Cancer-associated Fibroblast-derived Spondin-2 Promotes Motility of Gastric Cancer Cells

Biophysical perspectives to understanding cancer-associated fibroblasts

The understanding of cancer has evolved significantly, with the tumor microenvironment (TME) now recognized as a critical factor influencing the onset and progression of the disease. This broader perspective challenges the traditional view that cancer is primarily caused by mutations, instead emphasizing the dynamic interaction between different cell types and physicochemical factors within the TME. Among these factors, cancer-associated fibroblasts (CAFs) command attention for their profound influence on tumor behavior and patient prognoses. Despite their recognized importance, the biophysical and mechanical interactions of CAFs within the TME remain elusive. This review examines the distinctive physical characteristics of CAFs, their morphological attributes, and mechanical interactions within the TME. We discuss the impact of mechanotransduction on CAF function and highlight how these cells communicate mechanically with neighboring cancer cells, thereby shaping the path of tumor development and progression. By concentrating on the biomechanical regulation of CAFs, this review aims to deepen our understanding of their role in the TME and to illuminate new biomechanical-based therapeutic strategies.

The Important Role of GPX1 and NF-κB Signaling Pathway in Human Gastric Cancer: Implications for Cell Proliferation and Invasion

BACKGROUND/AIM

Glutathione peroxidases (GPXs) are crucial antioxidant enzymes, counteracting reactive oxygen species (ROS). GPX overexpression promotes proliferation and invasion in cancer cells. Glutathione peroxidase-1 (GPX1), the most abundant isoform, contributes to invasion, migration, cisplatin resistance, and proliferation in various cancers. Nuclear factor-kappa B (NF-[Formula: see text]B) participates in cell proliferation, apoptosis, and tumor progression. The inhibition of NF-[Formula: see text]B expression reduces the malignancy of esophageal squamous cell carcinoma. This study aimed to explore the GPX1 and NF-[Formula: see text]B signaling pathways and their correlation with gastric cancer cell proliferation and invasion.

MATERIALS AND METHODS

Cell culture, complementary DNA microarray analysis, western blotting, reverse transcription-polymerase chain reaction, zymography, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, GPX1 knock-down with short hairpin RNA (shRNA), standard two-chamber invasion assay, chromatin immunoprecipitation assay.

RESULTS

Hepatocyte growth factor (HGF) up-regulated GPX1 expression in gastric cancer cells. The NF-[Formula: see text]B inhibitor, pyrrolidine dithiocarbamate down-regulated HGF-induced GPX1 protein levels. Furthermore, NF-[Formula: see text]B and urokinase-type plasminogen activators were down-regulated in GPX1-shRNA-treated cells. Treatment with an Akt pathway inhibitor (LY294002) led to the down-regulation of GPX1 and NF-[Formula: see text]B gastric cancer cells. GPX1 knockdown resulted in decreased HGF-mediated in vitro cell proliferation and invasion. The study identified the putative binding site of the GPX1 promoter containing the NF-[Formula: see text]B binding site, confirmed through chromatin immunoprecipitation.

CONCLUSION

HGF induced GPX1 expression through the NF-[Formula: see text]B and Akt pathways, suggesting a central role in gastric cell proliferation and invasion. Hence, GPX1 emerges as a potential therapeutic target for gastric cancer.

The biological functions and related signaling pathways of SPON2

Spondin-2 (SPON2), also referred to as M-spondin or DIL-1, is a member of the extracellular matrix protein family known as Mindin-F-spondin (FS). SPON2 can be used as a broad-spectrum tumor marker for more than a dozen tumors, mainly prostate cancer. Meanwhile, SPON2 is also a potential biomarker for the diagnosis of certain non-tumor diseases. Additionally, SPON2 plays a pivotal role in regulating tumor metastasis and progression. In normal tissues, SPON2 has a variety of biological functions represented by promoting growth and development and cell proliferation. This paper presents a comprehensive overview of the regulatory mechanisms, diagnostic potential as a broad-spectrum biomarker, diverse biological functions, involvement in various signaling pathways, and clinical applications of SPON2.

