Correlation of the expression of human kallikrein-related peptidases 4 and 7 with the prognosis in oral squamous cell carcinoma

KLK7 expression in human tumors: a tissue microarray study on 13,447 tumors

BACKGROUND

Kallikrein-related peptidase 7 (KLK7) is a chymotrypsin-like serine protease which is essential for the desquamation of corneocytes and thus plays a pivotal role in maintaining skin homeostasis. In cancer, KLK7 overexpression was suggested to represent a route for metastasis through cleavage of cell junction and extracellular matrix proteins of cancer cells.

METHODS

To comprehensively determine KLK7 protein expression in normal and neoplastic tissues, a tissue microarray containing 13,447 samples from 147 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry.

RESULTS

KLK7 positivity was found in 64 of 147 tumor categories, including 17 tumor categories with at least one strongly positive case. The highest rate of KLK7 positivity was found in squamous cell carcinomas from various sites of origin (positive in 18.1%-63.8%), ovarian and endometrium cancers (4.8%-56.2%), salivary gland tumors (4.8%-13.7%), bilio-pancreatic adenocarcinomas (20.0%-40.4%), and adenocarcinomas of the upper gastrointestinal tract (3.3%-12.5%). KLK7 positivity was linked to nodal metastasis (p = 0.0005), blood vessel infiltration (p = 0.0037), and lymph vessel infiltration (p < 0.0001) in colorectal adenocarcinoma, nodal metastasis in hepatocellular carcinoma (p = 0.0382), advanced pathological tumor stage in papillary thyroid cancer (p = 0.0132), and low grade of malignancy in a cohort of 719 squamous cell carcinomas from 11 different sites of origin (p < 0.0001).

CONCLUSIONS

These data provide a comprehensive overview on KLK7 expression in normal and neoplastic human tissues. The prognostic relevance of KLK7 expression and the possible role of KLK7 as a drug target need to be further investigated.

Evaluation of hTERT, KRT7, and survivin in urine for noninvasive detection of bladder cancer using real-time PCR

Background

Transitional cell carcinoma (TCC) of the bladder is the second most common genitourinary malignancy. Because of the low sensitivity of urinary cytology and the invasiveness and expense of frequent cystoscopies for the detection of low-grade superficial lesions, we aim to establish a sensitive molecular approach to detect bladder cancer noninvasively.

Methods

Voided urine samples were collected from 80 patients with bladder cancer at the time of diagnosis, in addition to 30 patients with non-bladder cancer urological diseases and 20 healthy volunteers. The level of hTERT, KRT7, and survivin (SVV) mRNAs were analyzed using a qRT-PCR assay.

Results

The optimal threshold values for hTERT, KRT7, and SVV in urine were calculated by ROC curves analysis. The overall sensitivity was 81.3%, 91.3%, and 68.8% for hTERT, KRT7, and SVV, respectively, which were significantly higher than urine cytology (22.2%, p < 0.001). A higher positive ratio was obtained using multi-marker detection in comparison to single marker detection. The combined use of markers increased the sensitivity of cytology from 22.2 to 100%. In contrast with the urine cytology method, the sensitivity of these biomarkers was not correlated with the grades and stages of the bladder tumors.

Conclusions

Our data indicate that urinary hTERT, KRT7, and SVV have superior sensitivities over cytology. The combined use of these markers offers a powerful potential assay and promising tool for a sensitive, noninvasive, and highly specific diagnostic method and follow-up of low-grade TCC of the bladder.

