Millimeter-scale, high-density three-dimensional constructs recapitulate hot and cold tumor microenvironment.

The Single-Cell Pathology Landscape of Diffuse Large B Cell Lymphoma

Cancer associated fibroblasts (CAFs) and tumor associated macrophages (TAMs) are among the most important and abundant players of the tumor microenvironment. CAFs as well as TAMs are known to play pivotal supportive roles in tumor growth and progression. The number of CAF or TAM cells is mostly correlated with poor prognosis. Both CAFs and TAMs are in a reciprocal communication with the tumor cells in the tumor milieu. In addition to such interactions, CAFs and TAMs are also involved in a dynamic and reciprocal interrelationship with each other. Both CAFs and TAMs are capable of altering each other’s functions. Here, the current understanding of the distinct mechanisms about the complex interplay between CAFs and TAMs are summarized. In addition, the consequences of such a mutual relationship especially for tumor progression and tumor immune evasion are highlighted, focusing on the synergistic pleiotropic effects. CAFs and TAMs are crucial components of the tumor microenvironment; thus, they may prove to be potential therapeutic targets. A better understanding of the tri-directional interactions of CAFs, TAMs and cancer cells in terms of tumor progression will pave the way for the identification of novel theranostic cues in order to better target the crucial mechanisms of carcinogenesis.

The tumor microenvironment (TME) is a dynamic ecosystem surrounding a tumor. The TME consists of various components such as cancer cells, stromal tissue, immune cells and the extracellular matrix (ECM). In particular, the interaction between cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) is a key regulator of immunosuppression in the TME, subsequently contributing to tumor progression, resistance and metastasis. CAFs stimulate TAMs to differentiate into a M2-like macrophage phenotype, supporting immune evasion and tumor growth. It has been found that reactive oxygen species (ROS) produced by NADPH oxidase (NOX) enzymes are involved in process. ROS have been reported to stimulate CAF activity and TAM differentiation, but the role of NOX in the interaction between CAF and TAM has not yet been elucidated. Herein, we aimed to investigate the role of NOX2 in M2 polarization of macrophages, especially CAF-mediated TAM differentiation, and evaluate the therapeutic potential of targeting NOX2 in the TME. In this study, we utilized THP-1 monocytic cell lines and human pancreatic CAFs (pCAFs) to examine the functional significance of NOX2. NOX2 was predominantly expressed in THP-1 cells compared to other NOX isozymes when polarized into M2-like macrophages and knockdown of NOX2 effectively inhibited M2-like polarization of THP-1-derived macrophages. In addition, knockdown of NOX2 significantly reduced the secretion of M-CSF by pCAFs. These findings suggest that NOX2 plays a crucial role in CAF-mediated M2 differentiation of macrophages. Based on these findings, we confirmed the effects of NOX2 inhibition using com-19, a selective NOX inhibiting molecule. Com-19 modulated M2 polarization of macrophages and downregulated NOX2 mRNA levels in the cells. Moreover, com-19 also significantly reduced ROS production and the secretion of cytokines/chemokines in macrophages under M-CSF-induced conditions. Importantly, the results also demonstrated that com-19 inhibited pCAF-induced M2-like polarization of THP-1. Taken together, we confirmed that CAFs and TAMs interact closely and NOX2 inhibition could be a potential therapeutic target for CAF- and TAM-mediated immunosuppression, especially for M2-polarization of macrophages in the TME. Furthermore, com-19 can provide a novel approach to overcome immunosuppressive barriers by interrupting their interaction in the TME, offering the potential for more effective combination therapies in cancer treatment. Citation Format: Hye ji Jang, Jihyun Um, Eun Sil Lee, Sung Hwan Moon, Soo Jin Lee. NOX2 plays a key role in M2 polarization of macrophages associated with cancer-associated fibroblast in tumor microenvironment [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 2238.

