopathy (VHM) is incomplete. This study was performed with the aim of clarifying the clinical features and outcomes of craniocervical VHM.

METHODS

This retrospective, single-center cohort study included 65 patients with craniocervical junction arteriovenous fistulas resulting in VHM treated in Xuanwu Hospital from January 1, 2002, to December 30, 2020. All patients underwent microsurgery or endovascular treatment. The primary outcome was neurological function assessment using the Japanese Orthopaedic Association (JOA) scale, modified Aminoff-Logue Scale (mALS), and Venous Hypertensive Myelopathy Scale (VHMS). The secondary outcomes were recurrences and postoperative adverse events. Pearson linear regression and receiver operating characteristic curves were used to evaluate the relationships among the three scales. Kaplan-Meier and multivariate logistic regression analyses were performed to predict outcomes.

RESULTS

The mean patient age was 57.4 ± 11.4 years, and 88% of patients were male. The 1-year follow-up rate was 83.1%, and the 5-year follow-up rate was 50.8%. The VHMS was correlated with the JOA (R2 = 0.6722) and mALS (R2 = 0.7399) and increased the assessment accuracy by approximately 20% when compared with the other two scales. Overall, 25.9% of patients experienced delayed neurological decline beyond the 1-year follow-up. Further logistic regression suggested that age > 65 years was an independent predictor (OR 7.831, 95% CI 1.090-56.266; p = 0.041). Embolic recanalization and new bilateral symmetry feeders were the major reasons for recurrence. Recurrence increased the risk of adverse events after the second surgery (OR 20.455, 95% CI 1.170-357.320; p = 0.039).

CONCLUSIONS

CCJ AVFs resulting in VHM are a rare but deadly complication, and providers should be cautious of age-related delayed neurological decline and strive for a one-time anatomical cure.

Somatic variants of MAP3K3 are sufficient to cause cerebral and spinal cord cavernous malformations

Cerebral cavernous malformations (CCMs) and spinal cord cavernous malformations (SCCMs) are common vascular abnormalities of the CNS that can lead to seizure, haemorrhage and other neurological deficits. Approximately 85% of patients present with sporadic (versus congenital) CCMs. Somatic mutations in MAP3K3 and PIK3CA were recently reported in patients with sporadic CCM, yet it remains unknown whether MAP3K3 mutation is sufficient to induce CCMs. Here we analysed whole-exome sequencing data for patients with CCM and found that ∼40% of them have a single, specific MAP3K3 mutation [c.1323C>G (p.Ile441Met)] but not any other known mutations in CCM-related genes. We developed a mouse model of CCM with MAP3K3I441M uniquely expressed in the endothelium of the CNS. We detected pathological phenotypes similar to those found in patients with MAP3K3I441M. The combination of in vivo imaging and genetic labelling revealed that CCMs were initiated with endothelial expansion followed by disruption of the blood-brain barrier. Experiments with our MAP3K3I441M mouse model demonstrated that CCM can be alleviated by treatment with rapamycin, the mTOR inhibitor. CCM pathogenesis has usually been attributed to acquisition of two or three distinct genetic mutations involving the genes CCM1/2/3 and/or PIK3CA. However, our results demonstrate that a single genetic hit is sufficient to cause CCMs.

A retrospective study of 78 adult tentorial middle line region dural arteriovenous fistulae

OBJECTIVE

Dural arteriovenous fistulae (DAVF) in the tentorial middle line region are uncommon with specific features and more cognitive disorders than any other region. The purpose of this study is to present clinical characteristics and our experience with endovascular treatment in this specific region.

METHODS

During a 20-year period, 94.9% of patients (74/78) underwent endovascular treatment (36 in galenic, 48.6%) (12 in straight sinus, 16.2%) (26 in torcular, 35.1%). There were 63 males and 15 females with mean age of 50 (50 ± 12) years in total of 78 patients. The clinical presentation, angiographic features, treatment strategy, and clinical outcomes were recorded.

RESULTS

Transarterial embolization (TAE) was performed in 89.2% of the 74 patients (66/74), transvenous embolization alone in one patient and mixed approach in seven. Complete obliteration of the fistulas was obtained in 87.5% of the patients (64/74). 71 patients (mean, 56 months) had phone, outpatient, or admission follow-up. The digital subtraction angiography (DSA) follow-up period (25/78, 32.1%) was 13.8 (6-21) months. Two of them (2/25, 8%) had fistula recurrences after complete embolization and were embolized again. The phone follow-up period (70/78, 89.7%) was 76.6 (40-92.3) months. Pre-embolization and post-embolization mRS ≥ 2 were in 44 patients (44/78) and 15 (15/71) patients, respectively. DAVF with internal cerebral vein drainage (OR 6.514, 95% Cl 1.201-35.317) and intracranial hemorrhage (OR 17.034, 95% Cl 1.122-258.612) during TAE were the risk factors for predicting poor outcomes (followed up mRS ≥ 2).

CONCLUSIONS

TAE is the first-line treatment for tentorial middle line region DAVF. When pial feeders' obliteration is difficult to achieve, it should not be forced due to the poor outcomes after intracranial hemorrhage. The cognitive disorders caused by this region were not reversible as reported. It is imperative to enhance the care provided to these patients with cognitive disorders.

Adult dural arteriovenous fistulas in Galen region: More to be rediscovered

BACKGROUND

Dural arteriovenous fistulas (DAVFs) in the Galen region are the most deeply located and most complex type of dural arteriovenous fistulas. However, cases of DAVFs in this region have not been well described. Thus, we aimed to summarize the characteristics of Galenic DAVFs involving clinical symptoms, anatomical architecture, and drainage patterns, providing experientially therapeutic strategies for these lesions based on our 20 years of clinical experience.