Single-cell RNA sequencing of neurofibromas reveals a tumor microenvironment favorable for neural regeneration and immune suppression in a neurofibromatosis type 1 porcine model

Neurofibromatosis Type 1 (NF1) is one of the most common genetically inherited disorders that affects 1 in 3000 children annually. Clinical manifestations vary widely but nearly always include the development of cutaneous, plexiform and diffuse neurofibromas that are managed over many years. Recent single-cell transcriptomics profiling efforts of neurofibromas have begun to reveal cell signaling processes. However, the cell signaling networks in mature, non-cutaneous neurofibromas remain unexplored. Here, we present insights into the cellular composition and signaling within mature neurofibromas, contrasting with normal adjacent tissue, in a porcine model of NF1 using single-cell RNA sequencing (scRNA-seq) analysis and histopathological characterization. These neurofibromas exhibited classic diffuse-type histologic morphology and expected patterns of S100, SOX10, GFAP, and CD34 immunohistochemistry. The porcine mature neurofibromas closely resemble human neurofibromas histologically and contain all known cellular components of their human counterparts. The scRNA-seq confirmed the presence of all expected cell types within these neurofibromas and identified novel populations of fibroblasts and immune cells, which may contribute to the tumor microenvironment by suppressing inflammation, promoting M2 macrophage polarization, increasing fibrosis, and driving the proliferation of Schwann cells. Notably, we identified tumor-associated IDO1 +/CD274+ (PD-L1) + dendritic cells, which represent the first such observation in any NF1 animal model and suggest the role of the upregulation of immune checkpoints in mature neurofibromas. Finally, we observed that cell types in the tumor microenvironment are poised to promote immune evasion, extracellular matrix reconstruction, and nerve regeneration.

Comprehensive analysis of the oncogenic and immunological role of SPON2 in human tumors

BACKGROUND

Sapiens spondin-2 (SPON2) is a protein found in the extracellular matrix that plays a role in a number of processes, including immune reactions and cell adhesion, and is closely linked to the emergence of a number of tumor types. However, we know very little about Sapiens spondin-2. Therefore, we performed a systematic pan-carcinogenic analysis to explore the relationship between Sapiens spondin-2 and cancers.

MATERIALS AND METHODS

By comprehensive use of datasets from TCGA, GEO, GTEx, HPA, CPTAC, GEPIA2, TIMER2, cBioPortal, STRING, we adopted bioinformatics methods to dig up the potential carcinogenesis of SPON2, including dissecting the correlation between SPON2 and gene expression, prognosis, gene mutation, Immunohistochemistry staining, immune cell infiltration, and constructed the interaction network of a total of 54 SPON2-binding proteins as well as explored the enrichment analysis of SPON2-related partners.

RESULTS

The expression of Sapiens spondin-2 in most tumor tissues was higher than that of normal tissues. In addition, SPON2 showed the early diagnostic value in 33 kinds of tumors and was positively or negatively associated with the prognosis of different tumors. It also validates that SPON2 is the gene associated with the majority of immune-infiltrating cells in pan-cancer. High SPON2 expression is associated with tumor progression related pathways.

CONCLUSION

We found and validated the potential use of SPON2 in cancer detection for the first time through pan-cancer analysis. The expression levels of SPON2 in various tumors were quite different from those in normal tissues. Furthermore, the performance of SPON2 in tumorigenesis and tumor immunity verified our hypothesis. At the same time, it has high specificity and sensitivity in cancer detection. Therefore, SPON2 can be employed as an auxiliary index for the initial diagnosis of tumors and a prognostic marker for various types of tumors.

MACC1-induced migration in tumors: Current state and perspective

Malignant tumors are still a global, heavy health burden. Many tumor types cannot be treated curatively, underlining the need for new treatment targets. In recent years, metastasis associated in colon cancer 1 (MACC1) was identified as a promising biomarker and drug target, as it is promoting tumor migration, initiation, proliferation, and others in a multitude of solid cancers. Here, we will summarize the current knowledge about MACC1-induced tumor cell migration with a special focus on the cytoskeletal and adhesive systems. In addition, a brief overview of several in vitro models used for the analysis of cell migration is given. In this context, we will point to issues with the currently most prevalent models used to study MACC1-dependent migration. Lastly, open questions about MACC1-dependent effects on tumor cell migration will be addressed.

