The CCL2-CCR2 Axis in Lymph Node Metastasis From Oral Squamous Cell Carcinoma: An Immunohistochemical Study

Biomarkers of lymph node metastasis in colorectal cancer: update

Colorectal cancer (CRC) ranks as the second leading cause of cancer-related deaths globally, trailing only behind lung cancer, and stands as the third most prevalent malignant tumor, following lung and breast cancers. The primary cause of mortality in colorectal cancer (CRC) stems from distant metastasis. Among the various routes of metastasis in CRC, lymph node metastasis predominates, serving as a pivotal factor in both prognostication and treatment decisions for patients. This intricate cascade of events involves multifaceted molecular mechanisms, highlighting the complexity underlying lymph node metastasis in CRC. The cytokines or proteins involved in lymph node metastasis may represent the most promising lymph node metastasis markers for clinical use. In this review, we aim to consolidate the current understanding of the mechanisms and pathophysiology underlying lymph node metastasis in colorectal cancer (CRC), drawing upon insights from the most recent literatures. We also provide an overview of the latest advancements in comprehending the molecular underpinnings of lymph node metastasis in CRC, along with the potential of innovative targeted therapies. These advancements hold promise for enhancing the prognosis of CRC patients by addressing the challenges posed by lymph node metastasis.

MRI Detection of Lymph Node Metastasis through Molecular Targeting of C-C Chemokine Receptor Type 2 and Monocyte Hitchhiking

Biopsy is the clinical standard for diagnosing lymph node (LN) metastasis, but it is invasive and poses significant risk to patient health. Magnetic resonance imaging (MRI) has been utilized as a noninvasive alternative but is limited by low sensitivity, with only ∼35% of LN metastases detected, as clinical contrast agents cannot discriminate between healthy and metastatic LNs due to nonspecific accumulation. Nanoparticles targeted to the C-C chemokine receptor 2 (CCR2), a biomarker highly expressed in metastatic LNs, have the potential to guide the delivery of contrast agents, improving the sensitivity of MRI. Additionally, cancer cells in metastatic LNs produce monocyte chemotactic protein 1 (MCP1), which binds to CCR2+ inflammatory monocytes and stimulates their migration. Thus, the molecular targeting of CCR2 may enable nanoparticle hitchhiking onto monocytes, providing an additional mechanism for metastatic LN targeting and early detection. Hence, we developed micelles incorporating gadolinium (Gd) and peptides derived from the CCR2-binding motif of MCP1 (MCP1-Gd) and evaluated the potential of MCP1-Gd to detect LN metastasis. When incubated with migrating monocytes in vitro, MCP1-Gd transport across lymphatic endothelium increased 2-fold relative to nontargeting controls. After administration into mouse models with initial LN metastasis and recurrent LN metastasis, MCP1-Gd detected metastatic LNs by increasing MRI signal by 30-50% relative to healthy LNs. Furthermore, LN targeting was dependent on monocyte hitchhiking, as monocyte depletion decreased accumulation by >70%. Herein, we present a nanoparticle contrast agent for MRI detection of LN metastasis mediated by CCR2-targeting and demonstrate the potential of monocyte hitchhiking for enhanced nanoparticle delivery.

Oral tumor heterogeneity, its implications for patient monitoring and designing anti-cancer strategies

Oral cancer tumors occur in the mouth and are mainly derived from oral mucosa linings. It is one of the most common and fatal malignant diseases worldwide. The intratumor heterogeneity (ITH) of oral cancerous tumor is vast, so it is challenging to study and interpret. Due to environmental selection pressures, ITH arises through diverse genetic, epigenetic, and metabolic alterations. The ITH also talks about peri-tumoral vascular/ lymphatic growth, perineural permeation, tumor necrosis, invasion, and clonal expansion/ the coexistence of multiple subclones in a single tumor. The heterogeneity offers tumors the adaptability to survive, induce growth/ metastasis, and, most importantly, escape antitumor therapy. Unfortunately, the ITH is prioritized less in determining disease pathology than the traditional TNM classifications or tumor grade. Understanding ITH is challenging, but with the advancement of technology, this ITH can be decoded. Tumor genomics, proteomics, metabolomics, and other modern analyses can provide vast information. This information in clinics can assist in understanding a tumor's severity and be used for diagnostic, prognostic, and therapeutic decision-making. Lastly, the oral tumor ITH can lead to individualized, targeted therapy strategies fighting against OC.

