Cancer Stromal Cells Research Articles

Abstract 3894: The temporal influence of the tumor microenvironment in response to checkpoint blockade

Abstract Immune checkpoint inhibition (ICI) has produced a paradigm shift in treatment across a range of cancer subtypes. However, our understanding of why only certain patients respond, as well as our ability to predict this response, is still quite limited. This is exacerbated by the complexity of the tumor microenvironment (TME), which contains cancer cells, immune cells, and stromal cells. These differing cell types can have context-dependent roles in either promoting or inhibiting anti-tumor immune responses, making it challenging to identify features which reliably correlate with patient outcome. In addition, the roles of these diverse cell types are often influenced by their location within the TME, meaning that assays without spatial information cannot fully resolve this complexity. To address these gaps, we mapped the spatial distribution and phenotype of 21 cell populations across 117 patients with metastatic triple negative breast cancer that received nivolumab (anti-PD1) through the TONIC clinical trial (NCT02499367). We collected metastatic samples prior to and during treatment to understand how anti-PD1 reshaped the TME. We also collected archival material from the original primary tumor for each patient. We generated multiplexed imaging data from these samples, identified the location and phenotype of each cell, and then quantified the spatial distribution, diversity, and functional marker status of all cell populations in the TME. We detected numerous features indicative of a productive immune response that correlated positively with clinical benefit, whereas features indicative of a suppressive microenvironment correlated negatively with clinical benefit. We observed significant temporal effects, where many pre-treatment predictive features were not predictive on-treatment; similarly, many on-treatment predictive features had no predictive power prior to treatment. Intriguingly, we found features in the original primary tumors which predicted subsequent (metastatic) response to immunotherapy. We observed substantial differences in predictive accuracy of multivariate models based on timepoint, with on-treatment samples exhibiting the best performance and primary tumor samples exhibiting the worst. Of note, we observed substantially worse predictive performance when using bulk DNA sequencing data to predict outcome from the same patients, highlighting the importance of spatial information. Taken together, we show that the features associated with a productive anti-tumor immune response are temporally structured, and differ based on what phase of response is profiled. Furthermore, using the primary tumor to assess whether metastatic TNBC patients are good candidates for ICI may miss important predictive signals. These findings shed new light on the determinants of ICI outcome, and may shape the design of subsequent trials to better understand the temporal aspects of ICI. Citation Format: Noah F. Greenwald, Iris Nederlof, Hugo Horlings, Marleen Kok, Christina Curtis, Michael Angelo. The temporal influence of the tumor microenvironment in response to checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3894.

Abstract 5565: Multiomic characterization of colorectal cancer using MICS technology reveals interaction of antigen presenting cancer associated fibroblasts and T cells

Abstract In solid tumors, the tumor microenvironment (TME) is composed of diverse cell types including cancer cells, immune cells, stromal cells, and other tissue specific cell types. The complex intercellular interactions that occur between these various cell populations determine cancer development and progression. Cancer-associated fibroblasts (CAFs) have been identified as key players in the TME, capable of promoting tumor cell growth and invasion, as well as manipulating immune responses. To better resolve potential subpopulations, spatial relationships, and signaling occurring between cell types within the TME, we performed same-section multiomic profiling of colorectal cancer (CRC) using the MACSima™ Imaging Cyclic Staining (MICS) technology. We combined a custom 40plex RNA panel with a panel of antibodies to characterize the drivers of tumorigenesis and the activation state of immune cells. FFPE CRC specimens were reviewed by a pathologist for clinical assessment and region of interest selection. Then, gene expression profiles were generated using RNAsky™ technology with each gene being detected via cyclic rounds of detection probe hybridization, image acquisition, and signal erasure. Subsequently, fluorescently labeled antibodies were applied to the same section following an equivalent acquisition process. Finally, multiomic clustering and cell population analyses were performed using MACS® iQ View software. The analysis revealed spatially separated subpopulations of CAFs. Functional characterization of cellular neighborhoods and the cell-to-cell interactions occurring within the TME showed that one of the CAF populations potentially promoted cancer cell growth while another subpopulation, resembling antigen-presenting CAFs (apCAFs), closely interacted with T cells in the TME. These findings will deepen our understanding of tumor progression in colorectal cancer and potentially other solid tumors. Citation Format: Emily Neil, Rebecca C. Hennessey, David Agorku, Dongju Park, Julia Femel, Michael DiBuono, Hanna Lafayette, Erica Lloyd, Hsinyi Lo, Alex Makrigiorgos, Shaina Lu, John Lee, Sameh Soliman, Dominic Mangiardi, Paurush Praveen, Philip Ströbel, Silvia Rüberg, Fabian Staubach, Ryan Hindman, Thomas Rothmann, Olaf Hardt, Hansueli Meyer, Tanya Wantenaar, Jinling Wang, Werner Müller, Robert Pinard, Andreas Bosio. Multiomic characterization of colorectal cancer using MICS technology reveals interaction of antigen presenting cancer associated fibroblasts and T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5565.

