Prognostic significance of S100A16 subcellular localization in lung adenocarcinoma

Novel genome-wide DNA methylation profiling reveals distinct epigenetic landscape, prognostic model and cellular composition of early-stage lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) has been a leading cause of cancer-related mortality worldwide. Early intervention can significantly improve prognosis. DNA methylation could occur in the early stage of tumor. Comprehensive understanding the epigenetic landscape of early-stage LUAD is crucial in understanding tumorigenesis.

METHODS

Enzymatic methyl sequencing (EM-seq) was performed on 23 tumors and paired normal tissue to reveal distinct epigenetic landscape, for compared with The Cancer Genome Atlas (TCGA) 450K methylation microarray data. Then, an integrative analysis was performed combined with TCGA LUAD RNA-seq data to identify significant differential methylated and expressed genes. Subsequently, the prognostic risk model was constructed and cellular composition was analyzed.

RESULTS

Methylome analysis of EM-seq comparing tumor and normal tissues identified 25 million cytosine-phosphate-guanine (CpG) sites and 30,187 differentially methylated regions (DMR) with a greater number of untraditional types. EM-seq identified a significantly higher number of CpG sites and DMRs compared to the 450K microarray. By integrating the differentially methylated genes (DMGs) with LUAD-related differentially expressed genes (DEGs) from the TCGA database, we constructed prognostic model based on six differentially methylated-expressed genes (MEGs) and verified our prognostic model in GSE13213 and GSE42127 dataset. Finally, cell deconvolution based on the in-house EM-seq methylation profile was used to estimate cellular composition of early-stage LUAD.

CONCLUSIONS

This study firstly delves into novel pattern of epigenomic DNA methylation and provides a multidimensional analysis of the role of DNA methylation revealed by EM-seq in early-stage LUAD, providing distinctive insights into its potential epigenetic mechanisms.

The role of miR-6884-5p in epithelial-mesenchymal transition in non-small cell lung cancer

Significant progress has been made in the management of non-small cell lung cancer (NSCLC), though a big barrier remains, which is epithelial-mesenchymal transition (EMT). Our study aimed to evaluate the function of miR-6884-5p and S100A16 in EMT-aggravated NSCLC. The tumor tissues and adjacent tissues from 92 NSCLC patients were collected to analyze the expression of miR-6884-5p and S100A16. Then lung cancer cell line A549 was co-transfected with miR-6884-5p mimics and S100A16 to further evaluate their function. Compared to adjacent tissues, low expression of miR-6884-5p was observed in the NSCLC tissues and associated with severe NSCLC progression. MiR-6884-5p expression was negatively correlated with EMT in NSCLC. Luciferase assay data revealed that miR-6884-5p could directly bind to the 3'UTR of S100A16 and inhibited the expression of S100A16 in A549 cells. Moreover, miR-6884-5p mimics significantly ameliorated EMT progression, and overexpression of S100A16 could reverse the inhibitory effect of miR-6884-5p in A549 cells. MiR-6884-5p inhibited EMT through directly targeting S100A16 in NSCLC. Our findings suggest that miR-6884-5p could be a diagnostic marker of NSCLC, as well as a potential candidate for NSCLC treatment.

An Update on S100A16 in Human Cancer

S100A16 is a member of the S100 protein family. S100A16 is expressed in a variety of human tissues, although at varying levels. S100A16 expression is especially high in tissues rich in epithelial cells. mRNA and protein levels of S100A16 have been reported to be differentially expressed in the majority of human cancers. Functionally, S100A16 has been linked to several aspects of tumorigenesis, for example, cell proliferation, differentiation, migration, invasion, and epithelial-mesenchymal transition (EMT). Accordingly, S100A16 has been suggested to have both tumour-promoting and suppressive roles in human cancers. S100A16-mediated cellular functions are suggested to be mediated by the regulation of various signaling pathways/proteins including EMT-related proteins E-cadherin and Vimentin, PI3K-AKT, p53, MMP1-1, MMP-2, MMP-9, JNK/p38, etc. In addition to the functional roles, expression of S100A16 has been suggested to have prognostic potential in various cancer types. The aims of this review are to summarise the expression profile, identify common molecular partners and functional roles, and explore the prognostic potential of S100A16 in human cancers.