Immunohistochemical expression of kallikrein 7 in oral squamous cell carcinoma

Background and Objectives:

The kallikrein (KLK) family of genes consists of 15 members, many of which are highly expressed in number of cancers compared to their normal parent tissues. KLK7 was initially characterized as an enzyme implicated in the degradation of intercellular cohesive structures in the stratum corneum of stratified squamous epithelia, preceding desquamation in the skin. It catalyzes the degradation of desmosomes in the outermost layer of skin and permits cell shedding to take place at the skin surface. Overexpression of KLK7 in tumor cells has been reported to significantly enhance the invasive potential in intracranial malignancies and ovarian cancer cells. Thus, KLK7 could contribute to the degradation of extracellular matrices in oral squamous cell carcinoma (OSCC) tissues, promoting invasion of neoplastic cells locally and facilitating metastasis to regional lymph nodes. The objectives of the present study were to compare the expression of KLK 7 in normal subjects and patients with OSCC, to correlate the expression of KLK 7 with respect to the clinical staging of OSCC and to evaluate the expression of KLK 7with respect to different histopathological grades of OSCC.

Materials and Methods:

Thirty cases of OSCC were staged clinically and graded histopathologically. The immunohistochemical method was used to detect the expression of KLK 7 in OSCC. The scores obtained were documented and compared statistically.

Results:

KLK 7 immunoreactivity was noticed in all cases of OSCC. A statistically significant difference was observed in immunoreactivity of KLK 7 between the normal and OSCC (P = 0.0001*) and in different histopathological grades (P = 0.0001*) and in different clinical stages (P = 0.0127*) of OSCC using Kruskal–Wallis analysis of variance test.

Conclusion:

The KLK 7 immunoexpression histopathologically increased from low grade to high grade and clinically from Stage 1 to Stage 4 in OSCC. Hence, increased expression of KLK 7 may be related to poor prognosis in patients with OSCC.

Kallikrein 4 and matrix metalloproteinase-20 immunoexpression in malignant, benign and infiltrative odontogenic tumors

CONTEXT

Matrix metalloproteinase-20 (MMP20) (enamelysin) and kallikrein 4 (KLK4) are enzymes secreted by ameloblasts that play an important role in enamel matrix degradation during amelogenesis. However, studies have shown that neoplastic cells can produce such enzymes, which may affect the tumor infiltrative and metastatic behaviors.

AIMS

The aim of this study is to assess the biological role of MMP20 and KLK4 in odontogenic tumors.

MATERIALS AND METHODS

The enzymes were analyzed immunohistochemically in ameloblastoma, adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor, keratocystic odontogenic tumor with or without recurrence and odontogenic carcinoma.

STATISTICAL ANALYSIS USED

Clinicopathological parameters were statistically correlated with protein expression using the Fisher's exact test. Kruskal-Wallis and Wilcoxon-independent methods were used to evaluate the differences in median values.

RESULTS

Positive Immunoexpression was detected in all benign lesions, with a prevalence of 75-100% immunolabeled cells. Patients were predominantly young, Caucasian, female, with slow-growing tumors located in the mandible causing asymptomatic swelling. No KLK4 expression was seen in carcinomas, and the amount of MMP20-positive cells varied between 20% and 80%. Rapid evolution, recurrence and age >60 years characterized the malignant nature of these lesions.

CONCLUSIONS

Data showed that KLK4 and MMP20 enzymes may not be crucial to tumoral infiltrative capacity, especially in malignant tumors, considering the diversity and peculiarity of these lesions. The significant immunoexpression in benign lesions, remarkably in AOT, is likely associated with differentiated tumor cells that can produce and degrade enamel matrix-like substances. This would be expected since the histogenesis of odontogenic tumors commonly comes from epithelium that recently performed a secretory activity in tooth formation.

Involvement of Kallikrein-Related Peptidases in Normal and Pathologic Processes

Human kallikrein-related peptidases (KLKs) are a subgroup of serine proteases that participate in proteolytic pathways and control protein levels in normal physiology as well as in several pathological conditions. Their complex network of stimulatory and inhibitory interactions may induce inflammatory and immune responses and contribute to the neoplastic phenotype through the regulation of several cellular processes, such as proliferation, survival, migration, and invasion. This family of proteases, which includes one of the most useful cancer biomarkers, kallikrein-related peptidase 3 or PSA, also has a protective effect against cancer promoting apoptosis or counteracting angiogenesis and cell proliferation. Therefore, they represent attractive therapeutic targets and may have important applications in clinical oncology. Despite being intensively studied, many gaps in our knowledge on several molecular aspects of KLK functions still exist. This review aims to summarize recent data on their involvement in different processes related to health and disease, in particular those directly or indirectly linked to the neoplastic process.

