Increase in CD4+FOXP3+ regulatory T cell number and upregulation of the HGF/c-Met signaling pathway during the liver metastasis of colorectal cancer

Understanding pre-metastatic niche formation: implications for colorectal cancer liver metastasis

The liver is the most commonly metastasized organ in colorectal cancer (CRC), and distant metastasis is the primary cause of mortality from CRC. In recent years, researchers have discovered that tumor cells create a "pre-metastatic niche (PMN)" favorable to metastasis before reaching the metastatic location. This review discusses the many processes and mechanisms that lead to PMN formation in CRC, including gut microbiota, stem cell stimulation, immunocyte interactions, and the induction of extracellular vesicles that carry important information. It examines research methods and diagnostic and therapeutic approaches for treating metastatic CRC with PMN. The crucial significance of PMN formation in metastatic CRC is also highlighted.

c-MET and the immunological landscape of cancer: novel therapeutic strategies for enhanced anti-tumor immunity

Cellular mesenchymal-epithelial transition factor (c-MET), also known as hepatocyte growth factor receptor (HGFR), is a crucial receptor tyrosine kinase implicated in various solid tumors, including lung, breast, and liver cancers. The concomitant expression of c-MET and PD-L1 in tumors, such as hepatocellular carcinoma, highlights their prognostic significance and connection to therapeutic resistance. Cancer-associated fibroblasts and mesenchymal stromal cells produce hepatocyte growth factor (HGF), activating c-MET signaling in tumor cells and myeloid-derived suppressor cells (MDSC). This activation leads to metabolic reprogramming and increased activity of enzymes like glutaminase (GLS), indoleamine 2,3-dioxygenase (IDO), and arginase 1 (ARG1), depleting essential amino acids in the tumor microenvironment that are vital for effector immune cell function. This review highlights the interplay between tumor cells and myeloid-derived suppressor cells (MDSCs) that create an immunosuppressive environment while providing targets for c-MET-focused immunotherapy. It emphasizes the clinical implications of c-MET inhibition on the behavior of immune cells such as neutrophils, macrophages, T cells, and NK cells. It explores the potential of c-MET antagonism combined with immunotherapeutic strategies to enhance cancer treatment paradigms. This review also discusses the innovative cancer immunotherapies targeting c-MET, including chimeric antigen receptor (CAR) therapies, monoclonal antibodies, and antibody-drug conjugates, while encouraging the development of a comprehensive strategy that simultaneously tackles immune evasion and enhances anti-tumor efficacy further to improve the clinical prognoses for patients with c-MET-positive malignancies. Despite the challenges and variability in efficacy across different cancer subtypes, continued research into the molecular mechanisms and the development of innovative therapeutic strategies will be crucial.

Impact of immunotherapy on liver metastasis

This editorial discusses the article "Analysis of the impact of immunotherapy efficacy and safety in patients with gastric cancer and liver metastasis" published in the latest edition of the World Journal of Gastrointestinal Surgery. Immunotherapy has achieved outstanding success in tumor treatment. However, the presence of liver metastasis (LM) restrains the efficacy of immunotherapy in various tumors, including lung cancer, colorectal cancer, renal cell carcinoma, melanoma, and gastric cancer. A decrease in CD8+ T cells and nature killer cells, along with an increase in macrophages and regulatory T cells, was observed in the microenvironment of LM, leading to immunotherapy resistance. More studies are necessary to determine the best strategy for enhancing the effectiveness of immunotherapy in patients with LM.