M6A RNA methylation modification and tumor immune microenvironment in lung adenocarcinoma

Lung adenocarcinoma is one of the deadliest tumors. Studies have shown that N6-methyladenosine RNA methylation regulators, as a dynamic chemical modification, affect the occurrence and development of lung adenocarcinoma. To investigate the relationship between mutations and expression levels of m6A regulators in lung adenocarcinoma, we investigated the mutations and expression levels of 38 m6A regulators. We found that mutations in m6A regulatory factors did not affect the changes in expression levels, and 19 differentially expressed genes were identified. All tumor samples were classified into two subtypes based on the expression levels of 19 differentially expressed m6A-regulated genes. Survival analysis showed significant differences in survival between the two subtypes. To explore the relationship between immune cell infiltration and survival in both subtypes, we calculated the infiltration of 23 immune cells in both subtypes, and we found that the subtype with high immune cell infiltration had better survival. We found that subtypes with low tumor purity and high stromal and immune scores had better survival. The m6A-related immune genes were identified by taking the intersection of differentially expressed genes and immune genes in the two isoforms and calculating the Pearson correlation coefficients between the intersecting immune genes and the differentially expressed m6A-regulated genes. Finally, a prognostic model associated with m6A and associated with immunity was developed using prognostic genes screened from m6A-associated immune genes. The predictive power of the model was evaluated and our model was able to achieve good prediction.

miR-508-5p serves as an anti-oncogene by targeting S100A16 to regulate AKT signaling and epithelial-mesenchymal transition process in lung adenocarcinoma cells

BACKGROUND

Our aim was to expose the effect of miR-508-5p on the developmental and biological behaviour of lung adenocarcinoma (LUAC).

METHODS

The KM plotter was used to analyze the survival significance of miR-508-5p and S100A16 expression in LUAC patients. qRT-PCR was performed to detect the expression of miR-508-5p and S100A16 in LUAC tissue and LUAC cell lines. CCK8, colony formation and Transwell were performed to evaluate the effects of miR-508-5p and S100A16 on cell proliferation and metastasis. Dual luciferase reporter assay was used to verify that S100A16 were targets of miR-508-5p. Western blot analysis was performed to analyze protein expression.

RESULTS

Results showed that low miR-508-5p expression in LUAC tissues indicated poorer overall survival of LUAC patients and miR-508-5p was downregulated in LUAC cell lines compared to the normal human lung epithelial cell line. miR-508-5p mimics could inhibit A549 cell proliferation and metastasis abilities, while miR-508-5p Antagomir showed the opposite effect. We identified S100A16 as one direct target of miR-508-5p, and rescuing S100A16 expression could reverse the effect of miR-508-5p mimics on A549 cell proliferation and metastasis. miR-508-5p could involve the coordination of AKT signaling and epithelial-mesenchymal transition (EMT) progress using western-blot assays and rescuing S100A16 expression could reverse the inhibited AKT signaling and EMT progress induced by miR-508-5p mimics.

CONCLUSIONS

We found that miR-508-5p targeted S100A16 to regulate AKT signaling and EMT progress in A549 cells, resulting in impaired cell proliferation and metastasis activity, suggesting that miR-508-5p might be a promising therapeutic target and an important diagnostic and prognostic marker for improved LUAC therapeutic schedule.

RAGE Inhibitors for Targeted Therapy of Cancer: A Comprehensive Review

The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin family that is overexpressed in several cancers. RAGE is highly expressed in the lung, and its expression increases proportionally at the site of inflammation. This receptor can bind a variety of ligands, including advanced glycation end products, high mobility group box 1, S100 proteins, adhesion molecules, complement components, advanced lipoxidation end products, lipopolysaccharides, and other molecules that mediate cellular responses related to acute and chronic inflammation. RAGE serves as an important node for the initiation and stimulation of cell stress and growth signaling mechanisms that promote carcinogenesis, tumor propagation, and metastatic potential. In this review, we discuss different aspects of RAGE and its prominent ligands implicated in cancer pathogenesis and describe current findings that provide insights into the significant role played by RAGE in cancer. Cancer development can be hindered by inhibiting the interaction of RAGE with its ligands, and this could provide an effective strategy for cancer treatment.