The CC ligand chemokine family members CCL17/CCL22 predict the survival and response to immune checkpoint blockade therapy of patients with head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is considered an immunosuppressive malignancy. Cross-talk between cancer cells and immune cells is modulated in part by CC ligand (CCL) chemokines, having a major effect on tumor progression. However, the predictive value and function of CCL family members in HNSCC have not been elucidated. Here, the predictive value of CCL members in cancer prognosis and Immune checkpoint blockade therapy response was investigated. CCL17 and CCL22 were screened as the key CCL chemokines in HNSCC through co-expression analysis. Further, the correlation between CCL17/CCL22 expression and cancer immune infiltration were evaluated based on TIMER and were validated by a set of scRNA-seq data. Moreover, the expression level of CCL17/CCL22 we evaluated to predict the response to Immune checkpoint blockade therapy in a panel of cancer types by using the TIDE database. Results indicated that CCL17/CCL22 had a high co-expression correlation and had a marginally statistical significance with the overall survival in HNSCC patients (P value = 0.057 and 0.055, respectively). Our findings showed high expression of CCL17/CCL22 was positively correlated with CD4⁺ T cell infiltration levels in HNSCCs and activate mTORC1 signaling pathway in CD4⁺ T cells. Further analysis from TIDE showed the high expression of CCL17/CCL22 might predict favorable responses to immune checkpoint blockade therapy in HNSCC patients. These findings provide an insight into the predictive roles of CCL17/CCL22 in HNSCC.

CC Chemokine Ligand-2: A Promising Target for Overcoming Anticancer Drug Resistance

Simple Summary

Drug resistance is an obstacle to cancer therapy, and the underlying mechanisms are still being explored. CC chemokine ligand-2 (CCL2) is one of the key proinflammatory chemokines that regulate the migration and infiltration of multiple inflammatory cells, such as monocytes and macrophages. CCL2 can be secreted by tumor cells and multiple cell types, mediating the formation of the tumor-promoting and immunosuppressive microenvironment to promote cancer development, progression, and anticancer drug resistance. Notably, CCL2 is also frequently overexpressed in drug-resistant cancer cells. Here, we review recent findings regarding the role of CCL2 in the development of resistance to multiple anticancer reagents. In addition, the possible mechanisms by which CCL2 participates in anticancer drug resistance are discussed, which may provide new therapeutic targets for reversing cancer resistance.

Abstract

CC chemokine ligand-2 (CCL2), a proinflammatory chemokine that mediates chemotaxis of multiple immune cells, plays a crucial role in the tumor microenvironment (TME) and promotes tumorigenesis and development. Recently, accumulating evidence has indicated that CCL2 contributes to the development of drug resistance to a broad spectrum of anticancer agents, including chemotherapy, hormone therapy, targeted therapy, and immunotherapy. It has been reported that CCL2 can reduce tumor sensitivity to drugs by inhibiting drug-induced apoptosis, antiangiogenesis, and antitumor immunity. In this review, we mainly focus on elucidating the relationship between CCL2 and resistance as well as the underlying mechanisms. A comprehensive understanding of the role and mechanism of CCL2 in anticancer drug resistance may provide new therapeutic targets for reversing cancer resistance.

Role of the CCL2-CCR2 signalling axis in cancer: Mechanisms and therapeutic targeting

The chemokine ligand CCL2 and its receptor CCR2 are implicated in the initiation and progression of various cancers. CCL2 can activate tumour cell growth and proliferation through a variety of mechanisms. By interacting with CCR2, CCL2 promotes cancer cell migration and recruits immunosuppressive cells to the tumour microenvironment, favouring cancer development. Over the last several decades, a series of studies have been conducted to explore the CCL2-CCR2 signalling axis function in malignancies. Therapeutic strategies targeting the CCL2- CCR2 axis have also shown promising effects, enriching our approaches for fighting against cancer. In this review, we summarize the role of the CCL2-CCR2 signalling axis in tumorigenesis and highlight recent studies on CCL2-CCR2 targeted therapy, focusing on preclinical studies and clinical trials.

The prospects of nanotherapeutic approaches for targeting tumor-associated macrophages in oral cancer

OSCC (oral squamous cell carcinoma) is currently one of the most formidable cancers plagued by challenges like low overall survivability, lymph node associated metastasis, drug resistance, and poor diagnostics. The tumor microenvironment (TME) and its constituent stromal elements are crucial modulators of tumor growth and treatment response, more specifically so with regards to resident tumor associated macrophages (TAMs) and their liaison with the different stromal elements in the tumor niche (Figure 1). Interestingly, there isn't much information on TAM-targeted nanotherapy in OSCC where the first line of therapeutics for oral cancer is surgery with other therapeutics such as chemo- and radiotherapy acting only as adjuvant therapy for oral cancer. In the face of this real time situation, there have been some successful attempts at targeted therapy for OSCC cells and we believe they might elicit favorable responses against TAMs as well. Demanding our immediate attention, this review intends to provide a glimpse of the prevailing anti-TAM treatment strategies, which present great prospect for an uncharted territory like OSCC.

