Elevated Expression Research Articles

Plumage polymorphism in the black sparrowhawk (Accipiter melanoleucus) is strongly associated with expression level of agouti signalling protein

Abstract Melanin-based plumage polymorphisms in birds are often associated with mutations in the melanogenesis genes, notably the melanocortin-1 receptor (MC1R), but may also arise through changes in the expression of these genes. Here we investigate the molecular basis of plumage polymorphism in both adult and juvenile black sparrowhawks (Accipiter melanoleucus), an African raptor that occurs in two adult colour morphs, light and dark, and also exhibits variation in juvenile plumage colouration. Our results confirmed that plumage differences in adult morphs were a result of differential deposition of eumelanin in their ventral contour feathers. No polymorphisms in the coding regions of the MC1R or the agouti signalling protein (ASIP) genes associated with adult colour morph were identified. However, lack of pigmentation in the developing breast feathers of light morph birds was strongly associated with elevated ASIP expression, and concomitant down-regulation of the downstream melanogenesis genes microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein 1 (TYRP1). Variation in the rufous coloured plumage of juveniles was found to be due to covariation in eumelanin and pheomelanin levels in dorsal and ventral contour feathers. As in adult birds, an inverse relationship between melanin pigmentation and ASIP expression was observed. This covariation between eumelanin and pheomelanin levels is not consistent with the pigment type-switching model of melanogenesis, where increased ASIP expression results in a switch from eumelanin to pheomelanin production. This highlights the need for caution when extrapolating results from model systems to other animals and the value of conducting research in wild species.

Elevated expression of APOO as a potential prognostic marker in breast cancer: insights from bioinformatic analysis and experimental validation

Elevated expression of APOO as a potential prognostic marker in breast cancer: insights from bioinformatic analysis and experimental validation

Abstract A031: ECM architecture drives distinct evolutionary patterns of tumor immune escape and elimination in breast cancer

Abstract Cancer progression poses a clinical hurdle due to tumor heterogeneity that contributes to treatment resistance and immune evasion. While the adaptive immune system can effectively eliminate cancer in certain instances, tumor escape remains challenging. The immune microenvironment plays an important role in this process. One unanswered question is the role of ECM geometry, also known as Tumor Associated Collagen Signatures (TACS), and its effects on tumor immune recognition. In solid malignancies, ECM geometry has been associated with disease stage and T cell infiltration. Specifically, empirically observed ECM topologies are frequently categorized based on fiber arrangement: random fibers (TACS1), circumferentially aligned fibers (TACS2), and radially arranged fibers (TACS3). Even though a clear negative correlation between TACS and patient survival has been established, the specific roles and extent of TACS in T cell-driven cancer evolution remain uncharacterized. The precise mechanisms underlying how TACS influences cell movement are still not fully elucidated, with divergent opinions on whether and how the ECM mediates immune cell infiltration. At present, we currently lack a physical model relating the impact of TACS on the spatial co-evolution between an adaptive immune repertoire and a heterogeneous population of evading cancer cells. Here, we developed the EVO-ACT (EVOlutionary Agent-based Cancer T cell interaction) model, which is based on the Gillespie algorithm, to study the effects of TACS on tumor evolution and dynamical tumor-T cell interactions. Our analysis of tumor-T cell interactions across three TACS types reveals distinct migration patterns, with TACS3 showing the highest efficiency, TACS1 intermediate, and TACS2 the lowest. TACS impacts T cells more than tumors, with stronger chemokine gradients aiding T cell infiltration. Our model suggests that despite TACS2's limited efficiency, it cannot fully impede T cell infiltration. Varied migration efficiencies lead to diverse T cell infiltration patterns and immunoediting levels. TACS3 shows a benefit to immune recognition and higher survival, contrary to lower survival in TACS3 patients observed clinically in breast cancer. Our results indicate that only after introducing phenotypic changes, such as Epithelial-Mesenchymal Transition (EMT), and noting that EMT occurs exclusively after the TACS2-TACS3 progression, can our findings successfully explain the clinically observed trends. Considering mesenchymal tumor cells' ability to upregulate PD-1/PD-L1, we explore TACS-specific tumor evolution's impact on PD-1/PD-L1 inhibitor responses and patient survival. We observe higher tumor escape rates and lower survival in TACS3 compared to TACS2. Thus, TACS3 alone does not account for lower survival in breast cancer; TACS3-associated late-stage cancer byproducts like EMT and elevated checkpoint expression significantly decrease survival. Citation Format: Yijia Fan, Jason Tomas George. ECM architecture drives distinct evolutionary patterns of tumor immune escape and elimination in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A031.

