Colorectal Cancer Cancer-associated Fibroblasts Research Articles

Impact of STAT-signaling pathway on cancer-associated fibroblasts in colorectal cancer and its role in immunosuppression.

Colorectal cancer (CRC) remains one of the most commonly diagnosed and deadliest types of cancer worldwide. CRC displays a desmoplastic reaction (DR) that has been inversely associated with poor prognosis; less DR is associated with a better prognosis. This reaction generates excessive connective tissue, in which cancer-associated fibroblasts (CAFs) are critical cells that form a part of the tumor microenvironment. CAFs are directly involved in tumorigenesis through different mechanisms. However, their role in immunosuppression in CRC is not well understood, and the precise role of signal transducers and activators of transcription (STATs) in mediating CAF activity in CRC remains unclear. Among the myriad chemical and biological factors that affect CAFs, different cytokines mediate their function by activating STAT signaling pathways. Thus, the harmful effects of CAFs in favoring tumor growth and invasion may be modulated using STAT inhibitors. Here, we analyze the impact of different STATs on CAF activity and their immunoregulatory role.

M2-Type Macrophages and Cancer-Associated Fibroblasts Combine to Promote Colorectal Cancer Liver Metastases.

This research explored the association between CD163-labeled M2-type macrophages and cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) of 38 colorectal cancer (CRC) liver metastases. In addition, we investigated the correlation differences between M2-type macrophages and CAFs in the tumor microenvironments of 38 primary colorectal cancer patients with confirmed liver metastases and 946 colorectal cancer patients, as well as possible mechanisms of action between the two cells. The Immunohistochemistry (IHC) method was applied to detect the expression levels of M2-type macrophages and CAFs in the tissues of 984 cases of CRC and to analyze the correlation between M2-type macrophages and CAFs in colorectal cancer tissues. The IHC method was also applied to detect the expression levels of M2-type macrophages and CAFs in the liver metastases of 38 cases of CRC in the experimental group and to analyze the correlation between the two cells in liver metastases. 1. M2-type macrophages and CAFs expression were significantly higher in 38 primary colorectal cancer patients compared to 946 controls, and the expression of M2-type macrophages was significantly positively correlated with CAFs. 2. In 984 CRC cases, M2-type macrophages and CAFs expression levels were significantly higher in the cancer tissues than in the paired paracancerous tissues. 3. The expression levels of M2-type macrophages and CAFs in primary colorectal cancer were significantly higher in the experimental group than in colorectal cancer tissues without distant metastasis. M2-type macrophages and CAFs are involved in the development of the colorectal cancer tumor microenvironment, and their interaction influences the initiation and progression of liver metastasis in colorectal cancer. It may provide new clinical ideas for early diagnosis of CRC liver metastases and searching for immune targets.

Simultaneous Expression of CD70 and POSTN in Cancer-Associated Fibroblasts Predicts Worse Survival of Colorectal Cancer Patients.

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers worldwide, with high morbidity and mortality rates. The evidence for the tumor-supporting capacities of cancer-associated fibroblasts (CAFs) that modulate cancer cell proliferation, invasion, metastasis, and tumor immunity, including in CRC, has been attracting attention. The present study examined the expression status of CD70 and POSTN in CRC and analyzed their association with clinicopathological features and clinical outcomes. In the present study, in total 15% (40/269) and 44% (119/269) of cases exhibited CD70 and POSTN expression on CAFs, respectively. Co-expression of CD70 and POSTN was detected in 8% (21/269) of patients. Fluorescent immunohistochemistry identified the co-expression of CD70 and POSTN with FAP and PDPN, respectively. ACTA2 was not co-expressed with CD70 or POSTN in CRC CAFs. CRC with CD70+/POSTN+ status in CAFs was significantly associated with distant organ metastasis (p = 0.0020) or incomplete resection status (p = 0.0011). CD70+/POSTN+ status tended to associate with advanced pT stage (p = 0.032) or peritoneal metastasis (p = 0.0059). Multivariate Cox hazards regression analysis identified CD70+/POSTN+ status in CAFs [hazard ratio (HR) = 3.78] as a potential independent risk factor. In vitro experiments revealed the activated phenotypes of colonic fibroblasts induced by CD70 and POSTN, while migration and invasion assays identified enhanced migration and invasion of CRC cells co-cultured with CD70- and POSTN-expressing colonic fibroblasts. On the basis of our observations, CD70 and POSTN immunohistochemistry can be used in the prognostication of CRC patients. CRC CAFs may be a promising target in the treatment of CRC patients.

