Biological Behavior Of Tumor Research Articles

Contribution of Cancer-Specific Protein Coronas to the Pro-Tumor Effects of Nanoplastics through Enhanced Cellular Interactions.

The potential impact of nanoplastics (NPs) on human carcinogenic processes is a matter of growing concern, particularly in light of the global plastic pollution crisis. Although the potential effects of NPs on human health have been well investigated, many uncertainties remain regarding their role in tumor behavior. Upon exposure, NPs can enter the bloodstream and are prone to interacting with plasma proteins to form a protein corona (PC), which can influence their interactions with cancer cells. However, how the PCs adsorbed on NPs affect the particle-to-tumor cell interaction and their effect on the tumor biological behavior remain unclear. To better understand the formation of PCs following NPs exposure in the bloodstream under various clinical conditions, we investigated the PC compositions of NPs derived from thyroid cancer (TC) patients and healthy volunteers. Our data revealed a significant enrichment of fibrinogen in the PCs formed on NPs derived from TC patient plasma, which in turn accelerated the endocytosis of NPs into TC cells. In addition, the uptake pathway of NPs into TC cells differed substantially between the two groups studied due to the different PC compositions in cancer patients and healthy individuals. Moreover, intriguingly alterations in the PCs induced by the clinical pathology status were also found to promote NPs engulfment by human macrophages, resulting in potent pro-inflammatory effects, in turn exerting pro-tumor effects. These findings emphasize the importance of considering the significance of a realistic biological identity on NPs and their interactions with cancer cells and also pinpoint the implications of the carcinogenesis outcomes of NPs exposure in humans.

Role of Advanced Magnetic Resonance Imaging in Differentiating among Glioma Subtypes and Predicting Tumor-Proliferative Behavior

Abstract Objective Gliomas are a devastating and heterogeneous group of primary brain tumors. Previously, the source of glioma was undetermined. Recent literature indicates that neural stem cells, or progenitors, are proposed to be the source of glioma. The prognosis of different types of gliomas differs due to their various biological tissue types. Besides the histological grade, the two useful immunohistochemistry markers that show the tumor's biological behavior are isocitrate dehydrogenase (IDH) labeling and the Ki-67 labeling index. We sought to determine the magnetic resonance imaging (MRI) characteristics associated with IDH mutational status and ascertain whether MRI combined with IDH mutational status, can better predict the clinical outcomes of gliomas. Materials and Methods This period study was conducted in the Department of Radiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India for 5 years (May 2016–May 2021). The study cohort included 30 patients diagnosed with gliomas who underwent preoperative MRI followed by surgical resection and histopathological examination. Preoperative MRI images were done to assess qualitative tumor characteristics such as location, margin of tumor, extent, cortical involvement, cystic component, mineralization or hemorrhage, and contrast enhancement. Discussion Differences in MRI features between IDH-mutant (MT) and IDH-wild-type (WT) groups were analyzed using the chi-square test for categorical variables and the Mann–Whitney U test for continuous variables. Statistical analysis was conducted using SPSS software. Results Among the 30 patients evaluated, 18 had IDH-WT and 12 had IDH-MT type gliomas. Male predominance (73.33%) was noted in our study. Brainstem location, indistinct borders (83.33%), less cortical involvement (72.22%), less cystic changes (88.89%), more area of necrotic component (44.44%), significantly increased choline/creatine (Cho/Cr) ratio, and choline/N-acetyl aspartate (Cho/NAA) ratio favors IDH-WT tumors. Positive T2-fluid-attenuated inversion recovery mismatch sign is more frequently seen in IDH-MT (7/12; 58.33%) tumors than in IDH-WT (4/18; 22.22%) tumors. Whereas well-defined contours (66.67%), more cortical involvement (83.33%), more cystic changes (58.33%), and less area of necrotic component favor IDH-MT type tumors. Conclusion MRI is a very promising and valuable tool for differentiating among glioma subtypes and predicting tumor-proliferative behavior in glioma cases. The combination of MRI characteristics with IDH mutation status enhances the predictive accuracy for clinical outcomes in glioma patients. This approach could potentially guide treatment planning and improve prognostic assessments.

