Many inflammatory mediators are involved in the process of carcinogenesis and cancer progression. In addition to cytokines and chemokines, lipid mediators have recently attracted attention as ...signaling molecules associated with inflammatory diseases. Sphingosine‐1‐phosphate (S1P) is a pleiotropic lipid mediator that regulates cell survival and migration, immune cell recruitment, angiogenesis and lymphangiogenesis. S1P also plays a significant role in inflammation and cancer. The gradation of S1P concentration in the blood, lymph and tissue regulates lymphocyte trafficking, an important component of inflammation. Furthermore, cancer cells produce elevated levels of S1P, contributing to the tumor microenvironment and linking cancer and inflammation. Future technological advances may reveal greater detail about the mechanisms of S1P regulation in the tumor microenvironment and the contribution of S1P to cancer progression. Considering the critical role of S1P in linking inflammation and cancer, it is possible that the S1P signaling pathway could be a novel therapeutic target for cancers with chronic inflammation.
Sphingosine‐1‐phosphate (S1P) is a pleiotropic lipid mediator that regulates cell survival and migration, immune cell recruitment, angiogenesis and lymphangiogenesis. Cancer cells produce elevated levels of S1P, contributing to the tumor microenvironment and linking cancer and inflammation. Considering the critical role of S1P in linking inflammation and cancer, it is possible that the S1P signaling pathway could be a novel therapeutic target for cancers with chronic inflammation.
Next generation sequencing (NGS) has been an invaluable tool to put genomic sequencing into clinical practice. The incorporation of clinically relevant target sequences into NGS‐based gene panel ...tests has generated practical diagnostic tools that enable individualized cancer‐patient care. The clinical utility of gene panel testing includes investigation of the genetic basis for an individual's response to therapy, such as signaling pathways associated with a response to specific therapies, microsatellite instability and a hypermutated phenotype, and deficiency in the DNA double‐strand break repair pathway. In this review, we describe the concept of precision cancer medicine using target sequences in gene panel tests as well as the importance of the control of sample quality in routine NGS‐based genomic testing. We describe geographic and ethnic differences in cancer genomes, and discuss issues that need to be addressed in the future based on our experiences in Japan.
The incorporation of clinically relevant target sequences into next generation sequencing (NGS)‐based gene panel tests has generated practical diagnostic tools that enable individualized cancer‐patient care. In this review, we describe the concept of precision cancer medicine using target sequences in gene panel tests as well as the importance of the control of sample quality in routine NGS‐based genomic testing. We describe geographic and ethnic differences in cancer genomes, and discuss issues that need to be addressed in the future based on our experiences in Japan.
While cancer cells gain aggressiveness by mutations, abundant mutations release neoantigens, attracting anti-cancer immune cells. We hypothesized that in breast cancer (BC), where mutation is less ...common, tumors with high mutation rates demonstrate aggressive phenotypes and attract immune cells simultaneously. High mutation rates were defined as the top 10% of the mutation rate, utilizing TCGA and METABRIC transcriptomic data. Mutation rate did not impact survival although high mutation BCs were associated with aggressive clinical features, such as more frequent in ER-negative tumors (p < 0.01), in triple-negative subtype (p = 0.03), and increased MKI-67 mRNA expression (p < 0.01) in both cohorts. Tumors with high mutation rates were associated with APOBEC3B and homologous recombination deficiency, increasing neoantigen loads (all p < 0.01). Cell proliferation and immune activity pathways were enriched in BCs with high mutation rates. Furthermore, there were higher lymphocytes and M1 macrophage infiltration in high mutation BCs. Additionally, T-cell receptor diversity, cytolytic activity score (CYT), and T-cell exhaustion marker expression were significantly elevated in BCs with high mutation rates (all p < 0.01), indicating strong immunogenicity. In conclusion, enhanced immunity due to neoantigens can be one of possible forces to counterbalance aggressiveness of a high mutation rate, resulting in similar survival rates to low mutation BCs.
Background
Tumor mutational burden-high (TMB-H), which is detected with gene panel testing, is a promising biomarker for immune checkpoint inhibitors (ICIs) in colorectal cancer (CRC). However, in ...clinical practice, not every patient is tested for TMB-H using gene panel testing. We aimed to identify the histopathological characteristics of TMB-H CRC for efficient selection of patients who should undergo gene panel testing. Moreover, we attempted to develop a convolutional neural network (CNN)-based algorithm to predict TMB-H CRC directly from hematoxylin and eosin (H&E) slides.
