Tumor Microenvironment Research Articles

Identification of immune-associated genes for the diagnosis of ulcerative colitis-associated carcinogenesis via integrated bioinformatics analysis

BackgroundUC patients suffer more from colorectal cancer (CRC) than the general population, which increases with disease duration. Early colonoscopy is difficult because ulcerative colitis-associated colorectal cancer (UCAC) lesions are flat and multifocal. Our study aimed to identify promising UCAC biomarkers that are complementary endoscopy strategies in the early stages.MethodsThe datasets may be accessed from the Gene Expression Omnibus and The Cancer Genome Atlas databases. The co-expressed modules of UC and CRC were determined via weighted co-expression network analysis (WGCNA). The biological mechanisms of the shared genes were exported for analysis using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. To identify protein interactions and hub genes, a protein-protein interaction network and CytoHubba analysis were conducted. To evaluate gene expression, external datasets and experimental validation of human colon tissues were utilized. The diagnostic value of core genes was examined through receiver operating characteristic (ROC) curves. Immune infiltration analysis was employed to investigate the associations between immune cell populations and hub genes.ResultsThree crucial modules were identified from the WGCNA of UC and CRC tissues, and 33 coexpressed genes that were predominantly enriched in the NF-κB pathway were identified. Two biomarkers (CXCL1 and BCL6) were identified via Cytoscape and validated in external datasets and human colon tissues. CRC patients expressed CXCL1 at the highest level, whereas UC and CRC patients showed higher levels than the controls. The UC cohort expressed BCL6 at the highest level, whereas the UC and CRC cohorts expressed it more highly than the controls. The hub genes exhibited significant diagnostic potential (ROC curve > 0.7). The immune infiltration results revealed a correlation among the hub genes and macrophages, neutrophils and B cells.ConclusionsThe findings of our research suggest that BCL6 and CXCL1 could serve as effective biomarkers for UCAC surveillance. Additionally, they demonstrated a robust correlation with immune cell populations within the CRC tumour microenvironment (TME). Our findings provide a valuable insight about diagnosis and therapy of UCAC.

CAF Specific Expression of Podoplanin May Be Dispensable for the Malignancy of Malignant Melanoma

ABSTRACTWithin the tumor microenvironment (TME), cancer‐associated fibroblasts (CAFs) were shown to be an active and pivotal cell population, supporting many protumorigenic mechanisms. Podoplanin (PDPN)‐positive CAFs are of special interest since their abundance correlated with a worse prognosis for patients of different cancer entities, including malignant melanoma. In this study, we applied a loss‐of‐function approach in an in vivo mouse melanoma model to evaluate the contribution of CAF‐specific PDPN expression to melanoma formation and progression. Surprisingly, despite its prominent expression in CAFs deletion of PDPN in this cell type did neither affect the onset, nor growth of MM tumors. These data imply that PDPN expression in CAFs represents a biomarker for poor prognosis but does not serve as a useful target for stroma‐directed therapy of malignant melanoma.

Unveiling the influence of tumor and immune signatures on immune checkpoint therapy in advanced lung cancer

This study investigates the variability among patients with non-small cell lung cancer (NSCLC) in their responses to immune checkpoint inhibitors (ICIs). Recognizing that patients with advanced-stage NSCLC rarely qualify for surgical interventions, it becomes crucial to identify biomarkers that influence responses to ICI therapy. We conducted an analysis of single-cell transcriptomes from 33 lung cancer biopsy samples, with a particular focus on 14 core samples taken before the initiation of palliative ICI treatment. Our objective was to link tumor and immune cell profiles with patient responses to ICI. We discovered that ICI non-responders exhibited a higher presence of CD4+ regulatory T cells, resident memory T cells, and TH17 cells. This contrasts with the diverse activated CD8+ T cells found in responders. Furthermore, tumor cells in non-responders frequently showed heightened transcriptional activity in the NF-kB and STAT3 pathways, suggesting a potential inherent resistance to ICI therapy. Through the integration of immune cell profiles and tumor molecular signatures, we achieved an discriminative power (area under the curve [AUC]) exceeding 95% in identifying patient responses to ICI treatment. These results underscore the crucial importance of the interplay between tumor and immune microenvironment, including within metastatic sites, in affecting the effectiveness of ICIs in NSCLC.

