Impact of suppression of tumorigenicity 14 (ST14)/serine protease 14 (Prss14) expression analysis on the prognosis and management of estrogen receptor negative breast cancer

Environment-Sensitive Ectodomain Shedding of Epithin/PRSS14 Increases Metastatic Potential of Breast Cancer Cells by Producing CCL2

Epithin/PRSS14 is a membrane serine protease that plays a key role in tumor progression. The protease exists on the cell surface until its ectodomain shedding, which releases most of the extracellular domain. Previously, we showed that the remaining portion on the membrane undergoes intramembrane proteolysis, which results in the liberation of the intracellular domain and the intracellular domainmediated gene expression. In this study, we investigated how the intramembrane proteolysis for the nuclear function is initiated. We observed that ectodomain shedding of epithin/PRSS14 in mouse breast cancer 4T1 cells increased depending on environmental conditions and was positively correlated with invasiveness of the cells and their proinvasive cytokine production. We identified selenite as an environmental factor that can induce ectodomain shedding of the protease and increase C-C motif chemokine ligand 2 (CCL2) secretion in an epithin/PRSS14-dependent manner. Additionally, by demonstrating that the expression of the intracellular domain of epithin/PRSS14 is sufficient to induce CCL2 secretion, we established that epithin/PRSS14- dependent shedding and its subsequent intramembrane proteolysis are responsible for the metastatic conversion of 4T1 cells under these conditions. Consequently, we propose that epithin/PRSS14 can act as an environment-sensing receptor that promotes cancer metastasis by liberating the intracellular domain bearing transcriptional activity under conditions promoting ectodomain shedding.

Biological Prognostic Value of miR-155 for Survival Outcome in Head and Neck Squamous Cell Carcinomas: Systematic Review, Meta-Analysis and Trial Sequential Analysis

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide; in fact, it is among the top six neoplasms, with an incidence of about 370,000 new cases per year. The 5-year survival rate, despite chemotherapy, radiotherapy, and surgery for stages 3 and 4 of the disease, is low. MicroRNAs (miRNAs) are a large group of small single-stranded non-coding endogenous RNAs, approximately 18-25 nucleotides in length, that play a significant role in the post-transcriptional regulation of genes. Recent studies investigated the tissue expression of miR-155 as a prognostic biomarker of survival in HNSCC. The purpose of this systematic review is, therefore, to investigate and summarize the current findings in the literature concerning the potential prognostic expression of tissue miR-155 in patients with HNSCC. The revision was performed according to PRISMA indications: three databases (PubMed, Scopus, and the Cochrane Register) were consulted through the use of keywords relevant to the revision topic. Totally, eight studies were included and meta-analyzed. The main results report for the aggregate HR values of 1.40 for OS, 1.36 for DFS, and 1.09 for DPS. Finally, a trial sequencing analysis was also conducted to test the robustness of the proposed meta-analysis.

Gene-associated methylation status of ST14 as a predictor of survival and hormone receptor positivity in breast Cancer

Background

Genomic profiles of specific gene sets have been established to guide personalized treatment and prognosis for patients with breast cancer (BC). However, epigenomic information has not yet been applied in a clinical setting. ST14 encodes matriptase, a proteinase that is widely expressed in BC with reported prognostic value.

Methods

In this present study, we evaluated the effect of ST14 DNA methylation (DNAm) on overall survival (OS) of patients with BC as a representative example to promote the use of the epigenome in clinical decisions. We analyzed publicly available genomic and epigenomic data from 1361 BC patients. Methylation was characterized by the β-value from CpG probes based on sequencing with the Illumina Human 450 K platform.

Results

A high mean DNAm (β > 0.6779) across 34 CpG probes for ST14, as the gene-associated methylation (GAM) pattern, was associated with a longer OS after adjusting age, stage, histology and molecular features in Cox model (p value < 0.001). A high GAM status was also associated with a higher XBP1 expression level and higher proportion of hormone-positive BC (p value < 0.001). Pathway analysis revealed that altered GAM was related to matrisome-associated pathway.

