Myofibroblasts are associated with the progression of scirrhous gastric carcinoma

Tumor microenvironment characteristics of lipid metabolism reprogramming related to ferroptosis and EndMT influencing prognosis in gastric cancer

BACKGROUND

Gastric cancer (GC) is a refractory malignant tumor with high tumor heterogeneity, a low rate of early diagnosis, and poor patient prognosis. Lipid metabolism reprogramming plays a critical role in tumorigenesis and progression, but its prognostic role and regulatory mechanism in GC are rarely studied. Thus, the identification of signatures related to lipid metabolism is necessary and may present a new avenue for improving the overall prognosis of GC.

METHODS

Lipid metabolism-associated genes (LMAGs) with differential expression in tumor and tumor-adjacent tissue were acquired to identify lipid metabolism-associated subtypes. The differentially expressed genes (DEGs) between the two clusters were then utilized for prognostic analysis and signature construction. Additionally, pathway enrichment analysis and immune cell infiltration analysis were employed to identify the characteristics of the prognostic model. Further analyses were conducted at the single-cell level to better understand the model's prognostic mechanism. Finally, the prediction of immunotherapy response was used to suggest potential treatments.

RESULTS

Two lipid metabolism-associated subtypes were identified and 9 prognosis-related genes from the DEGs between the two clusters were collected for the construction of the prognostic model named lipid metabolism-associated signature (LMAS). Then we found the low LMAS patients with favorable prognoses were more sensitive to ferroptosis in the Cancer Genome Atlas of Stomach Adenocarcinoma (TCGA-STAD). Meanwhile, the tumor cells exhibiting high levels of lipid peroxidation and accumulation of reactive oxygen species (ROS) in single-cell levels were primarily enriched in the low LMAS group, which was more likely to induce ferroptosis. In addition, endothelial cells and cancer-associated fibroblasts (CAFs) facilitated tumor angiogenesis, proliferation, invasion, and metastasis through endothelial-mesenchymal transition (EndMT), affecting the prognosis of the patients with high LMAS scores. Moreover, CD1C- CD141- dendritic cells (DCs) also secreted pro-tumorigenic cytokines to regulate the function of endothelial cells and CAFs. Finally, the patients with low LMAS scores might have better efficacy in immunotherapy.

CONCLUSIONS

A LMAS was constructed to guide GC prognosis and therapy. Meanwhile, a novel anti-tumor effect was found in lipid metabolism reprogramming of GC which improved patients' prognosis by regulating the sensitivity of tumor cells to ferroptosis. Moreover, EndMT may have a negative impact on GC prognosis.

Cancer-associated fibroblasts, and clinicopathological characteristics and prognosis of gastric cancer: A systematic review and meta-analysis

Objective

To systematically evaluate the relationship between cancer-associated fibroblasts (CAFs) and clinicopathological characteristics and prognosis of gastric cancer, so as to provide new directions and clinical evidence for the diagnosis and treatment of this disease.

Methods

We searched PubMed, Embase, Web of Science, and The Cochrane Library to identify studies on the correlation between tumor-associated fibroblasts and the diagnosis and prognosis of gastric cancer. Two researchers screened the literature independently to extract data, evaluated the quality of the included studies, and used the Review Manager 5.4 software to perform a meta-analysis.

Results

A total of 14 studies involving a total of 2,703 patients were included. The meta-analysis results showed that high expression of CAFs was associated with stage III-IV gastric cancer (relative risk ratio [RR]=1.59; 95% confidence interval [CI]: [1.24-2.04]; P=0.0003), lymph node metastasis (RR=1.51; 95% CI: [1.23-1.87]; P=0.0001), serosal infiltration (RR=1.56, 95% CI: [1.24-1.95]; P=0.0001), diffuse and mixed types in Lauren classification (RR=1.43; 95% CI: [1.18-1.74]; P=0.0003), vascular invasion (RR=1.99; 95% CI: [1.26-3.14]; P=0.003), and overall survival (hazard ratio [HR]=1.38; 95% CI: [1.22-1.56]; P<0.00001). However, the high expression of CAFs was not significantly correlated with poorly differentiated gastric cancer (RR=1.03; 95% CI: [0.96-1.10]; P=0.45) and gastric cancer with tumor diameter >5 cm (RR=1.34; 95% CI: [0.98-1.83]; P=0.07).