Methods
We used two CRC cohorts tested for TMB-H, and whole-slide H&E digital images were obtained from the cohorts. The Japanese CRC (JP-CRC) cohort (
N
= 201) was evaluated to detect the histopathological characteristics of TMB-H using H&E slides. The JP-CRC cohort and The Cancer Genome Atlas (TCGA) CRC cohort (
N
= 77) were used to develop a CNN-based TMB-H prediction model from the H&E digital images.
Results
Tumor-infiltrating lymphocytes (TILs) were significantly associated with TMB-H CRC (
P
< 0.001). The area under the curve (AUC) for predicting TMB-H CRC was 0.910. We developed a CNN-based TMB-H prediction model. Validation tests were conducted 10 times using randomly selected slides, and the average AUC for predicting TMB-H slides was 0.934.
Conclusions
TILs, a histopathological characteristic detected with H&E slides, are associated with TMB-H CRC. Our CNN-based model has the potential to predict TMB-H CRC directly from H&E slides, thereby reducing the burden on pathologists. These approaches will provide clinicians with important information about the applications of ICIs at low cost.
Recent progress in cancer genome analysis using next-generation sequencing has revealed a high mutation burden in some tumors. The particularly high rate of somatic mutation in these tumors ...correlates with the generation of neo-antigens capable of eliciting an immune response. Identification of hypermutated tumors is therefore clinically valuable for selecting patients suitable for immunotherapy treatment. There are several known causes of hypermutation in tumors, such as ultraviolet light in melanoma, tobacco smoke in lung cancer, and excessive APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like) activity in breast and gastric cancer. In gastrointestinal cancers, one of the leading causes of hypermutation is a defect in DNA mismatch repair, which results in microsatellite instability (MSI). This review will focus on the frequency, characteristics and genomic signature of hypermutated gastrointestinal cancers with MSI. Detection of tumor hypermutation in cancer is expected to not only predict the clinical benefit of immune checkpoint inhibitor treatment, but also to provide better surgical strategies for the patients with hypermutated tumors. Thus, in an era of precision medicine, identification of hypermutation and MSI will play an important role directing surgical and chemotherapeutic treatment.
Angiogenesis is one of the hallmarks of cancer. We hypothesized that intra-tumoral angiogenesis correlates with inflammation and metastasis in breast cancer patients. To test this hypothesis, we ...generated an angiogenesis pathway score using gene set variation analysis and analyzed the tumor transcriptome of 3999 breast cancer patients from The Cancer Genome Atlas Breast Cancer (TCGA-BRCA), Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), GSE20194, GSE25066, GSE32646, and GSE2034 cohorts. We found that the score correlated with expression of various angiogenesis-, vascular stability-, and sphingosine-1-phosphate (S1P)-related genes. Surprisingly, the angiogenesis score was not associated with breast cancer subtype, Nottingham pathological grade, clinical stage, response to neoadjuvant chemotherapy, or patient survival. However, a high score was associated with a low fraction of both favorable and unfavorable immune cell infiltrations except for dendritic cell and M2 macrophage, and with Leukocyte Fraction, Tumor Infiltrating Lymphocyte Regional Fraction and Lymphocyte Infiltration Signature scores. High-score tumors had significant enrichment for unfavorable inflammation-related gene sets (interleukin (IL)6, and tumor necrosis factor (TNF)α- and TGFβ-signaling), as well as metastasis-related gene sets (epithelial mesenchymal transition, and Hedgehog-, Notch-, and WNT-signaling). High score was significantly associated with metastatic recurrence particularly to brain and bone. In conclusion, using the angiogenesis pathway score, we found that intra-tumoral angiogenesis is associated with immune reaction, inflammation and metastasis-related pathways, and metastatic recurrence in breast cancer.