METHODS

We retrospectively examined 31 patients with Galenic DAVFs between January 2000 and June 2021. A comprehensive analysis was carried out based on the symptoms, imaging features, feeding arteries, draining veins, number and location of the fistulas, choice of treatment methods, and prognosis assessment.

RESULTS

Twenty-nine patients received endovascular embolization, and no perioperative deaths occurred. A transarterial approach was performed in 27 patients, and a combined transarterial and transvenous approach in one. And in one case, access was established by surgical drilling and embolization was done via the venous route. Twenty-four cases were completely obliterated after first embolization, and another five cases received a second period treatment. Only one patient developed cognitive dysfunction after embolization, and the outcomes of the remaining patients were improved at long-term follow-up.

CONCLUSION

The understanding of symptoms of non-hemorrhagic neurological deficits in DAVF needs to be further clarified. Lesions with pial feeders may be considered first when determining surgical orders. Multi-approach and multi-stage embolization would be safe and effective. Excessive embolization and deep-vein system obstruction should be avoided. Approach creation by surgery would be an innovative interventional therapy.

New insight into DAVF pathology—Clues from meningeal immunity

In recent years, with the current access in techniques, studies have significantly advanced the knowledge on meningeal immunity, revealing that the central nervous system (CNS) border acts as an immune landscape. The latest concept of meningeal immune system is a tertiary structure, which is a comprehensive overview of the meningeal immune system from macro to micro. We comprehensively reviewed recent advances in meningeal immunity, particularly the new understanding of the dural sinus and meningeal lymphatics. Moreover, based on the clues from the meningeal immunity, new insights were proposed into the dural arteriovenous fistula (DAVF) pathology, aiming to provide novel ideas for DAVF understanding.

Cerebral Cavernous Malformation: Immune and Inflammatory Perspectives

Cerebral cavernous malformation (CCM) is a type of vascular anomaly that arises due to the dyshomeostasis of brain capillary networks. In the past two decades, many advances have been made in this research field. Notably, as a more reasonable current view, the CCM lesions should be attributed to the results of a great number of additional events related to the homeostasis disorder of the endothelial cell. Indeed, one of the most fascinating concerns in the research field is the inflammatory perturbation in the immune microenvironment, which would affect the disease progression as well as the patients’ outcomes. In this work, we focused on this topic, and underlined the immune-related factors’ contribution to the CCM pathologic progression.

Potential biomarkers of spinal dural arteriovenous fistula: C4BPA and C1QA

Background and purpose

A major challenge in spinal dural arteriovenous fistula (SDAVF) is timely diagnosis, but no specific predictive biomarkers are known.

Methods

In the discovery cohort (case, n = 8 vs. control, n = 8), we used cerebrospinal fluid (CSF) and paired plasma samples to identify differentially expressed proteins by label-free quantitative proteomics. Further bioinformatics enrichment analyses were performed to screen target proteins. Finally, it was validated by ELISA in two of the new cohorts (case, n = 17 vs. control, n = 9), and univariate analysis, simple linear regression, and receiver operator characteristic (ROC) curve analysis were performed to evaluate the diagnostic potential.

Results

In the discovery cohort, the most overexpressed proteins were APOB and C4BPA in CSF samples of patients. The GO/KEGG enrichment analysis indicated that the upregulated proteins were mainly involved in the acute inflammatory response and complement activation. Hub-gene analysis revealed that APP might be the key protein in the molecular interaction network. In the validation cohort, C4BPA and C1QA were significantly overexpressed in the CSF of patients, averaging 3046.9 ng/ml and 2167.2 ng/ml, respectively. Simple linear regression demonstrated that levels of C1QA and C4 were positively correlated with total protein in CSF (R² = 0.8021, p = 0.0005; R² = 0.7447, p = 0.0013). The areas under the ROC curves of C4BPA and C1QA were 0.86 and 1.00, respectively.

Conclusions

This study was the first to identify C4BPA and C1QA as potential biomarkers for the diagnosis of SDAVF and revealed that complement pathway activation might be one of the molecular mechanisms for venous hypertension myelopathy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02522-x.

[Predictive value of impedance of leadless pacemaker during implantation on trend changes of pacing threshold]

Objective: To explore the predictive value of the impedance measured during leadless pacemaker Micra implantation on the trend of changes of pacing threshold post implantation. Methods: This is a retrospective cross-sectional study. Patients who received implantation of leadless pacemaker Micra at the Second Xiangya Hospital of Central South University from December 2019 to August 2020 were enrolled. The clinical data and the intraoperative electrical parameters during leadless pacemaker implantation were collected. The impedance and pacing threshold data were analyzed at three time points: immediate release, 5-10 min after release, and after traction test. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to analyze the value of the impedance at immediate release on predicting the trend of changes of pacing threshold post implantation. Results: A total of 21 patients (mean age: (72.2±12.5) years, 12 males) were included. The impedance of 21 patients was (798.1±35.3) Ω immediately after implantation, (800.9±35.6) Ω after 5-10 minutes of release, and (883.6±31.7) Ω after traction test. Impedance was similar between the three time points (P>0.05). The threshold was (0.97±0.11) V/0.24 ms immediately after implantation, (0.95±0.12) V/0.24 ms at 5-10 min after the release, and (0.59±0.06) V/0.24 ms after the traction test. The threshold was significantly lower after the traction test than that immediately after release (P=0.003) and than that at 5-10 minutes after release (P=0.008), suggesting a decreased tendency of the threshold over time. According to the analysis of the ROC curve, the immediate impedance after the release ≥680 Ω could predict the ideal pacing threshold after the traction test (AUC=0.989, 95%CI 0.702-0.964, P<0.001), the prediction sensitivity was 87%, and the specificity was 100%. The pacing threshold would be not ideal with the immediate impedance ≤ 520 Ω (95%CI 0.893-1.000, P<0.001), the sensitivity was 100%, and the specificity was 80%. Conclusions: The impedance immediately after the release has predictive value for the changing trend of threshold post leadless pacemaker Micra implantation. Impedance ≥680 Ω immediately after release is often related with ideal pacing threshold after the traction test. In contrast, the impedance ≤ 520 Ω pacing is often related with unsatisfactory threshold after the traction test, therefore, it is recommended to find a new pacing site to achieve the impedance ≥680 Ω immediately after release during leadless pacemaker Micra implantation.