An inhibitor of BRD4, GNE987, inhibits the growth of glioblastoma cells by targeting C-Myc and S100A16

PURPOSE

Among children, glioblastomas (GBMs) are a relatively common type of brain tumor. BRD4 expression was elevated in GBM and negatively correlated with the prognosis of glioma. We investigated the anti-GBM effects of a novel BRD4 inhibitor GNE987.

METHODS

We evaluated the anti-tumor effect of GNE987 in vitro and in vivo by Western blot, CCK8, flow cytometry detection, clone formation, the size of xenografts, and Ki67 immunohistochemical staining, and combined ChIP-seq with RNA-seq techniques to find its anti-tumor mechanism.

RESULTS

In vitro experiments showed that GNE987 significantly degraded BRD4, inhibited the proliferation of GBM cells, blocked the cell cycle, and induced apoptosis. Similarly, in vivo experiments, GNE987 also inhibited GBM growth as seen from the size of xenografts and Ki67 immunohistochemical staining. Based on Western blotting, GNE987 can significantly reduce the protein level of C-Myc; meanwhile, we combined ChIP-seq with RNA-seq techniques to confirm that GNE987 downregulated the transcription of S100A16 by disturbing H3K27Ac. Furthermore, we validated that S100A16 is indispensable in GBM growth.

CONCLUSION

GNE987 may be effective against GBM that targets C-Myc expression and influences S100A16 transcription through downregulation of BRD4.

A bioinformatics-based immune-related prognostic index for lung adenocarcinoma that predicts patient response to immunotherapy and common treatments

Background

There is increasing evidence of the effectiveness of immune checkpoint blockade (ICB) therapy for the treatment of lung adenocarcinoma (LUAD). However, the benefits of ICB therapy vary among LUAD patients. Due to the research dimension, existing biomarkers, such as programmed death-ligand 1 (PD-L1) expression and tumor mutation burden (TMB), could not reflect the complex tumor environment, and had low prediction accuracy of ICB. Therefore, we aimed to uncover a prognostic biomarker that could also predict whether a patient would benefit from ICB therapy and other common treatments from multiple dimensions, so as to improve the prediction accuracy of pre-treatment patients.

Methods

Based on the LUAD dataset retrieved from The Cancer Genome Atlas (TCGA) database, 50 immune-related hub genes were identified using weighted gene co-expression network analysis and univariate Cox regression analyses. An immune-related gene prognostic index (IRGPI) was constructed using a Cox proportional-hazards model based on 15 genes and validated using GSE72094 dataset. We tested its prognostic accuracy by Kaplan-Meier (K-M) survival curves of the two datasets and assessed its predictive power by comparing area under curve (AUC) of IRGPI with existing biomarkers. Subsequently, we analyzed the molecular and immune characteristics, and evaluated the benefits of ICB by PD-L1 expression and Tumor Immune Dysfunction and Exclusion (TIDE) analysis, predicted the inhibitory concentration 50 of common treatments drugs for two IRGPI score-related subgroups.

Results

Patients in the IRGPI-high subgroup had lower overall survival (OS) than patients in the IRGPI-low subgroup in K-M survival curve in two cohorts. And IRGPI has AUC values of 0.715, 0.724, and 0.743 in 1, 2, and 3 years, respectively. A higher tumor mutation burden and PD-L1 expression and the tumor microenvironment (TME) landscape demonstrated that IRGPI-high subgroup patients may respond better to ICB therapy. Genomics of Drug Sensitivity in Cancer (GDSC) analysis indicated that the IRGPI-high subgroup showed greater sensitivity to chemotherapy.

Conclusions

IRGPI is a prospective biomarker for evaluating whether a patient will benefit from ICB therapy and other treatments, and distinguishing patients with different molecular and immune characteristics.