Abstract 5286: M2 to M1 repolarization of tumor-associated macrophages via the lysosomal effect of itraconazole

Abstract Objective: Itraconazole (ITZ), an antifungal agent, has been reported to have tumor agnostic anticancer effects. Previous reports have shown prolonged survival in patients with lung and ovarian cancer who received ITZ. The anticancer mechanisms vary depending on the cancer type and stromal cells. Based on our previous studies, we focused on tumor-associated macrophages (TAMs). Methods: Anti-tumorigenic M1 and pro-tumorigenic M2 macrophages were established from THP-1 cells and their phenotypes were determined based on morphology, cell surface antigens by Western blotting, and secreted proteins by ELISA. Bulk proteomic analysis of cell proteins was conducted using liquid chromatography-tandem mass spectrometry. The viability of CaSki cervical cancer cells was evaluated both in culture with the supernatant and co-culture with M2 macrophages after treatment with ITZ (10-5 M). Single-cell RNA sequencing (scRNA-seq) with surface labeling of M2 macrophages with and without the ITZ was performed. Using LoupeBrowser (10x Genomics, Inc.), ITZ-treated M2 macrophages were divided into two groups, one with newly emerged clusters after ITZ treatment (group 1) and the other (group 2). Differentially expressed genes between group 1 and group 2 were identified based on a two-fold and a 0.05 adjusted p value and were subjected to Reactome pathway analysis. Significant pathways were identified based on both p value < 0.05 and FDR <0.3. A triple-labeling immunofluorescence study was conducted to detect cholesterol, IL-1β, and organelles (the endoplasmic reticulum, phagosome, and lysosome). Results: ITZ changed M2 macrophages to M1-like morphology and protein expression. While co-culture with M2 macrophages promoted cancer cell proliferation, both culture with the supernatant and co-culture with ITZ-treated M2 macrophages significantly inhibited CaSki cell growth. scRNA-seq identified newly emerged clusters (group 1) among M2 macrophages following ITZ treatment. Group 1 had elevated mRNA expression of M1 markers, including IL1β, IL6, CD86, TL4, GAPDH, and RKM, compared to group 2. Group 1 expressed the CD86 and TLR4 surface antigen proteins. Pathway analysis identified 176 significant pathways including lysosome vesicle biogenesis. Immunofluorescence analysis showed that M1-like macrophages in ITZ-treated M2 macrophages had enlarged lysosomes containing cholesterol. Conclusion: ITZ repolarized THP-1 derived M2 macrophage to an M1-like phenotype. The mechanism of repolarization involves intracellular cholesterol accumulation via lysosomal dysfunction. Citation Format: Yumi Takimoto, Hiroshi Tsubamoto, Kazuko Sakata, Roze Isono-Taniguchi, Tomoko Ueda, Hiroaki Shibahara. M2 to M1 repolarization of tumor-associated macrophages via the lysosomal effect of itraconazole [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5286.