Background/Aim: Tumor microenvironment plays supportive roles for cancer cells of proliferating, invading and spreading systemically. Cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) are deemed to be essential constituents forming cancer-surrounding niche. However, the cross-talks between CAFs and TAMs in the settings of hepatocellular carcinoma (HCC) has yet to be deciphered. The lack of a reliable system simulating in vivo-microenvironment has been one of the obstacles hampering investigation of CAFs and TAMs. By using the newly-established model consisting of fibroblasts directly recovered from the disease liver, we aimed to clarify the mechanisms of CAFs modulating the macrophage differentiation and malignant potential of cancer cells in order to search for therapeutic targets. Methods: We enrolled three patients who underwent the resection of HCC and two who did living donor liver transplantation. From the resected or the explanted livers, fibroblasts from cancer and its adjacent tissues were separated by tissue digestion. We examined their ontogeny by the expression of fibroblast-specific markers. For the functional analyses, we examined invasiveness of HuH7 cells on matrigel and migratory response of monocytes in the presence of conditioned media (CM) from the fibroblasts. We assessed the phenotypes/function of macrophages after the differentiation from monocytes in the presence of M-CSF and the CM. We comprehensively assayed cytokine/chemokine in the CM to identify functionally-relevant factors. Results): After the culture, we established three types of fibroblasts, CAFs, cirrhotic liver fibroblasts (LCFs) and non-cancerous fibroblasts (NFs). All of these were positive for vimentin, SMA, PDGFRa and FAP (>99%), confirming that they are ontologically fibroblasts instead of being HCC, hepatocytes or biliary cells. The invasiveness of HuH7 were higher in the presence of the CAF- or LCF-CM compared to those with NF-CM. Similar superiority was observed with the CAF- or LCF-CM in the migratory ability of monocytes. In the process of macrophage differentiation, the CAF- or LCF-CM were capable of polarizing macrophages into TAM/M2 subtypes, as evidenced by their higher production of IL-10 but lesser IL-12. In the CAF- or LCM-CM, the levels of IL6, IL-8, CCL2 and GRO were higher than those in the NF-CM. Conclusion: The CAFs as well as LCFs directly recovered from the cirrhotic liver are functionally competent of driving TAM/M2 differentiation and providing malignant potential to cancer cells, thereby tuning the microenvironment favoring HCC development. Citation Format: Yohei Mano, Tatsuya Kanto, Hirotaka Shoji, Schiyo Yoshio, Masaya Sugiyama, Yosuke Osawa, Kiminori Kimura, Ken Shirabe, Yoshihiko Maehara, Masashi Mizokami. Cancer-associated or cirrhosis fibroblasts recovered from hepatocellular carcinoma promote macrophages and cancer cells to progressive phenotype. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3354. doi:10.1158/1538-7445.AM2015-3354

Gastric cancer remains a significant global health challenge due to its high incidence and mortality, and limited treatment options in advanced stages. Notably, gastric cancer exhibits a complex tumor microenvironment (TME) with substantial cellular and spatial heterogeneity, which profoundly impacts disease pathogenesis and therapeutic resistance. Genetic mutations and chronic inflammation contribute to its development by promoting abnormal cell proliferation and creating an immunosuppressive TME. The TME comprises various cellular and acellular components—including tumor-infiltrating lymphocytes, myeloid lineage cells such as tumor-associated macrophages and myeloid-derived suppressor cells, cancer-associated fibroblasts, extracellular matrix, and peripheral nerves—that interact with cancer cells, influencing tumor initiation, progression, immune evasion, and resistance to therapy. These elements modulate immune responses, remodel the extracellular matrix, and facilitate tumor growth and metastasis, thereby adding to the complexity of the TME. Moreover, the TME plays a critical role in therapeutic resistance through mechanisms involving angiogenesis, fibrosis, and metabolic reprogramming. Understanding the dynamic interactions within the TME offers opportunities to develop novel therapeutic strategies. Emerging approaches targeting the TME—including modulation of immune components, inhibition of fibrosis, normalization of angiogenesis, and disruption of metabolic pathways—hold promise in overcoming therapeutic resistance. Advances in technologies such as single-cell sequencing and spatial transcriptomics further enhance our understanding of TME heterogeneity, paving the way for personalized medicine in gastric cancer treatment. This review summarized the current knowledge of the cellular and molecular composition of the TME of gastric cancer, its role in disease pathogenesis and therapy resistance, and explores potential therapeutic strategies targeting TME components.