Joint DNA-RNA-based NGS for diagnosis and treatment of a rare CD47-MET fusion lung adenocarcinoma which was immunoresistant and savoltinib-sensitive: a case report

Targeted therapy and immunotherapy are both important in the treatment of non-small-cell lung cancer (NSCLC). Accurate diagnose and precise treatment are key in achieving long survival of patients. MET fusion is a rare oncogenic factor, whose optimal detection and treatment are not well established. Here, we report on a 32-year-old female lung adenocarcinoma patient with positive PD-L1 and negative driver gene detected by DNA-based next-generation sequencing (NGS). A radical resection of the primary lesion after chemotherapy combined with PD-1 checkpoint inhibitor administration indicated primary immuno-resistance according to her pathological response and rapid relapse. A rare CD47-MET was detected by RNA-based NGS, which was confirmed by fluorescence in situ hybridization. Multiplex immunofluorescence revealed a PD-L1 related heterogeneous immunosuppressive microenvironment with little distribution of CD4+ T cells and CD8+ T cells. Savolitinib therapy resulted in a progression-free survival (PFS) of >12 months, until a new secondary resistance mutation in MET p.D1228H was detected by re-biopsy and joint DNA-RNA-based NGS after disease progression. In this case, CD47-MET fusion NSCLC was primarily resistant to immunotherapy, sensitive to savolitinib, and developed secondary MET p.D1228H mutation after targeted treatment. DNA-RNA-based NGS is useful in the detection of such molecular events and tracking of secondary mutations in drug resistance. To this end, DNA-RNA-based NGS may be of better value in guiding precise diagnosis and individualized treatment in this patient population.

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

Spatial Transcriptomic Profiling of Tetraspanins in Stage 4 Colon Cancer from Primary Tumor and Liver Metastasis

Stage 4 colon cancer (CC) presents a significant global health challenge due to its poor prognosis and limited treatment options. Tetraspanins, the transmembrane proteins involved in crucial cancer processes, have recently gained attention as diagnostic markers and therapeutic targets. However, their spatial expression and potential roles in stage 4 CC tissues remain unknown. Using the GeoMx digital spatial profiler, we profiled all 33 human tetraspanin genes in 48 areas within stage 4 CC tissues, segmented into immune, fibroblast, and tumor compartments. Our results unveiled diverse gene expression patterns across different primary tumor sub-regions. CD53 exhibited distinct overexpression in the immune compartment, hinting at a potential role in immune modulation. TSPAN9 was specifically overexpressed in the fibroblast compartment, suggesting involvement in tumor invasion and metastasis. CD9, CD151, TSPAN1, TSPAN3, TSPAN8, and TSPAN13 displayed specific overexpression in the tumor compartment, indicating potential roles in tumor growth. Furthermore, our differential analysis revealed significant spatial changes in tetraspanin expression between patient-matched stage 4 primary CC and metastatic liver tissues. These findings provide spatially resolved insights into the expression and potential roles of tetraspanins in stage 4 CC progression, proposing their utility as diagnostic markers and therapeutic targets. Understanding this landscape is beneficial for tailoring therapeutic strategies to specific sub-tumor regions in the context of stage 4 CC and liver metastasis.

Multilevel Heterogeneity of Colorectal Cancer Liver Metastasis

Colorectal cancer liver metastasis (CRLM) is a highly heterogeneous disease. Therapies that target both primary foci and liver metastasis are severely lacking. Therefore, understanding the features of metastatic tumor cells in the liver is valuable for the overall control of CRLM patients. In this review, we summarize the heterogeneity exhibited in CRLM from five aspects (gene, transcriptome, protein, metabolism, and immunity). In addition to genetic heterogeneity, the other four aspects exhibit significant heterogeneity. Compared to primary CRC, the dysregulation of epithelial-mesenchymal transition (EMT)-related proteins, the enhanced metabolic activity, and the increased infiltration of immunosuppressive cells are detected in CRLM. Preclinical evidence shows that targeting the EMT process or enhancing cellular metabolism may represent a novel approach to increasing the therapeutic efficacy of CRLM.