CAF signature predicts the prognosis of colorectal cancer patients: A retrospective study based on bulk RNA sequencing and single-cell RNA sequencing data

The incidence rate and mortality rate of colorectal cancer (CRC) ranks third and second globally. Cancer-associated fibroblasts (CAFs) are the major constituent of the stromal cells in the tumor microenvironment (TME) and are closely associated with patients' prognoses. Our study intended to establish a prognostic model for CRC using hallmark genes of CAFs. The expression values of genes and clinicopathological characteristics of patients were enrolled from the cancer genome atlas database as well as the gene expression omnibus database. The single-cell RNA sequencing data were collected and analyzed in the deeply integrated human single-cell omics database and cancer single-cell expression map databases. The ESTIMATE algorithm was applied to access the infiltration levels of immune and stromal cells. The prognostic genes were selected by the Cox regression analysis and the prognostic signature was constructed by the least absolute shrinkage and selection operator algorithm. gene set enrichment analysis was used to explore the enriched gene sets. In this study, based on bulk RNA sequencing and single-cell RNA sequencing data, and we found that more CAFs were infiltrated in the tumor microenvironment and consisted of 3 subtypes. Then we constructed a prognostic signature for CRC using hallmark genes of CAFs and proved that this signature exhibited high values to predict the overall survival of CRC patients in independent training and validating cohorts. Besides, function enrichment analysis revealed that our prognostic model was significantly associated with immune regulation. Further analysis showed that the infiltrated levels of tumor-suppressing immune cells and the expression of higher immune checkpoint genes in CRC tissues were higher in patients with high-risk scores. Furthermore, immunohistochemistry analysis exhibited that these genes in our prognostic signature were markedly upregulated in CRC tissues. We first constructed a signature based on CAFs hallmark genes to predict the survival of CRC patients and further revealed that the tumor-suppressing microenvironment and dysregulated immune checkpoint genes in CRC tissues were partly responsible for the poor prognosis of patients.

Rab27b, a Regulator of Exosome Secretion, Is Associated With Peritoneal Metastases in Gastric Cancer

BACKGROUND/AIM

Peritoneal metastasis (PM) of gastric cancer (GC) leads to poor clinical outcomes. Tumor-derived exosomes promote metastasis via communication between tumor cells and host cells. In this study, we investigated the effect of Rab27, which is required for exosome secretion, on the PM of GC.

MATERIALS AND METHODS

We established a stable knockdown of two Rab27 homologs, Rab27a and Rab27b, in human GC cells (58As9) with a high potential of PM. We examined the level of exosome secretion from Rab27-knockdown 58As9 cells by Western blotting and the ability of Rab27b knockdown to suppress PM in 58As9 cells using a mouse xenograft model. In vitro proliferation and invasion assays were performed in the Rab27b-knockdown cells. Next, Rab27b expression was evaluated in human GC tissues by immunohistochemistry. Finally, we assessed the clinicopathological and prognostic significance of Rab27b expression by RT-qPCR in both our and other TCGA datasets of GC.

RESULTS

Rab27a and Rab27b knockdown in 58As9 cells decreased the secretion of exosomes, characterized by the endocytic marker CD63. Rab27b knockdown decreased PM in vivo without affecting the in vitro proliferation or invasion ability of 58As9 cells. In human GC tissues, Rab27b was overexpressed in tumor cells. The overall and recurrence-free survival rates were significantly lower in GC patients with high compared to low Rab27b mRNA expression in our and other TCGA datasets.

CONCLUSION

Rab27b expression potentially serves as a poor prognostic biomarker, possibly affecting PM via exosome secretion from GC cells.

Serum Spondin-2 expression, tumor invasion, and antitumor immune response in patients with cervical cancer

BACKGROUND

Cervical cancer is a gynecological malignancy common in middle-aged and older patients, with a high mortality rate. Spondin-2 is an extracellular matrix protein that involved in innate and acquired immune responses. Herein, we investigated the relationship between serum Spondin-2 expression, tumor invasion and infiltration, and immune response in patients with cervical cancer and provided a theoretical basis for clinical practice.

AIM

To investigate the relationship between serum Spondin-2 expression and cervical cancer-related indicators.

