Epigenetic silencing of PRSS3 provides growth and metastasis advantage for human hepatocellular carcinoma

Shear Stress Drives the Cleavage Activation of Protease-Activated Receptor 2 by PRSS3/Mesotrypsin to Promote Invasion and Metastasis of Circulating Lung Cancer Cells

When circulating tumor cells (CTCs) travel in circulation, they can be killed by detachment-induced anoikis and fluidic shear stress (SS)-mediated apoptosis. Circulatory treatment, which can make CTCs detached but also generate SS, can increase metastasis of cancer cells. To identify SS-specific mechanosensors without detachment impacts, a microfluidic circulatory system is used to generate arteriosus SS and compare transcriptome profiles of circulating lung cancer cells with suspended cells. Half of the cancer cells can survive SS damage and show higher invasion ability. Mesotrypsin (PRSS3), protease-activated receptor 2 (PAR2), and the subunit of activating protein 1, Fos-related antigen 1 (FOSL1), are upregulated by SS, and their high expression is responsible for promoting invasion and metastasis. SS triggers PRSS3 to cleave the N-terminal inhibitory domain of PAR2 within 2 h. As a G protein-coupled receptor, PAR2 further activates the Gαi protein to turn on the Src-ERK/p38/JNK-FRA1/cJUN axis to promote the expression of epithelial-mesenchymal transition markers, and also PRSS3, which facilitates metastasis. Enriched PRSS3, PAR2, and FOSL1 in human tumor samples and their correlations with worse outcomes reveal their clinical significance. PAR2 may serve as an SS-specific mechanosensor cleavable by PRSS3 in circulation, which provides new insights for targeting metastasis-initiating CTCs.

Serine Protease 3 Promotes Progression of Diffuse Large B-Cell Lymphoma and Serves as a Novel Prognostic Predictor

Diffuse large B-cell lymphoma (DLBCL) ranks among the most prevalent malignancies of the lymphohematopoietic system in adults. The PRSS (Serine Protease) protein family members had been reported to be involved in carcinogenesis as well as tumor progression. Here, we aimed to explore the expression profile of PRSS3 in DLBCL and investigate its clinical significance as well as detailed functions. We retrospectively enrolled 155 DLBCL patients from our hospital and tested protein expression level of PRSS3 through immunohistochemical staining. Accordingly, PRSS3 was highly expressed in certain DLBCL tissues. Chi-square test revealed that higher PRSS3 expression was correlated with advanced Ann Arbor stage, elevated serum LDH level, and higher International Prognostic Index. Moreover, univariate and multivariate analyses confirmed that higher PRSS3 can act as an independent unfavorable prognostic predictor for DLBCL. Two human DLBCL cell lines, SUDHL10 and OCI-LY3, were subjected for knockdown assays, followed by phonotype tests including proliferation and invasion. According to the cellular experiments, PRSS3-knockdown resulted in impaired DLBCL proliferation in the two cell lines above. Taken together, PRSS3 is a novel prognostic factor for DLBCL, which functions by multiple signaling pathways.

CpG Site-Specific Methylation-Modulated Divergent Expression of PRSS3 Transcript Variants Facilitates Nongenetic Intratumor Heterogeneity in Human Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most lethal human tumors with extensive intratumor heterogeneity (ITH). Serine protease 3 (PRSS3) is an indispensable member of the trypsin family and has been implicated in the pathogenesis of several malignancies, including HCC. However, the paradoxical effects of PRSS3 on carcinogenesis due to an unclear molecular basis impede the utilization of its biomarker potential. We hereby explored the contribution of PRSS3 transcripts to tumor functional heterogeneity by systematically dissecting the expression of four known splice variants of PRSS3 (PRSS3-SVs, V1~V4) and their functional relevance to HCC.

Methods

The expression and DNA methylation of PRSS3 transcripts and their associated clinical relevance in HCC were analyzed using several publicly available datasets and validated using qPCR-based assays. Functional experiments were performed in gain- and loss-of-function cell models, in which PRSS3 transcript constructs were separately transfected after deleting PRSS3 expression by CRISPR/Cas9 editing.