GPER1 signaling restricts macrophage proliferation and accumulation in human hepatocellular carcinoma

BackgroundSex hormones and their related receptors have been reported to impact the development and progression of tumors. However, their influence on the composition and function of the tumor microenvironment is not well understood. We aimed to investigate the influence of sex disparities on the proliferation and accumulation of macrophages, one of the major components of the tumor microenvironment, in hepatocellular carcinoma (HCC).MethodsImmunohistochemistry was applied to assess the density of immune cells in HCC tissues. The role of sex hormone related signaling in macrophage proliferation was determined by immunofluorescence and flow cytometry. The underlying regulatory mechanisms were examined with both in vitro experiments and murine HCC models.ResultsWe found higher levels of macrophage proliferation and density in tumor tissues from male patients compared to females. The expression of G protein–coupled estrogen receptor 1 (GPER1), a non-classical estrogen receptor, was significantly decreased in proliferating macrophages, and was inversely correlated with macrophage proliferation in HCC tumors. Activation of GPER1 signaling with a selective agonist G-1 suppressed macrophage proliferation by downregulating the MEK/ERK pathway. Additionally, G-1 treatment reduced PD-L1 expression on macrophages and delayed tumor growth in mice. Moreover, patients with a higher percentage of GPER1+ macrophages exhibited longer overall survival and recurrence-free survival compared to those with a lower level.ConclusionsThese findings reveal a novel role of GPER1 signaling in regulating macrophage proliferation and function in HCC tumors and may offer a potential strategy for designing therapies based on understanding sex-related disparities of patients.

DeSide: A unified deep learning approach for cellular deconvolution of tumor microenvironment

Cellular deconvolution via bulk RNA sequencing (RNA-seq) presents a cost-effective and efficient alternative to experimental methods such as flow cytometry and single-cell RNA-seq (scRNA-seq) for analyzing the complex cellular composition of tumor microenvironments. Despite challenges due to heterogeneity within and among tumors, our innovative deep learning–based approach, DeSide, shows exceptional accuracy in estimating the proportions of 16 distinct cell types and subtypes within solid tumors. DeSide integrates biological pathways and assesses noncancerous cell types first, effectively sidestepping the issue of highly variable gene expression profiles (GEPs) associated with cancer cells. By leveraging scRNA-seq data from six cancer types and 185 cancer cell lines across 22 cancer types as references, our method introduces distinctive sampling and filtering techniques to generate a high-quality training set that closely replicates real tumor GEPs, based on The Cancer Genome Atlas (TCGA) bulk RNA-seq data. With this model and high-quality training set, DeSide outperforms existing methods in estimating tumor purity and the proportions of noncancerous cells within solid tumors. Our model precisely predicts cellular compositions across 19 cancer types from TCGA and proves its effectiveness with multiple additional external datasets. Crucially, DeSide enables the identification and analysis of combinatorial cell type pairs, facilitating the stratification of cancer patients into prognostically significant groups. This approach not only provides deeper insights into the dynamics of tumor biology but also highlights potential therapeutic targets by underscoring the importance of specific cell type or subtype interactions.

RIPK2 and lysosomal pathway: Unveiling a new mechanism for lung cancer metastasis

BackgroundThis study aims to explore the role of RIPK2 in lung cancer metastasis and its potential mechanisms. MethodsThe expression levels of RIPK2 in lung cancer patients and cell lines were detected by immunohistochemistry, qRT-PCR, and Western blot. RIPK2 expression was knocked down using siRNA technology, and its effects on the proliferation, migration, and invasion capabilities of lung cancer cells were assessed through CCK-8, EdU, colony formation, and Transwell assays. Furthermore, by overexpressing RIPK2 and LAMP2, the regulatory effect of RIPK2 on the lysosomal pathway and its mechanism of action in lung cancer metastasis were investigated. ResultsThe results showed that the expression of RIPK2 was significantly increased in lung cancer patients and cell lines. Knockdown of RIPK2 significantly inhibited the migration, invasion, and proliferation capabilities of lung cancer cells, while overexpression of RIPK2 promoted these malignant behaviors. Further studies found that RIPK2 promoted lung cancer metastasis by inhibiting LAMP2 expression, thereby suppressing the lysosomal pathway and altering the tumor microenvironment. Additionally, overexpression of LAMP2 could reverse the promotive effects of RIPK2 overexpression on the malignant behaviors of lung cancer cells. ConclusionThis study reveals for the first time that RIPK2 promotes lung cancer metastasis by inhibiting LAMP2 expression, thereby suppressing the lysosomal pathway and altering the tumor microenvironment. In the future, targeted therapy against RIPK2 and LAMP2 may become an effective means to inhibit lung cancer metastasis.

