Clinical outcomes of percutaneous transforaminal endoscopic decompression for the treatment of degenerative lumbar scoliosis associated with spinal stenosis in elderly individuals: a matched comparison study.

PURPOSE: This retrospective cohort study evaluated the efficacy and safety of percutaneous transforaminal endoscopic decompression (PTED) in elderly patients with degenerative lumbar scoliosis (DLS) associated with lumbar spinal stenosis (LSS). STUDY DESIGN: A matched comparison study. METHODS: In total, 97 patients with DLS associated with LSS who underwent PTED under local anesthesia between 2016 and 2021 were retrospectively analyzed. Using the inclusion and exclusion criteria, 24 patients aged ≥ 80 years were screened and included in the study group. Then, 24 patients aged 50-80 years were matched according to gender, date of surgery, and surgical levels were included in the control group. Clinical outcomes such as the visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, modified MacNab criteria, radiological parameters, and complications were assessed. The independent sample t-test, Pearson's chi-square test and Fisher's exact test were used to compare the parameters between the study and control groups. RESULTS: The study group had significantly higher mean American Society of Anesthesiologists classification and age-adjusted Charlson Comorbidity Index scores than the control group (2.42 ± 0.72) vs. 5.25 ± 1.03 and 1.67 ± 0.76 vs. 3.17 ± 2.10, respectively). The VAS scores for pain in two legs and back and ODI scores significantly improved at two weeks after surgery and at the final followup (p < 0.05). The study group had higher back pain VAS and ODI scores than the control group at the final followup (p < 0.05). In addition, the complication and patient satisfaction rates were similar between the two groups (p > 0.05). The overall radiological parameters were comparable between the two groups, and there was no significant deterioration in coronal imbalance or loss of disc height between the two groups. CONCLUSION: Elderly patients (aged ≥ 80 years) with DLS associated with LSS are less fit and have a greater number of comorbidities. However, they can achieve satisfactory outcomes with PTED, which are comparable to those of patients < 80 years. PTED under local anesthesia can also be an efficient alternative to conventional open lumbar decompression surgery for treating elderly patients with comorbidities.

Deep learning assisted segmentation of the lumbar intervertebral disc: a systematic review and meta-analysis.

BACKGROUND: In recent years, deep learning (DL) technology has been increasingly used for the diagnosis and treatment of lumbar intervertebral disc (IVD) degeneration. This study aims to evaluate the performance of DL technology for IVD segmentation in magnetic resonance (MR) images and explore improvement strategies. METHODS: We developed a PRISMA systematic review protocol and systematically reviewed studies that used DL algorithm frameworks to perform IVD segmentation based on MR images published up to April 10, 2024. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess methodological quality, and the pooled dice similarity coefficient (DSC) score and Intersection over Union (IoU) were calculated to evaluate segmentation performance. RESULTS: 45 studies were included in this systematic review, of which 16 provided complete segmentation performance data and were included in the quantitative meta-analysis. The results indicated that DL models showed satisfactory IVD segmentation performance, with a pooled DSC of 0.900 (95% confidence interval [CI]: 0.887-0.914) and IoU of 0.863 (95% CI: 0.730-0.995). However, the subgroup analysis did not show significant effects of factors on IVD segmentation performance, including network dimensionality, algorithm type, publication year, number of patients, scanning direction, data augmentation, and cross-validation. CONCLUSIONS: This study highlights the potential of DL technology in IVD segmentation and its further applications. However, due to the heterogeneity in algorithm frameworks and result reporting of the included studies, the conclusions should be interpreted with caution. Future research should focus on training generalized models on large-scale datasets to enhance their clinical application.

The trajectory of vesicular proteomic signatures from HBV-HCC by chitosan-magnetic bead-based separation and DIA-proteomic analysis.

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer often associated with chronic hepatitis B virus infection (CHB) and liver cirrhosis (LC), underscoring the critical need for biomarker discovery to improve patient outcomes. Emerging as a promising avenue for biomarker development, proteomic technology leveraging liquid biopsy from small extracellular vesicles (sEV) offers new insights. Here, we evaluated various methods for sEV isolation and identified polysaccharide chitosan (CS) as an optimal approach. Subsequently, we employed optimized CS-based magnetic beads (Mag-CS) for sEV separation from serum samples of healthy controls, CHB, LC, and HBV-HCC patients. Leveraging data-independent acquisition mass spectrometry coupled with machine learning, we uncovered potential vesicular protein biomarker signatures (KNG1, F11, KLKB1, CAPNS1, CDH1, CPN2, NME2) capable of distinguishing HBV-HCC from CHB, LC, and non-HCC conditions. Collectively, our findings highlight the utility of Mag-CS-based sEV isolation for identifying early detection biomarkers in HBV-HCC.