The role of short-chain fatty acid metabolism in the pathogenesis, diagnosis and treatment of cancer.

Short-chain fatty acids (SCFAs), which are saturated fatty acids consisting of six or fewer carbon atoms, have been found to be closely associated with the biological behavior of malignant tumors. This manuscript provides a comprehensive review on the role of SCFAs in regulating cell cycle, apoptosis, tumor angiogenesis, epithelial-mesenchymal transition, protein regulatory pathways, and histone regulation in promoting the development of malignant tumors. Furthermore, we discuss the potential therapeutic strategies targeting SCFAs for treating malignant tumors. This review offers a theoretical foundation for investigating the mechanisms by which SCFAs impact malignant tumors and provides insights into developing novel treatment targets.

MiR-155-5p regulates autophagy and apoptosis of glioma cells through RICTOR.

Glioma characterized by the high degree of drug resistance and the poor prognosis is the most common primary malignant tumors of the brain. And miRNA is involved in a variety of biological behaviors of tumors, enhancing or inhibiting the occurrence and development of tumors. Therefore, the present study aims to explore whether miR-155-5p can regulate autophagy and apoptosis of glioma through RICTOR. The significantly differential gene miR-155-5p was identified from the Gene Expression Omnibus (GEO; http://www.ncbi.nlm.nih.gov/geo) databases GSE165937 and GSE138764 using bioinformatics analysis, and its expression was validated by quantitative real-time polymerase chain reaction (qRT-PCR). The putative target genes of miR-155-5p were predicted through interrogation of relevant databases, followed by identification of key target genes. Subsequently, core target genes were selected for functional enrichment analysis. The U87MG cell line was utilized as the experimental model and divided into Negative Control1 (NC1) group, Mimic group, Negative Control2 (NC2) group, Inhibitor group, and NC + 3-methyladenine (3-MA) group. The expression levels of miR-155-5p, RICTOR, P62, LC-3, Bax, Bcl-2, and Caspase-3 were assessed using qRT-PCR, cellular fluorescence imaging, and Western blotting; while apoptosis in the U87MG cell line was evaluated via flow cytometry. The results showed that miR-155-5P was highly expressed in glioma cells, which could inhibit the expression of Bax, Caspase-3, LCII/LCI and Beclin-1, and increase the expression of Bcl2 and P62. Flow cytometry and cell fluorescence were used to verify the above results. Moreover, when U87MG cells treated with miR-155-5p inhibitor were inhibited by 3-MA, the results showed that miR-155-5p enhanced the anti-apoptotic ability of U87MG cells by regulating autophagy. In addition, the bioinformatics results show that miR-155-5p survival prognosis in glioma into a strong negative correlation, while the survival prognosis of RICTOR in glioma showed a strong positive correlation. The core target genes Kyoto Encyclopedia of Genes and Genomes (KEGG) mainly occurred in PI3K-AKT signaling pathway; in addition, qRT-PCR and Western blot confirmed the regulatory effect of miR-155-5P on RICTOR. MiR-155-5p regulates autophagy and apoptosis-related proteins in glioma cells through RICTOR, affecting the occurrence and development of glioma.

The MCIB Model: A Novel Theory for Describing the Spatial Heterogeneity of the Tumor Microenvironment

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.

Surgical Treatment of Primary Mast Cell Tumor in Mucosal Surface of Lower Lip in a Dog: A Case Report

Introduction: Mast cell tumors (MCTs) have been described as a form of cancer affecting a specific type of blood cell that typically plays a role in the body's reaction to allergens and inflammatory processes. The MCTs have been classified as skin tumors in dogs which can also affect other areas of the body, such as the spleen, liver, gastrointestinal tract, and bone marrow. The present study investigated the clinical and histological signs, biological behavior, and treatment of primary oral mast cell tumors. Case report: A 3-year-old neutered female, weighing 18 kg and classified as a medium mixed breed, was referred to a veterinary clinic in Mashhad (Iran) due to the presence of a pink, lobulated mucosal mass located on the internal surface of her lower lip. Although the vital signs were normal, clinical examination, radiology, and an incisional biopsy were performed from the lesion site under general anesthesia for histology study. Histopathological features were similar to those of mastocytoma in this case. On presentation, no concurrent mass was found on other sides of the body. Mandibular lymph nodes were not enlarged; however, the incisor teeth of the mandible were loosed. Accordingly, the primary oral MCTs were diagnosed. The surgery was done and After a follow-up period of 150 days post-excisional surgery for a Mast cell tumor, the patient remained alive and exhibited no visible signs of tumor recurrence or surgical complications. Conclusion: The current case report defined a primary Mast cell tumor with slow tumor growth and without metastasis in the mucosal surface of the lower lip in a dog treated by complete excisional surgery only, unlike some previous studies of primary oral MCTs in dogs with aggressive biological behaviors.