The colony-stimulating factor 1 receptor (CSF-1R) plays a pivotal role in orchestrating cellular interactions within the tumor microenvironment (TME). Although the CSF-1R has been extensively studied in myeloid cells, the expression of this receptor and its emerging role in other cell types in the TME need to be further analyzed. This review explores the multifaceted functions of the CSF-1R across various TME cellular populations, including tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), cancer-associated fibroblasts (CAFs), endothelial cells (ECs), and cancer stem cells (CSCs). The activation of the CSF-1R by its ligands, colony-stimulating factor 1 (CSF-1) and Interleukin-34 (IL-34), regulates TAM polarization towards an immunosuppressive M2 phenotype, promoting tumor progression and immune evasion. Similarly, CSF-1R signaling influences MDSCs to exert immunosuppressive functions, hindering anti-tumor immunity. In DCs, the CSF-1R alters antigen-presenting capabilities, compromising immune surveillance against cancer cells. CSF-1R expression in CAFs and ECs regulates immune modulation, angiogenesis, and immune cell trafficking within the TME, fostering a pro-tumorigenic milieu. Notably, the CSF-1R in CSCs contributes to tumor aggressiveness and therapeutic resistance through interactions with TAMs and the modulation of stemness features. Understanding the diverse roles of the CSF-1R in the TME underscores its potential as a therapeutic target for cancer treatment, aiming at disrupting pro-tumorigenic cellular crosstalk and enhancing anti-tumor immune responses.

Introduction: High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecological malignancy and accounts for ~70% of tumor recurrences after standard chemotherapy and immunotherapy. Ovarian tumor microenvironment (TME) is undeniably complex which presents considerable challenge in understanding the immunotherapy treatment responses. Our previous study has revealed that Oncostatin M receptor (OSMR) is highly expressed in ovarian cancer cells and cancer associated fibroblasts (CAFs), whereas its ligand OSM is predominantly expressed in tumor associated macrophages (TAMs). This study aims to investigate how the OSM-OSMR paracrine signaling between tumor cells, CAFs and TAMs reprograms the TME to influence therapeutic responses in ovarian cancer. Methods: We employed a 3D-3-cell co-culture method in vitro to understand how OSM/OSMR signaling modulates the interactions between ovarian cancer cells, CAFs and TAMs, that can impact therapy response of cisplatin resistant cancer cells in the ovarian TME. We performed RNA sequencing to study the differential gene signatures of each cell component in a 3-cell co-culture with their monolayer counterparts. This system was also challenged with chemotherapy-cisplatin and immunotherapy such as our newly developed anti-OSMR monoclonal antibodies to assess the therapy response of each cell component. Results: Using single-cell and single-nuclear RNA seq dataset analyses of 17 human HGSOC patient ascites, we found that CAFs and TAMs are the predominant stromal or immune cell population enriched in ovarian cancer tissues. Using immunofluorescence, we identified that enrichment of CAFs along with extracellular matrix proteins surrounding tumor cells as an indication of heavily desmoplastic tumors. Using tumor-infiltrating immune cells dataset-TIMER, we found that high OSMR in cancer cells or CAFs along with high OSM in TAMs are associated with poor survival in ovarian cancer patients. Further, RNA sequencing data of 3-cell coculture models revealed an invasive, desmoplastic and immune-suppressive gene signature compared to independent culture conditions. Notably, CAFs and ovarian cancer cells co-cultured with TAMs exhibited an improved activation of JAK/STAT3 and PI3K-AKT oncogenic pathways for chemoresistance in ovarian cancer cells. Conclusions: Our preliminary findings uncovered a potential mechanism of action of OSM-OSMR signaling in reprogramming ovarian cancer cells and stromal fibroblasts in ovarian cancer TME. Importantly, we highlight the importance of crosstalk between CAFs, ovarian cancer cells and TAMs for harnessing OSM/OSMR signaling for chemoresistance in cancer cells. Our findings also demonstrated the potential of anti-OSMR antibody therapy to target cancer cells and CAFs in the tumor microenvironment for abrogating desmoplasia; thus, improving chemosensitivity. Citation Format: Anjali Geethadevi, Shirng-Wern Tsaih, Ajay Nair, Zhiqiang Ku, Ishaque Pulikkal Kadamberi, Deepak Parashar, Prachi Gupta, Sudhir Kumar, Jasmine George, Sonam Mittal, William Bradley, Robert F. Schwabe, Zhiqiang An, Ningyan Zhang, Sunila Pradeep, Pradeep Chaluvally Raghavan. Oncostatin m receptor signaling reprograms tumor microenvironment for chemoresistance. [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 3653.