KLK11 mRNA expression predicts poor disease-free and overall survival in colorectal adenocarcinoma patients

BACKGROUND

Dysregulated expression of several KLK family members has been observed in colorectal adenocarcinoma. In the present study, the prognostic value of KLK11 mRNA expression as a molecular tissue biomarker in colorectal adenocarcinoma was examined.

MATERIALS & METHODS

Using quantitative real-time PCR, KLK11 mRNA expression was studied in 120 cancerous and 41 paired noncancerous colorectal specimens obtained from 120 patients with primary colorectal adenocarcinoma.

RESULTS

A significant upregulation of KLK11 transcripts in colorectal tumors was observed. KLK11 mRNA expression was associated with the depth of tumor invasion and the histological grade. Furthermore, KLK11 mRNA expression predicted poor disease-free and overall survival, independently of patient gender, age, tumor size, location, histological subtype, grade, venous invasion, lymphatic invasion, TNM stage, radiotherapy and chemotherapy treatment.

CONCLUSION

KLK11 mRNA expression could be considered as a new molecular prognostic biomarker in colorectal adenocarcinoma, with additional prognostic value in patients with highly invasive tumors and/or positive lymph nodes.

Polymorphisms in Kallikrein7 and 10 genes and oral cancer risks in Taiwan betel quid chewers and smokers

OBJECTIVES

We investigated the association between mRNA levels, polymorphisms of Kallikrein7 (KLK7) and Kallikrein10 (KLK10), and the development of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

We recruited 217 OSCC patients and 138 healthy controls. All were men, betel quid chewers, cigarette smokers, and Minnan ethnicity. Genotyping was performed using a TaqMan probe genotyping assay. Gene expression levels were determined using real-time polymerase chain reactions (PCRs) for 20 pairs of cancerous and non-cancerous tissues.

RESULTS

Kallikrein10 rs3745535G>T polymorphisms were significantly associated with OSCC development [adjusted OR (AOR) = 1.62, 95% CI = 1.02-2.59], but KLK7 polymorphisms were not. The KLK7 rs10581213(wt/ins + ins/ins) genotypes were significantly associated with early-stage cancer (AOR = 0.34, 95% CI = 0.14-0.78), but KLK10 polymorphisms were not. Relative expression analysis indicated that an increase in KLK7 and KLK10 mRNA levels was found in cancerous tissues (2(-ΔΔCT) = 25.23 ± 8.85 and 10.89 ± 4.97, respectively). A significantly higher level of KLK7 was expressed in early-stage cancer with the rs10581213(wt/ins + ins/ins) genotypes, but there was no significant difference in the mRNA levels of KLK7 and KLK10 between early- and advanced-stage cancers.

CONCLUSIONS

This is the first correlation of OSCC with KLK10 rs3745535G>T polymorphisms. Early-stage OSCC and high KLK7 mRNA levels were correlated with the rs10581213(wt/ins + ins/ins) genotypes. More studies with large sample sizes are needed to verify our findings.

Parallel overexpression and clinical significance of kallikrein-related peptidases 7 and 14 (KLK7KLK14) in colon cancer