Although obesity with associated inflammation is now recognized as a risk factor for breast cancer and distant metastases, the functional basis for these connections remain poorly understood. Here, ...we show that in breast cancer patients and in animal breast cancer models, obesity is a sufficient cause for increased expression of the bioactive sphingolipid mediator sphingosine-1-phosphate (S1P), which mediates cancer pathogenesis. A high-fat diet was sufficient to upregulate expression of sphingosine kinase 1 (SphK1), the enzyme that produces S1P, along with its receptor S1PR1 in syngeneic and spontaneous breast tumors. Targeting the SphK1/S1P/S1PR1 axis with FTY720/fingolimod attenuated key proinflammatory cytokines, macrophage infiltration, and tumor progression induced by obesity. S1P produced in the lung premetastatic niche by tumor-induced SphK1 increased macrophage recruitment into the lung and induced IL6 and signaling pathways important for lung metastatic colonization. Conversely, FTY720 suppressed IL6, macrophage infiltration, and S1P-mediated signaling pathways in the lung induced by a high-fat diet, and it dramatically reduced formation of metastatic foci. In tumor-bearing mice, FTY720 similarly reduced obesity-related inflammation, S1P signaling, and pulmonary metastasis, thereby prolonging survival. Taken together, our results establish a critical role for circulating S1P produced by tumors and the SphK1/S1P/S1PR1 axis in obesity-related inflammation, formation of lung metastatic niches, and breast cancer metastasis, with potential implications for prevention and treatment.
These findings offer a preclinical proof of concept that signaling by a sphingolipid may be an effective target to prevent obesity-related breast cancer metastasis.
.
Bile duct obstruction is a potent stimulus for cholangiocyte proliferation, especially for large cholangiocytes. Our previous studies reported that conjugated bile acids (CBAs) activate the protein ...kinase B (AKT) and extracellular signal‐regulated kinase 1 and 2 (ERK1/2) signaling pathways through sphingosine 1‐phosphate receptor (S1PR) 2 in hepatocytes and cholangiocarcinoma cells. It also has been reported that taurocholate (TCA) promotes large cholangiocyte proliferation and protects cholangiocytes from bile duct ligation (BDL)‐induced apoptosis. However, the role of S1PR2 in bile‐acid–mediated cholangiocyte proliferation and cholestatic liver injury has not been elucidated. Here, we report that S1PR2 is the predominant S1PR expressed in cholangiocytes. Both TCA‐ and sphingosine‐1‐phosphate (S1P)‐induced activation of ERK1/2 and AKT were inhibited by JTE‐013, a specific antagonist of S1PR2, in cholangiocytes. In addition, TCA‐ and S1P‐induced cell proliferation and migration were inhibited by JTE‐013 and a specific short hairpin RNA of S1PR2, as well as chemical inhibitors of ERK1/2 and AKT in mouse cholangiocytes. In BDL mice, expression of S1PR2 was up‐regulated in whole liver and cholangiocytes. S1PR2 deficiency significantly reduced BDL‐induced cholangiocyte proliferation and cholestatic injury, as indicated by significant reductions in inflammation and liver fibrosis in S1PR2 knockout mice. Treatment of BDL mice with JTE‐013 significantly reduced total bile acid levels in serum and cholestatic liver injury. Conclusion: This study suggests that CBA‐induced activation of S1PR2‐mediated signaling pathways plays a critical role in obstructive cholestasis and may represent a novel therapeutic target for cholestatic liver diseases. (Hepatology 2017;65:2005‐2018).
Inflammatory bowel disease is an important risk factor for colorectal cancer. We show that sphingosine-1-phosphate (S1P) produced by upregulation of sphingosine kinase 1 (SphK1) links chronic ...intestinal inflammation to colitis-associated cancer (CAC) and both are exacerbated by deletion of Sphk2. S1P is essential for production of the multifunctional NF-κB-regulated cytokine IL-6, persistent activation of the transcription factor STAT3, and consequent upregulation of the S1P receptor, S1PR1. The prodrug FTY720 decreased SphK1 and S1PR1 expression and eliminated the NF-κB/IL-6/STAT3 amplification cascade and development of CAC, even in Sphk2−/− mice, and may be useful in treating colon cancer in individuals with ulcerative colitis. Thus, the SphK1/S1P/S1PR1 axis is at the nexus between NF-κB and STAT3 and connects chronic inflammation and CAC.
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► SphK1 upregulation and S1P lead to sustained activation of NF-κB, STAT3, and CAC ► SphK1/S1P/S1PR1 axis controls the NF-κB/IL-6/STAT3 amplification cascade and CAC ► SphK1 and S1P link chronic intestinal inflammation and cancer ► FTY720 treatment at late stages of CAC blocks carcinoma progression
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