Blockage of Squamous Cancer Cell Collective Invasion by FAK Inhibition Is Released by CAFs and MMP-2

Matrix Metalloproteinases and Their Inhibitors as Potential Prognostic Biomarkers in Head and Neck Cancer after Radiotherapy

Head and neck cancer (HNC) is among the ten most frequent tumours, with 5-year survival rates varying from 30% to 70% depending on the stage and location of the tumour. HNC is traditionally known as head and neck squamous cell carcinoma (HNSCC), since 90% arises from epithelial cells. Metastasis remains a major cause of mortality in patients with HNSCC. HNSCC patients with metastatic disease have an extremely poor prognosis with a survival rate of less than a year. Matrix metalloproteinases (MMPs) have been described as biomarkers that promote cell migration and invasion. Radiotherapy is widely used to treat HNSCC, being a determining factor in the alteration of the tumour's biology and microenvironment. This review focuses on analysing the current state of the scientific literature on this topic. Although few studies have focused on the role of these proteinases in HNC, some authors have concluded that radiotherapy alters the behaviour of MMPs and tissue inhibitors of metalloproteinases (TIMPs). Therefore, more research is needed to understand the roles played by MMPs and their inhibitors (TIMPs) as prognostic biomarkers in patients with HNC and their involvement in the response to radiotherapy.

Focal-adhesion kinase regulates the sialylation of N-glycans via the PI4KIIα-PI4P pathway

Sialylation is a terminal glycosylated modification of glycoproteins that regulates critical biological events such as cell adhesion and immune response. Our previous study showed that integrin α3β1 plays a crucial role in regulating the sialylation of N-glycans. However, the underlying mechanism for the regulation remains unclear. This study investigated how sialylation is affected by focal adhesion kinase (FAK), which is a critical downstream signal molecule of integrin β1. We established a stable FAK knockout (KO) cell line using the CRISPR/Cas9 system in HeLa cells. The results obtained from lectin blot, flow cytometric analysis, and MS showed that the sialylation levels were significantly decreased in the KO cells compared with that in wild-type (WT) cells. Moreover, phosphatidylinositol 4-phosphate (PI4P) expression levels were also reduced in the KO cells due to a decrease in the stability of phosphatidylinositol 4-kinase-IIα (PI4KIIα). Notably, the decreased levels of sialylation, PI4P, and the complex formation between GOLPH3 and ST3GAL4 or ST6GAL1, which are the main sialyltransferases for modification of N-glycans, were significantly restored by the re-expression of FAK. Furthermore, the decreased sialylation and phosphorylation of Akt and cell migration caused by FAK deficiency all were restored by overexpressing PI4KIIα, which suggests that PI4KIIα is one of the downstream molecules of FAK. These findings indicate that FAK regulates sialylation via the PI4P synthesis pathway and a novel mechanism is suggested for the integrin-FAK-PI4KIIα-GOLPH3-ST axis modulation of sialylation in N-glycans.

Mechanical factors driving cancer progression

A fundamental step of tumor metastasis is tumor cell migration away from the primary tumor site. One mode of migration that is essential but still understudied is collective invasion, the process by which clusters of cells move in a coordinated fashion. In recent years, there has been growing interest to understand factors regulating collective invasion, with increasing number of studies investigating the biomechanical regulation of collective invasion. In this review we discuss the dynamic relationship between tumor microenvironment cues and cell response by first covering mechanical factors in the microenvironment and second, discussing the mechanosensing pathways utilized by cells in collective clusters to dynamically respond to mechanical matrix cues. Finally, we discuss model systems that have been developed which have increased our understanding of the mechanical factors contributing to tumor progression.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Pirfenidone Reduces Epithelial-Mesenchymal Transition and Spheroid Formation in Breast Carcinoma through Targeting Cancer-Associated Fibroblasts (CAFs)

The aim of this study was to assess the effects of pirfenidone (PFD) on promoting epithelial-mesenchymal-transition (EMT) and stemness features in breast carcinoma cells through targeting cancer-associated-fibroblasts (CAFs). Using The Cancer Genome Atlas (TCGA) database, we analyzed the association between stromal index, EMT, and stemness-related genes across 1084 breast cancer patients, identifying positive correlation between YAP1, EMT, and stemness genes in samples with a high-stromal index. We monitored carcinoma cell invasion and spheroid formation co-cultured with CAFs in a 3D microfluidic device, followed by exposing carcinoma cells, spheroids, and CAFs with PFD. We depicted a positive association between the high-stromal index and the expression of EMT and stemness genes. High YAP1 expression in samples correlated with more advanced EMT status and stromal index. Additionally, we found that CAFs promoted spheroid formation and induced the expression of YAP1, VIM, and CD44 in spheroids. Treatment with PFD reduced carcinoma cell migration and decreased the expression of these genes at the protein level. The cytokine profiling showed significant depletion of various EMT- and stemness-regulated cytokines, particularly IL8, CCL17, and TNF-beta. These data highlight the potential application of PFD on inhibiting EMT and stemness in carcinoma cells through the targeting of critical cytokines.