Spatial-Spectral Density Peaks-Based Discriminant Analysis for Membranous Nephropathy Classification Using Microscopic Hyperspectral Images

The traditional differential diagnosis of membranous nephropathy (MN) mainly relies on clinical symptoms, serological examination and optical renal biopsy. However, there is a probability of false positives in the optical inspection results, and it is unable to detect the change of biochemical components, which poses an obstacle to pathogenic mechanism analysis. Microscopic hyperspectral imaging can reveal detailed component information of immune complexes, but the high dimensionality of microscopic hyperspectral image brings difficulties and challenges to image processing and disease diagnosis. In this paper, a novel classification framework, including spatial-spectral density peaks-based discriminant analysis (SSDP), is proposed for intelligent diagnosis of MN using a microscopic hyperspectral pathological dataset. SSDP constructs a set of graphs describing intrinsic structure of MHSI in both spatial and spectral domains by employing density peak clustering. In the process of graph embedding, low-dimensional features with important diagnostic information in the immune complex are obtained by compacting the spatial-spectral local intra-class pixels while separating the spectral inter-class pixels. For the MN recognition task, a support vector machine (SVM) is used to classify pixels in the low-dimensional space. Experimental validation data employ two types of MN that are difficult to distinguish with optical microscope, including primary MN and hepatitis B virus-associated MN. Experimental results show that the proposed SSDP achieves a sensitivity of 99.36%, which has potential clinical value for automatic diagnosis of MN.

Deep learning-based framework for the distinction of membranous nephropathy: a new approach through hyperspectral imagery

Background

Common subtypes seen in Chinese patients with membranous nephropathy (MN) include idiopathic membranous nephropathy (IMN) and hepatitis B virus-related membranous nephropathy (HBV-MN). However, the morphologic differences are not visible under the light microscope in certain renal biopsy tissues.

Methods

We propose here a deep learning-based framework for processing hyperspectral images of renal biopsy tissue to define the difference between IMN and HBV-MN based on the component of their immune complex deposition.

Results

The proposed framework can achieve an overall accuracy of 95.04% in classification, which also leads to better performance than support vector machine (SVM)-based algorithms.

Conclusion

IMN and HBV-MN can be correctly separated via the deep learning framework using hyperspectral imagery. Our results suggest the potential of the deep learning algorithm as a new method to aid in the diagnosis of MN.

Membranous nephropathy classification using microscopic hyperspectral imaging and tensor patch-based discriminative linear regression

Optical kidney biopsy, serological examination, and clinical symptoms are the main methods for membranous nephropathy (MN) diagnosis. However, false positives and undetectable biochemical components in the results of optical inspections lead to unsatisfactory diagnostic sensitivity and pose obstacles to pathogenic mechanism analysis. In order to reveal detailed component information of immune complexes of MN, microscopic hyperspectral imaging technology is employed to establish a hyperspectral database of 68 patients with two types of MN. Based on the characteristic of the medical HSI, a novel framework of tensor patch-based discriminative linear regression (TDLR) is proposed for MN classification. Experimental results show that the classification accuracy of the proposed model for MN identification is 98.77%. The combination of tensor-based classifiers and hyperspectral data analysis provides new ideas for the research of kidney pathology, which has potential clinical value for the automatic diagnosis of MN.

AGAP2-AS1 May Promote the Occurrence and Development of Glioblastoma by Sponging miR-9-5p: Evidence From a ceRNA Network

Glioblastoma (GBM), the primary malignant brain tumor, is typically associated with a poor prognosis and poor quality of life, mainly due to the lack of early diagnostic biomarkers and therapeutic targets. However, gene sequencing technologies and bioinformatics analysis are currently being actively utilized to explore potential targets for the diagnosis and management of malignancy. Herein, based on a variety of bioinformatics tools for the reverse prediction of target genes associated with the prognosis of GBM, a ceRNA network of AGAP2-AS1-miR-9-5p-MMP2/MMP9 was constructed, and a potential therapeutic target for GBM was identified. Enrichment analysis predicted that the ceRNA regulatory network participates in the processes of cell proliferation, differentiation, and migration.

ceRNA Network Analysis Shows That lncRNA CRNDE Promotes Progression of Glioblastoma Through Sponge mir-9-5p

Glioblastoma accounts for 45.2% of central nervous system tumors. Despite the availability of multiple treatments (e.g., surgery, radiotherapy, chemotherapy, biological therapy, immunotherapy, and electric field therapy), glioblastoma has a poor prognosis, with a 5-year survival rate of approximately 5%. The pathogenesis and prognostic markers of this cancer are currently unclear. To this end, this study aimed to explore the pathogenesis of glioblastoma and identify potential prognostic markers. We used data from the GEO and TCGA databases and identified five genes (ITGA5, MMP9, PTPRN, PTX3, and STX1A) that could affect the survival rate of glioblastoma patients and that were differentially expressed between glioblastoma patients and non-tumors groups. Based on a variety of bioinformatics tools for reverse prediction of target genes associated with the prognosis of GBM, a ceRNA network of messenger RNA (STX1A, PTX3, MMP9)-microRNA (miR-9-5p)-long non-coding RNA (CRNDE) was constructed. Finally, we identified five potential therapeutic drugs (bacitracin, hecogenin, clemizole, chrysin, and gibberellic acid) that may be effective treatments for glioblastoma.