Pancreatic ductal adenocarcinoma (PDAC) remains a clinically challenging cancer, mainly due to limited therapeutic options and the presence of a highly prominent tumor microenvironment (TME), facilitating tumor progression. The TME is predominated by heterogeneous populations of cancer-associated fibroblasts (CAFs) and tumor associated macrophages (TAMs), in constant communication with each other and with tumor cells, influencing many tumoral abilities such as therapeutic resistance. However how the crosstalk between CAFs and macrophages evolves following chemotherapeutic treatment remains poorly understood, limiting our capacity to halt therapeutic resistance. We combined biological characterization of macrophages indirectly cocultured with human PDAC CAFs, under FOLFIRINOX treatment, with mRNAseq analyses of such macrophages and evaluated the relevance of the specific gene expression signature in a large series of primary PDAC patients to search for correlation with overall survival (OS) after FOLFIRINOX chemotherapy. Firstly, we demonstrated that CAFs polarize naïve and M1 macrophages towards an M2-like phenotype with a specific increase of CD200R and CD209 M2 markers. Then, we demonstrated that CAFs counteract the pro-inflammatory phenotype induced by the FOLFIRINOX on Macrophages. Indeed, we highlighted that, under FOLFIRINOX, CAFs limit the FOLFIRINOX-induced cell death of macrophages and further reinforce their M2 phenotype as well as their immunosuppressive impact through specific chemokines production. Finally, we revealed that under FOLFIRINOX CAFs drive a specific macrophage gene expression signature involving SELENOP and GOS2 that correlates with shortened OS in FOLFIRINOX-treated PDAC patients. Our study provides insight into the complex interactions between TME cells under FOLFIRINOX treatment. It suggests potential novel candidates that could be used as therapeutic targets in combination with FOLFIRINOX to prevent and alleviate TME influx on therapeutic resistance as well as biomarkers to predict FOLFIRINOX response in PDAC patients. Video Abstract.

Cancer-associated fibroblasts (CAFs) play pivotal roles in solid tumor initiation, growth, and immune evasion. However, the optimal biomimetic modeling conditions remain elusive. In this study, we investigated the effects of 2D and 3D culturing conditions on human primary CAFs integrated into a modular tumor microenvironment (TME). Using single-nucleus RNA sequencing (snRNAseq) and Proteomics' Proximity Extension Assays, we characterized CAF transcriptomic profiles and cytokine levels. Remarkably, when cultured in 2D, CAFs exhibited a myofibroblast (myCAF) subtype, whereas in 3D tumor spheroid cultures, CAFs displayed a more inflammatory (iCAF) pathological state. By integrating single-cell gene expression data with functional interrogations of critical TME-related processes [natural killer (NK)-mediated tumor killing, monocyte migration, and macrophage differentiation], we were able to reconcile form with function. In 3D TME spheroid models, CAFs enhance cancer cell growth and immunologically shield cells from NK cell-mediated cytotoxicity, in striking contrast with their 2D TME counterparts. Notably, 3D CAF-secreted proteins manifest a more immunosuppressive profile by enhancing monocyte transendothelial migration and differentiation into M2-like tumor-associated macrophages (TAMs). Our findings reveal a more immunosuppressive and clinically relevant desmoplastic TME model that can be employed in industrial drug discovery campaigns to expand the cellular target range of chemotherapeutics.