Abstract B085: Carcinoma-associated mesenchymal stem cells promote high-grade serous ovarian cancer metastasis and drive tumor heterogeneity at the metastatic site through direct mitochondrial transfer

Abstract High-grade serous ovarian cancer (HGSC) is the most common and lethal form of ovarian cancer, accounting for over 70% of ovarian cancer cases. HGSC mortality is largely driven by early and diffuse transcoelomic spread from the primary site throughout the peritoneal cavity, resulting in roughly three-quarters of cases presenting with advanced stage disease at time of diagnosis. Following detachment from the primary tumor, disseminated ovarian cancer cells are spread by the peritoneal fluid and ascites where they must adapt to their new microenvironment to survive and successfully form metastases. Crucial to this spread is the formation of multicellular aggregates containing both cancer and non-malignant stromal cells, which enhance cancer cell survival and are associated with poor clinical outcome. While most studies on HGSC multicellular aggregates have focused on ovarian cancer cells alone, the interactions between ovarian cancer cells and other non-malignant cells have yet to be fully elucidated. Prior work by our group have shown that stromal-progenitor cells, termed carcinoma-associated mesenchymal stem/stromal cells (CA-MSCs), enhance HGSC metastasis through direct cellular interaction and formation of heterocellular CA-MSC:cancer cell complexes. Here we demonstrate CA-MSCs enhance metastasis by preferentially donating their mitochondria to cancer cells with the least amount of endogenous mitochondria content (‘mito poor’ cancer cells), increasing their ability to survive and driving tumor heterogeneity at the metastatic site in vivo. Mito poor cancer cells were shown to have decreased proliferative capacity, increased sensitivity to platinum-based chemotherapy and display decreased oxidative phosphorylation (OXPHOS) compared to ‘mito rich’ cancer cells. Primary patient-derived CA-MSCs rescue this vulnerable phenotype by increasing proliferation, chemoresistance and OXPHOS in mito poor cancer cells. These findings were validated in a fully autologous system using CA-MSCs and cancer cells derived from the same patient to prevent confounding effects of cellular response to foreign organelle/DNA. Through lentiviral knockdown of the mitochondrial motor protein MIRO1 we further demonstrate mitochondrial transfer is necessary for CA-MSC-mediated rescue of mito poor cancer cells. Further, we developed a haplotype-specific quantification of mitochondrial DNA to differentiate CA-MSC from endogenous cancer cell mitochondria which was used to quantify the amount of CA-MSC mitochondrial donation and demonstrate donated mitochondria persist in cancer cells up to 14 days. Importantly, CA-MSC mitochondrial donation occurred in vivo and was associated with decreased survival in an orthotopic ovarian cancer murine model. Genomic barcoding was used to quantify tumor cell clonal heterogeneity; using this system we demonstrate CA-MSC mitochondrial donation significantly enhance tumor cell heterogeneity at the metastatic site in vivo. Collectively, we report CA-MSC mitochondrial transfer as a driver of HGSC progression, heterogeneity and metastasis. Citation Format: Leonard G. Frisbie, Catherine A. Pressimone, Roja Baruwal, Geyon L. Garcia, Zanib Javed, Claudette St. Croix, Simon Watkins, Michael Calderone, Huda I. Atiya, Nadine Hempel, Alexander Pearson, Lan G. Coffman. Carcinoma-associated mesenchymal stem cells promote high-grade serous ovarian cancer metastasis and drive tumor heterogeneity at the metastatic site through direct mitochondrial transfer [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B085.

Single cell analyses of cancer cells identified two regulatorily and functionally distinct categories in differentially expressed genes among tumor subclones

To explore the feature of cancer cells and tumor subclones, we analyzed 101,065 single-cell transcriptomes from 12 colorectal cancer (CRC) patients and 92 single cell genomes from one of these patients. We found cancer cells, endothelial cells and stromal cells in tumor tissue expressed much more genes and had stronger cell-cell interactions than their counterparts in normal tissue. We identified copy number variations (CNVs) in each cancer cell and found correlation between gene copy number and expression level in cancer cells at single cell resolution. Analysis of tumor subclones inferred by CNVs showed accumulation of mutations in each tumor subclone along lineage trajectories. We found differentially expressed genes (DEGs) between tumor subclones had two populations: DEGCNV and DEGreg. DEGCNV, showing high CNV-expression correlation and whose expression differences depend on the differences of CNV level, enriched in housekeeping genes and cell adhesion associated genes. DEGreg, showing low CNV-expression correlation and mainly in low CNV variation regions and regions without CNVs, enriched in cytokine signaling genes. Furthermore, cell-cell communication analyses showed that DEGCNV tends to involve in cell-cell contact while DEGreg tends to involve in secreted signaling, which further support that DEGCNV and DEGreg are two regulatorily and functionally distinct categories.