Progress of Cancer Stem Cells in Retinoblastoma.

The theory of cancer stem cells is a breakthrough discovery that offers exciting possibilities for comprehending the biological behavior of tumors. More and more evidence suggests that retinoblastoma cancer stem cells promote tumor growth and are likely to be the origin of tumor formation, drug resistance, recurrence, and metastasis. At present, some progress has been made in the verification, biological behavior, and drug resistance mechanism of retinoblastoma cancer stem cells. This article aims to review the relevant research and explore future development direction.

CT-based radiomic consensus clustering association with tumor biological behavior in clinical stage IA adenocarcinoma: a retrospective study.

Research has demonstrated that radiomics models are capable of forecasting the characteristics of lung cancer. Nevertheless, due to radiomics' poor interpretability, its applicability in clinical settings remains restricted. This investigation sought to verify the correlation between radiomics features (RFs) and the biological behavior of clinical stage IA adenocarcinomas. A retrospective analysis was conducted on patients diagnosed with clinical stage IA lung adenocarcinoma who underwent resection between May 2005 and December 2018. Detailed radiomics examination of the primary tumor was carried out utilizing preoperative computed tomography (CT) images. Subsequently, patients were grouped based on their RFs using consensus clustering, enabling comparison of tumor biological characteristics among the clusters. Survival disparities among the clusters were evaluated through Kaplan-Meier and Cox analyses. A consensus cluster analysis was performed on 669 patients [median age, 58 years; interquartile range (IQR), 50-64 years, 257 males, 412 females], and three distinct clusters were identified. Cluster 2 was associated with radiological solid adenocarcinoma [119 of 324 (36.7%), P<0.001], larger tumors with median tumor size of 2.1 cm with IQR of 1.7 to 2.5 cm (P<0.001), central tumor [91 of 324 (28.1%), P=0.002], pleural invasion [87 of 324 (26.9%), P<0.001], occult lymph node metastasis (ONM) [106 of 324 (32.7%), P<0.001], and a higher frequency of metastasis or recurrence [62 of 324 (19.1%), P<0.001]. The frequency of histological grade 3 was the highest in Cluster 3 [8 of 34 (23.5%), P<0.001]. Cluster 1 was associated with pure ground glass nodules (pGGNs) [184 of 310 (59.4%), P<0.001], smaller tumors with median tumor size of 1.1 cm with IQR of 0.8 to 1.4 cm (P<0.001), no pleural invasion [276 of 310 (89.0%), P<0.001], histological grade 1 [114 of 248 (46.0%), P<0.001], ONM negative [292 of 310 (94.2%), P<0.001], and a lower rate of metastasis or recurrence [298 of 310 (96.1%), P<0.001]. Differences in tumor biological behavior were detected among consensus clusters based on the RFs of clinical stage IA adenocarcinoma.

Identification and experimental verification of a biomarker by combining the unfolded protein response with the immune cells in colon cancer.