Conclusion

The findings of this meta-analysis demonstrated that high expression of CAFs is closely associated with the traditional pathological indicators related to poor prognosis in gastric cancer, and is a valuable prognostic factor in this setting.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022358165.

FAPα and αSMA mark different subsets of fibroblasts in normal kidney and conventional renal cell carcinoma

Several studies suggested a correlation between cancer associated fibroblasts (CAF) and cancer progression, but data on conventional renal cell carcinoma (cRCC) is still lacking. We aimed to analyse the impact of αSMA positive myo-CAF and FAPα expressing i-CAF on postoperative relapse of cRCC. We applied immunohistochemistry on tissue-multiarray (TMA) containing 736 consecutively operated cRCC without metastasis at the time of diagnosis. We analysed the correlation between the amount and pattern of αSMA and FAPα expressing CAFs and tumour cells and postoperative tumour relapse. Stromal fibroblasts of each cRCC displayed αSMA immunreaction but only 142 of the 736 tumours showed positive FAPα staining. There was no correlation between the amount of αSMA and or FAPα positive CAFs and tumour progression. However, tumours with large tourtous vessels with strong αSMA positive immunreaction have more then two times higher risk of postoperative tumour relapse (RR=2.198, p = 0.005). Patients with cRCC (57) showing cytoplasmic αSMA staining of tumour cells had a nearly two times higher risk for postoperative progression (RR=1.776, p = 0.014). There is no significant correlation between the density of αSMA or FAPα positive CAFs and postoperative relapse of cRCCs, therefore CAFs in cRCC are not suitable targets for therapy. Further limitation of anti-CAF therapy of cRCC that stromal cells of normal kidney are positive with αSMA antibody.

Clinicopathological significance and prognostic value of cancer-associated fibroblasts in prostate cancer patients

INTRODUCTION

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment were considered to play an essential role in tumor growth and development. However, few studies have assessed the prognostic and clinicopathological significance of CAFs in prostate cancer (PCa) patients.

METHODS

One hundred thirty pairs of PCa tissues and normal adjacent tissues (NATs) were immunostained with fibroblast activation protein and α-smooth muscle actin to quantify CAFs. Bioinformatics analysis was used to uncover the possible biological functions of CAFs.

RESULTS

More CAFs were identified in PCa tissues than in NATs. High density of CAFs may be associated with advanced-stage disease, higher Gleason scores, lymphatic metastases, higher PSA, and poor biochemical recurrence-free survival in PCa. Bioinformatics analysis showed that CAFs may regulate tumor progression and recurrence through ECM modification, PI3K-Akt signaling pathway and regulation of cytoskeleton.

CONCLUSION

In summary, our study uncovered the clinicopathological significance and potential mechanism of CAFs and indicated that CAFs may be a useful prognostic biomarker in PCa.

High COX-2 expression in cancer-associated fibiroblasts contributes to poor survival and promotes migration and invasiveness in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has the highest rate of metastasis among head and neck cancers, and distant metastasis is the major reason for treatment failure. We have previously shown that high cyclooxygenase-2 (COX-2) expression is associated with a poor prognosis of patients with NPC and inhibits chemotherapy-induced senescence in NPC cells. In this study, we found that COX-2 was upregulated in cancer-associated fibroblasts (CAFs) derived from NPC by RNA-Seq. Furthermore, elevated COX-2 expression in CAF was detected in NPC patients with poor survival and distant metastasis by using immunohistochemistry. Then, we identified that COX-2 is highly expressed in CAF at the distant metastasis site in seven paired NPC patients. High expression of COX-2 and secretion of prostaglandin E2, a major product catalyzed by COX-2 in fibroblasts, promotes migration and invasiveness of NPC cells in vitro. On the contrary, inhibition of COX-2 has the opposite effect in vitro as well as in the COX-2^-/- mouse with the lung metastasis model in vivo. Mechanistically, we discovered that COX-2 elevates tumor necrosis factor-α expression in CAF to promote NPC cell migration and invasiveness. Overall, our results identified a novel target in CAF promoting NPC metastasis. Our findings suggested that high expression of COX-2 in CAF may serve as a new prognostic indicator for NPC metastasis and provide the possibility of targeting CAF for treating advanced NPC.

