Tumor-associated macrophages recruited by periostin in intrahepatic cholangiocarcinoma stem cells

Decoding the spatiotemporal heterogeneity of tumor-associated macrophages

Tumor-associated macrophages (TAMs) are pivotal in cancer progression, influencing tumor growth, angiogenesis, and immune evasion. This review explores the spatial and temporal heterogeneity of TAMs within the tumor microenvironment (TME), highlighting their diverse subtypes, origins, and functions. Advanced technologies such as single-cell sequencing and spatial multi-omics have elucidated the intricate interactions between TAMs and other TME components, revealing the mechanisms behind their recruitment, polarization, and distribution. Key findings demonstrate that TAMs support tumor vascularization, promote epithelial-mesenchymal transition (EMT), and modulate extracellular matrix (ECM) remodeling, etc., thereby enhancing tumor invasiveness and metastasis. Understanding these complex dynamics offers new therapeutic targets for disrupting TAM-mediated pathways and overcoming drug resistance. This review underscores the potential of targeting TAMs to develop innovative cancer therapies, emphasizing the need for further research into their spatial characteristics and functional roles within the TME.

Tumor microenvironment of cancer stem cells: Perspectives on cancer stem cell targeting

There are few tumor cell subpopulations with stem cell characteristics in tumor tissue, defined as cancer stem cells (CSCs) or cancer stem-like cells (CSLCs), which can reconstruct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation. The microenvironment that CSCs depend on consists of various cellular components and corresponding medium components. Among these factors existing at a variety of levels and forms, cytokine networks and numerous signal pathways play an important role in signaling transduction. These factors promote or maintain cancer cell stemness, and participate in cancer recurrence, metastasis, and resistance. This review aims to summarize the recent molecular data concerning the multilayered relationship between CSCs and CSC-favorable microenvironments. We also discuss the therapeutic implications of targeting this synergistic interplay, hoping to give an insight into targeting cancer cell stemness for tumor therapy and prognosis.

Machine learning for identifying tumor stemness genes and developing prognostic model in gastric cancer

Gastric cancer presents a formidable challenge, marked by its debilitating nature and often dire prognosis. Emerging evidence underscores the pivotal role of tumor stem cells in exacerbating treatment resistance and fueling disease recurrence in gastric cancer. Thus, the identification of genes contributing to tumor stemness assumes paramount importance. Employing a comprehensive approach encompassing ssGSEA, WGCNA, and various machine learning algorithms, this study endeavors to delineate tumor stemness key genes (TSKGs). Subsequently, these genes were harnessed to construct a prognostic model, termed the Tumor Stemness Risk Genes Prognostic Model (TSRGPM). Through PCA, Cox regression analysis and ROC curve analysis, the efficacy of Tumor Stemness Risk Scores (TSRS) in stratifying patient risk profiles was underscored, affirming its ability as an independent prognostic indicator. Notably, the TSRS exhibited a significant correlation with lymph node metastasis in gastric cancer. Furthermore, leveraging algorithms such as CIBERSORT to dissect immune infiltration patterns revealed a notable association between TSRS and monocytes and other cell. Subsequent scrutiny of tumor stemness risk genes (TSRGs) culminated in the identification of CDC25A for detailed investigation. Bioinformatics analyses unveil CDC25A's implication in driving the malignant phenotype of tumors, with a discernible impact on cell proliferation and DNA replication in gastric cancer. Noteworthy validation through in vitro experiments corroborated the bioinformatics findings, elucidating the pivotal role of CDC25A expression in modulating tumor stemness in gastric cancer. In summation, the established and validated TSRGPM holds promise in prognostication and delineation of potential therapeutic targets, thus heralding a pivotal stride towards personalized management of this malignancy.

Single-cell RNA sequencing reveals cancer stem-like cells and dynamics in tumor microenvironment during cholangiocarcinoma progression

Cholangiocarcinoma is a malignancy of the bile ducts that is driven by activities of cancer stem-like cells and characterized by a heterogeneous tumor microenvironment. To better understand the transcriptional profiles of cancer stem-like cells and dynamics in the tumor microenvironment during the progression of cholangiocarcinoma, we performed single-cell RNA analysis on cells collected from three different timepoints of tumorigenesis in a YAP/AKT mouse model. Bulk RNA sequencing data from TCGA (The Cancer Genome Atlas program) and ICGC cohorts were used to verify and support the finding. In vitro and in vivo experiments were performed to assess the stemness of cancer stem-like cells. We identified Tm4sf1high malignant cells as cancer stem-like cells. Across timepoints of cholangiocarcinoma formation in YAP/AKT mice, we found dynamic change in cancer stem-like cell/stromal/immune cell composition. Nevertheless, the dynamic interaction among cancer stem-like cells, immune cells, and stromal cells at different timepoints was elaborated. Collectively, these data serve as a useful resource for better understanding cancer stem-like cell and malignant cell heterogeneity, stromal cell remodeling, and immune cell reprogramming. It also sheds new light on transcriptomic dynamics during cholangiocarcinoma progression at single-cell resolution.

