Down-regulation of kallikrein-related peptidase 5 (KLK5) expression in breast cancer patients: a biomarker for the differential diagnosis of breast lesions

Kallikrein-related peptidase 5 contributes to the remodeling and repair of bronchial epithelium

Inflammation, oxidative stress, and protease/protease inhibitor imbalance with excessive production of proteases are factors associated with pathogenesis of the chronic obstructive pulmonary disease (COPD). In this study, we report that kallikrein-related peptidase 5 (KLK5) is a crucial protease involved in extracellular matrix (ECM) remodeling and bronchial epithelial repair after injury. First, we showed that KLK5 degrades the basal layer formed by culture of primary bronchial epithelial cells from COPD or non-COPD patients. Also, exogenous KLK5 acted differently on BEAS-2B cells already engaged in epithelial-to-mesenchymal transition (EMT) or on 16HBE 14o- cells harboring epithelial characteristics. Indeed, by inducing EMT, KLK5 reduced BEAS-2B cell adherence to the ECM. This effect, neutralized by tissue factor pathway inhibitor 2, a kunitz-type serine protease inhibitor, was due to a direct proteolytic activity of KLK5 on E-cadherin, β-catenin, fibronectin, and α5β1 integrin. Thus, KLK5 may strengthen EMT mechanisms and promote the migration of cells by activating the mitogen-activated protein kinase signaling pathway required for this function. In contrast, knockdown of endogenous KLK5 in 16HBE14o- cells, accelerated wound healing repair after injury, and exogenous KLK5 addition delayed the closure repair. These data suggest that among proteases, KLK5 could play a critical role in airway remodeling events associated with COPD during exposure of the pulmonary epithelium to inhaled irritants or smoking and the inflammation process.

Clinical significance of kallikrein 5 as a novel prognostic biomarker in gastric adenocarcinoma

Backgrounds

Gastric cancer is one of the most common cancers with unsatisfied prognosis. It is challenging to predict gastric cancer prognosis due to its highly heterogeneous nature. Kallikrein 5 (KLK5) belongs to the family of kallikreins, which plays a crucial role in serine proteolysis and exerts diverse physiological functions. The role of KLK5 in human gastric adenocarcinoma (GAC) has not been elucidated. In the present study, we aimed to examine the expression level of KLK5 and dissect whether the KLK5 expression was associated with GAC prognosis.

Patients and methods

Clinicopathological analyses were performed in a retrospective GAC patient cohort (n = 138). The expression of KLK5 was tested by quantitative RT‐PCR and immunohistochemistry staining. The prognostic role of KLK5 in GAC was assessed by univariate and multivariate analyses. The effects of KLK5 on cell proliferation, migration, and invasion were examined through cellular experiments.

Results

The data showed that KLK5 expression was elevated in GAC tissues compared with normal stomach tissues. Protein expression of KLK5 was positively correlated with tumor invasion depth and lymph node metastasis. Patients with higher KLK5 expression had poorer overall survival. KLK5 was identified to be an independent risk factor according to multivariate analysis. Using human GAC cell lines, we found that KLK5 can promote tumor cell migration and invasion.

Conclusions

Our study demonstrated that higher expression of KLK5 was significantly correlated with a poorer prognosis of GAC patients, implying the potential of KLK5 as a novel prognostic biomarker in GAC.

Search for Non-Protein Protease Inhibitors Constituted with an Indole and Acetylene Core

A possible inhibitor of proteases, which contains an indole core and an aromatic polar acetylene, was designed and synthesized. This indole derivative has a molecular architecture kindred to biologically relevant species and was obtained through five synthetic steps with an overall yield of 37% from the 2,2'-(phenylazanediyl)di(ethan-1-ol). The indole derivative was evaluated through docking assays using the main protease (SARS-CoV-2-M^pro) as a molecular target, which plays a key role in the replication process of this virus. Additionally, the indole derivative was evaluated as an inhibitor of the enzyme kallikrein 5 (KLK5), which is a serine protease that can be considered as an anticancer drug target.