Abstract B021: Aneuploidy-associated cohesin RAD21 gains promote immune evasion in prostate cancers

Abstract Aneuploidy, characterized by imbalanced chromosome numbers, is a hallmark of cancer and is strongly correlated with lethal progression in prostate cancer. Our recent work identified that gains of chromosome 8q, the most frequently gained chromosome in aneuploidy prostate cancers, drive cancer progression, partially through the cohesin RAD21 gene located on the chr8q24 region. We demonstrated that increased RAD21 expression accelerates lethal progression and oncogenesis in both prostate cancer and Ewing sarcoma by alleviating oncogenic stress during early-stage oncogenesis in both cell line and organoid models. Therefore, we hypothesize that elevated RAD21 levels could enable cancer cells to evade immune surveillance by mitigating oncogenic stress and DNA damage. In this study, we developed isogenic prostate and breast cancer cell culture models with varying levels of RAD21. Using a natural killer (NK) cell co-culture assay, we observed that cells with elevated RAD21 expression were significantly less susceptible to NK-mediated cytotoxicity and exhibited increased survivorship when co-cultured with NK cells. These findings align with publicly available data showing that tumors with high RAD21 levels have reduced NK cell infiltration in prostate cancer. Our results suggest that increased RAD21 expression, commonly associated with chr8q gains, facilitates immune evasion in cancer cells, thereby promoting early-stage oncogenesis. Understanding the role of RAD21 in immune evasion could reveal novel therapeutic strategies targeting immune surveillance mechanisms in prostate cancer. Citation Format: Elise G. DeArment, Ruoxi W. Wang, Kate Lu, Xiaofeng A. Su, Andrew Elliott, Nicholas A. Zorko, Justin H. Hwang, Xiaofeng A. Su. Aneuploidy-associated cohesin RAD21 gains promote immune evasion in prostate cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B021.

Abstract B038: Establishing a screening platform to identify key signaling molecules regulating cold tumor formation through immune evasion and exclusion

Abstract Many trial data have shown that cancer immunotherapy can successfully induce long lasting anti-cancer immune responses and increased the survival rate of cancer patients. One of the key challenges facing cancer immunotherapy is the low response rate of cancer patients to immunotherapy, suggesting that these cancer patients may have acquired resistance toward immunotherapy before treatments. Therefore, there is an unmet need for identifying the underlying mechanisms that promote resistance. One important hypothesis is that immune-excluded tumors (so called cold tumors) that lack of functional T cells have been often found in cancer patients who cannot respond well to cancer immunotherapy. To address this, we have successfully established a preclinical model for cold lung tumors, conducted RNA-seq, performed hallmark gene set enrichment analysis (GSEA) on cold tumor cells sorted in vivo, and identified several candidates associated with epithelial-mesenchymal transition, Wnt signaling, type I and II interferon (IFN) signaling, and p53 signaling. We hypothesize that their roles may either promote or inhibit the formation of cold tumors. One of the molecular candidates we identified, a molecule designated as IRC001, represents a crucial proof of concept for our experimental tumor model. We have unveiled a novel role for IRC001 in enhancing anti-tumor immunity, leading to the transformation of cold tumors into hot tumors and facilitating swift tumor regression through pathways reliant on T cells and type I IFN signaling. Our mechanistic studies have shown that IRC001 can trigger type I IFN signaling by engaging STING/TBK-1/IRF3-dependent pathways. To delve deeper into the spatial and molecular distinctions in mouse tumors (± IRC001), we initiated a preliminary study utilizing 10x Genomics/Visium to examine the spatial variations between these tumor types. Significantly, our spatial transcriptomic analysis revealed consistent immune-excluded and immune-enriched characteristics compared to traditional RNA sequencing methods. We conducted an analysis of TCGA datasets (The Cancer Genome Atlas) and observed that elevated IRC001 expression is associated with improved prognosis in SKCM (Skin Cutaneous Melanoma). Furthermore, our bioinformatics analysis revealed that melanoma patients exhibiting heightened IRC001 expression displayed positive responses to immune checkpoint blockade therapies. Therefore, we believe that our experimental tumor model can provide vital insights into the cold tumor microenvironment, shaping future therapeutic strategies, and pinpointing molecular candidates that can assist in selecting patients for successful immunotherapy. Citation Format: Yi-Ting Liao, Li-Mei Chen, Wen-Jye Lin. Establishing a screening platform to identify key signaling molecules regulating cold tumor formation through immune evasion and exclusion [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B038.