Currently available colon cancer (CC) markers lack sensitivity and specificity. Kallikrein-related peptidases (KLKs) present a new class of biomarkers under investigation for diverse diseases, including cancer. KLKs are co-expressed in various tissues participating in proteolytic cascades. KLK7 in human tumours facilitates metastasis by degrading components of the extracellular matrix. KLK14 promotes tumourigenesis by activating proteinase-activated receptors. In the present study we examined the concomitant expression of KLK7 and KLK14 in245 colonic tissue specimens from 175 patients; 70 were pairs of cancerous-normal tissues, 31 were cancerous tissues and 74 were colonic adenomas. We used quantitative real-time PCR and proved that both genes are up-regulated in CC at the mRNA level. Receiver-operating characteristic (ROC) analysis of our results showed that both genes have discriminatory value between CC and adenoma tissues, with KLK14 obtaining greater distinguishing power (area under the curve [AUC]=0.708 for KLK14; AUC=0.669 for KLK7). Current work showed that the two genes are fairly co-expressed in all three types of colon tissues examined (normal rs=0.667, p<0.001, adenomas rs=0.373, p=0.001, carcinomas rs=0.478, p<0.001). KLK14 is associated with shorter disease-free survival (DFS) and overall survival (OS) of patients (p=0.003, p=0.016 respectively), whereas KLK7only with shorter DFS (p=0.004). KLK7 and KLK14 gene expression can be regarded as markers of poor prognosis for CC patients with discriminating power between CC and adenoma patients.

Kallikrein-related peptidase 4 (KLK4) mRNA predicts short-term relapse in colorectal adenocarcinoma patients

The members of the kallikrein-related peptidase (KLK) family are aberrantly expressed in cancer, including colorectal adenocarcinoma. KLK4 is an endogenous activator of protease-activated receptor 1 (PAR1) in HT-29 colorectal adenocarcinoma cells, inducing PAR1 signaling and subsequent ERK1/2 activation. The aim of this study was to analyze KLK4 mRNA expression in colorectal adenocarcinoma and to examine its prognostic value as a novel molecular tissue biomarker in this malignancy. Therefore, total RNA was isolated from primary tumors of 81 colorectal adenocarcinoma patients, cDNA was prepared, and KLK4 mRNA expression analysis was performed using quantitative real-time PCR. KLK4 mRNA was significantly associated with the Dukes stage, tumor invasion, size, and histological grade. Survival analysis demonstrated that KLK4 mRNA expression constitutes an unfavorable prognostic biomarker in colorectal adenocarcinoma, predicting poor disease-free survival (DFS), independently of the nodal status and tumor size. Furthermore, KLK4 mRNA predicts short-term relapse of lymph node-negative patients or those with tumors of early Dukes stage. In conclusion, KLK4 mRNA expression can be regarded as a novel potential tissue biomarker in colorectal adenocarcinoma.

Expression of kallikrein-related peptidase 7 predicts poor prognosis in patients with unresectable pancreatic ductal adenocarcinoma

BACKGROUND

Kallikrein-related peptidase 7 (KLK7) is overexpressed in pancreatic ductal adenocarcinomas (PDAC). The aims of this study were to examine the expression of KLK7 during progression of pancreatic intraepithelial neoplasia (PanIN) to invasive PDAC and to assess its prognostic significance for PDAC.

METHODS

Immunohistochemistry was used to assess KLK7 expression using a tissue microarray (TMA) and full sections of pancreatic tissue containing normal tissue, PanIN, and invasive adenocarcinoma, and the association between KLK7 expression and prognosis was examined by a population-based pancreatic cancer TMA.

RESULTS

Normal pancreatic epithelium was negative for KLK7 in either TMAs or full sections. Analysis by TMAs showed that 91% of cases showed KLK7 positivity in the adenocarcinoma component, which was significantly higher than PanIN 2/3. In full tissue sections of PDAC, KLK7 expression was detected in less than 1% of cells among PanIN 1A lesions, and increased with grade among PanIN 1B and PanIN2/3 lesions before reaching 69% in the invasive PDAC. In patients with unresected PDAC, KLK7 positivity was significantly associated with shorter overall survival.

CONCLUSIONS

Aberrant KLK7 expression starts in intermediate-to-late stages of PanIN progression, and KLK7-positive staining is associated with almost a three-fold increase in mortality rate of patients with unresected PDAC.

IMPACT

The association of KLK7 expression and poor outcome of patients with unresectable PDAC suggests that inhibiting either KLK7 expression and/or activity could be a therapeutic strategy. Because the vast majority of patients present with unresectable disease, such an intervention could have a significant impact upon the overall survival of this patient population.