Cancer-Associated Fibroblasts in Cholangiocarcinoma: Current Knowledge and Possible Implications for Therapy

Cholangiocarcinoma (CCA) is an aggressive neoplasia with an increasing incidence and mortality. It is characterized by a strong desmoplastic stroma surrounding cancer cells. Cancer-associated fibroblasts (CAFs) are the main cell type of CCA stroma and they have an important role in modulating cancer microenvironments. CAFs originate from multiple lines of cells and mainly consist of fibroblasts and alpha-smooth muscle actin (α-SMA) positive myofibroblast-like cells. The continuous cross-talking between CCA cells and desmoplastic stroma is permitted by CAF biochemical signals, which modulate a number of pathways. Stromal cell-derived factor-1 expression increases CAF recruitment to the tumor reactive stroma and influences apoptotic pathways. The Bcl-2 family protein enhances susceptibility to CAF apoptosis and PDGFRβ induces fibroblast migration and stimulates tumor lymphangiogenesis. Many factors related to CAFs may influence CCA prognosis. For instance, a better prognosis is associated with IL-33 expression and low stromal IL-6 (whose secretion is stimulated by microRNA). In contrast, a worst prognosis is given by the expression of PDGF-D, podoplanin, SDF-1, α-SMA high expression, and periostin. The maturity phenotype has a prognostic relevance too. New therapeutic strategies involving CAFs are currently under study. Promising results are obtained with anti-PlGF therapy, nintedanib (BIBF1120), navitoclax, IPI-926, resveratrol, and controlled hyperthermia.

Prognostic Impact of the Angiogenic Gene POSTN and Its Related Genes on Lung Adenocarcinoma

Background

The function of angiogenesis-related genes (ARGs) in lung adenocarcinoma (LUAD) remains poorly documented. This study was designed to reveal ARGs in LUAD and related networks.

Methods

We worked with sequencing data and clinical information pertaining to LUAD from public databases. ARGs were retrieved from the HALLMARK_ANGIOGENESIS gene set. Differential analysis and Kaplan–Meier (K–M) analysis were performed to authenticate the ARGs associated with LUAD. Weighted gene correlation network analysis was performed on the mining hub genes linked to the abovementioned genes, and functional enrichment analysis was done. Subsequently, Cox regression analyses were used to construct the prognostic gene. POSTN and microvessel density were detected using immunohistochemistry.

Results

POSTN, an ARG that was highly expressed in patients with LUAD and was closely associated with their weak overall survival was identified. Differentially expressed genes associated with POSTN were mainly enriched in entries related to the tubulointerstitial system, immune response, and epithelial cells. A positive correlation was demonstrated between POSTN expression and tumor microvessel density in LUAD. Subsequently, a prognostic gene signature was constructed and revealed that 4 genes may predict the survival of LUAD patients. Furthermore, the ESTIMATE and CIBERSORT analyses suggested that our risk scoring system may be implicated in altering the immune microenvironment of patients with LUAD. Finally, a ceRNA network was constructed based on the prognostic genes, and the regulatory networks were examined.

Conclusion

POSTN, a novel prognostic gene signature associated with ARGs, was constructed for the prognosis of patients with LUAD. This signature may alter the immune microenvironment by modulating the activation of the tubulointerstitial system, epithelial cells, and immune cells, ultimately affecting patient survival.

Macrophages Are a Double-Edged Sword: Molecular Crosstalk between Tumor-Associated Macrophages and Cancer Stem Cells

Cancer stem cells (CSCs) are a subset of highly tumorigenic cells in tumors. They have enhanced self-renewal properties, are usually chemo-radioresistant, and can promote tumor recurrence and metastasis. They can recruit macrophages into the tumor microenvironment and differentiate them into tumor-associated macrophages (TAMs). TAMs maintain CSC stemness and construct niches that are favorable for CSC survival. However, how CSCs and TAMs interact is not completely understood. An understanding on these mechanisms can provide additional targeting strategies for eliminating CSCs. In this review, we comprehensively summarize the reported mechanisms of crosstalk between CSCs and TAMs and update the related signaling pathways involved in tumor progression. In addition, we discuss potential therapies targeting CSC–TAM interaction, including targeting macrophage recruitment and polarization by CSCs and inhibiting the TAM-induced promotion of CSC stemness. This review also provides the perspective on the major challenge for developing potential therapeutic strategies to overcome CSC-TAM crosstalk.