Abstract A015: Aging limits stemness and tumor development in the lung by reprogramming iron homeostasis

Abstract Aging is the most important and well-recognized risk factor for cancer. Aging leads to systemic decline of physical fitness, significantly changing the macroenvironment from the early tumor initiation to the terminal stage of metastasis. However, the underlying mechanisms only start to emerge. Here, using physiologically aged autochthonous genetically engineered mouse models (GEMMs) and primary cells, we demonstrate that aging suppresses lung cancer initiation and progression by degrading stemness of the alveolar cell of origin. Using single-cell transcriptomics, we uncover a distinct compositional landscape of cancer cell subsets in aged lung tumors, revealing a delay in the molecular progression of the lung lesions and an age-specific gene expression signature. Interestingly, key components of this gene signature were traced back to the aged cell of origin. Furthermore, the age-specific signature derived from GEMMs was predictive of patient age in human lung cancer, indicating conservation of the age-associated changes across species. Interestingly, our preliminary data suggested that tumor cells derived from aged tumor-bearing mice displayed higher metastatic potential, indicating that different mechanisms may govern tumor initiation and metastasis. Functional interrogation of the age-specific gene signature revealed that the loss of stemness and tumorigenic capacity is underpinned by aging-associated induction of the transcription factor NUPR1. We find that NUPR1 is induced in the cell of origin in aged mice and humans, which leads to a functional iron insufficiency in the aged cells. Genetic inactivation of the NUPR1 or iron supplementation restores stemness and promotes tumorigenic potential of aged alveolar cells. Conversely, targeting NUPR1 is detrimental to young alveolar cells by promoting ferroptosis. We find that aging-associated DNA hypomethylation at specific enhancer sites results in elevated NUPR1 expression, which is recapitulated in young cells by inhibition of DNA methylation. We uncover that, unlike the young, aged alveolar cells are functionally iron insufficient, which leads to loss of stemness and resistance to ferroptosis. Our results indicate that aging-associated reprogramming of the cell of origin determines tumor initiation potential, alters trajectory of tumor evolution and produces age-dependent vulnerabilities. These findings demonstrate that aging fundamentally changes the biology of lung cancer, shedding light on novel therapeutic modulation of cellular iron homeostasis or ferroptosis in regenerative medicine and in cancer prevention for the elderly population. Citation Format: Xueqian Zhuang, Qing Wang, Simon Joost, Alexander Ferrena, Melissa Blum, Klavdija Krause, Zhuxuan Li, Deyou Zheng, Emily S Wong, Tuomas Tammela. Aging limits stemness and tumor development in the lung by reprogramming iron homeostasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A015.

Abstract B017: The double-edged sword of cystatin B in luminal-like and triple-negative breast cancers

Abstract The complex protease network of cathepsins and their inhibitors, cystatins, intricately regulates numerous cellular processes, and its dysregulation is frequently implicated in cancer pathogenesis. Abnormal cathepsin activity, subcellular localization, and a disrupted balance between cathepsins and cystatins have been identified in cancer. While diminished cystatin levels typically correlate with more aggressive cancer phenotypes, few findings challenge this paradigm. In this context, our latest study revealed elevated expression of cystatin B (CSTB) in luminal-like breast cancer (BC) patients experiencing relapse within five years post-surgery. Furthermore, computational analysis of publicly available datasets supports our idea of CSTB as a potential negative prognostic biomarker in luminal-like tumors. Intriguingly, a converse relationship is observed in basal-like/triple negative BC patients, where increased CSTB expression seems to be associated with improved prognosis. In addition, the cysteine/cathepsin network intricately intersects with immune functions, adding another layer of complexity. Cathepsins are indeed involved in the induction of an efficient anti-tumor immune response, being key in antigen processing and presentation by antigen-presenting cells and in the cytotoxic activities of NK and T cells. On the other hand, myeloid cells rely on cathepsins for the degradation of ECM proteins that may favor migration and invasion of tumor cells. All these pieces of evidence led to the hypothesis that the functional impact of CSTB may vary depending on the tumor intrinsic characteristics and on its microenvironment and therefore that CSTB might fulfill distinct functional roles in luminal-like and basal-like BC. To start addressing our hypothesis, we silenced CSTB expression in the 4T1 mouse cell line, a TNBC model spontaneously metastasizing to the lungs upon intra-mammary fat pad injection. Preliminary in vivo experiments to investigate the effect on primary tumor growth and metastatic dissemination showed that 4T1 shCSTB lines were indeed characterized by increased tumor growth and metastatic dissemination than the two sh-control lines. Interestingly, expression of stemness- related genes (Nanog, Sox2 and Oct4) were up-modulated upon CTSB silencing, in agreement with a more aggressive phenotype. On the other hand, preliminary in vitro assays with a luminal- like BC cell line support the hypothesis of an opposite effect of CSTB down-modulation in luminal BC subtype. Moreover, CSTB silencing in RAW264.7 macrophagic cell line, impaired M1 in vitro polarization, while it did not appear to affect M2 skewing. Overall, although preliminary, these data suggest that CSTB may affect BC aggressiveness by both interfering with tumor cell-intrinsic features and microenviroment-related traits. Citation Format: Anna Zaccaria, Chiara Ratti, Laura Botti, Sabina Sangaletti, Mario P. Colombo, Claudia Chiodoni. The double-edged sword of cystatin B in luminal-like and triple-negative breast cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B017.