Glioma–Astrocyte connexin43 confers temozolomide resistance through activation of the E2F1/ERCC1 axis

Abstract Background Glioma is the most prevalent and lethal tumor of the central nervous system. Routine treatment with Temozolomide (TMZ) would unfortunately result in inevitable recurrence and therapy resistance, severely limiting therapeutic efficacy. Tumor associated astrocytes (TAAs) are key components of the tumor microenvironment and increasing evidence has demonstrated that aberrant expression of Connexin43 (Cx43) was closely associated with glioma progression and TMZ resistance. However, the specific role of Cx43 in mediating TMZ resistance through glioma and astrocyte interactions has not been fully explored. Methods The expression and prognostic value of Cx43 were evaluated in tumor samples and clinical databases. ShRNA-medicated knockdown and Gfap-Cre Cx43flox/flox gene mouse were used to assessed the role and functional significance of Cx43 in vitro and in vivo. Moreover, we performed mass spectrometry analysis, chromatin immunoprecipitation, and other biochemical assays to define the molecular mechanisms by which Cx43 promotes TMZ resistance. Results We confirmed that upregulation of Cx43 expression between TAAs and glioma cells contributed to TMZ resistance and tumor recurrence. Genetic knockdown or pharmacological inhibition of Cx43 enhanced TMZ-induced cytotoxicity. Mechanistically, elevated Cx43 expression induced β-catenin accumulation at the cell surface of glioma cells, suppressing TCF/LEF transcription, This led to impaired miR-205-5p expression and subsequent activation of E2F1/ERCC1 axis, which eventually led to chemoresistance. Conclusions Our study reveals a novel regulatory mechanism in which the Cx43/miR-205-5p/E2F1/ERCC1 axis contributes to TMZ resistance in glioma. These findings further highlight the potential of targeting Cx43 as a therapeutic strategy in glioma.

MicroRNA-206 as a promising epigenetic approach to modulate tumor-associated macrophages in hepatocellular carcinoma

This letter comments on the recently published manuscript by Huang et al in the World Journal of Gastroenterology , which focused on the immunomodulatory effect of Calculus bovis on hepatocellular carcinoma (HCC) tumor microenvironments (TME) by inhibiting M2-tumor-associated macrophage (M2-TAM) polarization via Wnt/β-catenin pathway modulation. Recent research highlights the crucial role of TAMs and their polarization towards the M2 phenotype in promoting HCC progression. Epigenetic regulation, particularly through microRNAs (miR), has emerged as a key factor in modulating immune responses and TAM polarization in the TME, influencing treatment responses and tumor progression. This editorial focuses on miR-206, which has been found to inhibit HCC cell proliferation and migration and promote apoptosis. Moreover, miR-206 enhances anti-tumor immune responses by promoting M1-polarization of Kupffer cells, facilitating CD8+ T cell recruitment and suppressing liver cancer stem cell expansion. However, challenges remain in understanding the precise mechanisms regulating miR-206 and its potential as a therapeutic agent. Targeting epigenetic mechanisms and improving strategies, whether through pharmacological or genetic approaches, offer promising avenues to sensitize tumor cells to chemotherapy. Understanding the intricate interactions between cancer and non-coding RNA regulation opens new avenues for developing targeted therapies, potentially improving HCC prognosis.

Targeting LLT1 as a potential immunotherapy option for cancer patients non-responsive to existing checkpoint therapies in multiple solid tumors

