Stromal Cells In Tumor Microenvironment Research Articles

LncRNAs in Immune and Stromal Cells Remodel Phenotype of Cancer Cell and Tumor Microenvironment.

Emerging studies suggest that long non-coding RNAs (lncRNAs) participate in the mutual regulation of cells in tumor microenvironment, thereby affecting the anti-tumor immune activity of immune cells. Additionally, the intracellular pathways mediated by lncRNAs can affect the expression of immune checkpoints or change the cell functions, including cytokines secretion, of immune and stromal cells in tumor microenvironment, which further influences cancer patients' prognosis and treatment response. With the in-depth research, lncRNAs have shown great potency as a new immunotherapy target and predict immunotherapy response. The research on lncRNAs provides us with a new insight into developing new immunotherapy drugs and predicting the outcome of immunotherapy. With development of RNA sequencing technology, amounts of lncRNAs were found to be dysregulated in immune and stromal cells rather than tumor cells. These lncRNAs function through ceRNA network or regulating transcript factor activity, thus leading abnormal differentiation and activation of immune and stromal cells. Here, we review the function of lncRNAs in the immune microenvironment and focus on the alteration of lncRNAs in immune and stromal cells, and discuss how these alterations affect tumor growth, metastasis and treatment response.

Abstract A034: 3D in-vitro model picturing cancer-stromal cell crosstalk & bone metastasis

Abstract Breast cancer is presently the most prevalent malignancy and the second leading cause of tumor-related deaths among women. Approximately 75% of patients with advanced breast cancer will develop bone metastasis. Despite the significant improvement in treating primary breast cancer, the 5-year survival rate for metastatic breast cancer remains at 25%. While we recognize the critical importance of cancer cells and Tumor Microenvironment (TME) communication, the field still suffers from a lack of a proper model system to reconstitute 3D multi-cellular TME in-vitro, especially for bone metastasis. Most of the current 3D in-vitro breast cancer models are composed of cancer cells only and are unable to mimic the complex cellular homeostasis within the TME. To address this deficiency along with the tumor heterogeneity, we aimed to develop a unique 3D multi-cellular culture system using patient-derived (PD) cancer cells. In this study, we implemented the “hanging drop” method to create 3D Tumor Spheroids (TSs). This method was not only sufficient to build the 3D structure, but also significantly enhanced patient-derived cancer cell line establishment rate up to 75%. 3D TSs maintained their histopathological characteristics and original hormone receptor status. Over time, TSs exhibited intratumoral hypoxia leading to significant induction of VEGF expression and EMT showcasing the quality of the system. To investigate the complex interrelation between the tumor and TME, we cultured TSs with Endothelial Cells (ECs) and pericytes to introduce the vascular component. To probe these tumor-stromal interactions, we incorporated Cancer-Associated Fibroblasts (CAFs) into TSs and observed the successful growth of Multi-Cellular Tumor Spheroids (MCTSs) alongside the tubular structure. Analysis of our data revealed that the presence of stromal cells in TME enhanced tumor survival. In this study, we define how CAFs aid in the formation of vascular structures of ECs. Recent studies also have found that the effects of CAFs are significantly high in aggressive TNBC and HER2+ cell lines compared to HR+. The long-term goal of this current study is to explore bone-mimicking nano-clay-based 3D scaffold culture systems to investigate the development of metastatic tumors and to understand the influence of bone TME on cellular responses in-vitro. Citation Format: Shrinwanti Ghosh. 3D in-vitro model picturing cancer-stromal cell crosstalk & bone metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A034.