The prognostic implications and oncogenic role of NSUN5 in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC), a predominant form of urinary malignancy, requires the identification of reliable biomarkers to enhance both prognostic outcomes and therapeutic developments specific to ccRCC. NSUN5, a member of the NOL1/NOP2/SUN domain (NSUN) family, plays a critical role in RNA stabilization and exhibits widespread expression across various tumor types. However, the exact function of NSUN5 in ccRCC remains insufficiently understood. Data were collated from cohorts of ccRCC patients who underwent nephrectomy, including those from the Cancer Genome Atlas (TCGA) and the Sun Yat-sen University Cancer Center (SYSUCC), to evaluate the clinical relevance of NSUN5. Integrative models based on NSUN5 expression were subsequently developed to predict the prognosis of ccRCC within the TCGA and SYSUCC cohorts. Furthermore, the impact of NSUN5 on RCC cells and its association with cellular senescence were corroborated through in vitro experimental analyses. NSUN5 exhibited elevated expression in both ccRCC patients and renal cancer cell lines, whose upregulation significantly correlated with age, tumor size, TNM stage, WHO/International Society of Urological Pathology (ISUP) grade, presence of necrosis, and a poor prognosis. An accessible nomogram, incorporating NSUN5 along with various clinicopathological parameters, was adept at predicting outcomes for ccRCC patients. Additionally, in vitro findings indicated that reduced expression of NSUN5 enhanced tumor cell senescence and simultaneously inhibiting cell proliferation and migration. These observations suggest that elevated NSUN5 expression is linked to poorer overall survival (OS) and progression-free survival (PFS), positioning NSUN5 as a viable diagnostic and prognostic biomarker in ccRCC.

Pan-cancer analysis of oncogenic role of CEP55 and experiment validation in clear cell renal cell carcinoma.

Immunotherapy has emerged as a vital component in the contemporary landscape of cancer treatment. Recent studies have indicated that CEP55 plays an oncogenic role; however, its specific mechanisms in promoting tumor proliferation and its potential value in prognosis and immunotherapy prediction across various cancers remain to be elucidated. CEP55 was significantly overexpressed in 22 cancer types compared with their adjacent normal tissues. Elevated CEP55 expression was positively correlated with younger onset age, worse tumor stage, lower response rate to the first treatment, lower tumor-free survival rate, and poorer overall survival (OS) and disease-free survival (DFS) prognosis in most cancers. Moreover, CEP55 expression was positively correlated with its binding and related genes, such as KIF11 (R = 0.83, P < 0.001), CDK1 (R = 0.77, P < 0.001) and CCNA2 (R = 0.76, P < 0.001), and the classic proliferation markers, including MKI67 and PCNA. Enrichment analyses indicated that CEP55 was predominantly associated with cell division, cell cycle activities and proliferation. Immune cell infiltration analysis by TIMER2.0 revealed that CEP55 expression was positively correlated with many kinds of infiltrating cells, such as Th2 cells and some CD4+ T cell subsets. The CEP55 expression was positively associated with increased MSI and TMB in various cancers. Our analyzation indicated that the CEP55 expression level in patients with complete remission (CR) or partial remission (PR) to anti-PDL1 therapy was significantly higher than patients with stable disease (SD) or progressive disease (PD) based on IMvigor210 cohort. We also used Gene Set Cancer Analysis (GSCA) to predict a serious of small molecule CEP55 targeted drugs, such as AZ628, SB52334, SB590885, A-770,041, AZD7762, Elesclomol, panobinostat, BRD-A94377914, and LRRK2-IN-1. Furthermore, the patients with high level of CEP55-posivie tumor epithelial cells had inferior overall survival in ccRCC according to single-cell analysis. Finally, our wet lab experiments verified that the CEP55-positive rate in ccRCC tissues (19/30, 63.3%) was significantly higher than that in renal adjacent tissues (10/30, 33.3%). The clinicopathologic analysis revealed that CEP55 protein level was significantly associated with tumor size (P = 0.044), histology grade (P < 0.001) and stage (P = 0.034). Our study indicated that CEP55 overexpression in most caner types was associated with poor prognosis. Notably, CEP55 was closely relevant to immune cell infiltration and impacted the response to immunotherapy and small molecule drugs against cancers.