Tumor microenvironment and immunology of cholangiocarcinoma

Cholangiocarcinoma (CCA), an aggressive tumor originating from both intra- and extra-hepatic biliary cells, represents an unmet need in liver oncology, as treatment remains largely unsatisfactory. A typical feature of CCA is the presence of a complex tumor microenvironment (TME) composed of neoplastic cells, a rich inflammatory infiltrate, and cancer-associated fibroblasts and desmoplastic matrix that makes it extremely chemoresistant to traditional chemotherapeutic drugs. In this review, we describe the cell populations within the TME, in particular those involved in the innate and adaptive immune response and how they interact with tumor cells and with matrix proteins. The TME is crucial for CCA to mount an immune escape response and is the battlefield where molecularly targeted therapies and immune therapy, particularly in combination, may actually prove their therapeutic value.

Macrophages and cancer stem cells: a malevolent alliance

Myeloid cells infiltrating tumors are gaining ever growing attention in the last years because their pro-tumor and immunosuppressive functions are relevant for disease progression and therapeutic responses. The functional ambiguity of tumor-associated macrophages (TAMs), mostly promoting tumor evolution, is a challenging hurdle. This is even more evident in the case of cancer stem cells (CSCs); as active participants in the specialized environment of the cancer stem cell niche, TAMs initiate a reciprocal conversation with CSCs. TAMs contribute to protect CSCs from the hostile environment (exogenous insults, toxic compounds, attacks from the immune cells), and produce several biologically active mediators that modulate crucial developmental pathways that sustain cancer cell stemness. In this review, we have focused our attention on the interaction between TAMs and CSCs; we describe how TAMs impact on CSC biology and, in turn, how CSCs exploit the tissue trophic activity of macrophages to survive and progress. Since CSCs are responsible for therapy resistance and tumor recurrence, they are important therapeutic targets. In view of the recent success in oncology obtained by stimulating the immune system, we discuss some macrophage-targeted therapeutic strategies that may also affect the CSCs and interrupt their malevolent alliance.

Potential Strategies to Improve the Effectiveness of Drug Therapy by Changing Factors Related to Tumor Microenvironment

A tumor microenvironment (TME) is composed of various cell types and extracellular components. It contains tumor cells and is nourished by a network of blood vessels. The TME not only plays a significant role in the occurrence, development, and metastasis of tumors but also has a far-reaching impact on the effect of therapeutics. Continuous interaction between tumor cells and the environment, which is mediated by their environment, may lead to drug resistance. In this review, we focus on the key cellular components of the TME and the potential strategies to improve the effectiveness of drug therapy by changing their related factors.

Prognostic impact of tumor microvessels in intrahepatic cholangiocarcinoma: association with tumor-infiltrating lymphocytes

Tumor microvessel density (MVD) is a prognostic factor for patients with intrahepatic cholangiocarcinoma (ICC). Tumor-infiltrating lymphocytes (TILs) are also key components of the tumor microenvironment that play important roles in ICC progression. This study aimed to clarify the relationships between the MVD and immune status and prognosis in patients with ICC. Immunohistochemical staining for cluster of differentiation 34 (CD34), cluster of differentiation 8 (CD8), forkhead box protein P3 (Foxp3), and programmed death-ligand 1 (PD-L1) was performed. The relationships between the MVD and clinicopathological characteristics and outcomes were analyzed. Additionally, the correlations between the MVD, CD8+ and Foxp3+ TIL counts, and PD-L1 expression were evaluated. One hundred ICC patients were classified into high (n = 50) and low (n = 50) MVD groups. The serum platelet and carbohydrate antigen 19-9 levels were higher in the low MVD group than in the high MVD group (P = 0.017 and P = 0.008, respectively). The low MVD group showed a significantly larger tumor size (P = 0.016), more frequent microvascular invasion (P = 0.001), and a higher rate of intrahepatic (P = 0.023) and lymph node (P < 0.001) metastasis than the high MVD group. Moreover, the MVD showed a high positive correlation with CD8+ TILs (r = 0.754, P < 0.001) and a negative correlation with Foxp3+ TILs (r = -0.302, P = 0.003). In contrast, no significant correlation was observed between the MVD and PD-L1 expression in cancer cells (P = 0.817). Patients with low MVDs had a significantly worse prognosis than those with high MVDs. Furthermore, multivariable analyses revealed that a low MVD influenced recurrence-free survival. A decreased intratumoral MVD might predict ICC patient outcomes. Tumor microvessels might be associated with ICC progression, possibly by altering TIL recruitment.