Results

PRSS3 was aberrantly differentially expressed toward bipolarity from very low (PRSS3Low) to very high (PRSS3High) expression across HCC cell lines and tissues. This was attributable to the disruption of PRSS3-SVs, in which PRSS3-V2 and/or PRSS3-V1 were dominant transcripts leading to PRSS3 expression, whereas PRSS3-V3 and -V4 were rarely or minimally expressed. The expression of PRSS3-V2 or -V1 was inversely associated with site-specific CpG methylation at the PRSS3 promoter region that distinguished HCC cells and tissues phenotypically between hypermethylated low-expression (mPRSS3-SVLow) and hypomethylated high-expression (umPRSS3-SVHigh) groups. PRSS3-SVs displayed distinct functions from oncogenic PRSS3-V2 to tumor-suppressive PRSS3-V1, -V3 or PRSS3-V4 in HCC cells. Clinically, aberrant expression of PRSS3-SVs was translated into divergent relevance in patients with HCC, in which significant epigenetic downregulation of PRSS3-V2 was seen in early HCC and was associated with favorable patient outcome.

Conclusions

These results provide the first evidence for the transcriptional and functional characterization of PRSS3 transcripts in HCC. Aberrant expression of divergent PRSS3-SVs disrupted by site-specific CpG methylation may integrate the effects of oncogenic PRSS3-V2 and tumor-suppressive PRSS3-V1, resulting in the molecular diversity and functional plasticity of PRSS3 in HCC. Dysregulated expression of PRSS3-V2 by site-specific CpG methylation may have potential diagnostic value for patients with early HCC.

High Expression of PRSS3 Indicates Unfavorable Clinical Outcomes in Colon Adenocarcinoma

INTRODUCTION

Serine proteases have been implicated as key drivers and facilitators of cancer malignancy. Protease, serine, 3 (PRSS3), which belongs to the serine proteases family, is reported to be abundantly expressed in a variety of types of tumor and contributes to the initiation and development of cancers. However, the clinical role of PRSS3 in colon adenocarcinoma (CAC) was not clarified yet. In the present study, we explored the potential effect of PRSS3 in CAC and whether it is related to the poor survival of CAC patients.

MATERIALS AND METHODS

The mRNA and protein levels of PRSS3 were examined in CAC samples and connective noncancerous colon samples through quantitative real-time polymerase chain reaction assay and immunohistochemistry staining. Univariate and multivariate analyses were performed to estimate the prognostic role of PRSS3 in enrolled CAC patients.

RESULTS

PRSS3 expression in CAC samples was significantly increased compared with connective noncancerous samples. Moreover, a higher level of PRSS3 was found to be correlated with the larger tumor size, advanced T stage, and positive lymph node metastasis. In addition, PRSS3 was also defined as an unfavorable prognosis factor for CAC patients.

CONCLUSIONS

High expression of PRSS3 was significantly related to the unfavorable clinical features and poor prognosis in CAC patients. It suggested that PRSS3 might serve as a novel prognostic indicator and potential drug target for CAC treatment.

Methylation silencing CDH23 is a poor prognostic marker in diffuse large B-cell lymphoma