Conclusions

Here we show the potential role of ST14 DNAm in BC prognosis and warrant further study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08645-3.

Critical Adjuvant Influences on Preventive Anti-Metastasis Vaccine Using a Structural Epitope Derived from Membrane Type Protease PRSS14

We tested how adjuvants effect in a cancer vaccine model using an epitope derived from an autoactivation loop of membrane-type protease serine protease 14 (PRSS14; loop metavaccine) in mouse mammary tumor virus (MMTV)-polyoma middle tumor-antigen (PyMT) system and in 2 other orthotopic mouse systems. Earlier, we reported that loop metavaccine effectively prevented progression and metastasis regardless of adjuvant types and T_H types of hosts in tail-vein injection systems. However, the loop metavaccine with Freund's complete adjuvant (CFA) reduced cancer progression and metastasis while that with alum, to our surprise, were adversely affected in 3 tumor bearing mouse models. The amounts of loop peptide specific antibodies inversely correlated with tumor burden and metastasis, meanwhile both T_H1 and T_H2 isotypes were present regardless of host type and adjuvant. Tumor infiltrating myeloid cells such as eosinophil, monocyte, and neutrophil were asymmetrically distributed among 2 adjuvant groups with loop metavaccine. Systemic expression profiling using the lymph nodes of the differentially immunized MMTV-PyMT mouse revealed that adjuvant types, as well as loop metavaccine can change the immune signatures. Specifically, loop metavaccine itself induces T_H2 and T_H17 responses but reduces T_H1 and T_reg responses regardless of adjuvant type, whereas CFA but not alum increased follicular T_H response. Among the myeloid signatures, eosinophil was most distinct between CFA and alum. Survival analysis of breast cancer patients showed that eosinophil chemokines can be useful prognostic factors in PRSS14 positive patients. Based on these observations, we concluded that multiple immune parameters are to be considered when applying a vaccine strategy to cancer patients.

Reverse engineering a predictive signature characterized by proliferation, DNA damage, and immune escape from stage I lung adenocarcinoma recurrence

Identifying early-stage cancer patients at risk for progression is a major goal of biomarker research. This report describes a novel 19-gene signature (19-GCS) that predicts stage I lung adenocarcinoma (LAC) recurrence and response to therapy and performs comparably in pancreatic adenocarcinoma (PAC), which shares LAC molecular traits. Kaplan-Meier, Cox regression, and cross-validation analyses were used to build the signature from training, test, and validation sets comprising 831 stage I LAC transcriptomes from multiple independent data sets. A statistical analysis was performed using the R language. Pathway and gene set enrichment were used to identify underlying mechanisms. 19-GCS strongly predicts overall survival and recurrence-free survival in stage I LAC (P=0.002 and P<0.001, respectively) and in stage I-II PAC (P<0.0001 and P<0.0005, respectively). A multivariate cox regression analysis demonstrated the independence of 19-GCS from significant clinical factors. Pathway analyses revealed that 19-GCS high-risk LAC and PAC tumors are characterized by increased proliferation, enhanced stemness, DNA repair deficiency, and compromised MHC class I and II antigen presentation along with decreased immune infiltration. Importantly, high-risk LAC patients do not appear to benefit from adjuvant cisplatin while PAC patients derive additional benefit from FOLFIRINOX compared with gemcitabine-based regimens. When validated prospectively, this proof-of-concept biomarker may contribute to tailoring treatment, recurrence reduction, and survival improvements in early-stage lung and pancreatic cancers.

Intramembrane proteolysis of an extracellular serine protease, epithin/PRSS14, enables its intracellular nuclear function

BACKGROUND

Epithin/PRSS14, a type II transmembrane serine protease, is an emerging target of cancer therapy because of its critical roles in tumor progression and metastasis. In many circumstances, the protease, through its ectodomain shedding, exists as a soluble form and performs its proteolytic functions in extracellular environments increasing cellular invasiveness. The seemingly functional integrity of the soluble form raises the question of why the protease is initially made as a membrane-associated protein.