BackgroundHigh levels of LLT1 expression have been found in several cancers, where it interacts with CD161 on NK cells to facilitate tumor immune escape. Targeting LLT1 could potentially relieve this inhibitory signal and enhance anti-tumor responses mediated through NK cells. Using the ‘The Cancer Genome Atlas’ (TCGA) database, we investigated the role of LLT1 in the tumor microenvironment (TME) across various cancers. Identifying such biomarkers could create new therapeutic options for patients in addition to complementing existing immunotherapies.MethodsLLT1 expression was evaluated in 33 cancers using TCGA transcriptome data. Univariate Cox regression analysis was employed to assess the correlation of LLT1 expression with patient survival. The relationship between LLT1 expression with immune infiltrates, immune gene signatures, and cancer genomic biomarkers (TMB, MSI, and MMR) was also investigated. Immunofluorescence studies were conducted to validate LLT1 expression in tumors. Furthermore, using the CRI iAtlas data, we evaluated LLT1 distribution and its correlation with other immune checkpoint genes in patients non-responsive to existing immune checkpoint therapies across multiple solid cancers.ResultsHigh expression of LLT1 was observed in 12 cancers, including BRCA, CHOL, ESCA, GBM, HNSC, KIRC, KIRP, LIHC, LUAD, STAD, SARC, and PCPG. In certain cancers like COAD, KICH, and KIRC, high LLT1 expression was associated with poor prognosis. Further analysis revealed that upregulated LLT1 was associated with an abundance of NK and T cell infiltrates in the TME, as well as exhaustive immune biomarkers, and inversely associated with pro-inflammatory and tumor suppressor signatures. High LLT1 expression is also positively correlated with genomic biomarkers in certain cancers. Immunofluorescence studies confirmed moderate to high LLT1 expression in immune-resistant prostate cancer, glioma, ovarian cancer, and immune-sensitive liver cancer cell lines. An independent assessment of clinical cohorts from CRI iAtlas showed a correlation of upregulated LLT1 with multiple immunosuppressive genes in patients non-responsive to current ICIs.ConclusionsThe biomarker analysis revealed a clear association between elevated LLT1 expression and an immunosuppressive TME in patient cohorts from TCGA and clinical databases. Therefore, this study provides a foundation for utilizing LLT1 as a potential target to improve clinical responses in ICI non-responsive patients with upregulated LLT1.

Abnormally activated wingless/integrated signaling modulates tumor-associated macrophage polarization and potentially promotes hepatocarcinoma cell growth

In this article, we comment on the article by Huang et al . The urgent development of new therapeutic strategies targeting macrophage polarization is critical in the fight against liver cancer. Tumor-associated macrophages (TAMs), primarily of the M2 subtype, are instrumental in cellular communication within the tumor microenvironment and are influenced by various signaling pathways, including the wingless/integrated (Wnt) pathway. Activation of the Wnt signaling pathway is pivotal in promoting M2 TAMs polarization, which in turn can exacerbate hepatocarcinoma cell proliferation and migration. This manuscript emphasizes the burgeoning significance of the Wnt signaling pathway and M2 TAMs polarization in the pathogenesis and progression of liver cancer, highlighting the potential therapeutic benefits of inhibiting the Wnt pathway. Lastly, we point out areas in Huang et al ’s study that require further research, providing guidance and new directions for similar studies.

Epigenetic Regulation of Immune Cells in Health and Disease: A Comprehensive Review

Epigenetic regulation plays a crucial role in the development, differentiation, and function of immune cells. Mechanisms such as DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA interactions dynamically shape gene expression, enabling immune cells to adapt to environmental stimuli and mediate appropriate immune responses. Aberrant epigenetic regulation is implicated in a range of diseases, including autoimmune disorders, cancer, and chronic inflammatory conditions. In autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis, altered DNA methylation and histone modifications contribute to immune dysregulation and tissue damage. In cancer, immune cells in the tumor microenvironment often exhibit epigenetic changes that facilitate immune evasion. Emerging therapeutic strategies targeting epigenetic pathways, including DNA methyltransferase inhibitors, histone deacetylase inhibitors, and CRISPR-based epigenome editing, offer promising approaches for treating immune-mediated diseases. This review provides a comprehensive overview of the epigenetic mechanisms governing immune cell behavior, their dysregulation in disease, and the potential of epigenetic therapies to restore immune homeostasis and improve patient outcomes. Keywords: Epigenetics, immune cells, DNA methylation, histone modifications, non-coding RNAs, autoimmune diseases, immunotherapy

NEK2 is a potential pan-cancer biomarker and immunotherapy target

BackgroundNEK2 is a member of the NEKs family and plays an important role in cell mitosis. Increasing evidence suggests that NEK2 is associated with the development of multiple tumors, but systematic studies of NEK2 in cancer are still lacking. Therefore, we evaluated the prognostic value of NEK2 in 33 cancers to elucidate the potential function of NEK2 in pan-cancers.MethodsWe investigated the role of NEK2 in pan-cancers utilizing The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) database. Additionally, we analyzed the association between NEK2 gene expression across various cancers, protein expression, the tumor microenvironment (TME), and drug sensitivity using several software and web platforms.The potential oncogenic role of NEK2 was initially explored using bioinformatics methods. Furthermore, we conducted in vitro experiments to preliminarily validate the function of NEK2 in cervical cancer.ResultsNEK2 is overexpressed in almost all tumors, and mutation of NEK2 are associated with a poorer tumor prognosis. In addition, the correlation between NEK2 and immune features such as immune cell infiltration, immune checkpoint genes, tumor mutational burden (TMB), Microsatellite instability(MSI) etc. suggest that NEK2 could potentially be applied in the immunotherapy of tumors.ConclusionNEK2 may be a potential pan-cancer biomarker and immunotherapeutic target for improving the efficacy of tumor therapy.