Role of Autophagy in the Microenvironment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma, the most common type of oral cancer, affects more than 275,000 people per year worldwide. Oral squamous cell carcinoma is very aggressive, as most patients die after 3 to 5 years post-diagnosis. The initiation and progression of oral squamous cell carcinoma are multifactorial: smoking, alcohol consumption, and human papilloma virus infection are among the causes that promote its development. Although oral squamous cell carcinoma involves abnormal growth and migration of oral epithelial cells, other cell types such as fibroblasts and immune cells form the carcinoma niche. An underlying inflammatory state within the oral tissue promotes differential stress-related responses that favor oral squamous cell carcinoma. Autophagy is an intracellular degradation process that allows cancer cells to survive under stress conditions. Autophagy degrades cellular components by sequestering them in vesicles called autophagosomes, which ultimately fuse with lysosomes. Although several autophagy markers have been associated with oral squamous cell carcinoma, it remains unclear whether up- or down-regulation of autophagy favors its progression. Autophagy levels during oral squamous cell carcinoma are both timing- and cell-specific. Here we discuss how autophagy is required to establish a new cellular microenvironment in oral squamous cell carcinoma and how autophagy drives the phenotypic change of oral squamous cell carcinoma cells by promoting crosstalk between carcinoma cells, fibroblasts, and immune cells.

Epithelial-to-mesenchymal transition in oral squamous cell carcinoma: Challenges and opportunities

Oral squamous cell carcinoma (OSCC) is the most common malignancy representing 90% of all forms of oral cancer worldwide. Although great efforts have been made in the past decades, the 5-year survival rate of OSCC patients is no more than 60% due to tumor metastasis and subsequent recurrence. The metastasis from the primary site is due to a complex process known as epithelial-to-mesenchymal transition (EMT). During the EMT, epithelial cells gradually acquire the structural and functional characteristics of mesenchymal cells, leading to the upregulation of cell migration and the promotion of tumor cell dissemination. Therefore, EMT attracted broad attention due to its close relationship with cancer invasion and metastasis. Therefore, in the present review, an extensive description of the current research on OSCC and the role of EMT in this cancer type is provided, including diverse EMT markers, regulatory networks and crucial EMT-inducing transcription factors in OSCC. Moreover, a brief summary was made regarding the current application of EMT-correlated indexes in the prognostic analysis of OSCC patients, and the potential therapeutic approaches against OSCC and difficulties in the development of an effective anti-EMT treatment are discussed. Our aim is to provide novel insights to develop new strategies to combat OSCC by targeting EMT.

Macrophage‑derived exosomes attenuate the susceptibility of oral squamous cell carcinoma cells to chemotherapeutic drugs through the AKT/GSK‑3β pathway

Although chemotherapy is initially effective in debulking tumor mass in a number of different types of malignancy, tumor cells gradually acquire chemoresistance and frequently progress to advanced clinical stage. Accumulating evidence has indicated that the tumor sensitivity to several chemotherapeutic drugs is regulated by tumor stromal cells including macrophages. However, the role of macrophages in the efficacy of chemotherapeutics on oral squamous cell carcinoma (OSCC) cells is poorly understood. In the present study, the effects of macrophage-secreted exosomes on the sensitivity of OSCC cells towards chemotherapeutic agents were examined. Specifically, the effects of exosomes derived from THP-1 cells and primary human macrophages (PHM) were assessed on the chemosensitivity of OSC-4 cells treated with 5-fluorouracil (5-FU) and cis-diamminedichloroplatinum (CDDP). The THP-1- and PHM-derived exosomes promoted dose-dependent proliferation, decreased the proliferative inhibitory effects of 5-FU and CDDP and decreased apoptosis in OSC-4 cells through activation of the AKT/glycogen synthase kinase-3β signaling pathway. LY294002, a PI3K inhibitor, and MK-2206, an AKT inhibitor, were both able to suppress the observed decrease in sensitivity to chemotherapeutic agents induced by exosomes. Overall, the data from the present study suggested that the macrophage-derived exosomes may decrease the sensitivity to chemotherapeutic agents in OSCC cells. Thus, targeting the interaction between OSCC cells and macrophage-derived exosomes may be considered as a therapeutic approach to improve the chemosensitivity of the tumor microenvironment in oral cancer.