A case report and literature review on TP53 gene mutation in a bladder rhabdomyosarcoma patient.

Background: Rhabdomyosarcoma of the bladder is an infrequent neoplastic condition characterized by a pronounced malignant situation with challenges in treatment due to the lack of standardized guidelines and large-scale of clinical studies. The patient in this case is tested TP53 mutation that may provide new diagnostic and therapeutic options. Case presentation: Here, we reported a 34-year-old male who received bladder tumor resection, and diagnosed as bladder rhabdomyosarcoma with TP53 mutation after the pathology test. This patient underwent 6 rounds of chemotherapy. However, the pelvic tumor recurred 11 months after the first surgery. So, the patient accepted the pelvic tumor resection. Only 3 months after the surgical intervention, the patient underwent abdominal massive metastasis and ultimately succumbed to the illness six months following the second surgery. The course of the illness was 22 months. Conclusion: Bladder rhabdomyosarcoma is a disease with an extremely poor prognosis. Genetic testing holds significant value in the diagnosis and treatment. Perhaps targeted therapy against TP53 is potential valuable for such rare diseases.

Intratumoral Escherichia Is Associated With Improved Survival to Single-Agent Immune Checkpoint Inhibition in Patients With Advanced Non-Small-Cell Lung Cancer.

PURPOSEThe impact of the intratumoral microbiome on immune checkpoint inhibitor (ICI) efficacy in patients with non-small-cell lung cancer (NSCLC) is unknown. Preclinically, intratumoral Escherichia is associated with a proinflammatory tumor microenvironment and decreased metastases. We sought to determine whether intratumoral Escherichia is associated with outcome to ICI in patients with NSCLC.PATIENTS AND METHODSWe examined the intratumoral microbiome in 958 patients with advanced NSCLC treated with ICI by querying unmapped next-generation sequencing reads against a bacterial genome database. Putative environmental contaminants were filtered using no-template controls (n = 2,378). The impact of intratumoral Escherichia detection on overall survival (OS) was assessed using univariable and multivariable analyses. The findings were further validated in an external independent cohort of 772 patients. Escherichia fluorescence in situ hybridization (FISH) and transcriptomic profiling were performed.RESULTSIn the discovery cohort, read mapping to intratumoral Escherichia was associated with significantly longer OS (16 v 11 months; hazard ratio, 0.73 [95% CI, 0.59 to 0.92]; P = .0065) in patients treated with single-agent ICI, but not combination chemoimmunotherapy. The association with OS in the single-agent ICI cohort remained statistically significant in multivariable analysis adjusting for prognostic features including PD-L1 expression (P = .023). Analysis of an external validation cohort confirmed the association with improved OS in univariable and multivariable analyses of patients treated with single-agent ICI, and not in patients treated with chemoimmunotherapy. Escherichia localization within tumor cells was supported by coregistration of FISH staining and serial hematoxylin and eosin sections. Transcriptomic analysis correlated Escherichia-positive samples with expression signatures of immune cell infiltration.CONCLUSIONRead mapping to potential intratumoral Escherichia was associated with survival to single-agent ICI in two independent cohorts of patients with NSCLC.

Artificial intelligence automatic measurement technology of lumbosacral radiographic parameters.