Irisin Contributes to Neuroprotection by Promoting Mitochondrial Biogenesis After Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating form of stroke, which poses a series of intractable challenges to clinical practice. Imbalance of mitochondrial homeostasis has been thought to be the crucial pathomechanism in early brain injury (EBI) cascade after SAH. Irisin, a protein related to metabolism and mitochondrial homeostasis, has been reported to play pivotal roles in post-stroke neuroprotection. However, whether this myokine can exert neuroprotection effects after SAH remains unknown. In the present study, we explored the protective effects of irisin and the underlying mechanisms related to mitochondrial biogenesis in a SAH animal model. Endovascular perforation was used to induce SAH, and recombinant irisin was administered intracerebroventricularly. Neurobehavioral assessments, TdT-UTP nick end labeling (TUNEL) staining, dihydroethidium (DHE) staining, immunofluorescence, western blot, and transmission electron microscopy (TEM) were performed for post-SAH assessments. We demonstrated that irisin treatment improved neurobehavioral scores, reduced neuronal apoptosis, and alleviated oxidative stress in EBI after SAH. More importantly, the administration of exogenous irisin conserved the mitochondrial morphology and promoted mitochondrial biogenesis. The protective effects of irisin were partially reversed by the mitochondrial uncoupling protein-2 (UCP-2) inhibitor. Taken together, irisin may have neuroprotective effects against SAH via improving the mitochondrial biogenesis, at least in part, through UCP-2 related targets.

High gene expression levels of VEGFA and CXCL8 in the peritumoral brain zone are associated with the recurrence of glioblastoma: A bioinformatics analysis

The present study aimed to identify differentially regulated genes between the peritumoral brain zone (PBZ) and tumor core (TC) of glioblastoma (GBM), to elucidate the underlying molecular mechanisms and provide a target for the treatment of tumors. The GSE13276 and GSE116520 datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) for the PBZ and TC were obtained using the GEO2R tool. The bioinformatics and evolutionary genomics online tool Venn was used to identify common DEGs between the two datasets. The Database for Annotation, Visualization, and Integrated Discovery online tool was used to analyze enriched pathways of the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The Search Tool for the Retrieval of Interacting Genes/Proteins online tool was used to construct a protein-protein interaction (PPI) network of DEGs. Hub genes were identified using Cytohubba, a plug-in for Cytoscape. The Gene Expression Profiling Interactive Analysis (GEPIA) database was utilized to perform survival analysis. In total, 75 DEGs, including 12 upregulated and 63 downregulated genes, were identified. In the GO term analysis, these DEGs were mainly enriched in ‘regulation of angiogenesis’ and ‘central nervous system development’. Furthermore, in the KEGG pathway analysis, the DEGs were mainly enriched in ‘bladder cancer’ and ‘endocytosis’. When filtering the results of the PPI network analysis using Cytohubba, a total of 10 hub genes, including proteolipid protein 1, myelin associated oligodendrocyte basic protein, contactin 2, myelin oligodendrocyte glycoprotein, myelin basic protein, myelin associated glycoprotein, SRY-box transcription factor 10, C-X-C motif chemokine ligand 8 (CXCL8), vascular endothelial growth factor A (VEGFA) and plasmolipin, were identified. These hub genes were further subjected to GO term and KEGG pathway analysis, and were revealed to be enriched in ‘central nervous system development’, ‘bladder cancer’ and ‘rheumatoid arthritis’. These hub genes were used to perform survival analysis using the GEPIA database, and it was determined that VEGFA and CXCL8 were significantly associated with a reduction in the overall survival of patients with GBM. In conclusion, the results suggest that the recurrence of GBM is associated with high gene expression levels VEGFA and CXCL8, and the development of the central nervous system.

P1889Quantitative global proteomics and lysine acetylome analysis of changes in left atrial appendage tissue from valvular heart disease patients with atrial fibrillation

Background

Previous studies have shown that acetylation plays a critical role in regulating the progress of cardiovascular diseases by acetylated histone and non-histones protein. However, the global lysine acetylome during atrial fibrillation (AF) were not fully understood.

Purpose

The aim of the present study was to identify the underlying mechanisms of AF via profiling of the quantitative changes of global proteomics and lysine acetylome in the left atrial appendage (LAA) tissues from valvular heart disease patients with AF.

Methods

This study obtained LAA specimens from patients undergoing cardiac surgery for severe valvular heart disease. The LAA specimens were obtained from both 9 patients with AF and with sinus rhythm (SR). The changes of proteome and acetylome in the AF-LAA vs SR-LAA tissues were studied using dimethyl-labeling, HPLC fractionation, affinity enrichment, LC-MS/MS analysis, database Search and bioinformatic analysis. The acetylated levels of each lysine acetylated site were normalized on the basis of the corresponding protein abundance.