Extracellular vesicles and cancer stemness in hepatocellular carcinoma - is there a link?

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy, with high recurrence rates and notorious resistance to conventional chemotherapy. Cancer stemness refers to the stem-cell-like phenotype of cancer cells and has been recognized to play important roles in different aspects of hepatocarcinogenesis. Small extracellular vesicles (sEVs) are small membranous particles secreted by cells that can transfer bioactive molecules, such as nucleic acids, proteins, lipids, and metabolites, to neighboring or distant cells. Recent studies have highlighted the role of sEVs in modulating different aspects of the cancer stemness properties of HCC. Furthermore, sEVs derived from diverse cellular sources, such as cancer cells, stromal cells, and immune cells, contribute to the maintenance of the cancer stemness phenotype in HCC. Through cargo transfer, specific signaling pathways are activated within the recipient cells, thus promoting the stemness properties. Additionally, sEVs can govern the secretion of growth factors from non-cancer cells to further maintain their stemness features. Clinically, plasma sEVs may hold promise as potential biomarkers for HCC diagnosis and treatment prediction. Understanding the underlying mechanisms by which sEVs promote cancer stemness in HCC is crucial, as targeting sEV-mediated communication may offer novel strategies in treatment and improve patient outcome.

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.

The RNA m6A writer METTL3 in tumor microenvironment: emerging roles and therapeutic implications.

The tumor microenvironment (TME) is a heterogeneous ecosystem comprising cancer cells, immune cells, stromal cells, and various non-cellular components, all of which play critical roles in controlling tumor progression and response to immunotherapies. Methyltransferase-like 3 (METTL3), the core component of N 6-methyladenosine (m6A) writer, is frequently associated with abnormalities in the m6A epitranscriptome in different cancer types, impacting both cancer cells and the surrounding TME. While the impact of METTL3 on cancer cells has been extensively reviewed, its roles in TME and anti-cancer immunity have not been comprehensively summarized. This review aims to systematically summarize the functions of METTL3 in TME, particularly its effects on tumor-infiltrating immune cells. We also elaborate on the underlying m6A-dependent mechanism. Additionally, we discuss ongoing endeavors towards developing METTL3 inhibitors, as well as the potential of targeting METTL3 to bolster the efficacy of immunotherapy.

Abstract B039: Hypoxia promotes an inflammatory phenotype of fibroblasts in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is notable for its dense desmoplastic stroma, consisting of extracellular matrix, cancer-associated fibroblasts (CAFs), and immune cells. Another notable feature of the PDAC microenvironment is hypoxia, a condition of insufficient oxygen availability. Although hypoxia leads to adaptive responses in both cancer cells and stromal cells, the effects of hypoxia on the PDAC stroma and tumor-stroma interactions are not fully understood. Cancer-associated fibroblasts (CAFs) are a predominant and heterogeneous stromal cell type in PDAC, and single-cell transcriptomics of human and mouse PDAC has recently revealed a distinct CAF subpopulation, inflammatory CAFs (iCAFs). These inflammatory fibroblasts produce high levels of cytokines and chemokines in PDAC and have the potential to contribute to its immunosuppressive microenvironment and tumorigenesis. By injecting a hypoxia probe into PDAC mouse models, we recently found that iCAFs predominantly reside in hypoxic tumor regions. We also observed that the hypoxia-related gene signature is positively enriched in iCAFs in human PDAC samples. By exposing 3D cocultures of pancreatic tumor cells and fibroblasts to either hypoxia or normoxia, we demonstrated that hypoxia promotes iCAF formation via IL1ɑ secreted from tumor cells. Importantly, the presence of hypoxic fibroblasts further elevated IL1ɑ levels in tumor cells, implicating hypoxia as a modulator of bidirectional interactions between tumor cells and fibroblasts. Efforts are ongoing to understand the mechanism by which hypoxia promotes iCAF formation by modulating bidirectional interactions between tumor cells and fibroblasts in PDAC. Together, our study identifies hypoxia as a key environmental cue for inducing an iCAF phenotype, thus highlighting an instructive role of hypoxia in shaping the stromal microenvironment. Citation Format: Tenzin Ngodup, Ashley Mello. Hypoxia promotes an inflammatory phenotype of fibroblasts in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B039.

