PRSS23 knockdown inhibits gastric tumorigenesis through EIF2 signaling

PRSS23-eIF4E-c-Myc axis promotes gastric tumorigenesis and progression

Gastric cancer is one of the most common malignant tumors. Our previous study showed that PRSS23 expression is increased in human gastric cancer tissues and PRSS23 knockdown inhibits gastric cancer cell growth. This current study aims to uncover the mechanism underlying PRSS23's involvement in gastric tumorigenesis and progression. We established that PRSS23 influences gastric cancer growth both in vitro and in vivo by modulating the eIF4E-c-Myc axis (eIF4E, p-eIF4E, 4EBP1, p-4EBP1, and c-Myc). Our investigation revealed that PRSS23 interacts with eIF4E via its trypsin domain, while eIF4E binds to PRSS23 through the amino acid residue S209, as confirmed by co-IP and immunofluorescence assays. Multiplexed immunofluorescence assay demonstrated a significant elevation of PRSS23 and p-4EBP1 levels in 232 paired gastric cancer tissues. Moreover, in 49 patients exhibiting relatively high PRSS23 expression, the levels of eIF4E-c-Myc axis-related proteins were increased. Importantly, higher PRSS23 expression correlated significantly with increased lymph node metastasis and advanced clinical staging, leading to poorer patient prognosis. These results highlight the role of upregulated PRSS23 in promoting gastric tumorigenesis and progression by activating the eIF4E-c-Myc axis, underscoring the PRSS23-eIF4E-c-Myc axis as a promising therapeutic target for gastric cancer.

Biomass Smoke Exposure Reduces DNA Methylation Levels in PRSS23 (cg23771366) in Women with Chronic Obstructive Pulmonary Disease

COPD induced by biomass-burning smoke is a public health problem in developing countries. Biomass-based fuels are ineffective and deliver elevated levels of carbon monoxide, polycyclic aromatic hydrocarbons, and fine particulate matter. PRSS23 participates in extracellular matrix remodeling processes in COPD patients. Our objective was to estimate the DNA methylation levels of cg23771366 (PRSS23) and their clinical relevance in COPD caused by chronic exposure to biomass-burning smoke (BBS). We included 80 women with COPD (COPD-BBS) (≥200 h per year), 180 women with exposure to BBS (≥200 h per year) but without COPD (BBES), and 79 lung-healthy women (HW) without exposure to biomass-burning smoke. The DNA methylation analysis shows significant differences between the three groups included in this study (p < 0.001). HW had high methylation levels (100%) in cg23771366 (PRSS23). In comparison, COPD-BBS and BBES had low levels [0.91% vs. 9.17%, respectively], showing statistically significant differences (p = 0.011) between both groups, with the COPD-BBS presenting the lowest levels in the methylation of cg23771366. In conclusion, chronic biomass-burning smoke exposure is associated with decreased levels of DNA methylation at the CpG cg23771366 site in PRSS23, reinforcing the relationship between PRSS23 and particulate matter.

Targeting SIGLEC15 as an emerging immunotherapy for anaplastic thyroid cancer

Anaplastic thyroid carcinoma (ATC) is the most aggressive subtype of thyroid cancer with few effective therapies. Though immunotherapies such as targeting PD-1/PD-L1 axis have benefited patients with solid tumor, the druggable immune checkpoints are quite limited in ATC. In our study, we focused on the anti-tumor potential of sialic acid-binding Ig-like lectins (Siglecs) in ATC. Through screening by integrating microarray datasets including 216 thyroid-cancer tissues and single-cell RNA-sequencing, SIGLEC family members CD33, SIGLEC1, SIGLEC10 and SIGLEC15 were significantly overexpressed in ATC, among which SIGLEC15 increased highest and mainly expressed on cancer cells. SIGLEC15high ATC cells are characterized by high expression of serine protease PRSS23 and cancer stem cell marker CD44. Compared with SIGLEC15low cancer cells, SIGLEC15high ATC cells exhibited higher interaction frequency with tumor microenvironment cells. Further study showed that SIGLEC15high cancer cells mainly interacted with T cells by immunosuppressive signals such as MIF-TNFRSF14 and CXCL12-CXCR4. Notably, treatment of anti-SIGLEC15 antibody profoundly increased the cytotoxic ability of CD8+ T cells in a co-culture model and zebrafish-derived ATC xenografts. Consistently, administration of anti-SIGLEC15 antibody significantly inhibited tumor growth and prolonged mouse survival in an immunocompetent model of murine ATC, which was associated with increase of M1/M2, natural killer (NK) cells and CD8+ T cells, and decrease of myeloid-derived suppressor cells (MDSCs). SIGLEC15 inhibited T cell activation by reducing NFAT1, NFAT2, and NF-κB signals. Blocking SIGLEC15 increased the secretion of IFN-γ and IL-2 in vitro and in vivo. In conclusion, our finding demonstrates that SIGLEC15 is an emerging and promising target for immunotherapy in ATC.