IL-15-secreting CAR natural killer cells directed toward the pan-cancer target CD70 eliminate both cancer cells and cancer-associated fibroblasts

BackgroundIt remains challenging to obtain positive outcomes with chimeric antigen receptor (CAR)-engineered cell therapies in solid malignancies, like colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC). A major obstacle is the lack of targetable surface antigens that are not shared by healthy tissues. CD70 emerges as interesting target, due to its stringent expression pattern in healthy tissue and its apparent role in tumor progression in a considerable amount of malignancies. Moreover, CD70 is also expressed on cancer-associated fibroblasts (CAFs), another roadblock for treatment efficacy in CRC and PDAC. We explored the therapeutic potential of CD70 as target for CAR natural killer (NK) cell therapy in CRC, PDAC, focusing on tumor cells and CAFs, and lymphoma.MethodsRNA-seq data and immunohistochemical analysis of patient samples were used to explore CD70 expression in CRC and PDAC patients. In addition, CD70-targeting CAR NK cells were developed to assess cytotoxic activity against CD70+ tumor cells and CAFs, and the effect of cytokine stimulation on their efficacy was evaluated. The in vitro functionality of CD70-CAR NK cells was investigated against a panel of tumor and CAF cell lines with varying CD70 expression. Lymphoma-bearing mice were used to validate in vivo potency of CD70-CAR NK cells. Lastly, to consider patient variability, CD70-CAR NK cells were tested on patient-derived organoids containing CAFs.ResultsIn this study, we identified CD70 as a target for tumor cells and CAFs in CRC and PDAC patients. Functional evaluation of CD70-directed CAR NK cells indicated that IL-15 stimulation is essential to obtain effective elimination of CD70+ tumor cells and CAFs, and to improve tumor burden and survival of mice bearing CD70+ tumors. Mechanistically, IL-15 stimulation resulted in improved potency of CD70-CAR NK cells by upregulating CAR expression and increasing secretion of pro-inflammatory cytokines, in a mainly autocrine or intracellular manner.ConclusionsWe disclose CD70 as an attractive target both in hematological and solid tumors. IL-15 armored CAR NK cells act as potent effectors to eliminate these CD70+ cells. They can target both tumor cells and CAFs in patients with CRC and PDAC, and potentially other desmoplastic solid tumors.

Exosomes derived from cancer-associated fibroblasts promote tumorigenesis, metastasis and chemoresistance of colorectal cancer by upregulating circ_0067557 to target Lin28

BackgroundCancer associated fibroblasts (CAFs) can remodel tumor microenvironment by secreting exosomes. This study aimed to investigate the role of exosomes derived from cancer-associated fibroblasts in colorectal cancer (CRC) progression.MethodsCircular RNA (circRNA) array was used to identify differentially expressed circRNAs in exosomes from normal fibroblasts (NFs) and CAFs, and confirmed one differentially expressed circRNA circ_0067557 by real-time PCR. The effect of circ_0067557 on proliferation, metastasis, chemoresistance and apoptosis was verified by wound heal, tranwell, CCK8, sphere-forming and flow cytometry assay.ResultsCirc_0067557 expression in exosomes from CAFs was higher than those from NFs. CAF-derived exosomes promoted the proliferation, migration, invasion and chemoresistance of CRC cells while suppressed apoptosis. Silencing of circ_0067557 inhibited malignant phenotypes of CRC cells by targeting Lin28A and Lin28B. Moreover, CAF-derived exosomes enhanced the growth of CRC xenograft tumors.ConclusionCirc_0067557/Lin28A and Lin28B signal axis may be a potential therapy target for CRC.