SLITRK2 as a prognostic and immunological biomarker in gastric cancer.

SLIT and NTRK-like protein 2 (SLITRK2) encodes a transmembrane protein that regulates neurite outgrowth. Some studies have demonstrated that SLITRK2 overexpressed in glioma. But the expression pattern, prognostic value and immunologic function of SLITRK2 in tumors remains unknown. The expression pattern of SLITRK2 among pan-cancers was examined through the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). We analyzed the association between SLITRK2 expression level and tumor stage among pan-cancers. Kaplan-Meier survival analysis was utilized to investigate the prognostic relevance of SLITRK2 across 33 different types of cancers. Moreover, the correlations among SLITRK2 expression, immune cell infiltration, immunomodulatory related genes, tumor mutation burden (TMB), microsatellite instability (MSI) were evaluated. The relationship between SLITRK2 expression and crucial genes mutations was also illustrated. By using tissue microarray (TMA), the expression of SLITRK2 in 89 paired gastric cancer (GC) tissues was investigated. Our study indicated that SLITRK2 expression varied across cancers. Elevated SLITRK2 expression was positively related to advanced tumor stage, poor overall survival (OS) and reduced disease-free survival (DFS). Bioinformatic analyses underscore SLITRK2's role in immune response, with its expression significantly tied to immune cell infiltration and marker expression. Based on TMA data, SLITRK2 expression level was positively associated with differentiation, lymph node metastasis, AJCC stage, TNM stage, and poor survival outcome in GC patients. Our findings provided that SLITRK2 may function as a biomarker by regulating immune cell infiltration. In addition, we verified that high SLITRK2 expression was correlated with poor prognosis in GC.

Piezo activity levels need to be tightly regulated to maintain normal morphology and function in pericardial nephrocytes.

Due to their position on glomerular capillaries, podocytes are continuously counteracting biomechanical filtration forces. Most therapeutic interventions known to generally slow or prevent the progression of chronic kidney disease appear to lower these biomechanical forces on podocytes, highlighting the critical need to better understand podocyte mechano-signalling pathways. Here we investigated whether the mechanotransducer Piezo is involved in a mechanosensation pathway in Drosophila nephrocytes, the podocyte homologue in the fly. Loss of function analysis in Piezo depleted nephrocytes reveal a severe morphological and functional phenotype. Further, pharmacological activation of endogenous Piezo with Yoda1 causes a significant increase of intracellular Ca++ upon exposure to a mechanical stimulus in nephrocytes, as well as filtration disturbances. Elevated Piezo expression levels also result in a severe nephrocyte phenotype. Interestingly, expression of Piezo which lacks mechanosensitive channel activity, does not result in a severe nephrocyte phenotype, suggesting the observed changes in Piezo wildtype overexpressing cells are caused by the mechanosensitive channel activity. Moreover, blocking Piezo activity using the tarantula toxin GsMTx4 reverses the phenotypes observed in nephrocytes overexpressing Piezo. Taken together, here we provide evidence that Piezo activity levels need to be tightly regulated to maintain normal pericardial nephrocyte morphology and function.

Rotating culture regulates the formation of HepaRG-derived liver organoids via YAP translocation.

Liver organoid serves as an alternative model for liver pathophysiology in carbohydrate or lipid metabolism and xenobiotic metabolism transformation. Biomechanical cues including spaceflight mission can affect liver organoid construction and their related functions, but their underlying mechanisms are not fully understood yet. Here, a rotating cell culture device, namely Rotating Flat Chamber (RFC), was specifically designed for adhering cells or cell aggregated to elucidate the effects of altered gravity vector on HepaRG-derived liver organoids construction. The organoids so formed under RFC presented the fast growth rate and large projection area. Meanwhile, the expressions of two pluripotency markers of SOX9 and CD44 were enhanced. This finding was positively correlated with the increased YAP expression and nuclear translocation as well as the elevated α4β6-integrin expression. Inhibition of YAP expression and nuclear translocation decreased the expression of SOX9 and CD44 under RFC, thereby attenuating the pluripotency of HepaRG-derived liver organoids. In conclusion, we proposed a novel liver organoid construction method using rotating culture, by which the pluripotency of liver organoids so constructed is mediated by α4β6-integrin and YAP translocation. This work furthered the understanding in how the gravity vector orientation affects the construction of liver organoids and the related mechanotransductive pathways.