Background: Currently, manual measurement of lumbosacral radiological parameters is time-consuming and laborious, and inevitably produces considerable variability. This study aimed to develop and evaluate a deep learning-based model for automatically measuring lumbosacral radiographic parameters on lateral lumbar radiographs. Methods: We retrospectively collected 1,240 lateral lumbar radiographs to train the model. The included images were randomly divided into training, validation, and test sets in a ratio of approximately 8:1:1 for model training, fine-tuning, and performance evaluation, respectively. The parameters measured in this study were lumbar lordosis (LL), sacral horizontal angle (SHA), intervertebral space angle (ISA) at L4-L5 and L5-S1 segments, and the percentage of lumbar spondylolisthesis (PLS) at L4-L5 and L5-S1 segments. The model identified key points using image segmentation results and calculated measurements. The average results of key points annotated by the three spine surgeons were used as the reference standard. The model's performance was evaluated using the percentage of correct key points (PCK), intra-class correlation coefficient (ICC), Pearson correlation coefficient (r), mean absolute error (MAE), root mean square error (RMSE), and box plots. Results: The model's mean differences from the reference standard for LL, SHA, ISA (L4-L5), ISA (L5-S1), PLS (L4-L5), and PLS (L5-S1) were 1.69°, 1.36°, 1.55°, 1.90°, 1.60%, and 2.43%, respectively. When compared with the reference standard, the measurements of the model had better correlation and consistency (LL, SHA, and ISA: ICC = 0.91-0.97, r = 0.91-0.96, MAE = 1.89-2.47, RMSE = 2.32-3.12; PLS: ICC = 0.90-0.92, r = 0.90-0.91, MAE = 1.95-2.93, RMSE = 2.52-3.70), and the differences between them were not statistically significant (p > 0.05). Conclusion: The model developed in this study could correctly identify key vertebral points on lateral lumbar radiographs and automatically calculate lumbosacral radiographic parameters. The measurement results of the model had good consistency and reliability compared to manual measurements. With additional training and optimization, this technology holds promise for future measurements in clinical practice and analysis of large datasets.

Percutaneous Transforaminal Endoscopic Discectomy for Adjacent Segment Disease versus Lumbar Disc Herniation in Elderly Patients.

Purpose: Percutaneous transforaminal endoscopic discectomy (PTED) was used as a minimally invasive treatment option for lumbar disc herniation (LDH). However, studies focusing on the clinical outcomes of PTED for elderly patients with adjacent segment disease (ASD) were limited. This study aims to compare the clinical outcomes of PTED between ASD and LDH in elderly patients. Patients and Methods: This retrospective study enrolled 39 patients with ASD and 39 patients with LDH. Both groups had undergone PTED in Beijing Chaoyang Hospital from July 4, 2016 to July 30, 2021. Visual analog scale for back pain (VAS-BP) and leg pain (VAS-LP) and Oswestry disability index (ODI) were used to value the clinical outcomes of patients preoperatively, immediately postoperatively, 12, and 24 months postoperatively, and at final follow-up. Patients' satisfaction was evaluated based on the MacNab criteria. Results: All operations were completed. The excellent or good clinical outcomes at final follow-up was demonstrated by 87.15% (34/39) and 89.74% (35/39) in ASD and non-ASD patients, respectively. Clinical improvement was observed immediately postoperatively in both groups and sustained stability during the postoperative follow-up. The ASD group demonstrated significantly longer hospital stays (p = 0.02) and operative time (p < 0.01) than the non-ASD group. Conclusion: PTED is an effective and minimally invasive treatment option for revision surgery of ASD, especially for elderly patients. However, the long-term prognosis of PTED treating ASD still needs further exploration.

Recompression after percutaneous transforaminal endoscopic decompression for degenerative lumbar spinal stenosis: risk factors and outcomes of two different reoperation procedures.

Purpose: To determine the risk factors for recompression after percutaneous transforaminal endoscopic decompression (PTED) for the treatment of degenerative lumbar spinal stenosis (DLSS) and compare the outcomes of PTED and posterior lumbar interbody fusion (PLIF) as revision surgery. Methods: We retrospectively evaluated 820 consecutive DLSS patients who underwent PTED at our institution. 26 patients developed postoperative recompression and underwent reoperation. In total, 208 patients with satisfactory clinical outcomes were enrolled in the control group. The demographic and imaging data of each patient were recorded. Univariate and multivariate analyses were performed to assess risk factors for recompression. Additionally, patients with recompression were divided into PTED and PLIF groups according to the reoperation procedure. The clinical outcomes of the two groups were compared using independent-sample t-tests. Results: The grade of surgical-level disc degeneration [odds ratio (OR): 2.551, p = 0.045] and the number of disc degeneration levels (OR: 11.985, p < 0.001) were independent risk factors for recompression after PTED. There was no significant difference in the visual analog score (VAS) and Oswestry disability index (ODI) two weeks postoperatively between the PTED and PLIF groups for surgical treatment. However, the mean VAS of back pain (14.1 vs. 20.5, p = 0.016) and ODI (16.0 vs. 21.8, p = 0.016) of patients in the PLIF group were smaller than those in the PTED group at the final follow-up. Conclusion: More severe degeneration and degenerated levels indicate a higher recompression rate after PTED. Although both PTED and PLIF could achieve immediate relief postoperatively in the treatment of recompression, the final follow-up results showed that the outcome of PLIF appeared better than that of PTED.