RESULTS

In this report, we show that the epithin/PRSS14 intracellular domain (EICD) can be released from the membrane by the action of signal peptide peptidase-like 2b (SPPL2b) after ectodomain shedding. The EICD preferentially localizes in the nucleus and can enhance migration, invasion, and metastasis of epithelial cancer when heterologously expressed. Unbiased RNA-seq analysis and subsequent antibody arrays showed that EICD could control the gene expression of chemokines involved in cell motility, by increasing their promoter activities. Finally, bioinformatics analysis provided evidence for the clinical significance of the intramembrane proteolysis of epithin/PRSS14 by revealing that the poor survival of estrogen receptor (ER)-negative breast cancer patients with high epithin/PRSS14 expression is further worsened by high levels of SPPL2b.

CONCLUSIONS

These results show that ectodomain shedding of epithin/PRSS14 can initiate a unique and synchronized bidirectional signal for cancer metastasis: extracellularly broadening proteolytic modification of the surrounding environment and intracellularly reprogramming the transcriptome for metastatic conversion. Clinically, this study also suggests that the intracellular function of epithin/PRSS14 should be considered for targeting this protease for anti-cancer treatment.

A JUN N-terminal kinase inhibitor induces ectodomain shedding of the cancer-associated membrane protease Prss14/epithin via protein kinase CβII

Serine protease 14 (Prss14)/epithin is a transmembrane serine protease that plays essential roles in tumor progression and metastasis and therefore is a promising target for managing cancer. Prss14/epithin shedding may underlie its activity in cancer and worsen outcomes; accordingly, a detailed understanding of the molecular mechanisms in Prss14/epithin shedding may inform the design of future cancer therapies. On the basis of our previous observation that an activator of PKC, phorbol 12-myristate 13-acetate (PMA), induces Prss14/epithin shedding, here we further investigated the intracellular signaling pathway involved in this process. While using mitogen-activated protein kinase inhibitors to investigate possible effectors of downstream PKC signaling, we unexpectedly found that an inhibitor of c-Jun N-terminal kinase (JNK), SP600125, induces Prss14/epithin shedding even in the absence of PMA. SP600125-induced shedding, like that stimulated by PMA, was mediated by tumor necrosis factor-α–converting enzyme. In contrast, a JNK activator, anisomycin, partially abolished the effects of SP600125 on Prss14/epithin shedding. Moreover, the results from loss-of-function experiments with specific inhibitors, short hairpin RNA–mediated knockdown, and overexpression of dominant-negative PKCβII variants indicated that PKCβII is a major player in JNK inhibition– and PMA-mediated Prss14/epithin shedding. SP600125 increased phosphorylation of PKCβII and tumor necrosis factor-α–converting enzyme and induced their translocation into the plasma membrane. Finally, in vitro cell invasion experiments and bioinformatics analysis of data in The Cancer Genome Atlas breast cancer database revealed that JNK and PKCβII are important for Prss14/epithin-mediated cancer progression. These results provide important information regarding strategies against tumor metastasis.

Targeting metastatic breast cancer with peptide epitopes derived from autocatalytic loop of Prss14/ST14 membrane serine protease and with monoclonal antibodies

Background

In order to develop a new immunotherapeutic agent targeting metastatic breast cancers, we chose to utilize autocatalytic feature of the membrane serine protease Prss14/ST14, a specific prognosis marker for ER negative breast cancer as a target molecule.

Methods

The study was conducted using three mouse breast cancer models, 4 T1 and E0771 mouse breast cancer cells into their syngeneic hosts, and an MMTV-PyMT transgenic mouse strain was used. Prss14/ST14 knockdown cells were used to test function in tumor growth and metastasis, peptides derived from the autocatalytic loop for activation were tested as preventive metastasis vaccine, and monoclonal and humanized antibodies to the same epitope were tested as new therapeutic candidates. ELISA, immunoprecipitation, Immunofluorescent staining, and flow cytometry were used to examine antigen binding. The functions of antibodies were tested in vitro for cell migration and in vivo for tumor growth and metastasis.