Cadherin-23(CDH23) mediates homotypic and heterotypic cell-cell adhesions in cancer cells. However, the epigenetic regulation, the biological functions, the mechanisms and the prognostic value of CDH23 in diffuse large B-cell lymphoma (DLBCL) are still unclear. The Gene Expression Profiling Interactive Analysis (GEPIA) and the Gene Expression Omnibus (GEO) database were employed to analyze the CDH23 expression level in DLBCL. The correlation of CDH23 expression and methylation was analyzed by LinkedOmics database. The prognostic value was analyzed via GEPIA. Correlated genes, target kinase, target miRNA, target transcription factor and biological functions were identified by LinkedOmics and GeneMANIA database. The relationship between CDH23 and the immune cell infiltration was explored by the Tumor Immune Estimation Resource (TIMER). The expression of CDH23 was reduced by DNA methylation significantly in DLBCL tissue. Reduction of CDH23 represented poor outcome of DLBCL patients. Functional enrichment analysis showed that CDH23 mainly enriched in cancer cell growth, cell metastasis, cell adhesion, cell cycle, drug catabolic process, leukocyte mediated immunity and DNA repair by some cancer related kinases, miRNAs and transcription factors. These results indicated that methylated reduction of CDH23 represented poor outcome of DLBCL. CDH23 is associated with essential biological functions and key molecules in DLBCL. CDH23 may play crucial roles in DLBCL tumorigenesis. Our results lay a foundation for further investigation of the role of CDH23 in DLBCL tumorigenesis.

Differential MUC22 expression by epigenetic alterations in human lung squamous cell carcinoma and adenocarcinoma

Disruption in mucins (MUCs) is involved in cancer development and metastasis and is thus used as a biomarker. Non‑small cell lung carcinoma (NSCLC) is characterized by heterogeneous genetic and epigenetic alterations. Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are the two primary subtypes of NSCLC that require different therapeutic interventions. Here, we report distinct expression and epigenetic alterations in mucin 22 (MUC22), a new MUC family member, in LUSC vs. LUAD. In lung cancer cell lines and tissues, MUC22 was downregulated in LUSC (MUC22Low) but upregulated in LUAD (MUC22High) with co‑expression of MUC21. The aberrant expression of MUC22 was inversely correlated with its promoter hypermethylation in LUSC and hypomethylation in LUAD cells and tissues, respectively. Decreased MUC22 expression in NSCLC cell lines was restored upon treatment with epigenetic modifiers 5‑aza‑2'‑deoxycytidine (5‑Aza) or trichostatin A (TSA), accompanied by reduction in global protein level of histone deacetylase 1 (HDAC1) but increased enrichment of histone H3 lysine 9 acetylation (H3K9ac) specifically in the MUC22 promoter in the SK‑MES‑1 cell line. MUC22 knockdown increased the growth and motility of lung cancer cells and an immortalized human bronchial epithelial BEAS‑2B cell line via NF‑κB activation. Clinically, MUC22Low in LUSC and MUC22High in LUAD were shown to be indicators of unfavorable overall survival for patients with early cancer stages. Our study reveals that changes in MUC22 expression due to epigenetic alterations in NSCLC may have important biological significance and prognostic potential in LUSC when compared to LUAD. Thus, MUC22 expression and epigenetic alterations may be used for molecular subtyping of NSCLC in precision medicine.

Hepigenetics: A Review of Epigenetic Modulators and Potential Therapies in Hepatocellular Carcinoma

Hepatocellular carcinoma is the fifth most common cancer worldwide and the second most lethal, following lung cancer. Currently applied therapeutic practices rely on surgical resection, chemotherapy and radiotherapy, or a combination thereof. These treatment options are associated with extreme adversities, and risk/benefit ratios do not always work in patients' favor. Anomalies of the epigenome lie at the epicenter of aberrant molecular mechanisms by which the disease develops and progresses. Modulation of these anomalous events poses a promising prospect for alternative treatment options, with an abundance of felicitous results reported in recent years. Herein, the most recent epigenetic modulators in hepatocellular carcinoma are recapitulated on.

Circular RNA ADAM9 facilitates the malignant behaviours of pancreatic cancer by sponging miR-217 and upregulating PRSS3 expression