Integration of Single-Cell and Spatial Transcriptomic Data Reveals Spatial Architecture and Potential Biomarkers in Alzheimer's Disease.

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the gradual loss of neurons and the accumulation of amyloid plaques and neurofibrillary tangles. Despite advancements in the understanding of AD's pathophysiology, the cellular organization and interactions in the prefrontal cortex (PFC) remain elusive. Eight single-cell RNA sequencing (scRNA-seq) datasets from both normal controls and individuals with AD were harmonized. Stringent preprocessing protocols were implemented to uphold dataset integrity. Unsupervised clustering and annotation revealed 22 distinct cell clusters corresponding to 19 unique cell types. The spatial architecture of the PFC region was constructed using the CARD tool. Further analyses encompassed trajectory examination of Oligodendrocyte subtypes, evaluation of regulon activity scores, and spot clustering within white matter regions (WM). Differential expression analysis and functional enrichment assays unveiled molecular signatures linked to AD progression and were validated using microarray data sourced from neurodegenerative disorder patients. Our investigation employs scRNA-seq and spatial transcriptomics to uncover the cellular atlas and spatial architecture of the human PFC in AD. Moreover, our results indicate that Oligodendrocytes are more prevalent in AD patients, showcasing diverse subtypes and spatial organization within WM regions. Each subtype appears to be associated with distinct biological processes and transcriptional regulators, shedding light on their involvement in AD pathology. Notably, the Oligodendrocyte_C6 subtype is linked to neurological damage in AD patients, characterized by heightened expression of genes involved in cell-cell connections, cell membrane stability, and myelination. Additionally, 12 target genes regulated by NFIA were identified, which are upregulated in AD patients and associated with disease progression. Elevated PLXDC2 expression in peripheral blood was also identified, suggesting its potential as a non-invasive biomarker for early AD detection. Our study provides novel insights into the role of Oligodendrocytes in AD and highlights the potential of PLXDC2 as a blood biomarker for non-invasive diagnosis and monitoring of AD patients.

Unveiling the role of Pleckstrin-2 in tumor progression and immune modulation: insights from a comprehensive pan-cancer analysis with focus on lung cancer.

Cancer remains a leading cause of mortality globally, highlighting the need for novel biomarkers to enhance prognosis and therapeutic strategies. Pleckstrin-2 (PLEK2), a member of the pleckstrin family, has been implicated in processes critical to tumor progression, but its role across cancers remains underexplored. This study systematically examined the expression patterns, prognostic relevance, and functional impact of PLEK2 across multiple cancer types. Using data from The Cancer Genome Atlas (TCGA), Genotype Tissue Expression Project (GTEx), and the Human Protein Atlas, we analyzed PLEK2 expression in both cancerous and normal tissues, revealing significant overexpression of PLEK2 in various cancers at the mRNA and protein levels. Single-cell RNA sequencing further indicated predominant expression of PLEK2 in tumor cells and macrophages within the tumor microenvironment. Survival analysis demonstrated that elevated PLEK2 expression correlated with poor prognosis in specific cancers, though its impact varied across cancer types. Functional assays showed that PLEK2 knockdown inhibited proliferation and migration in human cancer cell lines. In vivo studies using a Lewis lung carcinoma (LLC) model confirmed that PLEK2 knockdown suppressed tumor growth and enhanced the efficacy of PD-1 immunotherapy. Mechanistically, PLEK2 knockdown was associated with reduced AKT pathway activation, diminished tumor-associated macrophage infiltration, and increased CD8 T cell presence. Compounds like Navitoclax were also identified as potential PLEK2 inhibitors. In conclusion, PLEK2 played a multifaceted role in cancer progression and immune response modulation. Targeting PLEK2 might suppress tumor growth and overcome immunotherapy resistance, offering a promising biomarker and therapeutic target to improve cancer treatment outcomes.

