Expression analysis and study of KLK4 in benign and malignant breast tumours (original) (raw)
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Tissue kallikrein-related peptidase 4 (KLK4), a novel biomarker in triple-negative breast cancer
Biological chemistry, 2017
Triple-negative breast cancer (TNBC), lacking the steroid hormone receptors ER and PR and the oncoprotein HER2, is characterized by its aggressive pattern and insensitivity to endocrine and HER2-directed therapy. Human kallikrein-related peptidases KLK1-15 provide a rich source of serine protease-type biomarkers associated with tumor growth and cancer progression for a variety of malignant diseases. In this study, recombinant KLK4 protein was generated and affinity-purified KLK4-directed polyclonal antibody pAb587 established to allow localization of KLK4 protein expression in tumor cell lines and archived formalin-fixed, paraffin-embedded TNBC tumor tissue specimens. For this, KLK4 protein expression was assessed by immunohistochemistry in primary tumor tissue sections (tissue microarrays) of 188 TNBC patients, mainly treated with anthracycline- or CMF-based polychemotherapy. KLK4 protein is localized in the cytoplasm of tumor and stroma cells. In this patient cohort, elevated stro...
Thrombosis and Haemostasis, 2003
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.
Clinical Chemistry, 2006
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 h...
Expression of human Kallikrein 14 (KLK14) in breast cancer
2006
Human kallikrein 14 (KLK14) is a steroid hormone-regulated member of the tissue kallikrein family of serine proteases, for which a prognostic and diagnostic value in breast cancer has been suggested. To further characterise the value of KLK14 as a breast tumour marker, we have carefully analysed KLK14 expression in normal breast tissue and breast cancer both on the RNA level by real-time RT-PCR (n ¼ 39), and on the protein level (n ¼ 127) using a KLK14-specific antibody for immunohistochemistry. We correlated KLK14 protein expression data with available clinico-pathological parameters (mean follow-up time was 55 months) including patient prognosis. KLK14 RNA expression as quantified by real-time RT-PCR was significantly more abundant in breast tumours compared to normal breast tissue (P ¼ 0.027), an issue that had not been clarified recently. Concordantly with the RNA data, cytoplasmic KLK14 protein expression was significantly higher in invasive breast carcinomas compared to normal breast tissues (P ¼ 0.003). Furthermore, KLK14 protein expression was associated with higher tumour grade (P ¼ 0.041) and positive nodal status (P ¼ 0.045) but was not significantly associated with shortened disease-free or overall patient survival time in univariate analyses. We conclude that KLK14 is clearly overexpressed in breast cancer in comparison to normal breast tissues and is positively associated with conventional parameters of tumour aggressiveness, but due to a missing association with survival times, the use of KLK14 immunohistochemistry as a prognostic marker in breast cancer is questionable.
British Journal of Cancer, 2002
KLK14 (formerly known as KLK-L6) is a recently identified member of the human kallikrein gene family. This family harbours several genes aberrantly expressed in various cancers as well as established (PSA/hK3, hK2) and potential (hK6, hK10) cancer markers. Similar to other kallikrein genes, KLK14 was found to be regulated by steroid hormones, particularly androgens and progestins, in breast and ovarian cancer cell lines. Preliminary studies indicated that KLK14 is differentially expressed in breast, ovarian, prostatic and testicular tumours. Given the above, we determined the prognostic significance of KLK14 expression in breast cancer. We studied KLK14 expression in 178 histologically confirmed epithelial breast carcinomas by quantitative reverse transcription-polymerase chain reaction and correlated with clinicopathological variables (tumour stage, grade, histotype etc.) and with outcome (disease-free survival and overall survival), monitored over a median of 76 months. KLK14 mRNA levels ranged from 0 to 1219 arbitrary units in breast cancer tissues, with a mean+s.e. of 136+22. An optimal cutoff value of 40.5 arbitrary units was selected, to categorise tumours as KLK14-positive or negative. Higher concentrations of KLK14 mRNA were more frequently found in patients with advanced stage (III) disease (P=0.032). No statistically significant association was found between KLK14 and the other clinicopathological variables. KLK14 overexpression was found to be a significant predictor of decreased disease-free survival (hazard ratio of 2.31, P=0.001) and overall survival (hazard ratio of 2.21, P=0.005). Cox multivariate analysis indicated that KLK14 was an independent prognostic indicator of disease-free survival and overall survival. KLK14 also has independent prognostic value in subgroups of patients with a tumour size 42 cm and positive nodal, oestrogen receptor and progestin receptor status. We conclude that KLK14 expression, as assessed by quantitative reverse transcription-polymerase chain reaction, is an independent marker of unfavourable prognosis for breast cancer.