Results

The bioinformatic analysis indicates 294 up-regulated (AF/SR ratio >1.3) proteins and 169 down-regulated (AF/SR ratio <1/1.3) proteins in the AF-LAA vs SR-LAA were detected. Moreover, 3,880 sites in 1,044 proteins were quantified. Motif analysis of the identified acetylated peptides indicated that a total of 14 significantly enriched amino acid sequence motifs from −10 to +10 surrounding the acetylated lysine (Kac) were defined according to 3412 peptides from 1115 proteins. Among the quantified acetylated sites and proteins, 231 up-regulated acetylated sites in 130 proteins and 121 down-regulated acetylated sites in 74 proteins were detected. The enrichment-based clustering analysis showed that energy metabolism and cardiac contraction-related proteins were highly differentially expressed in the AF-LAA vs SR-LAA. Meanwhile, the protein-protein interaction network of the differentially expressed acetylated proteins demonstrated that there were 146 nodes and 569 interactions in the network and quite a lot of interactions in energy metabolism-related proteins and in cardiac contraction-related proteins. Furthermore, the acetylated levels of most differentially expressed energy metabolism-related proteins involving in oxidative phosphorylation, TCA cycle, respiratory ETC, fatty acid metabolism were up-regulated. On the contrary, the acetylated levels of most acetylated sites in differentially expressed cardiac contraction-related proteins including the key contraction proteins were down-regulated.

Interaction network of Ac-proteins

Conclusions

This study details and expands our understanding of the changes of proteome and lysine acetylome in the LAA tissues from valvular heart disease patients with AF. The data suggest important expression differences of acetylated proteins related to energy metabolism and cardiac contraction which may be involved in the matrix of AF formation and maintainence.

Acknowledgement/Funding

This work was supported by the grants from the National Natural Science Foundation of China (no. 81600273, no. 81570310, no.81770337 and no.81870258)

Occurrence of perfluorinated compounds in agricultural environment, vegetables, and fruits in regions influenced by a fluorine-chemical industrial park in China

The occurrence of perfluorinated compounds (PFCs) in vegetables and fruits, as well as agricultural environment, was investigated in the downstream regions of Changshu fluorine-chemical industrial park (CFCIP) in China. Twenty-one PFCs were analyzed in irrigation water, agricultural soil, typical vegetables, and fruits, with the maximum total PFC concentrations of 369.9 ng/L, 64.7 ng/g dw, 11.5 ng/g ww, and 10.5 ng/g ww, respectively. Short-chained perfluoroalkyl carboxylic acids (PFCAs) such as perfluorooctanoic acid (PFOA), perfluorobutanoic acid (PFBA), and perfluorohexanoic acid were the dominant PFCs in terms of their concentrations and detection frequency. PFCs in irrigation water and agricultural soils showed a decreasing trend with increasing distance from CFCIP, while this pattern was not observed in agricultural products. The predominant compounds varied in different vegetables and fruits. Simultaneous bioaccumulation of PFBA and PFOA was found in melons and solanaceous species and pears. Leafy vegetables and grapes exhibited high bioaccumulation of PFOA and PFBA, respectively. Health risk assessment by calculating estimated daily intake showed that no direct risk was caused by the consumption of vegetables and fruits for the residents in the investigated regions. However, the tolerable weekly intake of PFOA exceeded the established thresholds for the adult residents. A comprehensive health assessment of the dietary exposure of PFCs, including all exposure pathways, in fluorine-chemical industrial park-impacted regions is needed.

Abstract P3-05-02: Immune profiling of paired primary and recurrent triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease with several molecular subtypes: basal-like1 (BL-1), basal-like 2 (BL-2), mesenchymal (M), and luminal androgen receptor (LAR). Molecular evolution of TNBC through chemotherapy selection pressure is well recognized but poorly understood. In addition, approximately 20% of TNBCs respond to PD-1 or PD-L1 inhibitors. It has been observed that heavily pre-treated patients may not respond well to immunotherapy. This study was carried out to perform immune profiling of paired primary and recurrent TNBC. Here we report the result of the first 10 paired tissue pilot analysis.

Methods: Twenty specimens were identified through an IRB-approved protocol via the City of Hope Biospecimen Repository (2002-2015). Two brain and one bone metastasis specimens were not included due to technical difficulty. Formalin-fixed paraffin embedded (FFPE) sample blocks were cut into 5-mm thick slides and labeled with the following antibodies: CD4, CD8, CD3, FOXP3, CD20, CD33, Pan-CK, and PD-1 using the multiplex IHC opal method. Image acquisition and cell counting were carried out using PerkinElmer Vectra automated quantitative pathology imaging system and inForm software analysis (PerkinElmer, Waltham, MA). mRNA expression profiling was performed using Affymetrix Human Genechip 2.0. Raw data were normalized and processed using Expression Console. Using Vanderbilt TNBC sub-classification tool, we have sub-classified the 20 primary and recurrent TNBC specimens. Tumor mutation burden (TMB) was generated through FoundationOne® platform.

Result: A total of 17 samples were analyzed (M, 5; LAR, 3; BL-1, 4; BL-2, 5). M-subtype had a significantly lower tumor-infiltrating CD3+ T cells (p=0.005), CD8+ T cells (p=0.024), CD4+ T cells (p=0.065) and CD4+FOXP3+ Treg cells (p=0.054), irrespective of the site of metastasis. CD20+ B cells were particularly enriched in BL-1 subtype (p=0.0013, 23.5% of 17 samples). Of 17 samples, 8 had TMB. Seven had low TMB (&lt;10 mut/Mb) and one had intermediate TMB (11 mut/Mb, LAR subtype). The tumor with intermediate TMB had the highest quantity of tumor-infiltrating CD3+ T cells, CD8+ T cells, CD8+PD1+ T cells, and CD4+FOXP3+PD1+ Treg cells compared to the 7 tumors with low TMB. Compared with recurrent tumors, primary tumors had a significantly higher percentage of tumor-infiltrating T cells (TIL). To validate multiplexed IHC results, these samples were evaluated by a licensed pathologist at City of Hope using the International TILs Working Group 2014 guidelines, and there was a good correlation between percent of TILs and CD3+ T cells by IHC approach.

