FuHsi regulates rDNA transcription and promotes tumor progression.

Tumor-associated macrophages (TAMs) perform supportive roles in promoting tumor progression and metastasis. In tumor microenvironment, the phenotypes of TAMs are regulated by a variety of factors, such as cytokines, ligends and products of metabolism. Recently, Exosome-mediated transfer of miRNAs is proved to be a significant way for intercellular communications. Whether exosomal miRNAs derived from tumor cells contribute to TAMs’ phenotypes remains unclear. In this study, we aim to identify the miRNAs in exosomes transferred from tumor cells to macrophages and explore how these miRNAs regulate the TAMs phenotypes. In the beginning we transferred CY3-labled miRNA NC to 4T1 mouse breast cancer cells and then co-cultured with bone marrow-derived macrophages (BMDMs). The CY3 fluorescence could be observed in BMDMs after 48 hour, suggesting that miRNAs could be transferred from tumor cells to macrophages. Next, we performed miRNAs sequencing in either BMDM or exosomes derived from 4T1 cancer cells. We analyzed and compared the miRNAseq data by bio- informatics and found that there were 30 of the most abundant miRNAs in 4T1 exosomes, and nearly all of which were rich in BMDMs. However, it was found interestingly that miR-183-5p was extremely low in BMDMs. Furthermore, we treated BMDMs with exosomes isolated form 4T1 cell conditioned medium, and then we found importantly the miR-183-5p in BMDMs was increased significantly, while cultured with exosome-depleted 4T1 conditioned medium, the expression of miR-183-5p in BMDMs was not changed. Meanwhile, we isolated TAMs from 4T1 mouse breast tumor while spleen macrophages from normal mouse as a control. The expression of miR-183-5p in TAMs was much higher than that in spleen macrophages. Moreover, it was determined that expression of pro-inflammatory cytokine TNF and IL-6 in BMDM were increased significantly in BMDMs treated with 4T1-derived exosomes. Correspondingly, transferred miR-183-5p mimic into BMDMs, the expression of TNF and IL-6 were also increased. Finally we co-cultured 4T1 cells with BMDMs transferred with miR-183-5p, and the migration and invasion of 4T1 cells were significantly enhanced. Taken together, our study demonstrate that miR-183-5p that high expression in 4T1 exosomes can transferred into macrophages to regulated their phenotypes and promote tumor progression and metastasis in breast tumor microenvironment. Citation Format: Jian Guo, Wei Wang, Yan Liu, Huiwen He, Chen Zhang, Chong Chen, Yunping Luo. Exosome-mediated transfer of miR-183-5p from tumor cells to macrophages contributes to regulate TAMs phenotypes and promote tumor progression and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4632. doi:10.1158/1538-7445.AM2017-4632

Background: Cancer-associated fibroblasts (CAFs) promote tumor progression through extracellular matrix (ECM) remodeling and extensive communication with other cells in tumor microenvironment. However, most CAF-targeting strategies failed in clinical trials due to the heterogeneity of CAFs. Hence, we aimed to identify the cluster of tumor-promoting CAFs, elucidate their function and determine their specific membrane markers to ensure precise targeting.Methods: We integrated multiple single-cell RNA sequencing (scRNA-seq) datasets across different tumors and adjacent normal tissues to identify the tumor-promoting CAF cluster. We analyzed the origin of these CAFs by pseudotime analysis, and tried to elucidate the function of these CAFs by gene regulatory network analysis and cell-cell communication analysis. We also performed cell-type deconvolution analysis to examine the association between the proportion of these CAFs and patients’ prognosis in TCGA cancer cohorts, and validated that through IHC staining in clinical tumor tissues. In addition, we analyzed the membrane molecules in different fibroblast clusters, trying to identify the membrane molecules that were specifically expressed on these CAFs.Results: We found that COL11A1+ fibroblasts specifically exist in tumor tissues but not in normal tissues and named them cancer-specific fibroblasts (CSFs). We revealed that these CSFs were transformed from normal fibroblasts. CSFs represented a more activated CAF cluster and may promote tumor progression through the regulation on ECM remodeling and antitumor immune responses. High CSF proportion was associated with poor prognosis in bladder cancer (BCa) and lung adenocarcinoma (LUAD), and IHC staining of COL11A1 confirmed their specific expression in tumor stroma in clinical BCa samples. We also identified that CSFs specifically express the membrane molecules LRRC15, ITGA11, SPHK1 and FAP, which could distinguish CSFs from other fibroblasts.Conclusion: We identified that CSFs is a tumor specific cluster of fibroblasts, which are in active state, may promote tumor progression through the regulation on ECM remodeling and antitumor immune responses. Membrane molecules LRRC15, ITGA11, SPHK1 and FAP could be used as therapeutic targets for CSF-targeting cancer treatment.