The unfolded protein response (UPR) is associated with immune cells that regulate the biological behavior of tumors. This article aims to combine UPR-associated genes with immune cells to find a prognostic marker and to verify its connection to the UPR. Univariate cox analysis was used to screen prognostically relevant UPRs and further screened for key UPRs among them by machine learning. ssGSEA was used to calculate immune cell abundance. Univariate cox analysis was used to screen for prognostically relevant immune cells. Multivariate cox analysis was used to calculate UPR_score and Tumor Immune Microenvironment score (TIME_score). WGCNA was used to screen UPR-Immune-related (UI-related) genes. Consensus clustering analysis was used to classify patients into molecular subtype. Based on the UI-related genes, we classified colon adenocarcinoma (COAD) samples by cluster analysis. Single-cell analysis was used to analyze the role of UI-related genes. We detected the function of TIMP1 by cell counting and transwell. Immunoblotting was used to detect whether TIMP1 was regulated by key UPR genes. Combined UPR-related genes and immune cells can determine the prognosis of COAD patients. Cluster analysis showed that UI-related genes were associated with clinical features of COAD. Single-cell analysis revealed that UI-related genes may act through stromal cells. We defined three key UI-related genes by machine learning algorithms. Finally, we found that TIMP1, regulated by key genes of UPR, promoted colon cancer proliferation and metastasis. We found that TIMP1 was a prognostic marker and experimentally confirmed that TIMP1 was regulated by key genes of UPR.

Circ-CDK8 regulates SLC7A11-mediated ferroptosis by inhibiting miR-615-5p to promote progression in oral squamous cell carcinomas.

Introduction: Ferroptosis is a new mode of programmed cell death distinct from necrosis, apoptosis, and autophagy, induced by iron-ion-dependent lipid peroxide accumulation. Circular RNAs are a class of endogenous non-coding RNAs that regulate the biological behavior of tumors. However, the role of circ-CDK8 in regulating ferroptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) remains unknown. Methods: The effect of circ-CDK8 on OSCC cell ferroptosis, migration, and invasion was evaluated using CCK-8, wound healing, transwell, reactive oxygen species (ROS), malondialdehyde (MDA), and GSH assays and Western blotting. Bioinformatics analyses and luciferase reporter assays were performed and revealed targeted relationships between circ-CDK8 and miR-615-5p, miR-615-5p and SLC7A11. Interference with circ-CDK8 expression reduced SLC7A11 expression by sponging miR-615-5p, suppressed OSCC cell migration and invasion, and promoted ferroptosis by increasing ROS, MDA, and iron levels and decreasing GSH and GPX4 levels in OSCC cells. Furthermore, in vivo, animal experiments confirmed that circ-CDK8 interference inhibited OSCC cell proliferation and SLC7A11 expression. Results: Collectively, this study revealed a novel strategy to upregulate erastin-induced ferroptosis in OSCC cells via the circ-CDK8/miR-615-5p/SLC7A11 axis, providing new insights into OSCC and a potential therapeutic strategy for OSCC.

Unveiling the multifaceted roles of microRNAs in extracellular vesicles derived from mesenchymal stem cells: implications in tumor progression and therapeutic interventions.

Mesenchymal stem/stromal cells (MSCs) have the capacity to migrate to tumor sites in vivo and transmit paracrine signals by secreting extracellular vesicles (EVs) to regulate tumor biological behaviors. MSC-derived EVs (MSC-EVs) have similar tumor tropism and pro- or anti-tumorigenesis as their parental cells and exhibit superior properties in drug delivery. MSC-EVs can transfer microRNAs (miRNAs) to tumor cells, thereby manipulating multiple key cancer-related pathways, and further playing a vital role in the tumor growth, metastasis, drug resistance and other aspects. In addition, tumor cells can also influence the behaviors of MSCs in the tumor microenvironment (TME), orchestrating this regulatory process via miRNAs in EVs (EV-miRNAs). Clarifying the specific mechanism by which MSC-derived EV-miRNAs regulate tumor progression, as well as investigating the roles of EV-miRNAs in the TME will contribute to their applications in tumor pharmacotherapy. This article mainly reviews the multifaceted roles and mechanism of miRNAs in MSC-EVs affecting tumor progression, the crosstalk between MSCs and tumor cells caused by EV-miRNAs in the TME. Eventually, the clinical applications of miRNAs in MSC-EVs in tumor therapeutics are illustrated.

Construction and validation of a prognostic model for overall survival time of patients with ovarian cancer by metabolism-related genes.