Cancer-associated fibroblasts-induced remodeling of tumor immune microenvironment via Jagged1 in glioma

Tumor immunosuppression are prominent characteristics of brain glioma. Current standard modality including surgical resection and chemoradiotherapy do not significantly improve clinical outcomes. Cancer-associated fibroblasts (CAFs) that regard as important stromal cells in tumor microenvironment have been confirmed to play crucial roles in tumor development. However, the effects of CAFs on tumor immunosuppression in glioma are not well expounded. In this study, we report that CAFs contributes to the formation of glioma immunosuppressive microenvironment. Specifically, we found that glioma-derived Jagged1 enhanced the proliferation and PD-L1 expression of CAFs in vitro. Importantly, we discovered that Notch1, c-Myc and PD-L1 expression were significantly increased in high Jagged1-expressing gliomas, moreover, we further confirmed that Notch1 and PD-L1 expression located on the CAFs in glioma tissues. We also found that glioma-derived Jagged1 promotes the increase of tumor-infiltrating macrophages, M2 macrophages and Foxp3 Treg cells, as well as no significance of M1 macrophages and CD8+ T cells, indicating potential immunosuppression. This study opens up novel therapeutic strategies reversing CAF immunosuppression for gliomas.

Identification of stromal cell proportion-related genes in the breast cancer tumor microenvironment using CorDelSFS feature selection: implications for tumor progression and prognosis.

Background: The tumor microenvironment (TME) of breast cancer (BRCA) is a complex and dynamic micro-ecosystem that influences BRCA occurrence, progression, and prognosis through its cellular and molecular components. However, as the tumor progresses, the dynamic changes of stromal and immune cells in TME become unclear. Objective: The aim of this study was to identify differentially co-expressed genes (DCGs) associated with the proportion of stromal cells in TME of BRCA, to explore the patterns of cell proportion changes, and ultimately, their impact on prognosis. Methods: A new heuristic feature selection strategy (CorDelSFS) was combined with differential co-expression analysis to identify TME-key DCGs. The expression pattern and co-expression network of TME-key DCGs were analyzed across different TMEs. A prognostic model was constructed using six TME-key DCGs, and the correlation between the risk score and the proportion of stromal cells and immune cells in TME was evaluated. Results: TME-key DCGs mimicked the dynamic trend of BRCA TME and formed cell type-specific subnetworks. The IG gene-related subnetwork, plasmablast-specific expression, played a vital role in the BRCA TME through its adaptive immune function and tumor progression inhibition. The prognostic model showed that the risk score was significantly correlated with the proportion of stromal cells and immune cells in TME, and low-risk patients had stronger adaptive immune function. IGKV1D-39 was identified as a novel BRCA prognostic marker specifically expressed in plasmablasts and involved in adaptive immune responses. Conclusions: This study explores the role of proportionate-related genes in the tumor microenvironment using a machine learning approach and provides new insights for discovering the key biological processes in tumor progression and clinical prognosis.

Abstract 2502: The role of high mobility group box-1 protein (HMGB1) in the microenvironment of non-small cell lung cancer

Abstract Introduction: The tumor microenvironment (TME) is critical in determining tumor development and progression. Among stromal cells in TME, cancer associated fibroblasts (CAFs) play a central role and are involved in various signals through their interaction with cancer cells in most solid tumors, leading to cancer progression and acquisition of drug resistance. Under these TME conditions, tumor cell death such as necrosis occurs, which in turn, results in the ectopic release of bioactive molecules collectively termed as damage-associated molecular patterns (DAMPs), which has been reported to play an important role in cancer progression. The purpose of this study is to clarify the effects of cancer cell-derived HMGB1, a representative DAMPs, on CAFs and to investigate whether it could be a potential therapeutic target. Methods: We established CAFs from resected non-small cell lung cancer (NSCLC) specimens and investigated the biological activity of HMGB1 on CAFs using in vitro co-culture models with NSCLC cell lines. Furthermore, we assessed the therapeutic efficacy of targeting cancer cell-derived HMGB1 using anti-HMGB1 neutralizing antibody. Results: Intracellular HMGB1 was expressed more in NSCLC cells than in normal bronchial epithelial cells and CAFs, and released from cancer cells extracellularly upon treatment with anticancer drugs. The stimulation with recombinant HMGB1 promoted the proliferation of CAFs in a dose-dependent manner, but not lung cancer cells. Co-culture with CAFs promoted cancer cells’ migratory ability and drug resistance, and stimulation with recombinant HMGB1 further enhanced these promoting effects, while administration of anti-HMGB1 neutralizing antibody suppressed these effects. On the other hand, these inhibitory effects were not observed in the absence of CAFs, suggestingHMGB1 has effect on CAFs, but not direct on cancer cells. Conclusion: HMGB1 plays an important role in cancer progression and acquisition of therapeutic resistance by upregulating the CAFs’ proliferation and activity and could be a therapeutic target in NSCLC. Citation Format: Tomohiro Habu, Keiichi Date, Ken Suzawa, Mao Yoshikawa, Masayoshi Ohki, Kazuma Iwata, Naoki Matsuda, Yin Min Thu, Kazuhiko Shien, Hiromasa Yamamoto, Shinichi Toyooka. The role of high mobility group box-1 protein (HMGB1) in the microenvironment of non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2502.