Drug-resistant BRAF V600E-mutant recurrent pleomorphic xanthoastrocytoma, CNS WHO Grade 3 successfully resolved with incidental discontinuation of combined BRAF and MEK inhibitor therapy

Background: Combination therapy with BRAF and MEK inhibitor holds promise for treating gliomas harboring the BRAF V600E mutation; however, the development of acquired resistance remains a challenge. Case Description: We describe a case of repeated recurrent BRAF-mutant pleomorphic xanthoastrocytoma (central nervous system World Health Organization grade 3) treated with combination therapy with BRAF and MEK inhibitor. The patient received dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor); however, she developed resistance to the combination therapy. Remarkably, incidental drug discontinuation contributed to the disappearance of the resistant tumor. The same phenomenon was repeatedly observed after that. Genetic analysis demonstrated that the resistant tumor had BRAF V600E amplification; the resistant tumor remained BRAF→MEK→ERK pathway dependent, and drug resistance might be due to elevated BRAF V600E expression. We speculated that ERK1/2 signal extremes caused by the discontinuation of the combination therapy affected the resistant tumor survival. Conclusion: This case study provides important insights into novel treatment strategies and their underlying mechanisms for gliomas with BRAF mutations.

Helicobacter pylori promotes gastric cancer progression by activating the TGF-β/Smad2/EMT pathway through HKDC1.

Helicobacter pylori (H. pylori) infection is widely acknowledged as the primary risk factor for gastric cancer, facilitating its progression via the Correa cascade. Concurrently, Hexokinase Domain Containing 1 (HKDC1) has been implicated in the mediation of aerobic glycolysis, contributing to tumorigenesis across various cancers. However, the precise role of HKDC1 in the inflammatory transformation associated with H. pylori-induced gastric cancer remains elusive. In this study, transcriptome sequencing revealed a significant correlation between HKDC1 and H. pylori-induced gastric cancer. Subsequent validation using qRT-PCR, immunohistochemistry, and Western blot analysis confirmed elevated HKDC1 expression in both human and murine gastritis and gastric tumors. Moreover, in vitro and in vivo experiments demonstrated that H. pylori infection up-regulates TGF-β1 and p-Smad2, thereby activating the epithelial-mesenchymal transition (EMT) pathway, with HKDC1 playing a pivotal role. Suppression of HKDC1 expression or pharmacological inhibition of TGF-β1 reversed EMT activation, consequently reducing gastric cancer cell proliferation and metastasis. These results underscore HKDC1's essential contribution to H. pylori-induced gastric cancer progression via EMT activation.

Cirsilineol improves anesthesia/surgery-induced postoperative cognitive dysfunction through attenuating oxidative stress and modulating microglia M1/M2 polarization

Background Cirsilineol is a trimethoxy and dihydroxy flavonoid isolated from plant species such as Artemisia vestita and has a variety of pharmacological properties. This study analyzed whether cirsilineol could prevent postoperative cognitive dysfunction (POCD). Methods A POCD mouse model induced by anesthesia/surgery induction and a cell model established with hydrogen peroxide (H2O2)-induced microglia BV-2 were employed to explore the efficacy of cirsilineol on POCD. The cognition function of the mice were assessed by carrying out behavioral tests (Morris water maze test and Y-maze test). We assessed the activation and polarization status of microglia using immunofluorescence analysis and detected the expression levels of CD86 and CD206 using the quantitative PCR (qPCR). Subsequently, cell viability was determined by CCK-8 assay and apoptosis was assessed using Calcein-AM/PI staining. Meanwhile, superoxide dismutase (SOD) and malondialdehyde (MDA) levels in plasma and cell culture medium were detected using chemiluminescence. Finally, the phosphorylation levels of JAK/STAT signaling pathway-related proteins were analyzed by Western blot. Results Cirsilineol reduced the escape latency and times of crossing island and increased spontaneous alternation (SA) rate, restoring the cognitive dysfunctions of POCD-modeled mice. Meanwhile, POCD elevated CD86 expression and malondialdehyde content and lowered the level of SOD; however, cirsilineol promoted CD206 expression and generation of SOD and inhibited malondialdehyde production. In H2O2-induced microglia BV-2, cirsilineol treatment increased SOD content and suppressed the generation of reactive oxygen species (ROS) and malondialdehyde, modulating microglia M1/M2 polarization and JAK/STAT pathway. Conclusion Cirsilineol prevented against POCD by attenuating oxidative stress and modulating microglia M1/M2 polarization, providing novel insights for the management of POCD.

Prevention of liver metastasis via the pharmacological suppression of AMIGO2 expression in tumor cells.