Targeting integrin α5 in fibroblasts potentiates colorectal cancer response to PD-L1 blockade by affecting extracellular-matrix deposition

BackgroundOne reason patients with cancer cannot benefit from immunotherapy is the lack of immune cell infiltration in tumor tissues. Cancer-associated fibroblasts (CAFs) are emerging as central players in immune regulation...

Role of cancer-associated fibroblasts in colorectal cancer and their potential as therapeutic targets

Cancer-associated fibroblasts (CAFs) are mesenchymal cells in the tumor microenvironment (TME). CAFs are the most abundant cellular components in the TME of solid tumors. They affect the progression and course of chemotherapy and radiotherapy in various types of tumors including colorectal cancer (CRC). CAFs can promote tumor proliferation, invasion, and metastasis; protect tumor cells from immune surveillance; and resist tumor cell apoptosis caused by chemotherapy, resulting in drug resistance to chemotherapy. In recent years, researchers have become increasingly interested CAF functions and have conducted extensive research. However, compared to other types of malignancies, our understanding of the interaction between CRC cells and CAFs remains limited. Therefore, we searched the relevant literature published in the past 10 years, and reviewed the origin, biological characteristics, heterogeneity, role in the TME, and potential therapeutic targets of CAFs, to aid future research on CAFs and tumors.

Disruption of retinol-mediated IL-6 expression in colon cancer-associated fibroblasts: new perspectives on the role of vitamin A metabolism

Stromal myo-/fibroblasts (MFs) account for up to 30% of lamina propria cells in the normal human colon and their number is dramatically increased in colon cancer (CRC). Fibroblasts from cancers, also known as cancer-associated fibroblasts (CAFs), differ from normal colonic MF (N-MFs) and support tumor-promoting inflammation, in part due to increased IL-6 secretion. In this editorial, we highlight recent data obtained regarding IL-6 regulation in colorectal cancer CAFs through vitamin A (retinol) metabolism, discuss current limitations in our understanding of the mechanisms leading to the CAF pro-inflammatory phenotype, and discuss potential approaches to target CAF retinoid metabolism during CRC treatment.

Role of cancer-associated fibroblasts in colorectal cancer

Role of cancer-associated fibroblasts in colorectal cancer

Role of cancer-associated fibroblasts in colorectal cancer

Role of cancer-associated fibroblasts in colorectal cancer

Exosomal miR-625-3p secreted by cancer-associated fibroblasts in colorectal cancer promotes EMT and chemotherapeutic resistance by blocking the CELF2/WWOX pathway

Migration, invasion, epithelial-mesenchymal transformation (EMT), and chemotherapeutic resistance are the leading causes of therapeutic failure in people with colorectal cancer (CRC). The migration of exosomal miRNA between cancer cells and the tumor microenvironment is directly associated with malignant behavior in cancer-associated fibroblasts (CAFs). In the context of earlier research, the purpose of the current study was to assess the role and potential mechanism of miR-625-3p released by CAFs in CRC cells. Exosomes were extracted and purified from CAFs conditioned medium by ultracentrifugation. Western blot, immunohistochemistry, CCK-8, transwell assay, H&E staining, Tunnel, real-time PCR, double luciferase assay, RNA-binding protein immunoprecipitation (RIP), and immunofluorescence double staining experiments were used to investigate the effects of CAFs-Exo and miR-625-3p on CRC cell invasion, migration, proliferation, EMT, chemotherapeutic resistance, and molecular mechanisms. The current results indicated that CAFs-Exo was directly internalized by CRC cells, and exosomal miR-625-3p derived from CAFs might promote migration, invasion, EMT and chemotherapeutic resistance in CRC cells by inhibiting the CELF2/WWOX pathway, providing a potential candidate for CRC prediction and treatment.