Proteolytic remodeling of 3D bioprinted tumor microenvironments

In native tissue, remodeling of the pericellular space is essential for cellular activities and is mediated by tightly regulated proteases. Protease activity is dysregulated in many diseases, including many forms of cancer. Increased proteolytic activity is directly linked to tumor invasion into stroma, metastasis, and angiogenesis as well as all other hallmarks of cancer. Here we show a strategy for 3D bioprinting of breast cancer models using well-defined protease degradable hydrogels that can facilitate exploration of the multifaceted roles of proteolytic extracellular matrix remodeling in tumor progression. We designed a set of bicyclo[6.1.0]nonyne functionalized hyaluronan (HA)-based bioinks cross-linked by azide-modified poly(ethylene glycol) (PEG) or matrix metalloproteinase (MMP) degradable azide-functionalized peptides. Bioprinted structures combining PEG and peptide-based hydrogels were proteolytically degraded with spatial selectivity, leaving non-degradable features intact. Bioprinting of tumor-mimicking microenvironments using bioinks comprising human breast cancer cells (MCF-7) and fibroblast in hydrogels with different susceptibilities to proteolytic degradation shows that MCF-7 proliferation and spheroid size were significantly increased in protease degradable hydrogel compartments, but only in the presence of fibroblasts. In the absence of fibroblasts in the stromal compartment, cancer cell proliferation was reduced and did not differ between degradable and nondegradable hydrogels. The interactions between spatially separated fibroblasts and MCF-7 cells consequently resulted in protease-mediated remodeling of the bioprinted structures and a significant increase in cancer cell spheroid size, highlighting the close interplay between cancer cells and stromal cells in the tumor microenvironment and the influence of proteases in tumor progression.

Single-cell RNA sequencing in ovarian cancer: revealing new perspectives in the tumor microenvironment.

Single-cell sequencing technology has emerged as a pivotal tool for unraveling the complexities of the ovarian tumor microenvironment (TME), which is characterized by its cellular heterogeneity and intricate cell-to-cell interactions. Ovarian cancer (OC), known for its high lethality among gynecologic malignancies, presents significant challenges in treatment and diagnosis, partly due to the complexity of its TME. The application of single-cell sequencing in ovarian cancer research has enabled the detailed characterization of gene expression profiles at the single-cell level, shedding light on the diverse cell populations within the TME, including cancer cells, stromal cells, and immune cells. This high-resolution mapping has been instrumental in understanding the roles of these cells in tumor progression, invasion, metastasis, and drug resistance. By providing insight into the signaling pathways and cell-to-cell communication mechanisms, single-cell sequencing facilitates the identification of novel therapeutic targets and the development of personalized medicine approaches. This review summarizes the advancement and application of single-cell sequencing in studying the stromal components and the broader TME in OC, highlighting its implications for improving diagnosis, treatment strategies, and understanding of the disease's underlying biology.

EL4 Murine-Lymphoma-Stromal-Cell Fusion Hybrids Observed With Multiple Distinct Morphologies in the Primary Tumor and Metastatic Organs of a Syngeneic Mouse Model.

We and others have previously shown that cell fusion plays an important role in cancer metastasis. Color coding of cancer and stromal cells with spectrally-distinct fluorescent proteins is a powerful tool, as pioneered by our laboratory to detect cell fusion. We have previously reported color-coded cell fusion between cancer cells and stromal cells in metastatic sites by using color-coded EL4 murine lymphoma cells and host mice expressing spectrally-distinct fluorescent proteins. Cell fusion occurred between cancer cells or, between cancer cells and normal cells, such as macrophages, fibroblasts, and mesenchymal stem cells. In the present study, the aim was to morphologically classify the fusion-hybrid cells observed in the primary tumor and multiple metastases EL4 formed from cells expressing red fluorescent protein (RFP) in transgenic mice expressing green fluorescent protein (GFP), in a syngeneic model. RFP-expressing EL4 murine lymphoma cells were cultured in vitro. EL4-RFP cells were harvested and injected intraperitoneally into immunocompetent transgenic C57/BL6-GFP mice to establish a syngeneic model. Two weeks later, mice were sacrificed and each organ was harvested, cultured, and observed using confocal microscopy. EL4 intraperitoneal tumors (primary) and metastases in the lung, liver, blood, and bone marrow were formed. All tumors were harvested and cultured. In all specimens, RFP-EL4 cells, GFP-stromal cells, and fused yellow-fluorescent hybrid cells were observed. The fused hybrid cells showed various morphologies. Immune cell-like round-shaped yellow-fluorescent fused cells had a tendency to decrease with time in liver metastases and circulating blood. In contrast fibroblast-like spindle-shaped yellow-fluorescent fused cells increased in the intraperitoneal primary tumor, lung metastases, and bone marrow. Cell fusion between EL4-RFP cells and GFP stromal cells occurred in primary tumors and all metastatic sites. The morphology of the fused hybrid cells varied in the primary and metastatic sites. The present results suggest that fused cancer and stromal hybrid cells of varying morphology may play an important role in cancer progression.