Ferroptosis inhibits tumor progression in pancreatic cancer cells, while PITX2 is known to function as a pro-oncogenic factor in various tumor types, protecting them from ferroptosis and thereby promoting tumor progression. In this study, we sought to investigate the regulatory role of PITX2 in tumor cell ferroptosis within the context of pancreatic cancer. We conducted PITX2 knockdown experiments using lentiviral infection in two pancreatic cancer cell lines, namely PANC-1 and BxPC-3. We assessed protein expression through immunoblotting and mRNA expression through RT-PCR. To confirm PITX2 as a transcription factor for GPX4, we employed Chromatin Immunoprecipitation (ChIP) and Dual-luciferase assays. Furthermore, we used flow cytometry to measure reactive oxygen species (ROS), lipid peroxidation, and apoptosis and employed confocal microscopy to assess mitochondrial membrane potential. Additionally, electron microscopy was used to observe mitochondrial structural changes and evaluate PITX2's regulation of ferroptosis in pancreatic cancer cells. Our findings demonstrated that PITX2, functioning as a transcription factor for GPX4, promoted GPX4 expression, thereby exerting an inhibitory effect on ferroptosis in pancreatic cancer cells and consequently promoting tumor progression. Moreover, PITX2 enhanced the invasive and migratory capabilities of pancreatic cancer cells by activating the WNT signaling pathway. Knockdown of PITX2 increased ferroptosis and inhibited the proliferation of PANC-1 and BxPC-3 cells. Notably, the inhibitory effect on ferroptosis resulting from PITX2 overexpression in these cells could be countered using RSL3, an inhibitor of GPX4. Overall, our study established PITX2 as a transcriptional regulator of GPX4 that could promote tumor progression in pancreatic cancer by reducing ferroptosis. These findings suggest that PITX2 may serve as a potential therapeutic target for combating ferroptosis in pancreatic cancer.

Sprouty2 regulates proliferation and survival of multiple myeloma byinhibiting activation of the ERK1/2 pathway invitro and invivo.

Cyclooxygenase-2 (COX-2), a key enzyme in prostaglandin synthesis, is highly expressed during inflammation and cellular transformation and promotes tumor progression and angiogenesis. We have previously demonstrated that endothelial cell COX-2 is required for integrin alphaVbeta3-dependent activation of Rac-1 and Cdc-42 and for endothelial cell spreading, migration, and angiogenesis (Dormond, O., Foletti, A., Paroz, C., and Ruegg, C. (2001) Nat. Med. 7, 1041-1047; Dormond, O., Bezzi, M., Mariotti, A., and Ruegg, C. (2002) J. Biol. Chem. 277, 45838-45846). In this study, we addressed the question of whether integrin-mediated cell adhesion may regulate COX-2 expression in endothelial cells. We report that cell detachment from the substrate caused rapid degradation of COX-2 protein in human umbilical vein endothelial cells (HUVEC) independent of serum stimulation. This effect was prevented by broad inhibition of cellular proteinases and by neutralizing lysosomal activity but not by inhibiting the proteasome. HUVEC adhesion to laminin, collagen I, fibronectin, or vitronectin induced rapid COX-2 protein expression with peak levels reached within 2 h and increased COX-2-dependent prostaglandin E2 production. In contrast, nonspecific adhesion to poly-L-lysine was ineffective in inducing COX-2 expression. Furthermore, the addition of matrix proteins in solution promoted COX-2 protein expression in suspended or poly-L-lysine-attached HUVEC. Adhesion-induced COX-2 expression was strongly suppressed by pharmacological inhibition of c-Src, phosphatidylinositol 3-kinase, p38, extracellular-regulated kinase 1/2, and, to a lesser extent, protein kinase C and by the inhibition of mRNA or protein synthesis. In conclusion, this work demonstrates that integrin-mediated cell adhesion and soluble integrin ligands contribute to maintaining COX-2 steady-state levels in endothelial cells by the combined prevention of lysosomal-dependent degradation and the stimulation of mRNA synthesis involving multiple signaling pathways.