Cancer-associated fibroblasts (CAFs) play pivotal roles in solid tumor initiation, growth, and immune evasion. However, the optimal biomimetic modeling conditions remain elusive. In this study, we investigated the effects of 2D and 3D culturing conditions on human primary CAFs integrated into a modular tumor microenvironment (TME). Using single-nucleus RNA sequencing (snRNAseq) and Proteomics’ Proximity Extension Assays, we characterized CAF transcriptomic profiles and cytokine levels. Remarkably, when cultured in 2D, CAFs exhibited a myofibroblast (myCAF) subtype, whereas in 3D tumor spheroid cultures, CAFs displayed a more inflammatory (iCAF) pathological state. By integrating single-cell gene expression data with functional interrogations of critical TME-related processes [natural killer (NK)-mediated tumor killing, monocyte migration, and macrophage differentiation], we were able to reconcile form with function. In 3D TME spheroid models, CAFs enhance cancer cell growth and immunologically shield cells from NK cell-mediated cytotoxicity, in striking contrast with their 2D TME counterparts. Notably, 3D CAF-secreted proteins manifest a more immunosuppressive profile by enhancing monocyte transendothelial migration and differentiation into M2-like tumor-associated macrophages (TAMs). Our findings reveal a more immunosuppressive and clinically relevant desmoplastic TME model that can be employed in industrial drug discovery campaigns to expand the cellular target range of chemotherapeutics.

Background: ILC exhibits unique tumor microenvironment (TME) characteristics with abundant stroma and immune evasion. TAMs and CAFs are critical non-lymphoid TME components modulating immune response and progression. We aimed to compare macrophage polarization and CAF subtypes in ILC vs NST (previously known as invasive ductal carcinoma or IDC) using cellular deconvolution platform to generate large-scale transcriptomic data, and to correlate these profiles with immunotherapeutic targets, identifying potential mechanisms of immune evasion and therapeutic opportunities. Methods: 617 breast cancer samples were reviewed by central pathologist for confirmation of histologic diagnosis of ILC or NST. Based on transcriptomic results, they were subsequently classified as histomolecular ILC (hmILC) based on CDH1 inactivation/low expression; or histomolecular NST (hmNST). We analyzed bulk RNA-seq from 126 hmILC (105 Luminal, 21 non-Luminal) and 491 hmNST tumors (274 Luminal, 217 non-Luminal). The Cancer Genome Atlas (TCGA) cohort served as independent validation set. TME composition was determined using Kassandra deconvolution algorithm, quantifying M1/M2 macrophages and CAF subtypes (inflammatory-iCAF, myofibroblastic-myCAF, perivascular-like-PVL). Results: In the discovery set, predicted proportions of macrophage and CAF cell populations were assessed in the experimental cohort across molecularly defined breast cancer groups. Among Luminal hmILC tumors, median proportions were as follows: Macrophages M2 - 0.04, Macrophages M1 - 0.02, iCAF - 0.15, myCAF - 0.07, and PVL - 0.03. In Luminal hmNST tumors, values were comparable: Macrophages M2 - 0.05, Macrophages M1 - 0.03, iCAF - 0.14, myCAF - 0.06, and PVL - 0.02. In the non-Luminal subset, hmILC showed Macrophages M2 and M1 proportions of 0.05 and 0.03, respectively, with iCAF - 0.10, myCAF - 0.03, and PVL - 0.04, whereas hmNST displayed values of 0.05 (Macrophages M2), 0.03 (Macrophages M1), 0.13 (iCAF), 0.05 (myCAF), and 0.02 (PVL). The TCGA validation set showed similar trends to the discovery set; the only statistically significant observation across both cohorts was a modest enrichment of PVL cells in Luminal hmILC compared to Luminal hmNST tumors (p < 0.05, U-test). Conclusions: This large-scale comparative analysis reveals that hmILC harbors an immunosuppressive, stromal-rich TME similar to that of hmNST, characterized by TAM accumulation and FAP^+ myCAF dominance and an equal distribution of M1/M2-polarization ratio. These findings suggest that multiple immune evasion mechanisms are present in ILC, including TAM-mediated suppression. CAF-driven barriers in ILC may contribute to poor immune cell penetration, warranting investigation into CAF-driven modulation and drug delivery. Citation Format: J. Mouabbi, P. pohlmann, B. Lim, R. A. Mukhtar, D. Grachev, B. Baranov, C. Chalabyan, D. Goncharova, P. Turova, K. Chernyshov, V. Kushnarev, F. Paradiso, J. Litton, R. Layman, F. Meric-Bernstam, J. Rodon. Tumor-associated macrophage (TAMs) and cancer-associated fibroblasts (CAFs) profiles in invasive lobular carcinoma (ILC) vs no special type (NST) [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS2-10-30.