Kallikrein-related Peptidase 5 (KLK5) Expression and Distribution in Canine Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is one of the most common types of malignant skin cancer in dogs, representing 3.9-10.4% of all canine skin tumours. Although the metastatic potential of cSCC is debated, it appears to mimic that observed in man. In man, predictive histopathological features for metastasis include tumour depth, lesions >5-6 mm in depth, and invasion of muscle, cartilage or bone. In dogs, some reports have focused on the clinical features and long-term progression of cSCC, but a gold standard treatment has not yet been developed. We explored the protein expression of kallikrein-related peptidase 5 (KLK5), an important modulator of skin homeostasis, in normal canine skin and in examples of cSCC. KLK5 was highly expressed in the upper stratum granulosum, stratum corneum, hair follicles and sweat glands, skin sites where human KLK5 has been shown to be involved in physiological processes including keratinocyte desquamation, antimicrobial defence, lipid permeability and pigmentation. In cSCC, tumour cells at the deep margin, as well as those in the centre of keratin pearls, displayed cytoplasmic expression of KLK5. Some of the KLK5 immunoreactive cells also expressed vimentin, suggesting that they may be undergoing epithelial-mesenchymal transition and therefore have a more invasive behaviour than those expressing only KLK5. KLK5 may be a novel molecular biomarker useful for predicting prognosis of cSSC in dogs.

Overview of tissue kallikrein and kallikrein-related peptidases in breast cancer

The kallikrein family comprises tissue kallikrein and 14 kallikrein-related peptidases (KLKs) recognized as a subgroup of secreted trypsin- or chymotrypsin-like serine proteases. KLKs are expressed in many cellular types where they regulate important physiological activities such as semen liquefaction, immune response, neural development, blood pressure, skin desquamation and tooth enamel formation. Tissue kallikrein, the oldest member and kinin-releasing enzyme, and KLK3/PSA, a tumor biomarker for prostate cancer are the most prominent components of the family. Additionally, other KLKs have shown an abnormal expression in neoplasia, particularly in breast cancer. Thus, increased levels of some KLKs may increase extracellular matrix degradation, invasion and metastasis; other KLKs modulate cell growth, survival and angiogenesis. On the contrary, KLKs can also inhibit angiogenesis and produce tumor suppression. However, there is a lack of knowledge on how KLKs are regulated in tumor microenvironment by molecules present at the site, namely cytokines, inflammatory mediators and growth factors. Little is known about the signaling pathways that control expression/secretion of KLKs in breast cancer, and further how activation of PAR receptors may contribute to functional activity in neoplasia. A better understanding of these molecular events will allow us to consider KLKs as relevant therapeutic targets for breast cancer.

Proteases are Modulated by Fascin in Oral Cancer Invasion

Background

Cancer invasion is a critical factor for survival and prognosis of patients with cancer. Identifying and targeting factors that influence cancer invasion are an important strategy to overcome cancer. In this study, we investigated the role of fascin known to be associated with cancer invasion.

Methods

Fascin depletion was performed with lentiviral short hairpin RNA against fascin mRNA and stable cell line (Fascin^dep) was established. Matrigel-Transwell invasion and three-dimensional (3D) culture system were used to observe fascin depletion effects. In order to observe the changes of protease secretion by fascin depleted cancer cells, protease antibody array was performed.

Results

Fascin was highly expressed in invasive cancer cells. Fascin-depleted cells showed decreased cancer invasion in Matrigel-Transwell invasion and 3D culture system. In addition, inhibition of proteases secreation and decrease of intracellular proteases mRNA expression were observed in fascin deplete cells.

Conclusions

These results indicates that fascin is closely involved in proteases activity and cancer invasion. Therefore, fascin is a strategically important factor for controlling cancer invasion.

Human kallikrein-related peptidase 12 (KLK12) splice variants discriminate benign from cancerous breast tumors

OBJECTIVES

As kallikrein-related peptidase 12 (KLK12) has been implicated in the cancer progression and alternative splicing plays significant role in this disease, the aim of this study was to examine the expression profile and the clinical impact of the KLK12 splice variants in breast cancer.