Conclusion: To our knowledge, this is the first study linking tumor immune cell profiles with the TNBC 4 subtypes. Distinctive immune cell patterns were observed among 4 TNBC subtypes. M subtype had significantly lower TILs, which may indicate poor response to checkpoint inhibitors. Further analysis of a total of 50 paired TNBCs is currently underway.

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org

Citation Format: He T-F, Yost S, Schmolze D, Wang R, Rosario A, Tu T, Chu P, Lee P, Yuan Y. Immune profiling of paired primary and recurrent triple negative breast cancer [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 P3-05-02.

Clonal expansion of hepatocytes with a selective advantage occurs during all stages of chronic hepatitis B virus infection

Hepatocyte clone size was measured in liver samples of 21 patients in various stages of chronic hepatitis B virus (HBV) infection and from 21 to 76 years of age. Hepatocyte clones containing unique virus-cell DNA junctions formed by the integration of HBV DNA were detected using inverse nested PCR. The maximum hepatocyte clone size tended to increase with age, although there was considerable patient-to-patient variation in each age group. There was an upward trend in maximum clone size with increasing fibrosis, inflammatory activity and with seroconversion from HBV e-antigen (HBeAg)-positive to HBeAg-negative, but these differences did not reach statistical significance. Maximum hepatocyte clone size did not differ between patients with and without a coexisting hepatocellular carcinoma. Thus, large hepatocyte clones containing integrated HBV DNA were detected during all stages of chronic HBV infection. Using laser microdissection, no significant difference in clone size was observed between foci of HBV surface antigen (HBsAg)-positive and HBsAg-negative hepatocytes, suggesting that expression of HBsAg is not a significant factor in clonal expansion. Laser microdissection also revealed that hepatocytes with normal-appearing histology make up a major fraction of the cells undergoing clonal expansion. Thus, preneoplasia does not appear to be a factor in the clonal expansion detected in our assays. Computer simulations suggest that the large hepatocyte clones are not produced by random hepatocyte turnover but have an as-yet-unknown selective advantage that drives increased clonal expansion in the HBV-infected liver.

Prognostic factors for survival in patients with stage (stg) IV malignant melanoma (MM)

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Background: Prognosis for survival in MM is not uniform with some pts being long-term survivors. Identifying this subset of pts may have implications on surveillance and treatment (tx). Unfortunately, prognostic data available for MM and the utility of AJCC staging in predicting survival is limited. We analyzed prospectively collected data from the NYUCI Interdisciplinary Melanoma Cooperative Group program (IMCG) to identify clinicopathological variables predictive of MM survival. Methods: We identified 185 pts enrolled in the IMCG with MM diagnosed and treated at NYUCI. Demographic, clinical, and tx-related factors were included in the analysis. Kaplan-Meier (KM) survival analysis was used to identify univariate predictors of post-stage IV survival and their independent effect was assessed in a multivariate Cox proportional hazards regression model. Results: Median age at diagnosis (dx) of metastatic MM was 64 years (22–92). Median overall survival: 13.8 months(m) (128 deaths and a median follow up of 18.6 m (4–141) for survivors). Factors identified on univariate analysis at p<0.20 were evaluated in the multivariate model ( table ). Co-morbidities, site and histology of primary melanoma, initial staging, prior loco-regional recurrences, and adjuvant tx of primary melanoma were not associated with MM survival. Univariate analysis also showed significant survival advantage (p value 0.0011) for patients with AJCC stages M1a and M1b (21.6 m and 17.2 m respectively) over those with AJCC stage M1c (9 m). Conclusions: This cohort study of MM identified female gender, nl serum LDH, nl albumin, and solitary organ involvement as independent survival predictors. Patients who received systemic therapy± local measures had survival benefit over those that had surgery and/or radiation alone suggesting a role for systemic treatment in MM. Patients with personal history of another malignancy (n=37) showed a trend towards improved survival. This novel observation needs to be validated and studied further.

[Table: see text]

No significant financial relationships to disclose.

Effect of mebendazole on melanoma xenograft growth through targeting of bcl-2

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Background: Defects in apoptosis are thought to contribute to melanoma chemoresistance, making the anti-apoptotic protein Bcl-2 an attractive therapeutic target. We identified mebendazole (MBZ), a microtubule binding agent, as an inducer of melanoma cytotoxicity via a Bcl-2 dependent mechanism in vitro (Mol Cancer Res, Aug 2008). In the present study, we assessed the effect of MBZ on human melanoma tumor growth and progression in a mouse xenograft model and compared the ability of MBZ to inhibit growth of cultured melanoma cells to that of oblimersen (OBL), an antisense drug targeting Bcl-2. Methods: Growth of human M-14 melanoma xenografts in mice administered MBZ orally at doses from 0.1 to 2 mg were compared to tumor growth in mice receiving 100mg/kg intraperitoneal temozolomide (TMZ) or vehicle alone. Tumor diameter, volume, histopathology, and immunohistochemical staining of caspase 3 and Ki67 were assessed. Bcl-2 phosphorylation was determined by immunoblotting. MBZ and OBL-induced melanoma growth inhibition was analyzed by MTT assay. Results: Anti-melanoma effects of MBZ were dose- dependent up to 1 mg which displayed a 72% reduction in tumor volume compared to vehicle treated mice. This reduction in volume was accompanied by a 46% decrease in proliferating cells and an 81% increase in apoptotic cells. Moreover, 1 mg MBZ inhibited tumor growth as effectively as high dose TMZ, the current melanoma standard of care. Orally administered MBZ treatment resulted in Bcl-2 phosphorylation in vivo, further confirming its mechanism of action. MBZ inhibited growth of melanoma cells in culture more effectively than OBL with GI50 values of 0.32 uM and 7.45 uM, respectively. Conclusions: MBZ safely and effectively inhibits melanoma growth and progression in a xenograft model. A phase II clinical trial investigating MBZ's utility as adjuvant therapy in patients with stage IV, resected melanoma is planned.