Loss of exosomal micro-RNA-200b-3p from hypoxia cancer-associated fibroblasts reduces sensitivity to 5-flourouracil in colorectal cancer through targeting high-mobility group box 3.

Hypoxia-mediated tumor progression is a major problem in colorectal cancer (CRC). MicroRNA (miR)-200b-3p can attenuate tumorigenesis in CRC, while exosomal miRNAs derived from cancer-associated fibroblasts (CAFs) can promote cancer progression. Nevertheless, the function of exosomal miR-200b-3p derived from CAFs in CRC remains unclear. In this study, CAFs and normal fibroblasts (NFs) were isolated from CRC and adjacent normal tissues. Next, exosomes were isolated from the supernatants of CAFs cultured under normoxia and hypoxia. Cell viability was tested using the cell counting kit-8 assay, and flow cytometry was used to assess cell apoptosis. Cell invasion and migration were evaluated using the transwell assay. Dual-luciferase was used to investigate the relationship between miR-200b-3p and high-mobility group box 3 (HMBG3). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the miR-200b-3p and HMBG3 level. Our results found that the miR-200b-3p level was sharply reduced in CRC tissues compared to adjacent normal tissues. Additionally, the miR-200b-3p level was reduced in exosomes derived from hypoxic CAFs compared to exosomes derived from CAFs under normoxia. Exosomes derived from hypoxic CAFs weakened the sensitivity of CRC cells to 5-fluorouracil (5-FU) compared to hypoxic CAFs-derived exosomes. However, hypoxic CAFs-derived exosomes with upregulated miR-200b-3p increased the sensitivity of CRC cells to 5-fluorouracil (5-FU) compared to hypoxic CAFs-derived exosomes. In addition, HMBG3 was identified as the downstream target of miR-200b-3p in CRC cells, and its overexpression partially reversed the anti-tumor effect of the miR-200b-3p agomir on CRC via the mediation of the β-catenin/c-Myc axis. Furthermore, compared to exosomes derived from normoxia CAFs, exosomes derived from hypoxic CAFs weakened the therapeutic effects of 5-FU on CRC in vivo via the upregulation of HMGB3 levels. Collectively, the loss of exosomal miR-200b-3p in hypoxia CAFs reduced the sensitivity to 5-FU in CRC by targeting HMGB3. Thus, our research outlines a novel method for the treatment of CRC.

Detection, Role and Prognostic Value of Cancer-associated Fibroblasts in Colorectal Cancer.

Cancer-associated fibroblasts (CAFs) - mesenchymal cells in the tumor stroma, play one of the leading roles in tumor progression in many different tumors, including colorectal cancer. Scientists have described many markers for CAFs, but none of them is specific. We performed immunohistochemistry tests using five antibodies (αSMA, POD, FAP, PDGFRα, PDGFRβ) to investigate CAFs in three zones of 49 colorectal adenocarcinomas: apical, central, and invasive edge. We revealed the reliable correlation between high PDGFRβ and PDGFRα value in the apical zone and deeper invasion (T3-T4) (p = 0.0281 and p = 0.0137). High αSMA level in apical zone (p = 0.0001), αSMA level in central zone (p = 0.019), POD level in apical zone (p = 0.0222), POD level in central zone (p = 0.0206) and PDGFRβ level in apical zone (p = 0.014) correlated reliably with the presence of metastasis in lymphatic nodules. For the first time, focused on the inner layer of CAF adjacent to tumor complexes. We observed that cases with inner αSMA expression were significantly more often (p = 0.023) characterized by the presence of regional lymph node metastasis compared with cases with mix of CAF markers (p = 0.007) and with cases with inner POD expression (p = 0.024). The found relationships between the level of markers and the presence of metastases indicate their clinical significance.