A Novel Immune-Related Prognostic Signature Predicting Survival in Patients with Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma (PAAD) carries the lowest survival rate of all major organ cancers, which is of dismal prognosis and high mortality rate. Thus, the present study attempted to identify a few novel prognostic biomarkers and establish an immune-related prognostic signature which could predict the prognosis of PAAD. Four prognostic immune-related genes (IRGs) including S100A6, S100A10, S100A16, and SDC1 were screened by differentially expressed gene (DEG) identification and weighted gene coexpression network analysis (WGCNA). Subsequent analysis proved the high expression of these IRGs in PAAD tissues, suggested by TCGA-PAAD data, merged microarray-acquired dataset (MMD), GEPIA, and Oncomine webtool. By using MMD and TCGA-PAAD data, S100A6 (MMD: AUC = 0.897; TCGA: AUC = 0.843), S100A10 (MMD: AUC = 0.880; TCGA: AUC = 0.780), S100A16 (MMD: AUC = 0.878; TCGA: AUC = 0.838), and SDC1 (MMD: AUC = 0.885; TCGA: AUC = 0.812) exhibited excellent diagnostic efficiency for PAAD. By conducting connectivity map (CMap) analysis, we concluded that three molecule drugs (sulpiride, famotidine, and nalidixic acid) might have worked in the treatment of PAAD. Then, an immune-related prognostic index was constructed, which was validated as an independent prognostic factor for PAAD patients (P=0.004). We further constructed a nomogram by using this immune-related signature and age, the prognostic value of which was validated by using concordance index (C-index = 0.780) and area under curve (AUC = 0.909). Moreover, the immune-related prognostic signature was associated with response to anti-PD-1/L1 immunotherapy. To sum up, four IRGs were screened out and verified to be novel immune-related prognostic biomarkers in PAAD. Besides, sulpiride, famotidine, and nalidixic acid might be potential choices in the treatment of PAAD. An immune-related signature was established to show great potential for prognosis prediction for PAAD, independently, which might guide more effective immunotherapy strategies. A nomogram is further established by using this immune-related prognostic index, which might contribute to more effective prognosis prediction in PAAD patients.

S100A16 induces epithelial-mesenchymal transition in human PDAC cells and is a new therapeutic target for pancreatic cancer treatment that synergizes with gemcitabine

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, with a poor 5-year survival rate of approximately 6%, mostly due to poor treatment response and early progression. The S100 gene family participates in various pathophysiological processes in various malignancies. S100A16 is a member of the S100 family, which is abnormally expressed in PDAC; however, its biological functions and mechanisms of action remain unclear. We analysed the Gene Expression Omnibus (GEO) public database and the gene ChIP data collected in our previous study of human PDAC cell line PANC-1 cocultured with M2 macrophages to identify differentially expressed genes (DEGs). Twenty-three overexpressed genes were identified by screening. Then, the selected genes were analysed using The Cancer Genome Atlas (TCGA) database to assess whether they have significant impact on the overall survival (OS) of PDAC patients. Of the 14 DEGs identified, S100A16 was associated with poor prognosis and was selected for further investigation; the results indicate that S100A16 is positively correlated with epithelial-mesenchymal transition (EMT)-related genes in the TCGA dataset. Subsequent in vitro and in vivo experiments demonstrated that S100A16 induces the EMT to promote the metastasis of human PDAC cells and that the effect is mediated by the enhanced expression of TWIST1 and activation of the STAT3 signalling pathway. The antitumour effect of gemcitabine (GEM) was enhanced in combination with S100A16 downregulation. In conclusion, our findings suggest that S100A16 is a novel potential therapeutic target for human PDAC treatment.