DESIGN AND METHODS

Total RNA was isolated and reverse transcripted from 141 tissues. Afterwards, quantitative real-time PCR were conducted, followed by the performance of the comparative CT (2-ΔΔCT) method for relative quantification, whilst their correlation with the clinicopathological features of breast malignancies were assessed by statistical analysis.

RESULTS

Both KLK12sv1/2 and KLK12sv3 showed higher expression in non-cancerous than in cancerous samples. KLKsv1/2 (P = 0.001) upregulated and KLK12sv3 (P < 0.001) downregulated in the malignant compared to the benign tumors and their discriminative ability was verified by ROC curve analysis. Moreover, KLK12sv3 was associated with grade (P = 0.012) and hormonal receptor status (P = 0.001). Furthermore, Kaplan-Meier and Cox regression analyses showed that patients with positive KLK12sv1/2 and KLK12sv3 levels presented a significantly longer disease-free survival (P = 0.014 and P = 0.013, respectively) and overall survival (P = 0.062 and P = 0.004, respectively).

CONCLUSIONS

Our results demonstrate the discriminative value of KLK12sv1/2 and KLK12sv3 between benign and malignant breast tumors as well as their potential favorable prognostic significance in breast adenocarcinoma.

Transcriptome profiling of cancer and normal tissues from cervical squamous cancer patients by deep sequencing

Cervical cancer is the fourth leading cause of cancer mortality in women worldwide. High‑risk human papillomavirus infection is a major cause of cervical cancer. A previous study revealed the role of different oncogenes and tumor suppressors in cervical cancer initiation and progression. However, the complicated genetic network regulating cervical cancer remains largely unknown. The present study reported transcriptome sequencing analysis of three cervical squamous cell cancer tissues and paired normal cervical tissues. Transcriptomic analysis revealed that 2,519 genes were differently expressed between cervical cancer tissues and their corresponding normal tissues. Among these, 236 differentially expressed genes (DEGs) were statistically significant, including many DEGs that were novel in cervical cancer, including gastrulation brain homeobox 2,5‑hydroxytryptamine receptor 1D and endothelin 3. These 236 significant DEGs were highly enriched in 28 functional gene ontology categories. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis suggested involvement of these DEGs in multiple pathways. The present study provides a transcriptome landscape of cervical cancer in Chinese patients and an improved understanding of the genetic regulatory network in cervical cancer tumorigenesis.

mRNA overexpression of kallikrein-related peptidase 14 (KLK14) is an independent predictor of poor overall survival in chronic lymphocytic leukemia patients

BACKGROUND

Tissue kallikrein and kallikrein-related peptidases (KLKs) compose a family of serine endopeptidases with much clinical interest in oncology, as their potential as diagnostic and/or prognostic molecular biomarkers in several human malignancies has already been evidenced. However, none of the members of this family has ever been studied in hematological malignancies. Based on our preliminary results regarding the differential mRNA expression of several KLK genes in peripheral blood mononuclear cells (PBMCs) of patients with chronic lymphocytic leukemia (CLL) compared to healthy blood donors, we decided to study the diagnostic and prognostic potential of KLK14 mRNA expression in CLL.

METHODS

Total RNA was isolated from 69 CLL patients and 31 non-leukemic blood donors. After reverse transcription of poly(A)-RNA, KLK14 mRNA levels were quantified using a sensitive and accurate quantitative real-time PCR (qPCR) methodology.

RESULTS

According to ROC analysis, KLK14 mRNA overexpression successfully discriminated CLL patients from normal population (area under the curve [AUC] 0.89, 95% confidence interval [CI] 0.83-0.95, p<0.001). Moreover, although not clearly related to clinical staging or other prognostic factors including IGHV mutational status and CD38 expression, strong KLK14 mRNA expression was shown to predict reduced overall survival of CLL patients (p=0.026) using Kaplan-Meier survival analysis. The unfavorable prognostic value of KLK14 mRNA overexpression in CLL patients' PBMCs was independent of established prognostic factors of the disease, as shown by multivariate Cox regression analysis (hazard ratio [HR] 14.65, 95% CI 1.81-118.36, p=0.012).

CONCLUSIONS

KLK14 mRNA expression merits further investigation as a potential prognostic biomarker of overall survival of patients with CLL.