Targeting PRSS23 with tipranavir induces gastric cancer stem cell apoptosis and inhibits growth of gastric cancer via the MKK3/p38 MAPK-IL24 pathway

Gastric cancer stem cells (GCSCs) contribute to the refractory features of gastric cancer (GC) and are responsible for metastasis, relapse, and drug resistance. The key factors drive GCSC function and affect the clinical outcome of GC patients remain poorly understood. PRSS23 is a novel serine protease that is significantly up-regulated in several types of cancers and cancer stem cells, and related to tumor progression and drug resistance. In this study, we investigated the role of PRSS23 in GCSCs as well as the mechanism by which PRSS23 regulated the GCSC functions. We demonstrated that PRSS23 was critical for sustaining GCSC survival. By screening a collection of human immunodeficiency virus (HIV) protease inhibitors (PIs), we identified tipranavir as a PRSS23-targeting drug, which effectively killed both GCSC and GC cell lines (its IC50 values were 4.7 and 6.4 μM in GCSC1 cells and GCSC2 cells, respectively). Administration of tipranavir (25 mg·kg-1·d-1, i.p., for 8 days) in GCSC-derived xenograft mice markedly inhibited the growth of subcutaneous GCSC tumors without apparent toxicity. In contrast, combined treatment with 5-FU plus cisplatin did not affect the tumor growth but causing significant weight loss. Furthermore, we revealed that tipranavir induced GCSC cell apoptosis by suppressing PRSS23 expression, releasing MKK3 from the PRSS23/MKK3 complex to activate p38 MAPK, and thereby activating the IL24-mediated Bax/Bak mitochondrial apoptotic pathway. In addition, tipranavir was found to kill other types of cancer cell lines and drug-resistant cell lines. Collectively, this study demonstrates that by targeting both GCSCs and GC cells, tipranavir is a promising anti-cancer drug, and the clinical development of tipranavir or other drugs specifically targeting the PRSS23/MKK3/p38MAPK-IL24 mitochondrial apoptotic pathway may offer an effective approach to combat gastric and other cancers.

Dissecting the epigenomic differences between smoking and nicotine dependence in a veteran cohort

Smoking is a serious public health issue linked to more than 8 million deaths per year worldwide and may lead to nicotine dependence (ND). Although the epigenomic literature on smoking is well established, studies evaluating the role of epigenetics in ND are limited. In this study, we examined the epigenomic signatures of ND and how these differ from smoking exposure to identify biomarkers specific to ND. We investigated the peripheral epigenetic profile of smoking status (SS) and ND in a US male veteran cohort. DNA from saliva was collected from 1135 European American (EA) male US military veterans. DNAm was assessed using the Illumina Infinium Human MethylationEPIC BeadChip array. SS was evaluated as current smokers (n = 137; 12.1%) and non-current smokers (never and former; n = 998; 87.9%). NDFTND was assessed as a continuous variable using the Fagerström Test for ND (FTND; n = 1135; mean = 2.54 ± 2.29). Epigenome-wide association studies (EWAS) and co-methylation analyses were conducted for SS and NDFTND . A total of 450 and 22 genome-wide significant differentially methylated sites (DMS) were associated with SS and NDFTND , respectively (15 overlapped DMS). We identified 97 DMS (43 genes) in SS-EWAS previously reported in the literature, including AHRR and F2RL3 genes (p-value: 1.95 × 10-83 to 4.55 × 10-33 ). NDFTND novel DMS mapped to NEUROG1, ANPEP, and SLC29A1. Co-methylation analysis identified 386 modules (11 SS-related and 19 NDFTND -related). SS-related modules showed enrichment for alcoholism, while NDFTND -related modules were enriched for nicotine addiction. This study confirms previous findings associated with SS and identifies novel and-potentially specific-epigenetic biomarkers of ND that may inform prognosis and novel treatment strategies.