The adenosinergic machinery in cancer: In-tandem insights from basic mechanisms to therapy.

Extracellular adenosine (eADO) signaling has emerged as an increasingly important regulator of immune responses, including tumor immunity. eADO is mainly produced from extracellular ATP (eATP) hydrolysis. eATP is rapidly accumulated in the extracellular space following cell death or cellular stress triggered by hypoxia, nutrient starvation, or inflammation. eATP plays a pro-inflammatory role by binding and activating the P2 purinergic receptors (P2X and P2Y), while eADO has been reported in many studies to mediate immunosuppression by activating the P1 purinergic receptors (A1, A2A, A2B, and A3) in diverse immune cells. Consequently, the hydrolysis of eATP to eADO alters the immunosurveillance in the tumor microenvironment (TME) not only by reducing eATP levels but also by enhancing adenosine receptor signaling. The effects of both P1 and P2 purinergic receptors are not restricted to immune cells. Here we review the most up-to-date understanding of the tumor adenosinergic system in all cell types, including immune cells, tumor cells, and stromal cells in TME. The potential novel directions of future adenosinergic therapies in immuno-oncology will be discussed.

Cancer-associated fibroblasts contribute to cancer metastasis and apoptosis resistance in human ovarian cancer via paracrine SDF-1α.

Cancer-associated fibroblasts (CAFs), one of the main members of stromal cells in tumor microenvironment are proposed to play a central role in promoting tumor metastasis. It is unclear whether and how CAFs mediates tumor metastasis or chemoresistance in human ovarian cancer. CAFs were extracted from human ovarian cancer tissues (OCs) of patients with different kinds of histological types. We found that CAFs showed more aggressive potency than those tumor cells, both of which were isolated from the same ovarian cancer specimen. Moreover, when co-cultured with CAFs, cell migration abilities of ovarian cancer cells (SKOV3, OVCAR3 and HEY) were significantly increased. Next, we preliminarily detected a higher CAFs density in sections of metastatic lesions than those in primary tumor site of primary OCs clinically. However, no significant difference of stromal derived factors-1α (SDF-1α) production from CAFs was found between primary and metastatic lesions. Additionally, in contrast with tumor cells, CAFs exhibited obvious apoptosis resistance when treated with cisplatin. Furthermore, we found that cisplatin-induced cytotoxicity and apoptosis were significantly inhibited by co-cultured with recombinant human SDF-1α in SKOV3 in a time and dose-dependent manner, and this effect was suppressed by the CXCR4 antagonist AMD3100. CAFs might be involved in the malignant metastasis in human ovarian cancer through promoting cell migration in tumor cells. And their resistance to cytotoxic agents might be mediated by paracrine SDF-1α/CXCR4 signaling in ovarian cancer.

The Cancer-Associated Fibroblasts-Related Gene COMP Is a Novel Predictor for Prognosis and Immunotherapy Efficacy and Is Correlated with M2 Macrophage Infiltration in Colon Cancer.