Metabolic adaptation in colorectal cancer microenvironment: Focus on cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs).

Background The tumor microenvironment (TME) plays integral roles in prostate cancer progression and therapeutic resistance. The development of effective TME-targeted therapies is limited by current technologies which are insufficient to replicate or analyze this complex environment. To address these challenges, we have developed a microfluidic cell culture platform known as STACKS, which permits co-culture of up to 6 patient-derived cell populations as well as compartmentalized, multiplexed analysis of gene expression, cell signaling, and matrix remodeling. We have focused on investigation of tumor-associated macrophages (TAMs), which are traditionally classified as M2 (tumor-supportive) or M1 (tumor-destructive) and are high value therapeutic targets with roles in prostate cancer growth, metastasis, survival, and therapeutic resistance. Methods Cell line (THP-1) and patient-derived monocytes were differentiated into macrophages within the STACKs device and polarized to either a M1 or M2 state or left unpolarized. Unpolarized macrophages were cultured with androgen dependent (LNCaP) and independent (DU145,C4-2B) prostate tumor lines and cancer-associated fibroblasts (CAFs) derived from patient biopsies. Cells were cultured on 2D surfaces as well as within 3D matrix environments. Individual cell populations were isolated and analyzed for RNA, protein, and secretory factor expression. Results We report that M2 (CCL18, MRC1) as well as M1 (CXCL10, CXCL11) associated genes were more highly upregulated in THP-1s cultured with C4-2Bs than with LNCaPs. Select M1 and M2 genes (CXCL10 and CCL18) were also more highly expressed in THP-1s cultured with CAFs than with DU145s. While IL-10 expression was higher in THP-1s in co-culture with LNCaPs than with C4-2Bs on a 2D surface, the opposite was true when THP-1s were cultured within a 3D collagen I matrix. Conclusions Within a microscale co-culture environment, we have demonstrated that macrophage gene expression is influenced by androgen dependent and independent tumor cells, stromal cells, and the structural microenvironment. Expression of certain genes, such as IL-10, was strongly dependent on the integration of multiple TME signals, such as paracrine tumor factors and cell-matrix interactions. Additionally, while macrophages are traditionally thought to polarize either towards a M1 or a M2 state, there was concomitant elevation of both M1 and M2 genes with C4-2B and CAF co-culture. These findings highlight the complexity of macrophage polarization within the TME and represent potential therapeutic targets. We will continue to build on this data through 2D and 3D multi-culture of macrophages with tumor, stromal, and immune cells to target pathways involved in TAM polarization, tumor promotion, and therapeutic resistance. Citation Format: David Kosoff, Jiaquan Yu, Jennifer L. Schehr, David J. Beebe, Joshua M. Lang. Microscale engineering of the tumor microenvironment for therapeutic targeting of tumor-associated macrophages in prostate cancer [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 4922. doi:10.1158/1538-7445.AM2017-4922

BackgroundLeukemic inhibitory factor (LIF) is an IL-6 family member which has pleiotropic effects on tumour, stromal and immune cells. LIF can alter macrophage phenotype and chemokine release in the TME,...

Ovarian cancer is the deadliest gynecologic cancer, mainly because it is often diagnosed late and resists standard treatments. The tumor microenvironment (TME) plays a major role in disease progression and therapy failure. Two key components of the TME, cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), create conditions that facilitate tumor growth and immune evasion. CAFs are highly diverse and originate from sources like fibroblasts and stem cells. They support cancer by remodeling the extracellular matrix, promoting angiogenesis, and releasing cytokines and growth factors that aid tumor survival. TAMs, which are usually in an M2 state, also promote metastasis and suppress immune responses by secreting immunosuppressive molecules. Together, CAFs and TAMs interact with cancer cells to activate pathways such as the TGF-β, IL-6, and PI3K/AKT pathways, which drive resistance to therapy. New treatments aim to block these interactions by targeting CAFs and TAMs through depletion, reprogramming, or pathway inhibition, often combined with immunotherapy. Advances such as single-cell sequencing and spatial transcriptomics now enable more precise identification of CAF and TAM subtypes, enabling more targeted therapies. This review summarizes their roles in epithelial ovarian cancer and explores how targeting these cells could improve outcomes.