Results

Prss14/ST14 is critically involved in the metastasis of breast cancer and poor survival rather than primary tumor growth in two mouse models. The epitopes derived from the specific autocatalytic loop region of Prss14/ST14, based on structural modeling acted as efficient preventive metastasis vaccines in mice. A new specific monoclonal antibody mAb3F3 generated against the engineered loop structure could reduce cell migration, eliminate metastasis in PyMT mice, and can detect the Prss14/ST14 protein expressed in various human cancer cells. Humanized antibody huAb3F3 maintained the specificity and reduced the migration of human breast cancer cells in vitro.

Conclusion

Our study demonstrates that Prss14/ST14 is an important target for modulating metastasis. Our newly developed hybridoma mAbs and humanized antibody can be further developed as new promising candidates for the use in diagnosis and in immunotherapy of human metastatic breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1373-y) contains supplementary material, which is available to authorized users.

Effect of the normal mammary differentiation regulator ELF5 upon clinical outcomes of triple negative breast cancers patients

BACKGROUND

Elf5 is a transcription factor previously shown to be involved in regulating cell differentiation in both normal and pathological breast tissues. Pertinently, Elf5 was reported to interact with the FOXA1 transcription factor, a pivotal regulatory factor in a subset of AR overexpressing triple negative cancer (TNBC) cases.

METHODS

We examined the correlation among AR, FOXA1, and Elf5 expression in a series of TNBC cases. The cases were retrieved from surgical pathological files of Tohoku University Hospital Japan and consisted of 60 cases operated between the year 1999 and 2007. An additional cohort cases of 51 TNBC ductal carcinoma in situ was used to compare invasive and non-invasive TNBC.

RESULTS

In our cohort, 47% of all carcinomas were positive for Elf5, with a significantly higher proportion of Elf5 positive cases occurring in the younger age groups (p = 0.0061). Elf5 immunoreactivity was not associated with any other clinicopathological factors examined in this study. However, Elf5 expression was associated with decreased overall and disease-free survival of the patients (Peto-Peto modification of Gehan-Wilcoxon test, OS p = 0.132, DFS p = 0.1 (LI cutoff 10%); OS p = 0.038, DFS p = 0.021 (LI cutoff 50%)). Of particular interest, its effects on survival were more pronounced in the EGFR-/CK5/6- (non-basal surrogate) than the EGFR+ and/or CK5/6+ (basal-surrogate) subtype of TNBC.

CONCLUSIONS

Elf5 is present in TNBC and its status was significantly correlated with overall survival of the patients. Further studies examining possible interactions between Elf5 and other factors in TNBC could contribute to disentangling TNBC biology.

Disruption of TACE-filamin interaction can inhibit TACE-mediated ectodomain shedding

Ectodomain shedding regulates functions of many membrane proteins through the cleavage of their juxtamembrane region mainly by a disintegrin and metalloproteinase family proteinases. Tumor necrosis factor-alpha converting enzyme (TACE) is known to be responsible for phorbol myristate acetate (PMA)-induced shedding of various membrane proteins. How PMA regulates TACE-dependent shedding and how TACE exhibits substrate specificity without proteolysis of other membrane proteins are questionable. Here, we show that TACE can interact with an actin-binding protein, filamin, through 20th filamin repeat. We found that the interaction between TACE and filamin was increased by PMA treatment. In addition, loss of filamin or specific disruption of TACE-filamin interaction inhibited ectodomain shedding of representative TACE substrates, CD44 and amyloid protein precursor. From these data, we suggest that filamin may work as a scaffold that can recruit TACE and its substrates in a PMA-dependent manner to achieve substrate specificity for TACE.