587: Cxcl14 (BRAK) Expression is Elevated in Prostate Cancer and May Promote Tumor Progression Through Inflammation and Endothelial Cell Recruitment

Ovarian cancer is the leading cause of death in women with gynecological malignancy and improvements in current treatments are needed. As with many other solid cancers, the ovarian tumor microenvironment is emerging as a key player in tumor progression and a potential therapeutic target. The tumor microenvironment contains several non-malignant cell types that are known to contribute to tumor progression and metastasis. Included in this population of non-malignant cells are several different types of immune cells, of which tumor-associated macrophages (TAMs) are the most abundant. An increasing amount of evidence is emerging to suggest that TAMs display a unique activation profile in ovarian tumors and are able to create an immunosuppressive microenvironment, allowing tumors to evade immune detection and promoting tumor progression. Therefore, an increased understanding of how these immune cells interact with tumor cells and the microenvironment will greatly benefit the development of more effective immunotherapies to treat ovarian cancer. This review focuses on the role of TAMs in the ovarian tumor microenvironment and how they promote tumor progression.

Multiple copies in T-cell malignancy 1 (MCT-1) is involved in transcription regulation and translation initiation. We have identified that MCT-1 plays important roles in cell transformation and survival, catastrophic mitosis and genomic instability. Enhanced MCT-1 activity decreases p53 promoter function, protein stability and activity, thereby overexpressing MCT-1 further promotes tumorigenicity in a p53-null background. Enhanced MCT-1 activation induces SHCs (Src homology 2 domain containing transforming proteins) that transmit EGFR signaling to extracellular-regulated kinase (ERK) and AKT pathway. Here, we identify a novel carcinoma metabolism pathway involving MCT-1-YY1-EGFR-MnSOD axis which confers oxidative resistance, changes tumor microenvironments and promotes tumor development. Inhibiting this oncogenic pathway may be a novel clinical intervention approach to prevent tumor progression and metastasis. Aims: Reactive oxygen species (ROS) promote tumor progression and metastasis, but the underlying mechanism remains unclear. We aim to investigate whether the oncogenic pathway enhances the generation of ROS, alters tumor microenvironment and potentiates metastasis. Results: We found that oncogene MCT-1 (multiple copies in T-cell malignancy 1) stimulated intracellular ROS formation and mitochondrial superoxide production in relationship with the deregulation of antioxidants and redox signaling. Enhanced MCT-1 activation induced the YY1-EGFR-MnSOD signaling cascade which prevented cells against oxidative damage and promoted tumor development. Importantly, MCT-1 overexpressing in lung cancer cells promoted tumor angiogenesis and necrosis along with increase of tumor-promoted M2 macrophages and cancer-associated myofibroblasts in stroma, which potentially provided a malignant microenvironment for tumor progression and metastasis. Conversely, restricting ROS generation and targeting YY1 suppressed the MCT-1-EGFR-MnSOD pathway and invasion ability in lung cancer cells. Clinical results confirm that MCT-1 overexpression is link to poor clinical outcomes and associates with hyper-activation of YY1, EGFR and MnSOD in patients with lung cancer. Importantly, MCT-1 protein enrichment is often identified in late stage and lymph node metastasis of lung cancer. Innovation and Conclusion: Our data reveal a previously unrecognized mechanism of the oxidative metabolism involving MCT-1-YY1-EGFR-MnSOD network which alters tumor microenvironments and promotes tumor progression and metastasis. Citation Format: Hong-Yu Tseng, Yen-An Chen, Jayu Jen, Yi-Ching Wang, Hsin-Ling Hsu. Oncogenic MCT-1 activation deregulates oxidative metabolism and promotes lung tumor progression and metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Translational Control of Cancer: A New Frontier in Cancer Biology and Therapy; 2016 Oct 27-30; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2017;77(6 Suppl):Abstract nr A30.