Serine protease PRSS23 drives gastric cancer by enhancing tumor associated macrophage infiltration via FGF2

Serine proteases has been considered to be closely associated with the inflammatory response and tumor progression. As a novel serine protease, the biological function of PRSS23 is rarely studied in cancers. In this study, the prognostic significance of PRSS23 was analyzed in two-independent gastric cancer (GC) cohorts. PRSS23 overexpression was clinically correlated with poor prognosis and macrophage infiltration of GC patients. Loss-of-function study verified that PRSS23 plays oncogenic role in GC. RNA-seq, qRT-PCR, western blotting and ELISA assay confirmed that serine protease PRSS23 positively regulated FGF2 expression and secretion. Single-cell analysis and gene expression correlation analysis showed that PRSS23 and FGF2 were high expressed in fibroblasts, and highly co-expressed with the biomarkers of tumor associated macrophages (TAMs), cancer-associated fibroblasts (CAFs) and mesenchymal cells. Functional analysis confirmed PRSS23/FGF2 was required for TAM infiltration. Rescue assay further verified that PRSS23 promotes GC progression and TAM infiltration through FGF2. Survival analysis showed that high infiltration of M1-macrophage predicted favorable prognosis, while high infiltration level of M2-macrophage predicted poor prognosis in GC. Our finding highlights that PRSS23 promotes TAM infiltration through regulating FGF2 expression and secretion, thereby resulting in a poor prognosis.

2-(2-phenylethyl)chromone-enriched extract of the resinous heartwood of Chinese agarwood (Aquilaria sinensis) protects against taurocholic acid-induced gastric epithelial cells apoptosis through Perk/eIF2α/CHOP pathway

BACKGROUND

Injury of gastric epithelial cells is one of the most important pathological features of bile reflux gastritis. Chinese agarwood (the resinous heartwood of Aquilaria sinensis) has been used to treat stomach problems for thousands of years in China. However, the pathological mechanism of epithelial cells death induced by bile acids and the therapeutic target of Chinese agarwood for improving bile reflux gastritis have not yet been fully clarified.

PURPOSE

This study aimed to investigate the pro-apoptotic effect of taurocholic acid (TCA) by regulating the ER stress pathway. Moreover, the role of Chinese agarwood 2-(2-phenylethyl)chromone-enriched extract (CPE) to inhibit gastric epithelial cell death induced by TCA was also been demonstrated.

METHODS

We adopted human gastric epithelial GES-1 cells to explore the mechanism of TCA-induced cell death in vitro. Then the cell viability, apoptosis rate, and protein expressions were evaluated to explore the protective effects of CPE on GES-1 cells by TCA injury. The therapeutic effect of CPE on bile reflux gastritis was further confirmed by the bile reflux mice in vivo.

RESULTS

Our results demonstrated that TCA activated GES-1 cell apoptosis by increased cleavage of caspase-7 and PARP. Further experiments showed that TCA up-regulated endoplasmic reticulum (ER) stress, subsequently triggered the apoptosis of the epithelial cells. Our research explored that CPE is the main effective fraction in Chinese agarwood by preventing the TCA-induced gastric epithelial cell injury. CPE effectively suppressed GES-1 cell apoptosis activated by TCA through inhibiting Perk/eIF2α/CHOP pathway. The anti-apoptotic effect of CPE on gastric mucosa had also been confirmed in vivo. Moreover, the main effective components in CPE corresponding to the protection of epithelial cells were also been identified.

CONCLUSION

Our finding suggested that CPE recovered the TCA-induced epithelial cell apoptosis by mediating the activation of ER stress, which explored potential medicine to treat bile reflux gastritis.

Multi-time scale transcriptomic analysis on the dynamic process of tamoxifen resistance development in breast cancer cell lines

BACKGROUND

Approximately 30% of breast cancer patients develop endocrine resistance after tamoxifen therapy. There still lacks a comprehensive understanding on the mechanism of tamoxifen resistance. This study aims to explore the dynamic process of ER + breast cancer resistance to tamoxifen through the time course transcriptomic analysis.

METHODS

The transcriptome profiles of human breast cancer cell line MCF-7 treated with tamoxifen at different time scales were collected from LINCS, SRA and GEO databases. Differentially expressed genes (DEGs) were identified in the short-term tamoxifen treatment and tamoxifen-resistant cell lines. The time course analysis was used to explore the dynamic development of tamoxifen resistance using the transcriptome profiles of tamoxifen-cultured MCF-7 for 1-12 weeks.