Mechanisms of lymphoma-stromal interactions focusing on tumor-associated macrophages, fibroblastic reticular cells, and follicular dendritic cells.

The interaction between cancer cells and stromal cells contributes to the pathogenesis of various types of tumors in the tumor microenvironment (TME). Macrophages (Mφs), a type of stromal cell, are transformed into tumor-associated Mφs (TAMs) after integrating within solid tumors. TAMs are known to interact with cancer cells and induce tumor progression. Thus, the cancer cells construct an organ-specific TME, which is advantageous for the survival of cancer cells in the TME. The density of stromal cells is known to be involved in the prognosis of patients with lymphomas. A higher density of stromal cells increases the interaction between lymphoma cells and stromal cells, promoting lymphoma progression. This review focuses on stromal cells in lymphoid tissues, such as TAMs, fibroblastic reticular cells (FRCs), and follicular dendritic cells (FDCs). This review also focuses on the signal transduction caused by stromal cells and tumor cells via factors such as cytokines. IL-10 and other cytokines secreted by TAMs activate the JAK/STAT pathway in lymphoma cells of follicular lymphoma, classic Hodgkin lymphoma, and diffuse large B-cell lymphoma. FRCs play roles in tumor promotion in follicular lymphoma and diffuse large B-cell lymphoma. Cytokines/chemokines secreted by FDCs play essential roles in lymphoma cell survival, proliferation, invasion, and migration in follicular lymphoma. In conclusion, TAMs, FRCs, and FDCs play crucial roles in the TME of lymphomas. Furthermore, histological spatial analysis revealing the positional relationship of each cell could highlight lymphoma-stromal interactions.

Immunotherapy guided precision medicine in solid tumors.

Cancer is no longer recognized as a single disease but a collection of diseases each with its defining characteristics and behavior. Even within the same cancer type, there can be substantial heterogeneity at the molecular level. Cancer cells often accumulate various genetic mutations and epigenetic alterations over time, leading to a coexistence of distinct subpopulations of cells within the tumor. This tumor heterogeneity arises not only due to clonal outgrowth of cells with genetic mutations, but also due to interactions of tumor cells with the tumor microenvironment (TME). The latter is a dynamic ecosystem that includes cancer cells, immune cells, fibroblasts, endothelial cells, stromal cells, blood vessels, and extracellular matrix components, tumor-associated macrophages and secreted molecules. The complex interplay between tumor heterogeneity and the TME makes it difficult to develop one-size-fits-all treatments and is often the cause of therapeutic failure and resistance in solid cancers. Technological advances in the post-genomic era have given us cues regarding spatial and temporal tumor heterogeneity. Armed with this knowledge, oncologists are trying to target the unique genomic, epigenetic, and molecular landscape in the tumor cell that causes its oncogenic transformation in a particular patient. This has ushered in the era of personalized precision medicine (PPM). Immunotherapy, on the other hand, involves leveraging the body's immune system to recognize and attack cancer cells and spare healthy cells from the damage induced by radiation and chemotherapy. Combining PPM and immunotherapy represents a paradigm shift in cancer treatment and has emerged as a promising treatment modality for several solid cancers. In this chapter, we summarise major types of cancer immunotherapy and discuss how they are being used for precision medicine in different solid tumors.

ADAMTS Proteases: Their Multifaceted Role in the Regulation of Cancer Metastasis.