<div>Abstract<p>Tumor-associated and tumor-infiltrating neutrophils (TAN) and macrophages (TAM) can account for as much as 50% of the total tumor mass in invasive breast carcinomas. It is thought that tumors secrete factors that elicit a wound-repair response from TAMs and TANs and that this response inadvertently stimulates tumor progression. Oncostatin M is a pleiotropic cytokine belonging to the interleukin-6 family that is expressed by several cell types including activated human T lymphocytes, macrophages, and neutrophils. Whereas oncostatin M can inhibit the proliferation of breast cancer cells <i>in vitro</i>, recent studies suggest that oncostatin M may promote tumor progression by enhancing angiogenesis and metastasis. In addition, neutrophils can be stimulated to synthesize and rapidly release large quantities of oncostatin M. In this article, we show that human neutrophils secrete oncostatin M when cocultured with MDA-MB-231 and T47D human breast cancer cells. Neutrophils isolated from whole blood or breast cancer cells alone express little oncostatin M by immunocytochemistry and ELISA, but neutrophils express and release high levels of oncostatin M when they are cocultured with breast cancer cells. In addition, we show that granulocyte-macrophage colony-stimulating factor produced by breast cancer cells and cell-cell contact are both necessary for the release of oncostatin M from neutrophils. Importantly, neutrophil-derived oncostatin M induces vascular endothelial growth factor from breast cancer cells in coculture and increases breast cancer cell detachment and invasive capacity, suggesting that neutrophils and oncostatin M may promote tumor progression <i>in vivo</i>.</p></div>

It has been recognized that cancer is not merely a disease of tumor cells, but a disease of imbalance, in which stromal cells and tumor microenvironment play crucial roles. Extracellular matrix (ECM) as the most abundant component in tumor microenvironment can regulate tumor cell behaviors and tissue tension homeostasis. Collagen constitutes the scaffold of tumor microenvironment and affects tumor microenvironment such that it regulates ECM remodeling by collagen degradation and re-deposition, and promotes tumor infiltration, angiogenesis, invasion and migration. While collagen was traditionally regarded as a passive barrier to resist tumor cells, it is now evident that collagen is also actively involved in promoting tumor progression. Collagen changes in tumor microenvironment release biomechanical signals, which are sensed by both tumor cells and stromal cells, trigger a cascade of biological events. In this work, we discuss how collagen can be a double-edged sword in tumor progression, both inhibiting and promoting tumor progression at different stages of cancer development.

<div>Abstract<p>Tumor-associated and tumor-infiltrating neutrophils (TAN) and macrophages (TAM) can account for as much as 50% of the total tumor mass in invasive breast carcinomas. It is thought that tumors secrete factors that elicit a wound-repair response from TAMs and TANs and that this response inadvertently stimulates tumor progression. Oncostatin M is a pleiotropic cytokine belonging to the interleukin-6 family that is expressed by several cell types including activated human T lymphocytes, macrophages, and neutrophils. Whereas oncostatin M can inhibit the proliferation of breast cancer cells <i>in vitro</i>, recent studies suggest that oncostatin M may promote tumor progression by enhancing angiogenesis and metastasis. In addition, neutrophils can be stimulated to synthesize and rapidly release large quantities of oncostatin M. In this article, we show that human neutrophils secrete oncostatin M when cocultured with MDA-MB-231 and T47D human breast cancer cells. Neutrophils isolated from whole blood or breast cancer cells alone express little oncostatin M by immunocytochemistry and ELISA, but neutrophils express and release high levels of oncostatin M when they are cocultured with breast cancer cells. In addition, we show that granulocyte-macrophage colony-stimulating factor produced by breast cancer cells and cell-cell contact are both necessary for the release of oncostatin M from neutrophils. Importantly, neutrophil-derived oncostatin M induces vascular endothelial growth factor from breast cancer cells in coculture and increases breast cancer cell detachment and invasive capacity, suggesting that neutrophils and oncostatin M may promote tumor progression <i>in vivo</i>.</p></div>