Scaffold-Assisted Ectopic Transplantation of Internal Organs and Patient-Derived Tumors

Xenotransplantation of human tissues into immunodeficient mice has emerged as an invaluable preclinical model to study human biology and disease progression and predict clinical response. The most common anatomical site for tissue transplantation is the subcutaneous pocket due to simple surgical procedures and accessibility for gross monitoring and advanced imaging modalities. However, subcutaneously implanted tissues initially experience a sharp change in oxygen and nutrient supply and increased mechanical deformation. During this acute phase of tissue integration to the host vasculature, substantial cell death and tissue fibrosis occur limiting engraftment efficiency. Previously, we demonstrated that the implantation of inverted colloidal crystal hydrogel scaffolds triggers proangiogenic and immunomodulatory functions without characteristic foreign body encapsulation. In this study, we examine the use of this unique host response to improve the ectopic transplantation of tissues to the subcutaneous site. Scaffold-assisted tissues preserved morphological features and blood vessel density compared to native tissues, whereas scaffold-free tissues collapsed and were less vascularized. Notably, the supporting biomaterial scaffold modulated the foreign body response to reduce the localization of Ly6G⁺ cells within the transplanted tissues. Cotransplantation of patient-derived gastric cancer with a scaffold resulted in a comparable level of engraftment to conventional methods; however, detailed immunohistological characterization revealed significantly better retention of proliferative cells (Ki67⁺) and human immune cells (CD45⁺) by the end of the study. We envision that leveraging the immunomodulatory properties of biomaterial interfaces can be an attractive strategy to improve the functional engraftment of xenotransplants and accelerate individualized diagnostics and the development of novel therapeutic strategies.

Stromal markers of activated tumor associated fibroblasts predict poor survival and are associated with necrosis in non-small cell lung cancer

OBJECTIVES

Tumor associated fibroblasts (TAFs) are essential contributors of the progression of non-small cell lung cancer (NSCLC). Most lung TAFs exhibit an activated phenotype characterized by the expression of α-SMA and fibrillar collagens. However, the prognostic value of these activation markers in NSCLC remains unclear.

MATERIAL AND METHODS

We conducted a quantitative image analysis of α-SMA immunostaining and picrosirius red staining of fibrillar collagens imaged by bright-field and polarized microscopy, respectively, using tissue microarrays with samples from 220 surgical patients, which elicited a percentage of positive staining area for each marker and patient.

RESULTS

Kaplan-Meier curves showed that all TAF activation markers were significantly associated with poor survival, and their prognostic value was independent of TNM staging as revealed by multivariate analysis, which elicited an adjusted increased risk of death after 3 years of 129% and 94% for fibrillar collagens imaged with bright-field (p = 0.004) and polarized light (p = 0.003), respectively, and of 89% for α-SMA (p = 0.009). We also found a significant association between all TAF activation markers and tumor necrosis, which is often indicative of hypoxia, supporting a pathologic link between tumor desmoplasia and necrosis/hypoxia.

CONCLUSIONS

Our findings identify patients with large histologic coverage of fibrillar collagens and α-SMA + TAFs to be at higher risk of recurrence and death, supporting that they could be considered for adjuvant therapy.

Establishment of a New Scirrhous Gastric Cancer Cell Line with FGFR2 Overexpression, OCUM-14

BACKGROUND

The prognosis of scirrhous gastric carcinoma (SGC), which is characterized by rapid infiltration and proliferation of cancer cells accompanied by extensive stromal fibrosis, is extremely poor. In this study, we report the establishment of a unique SGC cell line from a gastric cancer patient in whom an autopsy was performed.

METHODS

A new SGC cell line, OCUM-14, was established from malignant ascites of a male patient with SGC. A postmortem autopsy was performed on the patient. Characterization of OCUM-14 cells was analyzed by microscopic examination, reverse transcription polymerase chain reaction, fluorescence in situ hybridization analysis, immunohistochemical examination, CCK-8 assay, and in vivo assay.