Pancreatic cancer (PC) is a highly lethal human cancer. We previously found that Serine protease 3 (PRSS3), as an oncogene, is significantly upregulated in PC. In this study, we aimed to investigate the potential mechanism of PRSS3 dysregulation in PC. In this research, low miR-217 and high circ-ADAM9 expression were found in PC tissues and cell lines, which was closely associated with advanced clinical stage and lymph node metastasis. Patients with low miR-217 or high circ-ADAM9 expression had shorter survival time than those with high miR-217 or low circ-ADAM9 expression. Functionally, manipulation of miR-217 and circ-ADAM9 expression showed opposite effects on cell proliferation, migration and invasion. Stepwise mechanism studies indicated that circ-ADAM9 alleviated the inhibitory effect of miR-217 on PRSS3 by directly sponging miR-217 to increase the expression level of PRSS3, resulting in the activation of ERK/VEGF signalling pathway. In vivo, circ-ADAM9 silencing or miR-217 overexpression evidently retarded the growth of tumour, and the combination of them exhibited an additive inhibitory effect on tumourigenicity. Briefly, the ceRNA regulatory network of circ-ADAM9/miR-217/PRSS3 plays a pivotal role in PC progression by the regulation of ERK/VEGF signalling pathway.

BjussuLAAO-II induces cytotoxicity and alters DNA methylation of cell-cycle genes in monocultured/co-cultured HepG2 cells

Background:

The use of animal venoms and their toxins as material sources for biotechnological applications has received much attention from the pharmaceutical industry. L-amino acid oxidases from snake venoms (SV-LAAOs) have demonstrated innumerous biological effects and pharmacological potential against different cancer types. Hepatocellular carcinoma has increased worldwide, and the aberrant DNA methylation of liver cells is a common mechanism to promote hepatic tumorigenesis. Moreover, tumor microenvironment plays a major role in neoplastic transformation. To elucidate the molecular mechanisms responsible for the cytotoxic effects of SV-LAAO in human cancer cells, this study aimed to evaluate the cytotoxicity and the alterations in DNA methylation profiler in the promoter regions of cell-cycle genes induced by BjussuLAAO-II, an LAAO from Bothrops jaracussu venom, in human hepatocellular carcinoma (HepG2) cells in monoculture and co-culture with endothelial (HUVEC) cells.

Methods:

BjussuLAAO-II concentrations were 0.25, 0.50, 1.00 and 5.00 μg/mL. Cell viability was assessed by MTT assay and DNA methylation of the promoter regions of 22 cell-cycle genes by EpiTect Methyl II PCR array.

Results:

BjussuLAAO-II decreased the cell viability of HepG2 cells in monoculture at all concentrations tested. In co-culture, 1.00 and 5.00 μg/mL induced cytotoxicity (p < 0.05). BjussuLAAO-II increased the methylation of CCND1 and decreased the methylation of CDKN1A in monoculture and GADD45A in both cell-culture models (p < 0.05).

Conclusion:

Data showed BjussuLAAO-II induced cytotoxicity and altered DNA methylation of the promoter regions of cell-cycle genes in HepG2 cells in monoculture and co-culture models. We suggested the analysis of DNA methylation profile of GADD45A as a potential biomarker of the cell cycle effects of BjussuLAAO-II in cancer cells. The tumor microenvironment should be considered to comprise part of biotechnological strategies during the development of snake-toxin-based novel drugs.

Elevated DKK1 expression is an independent unfavorable prognostic indicator of survival in head and neck squamous cell carcinoma

PURPOSE

DKK1 is an antagonist of the Wnt signaling pathway that has various roles in human physiology. Notably, aberrant DKK1 expression is observed in several cancers. In this retrospective study, we assessed the association between DKK1 expression levels and head and neck squamous cell carcinoma (HNSCC) and its prognostic value.

MATERIALS AND METHODS

Using RNA-seq data from HNSCC tumors (N=520) and adjacent normal tissue (N=44) in The Cancer Genome Atlas, we evaluated DKK1 expression levels. Additionally, we evaluated the association of DKK1 expression levels and pathophysiological features of patients with HNSCC and the value of DKK1 expression for prediction of overall survival (OS). We also explored the correlation between DKK1 expression and methylation of its promoter in HNSCC.