Colon cancer is characterized by a sophisticated tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), which make up the majority of the stromal cells in TME, participate in tumor development and immune regulation. Further investigations of CAFs would facilitate an in-depth understanding of its role in colon cancer TME. In this study, we estimated CAF abundance based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases using the Microenvironment Cell Populations-counter (MCP-counter) algorithm. CAF-related genes were identified by differential gene expression analysis combined with weighted gene coexpression network analysis. For further selection, the least absolute shrinkage and selection operator (LASSO)-Cox regression was used, and the prognostic value of the selected gene was confirmed in numerous external cohorts. The function enrichment, immunological characteristics, tumor mutation signature, immunotherapy response, and drug sensitivity of the selected gene were subsequently explored. The bioinformatics analysis results were validated using immunohistochemistry on clinical samples from our institution. According to our findings, cartilage oligomeric matrix protein (COMP) was uncovered as a candidate CAFs-driven biomarker in colon cancer and plays an important role in predicting prognosis in colon cancer. COMP upregulation was associated with enhanced stromal and immune activation, and immune cell infiltration, especially M2 macrophages. Genes that mutated differently between the high- and low-COMP expression subgroups may be correlated with TME change. Following verification, COMP reliably predicted the immunotherapy response and drug response. In addition, our experimental validation demonstrated that COMP overexpression is associated with colon cancer carcinogenesis and is strongly associated with CAFs and M2 macrophage infiltration. Our study uncovered that COMP was a key CAFs-driven gene associated with M2 macrophage infiltration and acted as a convincing predictor for prognosis and immunotherapy response in colon cancer patients.

Tumor cell-derived conditioned medium induced pro-tumoral phenotypes in macrophages through calcium-nuclear factor κB interaction

BackgroundThe malignant behaviors of lung cancers are affected by not only cancer cells but also many kinds of stromal cells in tumor microenvironment (TME), including macrophages. Macrophages have been proven to extensively influence tumor progression through several mechanisms, among which switching of macrophages from pro-inflammatory phenotypes (M1-like) to anti-inflammatory phenotypes (M2-like) mediated by transcription factors such as nuclear factor κB (NF-κB) is the most crucial event. The regulation of NF-κB has been well studied, however some details remain fuzzy.MethodsMouse primary bone marrow-derived macrophages (BMDMs) were cultured in Lewis lung carcinoma cell line LL-2-derived conditioned medium (LL-2-CM). Proliferation, migration, and polarization of BMDMs were tested by CCK8, scratch test, transwell, and flow cytometry. Secretion of several cytokines were detected by ELISA or cytometric bead array. To further explore the underlying mechanisms, BMDMs cultured in LL-2-CM were harvested for RNA-seq. Cytosolic calcium was detected by calcium probe Fluo-4-AM. Western blot was applied to exam the activation of NF-κB signal. BAPTA-AM was applied to sequestrate cytosolic calcium to further investigate the relationship between calcium and NF-κB signal. The polarization, calcium alteration, and NF-κB signal activation were further validated in BMDMs treated by CMT-64-derived conditioned medium (CMT-64-CM).ResultsLL-2-CM promoted proliferation, migration, and M2-like polarization of BMDMs and inhibited M1-like polarization of BMDMs. However two pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-mathrm{alpha } (TNF-mathrm{alpha }) were secreted. RNA-seq indicated that LL-2-CM activated both canonical and non-canonical NF-κB signal in BMDMs. Western blot showed that canonical NF-κB was temporarily elicited and attenuated at 24 h, while non-canonical NF-κB was consistently activated. At the same time, expression of genes that regulate cytosolic calcium ion concentration were down regulated, which caused diminution of cytosolic calcium in BMDMs treated with LL-2-CM. The decreased cytosolic calcium, M2-like polarization, and NF-κB activation was also observed in CMT-64-CM treated BMDMs. On the contrary, elevated cytosolic calcium was observed during M1-like polarization of BMDMs elicited by lipopolysaccharide (LPS). Interestingly, administration of calcium chelator, BAPTA-AM, impeded activation of canonical NF-κB and expression of M1-like marker induced by LPS, which further confirmed the relationship between cytosolic calcium and canonical NF-κB signal.ConclusionsIn summary, lung cancer cell-derived conditioned medium promoted migration, proliferation, and M2-like polarization of BMDMs. The suppressed M1-like polarization was achieved through mitigating canonical NF-κB pathway via diminishing cytosolic calcium concentration. As far as we know, our work firstly revealed that cytosolic calcium is the key during inhibition of canonical NF-κB and M1-like polarization in macrophages by tumor cells.