Ovarian cancer is a female-specific malignancy with high morbidity and mortality. The metabolic reprogramming of tumor cells is closely related to the biological behavior of tumors. The prognostic signature of the metabolism-related gene (MRGs) was established by LASSO-Cox regression analysis. The prognostic signature of MRGs was also prognosticated in each clinical subgroup. These genes were subjected to functional enrichment analysis and tissue expression exploration. Analysis of the MRG prognostic signature in terms of immune cell infiltration and antitumor drug susceptibility was also performed. A MRG prognostic signature including 21 genes was established and validated. Most of the 21 MRGs were expressed at different levels in ovarian cancer than in normal ovarian tissue. The enrichment analysis suggested that MRGs were involved in lipid metabolism, membrane organization, and molecular binding. The MRG prognostic signature demonstrated the predictive value of overall survival time in various clinical subgroups. The monocyte, NKT, Tgd and Tex cell scores showed differences between the groups with high- and low-risk score. The antineoplastic drug analysis we performed provided information on ovarian cancer drug therapy and drug resistance. In vitro experiments verified that PLCH1 in 21 MRGs can regulate the apoptosis and proliferation of ovarian cancer cells. This metabolism-related prognostic signature was a potential prognostic factor in patients with ovarian cancer, demonstrating high stability and accuracy.

A Comprehensive Review on the Role of MRI in the Assessment of Supratentorial Neoplasms: Comparative Insights Into Adult and Pediatric Cases.

Magnetic resonance imaging (MRI) is a critical diagnostic tool in assessing supratentorial neoplasms, offering unparalleled detail and specificity in brain imaging. Supratentorial neoplasms in the cerebral hemispheres, basal ganglia, thalamus, and other structures above the tentorium cerebelli present significant diagnostic and therapeutic challenges. These challenges vary notably between adult and pediatric populations due to differences in tumor types, biological behavior, and patient management strategies. This comprehensive review explores the role of MRI in diagnosing, planning treatment, monitoring response, and detecting recurrence in supratentorial neoplasms, providing comparative insights into adult and pediatric cases. The review begins with an overview of the epidemiology and pathophysiology of these tumors in different age groups, followed by a detailed examination of standard and advanced MRI techniques, including diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), and magnetic resonance spectroscopy (MRS). We discuss the specific imaging characteristics of various neoplasms and the importance of tailored approaches to optimize diagnostic accuracy and therapeutic efficacy. The review also addresses the technical and interpretative challenges unique to pediatric imaging and the implications for long-term patient outcomes. By highlighting the comparative utility of MRI in adult and pediatric cases, this review aims to enhance the understanding of its pivotal role in managing supratentorial neoplasms. It underscores the necessity of age-specific diagnostic and therapeutic strategies. Emerging MRI technologies and future research directions are also discussed, emphasizing the potential for advancements in personalized imaging approaches and improved patient care across all age groups.

Silencing CK19 regulates ferroptosis by affecting the expression of GPX4 and ACSL4 in oral squamous cell carcinoma in vivo and in vitro

To analyze the mechanism of how interfering with the cytokeratin 19 (CK19) pathway via the ferroptosis pathway affects tumor biological behaviors in the process of oral squamous cell carcinoma (OSCC) development. TCGA was used to analyze the expression of CK19 in pan-cancer and head and neck squamous cell carcinoma (HNSC) and to explore the ferroptosis-related genes related to HNSC. The effect of silencing CK19 on the migration ability of HSC-4 cells was verified by wound healing and migration assay. HSC-4 cells with silencing of CK19 and tumor-bearing nude mouse model were constructed. RT-qPCR, immunofluorescence and western blot were used to analyze the expression of ferroptosis-related genes. CK19 is highly expressed in human OSCC and nude mice. The migration ability of cells in the CK19-silenced group was lower than that of the control group. In vivo and in vitro, CK19 was negatively correlated with the expression of ACSL4 and positively correlated with the expression of GPX4. Compared with the control group, GPX4 expression was down-regulated and ACSL4 expression was up-regulated in the CK19-silenced group. Silencing CK19 also increased intracellular Fe2+ content and MDA content. Silencing CK19 can affect the expression of GPX4 and ACSL4 to regulate ferroptosis and at the same time increase the content of MDA, Fe2+ and ROS levels, thereby activating the regulation of ferroptosis pathway in the development of OSCC.

