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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., (Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

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.

Kallikrein-related peptidases (KLKs) are a group of 15 serine proteases, hormonally regulated, and localized on chromosome 19q13.4. Alternative splicing is a process that plays significant role in the development, physiology, and different diseases, like cancer. Kallikrein family numbers more than 82 alternative transcripts. Understanding the role that those gene transcripts play in various cancer types, could lead to the discovery of diagnostic markers or drug targets. The present study was designed to analyze the expression profile of the splice variants of kallikrein-related peptidase 12 (KLK12) in breast cancer patients and to evaluate their clinical significance. KLK12 splice variants (KLK12sv3 and KLK12sv1/KLK12sv2) were examined in 69 tissue samples of breast cancer using quantitative real-time PCR as well as semi-quantitative PCR. Relative quantitative expression of KLK12 was statistically associated to clinicopathological parameters. From the splice variants examined, statistical associations with clinicopathological parameters were obtained only from KLK12sv3 variant. KLK12sv3 is more frequently expressed in tumors of lower grade (p = 0.040), early patient TNM stage (p = 0.024), and smaller tumor size (p = 0.023). Positive KLK12sv3 expression is associated with longer patient disease-free survival (DFS) (p = 0.042) and higher progesterone receptor concentration (p = 0.008). KLK12sv1/KLK12sv2 expression is statistically associated with KLK12sv3 expression (p = 0.001). KLK12sv3 can be regarded as a marker of good prognosis in breast cancer.

Background: Kallikrein-related peptidases (KLKs) have been proposed as potential cancer biomarkers. Contradictions in literature led us to clarify the role of KLK5 as a breast cancer predictor, as well as its association with KLK7 expression., Patients and Methods: Semi-quantitative RT-PCR detected KLKs 5 and 7 in 80 breast tissues, 74 neoplastic and 6 normal. Steroid hormone receptors were quantified in all samples. Associations between KLK5 status and clinicopathological variables, as well as disease-free survival (DFS) and overall survival (OS) of patients were analyzed., Results: Forty tumor tissues showed high KLK5 expression, which was significantly associated with estrogen receptor status. Significant co-expression of KLKs 5 and 7 was observed in the same cancer samples (p=0.02). Increased KLK5 expression was a statistically significant independent prognostic factor for DFS (p=0.009 univariate analysis and p=0.028 multivariate analysis) and OS of patients (p=0.014, univariate analysis)., Conclusion: Increased KLK5 expression can contribute to the prognosis of DFS and OS of breast cancer patients. KLKs 5 and 7 are co-expressed in breast cancer.

Methylation of arginine residues has been implicated in many cellular activities like mRNA splicing, transcription regulation, signal transduction and protein-protein interactions. Protein arginine methyltransferases are the enzymes responsible for this modification in living cells. The most commonly used methyltransferase in man is protein arginine methyltransferase 1 (PRMT1). Since methylation processes appear to interfere in the emergence of several diseases, including cancer, we investigated the localisation of the protein in cancer tissue and, for the first time, the relation that possibly exists between the expression of PRMT1 gene and breast cancer progression. We used tumour specimens from 62 breast cancer patients and semi-quantitative RT-PCR to determine the expression of PRMT1 gene and was found to be associated with patient's age (p = 0.002), menopausal status (p = 0.006), tumour grade (p = 0.03), and progesterone receptor status (p = 0.001). Survival curves revealed that PRMT1-v1 status-low expression relates to longer disease-free survival (DFS; p = 0.036). To the contrary, PRMT1-v2 status is not associated neither with the clinical or pathological parameters nor with DFS (p = 0.31). PRMT1-v3 was not statistically significantly expressed in breast cancer tissue. Selected cancer and normal breast samples were stained for PRMT1. In both normal and cancerous breast tissues, staining was in the cytoplasm and only in rare cases the cell nucleus appeared stained. Present results show a potential use for this gene as a marker of unfavourable prognosis for breast cancer patients.

Many members of BCL2 (Bcl-2) apoptosis-related genes were found to be differentially expressed in various malignancies and were proposed as prognostic cancer biomarkers. Recently, a new member of the BCL2 gene family, BCL2L12, was cloned and was found to be expressed in mammary gland. In the present study, 55 specimens from patients with, histologically confirmed, epithelial breast carcinoma were analyzed for BCL2 and BCL2L12 gene expression by RT-PCR. Increased expression of BCL2 gene was found in patients belonging to the age groups <45 or >55 years, as well as in estrogen receptors (ER)-positive patients and in BCL2L12-positive tumors. In addition, BCL2 or BCL2L12-positive patients were found to be almost four times less likely to relapse or die in comparison to BCL2 or BCL2L12-negative patients, respectively. Multivariate analysis revealed that BCL2 and BCL2L12 might be used as independent prognostic biomarkers in breast cancer.

