Search

Colorectal cancer (CRC) is a leading cause of cancer mortality worldwide, and cancer-associated fibroblasts (CAFs) play a major role in the tumor microenvironment (TME), which facilitates the progression of CRC. It is critical to understand how CAFs promote the progression of CRC for the development of novel therapeutic approaches. The purpose of this study was to understand how CAF-derived stromal-derived factor-1 (SDF-1) and its interactions with the corresponding C-X-C motif chemokine receptor 4 (CXCR4) promote CRC progression. Our study focused on their roles in promoting tumor cell migration and invasion and their effects on the characteristics of cancer stem cells (CSCs), which ultimately impact patient outcomes. Here, using in vivo approaches and clinical histological samples, we analyzed the influence of secreted SDF-1 on CRC progression, especially in terms of tumor cell behavior and stemness. We demonstrated that CAF-secreted SDF-1 significantly enhanced CRC cell migration and invasion through paracrine signaling. In addition, the overexpression of SDF-1 in CRC cell lines HT29 and HCT-116 triggered these cells to generate autocrine SDF-1 signaling, which further enhanced their CSC characteristics, including those of migration, invasion, and spheroid formation. An immunohistochemical study showed a close relationship between SDF-1 and CXCR4 expression in CRC tissue, and this significantly affected patient outcomes. The administration of AMD3100, an inhibitor of CXCR4, reversed the entire phenomenon. Our results strongly suggest that targeting this signaling axis in CRC is a feasible approach to attenuating tumor progression, and it may, therefore, serve as an alternative treatment method to improve the prognosis of patients with CRC, especially those with advanced, recurrent, or metastatic CRC following standard therapy. [ABSTRACT FROM AUTHOR]

Pulmonary adenocarcinoma (PADC) treatment limited efficacy in preventing tumor progression, often resulting in malignant pleural effusion (MPE). MPE is filled with various mediators, especially interleukin-8 (IL-8). However, the role of IL-8 and its signaling mechanism within the fluid microenvironment (FME) implicated in tumor progression warrants further investigation. Primary cultured cells from samples of patients with MPE from PADC, along with a commonly utilized lung cancer cell line, were employed to examine the role of IL-8 and its receptor, CXCR1, through comparative analysis. Our study primarily assessed migration and invasion capabilities, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) properties. Additionally, IL-8 levels in MPE fluid versus serum, along with immunohistochemical expression of IL-8/CXCR1 signaling in tumor tissue and cell blocks were analyzed. IL-8/CXCR1 overexpression enhanced EMT and CSC properties. Furthermore, the immunocytochemical examination of 17 cell blocks from patients with PADC and MPE corroborated the significant correlation between upregulated IL-8 and CXCR1 expression and the co-expression of IL-8 and CXCR1 in MPE with distant metastasis. In summary, the IL-8/ CXCR1 axis in FME is pivotal to tumor promotion via paracrine and autocrine signaling. Our study provides a therapeutic avenue for improving the prognosis of PADC patients with MPE. [ABSTRACT FROM AUTHOR]

Long-term nicotine-derived nitrosamine ketone (NNK) and arecoline exposure promotes carcinogenesis and head and neck squamous cell carcinoma (HNSCC) progression, although most associated data on the two were analyzed individually. The molecular mechanisms underlying tumor progression associated with the synergistic effects of NNK and arecoline remain unclear. We treated SCC-25 and FaDu cells with NNK and arecoline (separately or in combination) for 3 months. Comparative analysis was performed to investigate the mechanism underlying the acquisition of properties related to tumor promotion, including stemness, anti-apoptosis, and resistance to HNSCC therapeutics. Long-term exposure to NNK and arecoline resulted in an increase in cancer stem cell properties, anti-apoptosis, and the resistance to cisplatin in HNSCC. We detected abundant epidermal growth factor receptor (EGFR) expression in HNSCC cells after combined treatment with NNK and arecoline. EGFR was pivotal in inducing tumor promotion and anti-apoptosis in cancer cells by inducing pAKT and NFκB. Combined treatment with NNK and arecoline synergistically facilitated tumor aggressiveness via EGFR–AKT signaling. Targeting EGFR–AKT signaling may be a feasible strategy for treating HNSCC. [ABSTRACT FROM AUTHOR]