Single-Cell Transcriptome Analysis Reveals 2 Subtypes of Tumor Cells of Sclerosing Pneumocytoma With Distinct Molecular Features and Clinical Implications

Pulmonary sclerosing pneumocytoma (PSP) is a rare, distinctive benign lung adenoma of pneumocyte origin. Despite its rarity, the tumor’s unique cellular morphology has sparked ongoing debates regarding the origin of its constituent cells. This study aimed to elucidate the molecular features of PSP tumor cells and enhance our understanding of the cellular processes contributing to PSP formation and biological behavior. Tissue samples from PSP and corresponding normal lung tissues (n = 4) were collected. We employed single-cell RNA sequencing and microarray-based spatial transcriptomic analyses to identify cell types and investigate their transcriptomes, with a focus on transcription factors, enriched gene expression, and single-cell trajectory evaluations. Our analysis identified 2 types of tumor cells: mesenchymal-epithelial dual-phenotype (MEDP) cells and a distinct subpopulation of type II alveolar epithelial cells exhibiting characteristics slightly reminiscent of type I alveolar epithelial cells (AT2Cs) corresponding to histologic round stromal cells and surface cuboidal cells, respectively. MEDP cells displayed weak alveolar epithelial differentiation but strong collagen production capabilities, as indicated by the expression of both TTF-1 and vimentin. These cells played a pivotal role in forming the solid and sclerotic areas of PSP. Moreover, MEDP cells exhibited a pronounced propensity for epithelial-mesenchymal transition, suggesting a greater potential for metastasis compared with AT2Cs. The capillary endothelial cells of PSP displayed notable diversity. Overall, this study provides, for the first time, a comprehensive mapping of the single-cell transcriptome profile of PSP. Our findings delineate 2 distinct subtypes of tumor cells, MEDP cells and AT2Cs, each with its own biological characteristics and spatial distribution. A deeper understanding of these cell types promises insights into the histology and biological behaviors of this rare tumor.

TMB Signature-Related RCAN2 Promotes Apoptosis by Upregulating EHF/DR5 Pathway in Hepatocellular Carcinoma.

The tumour mutation burden (TMB) is a valuable indicator of the accumulation of somatic mutations, and is thought to be associated with the biological behaviour and prognosis of tumours. However, the related genetic mechanism for these association is still unclear. The aim of the present study was to identify the key gene(s) associated with TMB in hepatocellular carcinoma (HCC) and to investigate its biological functions, downstream transcription factors, and mechanism of action. Patients in The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) database were classified according to TMB signature-related genes. Key genes related to the TMB signature and tumour prognosis were identified. Immunohistochemistry and Quantitative Real-Time Polymerase Chain Reaction (qPCR) were then used to assess gene expression in clinical HCC tissues and HCC cells. Cells with altered gene expression were evaluated for the effect on cell proliferation and apoptosis, both in vitro and in vivo. Three independent databases and cell sequencing data were used to identify the mechanisms involved and the downstream transcription factors. The mechanism was also studied by altering the expression of downstream transcription factors in vitro. The integrated cluster (IC) 2 group, characterized by 99 TMB signature-related genes, showed a significant different TMB score compared to the IC1 group (p < 0.001), as well as more favourable tumour prognosis (p = 0.031). We identified five key prognostic genes that were differentially expressed between IC2 and IC1 and were associated with overall survival. The expression of one of these key prognostic genes, RCAN2, was negatively correlated with TMB in 18 out of 33 tumour types examined. A high level of RCAN2 was correlated with better overall survival in HCC (p = 0.0009). Overexpression of RCAN2 enhanced apoptosis in vitro and in vivo, whereas knockdown of RCAN2 attenuated apoptosis. The mechanism by which RCAN2 promotes apoptosis may involve upregulation of the expression of ETS homologous factor (EHF) and of death receptor 5 (DR5). Downregulation of RCAN2 expression was found to correlate with elevated TMB in multiple cancer types. RCAN2 was also found to be a biomarker of HCC prognosis, and to promote the apoptosis of HCC cells through the EHF/DR5 pathway. These findings provide a new perspective on systemic treatment for advanced HCC with a high TMB.

Mucin 1 expression is regulated by hsa_circ_0055054/microRNA‑122‑5p and promotes hepatocellular carcinoma development.