Characterization of a monkey model with experimental retinal damage induced by N-methyl-D-aspartate.

N-methyl-D-aspartate (NMDA)-induced retinal damage has been well studied in rodents, but the detailed mechanisms have not yet been characterized in nonhuman primates. Here, we characterized the retinal degenerative effects of NMDA on rhesus monkeys in vivo. NMDA saline or saline-only control was injected intravitreally to the randomly assigned eyes and contralateral eyes of four rhesus monkeys, respectively. The structural and functional changes of retina were characterized by optical coherence tomography and electroretinography on days 0, 4, 30 and 60 post injection. Both optic discs and macular areas of the NMDA-injected eyes initially presented with a transient retinal thickening, followed by continued retinal thinning. The initial, transient retinal thickening has also been observed in glaucoma patients, but this has not been reported in rodent NMDA models. This initial response was followed by loss of retina ganglion cells (RGCs), which is similar to glaucomatous optic neuropathy and other RGC-related retinal degenerations. The amplitudes of both the photopic negative response and pattern electroretinogram decreased significantly and remained low until the end of the study. Thus, the NMDA monkey model may serve as a more clinically relevant animal model of retinal damage.

Development of a software system for surgical robots based on multimodal image fusion: study protocol.

Background: Surgical robots are gaining increasing popularity because of their capability to improve the precision of pedicle screw placement. However, current surgical robots rely on unimodal computed tomography (CT) images as baseline images, limiting their visualization to vertebral bone structures and excluding soft tissue structures such as intervertebral discs and nerves. This inherent limitation significantly restricts the applicability of surgical robots. To address this issue and further enhance the safety and accuracy of robot-assisted pedicle screw placement, this study will develop a software system for surgical robots based on multimodal image fusion. Such a system can extend the application range of surgical robots, such as surgical channel establishment, nerve decompression, and other related operations. Methods: Initially, imaging data of the patients included in the study are collected. Professional workstations are employed to establish, train, validate, and optimize algorithms for vertebral bone segmentation in CT and magnetic resonance (MR) images, intervertebral disc segmentation in MR images, nerve segmentation in MR images, and registration fusion of CT and MR images. Subsequently, a spine application model containing independent modules for vertebrae, intervertebral discs, and nerves is constructed, and a software system for surgical robots based on multimodal image fusion is designed. Finally, the software system is clinically validated. Discussion: We will develop a software system based on multimodal image fusion for surgical robots, which can be applied to surgical access establishment, nerve decompression, and other operations not only for robot-assisted nail placement. The development of this software system is important. First, it can improve the accuracy of pedicle screw placement, percutaneous vertebroplasty, percutaneous kyphoplasty, and other surgeries. Second, it can reduce the number of fluoroscopies, shorten the operation time, and reduce surgical complications. In addition, it would be helpful to expand the application range of surgical robots by providing key imaging data for surgical robots to realize surgical channel establishment, nerve decompression, and other operations.

Homocysteine levels in first-episode patients with psychiatric disorders.