British Journal of Cancer, 2002
Kallikreins are a group of serine proteases with diverse physiological functions. KLK13 (previously known as KLK-L4) is a novel kallikrein gene located on chromosome 19q13.4 and shares a high degree of homology with other kallikrein family members. Many kallikrein genes were found to be differentially expressed in various malignancies, and their regulation is controlled by steroid hormones in prostate and breast cancer cell lines. We studied the expression of KLK13 by quantitative reverse transcriptase-polymerase chain reaction in 173 patients with epithelial breast carcinoma. An optimal cutoff point equal to the 40th percentile was defined, based on the ability of KLK13 to predict disease-free survival. KLK13 values were then associated with other established prognostic factors and with disease-free survival and overall survival. Higher positivity for KLK13 expression was found in older, oestrogen receptor positive patients. In univariate analysis, KLK13 expression is a significant predictor of improved disease-free survival and overall survival (P50.001 and P=0.009, respectively). Cox multivariate analysis indicated that KLK13 was an independent prognostic variable in the subgroups of patients with Grade I-II tumours and in patients who were oestrogen receptor and progesterone receptor positive, and node positive. Hazard ratios derived from Cox analysis, related to disease-free survival and overall survival were 0.22 (P=0.001) and 0.24 (P=0.008), respectively, for the Grade I-II group; 0.36 (P=0.008) and 0.44 (P=0.038), respectively, for the node positive group and 0.36 (P=0.008) and 0.18 (P=0.008), respectively, for the oestrogen receptor positive group. The adjusted hazard ratio for progesterone receptor positive patients for disease-free survival was 0.25 (P=0.012). For patients in the node positive and oestrogen receptor positive subgroup (n=51) the adjusted hazard ratio was 0.25 (P=0.006) and for the node positive and progesterone receptor positive subgroup (n=46) the hazard ratio was 0.24 (P=0.008). Taken together, these data suggest that higher KLK13 expression in these subgroups of breast cancer patients is associated with an approximately 55 to 80% reduction in the risk of relapse or death. We conclude that KLK13 expression, as assessed by quantitative reverse transcriptase-polymerase chain reaction, is an independent favourable prognostic marker for breast carcinoma.
Clinical Chemistry, 2006
Background: Circulating prostate cells can be detected with a reverse transcription-PCR (RT-PCR) assay for prostate-specific antigen (PSA) mRNA. We have developed a new quantitative RT-PCR method for measuring PSA mRNA. Methods: The method uses a PSA-like internal standard (IS) mRNA that is added into the sample at the beginning of the RNA extraction and coamplified by RT-PCR with the PSA in the sample. After PCR amplification, the IS and PSA products are selectively detected by hybridization in a microtitration plate using probes labeled with fluorescent europium chelates. Results: The method was validated with PSA and IS mRNAs and PSA-expressing cells to obtain a detection limit of 50 PSA mRNA copies (i.e., signal 2 times the mean of zero signal), linearity up to 10 6 copies, and detection of a single PSA-expressing cell. In preliminary evaluations, 60% (n ؍ 10) of the prostate cancer patients with skeletal metastases gave results above the detection limit (500 PSA mRNA copies in 5 mL of blood). The total number of PSA copies ranged from 900 ؎ 200 to 44 100 ؎ 4900 (mean ؎ SD) in the samples, corresponding to ϳ1-100 PSA-expressing cells in 5 mL of blood. In the controls (n ؍ 34), none of the healthy females and 2 of 19 healthy males had detectable PSA mRNA [700 ؎ 100 and 2000 ؎ 900 (mean ؎ SD) PSA mRNA copies in 5 mL of blood for the 2 males].