Differential proteomic profiles of exosomes in pediatric and adult adamantinomatous craniopharyngioma cyst fluid.

Adamantinomatous craniopharyngiomas (ACPs), commonly seen in pediatrics and adults often present with large cystic cavities that can compress surrounding tissues, causing severe visual and endocrine symptoms. Complete resection of cystic ACP is challenging, frequently leading to postoperative recurrence. The composition of the cystic fluid is complex, and to date, there has been limited research focusing on exosomes within ACP cyst fluid. We collected cyst fluid from 12 ACP patients and confirmed the presence of exosomes. Subsequently, we conducted exosomal proteomic analysis using LC-MS/MS. The patients were divided into pediatric and adult groups for the analysis of differential protein enrichment, followed by comprehensive bioinformatics analysis, including GO analysis, KEGG analysis, and PPI network analysis, among other functional pathway and protein interaction analyses. Immunohistochemistry was used to determine the tissue expression distribution of the differential protein APOA1. In our data analysis, 64 significantly differentially expressed proteins were identified, with 37 being overexpressed in the pediatric group and 27 in the adult group. Our results revealed that exosomal proteins in the pediatric group were predominantly enriched in modules and pathways related to high-density lipoprotein particle, apolipoprotein receptor binding, and the PPAR signaling pathway. Additionally, APOA1, as the hub protein with the highest connectivity in the differential protein interaction network, may play a critical role in β-amyloid metabolism pathways in pediatric ACP. This study is the first to construct a proteomic map of ACP cyst fluid exosomes, suggesting significant differences in the tumor microenvironment's lipid metabolism between pediatrics and adults.

The Prognostic Value and Immunotherapeutic Characteristics of GFPT2 in Pan-cancer

Purpose: The purpose of this study is to investigate the underlying relationship of diagnosis and therapy between glutamine-fructose-6-phosphate transaminase 2 (GFPT2) and various cancers. Methods: The Cancer Genome Atlas (TCGA) database was utilized to get gene expression RNAseq and clinical data for 33 tumors. The immunotherapeutic cohorts, including GSE35640, GSE78220, GSE67501, GSE181815, and IMvigor210, were derived from the Gene Expression Omnibus database (GEO) and a previously released article. Differential expression analysis of GFPT2 was performed using several clinical factors, and prognostic analysis was performed using Cox proportional hazard regression. In addition, the Cell type Identification By Estimating Relative Subsets Of RNA transcripts (CIBERSORT) and the Estimation of STromal and Immune cells in MAlignant Tumor tissues utilizing Expression data (ESTIMATE) algorithms were used to investigate the connection between GFPT2 and the tumor microenvironment. This approach additionally incorporated dynamic immunological indicators, such as tumor mutational burden (TMB) and microsatellite instability (MSI). In addition, a correlation between GFPT2 expression and the effectiveness of anticancer drugs was plotted for discussion. Results: GFPT2 expression significantly differed in 11 out of 33 cancers. Although the distinct correlation between GFPT2 expression and clinical parameters had no wide distribution in pan-cancer, it demonstrated the potential prognostic validity of gene expression. GFPT2 demonstrated a strong correlation with immune infiltration, immune modulators, and immunerelated biomarkers. Furthermore, a variance analysis demonstrated a significant relationship between GFPT2 and the efficacy of immunotherapy. In addition, GFPT2 was associated with increased sensitivity of drugs such as Olaparib and Lenvatinib and decreased sensitivity of drugs such as Nilotinib. Conclusion: Collectively, GFPT2 is potentially useful as a biomarker for prognostic prediction and immune infiltration in a variety of malignancies ,and could lead to exciting new approaches to personalized oncotherapy.