Non-coding RNAs profiling in head and neck cancers

The majority of studies on human cancers published to date focus on coding genes. More recently, however, non-coding RNAs (ncRNAs) are gaining growing recognition as important regulatory components. Here we characterise the ncRNA landscape in 442 head and neck squamous cell carcinomas (HNSCs) from the cancer genome atlas (TCGA). HNSCs represent an intriguing case to study the potential role of ncRNA as a function of viral presence, especially as HPV is potentially oncogenic. Thus, we identify HPV16-positive (HPV16⁺) and HPV-negative (HPV⁻) tumours and study the expression of ncRNAs on both groups. Overall, the ncRNAs comprise 36% of all differentially expressed genes, with antisense RNAs being the most represented ncRNA type (12.6%). Protein-coding genes appear to be more frequently downregulated in tumours compared with controls, whereas ncRNAs show significant upregulation in tumours, especially in HPV16⁺ tumours. Overall, expression of pseudogenes, antisense and short RNAs is elevated in HPV16⁺ tumours, while the remaining long non-coding RNA types are more active in all HNSC tumours independent of HPV status. In addition, we identify putative regulatory targets of differentially expressed ncRNAs. Among these ‘targets’ we find several well-established oncogenes, tumour suppressors, cytokines, growth factors and cell differentiation genes, which indicates the potential involvement of ncRNA in the control of these key regulators as a direct consequence of HPV oncogenic activity. In conclusion, our findings establish the ncRNAs as crucial transcriptional components in HNSCs. Our results display the great potential for the study of ncRNAs and the role they have in human cancers.

Kallikrein-related peptidase 5 induces miRNA-mediated anti-oncogenic pathways in breast cancer

Kallikrein-related peptidase 5 (KLK5) displays aberrant expression in cancer. Recently, we showed KLK5 reconstitution in breast cancer cell lines suppresses malignancy. Present study aims to investigate the functional KLK5 mediated miRNA network on breast cancer progression, molecular subtype and survival.

28 miRNAs were up-regulated and 62 miRNAs were down-regulated upon KLK5 expression. Extracellular matrix (ECM) molecules and cell-adhesion pathways were the most significant KLK5-induced miRNA-mediated regulatory targets. Validation from The Cancer Genome Atlas (TCGA) database indicated KLK5 was specifically down-regulated in luminal B and basal-like breast cancer subtypes. There was a correlation between KLK5, miRNAs and their downstream ECM gene targets. Long-term patient survival correlated with dysregulation of KLK5 and interacting ECM target genes. It suggests biological differences between breast cancer molecular subtypes, patient survival, and their propensity for invasion and metastasis can be explained in part by altered miRNA networks induced by KLK5 dysregulation.

We provide the first evidence that KLK5 can affect miRNA networks, which regulate MMPs and other novel ECM targets and a new compelling hypothesis of interplay between serine proteases and miRNAs. We developed a combined KLK5-(ITGB1+COL12A1) predictive score for recurrence-free survival that could be exploited in clinical applications.

Overexpression of kallikrein gene 10 is a biomarker for predicting poor prognosis in gastric cancer

AIM: To analyze the expression of kallikrein gene 10 (KLK10) in gastric cancer and to determine whether KLK10 has independent prognostic value in gastric cancer.

METHODS: We studied KLK10 expression in 80 histologically confirmed gastric cancer samples using real-time quantitative reverse transcription-PCR and hK10 expression using immunohistochemistry. Correlations with clinicopathological variables (lymph node metastasis, depth of invasion and histology) and with outcomes (disease-free survival and overall survival) during a median follow-up period of 31 mo were assessed. Gastric cancer tissues were then classified as KLK10 positive or negative.

RESULTS: KLK10 was found to be highly expressed in 57/80 (70%) of gastric cancer samples, while its expression was very low in normal gastric tissues. Positive relationships between KLK10 expression and lymph node metastasis (P = 0.048), depth of invasion (P = 0.034) and histology (P = 0.015) were observed. Univariate survival analysis revealed that gastric cancer patients with positive KLK10 expression had an increased risk for relapse/metastasis and death (P = 0.005 and 0.002, respectively). Cox multivariate analysis indicated that KLK10 was an independent prognostic indicator of disease-free survival and overall survival in patients with gastric cancer.