METHODS

Overall, 147 patients with cervical cancer who were admitted to our institution between January 2019 and August 2019 were assigned to the cervical cancer group, and 92 patients with benign uterine lesions and 86 healthy individuals were assigned to the benign and control groups, respectively. In each group, serum Spondin-2 expression was measured, and the receiver operating characteristic (ROC) curve was determined. Patients with cervical cancer were classified into high or low Spondin-2 groups depending on the Spondin-2 threshold value used for diagnosing cervical cancer. Patient’s clinical data were collected to compare the clinicopathologic characteristics, immune cytokine levels, and prognosis of patients with varying Spondin-2 expression levels.

RESULTS

The expression level of serum Spondin-2 was significantly higher in the cervical cancer group than in the benign and control groups (P < 0.05). According to the ROC curve, the cutoff value of Spondin-2 used in the diagnosis of cervical carcinoma was 25.68 ± 7.11 μg/L. The proportion of patients with Federation of Gynecology and Obstetrics stage III, nerve invasion, vascular invasion, and lymph node metastasis was higher in the high Spondin-2 group than in the low Spondin-2 group (P < 0.05). Interleukin-5 (IL-5) and IL-4 Levels were higher in the high Spondin-2 group than in the low Spondin-2 group. In contrast, IL-2 and tumor necrosis factor-α levels were lower in the high Spondin-2 group than in the low Spondin-2 group (P < 0.05). After 3 years of follow-up, progression-free survival and overall survival were significantly shorter in the high Spondin-2 group than in the low Spondin-2 group (P < 0.05).

CONCLUSION

The expression of serum Spondin-2 is upregulated in patients with cervical carcinoma and is related to tumor invasion and infiltration, antitumor immune response, and prognosis.

Tumor-derived exosomal HOTAIRM1 regulates SPON2 in CAFs to promote progression of lung adenocarcinoma

OBJECTIVE

SPON2 is one of the extracellular matrix proteins, which is closely related to the progression of a variety of tumors including non-small cell lung cancer (NSCLC), but its upstream regulation mechanism remains unclear. Our research aims to find the specific regulatory pathway of SPON2 by exploring the potential crosstalk between tumor cells and cancer-associated fibroblasts (CAFs) in tumor microenvironment (TME) of NSCLC.

METHODS

We analyzed T1 lung adenocarcinoma samples from TCGA and screened extracellular matrix proteins that indicate poor prognosis. Expression level of SPON2 was verified by qPCR in clinical samples. The exosomes of NSCLC cell supernatant were extracted and identified by nanoparticle tracking analysis (NTA) and transmission electron microscope, western blots. The exosomes and CAFs were co-cultured, and cell migration and Matrigel invasion assay were used to evaluate the effect of CAFs on the migration and invasion of NSCLC cells. The interaction between LncRNA and miRNA was verified by Targetscan prediction, luciferase reporter assay, and RNA binding protein immunoprecipitation (RIP).

RESULTS

We found that the expression of SPON2 was up-regulated in clinical T1a stage NSCLC patients. The expression of lnc HOTAIRM1 (HOTAIRM1) in exosomes secreted by NSCLC tissues increased. After exosomal HOTAIRM1 entered CAFs, HOTAIRM1 can adsorb miR-328-5p to up-regulate the expression of SPON2 in CAFs. Up-regulation of SPON2 in CAFs could promote the migration and invasion of NSCLC cells.

CONCLUSION

Tumor-derived exosomal HOTAIRM1 can transfer into CAFs and competitively adsorb miR-328-5p, and regulate the SPON2 expression of CAFs cells, ultimately promote the progression of NSCLC. The discovery of this regulatory pathway can provide a new potential therapeutic target for the diagnosis and treatment of NSCLC.

Cancer Stem Cells and the Tumor Microenvironment in Gastric Cancer

Gastric cancer (GC) remains one of the leading causes of cancer-related death worldwide. Cancer stem cells (CSCs) might be responsible for tumor initiation, relapse, metastasis and treatment resistance of GC. The tumor microenvironment (TME) comprises tumor cells, immune cells, stromal cells and other extracellular components, which plays a pivotal role in tumor progression and therapy resistance. The properties of CSCs are regulated by cells and extracellular matrix components of the TME in some unique manners. This review will summarize current literature regarding the effects of CSCs and TME on the progression and therapy resistance of GC, while emphasizing the potential for developing successful anti-tumor therapy based on targeting the TME and CSCs.