Distinctive grade based on Ki67 index and immune microenvironment of metastatic pancreatic neuroendocrine tumors responding to capecitabine plus temozolomide

BackgroundKi67 index changes during the treatment of metastatic pancreatic neuroendocrine tumor (PanNET) treatment. The study aimed to detect alterations of grade based on Ki67 index and immune microenvironment in PanNET responding to capecitabine/temozolomide (CapTem).MethodRetrospective data of patients with PanNET were collected. In control group, 35 patients underwent surgery immediately after biopsy. In CapTem group, 38 patients received CapTem after biopsy and responded well to treatment (defined as either stable disease or partial response), and subsequently underwent surgery. All patients have pathological Ki67 index at biopsy and after surgery. CD163 + CD68 + CD206 + M2 macrophages, CD68 + CD86 + CD80 + M1 macrophages, CD11b + CD33 + myeloid-derived suppressor cells, and CD4 + CD25 + regulatory T cells were stained using multiplex immunofluorescence.ResultsIn control group, the paired grade based on Ki67 index directly after surgery showed no upgrade or downgrade compared to biopsy. In patients who responded well to CapTem, the grade based on Ki67 index before and after CapTem was altered. Thirteen patients had upgraded Ki67 index and 11 patients had downgraded. The proportion of stable disease was higher in the upgraded group compared to downgraded group (p = 0.0155). And upgraded group had a significantly shorter mPFS than patients in the downgrade group (8.5 months vs. 20 months, HR 4.834, 95% CI 1.414 to 16.53, p = 0.012). M1 macrophages was significantly lower in the downgraded group than in the Ki67 upgraded group (p < 0.001).ConclusionGrade based on Ki67 index and immune environment change in PanNET patients responding well to CapTem. Patients with downgraded had longer mPFS compared to those with upgraded. It is necessary to reassess the Ki67 index after CapTem treatment, even in patients responding well to CapTem.

Exploring Tumor Microenvironment in Breast Cancer: Parameters that can be Assessed with Light Microscopy.

Exploring Tumor Microenvironment in Breast Cancer: Parameters that can be Assessed with Light Microscopy.

Elevated ITGA3 expression serves as a novel prognostic biomarker and regulates tumor progression in cervical cancer

Patients with advanced and recurrent cervical cancer often lack satisfactory treatment outcomes. Thus, it is necessary to seek reliable biomarkers that provide the ability to identify the disease at an early stage and predict the patient prognosis, providing new strategies for the treatment of cervical cancer. The sequencing data of ITGA3 were retrieved from public datasets. Immune infiltration and sensitivity of potential immunotherapy and chemotherapy have been analyzed between two subgroups. Functional analysis was applied to excavate the related pathways of ITGA3 in cervical cancer. Furthermore, the impact of ITGA3 in tumor progression has been verified in vitro. The results revealed that the level of ITGA3 was upregulated in cervical cancer, and was positively correlated with worse prognosis. The tumor microenvironment of patients in the high-risk group was immunosuppressed. Patients in high-risk group may not benefit from immunotherapy, but be may be sensitive to several chemotherapy drugs. Notably, the angiogenesis, epithelial mesenchymal transition, and PI3K pathway were increased in high-risk group. Collectively, ITGA3 is a marker of poor prognosis and promotes tumor progression by regulating PI3K/AKT pathway in cervical cancer. Our results provide new insights for potential molecular targeted therapy and prognostic prediction of cervical cancer.

Adipocytes reprogram the proteome of breast cancer cells in organotypic three-dimensional cell cultures.