Background: Amyloid precursor protein (APP) is a type I transmembrane glycoprotein that is overexpressed in various cancer types and has been reported to play key roles in promoting tumor progression. In this study, we investigated the subcellular expression, biological function, and potential therapeutic strategies targeting the ADAM10-APP axis in colorectal cancer (CRC). Methods: Single-cell RNA sequencing and spatial transcriptomic analysis were performed to elucidate the enrichment of APP expression in CRC. Liquid chromatography-mass spectrometry (LC-MS) surfaceome analysis was conducted on 14 CRC cell lines to validate APP expression on the cell surface. A tissue microarray (TMA) was used to validate the surface expression of APP. Western blotting, 3D culture, invasion and migration assays, as well as a nude mouse model, were utilized to investigate the biological function of APP. Additionally, an antibody-drug conjugate (ADC) assay targeting APP was utilized to explore its therapeutic potential in CRC. Results: Multi-omics data revealed that APP is highly expressed in CRC and is specifically enriched in epithelial cells. Through proteomic profiling of human CRC cell lines and validation in a tissue microarray consisting of 140 CRC tumors, we identified APP as significantly enriched on the cell surface. Functional studies showed that knockdown or knockout (KO) of APP in CRC cells led to marked reductions in cell proliferation, colony formation, and invasiveness, effects that were in part reversible upon the addition of soluble APP (sAPP). In xenograft models of colorectal cancer (CRC), APP-KO HCT116 tumor-bearing mice exhibited significantly reduced tumor growth and tumor initiation frequency compared to control HCT116 tumor-bearing mice. We further demonstrated that treatment of CRC cells with GI254023X, a selective ADAM10 inhibitor, increased cancer cell surface APP expression. A combination therapy of GI254023X with an APP antibody conjugated to monomethyl auristatin F (APP-ADC-MMAF) resulted in superior anti-cancer efficacy compared to either treatment alone. Conclusion: APP is highly expressed on the surface of CRC cells and promotes tumor progression, making it a potential target for ADC therapies. Inhibition of ADAM10 reduces APP cleavage and further enhances its surface expression, highlighting a promising treatment strategy for CRC. Citation Format: Rongzhang Dou, Hanwen Xu, Ricardo A. León-Letelier, Ali H. Abdel Sater, Yihui Chen, Jody Vykoukal, Makoto Kobayashi, Clemente Aguilar-Bonavides, Johannes F. Fahrmann, Hiroyuki Katayama, Samir M. Hanash. Dual targeting of amyloid precursor protein with α-secretase inhibitor and antibody-drug conjugate synergistically reduces tumor progression in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6740.