AMIGO2 adheres to liver endothelium and induces liver metastasis. We revealed that genetically altering AMIGO2 expression in tumor cells affects their liver metastatic potential, depending on the AMIGO2 expression level. The aim of this study was to prevent liver metastasis by pharmacologically suppressing AMIGO2 expression. For screening, we used the mouse LV12 cells because of their affinity to adhere to liver endothelium and metastasize the liver owing to elevated AMIGO2 expression. Of the 285 compounds tested, 17 reduced AMIGO2 mRNA expression. We subsequently screened for compounds that inhibited tumor cell adhesion to liver endothelium and identified five compounds that inhibit three signaling pathways (MEK, JAK, and JNK). Treatment with these compounds inhibited liver metastasis of LV12 cells. Next, we used clinically available signal inhibitors (MEK inhibitor trametinib, JAK inhibitor ruxolitinib, and JNK inhibitor SP600125), and found that ruxolitinib inhibits AMIGO2 expression more stably. Furthermore, ruxolitinib inhibited the adhesion of LV12 cells to liver endothelium and suppressed liver metastasis. Using the MKN45 gastric cancer cells, we confirmed that ruxolitinib could prevent liver metastasis of human cancer cells. These results demonstrate that pharmacological inhibition of AMIGO2 expression in tumor cells is a promising novel strategy to prevent and control liver metastasis.

Characterization of exosome-mediated propagation of systemic inflammatory responses into the central nervous system.

The mechanisms through which systemic inflammation exerts its effect on the central nervous system (CNS) are still not completely understood. Exosomes are small (30 to 100nm) membrane-bound extracellular vesicles released by most of the mammalian cells. Exosomes play a vital role in cell-to-cell communication. This includes regulation of inflammatory responses by shuttling mRNAs, miRNAs, and cytokines, both locally and systemically to the neighboring as well as distant cells to further modulate the transcriptional and/or translational states and affect the functional phenotype of those cells that have taken up these exosomes. The role of circulating blood exosomes leading to neuroinflammation during systemic inflammatory conditions was hereby characterized. Serum-derived exosomes from LPS-challenged mice (SDEL) were freshly isolated from the sera of the mice that were earlier treated with LPS and used to study the effects on neuroinflammation. Exosomes isolated from the sera of the mice injected with saline were used as a control. In-vitro studies showed that the SDEL upregulate pro-inflammatory cytokine gene expression in the murine cell lines of microglia (BV-2), astrocytes (C8-D1A), and cerebral microvascular endothelial cells (bEnd.3). To further study their effects in-vivo, SDEL were intravenously injected into normal adult mice. Elevated mRNA expression of pro-inflammatory cytokines was observed in the brains of SDEL recipient mice. Proteomic analysis of the SDEL confirmed the increased expression of inflammatory cytokines in them. Together, these results demonstrate and strengthen the novel role of peripheral circulating exosomes in causing neuroinflammation during systemic inflammatory conditions.

HIF-1α knockdown attenuates phenotypic transformation and oxidative stress induced by high salt in human aortic vascular smooth muscle cells.

Increased dietary salt intake is a well-established risk factor for hypertension and related cardiovascular diseases, involving complex vascular remodeling processes. However, the specific role of hypoxia-inducible factor-1α (HIF-1α) in vascular pathophysiology under high-salt conditions remains poorly understood. This study investigates the role of HIF-1α in high-salt-induced vascular remodeling using human aortic vascular smooth muscle cells (HA-VSMCs) cultured in vitro. HA-VSMCs were divided into three groups: high-salt with HIF-1α knockdown (shHIF-1α + HS), negative control (shcontrol), and high-salt (HS). Cell viability, migration, gene expression, and protein levels were evaluated. High-salt conditions significantly increased mRNA expression of α-smooth muscle actin (α-SMA), smooth muscle protein 22 (SM22), angiotensin II type 1 receptor (AT1R), collagen I, and collagen III (p < 0.0001). HIF-1α knockdown partially attenuated these increases, particularly for α-SMA, SM22, and AT1R (p < 0.01). At the protein level, high-salt exposure markedly elevated expression of collagen III, HIF-1α, osteopontin (OPN), and angiotensin II (Ang II) (p < 0.0001). HIF-1α knockdown significantly reduced the high-salt-induced increases in collagen III and HIF-1α protein levels (p < 0.001) but had a limited effect on OPN and Ang II upregulation. Interestingly, SM22 protein expression was significantly decreased under high-salt conditions (p < 0.0001), an effect partially reversed by HIF-1α knockdown (p < 0.0001). These findings demonstrate that high-salt conditions induce complex changes in gene and protein expression in HA-VSMCs, with HIF-1α playing a crucial role in mediating many of these alterations. The study highlights the differential effects of HIF-1α on various markers of vascular remodeling and suggests that HIF-1α may be a potential therapeutic target for mitigating salt-induced vascular pathology. Further research is warranted to elucidate the mechanisms underlying the HIF-1α-dependent and -independent effects observed in this study.