RESULTS

OCUM-14 cells grew singly or in clusters, and were floating and round-shaped. Most OCUM-14 cells had many microvilli on their surfaces. The doubling time was 43.1 h, and the subcutaneous inoculation of 1.0 × 10⁷ OCUM-14 cells into mice resulted in 50% tumor formation. mRNA expressions of fibroblast growth factor receptor 2 (FGFR2) and human epidermal growth factor receptor 2 (HER2) were observed in OCUM-14 cells. FGFR2, but not HER2, overexpression was found in OCUM-14 cells. The heterogeneous overexpression of FGFR2 was also found in both the primary tumor and metastatic lesions of the peritoneum, lymph node, bone marrow, and lung of the patient. The FGFR2 inhibitors AZD4547 and BGJ398 significantly decreased the growth of OCUM-14 cells, while paclitaxel and 5-fluorouracil significantly decreased the proliferation of OCUM-14 cells, but cisplatin did not.

CONCLUSION

A new gastric cancer cell line, OCUM-14, was established from SGC and showed FGFR2 overexpression. OCUM-14 might be useful for elucidating the characteristic mechanisms of SGC and clarifying the effect of FGFR2 inhibitors on SGC.

Overexpression of α-sma-positive fibroblasts (CAFs) in Nasopharyngeal Carcinoma Predicts Poor Prognosis

Purpose: The aim of this study is to investigate the differential expression of α-sma-positive fibroblasts (CAFs) in nasopharyngeal carcinomas (NPCs), nasopharyngitis, metastatic tissues of NPCs and its prognostic value in NPCs.

Methods: The expression of α-sma-labeled CAFs in 85 NPCs, 32 nasopharyngitis and 12 metastatic tissues of NPCs was detected by immunohistochemical method. The relationship between CAFs and clinicopathological parameters of NPCs was analyzed.

Results: The high density of CAFs in the NPCs, nasopharyngitis and metastatic tissues of NPCs group were 41.2% (35/85), 6.2% (2/32) and 83.3% (10/12), and a significant difference was showed among these three groups (P<0.05). Chi-square test showed that there was no significant correlation between the density of CAFs and gender, age, N stage, treatment (P>0.05), but closely correlated with T stage and relapse (P<0.05). Kaplan-Meier survival analysis showed that the mean overall survival of high-density and low-density CAFs was 86.8 months and 127.0 months, respectively. Correspondingly, the 5-year survival rates were 57.1% (20/35) and 90.0% (45/50), and there were inversely statistical differences between two groups (P<0.05). Cox multivariate analysis showed that the density of CAFs could be used as an independent prognostic factor for the survival of NPC patients (P<0.05).

Conclusions: The density of CAFs could be closely related to the metastasis of NPCs, and also is an efficient prediction factor of poor survival in patients with NPCs.

CXCL1-Chemokine (C-X-C Motif) Receptor 2 Signaling Stimulates the Recruitment of Bone Marrow-Derived Mesenchymal Cells into Diffuse-Type Gastric Cancer Stroma

Tumor stromal cells play a critical role in the progression of diffuse-type gastric cancer (DGC). The aim of this study was to clarify where tumor stromal cells originate from and which factor(s) recruits them into the tumor stroma. Immunodeficient mice with bone marrow transplantation from the cytomegalovirus enhancer/chicken β-actin promoter-enhanced green fluorescent protein mice were used for the in vivo experiments. An in vitro study analyzed the chemotaxis-stimulating factor from DGC cells using bone marrow-derived mesenchymal cells (BM-MCs). The influences of chemokine (C-X-C motif) receptor 2 (CXCR2) inhibitor on the migration of BM-MCs were examined both in vitro and in vivo. BM-MCs frequently migrated into stroma of DGC in vivo. The number of migrating BM-MCs was increased by conditioned medium from DGC cells. CXCL1 from DGC cells stimulated the chemoattractant ability of BM-MCs. Both anti-CXCL1 antibody and CXCR2 inhibitor decreased the migration of BM-MCs, stimulated by DGC cells. A CXCR2 inhibitor, SB225002, reduced the recruitment of BM-MCs into the tumor microenvironment in vivo, decreasing tumor size and lymph node metastasis, and prolonging the survival of gastric tumor-bearing mice. These findings suggested that most tumor stromal cells in DGC might originate from BM-MCs. CXCL1 from DGC cells stimulates the recruitment of BM-MCs into tumor stroma via CXCR2 signaling of BM-MCs. Inhibition of BM-MC recruitment via the CXCL1-CXCR2 axis appears a promising therapy for DGC.