The abnormal expression of mucin 1 (MUC1) is a major cause of poor prognosis in patients with hepatocellular carcinoma (HCC). Competitive endogenous RNA demonstrates a novel regulatory mechanism that can affect the biological behavior of tumors. In the present study, the regulatory functions of hsa_circ_0055054 as well as those of microRNA (miR/miRNA) 122-5p on MUC1 expression and its role in HCC cell proliferation, migration and invasion, were evaluated. MUC1 expression was assessed using western blotting and reverse transcription-quantitative PCR. The phenotypic functions of the HCC cell lines were evaluated following MUC1 knockdown using Cell Counting Kit-8, wound healing and Transwell assays. Bioinformatics tools were used to identify specific miRNAs and circular (circ)RNAs that interact with and can regulate MUC1. The stability of circRNAs was assessed using a Ribonuclease R assay. The binding of circRNA/miRNA/MUC1 was assessed using dual-luciferase reporter assays and cellular function tests. Finally, in vivo experiments were performed using animal models. The results demonstrated that in MHCC97L cells, MUC1 and hsa_circ_0055054 were expressed at high levels while miR-122-5p was downregulated. The proliferation, migration and invasion of MHCC97L cells were suppressed by low MUC1 expression. hsa_circ_0055054 knockdown or miR-122-5p overexpression both led to a decrease in MUC1 expression. In MHCC97L cells with a low MUC1 expression caused by hsa_circ_0055054 knockdown, miR-122-5p inhibition resulted in the increased proliferation, migration and invasion of MHCC97L cells. In combination, the results of the present study indicate that hsa_circ_0055054 knockdown in MHCC97L cells leads to an increased expression of miR-122-5p and decreased expression of MUC1, which results in the inhibition of MHCC97L cell proliferation, migration and invasion.

MDB-94. RADIOMICS-BASED DECISION SUPPORT FOR PEDIATRIC MEDULLOBLASTOMA RISK STRATIFICATION ON MULTI-PARAMETRIC MRI

Abstract BACKGROUND Medulloblastoma (MB) is the most common pediatric brain malignancy. Accurate risk stratification is crucial for prescribing appropriate therapy. However, current risk stratification into standard or high-risk groups is limited in scope and does not accurately address the unique biological behavior of each specific tumor, with approximately 30% of children diagnosed with MB suffering from treatment failure. We developed a radiomic tool to more accurately risk stratify children with MB. METHODS We collected 1.5T/3T MRI (Siemens, Philips, or GE scanners) and clinical data from 80 patients with MB treated at Children’s Healthcare of Atlanta. Radiomic features that quantify textural heterogeneity including first and second order statistics, Haralick’s features from Gray Level Co-occurrence Matrices, and CoLIAge were extracted from tumor volumes segmented by a board-certified radiologist from multi-parametric MRI data including Apparent Diffusion Coefficient (ADC), T2, and post-contrast T1 sequences. Continuous survival models were built using the Cox proportional hazard method with 70% of the data for progression free survival (PFS) and overall survival (OS) using the 5 most predictive features obtained by univariate analysis after removing correlated features within the training data. RESULTS We developed three models with T1, T2, and ADC separately to evaluate predictive power of radiomic signatures. Three models for predicting MB OS delivered Harrel’s concordance indices (C-index) of 0.72 and 0.61 (T1); 0.70 and 0.65 (T2); and 0.80 and 0.76 (ADC) for training and test, respectively. C-indices for PFS were 0.70 and 0.69 (T1); 0.73 and 0.67 (T2); and 0.63 and 0.61 (ADC). CONCLUSIONS Our preliminary results show the feasibility and efficacy of our approach for predicting MB OS and PFS. Future studies will build an integrated model combining T1,T2, ADC, and other clinical information for predicting MB OS and PFS using a large multi-center validation cohort.

CircVCAN promotes glioma progression through the miR-488-3p/MEF2C-JAGGED1 axis.