RESULTS

After the short-term treatment of MCF-7 with tamoxifen for 6 h or 24 h, the expression level of gene PRSS23 was significantly reduced. However, its expression recovered in the resistant cell lines. The time course analysis identified 9 clusters of the DEGs based on the temporal trend of their expression levels. Gene PRSS23 belongs to cluster 2 in which the expression levels were significantly down-regulated in the first 4 weeks but gradually recovered afterwards. Functional enrichment analysis of the DEGs in cluster 2 showed that they are significantly enriched in DNA replication, mismatch repair and cell cycle pathways. Their specific role in the resistance development needs to be further explored. The protein-protein interaction network analysis indicates that gene PRSS23 participates in the drug resistance by regulating multiple tamoxifen drug targets.

CONCLUSIONS

The acquired drug resistance in ER + breast cancer is a complex and dynamic biological process. PRSS23 plays an important role in the development of resistance and is a potential target for overcoming resistance.

Meta-analysis of whole-genome gene expression datasets assessing the effects of IDH1 and IDH2 mutations in isogenic disease models

Mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 are oncogenic drivers to a variable extent in several tumors, including gliomas, acute myeloid leukemia (AML), cholangiocarcinoma, melanoma, and thyroid carcinoma. The pathobiological effects of these mutations vary considerably, impeding the identification of common expression profiles. We performed an expression meta-analysis between IDH-mutant (IDH^mut) and IDH-wild-type (IDH^wt) conditions in six human and mouse isogenic disease models. The datasets included colon cancer cells, glioma cells, heart tissue, hepatoblasts, and neural stem cells. Among differentially expressed genes (DEGs), serine protease 23 (PRSS23) was upregulated in four datasets, i.e., in human colon carcinoma cells, mouse heart tissue, mouse neural stem cells, and human glioma cells. Carbonic anhydrase 2 (CA2) and prolyl 3-hydroxylase 2 (P3H2) were upregulated in three datasets, and SOX2 overlapping transcript (SOX2-OT) was downregulated in three datasets. The most significantly overrepresented protein class was termed intercellular signal molecules. An additional DEG set contained genes that were both up- and downregulated in different datasets and included oxidases and extracellular matrix structural proteins as the most significantly overrepresented protein classes. In conclusion, this meta-analysis provides a comprehensive overview of the expression effects of IDH mutations shared between different isogenic disease models. The generated dataset includes biomarkers, e.g., PRSS23 that may gain relevance for further research or clinical applications in IDH^mut tumors.

Shared Gene Expression and Immune Pathway Changes Associated with Progression from Nevi to Melanoma

Simple Summary

Melanoma is a deadly skin cancer, and the incidence of melanoma is rising. Chemoprevention, using small molecule drugs to prevent the development of cancer, is a key strategy that could reduce the burden of melanoma on society. The long-term goal of our study is to develop a gene signature biomarker of progression from nevi to melanoma. We found that a small number of genes can distinguish nevi from melanoma and identified shared genes and immune-related pathways that are associated with progression from nevi to melanoma across independent datasets. This study demonstrates (1) a novel approach to aid melanoma chemoprevention trials by using a gene signature as a surrogate endpoint and (2) the feasibility of determining a gene signature biomarker of melanoma progression.

Abstract

There is a need to identify molecular biomarkers of melanoma progression to assist the development of chemoprevention strategies to lower melanoma incidence. Using datasets containing gene expression for dysplastic nevi and melanoma or melanoma arising in a nevus, we performed differential gene expression analysis and regularized regression models to identify genes and pathways that were associated with progression from nevi to melanoma. A small number of genes distinguished nevi from melanoma. Differential expression of seven genes was identified between nevi and melanoma in three independent datasets. C1QB, CXCL9, CXCL10, DFNA5 (GSDME), FCGR1B, and PRAME were increased in melanoma, and SCGB1D2 was decreased in melanoma, compared to dysplastic nevi or nevi that progressed to melanoma. Further supporting an association with melanomagenesis, these genes demonstrated a linear change in expression from benign nevi to dysplastic nevi to radial growth phase melanoma to vertical growth phase melanoma. The genes associated with melanoma progression showed significant enrichment of multiple pathways related to the immune system. This study demonstrates (1) a novel application of bioinformatic approaches to aid clinical trials of melanoma chemoprevention and (2) the feasibility of determining a gene signature biomarker of melanomagenesis.