A high homocysteine (Hcy) level is a risk factor for schizophrenia, depression, and bipolar disorder. However, the role of hyperhomocysteinemia as either an independent factor or an auxiliary contributor to specific psychiatric symptoms or disorders remains unclear. This study aimed to examine Hcy levels in first-episode inpatients with psychotic symptoms and various psychiatric diseases to elucidate the association between Hcy levels and psychiatric disorders. This study enrolled 191 patients (aged 18-40 years) with psychiatric disorders. Seventy-five patients were diagnosed with schizophrenia, 48 with acute and transient psychotic disorders, 36 with manic episodes with psychosis, 32 with major depressive episodes with psychosis, and 56 healthy controls. Serum Hcy levels were measured using the enzyme cycle method. A Hcy concentration level of > 15 µmol/L was defined as hyperhomocysteinemia. Hcy levels were significantly higher in first-episode patients with psychiatric disorders compared to healthy controls (5.99 ± 3.60 vs. 19.78 ± 16.61 vs. 15.50 ± 9.08 vs. 20.00 ± 11.33 vs. 16.22 ± 12.06, F = 12.778, P < 0.001). Hcy levels were significantly higher in males with schizophrenia, acute and transient psychotic disorder, and major depressive disorder but not in mania [schizophrenia, (t = -4.727, P < 0.001); acute and transient psychotic disorders, (t = -3.389, P = 0.001); major depressive episode with psychosis, (t = -3.796, P < 0.001); manic episodes with psychosis, (t = -1.684, P = 0.101)]. However, serum Hcy levels were not significantly different among the psychiatric disorder groups (F = 0.139, P = 0.968). Multivariate linear regression showed that males had an increased risk for homocysteinemia. (95% CI = 8.192-15.370, P < 0.001). These results suggest that first-episode patients with psychiatric disorders have higher Hcy levels than in the general population, and men are at greater risk for psychiatric disorders. In conclusion, elevated Hcy levels may contribute to the pathogenesis of first-episode patients with psychotic symptoms.

Percutaneous transforaminal endoscopic discectomy for Upper Lumbar Disc Herniation versus lower lumbar disc herniation: clinical outcomes and technical consideration.

BACKGROUND: Upper lumbar disc herniation (ULDH) accounts for 1-10% of all lumbar disc herniations (LDH). This study aimed to evaluate the clinical characteristics and outcomes of patients with ULDH who underwent percutaneous transforaminal endoscopic discectomy (PTED) compared with those with lower LDH. METHODS: 60 patients with ULDH or L4-L5 LDH treated with PTED between May 2016 and October 2021. MacNab criteria, visual analog scale (VAS) of back pain and leg pain, and Japanese Orthopedic Association (JOA) were evaluated before and after surgery. RESULTS: In the L1-L3 group, 59.1% of the patients had a positive femoral nerve tension test, and 81.8% of the patients had a sensory deficit. Both groups showed significant improvements in VAS scores for low back and leg pain, and JOA scores postoperatively. No significant differences in the degree of improvement were observed between the two groups. The excellent/good rate was 81.8% in the L1-L3 group and 84.2% in the L4-L5 group, showing no significant difference. CONCLUSION: PTED has comparable efficacy in treating ULDH as it does in treating lower LDH, it is a safe and effective treatment method for ULDH.

Comparative analysis of arthroscopic technique for anterior talofibular and calcaneofibular ligament reconstruction versus open modified brostrom-gould procedure in chronic lateral ankle instability management.

BACKGROUND: Chronic Lateral Ankle Instability (CLAI) is a common condition treated using either Anterior Talofibular and Calcaneofibular Ligament (ATFL and CFL) reconstruction or Modified Brostrom Procedure (MBP). However, the comparative efficacy of these approaches is not well-studied. METHODS: In this study, clinical data were retrospectively collected from 101 patients diagnosed with CLAI who underwent either ATFL and CFL reconstruction (n = 51) or the MBP (n = 50). Patients were comparable in terms of age, sex, Body Mass Index (BMI), post-injury duration, preoperative American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, Visual Analog Score (VAS), Anterior Talar Translation, and Talar Tilt Angle. RESULTS: The post-operative measures showed no significant differences in AOFAS Score, Karlsson Score, and VAS between both treatment groups. However, patients who underwent ATFL and CFL reconstruction showed significantly lower follow-up Anterior Talar Translation (mean = 4.1667 ± 1.3991 mm) and Talar Tilt Angle (mean = 5.0549 ± 1.6173°) compared to those who underwent MBP. Further, patients treated with ATFL and CFL reconstruction experienced a significantly longer postoperative recovery time (median = 6 weeks) compared to MBP (median = 3 weeks). CONCLUSIONS: Although both therapeutic techniques were generally effective in treating CLAI, the ATFL and CFL reconstruction approach delivered superior control of Anterior Talar Translation and Talar Tilt Angle. However, its longer recovery time merits further study to optimize the balance between therapeutic efficacy and recovery speed.

