Exploratory study of macrophage polarization and spatial distribution in colorectal cancer liver metastasis: a pilot study

Regulation and Function of Tumor-Associated Macrophages (TAMs) in Colorectal Cancer (CRC): The Role of the SRIF System in Macrophage Regulation

Colorectal cancer (CRC) remains the leading cause of morbidity and mortality for both men and women worldwide. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME) of solid tumors, including CRC. These macrophages are found in the pro-inflammatory M1 and anti-inflammatory M2 forms, with the latter increasingly recognized for its tumor-promoting phenotypes. Many signaling molecules and pathways, including AMPK, EGFR, STAT3/6, mTOR, NF-κB, MAPK/ERK, and HIFs, are involved in regulating TAM polarization. Consequently, researchers are investigating several potential predictive and prognostic markers, and novel TAM-based therapeutic targets, especially in combination therapies for CRC. Macrophages of the gastrointestinal tract, including the normal colon and rectum, produce growth hormone-releasing inhibitory peptide/somatostatin (SRIF/SST) and five SST receptors (SSTRs, SST1-5). While the immunosuppressive function of the SRIF system is primarily known for various tissues, its role within CRC-associated TAMs remains underexplored. This review focuses on the following three aspects of TAMs: first, the role of macrophages in the normal colon and rectum within the broader context of macrophage biology; second, the various bioactive factors and signaling pathways associated with TAM function, along with potential strategies targeting TAMs in CRC; and third, the interaction between the SRIF system and macrophages in both normal tissues and the CRC microenvironment.

ErTao decoction alleviates liver fibrosis by suppressing STING-mediated macrophages and NLRP3 inflammasome activation

BACKGROUND

Liver fibrosis (LF) is a common pathological process in the progression of multiple chronic liver diseases to cirrhosis, affecting millions of people worldwide annually. The incomplete understanding of its mechanisms has led to a lack of clinically effective therapeutic options. ErTao decoction (ETD, ), a derivative combining the components of Erchen Decoction and Taohong Siwu Decoction, is rooted in the traditional Chinese medicine theory of "phlegm-dampness-blood stasis". However, the precise mechanism by which ETD exerts its therapeutic effects in LF remains unclear.

PURPOSE

The purpose of study was to investigate the protective effect of ETD and elucidate its underlying molecular mechanism on LF.

METHODS

In this study, we employed a multifaceted approach to evaluate the effects of ETD on LF. We used H&E staining, Sirius red staining, immunofluorescence, immunohistochemical analysis, and Western blotting to assess the protective effects of ETD in a CCl4-induced fibrosis mouse model. In vitro validation was conducted using macrophages and hepatic stellate cells to further elucidate the mechanisms involved. STING-deficient mice were used to assess its regulatory effects on liver injury, inflammatory and activation through immunohistochemical staining and Western blotting. Furthermore, UHPLCHRMS detection and computer-aided drug analysis were employed to identify and validate potential effective components of ETD for responsible for its therapeutic effects in treating LF.

RESULTS

In our in vivo and in vitro experiments, we found that ETD effectively reduced collagen fiber deposition and alleviated LF pathological changes by inhibiting macrophage inflammatory activation and suppressing NLRP3 and STING signaling. Notably, STING deficiency exhibited a protective effect against liver tissue injury and inhibited inflammatory activation of hepatic macrophages in LF model mice. Additionally, comprehensive analysis of the active ingredients in ETD strongly suggested that Naringin served as a pivotal bioactive constituent within ETD responsible for modulating STING signaling.

CONCLUSIONS

Our study highlighted the protective effects of ETD on LF by inhibiting STING-mediated macrophage activation and NLRP3 inflammasome signaling. Notably, Naringin might serve as a promising novel STING inhibitor to effectively counteract the progression of LF. These findings represented significant advances in LF research and paved the way for the development of novel therapeutic strategies.

Biological Roles and Clinical Therapeutic Applications of Tumor-Associated Macrophages in Colorectal Liver Metastasis

Colorectal cancer (CRC) commonly metastasizes to the liver, and this poses a significant clinical challenge. Tumor-associated macrophages (TAMs), key players within the TME, play a significant role in promoting CRC metastasis by secreting various chemokines, growth factors, and cytokines. This review not only aims to enhance our knowledge of TAMs' functions in CRC progression and metastasis but also examines innovative therapeutic strategies to address the clinical problem of colorectal liver metastasis (CLM). By targeting TAMs, we may be able to develop more effective treatments and offer hope to patients suffering from this devastating disease.

Defining and modeling dynamic spatial heterogeneity within tumor microenvironments

Many solid tumors exhibit significant genetic, cellular, and biophysical heterogeneity which dynamically evolves during disease progression and after treatment. This constant flux in cell composition, phenotype, spatial relationships, and tissue properties poses significant challenges in accurately diagnosing and treating patients. Much of the complexity lies in unraveling the molecular changes in different tumor compartments, how they influence one another in space and time and where vulnerabilities exist that might be appropriate to target therapeutically. Recent advances in spatial profiling tools and technologies are enabling new insight into the underlying biology of complex tumors, creating a greater understanding of the intricate relationship between cell types, states, and the microenvironment. Here we reflect on some recent discoveries in this area, where the key knowledge and technology gaps lie, and the advancements in spatial measurements and in vitro models for the study of spatial intratumoral heterogeneity.

Role of Tumor-Associated Macrophages in Cervical Cancer: Integrating Classical Perspectives with Recent Technological Advances

Tumor-associated macrophages (TAMs) play a pivotal role in the tumor microenvironment, influencing cancer progression and contributing to poor prognosis. However, in cervical cancer (CC), their significance and involvement are relatively less studied than in other gynecological cancers such as ovarian and endometrial cancer. This review aims to provide an overview of TAMs, covering their origins and phenotypes and their impact on CC progression, along with major TAM-targeted therapeutic approaches. Furthermore, we advocate for the integration of cutting-edge research methodologies, such as single-cell RNA sequencing and spatial RNA sequencing, to enable in-depth and comprehensive investigations into TAMs in CC, which would be beneficial in leading to more personalized and effective immunotherapy strategies for patients with CC.