Cancer leads to nearly 10 million deaths worldwide per year. The tumour microenvironment (TME) is fundamental for tumour growth and progression. A key component of the TME, the extracellular matrix (ECM) has recently become a focus of interest in cancer research. Dysregulation of ECM synthesis and proteolysis leads to uncontrolled tumour growth and metastasis. Matrix remodelling enzymes, secreted by cancer cells and stromal cells, modify the overall structure and organisation of ECM proteins, therefore influencing biochemical interactions, tissue integrity and tissue turnover. While A Disintegrin and Metalloproteinases (ADAMs)' and matrix metalloproteinases' role in cancer has been deeply investigated, other proteolytic enzymes, like ADAMs with thrombospondin(-like) motifs (ADAMTSs) have been gaining interest due to their roles in modulating cancer cell-ECM interactions and oncogenic signalling pathways. In this review, we will discuss the dysregulation of ADAMTSs in cancer and their roles in regulating cancer development and progression, via ECM remodelling and cell signalling modulation.

Investigating Ecological Interactions in the Tumor Microenvironment Using Joint Species Distribution Models for Point Patterns

The tumor microenvironment (TME) is a complex and dynamic ecosystem that involves interactions between different cell types, such as cancer cells, immune cells, and stromal cells. These interactions can promote or inhibit tumor growth and affect response to therapy. Multitype Gibbs point process (MGPP) models are statistical models used to study the spatial distribution and interaction of different types of objects, such as the distribution of cell types in a tissue sample. Such models are potentially useful for investigating the spatial relationships between different cell types in the tumor microenvironment, but so far studies of the TME using cell-resolution imaging have been largely limited to spatial descriptive statistics. However, MGPP models have many advantages over descriptive statistics, such as uncertainty quantification, incorporation of multiple covariates and the ability to make predictions. In this paper, we describe and apply a previously developed MGPP method, the saturated pairwise interaction Gibbs point process model, to a publicly available multiplexed imaging dataset obtained from colorectal cancer patients. Importantly, we show how these methods can be used as joint species distribution models (JSDMs) to precisely frame and answer many relevant questions related to the ecology of the tumor microenvironment.

A comprehensive review of 3D cancer models for drug screening and translational research.

The 3D cancer models fill the discovery gap of 2D cancer models and play an important role in cancer research. In addition to cancer cells, a range of other factors include the stroma, density and composition of extracellular matrix, cancer-associated immune cells (e.g., cancer-associated fibroblasts cancer cell-stroma interactions and subsequent interactions, and a number of other factors (e.g., tumor vasculature and tumor-like microenvironment in vivo) has been widely ignored in the 2D concept of culture. Despite this knowledge, the continued use of monolayer cell culture methods has led to the failure of a series of clinical trials. This review discusses the immense importance of tumor microenvironment (TME) recapitulation in cancer research, prioritizing the individual roles of TME elements in cancer histopathology. The TME provided by the 3D model fulfills the requirements of in vivo spatiotemporal arrangement, components, and is helpful in analyzing various different aspects of drug sensitivity in preclinical and clinical trials, some of which are discussed here. Furthermore, it discusses models for the co-assembly of different TME elements in vitro and focuses on their synergistic function and responsiveness as tumors. Furthermore, this review broadly describes of a handful of recently developed 3D models whose main focus is limited to drug development and their screening and/or the impact of this approach in preclinical and translational research.

The Complex Role of the Microbiome in Non-Small Cell Lung Cancer Development and Progression.

In recent years, there has been a growing interest in the relationship between microorganisms in the surrounding environment and cancer cells. While the tumor microenvironment predominantly comprises cancer cells, stromal cells, and immune cells, emerging research highlights the significant contributions of microbial cells to tumor development and progression. Although the impact of the gut microbiome on treatment response in lung cancer is well established, recent investigations indicate complex roles of lung microbiota in lung cancer. This article focuses on recent findings on the human lung microbiome and its impacts in cancer development and progression. We delve into the characteristics of the lung microbiome and its influence on lung cancer development. Additionally, we explore the characteristics of the intratumoral microbiome, the metabolic interactions between lung tumor cells, and how microorganism-produced metabolites can contribute to cancer progression. Furthermore, we provide a comprehensive review of the current literature on the lung microbiome and its implications for the metastatic potential of tumor cells. Additionally, this review discusses the potential for therapeutic modulation of the microbiome to establish lung cancer prevention strategies and optimize lung cancer treatment.