JNK signaling mediates acute rejection via activating autophagy of CD8+ T cells after liver transplantation in rats.

Background: Acute rejection (AR) after liver transplantation (LT) remains an important factor affecting the prognosis of patients. CD8+ T cells are considered to be important regulatory T lymphocytes involved in AR after LT. Our previous study confirmed that autophagy mediated AR by promoting activation and proliferation of CD8+ T cells. However, the underlying mechanisms regulating autophagy in CD8+ T cells during AR remain unclear. Methods: Human liver biopsy specimens of AR after orthotopic LT were collected to assess the relationship between JNK and CD8+ T cells autophagy. The effect of JNK inhibition on CD8+ T cells autophagy and its role in AR were further examined in rats. Besides, the underlying mechanisms how JNK regulated the autophagy of CD8+ T cells were further explored. Results: The expression of JNK is positive correlated with the autophagy level of CD8+ T cells in AR patients. And similar findings were obtained in rats after LT. Further, JNK inhibitor remarkably inhibited the autophagy of CD8+ T cells in rat LT recipients. In addition, administration of JNK inhibitor significantly attenuated AR injury by promoting the apoptosis and downregulating the function of CD8+ T cells. Mechanistically, JNK may activate the autophagy of CD8+ T cells through upregulating BECN1 by inhibiting the formation of Bcl-2/BECN1 complex. Conclusion: JNK signaling promoted CD8+ T cells autophagy to mediate AR after LT, providing a theoretical basis for finding new drug targets for the prevention and treatment of AR after LT.

Effect of butylphthalide on prevention and treatment of high altitude cerebral edema in rats.

3-n-butylphthalide (NBP) contains one of the main active ingredients of celery seed. It has a series of pharmacological mechanisms, including reconstitution of microcirculation, protection of mitochondrial function, inhibition of oxidative stress, and inhibition of neuronal apoptosis. Based on the complex multi-targeting of NBP pharmacological mechanisms, the clinical applications of NBP are increasing, and more and more clinical studies and animal experiments have focused on NBP. In this study, we used male Sprague Dawley rats as an animal model to elucidate the intervention effect of butylphthalide on high altitude cerebral edema (HACE), and also compared the effect of butylphthalide and rhodiola rosea on HACE. Firstly, we measured the changes of body weight and brain water content and observed the pathological changes of brain tissues. In addition, the contents of inflammatory factors, oxidative stress and brain neurotransmitters were assessed by enzyme-linked immunoassay kits, and finally, the expression of apoptotic proteins in brain tissues was determined by western blotting. The results showed that NBP reduced brain water content, attenuated brain tissue damage, altered inflammatory factors, oxidative stress indicators, and brain neurotransmitter levels, and in addition NBP inhibited the expression of Caspase-related apoptotic proteins. Therefore, NBP has the potential to treat and prevent HACE.

Sialylation on vesicular integrin ß1 determined endocytic entry of small extracellular vesicles into recipient cells.

BACKGROUND: Small extracellular vesicles (sEV) are closely associated with the development and metastasis of many types of mammalian cancer. Glycoconjugates are highly expressed on sEV and play important roles in sEV biogenesis and their interaction with other cells. However, the study on vesicular glycoconjugates are far behind proteins and nucleic acids. Especially, the functions of sialic acids which are the terminal components of glycoconjugates, are poorly understood in sEV. METHODS: Sialic acid levels on sEV from plasma and bladder cancer cells were determined by ELISA and lectin blotting. Effects of sialylation on sEV uptake were determined by flow cytometry. Vesicular glycoproteins bearing sialic acids responsible for sEV uptake was identified by proteomics and density gradient centrifugation, and their site-specific sialylation functions were assayed by N-glycosylation site mutation. Effects of integrin ß1 bearing sialic acids on the pro-metastatic function of sEV in vivo were explored using Balb/c nu/nu mice. RESULTS: (1) Increased sialic acid levels were observed in sEV from malignant bladder cancer cells. (2) Elimination of sialic acids on sEV impaired sEV uptake by recipient cells. (3) Vesicular integrin ß1 bearing sialic acids was identified to play a key role in sEV uptake. (4) Desialylation of the hybrid domain of vesicular integrin ß1 inhibited its binding to matrix fibronectin, and reduced sEV entry into recipient cells. (5) Sialylation on integrin ß1 affected pro-metastatic function of sEV in Balb/c nu/nu mice. CONCLUSIONS: Taken together, our findings indicate important functional roles of sialic acids in sEV uptake and reprogramming plasticity of surrounding normal epithelial cells.