Stromal Myofibroblasts Are Associated with Poor Prognosis in Solid Cancers: A Meta-Analysis of Published Studies

Objective

Published studies have evaluated the impact of stromal myofibroblasts on prognosis in solid cancers. However, the results of these studies remain controversial. We therefore performed a meta-analysis to address this issue.

Methods

The PubMed, ISI Web of Science and Embase databases were searched through November 30^th, 2015 by two investigators, and a total of 17 studies that contained 2606 patients were included. Stromal myofibroblasts were quantified in solid cancers using α-smooth muscle actin staining. Pooled Odds Ratio with 95% Confidence Intervals were calculated, and publication bias was analyzed.

Results

The results of this study suggest that in solid cancers, a high density of stromal myofibroblasts is significantly associated with poor 3- and 5-year overall survival (pooled odds ratio (95% confidence interval): 1.33 (1.10–1.60) for 3-year overall survival and 1.68 (1.22–2.32) for 5-year overall survival). In addition, a high density of stromal myofibroblasts also predicted poor 3- and 5-year disease-free survival (1.30 (1.05–1.60) for 3-year disease-free survival and 1.36 (1.01–1.83) for 5-year disease-free survival). However, stromal myofibroblasts were not associated with 3- and 5-year cancer-specific survival. No publication bias was found for all analyses.

Conclusions

The results of this study suggest that a high density of stromal myofibroblasts is associated with poor survival in solid cancers. More studies were required to investigate the prognostic value of stromal myofibroblasts in different types of solid cancers.

Bone marrow-derived stromal cells are associated with gastric cancer progression

Background:

The aim of this study was to clarify the role of bone marrow-derived stromal cells (BM-SCs) expressing CD271 in the development of gastric cancer.

Methods:

The effect of human BM-SCs on the proliferation and motility of six gastric cancer cell lines, OCUM-2M, OCUM-2MD3, OCUM-12, KATO-III, NUGC-3, and MKN-74, was examined. CD271 expression levels in BM-SCs were analysed by flow cytometry. We also generated a gastric tumour model by orthotopic inoculation of OCUM-2MLN cells in mice that had received transplantation of bone marrow from the CAG-EGFP mice. The correlation between the clinicopathological features of 279 primary gastric carcinomas and CD271 expression in tumour stroma was examined by immunohistochemistry.

Results:

Numerous BM-SCs infiltrated the gastric tumour microenvironment; CD271 expression was found in ∼25% of BM-SCs. Conditioned medium from BM-SCs significantly increased the proliferation of gastric cancer cell lines. Furthermore, conditioned medium from gastric cancer cells significantly increased the number of BM-SCs, whereas migration of OCUM-12 and NUGC-3 cells was significantly increased by conditioned medium from BM-SCs. CD271 expression in stromal cells was significantly associated with macroscopic type-4 cancers, diffuse-type tumours, and tumour invasion depth. The overall survival of patients (n=279) with CD271-positive stromal cells was significantly worse compared with that of patients with CD271-negative stromal cells. This is the first report of the significance of BM-SCs in gastric cancer progression.

Conclusions:

Bone marrow-derived stromal cells might have an important role in gastric cancer progression, and CD271-positive BM-SCs might be a useful prognostic factor for gastric cancer patients.

Transforming growth factor-β1 and α-smooth muscle actin in stromal fibroblasts are associated with a poor prognosis in patients with clinical stage I-IIIA nonsmall cell lung cancer after curative resection

