Prospective quantitative gene expression analysis of kallikrein-related peptidase KLK10 as a diagnostic biomarker for childhood acute lymphoblastic leukemia

Background

The most common malignancy in children is acute lymphoblastic leukemia (ALL). This study aimed to explore KLK10 mRNA expression as a potential diagnostic biomarker for ALL in children and to examine the effect of chemotherapy on KLK10 mRNA expression following the induction and after three months of receiving chemotherapy.

Methods

In this prospective study, total RNA was extracted from blood samples of 23 pediatric ALL patients on diagnosis, after one month and three months of receiving chemotherapy. Healthy pediatric volunteers (n = 12) were selected as control individuals. After cDNA synthesis, KLK10 mRNA gene expression levels were quantified using quantitative real-time PCR (qRT-PCR).

Results

KLK10 mRNA expression levels were significantly decreased in leukemic cells compared to their levels in cells of normal blood samples (p = 0.0001). KLK10 expression levels in ALL patients after one month and three months of receiving chemotherapy decreased compared to normal blood samples (p < 0.0001 and p = 0.0175 respectively). The expression level of KLK10 mRNA in ALL patients after one month of chemotherapy was decreased compared to their level on diagnosis (p = 0.4413). KLK10 mRNA expression levels in ALL patients after three months of chemotherapy were increased compared to their level on diagnosis (p = 0.0602). The ROC curve illustrated that KLK10 mRNA expression could very efficiently discriminate ALL patients from normal counterparts (AUC=0.886, 95% CI [0.7720-1.000], SE = 0.0582, p = 0.0004).

Conclusion

KLK10 mRNA expression could serve as a potential diagnostic molecular biomarker for ALL in children.

Prognostic value of kallikrein-related peptidase 7 (KLK7) mRNA expression in advanced high-grade serous ovarian cancer

BACKGROUND

High-grade serous ovarian cancer (HGSOC) is the most common and lethal subtype of ovarian cancer. A growing body of evidence suggests tumor-supporting roles of several members of the kallikrein-related peptidase (KLK) family, including KLK5 and KLK7, in this cancer subtype. In normal physiology, KLK5 and KLK7 are the major proteases involved in skin desquamation. Moreover, in several cancer types KLK5 and KLK7 co-expression has been observed. Recently, we have shown that elevated KLK5 mRNA levels are associated with an unfavorable prognosis in HGSOC. Therefore, the aim of this study was to investigate the clinical significance of KLK7 mRNA expression and to explore its relation to KLK5 levels in HGSOC.

METHODS

mRNA expression levels of KLK7 were quantified by qPCR in a well-characterized patient cohort afflicted with advanced high-grade serous ovarian cancer (FIGO III/IV, n = 139). Previously determined KLK5 mRNA as well as KLK5 and KLK7 antigen concentrations were used to evaluate the relationship between the expression patterns of both factors on the mRNA as well as protein level in tumor tissue of HGSOC patients.

RESULTS

There were strong, significant positive correlations between KLK5 and KLK7 both at the mRNA and the protein level, suggesting coordinate expression of these proteases in HGSOC. In univariate analyses, elevated KLK7 levels as well as the combination of KLK5 + KLK7 (high and/or high versus low/low) were significantly associated with worse progression-free survival (PFS). High mRNA expression levels of KLK7 and the combination of KLK5 and KLK7 showed a trend towards significance for overall survival (OS). In multivariate analyses, KLK7 mRNA expression represented an unfavorable, statistically significant independent predictor for PFS and OS.

CONCLUSIONS

The findings imply that both increased KLK5 and KLK7 mRNA expression levels represent unfavorable prognostic biomarkers in advanced high-grade serous ovarian cancer, whereby multivariate analyses indicate that KLK7 mRNA exhibits a stronger predictive value as compared to KLK5 mRNA and the combination of KLK5 and KLK7.

Beyond the biomarker role: prostate-specific antigen (PSA) in the prostate cancer microenvironment

The prostate-specific antigen (PSA) blood test is the accepted biomarker of tumor recurrence. PSA levels in serum correlate with disease progression, though its diagnostic accuracy is questionable. As a result, significant progress has been made in developing modified PSA tests such as PSA velocity, PSA density, 4Kscore, PSA glycoprofiling, Prostate Health Index, and the STHLM3 test. PSA, a serine protease, is secreted from the epithelial cells of the prostate. PSA has been suggested as a molecular target for prostate cancer therapy due to the fact that it is not only active in prostate tissue but also has a pivotal role on prostate cancer signaling pathways including proliferation, invasion, metastasis, angiogenesis, apoptosis, immune response, and tumor microenvironment regulation. Here, we summarize the current standing of PSA in prostate cancer progression as well as its utility in prostate cancer therapeutic approaches with an emphasis on the role of PSA in the tumor microenvironment.

Proteomic identification of elevated saliva kallikrein levels in the mdx-4cv mouse model of Duchenne muscular dystrophy

Dystrophinopathies are multi-system disorders that affect the skeletal musculature, the cardio-respiratory system and the central nervous system. The systematic screening of suitable biofluids for released or altered proteins promises new insights into the highly complex pathophysiology of X-linked muscular dystrophy. However, standard detection approaches using antibody-based assays often fail to reproducibly detect low-abundance protein isoforms in dilute biological fluids. In contrast, mass spectrometric screening approaches enable the proteome-wide identification of minor protein changes in biofluids. This report describes the findings from the comparative proteomic analysis of whole saliva samples from wild type versus the established mdx-4cv mouse model of highly progressive muscular dystrophy, focusing on the kallikrein protein family. Kallikrein-1 (Klk1) and 13 Klk1-related peptidases were identified in saliva and serum from normal mice. Comparative proteomics revealed elevated saliva levels of the Klk1-related peptidases Klk1-b1, Klk1-b5 and Klk-b22, as well as an increased Klk-1 concentration, which agrees with higher Klk-1 levels in serum from mdx-4cv mice. This indicates altered cellular signaling, extracellular matrix remodeling and an altered immune response in the mdx-4cv mouse, and establishes liquid biopsy procedures as suitable bioanalytical tools for the systematic survey of complex pathobiochemical changes in animal models of muscular dystrophy.

The kallikrein-related peptidase family: Dysregulation and functions during cancer progression

Cancer is the second leading cause of death with 14 million new cases and 8.2 million cancer-related deaths worldwide in 2012. Despite the progress made in cancer therapies, neoplastic diseases are still a major therapeutic challenge notably because of intra- and inter-malignant tumour heterogeneity and adaptation/escape of malignant cells to/from treatment. New targeted therapies need to be developed to improve our medical arsenal and counter-act cancer progression. Human kallikrein-related peptidases (KLKs) are secreted serine peptidases which are aberrantly expressed in many cancers and have great potential in developing targeted therapies. The potential of KLKs as cancer biomarkers is well established since the demonstration of the association between KLK3/PSA (prostate specific antigen) levels and prostate cancer progression. In addition, a constantly increasing number of in vitro and in vivo studies demonstrate the functional involvement of KLKs in cancer-related processes. These peptidases are now considered key players in the regulation of cancer cell growth, migration, invasion, chemo-resistance, and importantly, in mediating interactions between cancer cells and other cell populations found in the tumour microenvironment to facilitate cancer progression. These functional roles of KLKs in a cancer context further highlight their potential in designing new anti-cancer approaches. In this review, we comprehensively review the biochemical features of KLKs, their functional roles in carcinogenesis, followed by the latest developments and the successful utility of KLK-based therapeutics in counteracting cancer progression.

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.