Liver Imaging and Data System (LI-RADS) Version 2018 and Other Imaging Features in Intrahepatic Cholangiocarcinoma in Chinese Adults with vs. without Chronic Hepatitis B Viral Infection

PURPOSE

To describe liver imaging reporting and data system (LI-RADS) version 2018 and other MRI imaging features in intrahepatic mass-forming cholangiocarcinoma (iCCA) in Chinese adults with vs. without chronic hepatitis B viral (HBV) infection.

METHODS

We retrospectively enrolled 89 patients with pathologically proven iCCA after multiphase imaging performed between 2004 and 2017 at a tertiary medical center in southern China. Based on whether patients had chronic HBV, iCCA was divided into two subgroups: HBV-positive (n = 50 patients, including 9 with cirrhosis) vs. HBV-negative (n = 39 patients, including 14 with hepatolithiasis and 25 with no identifiable risk factor for iCCA; none had cirrhosis). Two independent abdominal radiologists in consensus reviewed the largest mass in each patient to assign LI-RADS v2018 features; they also scored each observation's shape and location. Imaging features were compared using chi-square or Fisher's exact tests.

RESULTS

Most iCCAs in HBV-positive (88% (44/50)) and HBV-negative (97% (38/39)) patients had at least one LR-M feature. Compared to iCCAs in HBV-negative patients, iCCAs in HBV-positive patients were more likely to have at least one major feature of HCC (46% (23/50) vs. 8% (3/39), P < 0.001) and more likely to be smooth (42% (21/50) vs. 10% (4/39), P = 0.001). Six of 50 (12%) iCCAs in HBV-positive patients and 1/39 (3%) iCCAs in HBV-negative patients had at least one major feature of HCC without any LR-M feature.

CONCLUSIONS

In this retrospective single-center study in Chinese adults, iCCAs in HBV-positive patients were more likely to resemble HCCs than iCCAs in HBV-negative patients.

Cancer Stemness Meets Immunity: From Mechanism to Therapy

Cancer stem cells (CSCs) are self-renewing cells that facilitate tumor initiation, promote metastasis, and enhance cancer therapy resistance. Transcriptomic analyses across many cancer types have revealed a prominent association between stemness and immune signatures, potentially implying a biological interaction between such hallmark features of cancer. Emerging experimental evidence has substantiated the influence of CSCs on immune cells, including tumor-associated macrophages, myeloid-derived suppressor cells, and T cells, in the tumor microenvironment and, reciprocally, the importance of such immune cells in sustaining CSC stemness and its survival niche. This review covers the cellular and molecular mechanisms underlying the symbiotic interactions between CSCs and immune cells and how such heterotypic signaling maintains a tumor-promoting ecosystem and informs therapeutic strategies intercepting this co-dependency.

Effect of periostin silencing on Runx2, RANKL and OPG expression in osteoblasts

OBJECTIVE

Normal tooth eruption is closely related to relevant genes and the dynamic balance between osteoblasts and osteoclasts. If secretion of RANKL and OPG by osteoblasts is disordered, relevant gene deficiencies or mutations will result in serious tooth eruption disturbances, e.g., cleidocranial dysplasia (CCD). Thus, we examined changes in Runx2, RANKL, and OPG protein expression in MC3T3-E1 cells after silencing the periostin gene, thus, providing an experimental basis to study tooth eruption mechanisms.

METHODS

Based on previous research, cells were divided into two groups according to the virus number: the contrast group (NC group; pFU-GW-016 PSC53349-1) and the experimental group (KD group; LVpFU-GW-016PSC66473-1). Cells were infected with the lentiviral vector (multiplicity of infection = 100) and assessed by image cytometry 72 h after infection. After screening cells for the strongest gene silencing effect, Runx2, RANKL and OPG protein expression were detected by western blotting.

RESULTS

Based on quantitative PCR, the periostin gene silencing efficiency in the KD group was over 90% (P < 0.01). After periostin gene silencing, compared with the control group, Runx2 and RANKL expression in the KD group was reduced (P < 0.01 and P < 0.05, respectively), but OPG protein expression showed no significant change (P > 0.05). The RANKL/OPG ratios in the KD group were lower than those in the NC group after periostin gene silencing (P < 0.05).