While epidemiological evidence has long linked obesity with an increased risk of breast cancer, the intricate interactions between adipocytes and cancer cells within the tumor microenvironment remain largely uncharted territory. The use of organotypic three-dimensional (3D) cell cultures that more accurately mimic the spatial architecture of tumors represents an innovative approach to this complex issue. In the present study, we investigated the effects of adipocytes on the proteome of Hs578t breast cancer cells cultured in a 3D microenvironment. Using different treatments, we rigorously optimized the experimental conditions to induce the optimal differentiation of 3T3-L1 fibroblasts into mature adipocytes. Then, we grow the Hs578t cells in a simulated microenvironment using an on-top model for organotypic 3D cultures. Our data showed that cancer cells formed 3D stellate-like architectures when grown over an extracellular matrix proteins-enriched scaffold for 48h. Proteomic profiling using LC-MS/MS mass spectrometry of Hs578t cells grown in 3D conditions with or without the adipocyte-enriched culture discovered 916 unique proteins. Of these, 605 showed no significant changes in abundance, whereas 87 proteins were significantly upregulated and 224 downregulated after interaction with fat cells (p < 0.05, FC > 2.0). Bioinformatic analysis of upregulated proteins indicated that the most enriched GO terms and molecular functions were related to lipids transport, cell differentiation, hypoxia response, and cell junctions. In addition, several modulated proteins have been previously associated with breast cancer progression. Interestingly, lipid transport proteins, including PITPNM2, ATP2C1, ABCA12, HDLBP, and APOB, showed perturbations in their expression, which were also associated with low overall survival in breast cancer patients. Functional studies showed that the knockdown of apolipoprotein B (APOB) expression in Hs578t cells reduced the size of 3D cellular structures. Moreover, APOB-knocked cells cocultured with adipocytes for 48h exhibited a significant decrease of intracellular lipids, whereas an increase in the adipocytes was found. Our results indicate that the 3D microenvironment and the adipocytes crosstalk reprogram the proteome of breast cancer cells. These data help us understand the environmental effects in gene expression and contribute to discovering novel tumor proteins with potential intervention in breast cancer therapy.

Histone Lysine Lactylation (Kla)-induced BCAM Promotes OSCC Progression and Cis-Platinum Resistance.

Histone lysine lactylation (Kla) plays a vital role in cancer progression. However, the prognostic value of histone Kla in oral squamous cell carcinoma (OSCC) remains unclear. OSCC RNA expression data were obtained from the TCGA and GEO databases. We explored the prognostic value of histone Kla in OSCC via constructing a Cox model and determined the role of Kla in OSCC drug susceptibility and tumor microenvironment (TME). In addition, the biological roles of candidate biomarkers were identified. A total of 1223 Kla-specific genes were obtained, with 228 DEKlaGs in OSCC. GO and KEGG enrichment analyses suggested that DEKlaGs contributed to inflammatory and cancer progression. A Cox model in accordance with BCAM, CGNL1, DGKG, and OLR1 could predict OSCC patient prognosis accurately. Subsequently, Kla-induced prognostic genes were identified to play a crucial role in OSCC drug therapy and TME. Moreover, BCAM was identified as a biomarker that promoted OSCC invasion, angiogenesis, and chemotherapy resistance. Kla was identified to be associated with OSCC prognosis, drug therapy, and TME. Histone Kla-induced BCAM was identified to play a crucial role during OSCC progression, suggesting that Kla is promising to be a novel therapeutic target for OSCC.

FGL2172-220 peptides improve the antitumor effect of HCMV-IE1mut vaccine against glioblastoma by modulating immunosuppressive cells in the tumor microenvironment

ABSTRACT Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor characterized by poor prognosis and lack of effective treatments. In recent years, peptide vaccines that use sequences based on tumor-specific or tumor-associated antigens to activate immune responses against tumor cells have emerged as a new therapeutic strategy. In this study, we developed a novel therapeutic polypeptide vaccine targeting the tumor-associated antigen Fibrinogen-Like Protein 2 (FGL2), whose dominant epitope peptide was tandemly linked to the C-terminus of HCMV-IE1mut via a linker. We used this vaccine to compare the therapeutic efficacy of HCMV-IE1mut alone versus HCMV-IE1mut-FGL2172-220 and investigate the potential mechanism of action of HCMV-IE1mut-FGL2172-220 in glioma treatment. An in situ GBM model (GL261-IE1-luc cells) was used to determine the efficacy of the vaccine. Treatment with HCMV-IE1mut-FGL2172-220 exerted antitumor effects and extended the survival of the GL261 animal model. We observed reduced proportions of microglia, regulatory T cells (Treg), and myeloid-derived suppressor cells (MDSC) in the tumor microenvironment (TME) by immunofluorescence. Flow cytometry showed that compared to HCMV-IE1mut alone, treatment with HCMV-IE1mut-FGL2172-220 increased the proportion of CD8+ T cells and tissue-resident memory T cells (TRM). ELISA analysis showed that it improved the secretion of tumor-specific IFN-γ and TNF-α by these cells and downregulated the expression of IL-6 and IL-10. Our study demonstrates that the long-peptide FGL2172-220 improves the antitumor efficacy of HCMV-IE1mut, possibly by reshaping immune cells in the glioma microenvironment. These findings lay the groundwork for the development of therapeutic antigenic peptide vaccines to improve antitumor effects for cancer.