S100A16 suppresses the proliferation, migration and invasion of colorectal cancer cells in part via the JNK/p38 MAPK pathway

S100 calcium binding protein A16 (S100A16) is the most recent member of the S100 calcium-binding protein family. The function of S100A16 has been associated with various types of cancer; however, its role in colorectal cancer (CRC) remains unknown. Therefore, the aim of the present study was to investigate the role of S100A16 in CRC progression. The Oncomine dataset used in the current study revealed that the expression of S100A16 was decreased in CRC compared with normal colorectal tissues. Similar results were also determined via immunohistochemistry. In addition, a negative association was identified between S100A16 expression and the prognosis of patients with CRC. Further functional experiments revealed that S100A16 knockdown promoted the proliferation, migration and invasion of HCT116 and SW480 cells, and vice versa in Lovo cells. Epithelial-mesenchymal transition (EMT) was promoted and the JNK/p38 MAPK pathway was activated in HCT116 cells following S100A16 knockdown, as determined via western blotting. Furthermore, S100A16 silencing promoted the migration and invasion of cells. EMT was also reversed when cells were treated with the JNK inhibitor (SP600125) or the p38 inhibitor (SB203580). In summary, the results of the present study demonstrated that S100A16 suppressed the proliferation, migration and invasion of CRC cells partially via the JNK/p38 MAPK signalling pathway and subsequent EMT mediation.

Identification of Prognostic Immune-Related Genes by Integrating mRNA Expression and Methylation in Lung Adenocarcinoma

Background

There is plenty of evidence showing that immune-related genes (IRGs) and epigenetic modifications play important roles in the biological process of cancer. The purpose of this study is to establish novel IRG prognostic markers by integrating mRNA expression and methylation in lung adenocarcinoma (LUAD).

Methods and Results

The transcriptome profiling data and the RNA-seq data of LUAD with the corresponding clinical information of 543 LUAD cases were downloaded from The Cancer Genome Atlas (TCGA) database, which were analyzed by univariate Cox proportional regression and multivariate Cox proportional regression to develop an independent prognostic signature. On the basis of this signature, we could divide LUAD patients into the high-risk, medium-risk, and low-risk groups. Further survival analyses demonstrated that high-risk patients had significantly shorter overall survival (OS) than low-risk patients. The signature, which contains 8 IRGs (S100A16, FGF2, IGKV4-1, CX3CR1, INHA, ANGPTL4, TNFRSF11A, and VIPR1), was also validated by data from the Gene Expression Omnibus (GEO) database. We also conducted analyses of methylation levels of the relevant IRGs and their CpG sites. Meanwhile, their associations with prognosis were examined and validated by the GEO database, revealing that the methylation levels of INHA, S100A16, the CpG site cg23851011, and the CpG site cg06552037 may be used as the potential regulators for the treatment of LUAD.

Conclusion

Collectively, INHA, S100A16, the CpG site cg23851011, and the CpG site cg06552037 are promising biomarkers for monitoring the outcomes of LUAD.

Clinicopathological and prognostic significance of nuclear UGDH localization in lung adenocarcinoma

This study aimed to clarify relationships among UDP-glucose-6 dehydrogenase (UGDH) expression, clinicopathological factors, and the prognosis of patients, and to determine the role of UGDH in lung adenocarcinoma (AC). Firstly, UGDH expression and localization in 126 lung AC tissues were immunohistochemically studied, and associations with clinicopathological parameters and patients' prognosis were evaluated. Secondly, serum UGDH levels were measured in 267 lung cancer patients and 100 healthy controls. Finally, the effects of UGDH knockdown by siRNA on migration and invasion abilities were analyzed. As a result, nuclear UGDH staining was significantly correlated with poorer differentiation, a larger tumor size, higher p-TNM stage, positive nodal metastasis, positive lymphatic invasion, and positive vascular invasion in lung AC patients. Nuclear UGDH-positive patients showed significantly poorer survival than nuclear UGDH-negative patients. Serum UGDH levels were especially higher in lung AC patients even in stage I than those in healthy controls. In lung AC cell lines, nuclear expression levels of UGDH were higher in LC-2/ad cells than in A549 cells. UGDH siRNA-treated LC-2/ad cells showed significantly decreased migration and invasion abilities, but no significant differences were observed in UGDH siRNA-treated A549 cells. These data indicate that UGDH expression and localization are an early sero-diagnostic marker in addition to a poor prognostic indicator in lung AC patients.