Exosomes Derived from Immune Cells: The New Role of Tumor Immune Microenvironment and Tumor Therapy.

Exosomes are small vesicles secreted by living cells, with a typical lipid bilayer structure. They carry a variety of proteins, lipids, RNA and other important information, play an important role in the transmission of substances and information between cells, and gradually become a marker for early diagnosis of many diseases and an important tool in drug delivery system. Immune cells are an important part of tumor microenvironment, and they can affect tumor progression by secreting a variety of immunoreactive substances. This review focuses on the effects of various immune cell-derived exosomes on tumor cells, different immune cells and other stromal cells in tumor microenvironment. Exosomes derived from different immune cells can not only reshape a pro-inflammatory microenvironment to inhibit tumor progression, but also promote tumor progression by inhibiting the killing effect of NK cells, CD8+T cells and other cells or promoting tumor cells and immunosuppressive immune cells. In addition, we also discussed that some exosomes derived from immune cells (such as DC, M1 macrophages and neutrophils) play a tumor inhibitory role after being engineered.

Reprogramming of Activated Pancreatic Stellate Cells via Mechanical Modulation of Transmembrane Force-sensitive N-cadherin Receptor

Cancer has been the leading cause of death due mainly to tumor metastasis. The tumor microenvironment plays a key role in tumor metastasis. As the main stromal cells in tumor microenvironment originated from activated fibroblast, cancer-associated fibroblasts (CAFs) play a major role in promoting tumor metastasis. A promising therapeutic avenue is reprogramming of CAFs into tumor-restraining quiescence state. In this study, we observed that CAF-like active pancreatic stellate cells (PSCs) interact with each other via N-cadherin, a force-sensitive transmembrane receptor. Since N-cadherin ligation mediated mechanotransduction has been reported to restrict integrin mediated signalling, we thus hypothesized that the reprogramming of activated PSCs by mechanical modulation of N-cadherin ligation might be possible. To test this hypothesis, we grafted N-cadherin ligand (HAVDI peptide) onto soft polyethylene glycol hydrogel substrate prior to cell adhesion to mimic cell–cell interaction via N-cadherin ligation. We found that the activated PSCs could be reprogrammed to their original quiescent state when transferred onto the substrate with immobilized HAVDI peptide. These results reveal a key role of mechanosensing by intercellular transmembrane receptor in reprogramming of activated PSCs, and provide a potential way for designing novel therapeutic strategies for cancer treatment.

Identification and validation for biological characteristics and prognosis of tumor microenvironment subtypes in patients with lung adenocarcinoma.

e21006 Background: Immunotherapy has brought a great revolution to treatment of patients with lung adenocarcinoma (LUAD). However, the infiltrating cells in the tumor microenvironment (TME) could influence immunotherapy outcomes. This study aimed to investigate the TME subtypes based on 50 immune, stromal, and stem cell types in TME. Methods: The xCell algorithm was used to infer the enrichment scores in TME. We performed the k-mean consensus clustering to identify TME subtypes for LUAD patients. The ESTIMATE, ABSOLUTE, LUMP, and CPE algorithms were used to compare tumor purity and immune infiltration of TME subtypes. The genomic mutations and copy number variants were also calculated by “maftools” R package and GISTIC 2.0. We established a neural network model, based on the TCGA dataset and verified it in GEO datasets by the Kaplan-Meier curve and Cox regression analyses, to prove the stability of TME subtypes. Using prophetic algorithm, ridge regression model was established to predict the sensitivity of drugs in all datasets. In addition, TIDE score and submap analyses were used to speculate the potential response of patients in immunotherapy. Results: In our study, 50 types of cells, including immune (including lymphocyte and myeloid cells), stem, and stromal cells in TME, were included for analysis. Based on cell scores, 504 LUAD patients were divided into four different subtypes (C1, C2, C3 and C4). In univariable Cox regression, the hazard ratio (HR) value of C2 vs. C1 was 2.066 (95%CI: 1.313 - 3.250), the HR value of C3 vs. C1 was 1.821 (95%CI: 1.067- 3.108), and that of C4 vs. C1 was 2.313 (95%CI: 1.461 - 3.662). Then, a neural network model was established (the area under the curves in the testing cohort: 0.911) to validate our conclusions in external sets and similar results were observed. Through pseudotime trajectory, we discovered there were potential connections among clusters from C1 to C4. The C2 and C3 were the intermediate forms of C1 and C4, and thus, the survival, immunological, and metabolic status of C2 and C3 may be intermediate between C1 and C4. By comparing the cell infiltration and immune gene expression of the four clusters, we found that C1 and C3 may have a similar immune phenotype which was opposed to that of C2 and C4. Meanwhile, the enrichment scores of cell proliferation-related pathways were progressively increased in the four clusters, which may be related to survival outcomes of them. We noticed that C1 harbored a unique EGFR mutation compared to other clusters, which may be sensitive to erlotinib. Patients of C4 had lower TIDE scores, which indicated that these patients may get higher benefits from immunotherapy. Conclusions: In conclusion, we identified four TME subtypes with distinct clinical outcomes and biological features, including tumor immunity, TME status, tumor mutations, and responses to chemotherapy and immunotherapy.