Multiplex fluorescent imaging of cancer-associated fibroblasts in colorectal cancer

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population in the tumor stroma and have important prognostic and clinical significance for solid tumors, including colorectal cancer. The identification of CAF presents difficulties due to the lack of a unique diagnostic marker. Detection of CAF by multiplex immunohistochemical staining and assessment of their colocalization. For multiplex IHC staining specimens of 10 colon adenocarcinomas without neoadjuvant treatment were selected. We used «OPAL 7-COLOR MANUAL IHC KIT» (Akoya Biosciences, USA) with five antibodies (FAP, PDGFRβ, CD31, POD, PCK) for staining and Mantra 2 Quantitative Pathology Imaging System (Akoya Biosciences, USA) for evaluation of results. CD31 and CAF markers (FAP, PDGFRβ, POD) are expressed fundamentally in different cells (p<0.0001) in all areas of the tumor (apical, central, invasive margin). Pairs FAP+PDGFRβ in all zones demonstrated significantly higher (p<0.0001) square of tandem staining. It shows that these markers are expressed in the same stromal cells (probably CAF). In pair FAP+POD significant colocalization (p=0.011) was detected only in apical zone. We connect this finding rather with active proliferation of population of young fibroblasts in zones of ulceration and granulations than with CAF. We evaluated co-localization of CAF markers (FAP, PDGFRβ, POD) and endothelial cells (CD31) in different zones of colorectal carcinomas. We showed colocalization of CAF markers for pairs FAP+PDGFRβ in all tumor zones and for pair FAP+POD in apical zone.

Cancer-associated fibroblasts in colorectal cancer

Cancer-associated fibroblasts in colorectal cancer

LINC01915 Facilitates the Conversion of Normal Fibroblasts into Cancer-Associated Fibroblasts Induced by Colorectal Cancer-Derived Extracellular Vesicles through the miR-92a-3p/KLF4/CH25H Axis.

Increasing long non-coding RNAs are reported to regulate the cell growth, apoptosis, and metastasis of cancer-associated fibroblasts (CAFs).This study aimed to explore how LINC01915 influences the conversion of normal fibroblasts (NFs) into CAFs in colorectal cancer (CRC). LINC01915 expression was initially measured in clinical tissue samples and in NFs and CAFs. Identification of the interaction between LINC01915, miR-92a-3p, KLF4, and CH25H was done. The effects of LINC01915, miR-92a-3p, and KLF4 on the angiogenesis, extracellular vesicle (EV) uptake by NFs, and activation of stromal cells were assessed using gain- or loss-of-function approaches. Xenograft mouse models were established to validate these in vitro findings in vivo. EVs were shown to stimulate NF proliferation, migration, and angiogenesis, as well as facilitate NF conversion into CAFs. CRC tissues and CAFs showed downregulated expression of LINC01915, which was associated with poor prognosis of patients. Moreover, employed LINC01915 inhibited tumor angiogenesis, CAF activation, and the uptake of tumor-derived EVs by NFs. Mechanistically, LINC01915 could competitively bind to miR-92a-3p and caused upregulation of the miR-92a-3p target KLF4 which, in turn, promoted the transcription of CH25H, leading to the suppressed uptake of EVs by NFs. The in vivo and in vitro experimental results showed that LINC01915 inhibited the uptake of CRC-derived EVs by NFs through the miR-92a-3p/KLF4/CH25H axis, thus arresting the angiogenesis and the conversion of NFs into CAFs and in turn prevent tumor growth. These data together supported the inhibiting role of LINC01915 in the conversion of NFs into CAFs triggered by the CRC-derived EVs and the ensuing tumor growth, which may be related to its regulation on the miR-92a-3p/KLF4/CH25H axis.

Organ Specificity and Heterogeneity of Cancer-Associated Fibroblasts in Colorectal Cancer.