ERK Signaling Pathway Is Constitutively Active in NT2D1 Non-Seminoma Cells and Its Inhibition Impairs Basal and HGF-Activated Cell Proliferation

c-MET/hepatocyte growth factor (HGF) system deregulation is a well-known feature of malignancy in several solid tumors, and for this reason this system and its pathway have been considered as potential targets for therapeutic purposes. In previous manuscripts we reported c-MET/HGF expression and the role in testicular germ cell tumors (TGCTs) derived cell lines. We demonstrated the key role of c-Src and phosphatidylinositol 3-kinase (PI3K)/AKT adaptors in the HGF-dependent malignant behavior of the embryonal carcinoma cell line NT2D1, finding that the inhibition of these onco-adaptor proteins abrogates HGF triggered responses such as proliferation, migration, and invasion. Expanding on these previous studies, herein we investigated the role of mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase (ERK) pathways in the HGF-dependent and HGF-independent NT2D1 cells biological responses. To inhibit MAPK/ERK pathways we chose a pharmacological approach, by using U0126 inhibitor, and we analyzed cell proliferation, collective migration, and chemotaxis. The administration of U0126 together with HGF reverts the HGF-dependent activation of cell proliferation but, surprisingly, does not exert the same effect on NT2D1 cell migration. In addition, we found that the use of U0126 alone significantly promotes the acquisition of NT2D1 «migrating phenotype», while collective migration of NT2D1 cells was stimulated. Notably, the inhibition of ERK activation in the absence of HGF stimulation resulted in the activation of the AKT-mediated pathway, and this let us speculate that the paradoxical effects obtained by using U0126, which are the increase of collective migration and the acquisition of partial epithelium-mesenchyme transition (pEMT), are the result of compensatory pathways activation. These data highlight how the specific response to pathway inhibitors, should be investigated in depth before setting up therapy.

The tumor-immune ecosystem in shaping metastasis

A better understanding of the mechanisms regulating cancer metastasis is critical to develop new therapies and decrease mortality. Emerging evidence suggests that the interactions between tumor cells and the host immune system play important roles in establishing metastasis. Tumor cells are able to recruit immune cells, which in turn promotes tumor cell invasion, intravasation, survival in circulation, extravasation, and colonization in different organs. The tumor-host immunological interactions also generate a premetastatic niche in distant organs which facilitates metastasis. In this review, we summarize the recent findings on how tumor cells and immune cells regulate each other to coevolve and promote the formation of metastases at the major organ sites of metastasis.

Early mortality factors in immune checkpoint inhibitor monotherapy for advanced or metastatic non-small cell lung cancer

Purpose

Immune checkpoint inhibitors (ICI) are a promising treatment, but may cause hyperprogressive disease and early death. The present study investigated early mortality factors in ICI monotherapy for lung cancer.

Patients and methods

We retrospectively reviewed all patients diagnosed with advanced or metastatic non-small cell lung cancer (NSCLC) and treated with ICI monotherapy (nivolumab, pembrolizumab, and atezolizumab) between March 2016 and August 2021 at National Hospital Organization Kochi Hospital and Tokushima University. Early death was defined as patients who died within 60 days of ICI treatment.

Results

A total of 166 patients were included. The majority of patients (87%) had an Eastern cooperative oncology group (ECOG) Performance status (PS) of 0/1. There were 21 early deaths. Significant differences were observed in ECOG PS, the histological type, liver metastasis, tumor size, the white blood cell count, neutrophils (%), lymphocytes (%), the neutrophil-to-lymphocyte ratio in serum (sNLR), C-reactive protein (CRP), and albumin between the groups with or without early death. Univariate logistic regression analyses identified ECOG PS score ≥ 2, liver metastasis, tumor size ≥ 5 cm, neutrophils ≥ 69%, lymphocytes < 22%, sNLR ≥ 4, CRP ≥ 1 mg/dl, and albumin < 3.58 g/dl as significant risk factors for early death. A multivariate logistic regression analysis revealed that liver metastasis (Odds ratio [OR], 10.3; p = 0.008), ECOG PS score ≥ 2 (OR, 8.0; p = 0.007), and a smoking history (OR, 0.1; p = 0.03) were significant risk factors for early death.