Construction of an algorithm based on oncosis-related LncRNAs comprising the molecular subtypes and a risk assessment model in lung adenocarcinoma.

BackgroundAs an important non‐apoptotic cell death method, oncosis has been reported to be closely associated with tumors in recent years. However, few research reported the relationship between oncosis and lung cancer.MethodsIn this study, we established an oncosis‐based algorithm comprised of cluster grouping and a risk assessment model to predict the survival outcomes and related tumor immunity of patients with lung adenocarcinomas (LUAD). We selected 11 oncosis‐related lncRNAs associated with the prognosis (CARD8‐AS1, LINC00941, LINC01137, LINC01116, AC010980.2, LINC00324, AL365203.2, AL606489.1, AC004687.1, HLA‐DQB1‐AS1, and AL590226.1) to divide the LUAD patients into different clusters and different risk groups. Compared with patients in clsuter1, patients in cluster2 had a survival advantage and had a relatively more active tumor immunity. Subsequently, we constructed a risk assessment model to distinguish between patients into different risk groups, in which low‐risk patients tend to have a better prognosis. GO enrichment analysis revealed that the risk assessment model was closely related to immune activities. In addition, low‐risk patients tended to have a higher content of immune cells and stromal cells in tumor microenvironment, higher expression of PD‐1, CTLA‐4, HAVCR2, and were more sensitive to immune checkpoint inhibitors (ICIs), including PD‐1/CTLA‐4 inhibitors. The risk score had a significantly positive correlation with tumor mutation burden (TMB). The survival curve of the novel oncosis‐based algorithm suggested that low‐risk patients in cluster2 have the most obvious survival advantage.ConclusionThe novel oncosis‐based algorithm investigated the prognosis and the related tumor immunity of patients with LUAD, which could provide theoretical support for customized individual treatment for LUAD patients.

Reduced CCR2 Can Improve the Prognosis of Sarcoma by Remodeling the Tumor Microenvironment.

BackgroundThe tumor microenvironment (TME) plays a very important role in the development of sarcoma (SARC), but it is still unknown how to effectively regulate the TME.AimOur study aims to identify core molecules that can concurrently regulate immune and stromal cells in TME as potential therapeutic targets.Methods and ResultsWe used the ESTIMATE algorithm to score the immune and stromal components of 265 SARC samples and determined that increased immune and stromal components in TME were both associated with poor prognosis in SARC. Next, we identified differential genes that regulate both immune and stromal cells, and identified the core prognostic gene CCR2 through the protein–protein interaction (PPI) network, COX analysis, survival analysis, and GSEA enrichment analysis. Next, we calculated the content of infiltrating immune cells and stromal cells in tumors using the CIBERSORT and xcell algorithms, respectively. Using differential analysis and Spearman correlation analysis, we identified 12 immune cells and 7 stromal cells, including CD4+T cells, CD8+T cells, monocytes, macrophages, dendritic cells, NK cells, mesenchymal stem cells (MSC), Fibroblasts and Endothelial cells, all of which were regulated by CCR2.ConclusionIncreased immune and stromal cell components were associated with poor prognosis in SARC, and CCR2 had a prognostic role in TME, regulating multiple immune and stromal cells, and was an important target for TME remodeling as well as immunotherapy in SARC.