ERG activates a stem-like proliferation-differentiation program in prostate epithelial cells with mixed basal-luminal identity.

To gain insight into how ERG translocations cause prostate cancer, we performed single cell transcriptional profiling of an autochthonous mouse model at an early stage of disease initiation. Despite broad expression of ERG in all prostate epithelial cells, proliferation was enriched in a small, stem-like population with mixed-luminal basal identity (called intermediate cells). Through a series of lineage tracing and primary prostate tissue transplantation experiments, we find that tumor initiating activity resides in a subpopulation of basal cells that co-express the luminal genes Tmprss2 and Nkx3.1 (called BasalLum) but not in the larger population of classical Krt8+ luminal cells. Upon ERG activation, BasalLum cells give rise to the highly proliferative intermediate state, which subsequently transitions to the larger population of Krt8+ luminal cells characteristic of ERG-positive human cancers. Furthermore, this proliferative population is characterized by an ERG-specific chromatin state enriched for NFkB, AP-1, STAT and NFAT binding, with implications for TF cooperativity. The fact that the proliferative potential of ERG is enriched in a small stem-like population implicates the chromatin context of these cells as a critical variable for unmasking its oncogenic activity.

The neuroendocrine transition in prostate cancer is dynamic and dependent on ASCL1.

Lineage plasticity is a recognized hallmark of cancer progression that can shape therapy outcomes. The underlying cellular and molecular mechanisms mediating lineage plasticity remain poorly understood. Here, we describe a versatile in vivo platform to identify and interrogate the molecular determinants of neuroendocrine lineage transformation at different stages of prostate cancer progression. Adenocarcinomas reliably develop following orthotopic transplantation of primary mouse prostate organoids acutely engineered with human-relevant driver alterations (e.g., Rb1-/-; Trp53-/-; cMyc+ or Pten-/-; Trp53-/-; cMyc+), but only those with Rb1 deletion progress to ASCL1+ neuroendocrine prostate cancer (NEPC), a highly aggressive, androgen receptor signaling inhibitor (ARSI)-resistant tumor. Importantly, we show this lineage transition requires a native in vivo microenvironment not replicated by conventional organoid culture. By integrating multiplexed immunofluorescence, spatial transcriptomics and PrismSpot to identify cell type-specific spatial gene modules, we reveal that ASCL1+ cells arise from KRT8+ luminal epithelial cells that progressively acquire transcriptional heterogeneity, producing large ASCL1+;KRT8- NEPC clusters. Ascl1 loss in established NEPC results in transient tumor regression followed by recurrence; however, Ascl1 deletion prior to transplantation completely abrogates lineage plasticity, yielding adenocarcinomas with elevated AR expression and marked sensitivity to castration. The dynamic feature of this model reveals the importance of timing of therapies focused on lineage plasticity and offers a platform for identification of additional lineage plasticity drivers.

Tumorigenesis driven by the BRAFV600E oncoprotein requires secondary mutations that overcome its feedback inhibition of migration and invasion.

BRAFV600E mutation occurs in 46% of melanomas and drives high levels of ERK activity and ERK-dependent proliferation. However, BRAFV600E is insufficient to drive melanoma in GEMM models, and 82% of human benign nevi harbor BRAFV600E mutations. We show here that BRAFV600E inhibits mesenchymal migration by causing feedback inhibition of RAC1 activity. ERK pathway inhibition induces RAC1 activation and restores migration and invasion. In cells with BRAFV600E, mutant RAC1, overexpression of PREX1, PREX2, or PTEN inactivation restore RAC1 activity and cell motility. Together, these lesions occur in 48% of BRAFV600E melanomas. Thus, although BRAFV600E activation of ERK deregulates cell proliferation, it prevents full malignant transformation by causing feedback inhibition of cell migration. Secondary mutations are, therefore, required for tumorigenesis. One mechanism underlying tumor evolution may be the selection of lesions that rescue the deleterious effects of oncogenic drivers.