Conclusion

Liver metastases, ECOG PS score ≥ 2, and a non-smoking history are early mortality factors in ICI monotherapy for advanced or metastatic NSCLC.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Multilevel mechanism of immune checkpoint inhibitor action in solid tumors: History, present issues and future development (Review)

Immunotherapy with checkpoint inhibitors (antibodies that target and block immune checkpoints in the tumor microenvironment) is included in the standard of care for patients with different types of malignancy, such as melanoma, renal cell and urothelial carcinoma, lung cancer etc. The introduction of this new immunotherapy has altered the view on potential targets for treatment of solid tumors from tumor cells themselves to their immune microenvironment; this has led to a reconsideration of the mechanisms of tumor-associated immunity. However, only a subset of patients benefit from immunotherapy and patient response is often unpredictable, even with known initial levels of prognostic markers; the biomarkers for favorable response are still being investigated. Mechanisms of immune checkpoint inhibitors efficiency, as well as the origins of treatment failure, require further investigation. From a clinical standpoint, discrepancies between the theoretical explanation of inhibitors of immune checkpoint actions at the cellular level and their deployment at a tissue/organ level impede the effective clinical implementation of novel immune therapy. The present review assessed existing experimental and clinical data on functional activity of inhibitors of immune checkpoints to provide a more comprehensive picture of their mechanisms of action on a cellular and higher levels of biological organization.

Emerging mechanisms progress of colorectal cancer liver metastasis

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastasis. The hepatic portal venous system, responsible for collecting most intestinal blood, makes the liver the most common site of CRC metastasis. The formation of liver metastases from colorectal cancer is a long and complex process. It involves the maintenance of primary tumors, vasculature invasion, distant colonization, and metastasis formation. In this review, we serve on how the CRC cells acquire stemness, invade the vascular, and colonize the liver. In addition, we highlight how the resident cells of the liver and immune cells interact with CRC cells. We also discuss the current immunotherapy approaches and challenges we face, and finally, we look forward to finding new therapeutic targets based on novel sequencing technologies.

CXCR4 promotes gefitinib resistance of Huh7 cells by activating the c-Met signaling pathway

C-X-C chemokine receptor type 4 (CXCR4) expression is associated with poor prognosis of hepatocellular carcinoma (HCC). The aim of this study was to explore the biological role of CXCR4 in gefitinib resistance of HCC. Compared with a normal, non-gefitinib-resistant, human HCC cell line (Huh7), CXCR4 mRNA and protein were highly expressed in gefitinib-resistant Huh7 cells (Huh7-R). Cell proliferation was decreased, and apoptosis was enhanced in Huh7 cells in the presence of gefitinib. These influences conferred by gefitinib treatment on proliferation and apoptosis of Huh7 cells were abolished by CXCR4 overexpression. CXCR4 knockdown reduced the proliferation ability of HuH-7R cells after gefitinib treatment. Importantly, CXCR4 overexpression had no influence on caveolin 1 (Cav-1) expression; similarly, Cav-1 silencing did not cause a substantive change in CXCR4 expression. However, CXCR4 activated Cav-1, c-Met, and Raf-1 in Huh7 cells, whereas Cav-1 silencing repressed the expression of Raf-1 and phosphorylated c-Met in Huh7 cells. CXCR4 overexpression promoted proliferation and repressed apoptosis in gefitinib-treated Huh7 cells, which was partly rescued by PHA-665752 (a c-Met inhibitor) treatment or c-Met deficiency. Finally, we constructed a tumor xenograft model to determine the influence of CXCR4 overexpression on tumor growth of HCC. CXCR4 overexpression accelerated tumor growth of HCC, which was abrogated by c-Met deficiency. These findings demonstrate that CXCR4 overexpression activates c-Met via the Cav-1 signaling pathway, thereby promoting gefitinib resistance of Huh7 cells. Thus, this study highlights novel insights into the mechanism of gefitinib resistance of HCC and CXCR4 may become a potential target for HCC treatment.