The mechanism of LncRNA01977 in lung adenocarcinoma through the SDF-1/CXCR4 pathway.

BackgroundA significant correlation has been identified between lncRNA and tumor cell resistance, diagnosis, and prognosis. Although mRNA studies have dominated the field of non-coding RNA biology in tumorigenesis in recent years, long-chain non-coding RNA (the biological function) has also attracted increasing attention. However, the lncRNA associated with lung adenocarcinoma (LUAD) remains unexplored. This study used bioinformatics analysis to screen and identify LncRNA01977 as a key oncogenic driver of LUAD.MethodsThe experiment was divided into blank serum group (normal serum medium) and lung compound low, medium and high dose groups (5%, 10%, 15% and 15% lung compound drug serum medium, respectively). Transwell invasion ability of A549 cells was detected, and Western blot tested A549 cells SDF-1 specific receptor CXCR4, and CXCR4 gene expression in A549 cells were determined by reverse transcription–polymerase chain reaction (RT-PCR). In addition, western blotting, MTT proliferation test, colony formation test and apoptosis detection techniques were used to explore the mechanism of LncRNA01977's effects on LUAD.ResultsIn vitro assays demonstrated that LncRNA01977 can significantly promote the progression of LUAD and that stromal cells in tumor microenvironment secrete chemokine CXCL12, also known as stromal derived factor-1 (SDF-1), and its receptor CXCR4 is low expressed in normal tissues and high expressed in LUAD tissues. Lung cancer patients with high expression of CXCR4 are more prone to metastasis.ConclusionsLncRNA01977 can be used as a new prognostic indicator of LUAD, and can help patients to find more effective target treatment options for LUAD.

Tumor Microenvironment and its Implications for Antitumor Immunity in Cholangiocarcinoma: Future Perspectives for Novel Therapies.

The incidence of cholangiocarcinoma (CCA) has been increasing over the past few years. Although there are surgery, chemotherapy and other conventional treatment methods, the effect is not as expected. At present, immunotherapy has become the research frontier of cancer treatment, and CCA tumor microenvironment (TME) is becoming a hot exploration direction of immunobiology. TME can affect tumor progression through changes in metabolism, secretion and immunity. Accordingly, understanding the role played by immune cells and stromal cells in TME is important for the study of CCA immunotherapy. This review will discuss the interactions between immune cells (including CD8+ T cells, CD4+ T cells, macrophages, natural killer cells, dendritic cells, myeloid suppressor cells, mast cells, and neutrophils) and stromal cells (including cancer-associated fibroblasts, endothelial cells) in the TME of CCA. In addition, we will also discuss current research results on TME of CCA and recent advances in immunotherapy.

Identification of Key Genes Driving Tumor Associated Macrophage Migration and Polarization Based on Immune Fingerprints of Lung Adenocarcinoma.

The identification of reliable indicators in the tumor microenvironment (TME) is critical for tumor prognosis. Tumor associated macrophages (TAMs) are the major component of non-tumor stromal cells in TME and have increasingly been recognized as a predictive biomarker for lung adenocarcinoma (LUAD) prognosis. Here, we report the development of a prognosis model for LUAD using three immune-related genes (IRGs) detected in The Cancer Genome Atlas (TCGA) which potentially regulate TAMs in TME. In 497 LUAD patients, higher immune scores conferred better overall survival (OS). We identified 93 hub IRGs out of 234 for further prognostic significance. Among them, three IRGs (BTK, Cd1c, and S100P) were proved to be closely correlated to the prognosis of patients with LUAD. Moreover, the immune risk score (IRS) based on the gene expression level of the three IRGs was an independent prognostic factor for OS. Higher IRS predicted lower OS, higher mortality and worse tumor stage. With a good predictive ability [area under the ROC curve (AUC) in TCGA = 0.701, AUC in GEO = 0.722], the IRS contributed to a good risk stratification ability of the nomogram. Immunologically, the three IRGs were related to M1 macrophages and NK cell subsets in TME. Interestingly, by characterizing these immune components in situ we found that S100P is a driver for tumor cells to induce TAM migration and M2 polarization in the immunosuppressive tumor niche. We identified the key genes driving TAM migration and transformation and elucidated the immune landscape of LUAD. The data suggest that IRGs from TME have the potential to become indicators for estimating cancer prognosis and guiding individualized treatment.