Inhibition of YTHDF2 triggers proteotoxic cell death in MYC-driven breast cancer

RNA-binding proteins (RBPs) are critical regulators of post-transcriptional gene expression, and aberrant RBP-RNA interactions can promote cancer progression. Here, we interrogate the function of RBPs in cancer using pooled CRISPR-Cas9 screening and identify 57 RBP candidates with distinct roles in supporting MYC-driven oncogenic pathways. We find that disrupting YTHDF2-dependent mRNA degradation triggers apoptosis in triple-negative breast cancer (TNBC) cells and tumors. eCLIP and m6A sequencing reveal that YTHDF2 interacts with mRNAs encoding proteins in the MAPK pathway that, when stabilized, induce epithelial-to-mesenchymal transition and increase global translation rates. scRibo-STAMP profiling of translating mRNAs reveals unique alterations in the translatome of single cells within YTHDF2-depleted solid tumors, which selectively contribute to endoplasmic reticulum stress-induced apoptosis in TNBC cells. Thus, our work highlights the therapeutic potential of RBPs by uncovering a critical role for YTHDF2 in counteracting the global increase of mRNA synthesis in MYC-driven breast cancers.

Perturbation of Specific Signaling Pathways Is Involved in Initiation of Mouse Liver Fibrosis

BACKGROUND AND AIMS

To identify the regulatory role of protein phosphatase 2A (PP2A) in the development of liver disease, we generated a mouse model with hepatocyte-specific deletion of Ppp2r1a gene (encoding PP2A Aα subunit).

APPROACH AND RESULTS

Homozygote (HO) mice and matched wild-type littermates were investigated at 3, 6, 9, 12, 15, and 18 months of age. Pathological examination showed that PP2A Aα deficiency in hepatocytes resulted in progressive liver fibrosis phenotype from 9 months of age. No hepatocyte death was observed in HO mice. However, perturbation of pathways including epidermal growth factor receptor 1 (EGFR1), amino acid metabolism, and translation factors as well as leptin and adiponectin led to pronounced hepatic fibrosis. In vitro studies demonstrated the involvement of specific B subunit complexes in the regulation of EGFR1 signaling pathway and cross talk between defected hepatocytes and stimulation of interstitial hyperplasia. It is noteworthy that HO mice failed to develop hepatocellular carcinoma for as long as 22 months of age. We further demonstrate that PP2A Aβ-containing holoenzymes played a critical role in preventing hepatocyte apoptosis and antagonizing tumorigenesis through specific pathways on Aα loss. Furthermore, PP2A Aα and Aβ were functionally distinct, and the Aβ isoform failed to substitute for Aα in the development of inflammation and liver fibrosis.

CONCLUSIONS

These observations identify pathways that contribute to the pathogenesis of liver fibrosis and provide putative therapeutic targets for its treatment.

Identification of Overexpressed Genes in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene-expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients' overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E-selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small-molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer-driving role of the targets herewith identified.

Molecular targeted treatment and drug delivery system for gastric cancer

Gastric cancer is still a major cancer worldwide. The early diagnosis rate of gastric cancer in most high incidence countries is low. At present, the overall treatment effect of gastric cancer is poor, and the median overall survival remains low. Most of the patients with gastric cancer are in an advanced stage when diagnosed, and drug treatment has become the main means. Thus, new targeted drugs and therapeutic strategies are the hope of improving the therapeutic effect of gastric cancer. In this review, we summarize the new methods and advances of targeted therapy for gastric cancer, including novel molecular targeted therapeutic agents and drug delivery systems, with a major focus on the development of drug delivery systems (drug carriers and targeting peptides). Elaborating these new methods and advances will contribute to the management of gastric cancer.

Comprehensive Analysis of Key Genes and Regulatory Elements in Osteosarcoma Affected by Bone Matrix Mineral With Prognostic Values

Osteosarcoma is one of the most common types of bone sarcoma with a poor prognosis. However, genes involved in the mineral metabolism in the microenvironment of the bone affected by osteosarcoma are, to date, largely unknown. A public data series (GSE114237) was used to identify differentially expressed genes (DEGs) between osteosarcoma cells adhering to demineralized osseous surfaces and mineralized osseous surfaces. Functional enrichment analysis of DEGs and hub genes, protein-protein interaction network of DEGs and regulatory network (miRNA-mRNA network and transcription factor (TF)-mRNA network), survival analysis of hub genes was visualized. The prognostic hub genes were considered as candidate genes and their functional predictions were analyzed. A total of 207 DEGs were mainly enriched in extracellular space and thirteen hub genes were mainly enriched in the function of epithelial to mesenchymal transition. However, out of these, only one candidate gene was found to be suitable as a candidate gene. Besides that, 297 miRNAs and 349 TFs interacting with the hub genes were screened. In conclusion, the DEGs, hub genes, miRNAs and TFs screened out in this research could contribute to comprehend the latent mechanisms in osteosarcoma affected by matrix mineral and provide potential research molecular for further study.