Shikonin reverses cancer-associated fibroblast-induced gemcitabine resistance in pancreatic cancer cells by suppressing monocarboxylate transporter 4-mediated reverse Warburg effect

BackgroundGemcitabine is a first-line chemotherapeutic agent for pancreatic cancer (PC); however, most patients who receive adjuvant gemcitabine rapidly develop resistance and recurrence. Cancer-associated fibroblasts (CAFs) are a crucial component of the tumor stroma that contribute to gemcitabine-resistance. There is thus an urgent need to find a novel therapeutic strategy to improve the efficacy of gemcitabine in PC cells under CAF-stimulation. PurposeTo investigate if shikonin potentiates the therapeutic effects of gemcitabine in PC cells with CAF-induced drug resistance. MethodsPC cell-stimulated fibroblasts or primary CAFs derived from PC tissue were co-cultured with PC cells to evaluate the ability of shikonin to improve the chemotherapeutic effects of gemcitabine in vitro and in vivo. Glucose uptake assay, ATP content analysis, lactate measurement, real-time PCR, immunofluorescence staining, western blot, and plasmid transfection were used to investigate the underlying mechanism. ResultsCAFs were innately resistant to gemcitabine, but shikonin suppressed the PC cell-induced transactivation and proliferation of CAFs, reversed CAF-induced resistance, and restored the therapeutic efficacy of gemcitabine in the co-culture system. In addition, CAFs underwent a reverse Warburg effect when co-cultured with PC cells, represented by enhanced aerobic glycolytic metabolism, while shikonin reduced aerobic glycolysis in CAFs by reducing their glucose uptake, ATP concentration, lactate production and secretion, and glycolytic protein expression. Regarding the mechanism underlying these sensitizing effects, shikonin suppressed monocarboxylate transporter 4 (MCT4) expression and cellular membrane translocation to inhibit aerobic glycolysis in CAFs. Overexpression of MCT4 accordingly reversed the inhibitory effects of shikonin on PC cell-induced transactivation and aerobic glycolysis in CAFs, and reduced its sensitizing effects. Furthermore, shikonin promoted the effects of gemcitabine in reducing the growth of tumors derived from PC cells and CAF co-inoculation in BALB/C mice, with no significant systemic toxicity. ConclusionThese results indicate that shikonin reduced MCT4 expression and activation, resulting in inhibition of aerobic glycolysis in CAFs and overcoming CAF-induced gemcitabine resistance in PC. Shikonin is a promising chemosensitizing phytochemical agent when used in combination with gemcitabine for PC treatment. The results suggest that disrupting the metabolic coupling between cancer cells and stromal cells might provide an attractive strategy for improving gemcitabine efficacy.

Semaphorin 6 Family—An Important Yet Overlooked Group of Signaling Proteins Involved in Cancerogenesis

According to recent evidence, some groups of semaphorins (SEMAs) have been associated with cancer progression. These proteins are able to modulate the cellular signaling of particular receptor tyrosine kinases (RTKs) via the stimulation of SEMA-specific coreceptors, namely plexins (plexin-A, -B, -C, -D) and neuropilins (Np1, Np2), which share common domains with RTKs, leading to the coactivation of the latter receptors. MET, ERBB2, VEGFR2, PFGFR, and EGFR, among others, represent acknowledged targets of semaphorins that are often associated with tumor progression or poor prognosis. In particular, higher expression of SEMA6 family proteins in cancer cells and stromal cells of the cancer niche is often associated with enhanced tumor angiogenesis, metastasis, and resistance to anticancer therapy. Notably, high SEMA6 expression in malignant tumor cells such as melanoma, pleural mesothelioma, gastric cancer, lung adenocarcinoma, and glioblastoma may serve as a prognostic biomarker of tumor progression. To date, very few studies have focused on the mechanisms of transmembrane SEMA6-driven tumor progression and its underlying interplay with RTKs within the tumor microenvironment. This review presents the growing evidence in the literature on the complex and shaping role of SEMA6 family proteins in cancer responsiveness to environmental stimuli.