No significant financial relationships to disclose.

Tissue mineral distributions are differentially modified by dietary protein deficiency and a murine nematode infection

This study was designed to investigate whether mineral concentrations in the spleen, serum, and liver were modified by challenge infection with a gastrointestinal nematode, by infection dose, or by protein deficiency despite adequate dietary intakes of minerals. BALB/c mice fed protein-sufficient (PS, 24%) or protein-deficient (PD, 3%) diets were infected with 100 L3 of Heligmosomoides bakeri, drug-treated, and then re-infected with either 0, 100, or 200 L3. Protein deficiency and infection, but not dose, independently modified tissue mineral distributions. H. bakeri infection lowered serum iron concentrations in both diet groups. Despite this, PD mice had elevated iron and calcium concentrations and Ca/Zn ratio in the spleen as well as Fe/Zn ratio in liver, but they had reduced calcium, zinc, copper, and sulfur concentrations, and Cu/Zn ratio in the liver. Infection reduced calcium and iron concentrations and the Ca/Zn ratio in the spleen. We suggest that tissue mineral distribution is a consequence of Th2 immune and inflammatory responses induced by infection in PS mice and the switch to predominant Th1 inflammation in PD, nematode-infected mice.

Acute phase nematode infection reduces resting metabolic rate in both protein-sufficient and protein-deficient mice

The objective of this study was to investigate whether protein deficiency concurrent with the acute phase of infection with the murine nematode Heligmosomoides bakeri (Durette-Desset, Kinsella and Forrester, 1972; Tenora and Barus, 2001) affected the resting metabolic rate (RMR) in BALB/c mice, and whether deworming caused RMR to return to normal. Mice fed either a protein-sufficient (PS, 24%) or protein-deficient (PD, 3%) diet were infected with 100 larvae, and then treated with an anthelmintic drug on 9 and 14 days postinfection (dpi). RMR was measured on –2, 2, 7, and 19 dpi. The results showed that protein deficiency did not affect RMR at any of these times. RMR was unchanged immediately following infection (2 vs. –2 dpi) at the time when larvae are first embedded in the serosal musculture. Surprisingly, at 7 dpi when larvae migrate from the serosal musculture into the intestinal lumen, RMR was significantly lower in both diet groups compared with earlier time points. This reduced RMR persisted even after deworming. Possible reasons for these results are discussed.

Imidacloprid induces neurobehavioral deficits and increases expression of glial fibrillary acidic protein in the motor cortex and hippocampus in offspring rats following in utero exposure

Imidacloprid, a neonicotinoid, is one of the fastest growing insecticides in use worldwide because of its selectivity for insects. The potential for neurotoxicity following in utero exposure to imidacloprid is not known. Timed pregnant Sprague-Dawley rats (300-350 g) on d 9 of gestation were treated with a single intraperitoneal injection (i.p.) of imidacloprid (337 mg/kg, 0.75 x LD50, in corn oil). Control rats were treated with corn oil. On postnatal day (PND) 30, all male and female offspring were evaluated for (a) acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity, (b) ligand binding for nicotinic acetylcholine receptors (nAChR) and muscarinic acetylcholine receptors (m2 mAChR), (c) sensorimotor performance (inclined plane, beam-walking, and forepaw grip), and (d) pathological alterations in the brain (using cresyl violet and glial fibrillary acidic protein [GFAP] immunostaining). The offspring of treated mothers exhibited significant sensorimotor impairments at PND 30 during behavioral assessments. These changes were associated with increased AChE activity in the midbrain, cortex and brainstem (125-145% increase) and in plasma (125% increase). Ligand binding densities for [3H]cytosine for alpha4beta2 type nAchR did not show any significant change, whereas [3H]AFDX 384, a ligand for m2mAChR, was significantly increased in the cortex of offspring (120-155% increase) of imidacloprid-treated mothers. Histopathological evaluation using cresyl violet staining did not show any alteration in surviving neurons in various brain regions. On the other hand, there was a rise in GFAP immunostaining in motor cortex layer III, CA1, CA3, and the dentate gyrus subfield of the hippocampus of offspring of imidacloprid-treated mothers. The results indicate that gestational exposure to a single large, nonlethal, dose of imidacloprid produces significant neurobehavioral deficits and an increased expression of GFAP in several brain regions of the offspring on PND 30, corresponding to a human early adolescent age. These changes may have long-term adverse health effects in the offspring.

Mechanisms underlying reduced expulsion of a murine nematode infection during protein deficiency

Balb/c mice infected with the gastrointestinal nematode Heligmosomoides bakeri were fed protein sufficient (PS, 24%) or deficient (PD, 3%) diets to investigate whether diet, infection or dose of larval challenge (0, 100 or 200 larvae) influenced gut pathophysiology and inflammation. Among the PS mice, worms were more posteriorad in the intestine of mice infected with 200 compared with 100 larvae, suggesting active expulsion in the more heavily infected mice. This was consistent with the positive correlation between worm numbers and fluid leakage in PS mice; similar patterns were not detected in the PD mice. Infection also induced villus atrophy, which was more pronounced in PS than in PD mice. Our cytokine screening array indicated that infection in PD mice elevated a wide range of pro-inflammatory cytokines and chemokines. Whereas serum leptin concentrations were higher in PD mice, monocyte chemotactic protein-5 (MCP-5) in serum increased with increasing larval dose and concentrations were lower in PD than PS mice. We suggest that elevated MCP-5 together with villus atrophy may contribute to the apparent dose-dependent expulsion of H. bakeri from PS mice but that delayed expulsion in PD mice appeared related to a predominant Th1 cytokine profile that may be driven by leptin.