RESULTS

DKK1 expression was significantly upregulated in HNSCC compared with normal tissues. Moreover, DKK1 expression was significantly associated with smoking, alcohol abuse, sex, human papillomavirus status, tumor site, tumor invasion, and pathologic stage in HNSCC patients. Kaplan-Meier curves showed that high DKK1 expression was correlated with inferior OS. In addition, univariate and multivariate analyses showed that elevated DKK1 expression was an independent prognostic factor for poor OS (HR: 1.85, 95% CI: 1.31-2.62, P<0.001). Regression analysis identified a strong negative correlation between DKK1 expression and methylation of its promoter.

CONCLUSION

These findings support the hypothesis that elevated DKK1 expression is modulated via methylation of its promoter and indicate that DKK1 expression is a highly informative prognostic biomarker for patients with HNSCC.

Transcription Factor Myeloid Zinc-Finger 1 Suppresses Human Gastric Carcinogenesis by Interacting with Metallothionein 2A

PURPOSE

Metallothionein 2A (MT2A) suppresses the progression of human gastric cancer potentially through an "MT2A-NF-κB pathway" with unclear mechanisms. This study explored the role of a transcription factor, myeloid zinc-finger 1 (MZF1), in MT2A-NF-κB pathway and its clinical significance in gastric cancer.

EXPERIMENTAL DESIGN

MZF1 expression and function in gastric cancer were investigated in vitro and in vivo. The relationship between MZF1 and MT2A was determined by gain-of-function and loss-of-function assays in gastric cancer cells and an immortalized gastric cell line GES-1. The prognostic value of MZF1 expression in association with MT2A was evaluated using IHC in two cohorts.

RESULTS

MZF1 was epigenetically silenced in human gastric cancer cell lines and primary tumors. Overexpression of MZF1 in gastric cancer cells suppressed cell proliferation and migration, as well as the growth of xenograft tumors in nude mice. Knocking-down of MZF1 transformed GES-1 cells into a malignant phenotype characterized by increased cell growth and migration. Mechanistically, MZF1 was upregulated in both GC and GES-1 cells by MT2A ectopically expressed or induced upon treatment with a garlic-derived compound, diallyl trisulfide (DATS). MZF1 associated with MT2A was colocalized in the nuclei of GES-1 cells to target the promoter of NF-κB inhibitor alpha (NFKBIA). Clinically, MT2A and MZF1 were progressively downregulated in clinical specimens undergoing gastric malignant transformation. Downregulation of MT2A and MZF1 was significantly correlated with poorer patient prognosis.

CONCLUSIONS

MT2A exerts its anti-gastric cancer effects by complexing with MZF1 to target NFKBIA. MT2A/MZF1 may serve as a valuable prognostic marker and a novel therapeutic target for human gastric cancer.

Promoter hypermethylation of PIEZO2 is a risk factor and potential clinical biomarker for laryngeal squamous cell carcinoma

The aim of this study was to investigate the association between piezo type mechanosensitive ion channel component 2 (PIEZO2)-promoter methylation with and its clinical value for laryngeal squamous cell carcinoma (LSCC). Quantitative methylation-specific polymerase chain reaction technology was applied to measure PIEZO2 promoter methylation levels from 99 LSCC patients. Inclusive in the analysis were 133 (117 LSSC and 16 normal) samples from The Cancer Genome Atlas (TCGA). Our results showed significantly higher levels of PIEZO2 promoter methylation in LSCC than normal tissues (our cohort: P = 2.94E-21; TCGA cohort: P = 1.07E-19). In addition, PIEZO2 methylation was significantly associated with gender, differentiation, tumor (T) stage, lymph node metastasis, and clinical stage. The areas under the receiver characteristic curves (AUCs) based on our cohort and TCGA cohort were 0.917 and 0.978, respectively. Meanwhile, our study confirmed that PIEZO2 promoter hypermethylation could independently predict a poorer overall survival of LSCC patients (hazard ratio = 6.671; 95% confidence interval = 2.087-21.324). In conclusion, our study revealed that PIEZO2 promoter hypermethylation was a risk factor and might be involved in progression and metastasis, as well as serve as a potential clinical biomarker of LSCC.