Gliomas are the most prevalent primary malignant brain tumors worldwide. Growing evidences indicate that circular RNAs (circRNAs) play an important role in the regulation of biological behavior of tumors. We aimed to investigate the role and mechanism of circVCAN in glioma. RNase R treatment was utilized to assess the cyclic properties of circVCAN. CircVCAN, miR-488-3p, and myocyte enhancer factor 2C (MEF2C) levels in glioma tissues and cells were detected by reverse transcription real-time polymerase chain reaction (RT-qPCR), and the localization of them in glioma cells was determined with fluorescence in situ hybridization. Furthermore, a variety of biologically functional assessments were used to validate the role of circVCAN in glioma. The regulatory mechanisms of circVCAN, miR-488-3p, and MEF2C were further confirmed by double luciferase reporter gene assay, RNA immunoprecipitation and RNA pull-down assay, and the binding of MEF2C to JAGGED1 was revealed by chromatin immunoprecipitation. Additionally, a xenograft tumor model was constructed to demonstrate the effect of circVCAN on tumor growth in vivo. Our results indicated that circVCAN was more stable than its linear RNA and was significantly upregulated in gliomas. CircVCAN overexpression stimulated glioma cells to proliferate and metastasize, but circVCAN silencing exerted the opposite effect. Meanwhile, silencing circVCAN inhibited tumor growth in vivo. Moreover, we found that circVCAN interacted with miR-488-3p to regulate MEF2C expression, and miR-488-3p inhibition or MEF2C overexpression reversed the inhibitory effect on malignant bio-behaviors mediated by circVCAN knockdown in glioma cells. MEF2C promoted the transcription of JAGGED1, and circVCAN knockdown reduced the binding between MEF2C and JAGGED1. Collectively, circVCAN is a carcinogenic circRNA in glioma, and the circVCAN/miR-488-3p/MEF2C-JAGGED1 axis could serve as a potential target for the management of glioma.

Clinical and epidemiological profile of patients with atypical melanomas treated with immunotherapy.

e21532 Background: Atypical melanomas, such as acral lentiginous, uveal, mucosal, spitzoid, desmoplastic, meningeal, and primary occult site, represent less than 5% of melanoma cases. Due to their different biological tumor behavior from cutaneous melanomas, their treatment is still challenging. Currently, checkpoint inhibitors are the main treatment based on extrapolations or data from small surveys. Methods: This study aims to describe the epidemiological profile, clinical and pathological characteristics, and treatment of patients with atypical melanomas treated with immunotherapy. It is an observational, descriptive, retrospective study that analyzed 72 medical records of patients with atypical melanomas, ECOG 0-1, &gt; 18 years old, treated with immunotherapy (neo, adjuvant, and palliative lines), between January 2015 and December 2023 at the A.C. Camargo Cancer Center, São Paulo, Brazil. Results: We gathered 72 patients, 61% male and 39% female, with an average age of 58.89 (±13.63) years; 57% were white, 15% African-descendant (black and brown), 8% Asian, and 20% not specified. Regarding primary site, 26% were acral, 24% mucosal, 24% occult primary site, 15% uveal, 8% desmoplastic, 1% amelanocytic, 1% spitzoid, and 1% cauda equina meningeal. Regarding staging, (3%) were stage I, (15%) stage II, (25%) stage III, (47%) stage IV, and (10%) unknown. LDH: 372.5 (±360) mg/dL. Metastases: lymph node 29%; hepatic 23%; pulmonary 21%; bone 18%; central nervous system 15%; peritoneal carcinomatosis 5%; stomach 3%; cauda equina 3%; adrenal 1%; in transit 1%; intestine 1%; bone marrow 1%; parotid 1%. BRAF mutations were present in 23% of cases (variants V660E, V600K, V660R, and G469R); NRAS 6% (codons 13 and 61); KIT 1% (exon 11) and NTRAK 1% (S701F). In relation to treatment, 5 received neoadjuvant anti-pd1 + anti-ctla4 combination, 13 adjuvant with anti-pd1+/- anti-ctla4. About 50 patients received systemic treatment for metastatic disease anti-pd1+/- anti-ctla4. Overall survival: 26 (±14.8) months. Conclusions: Atypical melanoma primary occult site is the most prevalent, with the majority diagnosed at stage IV, with high LDH levels and lymph nodes as the main sites of metastases. Twenty-three percent had a BRAF gene mutation. The majority were treated palliatively with first-line immunotherapy, with median survivals of 14.8 months.