Re-feeding rapidly restores protection againstHeligmosomoides bakeri(Nematoda) in protein-deficient mice

This study determined whether the timing of re-feeding of protein-deficient mice restored functional protection against the gastrointestinal nematode,Heligmosomoides bakeri. Balb/c mice were fed a 3% protein-deficient (PD) diet and then transferred to 24% protein-sufficient (PS) diet either on the day of primary infection, 10 days after the primary infection, on the day of challenge infection, or 7 days after the challenge infection. Control mice were fed either the PD or PS diet. Onset of challenge, but not primary, infection caused short-term body weight loss, anorexia and reduced feed efficiency. Weight gain was delayed in mice when re-feeding commenced on the day of challenge infection; alkaline phosphatase (ALP) was also elevated in these mice on day 28 post-challenge. In contrast, other re-feeding groups attained similar body weights to PS mice within 4 days and had similar ALP at day 28. Serum leptin was higher in PD than PS mice and positively associated with food intake. As expected, worm survival was prolonged in mice fed the PD diet. However, egg production and worm burdens were similar in all re-feeding groups to the PS mice, indicating that protein re-feeding during either the primary or challenge infection rapidly restored normal parasite clearance.

Mild energy restriction alters mouse–nematode transmission dynamics in free-running indoor arenas

Energy restriction reduces Heligmosomoides polygyrus (Dujardin, 1845) (Nematoda) infection by reducing transmission-related behaviours but prolongs parasite survival by suppressing immune responses in individually housed mice. To determine the relative importance of these two processes in accumulation of worms in mouse populations, 10 female CD1 mice were housed in each of eight indoor arenas with ad libitum access to either an energy-sufficient (ES) diet or an energy-restricted (ER) diet with 20% less metabolizable energy (four arenas per diet). After 3 weeks, H. polygyrus transmission was initiated by introducing larvae onto damp peat trays. Mice adapted to the ER diet through increased food intake and nesting and reduced overall activity; after 6 weeks, nutritional and immunological measures were comparable between diet groups. With continuing exposure to parasite larvae, mice in both ER and ES arenas developed resistance to the incoming larvae; however, mice in the ER arenas accumulated lower worm burdens than mice in the ES arenas despite their increased contact with peat. We suggest that the comparable immunocompetence of mice in the ER and ES arenas enabled the ER mice exposed to higher transmission rates to more rapidly reject the parasites, leading to lower final worm numbers, a pattern frequently observed in other helminth infections.

Age and gender related changes in stereoselective pharmacokinetics and pharmacodynamics of verapamil and norverapamil

1. Pharmacokinetics and pharmacodynamics of R- and S-verapamil and R- and S-norverapamil were studied at steady state following administration of 180 mg verapamil delivered by a controlled-release gastrointestinal therapeutic system (COER-verapamil). 2. Of the 30 young (19 to 43 years) and 30 elderly subjects (65 to 80 years) enrolled, approximately half of each age group were women; all subjects were healthy and none were smokers. 3. Mean R- and S-verapamil and R- and S-norverapamil Cmax, Cmin, and AUC values for elderly subjects were 1.2 to 2.2 times greater than those for young subjects; these differences were statistically significant at P < 0.05. Median tmax values for young and elderly subjects were not significantly different for any enantiomer. The mean half-life values of R- and S-verapamil for elderly subjects were approximately 20 h compared with approximately 13 h for young subjects, respectively. The mean half-life values of R- and S-norverapamil for elderly subjects were approximately 31 h and 20 h, respectively, compared with approximately 19 h and 21 h for young subjects, respectively. 4. In both age groups, the mean plasma verapamil concentrations of each enantiomer were higher for women than for men at all time points. 5. Mean arterial pressure (MAP) had a significant correlation to R- (r2 = 0.86) and S-verapamil (r2 = 0.87) concentration values that was not influenced by either gender or age of the patient. Change in PR-interval also had a significant correlation to R- and S-verapamil concentration values. However, the sensitivity of the response to changes in R- and S-verapamil concentration values in elderly subjects was about 1/5 of that in younger subjects.

Absence of cyclin D1/PRAD1 point mutations in human breast cancers and parathyroid adenomas and identification of a new cyclin D1 gene polymorphism

PRAD1 (cyclin D1) has been implicated in the molecular pathogenesis of a variety of tumors, including parathyroid adenomas, t(11;14)-bearing B-lymphoid tumors, and breast cancer. The sequence of the overexpressed PRAD1 genes has been directly analyzed in only two tumor specimens, a benign parathyroid adenoma and a malignant centrocytic lymphoma. Thus, little is known about PRAD1 sequence in the vast majority of human primary tumors, including breast cancers. Using single-strand conformational polymorphism (SSCP) analysis, we have examined the coding region of the PRAD1 gene in 30 primary breast cancers and 25 parathyroid adenomas. Polymerase chain reaction (PCR)-SSCP analysis of the coding region of exons 1-5 of the PRAD1 gene did not reveal any tumor-specific mutations. During the course of screening for mutations, we found and established the sequence variants of a new DNA polymorphism at codon 241 within exon 4 of the PRAD1 gene. Since this polymorphism is located within the coding region of the PRAD1 gene, it will allow determination of allele-specific expression of the gene and the detection of allele imbalance. At least in breast and parathyroid neoplasms, overexpression of the wild-type PRAD1 sequence, rather than point mutational activation, appears to be the predominant mechanism by which PRAD1 exerts its oncogenic action.