Simple SummaryAs our knowledge of cancer as a complex organ comprising tumor cells as well as surrounding cells within the microenvironment continues to grow, it is imperative to consider how the microenvironment may be supporting the cancer and promoting tumor progression. One aspect of the microenvironment that has gained significant interest over the past decade are cancer-associated fibroblasts, which have been implicated in diverse oncogenic roles including cancer invasion and metastasis, resistance to existing cancer therapeutics, angiogenesis, and tumor proliferation. The identification of cancer-associated fibroblasts and the pathways through which they promote tumor progression will allow us to target a specific subset of cells within the cancer niche in order to augment existing cancer therapies and possibly develop novel methods. In this review, we discuss the different markers that have been used to identify cancer-associated fibroblasts in various cancer contexts as potential therapeutic targets and discuss the role that cancer-associated fibroblasts play in enhancing cancer malignancy.In the era of genomic medicine, cancer treatment has become more personalized as novel therapeutic targets and pathways are identified. Research over the past decade has shown the increasing importance of how the tumor microenvironment (TME) and the extracellular matrix (ECM), which is a major structural component of the TME, regulate oncogenic functions including tumor progression, metastasis, angiogenesis, therapy resistance, and immune cell modulation, amongst others. Within the TME, cancer-associated fibroblasts (CAFs) have been identified in several systemic cancers as critical regulators of the malignant cancer phenotype. This review of the literature comprehensively profiles the roles of CAFs implicated in gastrointestinal, endocrine, head and neck, skin, genitourinary, lung, and breast cancers. The ubiquitous presence of CAFs highlights their significance as modulators of cancer progression and has led to the subsequent characterization of potential therapeutic targets, which may help advance the cancer treatment paradigm to determine the next generation of cancer therapy. The aim of this review is to provide a detailed overview of the key roles that CAFs play in the scope of systemic disease, the mechanisms by which they enhance protumoral effects, and the primary CAF-related markers that may offer potential targets for novel therapeutics.

IntroductionIn vivo, cancer cells respond to signals from the tumor microenvironment resulting in changes in expression of proteins that promote tumor progression and suppress anti-tumor immunity. This study employed an orthotopic immunocompetent model of lung cancer to define pathways that are altered in cancer cells recovered from tumors compared to cells grown in culture.MethodsStudies used four murine cell lines implanted into the lungs of syngeneic mice. Cancer cells were recovered using FACS, and transcriptional changes compared to cells grown in culture were determined by RNA-seq.ResultsChanges in interferon response, antigen presentation and cytokine signaling were observed in all tumors. In addition, we observed induction of the complement pathway. We previously demonstrated that activation of complement is critical for tumor progression in this model. Complement can play both a pro-tumorigenic role through production of anaphylatoxins, and an anti-tumorigenic role by promoting complement-mediated cell killing of cancer cells. While complement proteins are produced by the liver, expression of complement proteins by cancer cells has been described. Silencing cancer cell-specific C3 inhibited tumor growth In vivo. We hypothesized that induction of complement regulatory proteins was critical for blocking the anti-tumor effects of complement activation. Silencing complement regulatory proteins also inhibited tumor growth, with different regulatory proteins acting in a cell-specific manner.DiscussionBased on these data we propose that localized induction of complement in cancer cells is a common feature of lung tumors that promotes tumor progression, with induction of complement regulatory proteins protecting cells from complement mediated-cell killing.

Tumor-associated and tumor-infiltrating neutrophils (TAN) and macrophages (TAM) can account for as much as 50% of the total tumor mass in invasive breast carcinomas. It is thought that tumors secrete factors that elicit a wound-repair response from TAMs and TANs and that this response inadvertently stimulates tumor progression. Oncostatin M is a pleiotropic cytokine belonging to the interleukin-6 family that is expressed by several cell types including activated human T lymphocytes, macrophages, and neutrophils. Whereas oncostatin M can inhibit the proliferation of breast cancer cells in vitro, recent studies suggest that oncostatin M may promote tumor progression by enhancing angiogenesis and metastasis. In addition, neutrophils can be stimulated to synthesize and rapidly release large quantities of oncostatin M. In this article, we show that human neutrophils secrete oncostatin M when cocultured with MDA-MB-231 and T47D human breast cancer cells. Neutrophils isolated from whole blood or breast cancer cells alone express little oncostatin M by immunocytochemistry and ELISA, but neutrophils express and release high levels of oncostatin M when they are cocultured with breast cancer cells. In addition, we show that granulocyte-macrophage colony-stimulating factor produced by breast cancer cells and cell-cell contact are both necessary for the release of oncostatin M from neutrophils. Importantly, neutrophil-derived oncostatin M induces vascular endothelial growth factor from breast cancer cells in coculture and increases breast cancer cell detachment and invasive capacity, suggesting that neutrophils and oncostatin M may promote tumor progression in vivo.