Integrated genomic characterization of the kallikrein gene locus in cancer.
2012
BACKGROUND: The kallikrein-related peptidases (KLKs) have been implicated in many types of cancer, including prostate and ovarian. MATERIALS AND METHODS: We performed a comprehensive in silico study to characterize the KLK locus using transcriptomic (gene expression) and genomic (mutations and DNA copy number) data in prostate cancer (n=194), serous ovarian cancer (n=506), glioblastoma multiforme (n=206), and sarcoma (n=207) from The Cancer Genome Atlas and independent publicly available datasets to assess KLKs as cancer biomarkers. RESULTS: Overall, there was mRNA overexpression in prostate and serous ovarian cancer and decreased expression in glioblastoma multiforme. There was higher frequency of genomic loss in serous ovarian cancer, and rare KLK gene mutations observed in serous ovarian cancer and GBM. Dysregulation of KLKs correlates with survival: for prostate cancer, a combination of dysregulation of KLK1, 5 and 13 was associated with worse disease-free survival. CONCLUSION: We conclude that specific dysregulation of KLKs at the genetic and transcriptomic levels have useful prognostic value.
Human kallikrein 4 (KLK4) is highly expressed in serous ovarian carcinomas
Clinical cancer research : an official journal of the American Association for Cancer Research, 2001
Previous studies indicated that a new member of the human kallikrein (KLK) gene family, KLK4, was expressed in prostate, breast, and endometrial carcinoma cell lines and may have potential as a tumor marker. The aim of this study was to examine the expression of KLK4 in the normal ovary and ovarian tumors of different histology, stage, and differentiation and to determine its association with ovarian tumor progression. Using reverse transcription-PCR, Southern blot, and densitometry analyses, we found the level of KLK4 expression was higher in late stage serous (SER) epithelial-derived ovarian carcinomas than in normal ovaries, mucinous epithelial tumors, and granulosa cell tumors. KLK4 was highly expressed in all of the SER ovarian carcinoma cell lines (eight of eight), SER epithelial carcinomas (11 of 11), and two adenomas, whereas it was expressed at a lower level (or not at all) in normal ovaries (four of six), mucinous epithelial tumors (three of four), endometrioid carcinomas ...
Higher human kallikrein gene 4 (KLK4) expression indicates poor prognosis of ovarian cancer patients
Clinical cancer research : an official journal of the American Association for Cancer Research, 2001
Kallikrein gene 4 (KLK4, also known as prostase/KLK-L1), located on chromosome 19q13.4, is one of the newly discovered members of the human KLK-like gene family. This gene is up-regulated by androgens in the LNCaP prostatic carcinoma cell line and by androgens and progestins in the BT-474 breast cancer cell line. On the basis of its apparent association with hormonally regulated tissues, we have undertaken to examine the prognostic value of KLK4 expression in 147 malignant ovarian tissues. Tumors were pulverized, total RNA was extracted, and cDNA was prepared by reverse transcription. KLK4 was amplified by PCR using gene-specific primers, and its identity was verified by sequencing. Ovarian tissues were then classified as KLK4-positive or -negative, based on ethidium bromide visualization of the PCR product on agarose gels. KLK4 was found to be expressed in 69 (55%) of 147 of ovarian cancer samples. We found a strong positive association between KLK4 expression and tumor grade (P = ...