Autophagy Drives Galectin-1 Secretion From Tumor-Associated Macrophages Facilitating Hepatocellular Carcinoma Progression.

Galectin-1 (Gal-1) is a secretory lectin with pro-tumor activities and is associated strongly with hepatocellular carcinoma (HCC) development. Although Gal-1 is a well-known soluble pro-tumor factor in the tumor microenvironment (TME), the secretion mode of Gal-1 is not clearly defined. On the other hand, in addition to cancer cells, Gal-1 is widely expressed in tumor stromal cells, including tumor-associated macrophages (TAMs). TAMs are a significant component of stromal cells in TME; however, their contributions in producing Gal-1 to TME are still not explored. Here we reveal that TAMs can actively secrete Gal-1 in response to stimuli of HCC cells. Gal-1 produced by TAMs leads to an increase of the systemic level of Gal-1 and HCC tumor growth in mice. Mechanistically, TLR2-dependent secretory autophagy is found to be responsible for Gal-1 secretion from TAMs. Gal-1 acts as a cargo of autophagosomes to fuse with multivesicular bodies via Rab11 and VAMP7-mediated vesicle trafficking before being secreted. This autophagy-regulated Gal-1 secretion in TAMs correlates to poor overall survival and progression-free survival rates of HCC patients. Our findings uncover the secretion mode of Gal-1 via secretory autophagy and highlight the pathological role of TAM-produced Gal-1 in HCC progression.

The distinct roles of exosomes in tumor-stroma crosstalk within gastric tumor microenvironment

Gastric cancer (GC) development is a complex process displaying polytropic cell and molecular landscape within gastric tumor microenvironment (TME). Stromal cells in TME, including fibroblasts, endothelial cells, mesenchymal stem cells, and various immune cells, support tumor growth, metastasis, and recurrence, functioning as the soil for gastric tumorigenesis. Importantly, exosomes secreted by either stromal cells or tumor cells during tumor-stroma crosstalk perform as crucial transporter of agents including RNAs and proteins for cell-cell communication in GC pathogenesis. Therefore, given the distinct roles of exosomes secreted by various cell types in GC TME, increasing evidence has indicated that exosomes present as new biomarkers for GC diagnosis and prognosis and shed light on novel approaches for GC treatment.

Drug-resistant cancer cell-derived exosomal EphA2 promotes breast cancer metastasis via the EphA2-Ephrin A1 reverse signaling

Tumor metastasis induced by drug resistance is a major challenge in successful cancer treatment. Nevertheless, the mechanisms underlying the pro-invasive and metastatic ability of drug resistance remain elusive. Exosome-mediated intercellular communications between cancer cells and stromal cells in tumor microenvironment are required for cancer initiation and progression. Recent reports have shown that communications between cancer cells also promote tumor aggression. However, little attention has been regarded on this aspect. Herein, we demonstrated that drug-resistant cell-derived exosomes promoted the invasion of sensitive breast cancer cells. Quantitative proteomic analysis showed that EphA2 was rich in exosomes from drug-resistant cells. Exosomal EphA2 conferred the invasive/metastatic phenotype transfer from drug-resistant cells to sensitive cells. Moreover, exosomal EphA2 activated ERK1/2 signaling through the ligand Ephrin A1-dependent reverse pathway rather than the forward pathway, thereby promoting breast cancer progression. Our findings indicate the key functional role of exosomal EphA2 in the transmission of aggressive phenotype between cancer cells that do not rely on direct cell–cell contact. Our study also suggests that the increase of EphA2 in drug-resistant cell-derived exosomes may be an important mechanism of chemotherapy/drug resistance-induced breast cancer progression.