Fibroblasts constitute a ubiquitous mesenchymal cell type and produce the extracellular matrix (ECM) of connective tissue, thereby providing the structural basis of various organs. Fibroblasts display differential transcriptional patterns unique to the organ of their origin and they can be activated by common stimuli such as transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) signaling. Cancer-associated fibroblasts (CAFs) reside in the cancer tissue and contribute to cancer progression by influencing cancer cell growth, invasion, angiogenesis and tumor immunity. CAFs impact on the tumor microenvironment by remodeling the ECM and secreting soluble factors such as chemokines and growth factors. Differential expression patterns of molecular markers suggest heterogeneous features of CAFs in terms of their function, pathogenic role and cellular origin. Recent studies elucidated the bimodal action of CAFs on cancer progression and suggest a subgroup of CAFs with tumor-suppressive effects. This review attempts to describe cellular features of colorectal CAFs with an emphasis on their heterogeneity and functional diversity.

The Versatile Roles of Cancer-Associated Fibroblasts in Colorectal Cancer and Therapeutic Implications.

The tumor microenvironment (TME) is populated by abundant cancer-associated fibroblasts (CAFs) that radically influence the disease progression across many cancers, including the colorectal cancer (CRC). In theory, targeting CAFs holds great potential in optimizing CRC treatment. However, attempts to translate the therapeutic benefit of CAFs into clinic practice face many obstacles, largely due to our limited understanding of the heterogeneity in their origins, functions, and mechanisms. In recent years, accumulating evidence has uncovered some cellular precursors and molecular markers of CAFs and also revealed their versatility in impacting various hallmarks of CRC, together helping us to better define the population of CAFs and also paving the way toward their future therapeutic targeting for CRC treatment. In this review, we outline the emerging concept of CAFs in CRC, with an emphasis on their origins, biomarkers, prognostic significance, as well as their functional roles and underlying mechanisms in CRC biology. At last, we discuss the prospect of harnessing CAFs as promising therapeutic targets for the treatment of patients with CRC.

αSMA+ fibroblasts suppress Lgr5+ cancer stem cells and restrain colorectal cancer progression.

The development and progression of solid tumors is dependent on cancer cell autonomous drivers and the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) in the TME possess both tumor-promoting and tumor-restraining functions. In the current study, we interrogated the role of αSMA+ CAFs in a genetic mouse model of metastatic colorectal cancer (CRC). Selective depletion of αSMA+ CAFs resulted in increased tumor invasiveness, lymph node metastasis, and reduced overall survival. Depletion of αSMA+ CAFs reduced BMP4 and increased TGFβ1 secretion from stromal cells, and was associated with increased Lgr5+ cancer stem-like cells (CSCs) and the generation of an immunosuppressive TME with increased frequency of Foxp3+ regulatory T cells and suppression of CD8+ T cells. This study demonstrates that αSMA+ CAFs in CRC exert tumor-restraining functions via BMP4/TGFβ1 paracrine signaling that serves to suppress Lgr5+ CSCs and promote anti-tumor immunity, ultimately limiting CRC progression.

Pharmacological Inhibition and Genetic Knockdown of BCL9 Modulate the Cellular Landscape of Cancer-Associated Fibroblasts in the Tumor-Immune Microenvironment of Colorectal Cancer.

Cancer-associated fibroblasts (CAFs) exert a key role in cancer progression and liver metastasis. They are activated in the tumor microenvironment (TME), but their prometastatic mechanisms are not defined. CAFs are abundant in colorectal cancer (CRC). However, it is not clear whether they are raised from local tissue-resident fibroblasts or pericryptal fibroblasts and distant fibroblast precursors, and whether they may stimulate metastasis-promoting communication. B-cell lymphoma 9/B-cell lymphoma 9-like (BCL9/BCL9L) is the key transcription cofactor of β-catenin. We studied the TME of CRC with single-cell sequencing and consequently found that Bcl9 depletion caused a pro-tumor effect of CAFs, while inhibition of abnormal activation of Wnt/β-catenin signal through Bcl9 depletion benefited T-cell–mediated antitumor immune responses. We also identified and evaluated four types of CAFs in CRC with liver metastasis. In summary, we demonstrate cell type landscape and transcription difference upon BCL9 suppression in CAFs, as well as how CAF affects cancer associated immune surveillance by inhibition of Wnt signaling. Targeting the Wnt signaling pathway via modulating CAF may be a potential therapeutic approach.