SR-A1 is a human high-molecular-weight SR-related CTD-associated factor that links the machineries of transcription and mRNA splicing. In this study we examined the prognostic value of SR-A1 gene expression using a semi-quantitative RT-PCR method. High SR-A1 expression was observed in 31/81 (38.3%) breast cancer tissues and was found to be more frequent in patients with tumors of large size (p=0.027), as well as in lymph node-positive patients (p=0.035). Follow-up analysis revealed that low SR-A1 expression increases the probability of both overall and disease-free survival of patients. Our results suggest that SR-A1 may possibly be characterized as a new marker of unfavorable prognosis for breast cancer.

Background: The human tissue kallikrein gene family (KLK1 to KLK15) encodes a group of 15 serine proteases (hK1 to hK15), several of which have been implicated in cancer-related processes., Methods: We established a specific quantitative reverse transcription-PCR assay for full-length KLK7 mRNA that excluded amplification of the exon 2 deletion splice variant (the latter does not encode a functional protease), and evaluated full-length KLK7 mRNA expression [normalized to human glucose-6-phosphate dehydrogenase (h-G6PDH)] in tumor tissue specimens from 155 breast cancer patients., Results: High KLK7 mRNA expression (continuous) was significantly associated with a better patient outcome according to both univariate (P = 0.005) and multivariate (P = 0.046) Cox survival analysis. Separation of patients by optimized dichotomization revealed a significantly better prognosis for patients with high KLK7 mRNA status (n = 89) compared with patients with low KLK7 mRNA status (n = 66) [univariate hazard ratio (HR) = 0.45 (P = 0.001); multivariate HR = 0.50 (P = 0.005)]. In the subgroup of patients not receiving adjuvant treatment (n = 69), KLK7 mRNA status was a significant prognosticator [univariate HR = 0.29 (P = 0.002); multivariate HR = 0.40 (P = 0.034)]. This subgroup was least influenced by postoperative treatment and thus best showed the impact of KLK7 expression on the natural course of breast cancer disease., Conclusion: Expression of full-length KLK7 mRNA may represent a new prognostic marker in breast cancer disease.

Kallikreins are a subgroup of serine proteases that are involved in the post-translational processing of polypeptide precursors. Growing evidence suggests that many kallikreins are implicated in carcinogenesis. Human kallikrein gene 7 (KLK7; HSCCE) is a new member of the human kallikrein gene family. KLK7 is expressed in normal breast tissue and is up-regulated in breast cancer cells by estrogens and glucocorticoids. In the present study, expression of the KLK7 gene in 92 breast cancer tissues was analyzed by reverse transcription-PCR (RT-PCR) and direct sequencing of several samples. The results were correlated with other clinicopathological variables and patient outcome. KLK7 gene expression was significantly lower in breast cancer patients of low stage (I/II) (p = 0.011) and patients with positive progesterone receptors (p = 0.022). Survival analysis showed that breast cancer patients with KLK7 positive tumors have relatively shorter disease-free survival (DFS) and overall survival (OS) than patients with KLK7 negative tumors. These data suggest that KLK7 gene expression may be used as a marker of unfavorable prognosis for breast cancer patients.

Apoptosis, a normal physiological form of cell death, is critically involved in the regulation of cellular homeostasis. If the delicate balance between cell death and cell proliferation is altered by a defect in the normal regulation of apoptosis signaling, a cell population is able to survive and accumulate, thereby favoring the acquisition of further genetic alterations and promoting tumorigenesis. Dysregulation of programmed cell death mechanisms plays an important role in the pathogenesis and progression of breast cancer, as well as in the responses of tumors to therapeutic intervention. Overexpression of anti-apoptotic members of the Bcl-2 family such as Bcl-2 and Bcl-XL has been implicated in cancer chemoresistance, whereas high levels of pro-apoptotic proteins such as Bax promote apoptosis and sensitize tumor cells to various anticancer therapies. Recently, a new member of the Bcl-2 family, BCL2L12, was cloned. The BCL2L12 gene is constitutively expressed in many tissues, suggesting that the encoded protein serves an important function in different cell types. In the present study, the expression of BCL2L12 gene was analyzed by reverse transcription-PCR (PT-PCR) in 70 breast cancer tissues. Our results indicate that BCL2L12 positive breast tumors are mainly of lower stage (I/II) or grade (I/II) (p=0.02 or p=0.04 respectively). Cox regression analysis revealed that BCL2L12 expression is positively related to disease-free (DFS) and overall survival (OS) at both univariate and multivariate analysis (p=0.021, p=0.029, p=0.032, p=0.044 respectively). Kaplan-Meier survival curves also demonstrated that patients with BCL2L12-positive tumors have significantly longer DFS and OS (p=0.002 and p<0.001 respectively). BCL2L12 expression may be regarded as a new independent favorable prognostic marker for breast cancer.