CONCLUSION: KLK10 expression is an independent biomarker of unfavorable prognosis in patients with gastric cancer.

The kinin-kallikrein system: physiological roles, pathophysiology and its relationship to cancer biomarkers

The kinin-kallikrein system (KKS) is an endogenous multiprotein cascade, the activation of which leads to triggering of the intrinsic coagulation pathway and enzymatic hydrolysis of kininogens with the consequent release of bradykinin-related peptides. This system plays a crucial role in inflammation, vasodilation, smooth muscle contraction, cardioprotection, vascular permeability, blood pressure control, coagulation and pain. In this review, we will outline the physiology and pathophysiology of the KKS and also highlight the association of this system with carcinogenesis and cancer progression.

Significant alterations in the expression pattern of kallikrein-related peptidase genes KLK4, KLK5 and KLK14 after treatment of breast cancer cells with the chemotherapeutic agents epirubicin, docetaxel and methotrexate

Given that 1.3 million new cases of breast cancer are universally registered among women and approximately 36 % of the patients die annually, the revelation of new predictive markers for treatment efficiency is of vital importance. Recently, our group has depicted that KLK4, KLK5, and KLK14 are differentially expressed in breast carcinoma. The objective of this study was to determine and investigate the expression pattern of the KLK4, KLK5, and KLK14 genes in breast cancer cells after treatment with established chemotherapeutic agents. We evaluated these genes' expression after treatment of the BT-20 cells with epirubicin, docetaxel and methotrexate, determining their cytotoxic effect by MTT and trypan blue assays. The relative quantification of genes' mRNA levels was performed by using the SYBR Green® chemistry, and the HPRT1 served as an endogenous control gene. The drugs triggered apoptosis in treated cells and induced deregulations in the expression of the above KLKs. The most significant alterations were a 12-fold and tenfold increase of KLK5 in docetaxel and methotrexate-treated cells, respectively, while the KLK4 levels decreased by ten-fold in epirubicin, five-fold in docetaxel and twenty-fold in methotrexate treated-cells, compared to the untreated ones. In the case of KLK14 levels, a twofold increase in epirubicin and threefold decrease in methotrexate-treated cells were observed. Present significant alterations in the expression pattern of KLK4, KLK5, and KLK14 could comprise an initial stage for predicting chemotherapy response in breast cancer and should be further investigated as predictive markers in the future.

Circulating microRNA-92a and microRNA-21 as novel minimally invasive biomarkers for primary breast cancer

PURPOSE

MicroRNAs (miRNAs) play an essential role in breast malignant tumor development and progression. The development of clinically validated biomarkers for primary breast cancer (BC) has remained an insurmountable task despite other advances in the field of cancer molecular biology. The objective of this study is to investigate the differential expression of miRNAs and the potential of circulating microRNAs as novel primary breast cancer biomarkers.

METHODS

Our analyses were performed on 48 tissue and 100 serum samples of patients with primary BC and a set of 20 control samples of healthy women, respectively. The relative expression of ten candidate miRNAs (miR-106b, miR-125b, miR-17, miR-185, miR-21, miR-558, miR-625, miR-665, miR-92a, and miR-93) from the results of four bioinformatics approaches and literature curation was measured by real-time quantitative reverse transcription PCR (qRT-PCR).

RESULTS

The level of miR-92a was significantly lower, while miR-21 was higher, as previous reports, in tissue and serum samples of BC than that of healthy controls (p < 0.001). Logistic regression and receiver operating characteristic curve analyses revealed the significant and independent value (p < 0.001) of the miR-92a and miR-21 expression quantification in serums. Moreover, the comparison with the clinicopathologic data of the BC patients showed that decreased levels of miR-92a and increased levels of miR-21 were associated with tumor size and a positive lymph node status (p < 0.001).

CONCLUSIONS

These findings suggest that many miRNAs expressions are altered in BC, whose expression profiling may provide a useful clue for the pathophysiological research. Circulating miR-92a has potential use as novel breast cancer biomarker, which is comparable to miR-21.