Background. Recent studies suggest that long-term exposure of the carcinogen 4-methylnitrosamino-1--3-pyridyl-1-butanone (NNK) found in tobacco smoke is involved in the progression of head and neck squamous cell carcinoma (HNSCC). The underlying nicotine-mediated mechanism remains unclear. Methods. An analysis of SCC-25 and Fadu cells with or without NNK exposure focusing on the evaluation of migration and invasion abilities, the expression of epithelial--mesenchymal transition, drug-resistance-related genes, properties of cancer stem cells (CSCs), and anti-apoptosis was performed. Results. Long-term NNK exposure enhances migration and invasion with morphological alterations in a dose-dependently manner. Furthermore, NNK exposure also upregulates Snail, promotes sphere-forming ability, Background. Recent studies suggest that long-term exposure of the carcinogen 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) found in tobacco smoke is involved in the progression of head and neck squamous cell carcinoma (HNSCC). The underlying nicotine-mediated mechanism remains unclear. Methods. An analysis of SCC-25 and Fadu cells with or without NNK exposure focusing on the evaluation of migration and invasion abilities, the expression of epithelial--mesenchymal transition, drug-resistance-related genes, properties of cancer stem cells (CSCs), and anti-apoptosis was performed. Results. Long-term NNK exposure enhances migration and invasion with morphological alterations in a dose-dependently manner. Furthermore, NNK exposure also upregulates Snail, promotes sphere-forming ability, and overexpresses aldehyde dehydrogenase 1 (ALDH1), Nanog, OCT4, ABCG2, and MDR1. Conclusion. The current study confirmed that long-term NNK exposure plays a role in HNSCC by increasing anti-apoptosis and therapeutic resistance via the Snail-RKIP signaling pathway. Our data also suggest that a7 nicotinic acetylcholine receptor (α7-nAChR) inhibition or targeting Snail may provide a feasible rationale for preventing the progression of HNSCC. [ABSTRACT FROM AUTHOR]

Background: Metastasis occurs in a series of discrete steps involving invasion, angiogenesis, lymphovascular space permeation, and establishment of secondary tumors. Malignant pleural effusion (MPE), a type of tumor metastasis, is usually a poor prognostic sign for patients with pulmonary adenocarcinoma, although its underlying mechanism has received less attention than other types of metastases have. The objective of the current study was to confirm whether cancer stem cells (CSCs) in MPE contribute to the “metastatic cascade” through the epithelial – mesenchymal transition (EMT), anoikis, and adaptation in the microenvironment. Methods: Pulmonary tissue and corresponding cell blocks of MPE samples from 20 patients with primary adenocarcinoma were analyzed by immunohistochemical staining with CSC-representative markers (CD133, Nanog, and OCT-4) and EMT-associated markers (E-cadherin and vimentin). Correlations between these variables and clinico-pathological parameters were analyzed. Primary cultures from eight cases of MPE were investigated to characterize the CSC properties, including marker expression, sphere formation, and differentiation. Results: Expressions of CSC-representative markers for 20 cases of MPE cell blocks were quite diverse and variable ranging from 15% to 90%. Stronger expression of CSC-representative markers and alteration of EMT-associated markers were found at the invasive fronts and in MPEs compared with the expression in primary pulmonary tumor tissues. The expression of OCT-4 in MPEs significantly related to distant metastasis and stage, as well as inversely correlated with patient survival. Primary cultures confirmed the CSC properties in MPE. Five of eight cases of MPE yielded adequate cell clusters, which also showed variable expressions of CSC markers in addition to sphere formation and the ability for differentiation and metastasis. Conclusion: This pilot study offers a better understanding of the metastatic cascade. Establishing a model of MPE will provide further insight into the role of CSCs in metastasis and may explain the high therapeutic failure rates for patients with MPE. [ABSTRACT FROM AUTHOR]