The aims of this study were to investigate the expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in surgical resection specimens from nonsmall cell lung cancer (NSCLC) and to evaluate the prognostic significance of this gene expression in stromal fibroblasts for patients with clinical stage I-IIIA NSCLC. The immunohistochemical expression of TGF-β1 and α-SMA was evaluated in 78 formalin-fixed paraffin-embedded tumor specimens from clinical stage I-IIIA NSCLC. Correlations between this gene expression and the clinicopathologic characteristics were determined by chi-square test. The prognostic impact of this gene expression in stromal fibroblasts with regard to overall survival (OS) was determined by Kaplan-Meier and Cox hazard proportional model. The percentages of high TGF-β1 expression in stromal fibroblasts and cancer cells were 19.2 % (15/78) and 35.9 % (28/78), respectively. There were 28.2 % (22/78) of patients with high α-SMA expression in stromal fibroblasts. The analysis revealed a significant positive association between TGF-β1 expression in stromal fibroblasts and in cancer cells (χ (2) = 4.86, p = 0.03). No significant association was found between TGF-β1 in cancer cells and α-SMA expression in stromal fibroblasts (χ (2) = 0.978, p = 0.326). The 3-year OS rates with low and high TGF-β1 expression in stromal fibroblasts were 52.4 and 26.7 %, respectively (χ (2) = 5.42, p = 0.019). The 3-year OS rates with low and high α-SMA expression in stromal fibroblasts were 53.9 and 31.0 %, respectively (χ (2) =5.01, p=0.025). The multivariate analysis revealed that clinical stage and TGF-β1 and α-SMA expression levels in stromal fibroblasts were identified as independent predictive factors of OS. The results suggest that the expression level of TGF-β1 and α-SMA in stromal fibroblasts may have prognostic significance in patients with clinical stage I-IIIA NSCLC after curative resection.

Functional subsets of mesenchymal cell types in the tumor microenvironment

In the field of tumor biology, increasing attention is now focused on the complex interactions between various constituent cell types within the tumor microenvironment as being functionally important for the etiology of the disease. The detailed description of tumor-promoting properties of cancer-associated fibroblasts, endothelial cells, pericytes, and immune cells, introduces novel potential drug targets for improved cancer treatments, as well as a rationale for exploring the tumor stroma as a previously unchartered source for prognostic or predictive biomarkers. However, recent work highlights the fact that cellular identity is perhaps too broadly defined and that subdivision of each cell type may reveal functionally distinct subsets of cells. Here, we will review our current understanding of the diversity of different subsets of mesenchymal cells, i.e., cancer-associated fibroblasts and pericytes, residing within the tumor parenchyma.

Cancer-associated orthotopic myofibroblasts stimulates the motility of gastric carcinoma cells

Tumor progression has been recognized as the product of evolving crosstalk between cancer cells and the surrounding stromal cells. Cancer-associated orthotopic myofibroblasts may be linked to the progression of gastric carcinomas. To understand the significance of orthotopic myofibroblasts, we examined the effects of cancer-associated orthotopic myofibroblasts on the malignant phenotype of gastric cancer cells. Three human gastric cancer cell lines (OCUM-2MD3, OCUM-12, MKN-45) and four human gastric fibroblast cell lines (cancer-associated orthotopic fibroblast [CaF]-29, CaF-33, normal orthotopic fibroblast [NF]-29, NF-33) were used. The cancer-associated orthotopic fibroblast cell lines CaF-29 and CaF-33 were established from a tumoral gastric wall, and normal orthotopic fibroblast NF-29 and NF-33 were established from a non-tumoral gastric wall. Fibroblasts that were α-smooth muscle actin-positive were defined as myofibroblasts. We examined the effects of cancer-associated orthotopic myofibroblasts on the aggressiveness of gastric cancer cells by wound-healing assay, invasion assay, and RT-PCR. The ratios of myofibroblasts in CaF-29 (33%) and CaF-33 (46%) were significantly (P < 0.001) greater than those in NF-29 (11%) or NF-33 (13%). Although all four orthotopic fibroblast lines increased the motility of gastric cancer cells, including migration and invasion ability, the motility-stimulating activity of cancer-associated fibroblasts (CaF-29 and CaF-33) was significantly higher than that of normal fibroblasts (NF-29 and NF-33). These motility-stimulating activities of cancer-associated orthotopic fibroblasts were downregulated by Smad2 siRNA treatment and anti-transforming growth factor-β neutralizing antibody. These findings suggest that cancer-associated orthotopic myofibroblasts may play an important role in the progression of gastric cancers and that transforming growth factor-β produced by myofibroblasts may be one of the factors associated with the aggressiveness of gastric carcinoma cells.