CONCLUSIONS

Silencing periostin may reduce the expression of Runx2, suggesting that there may be a synergistic relationship between periostin and Runx2 in their effects on osteoblast differentiation, while reducing RANKL expression obviously confirms that the NF-κB (nuclear factor κB) pathway plays an important role in this process and that periostin silencing changes the underlying tendency toward bone metabolism. This method could even provide an experimental basis for using exogenous periostin protein to treat some abnormal bone metabolism diseases, as it could be used as a supplement for the treatment of tooth eruption abnormalities caused by Runx2 gene deficiencies or mutations (CCD).

Matrisome analysis of intrahepatic cholangiocarcinoma unveils a peculiar cancer-associated extracellular matrix structure

Background

Intrahepatic cholangiocarcinoma (iCCA) is a malignancy that arises from the intrahepatic biliary tree, showing high mortality rates due to its late clinical presentation and limited treatment options. iCCA is characterized by a dense, reactive desmoplastic stroma marked by a dramatic accumulation of extracellular matrix (ECM). Although recent results strongly suggest a relationship between increasing desmoplastic stroma and the enhanced malignant behaviour of iCCA, the importance of ECM proteins in the pathogenesis of iCCA still have to be addressed.

Methods

iCCA ECM fibrillar structural organization was characterized by histological analysis. ECM proteome profiles from decellularized iCCA and surrounding noncancerous tissues were analysed by nLC coupled to MALDI-TOF/TOF analysis.

Results

iCCA tissues displayed high levels of collagen fibers and low abundance of reticular and elastic fibers, suggesting stiffness and loss of polarity. The ECM proteome profiles of iCCA samples, when compared to those obtained from the surrounding noncancerous tissues showed a dismantling of the basement membrane, a reduced angiogenesis and a downregulation of oncosuppressive activity. In particular, we focused on the effects of the overexpression of collagen type III alpha 1 chain (COL3A1) in iCCA, thus providing evidences that COL3A1 promotes iCCA cells migration and is a component of tumor-associated aligned collagen.

Conclusions

Overall, this study contributes to the understanding of molecular basis underlying desmoplasia in iCCA and indicates the type III collagen as a promising therapeutic target.

Role of Cancer Stem Cells in Cholangiocarcinoma and Therapeutic Implications

Cholangiocarcinoma (CCA) is the second most common type of liver cancer, and is highly aggressive with very poor prognosis. CCA is classified into intrahepatic cholangiocarcinoma (iCCA) and extra-hepatic cholangiocarcinoma (eCCA), which is further stratified into perihilar (pCCA) and distal (dCCA). Cancer stem cells (CSCs) are a subpopulation of cancer cells capable of tumor initiation and malignant growth, and are also responsible for chemoresistance. Thus, CSCs play an important role in CCA carcinogenesis. Surface markers such as CD133, CD24, CD44, EpCAM, Sox2, CD49f, and CD117 are important for identifying and isolating CCA CSCs. CSCs are present in the tumor microenvironment (TME), termed ‘CSC niche’, where cellular components and soluble factors interact to promote tumor initiation. Epithelial-to-mesenchymal transition (EMT) is another important mechanism underlying carcinogenesis, involved in the invasiveness, metastasis and chemoresistance of cancer. It has been demonstrated that EMT plays a critical role in generating CSCs. Therapies targeting the surface markers and signaling pathways of CCA CSCs, proteins involved in TME, and immune checkpoint proteins are currently under investigation. Therefore, this review focuses on recent studies on the roles of CSCs in CCA; the possible therapeutic strategies targeting CSCs of CCA are also discussed.

The Role of Stroma in Cholangiocarcinoma: The Intriguing Interplay between Fibroblastic Component, Immune Cell Subsets and Tumor Epithelium

Cholangiocarcinoma (CCA) is a severe and mostly intractable adenocarcinoma of biliary epithelial cells. A typical feature of CCA is its highly desmoplastic microenvironment containing fibrogenic connective tissue and an abundance of immune cells (T lymphocytes, Natural Killer (NK) cells, and macrophages) infiltrating tumor epithelium. This strong desmoplasia is orchestrated by various soluble factors and signals, suggesting a critical role in shaping a tumor growth-permissive microenvironment that is responsible for CCA poor clinical outcome. Indeed stroma not only provides an abundance of factors that facilitate CCA initiation, growth and progression, but also a prejudicial impact on therapeutic outcome. This review will give an overview of tumor-stroma signaling in a microenvironment critically regulating CCA development and progression. Identification of CCA secreted factors by both the fibroblast component and immune cell subsets might provide ample opportunities for pharmacological targeting of this type of cancer.