Expressions of extracellular matrix-remodeling factors in lymph nodes from oral cancer patients

OBJECTIVE

Most malignant tumors require remodeling extracellular matrices (ECMs) for invasive growth and metastasis. Cancer cells and stromal cells remodel ECM. We investigated the relationship between regional lymph node (LN) metastasis and expression of ECM-remodeling factors in oral squamous cell carcinoma (OSCC).

METHODS

Using primary OSCC and cervical LNs obtained surgically, we performed immunohistochemical evaluation of the ECM-remodeling factors, lysyl oxidase (LOX), MT1-MMP, S100A8, and TIMP-1 in primary tumor and marginal sinus histiocytosis (MSH) in LNs, and determined the statistical significance of the positive rates between metastatic and metastasis-free groups.

RESULTS

Marginal sinus histiocytosis was more frequently formed in the metastatic group compared to the metastasis-free group. Lymphatic metastasis correlated with the immunopositivity rates of tumor cells expressing LOX, MT1-MMP, and TIMP-1, and of stromal cells expressing TIMP-1. The case rates of MSH containing macrophages positive for LOX and MT1-MMP in the metastasis group were significantly higher than in the metastasis-free group. ECM-remodeling-associated macrophages accumulate in marginal sinus in conjunction with lymphatic metastasis.

CONCLUSION

Expression of LOX, MT1-MMP, and TIMP-1 in the parenchyma, and stromal expression of TIMP-1 in primary tumor may predict lymphatic metastasis. LOX and MT1-MMP have a possibility to participate in formation of pre-metastatic niche in LNs.

Over-expression of Nav1.6 channels is associated with lymph node metastases in colorectal cancer

Background and objectives

Lymph node metastasis is a key factor in predicting and determining the prognosis of patients with colorectal cancer (CRC). Sodium channels are highly expressed in a variety of tumors and are closely related to tumor development, metastasis, and invasion. We investigated the relationship between the expressions of different subtypes of Nav channels and lymph node metastasis of CRC.

Methods

Real-time PCR (RT-qPCR) was carried out to measure the expressions of different sodium channel subtypes, chemokine receptors (CCR2, CCR4, CCR7), and lymphocyte infiltration-related biomarkers (CD3e, CD8a, IL-2RA) in CRC tissues from 97 patients. The expressions of Nav1.5 and Nav1.6 in surgically isolated lymph nodes were detected by immunohistochemistry. Correlation analysis between expressions of different genes and lymph node metastasis was performed by two-tailed t test.

Results

Nav1.1 and Nav1.6 were highly expressed in CRC tissues and positively correlated with CRC lymph node metastasis. Nav1.6 was also highly expressed in metastatic lymph nodes. Further analysis showed that the high expression of Nav1.6 was closely related to the one of CCR2\CCR4 in tumor lymph node metastasis.

Conclusions

These results suggested that Nav1.6 might be a novel marker for CRC lymph node metastasis.

CCL2 promotes cell migration by inducing epithelial-mesenchymal transition in oral squamous cell carcinoma

BACKGROUND

Although a few studies suggested that the chemokine CCL2 might be involved in the development of oral squamous cell carcinoma (OSCC), the exact mechanism remains unclear. In this study, we aimed to determine the resource of CCL2 in lesions and explored a potential mechanism that CCL2 promotes tumor progression. The study was an effort to provide new insights into the pathological role of CCL2 in OSCC.

METHODS

Specimens of OSCC and normal oral mucosa were stained using immunohistochemistry (IHC) to assess the CCL2 expression. Enzyme-linked immunosorbent assay (ELISA) was used to detect the difference of CCL2 between OSCC and normal oral mucosa cell lines. In addition, we treated OSCC cells with exogenous rCCL2 combined with or without CCL2 neutralizing antibody and then determined the changes of in epithelial-mesenchymal transition (EMT) markers and cell migration capacity using immunofluorescence, Western blotting, transwell migration, and wound healing assays.

RESULTS

We have found that CCL2 expression was upregulated significantly in both lesions and cell culture supernatant of OSCC compared with controls. IHC staining demonstrated that CCL2 expression was primarily located in the cytoplasm and cell membrane of cells. We have also found that rCCL2 could effectively induce EMT through upregulating Snail in OSCC cells, which was demonstrated by the decrease of E-cadherin and the increase of vimentin. In addition, we have found that CCL2 neutralizing antibody could block EMT induced by CCL2 in OSCC.

CONCLUSIONS

CCL2 secreted by cancer cells can promote cell migration by inducing EMT via paracrine or autocrine in OSCC.