Tumor-targeting albumin nanoparticles as an efficacious drug delivery system and potential diagnostic tool in non-muscle-invasive bladder cancer therapy

Current intravesical chemotherapy for non-muscle invasive bladder cancer (NMIBC) has limited efficacy due to loss of the instilled agent from urine voiding and the agent's lack of specificity for the tumors. We developed a nanocarrier (txCD47-HNP, ∼100 nm) based on human serum albumin conjugated with a peptide that targets the cluster of differentiation 47 receptor overexpressed on bladder cancer (BC) cells. The IC₅₀ of gemcitabine elaidate (GEM) loaded in the txCD47-HNP was almost an order of magnitude lower than that of free GEM. In a mouse orthotopic BC model, GEM loaded in txCD47-HNP effectively reduced the tumor burden. Tumor cells in BC patients' urine can also be targeted by fluorescence-labeled txCD47-HNP resulting in >83 % of the cells exhibiting fluorescence. Thus, txCD47-HNP can potentially be a theranostic agent in NMIBC management by serving as a targeted drug delivery vehicle as well as an alternative to urine cytology.

Integrated Transcriptome Analysis Reveals KLK5 and L1CAM Predict Response to Anlotinib in NSCLC at 3rd Line

The oral multi-targeted tyrosine kinase inhibitor (TKI) anlotinib is effective for non-small cell lung cancer (NSCLC) in clinical trials at 3rd line. However, a fraction of patients remains non-responsive, raising the need of how to identify anlotinib-responsive patients. In the present study, we aimed to screen potential biomarkers for anlotinib-responsive stratification via integrated transcriptome analysis. Comparing with the anlotinib-sensitive lung cancer cell NCI-H1975, we found 1,315 genes were differentially expressed in anlotinib-resistant NCI-H1975 cells. Among the enriched angiogenesis-related genes, we observed high expression of KLK5 and L1CAM was mostly associated with poor clinical outcomes in NSCLC patients through Kaplan-Meier survival analysis in a TCGA cohort. Moreover, an independent validation in a cohort of ALTER0303 (NCT02388919) indicated that high serum levels of KLK5 and L1CAM were also associated with poor anlotinib response in NSCLC patients at 3rd line. Lastly, we demonstrated that knockdown of KLK5 and L1CAM increases anlotinib-induced cytotoxicity in anlotinib-resistant NCI-H1975 cells. Collectively, our study suggested serum levels of KLK5 and L1CAM potentially serve as biomarkers for anlotinib-responsive stratification in NSCLC patients at 3rd line.

A Novel Flavonoid Composition Targets Androgen Receptor Signaling and Inhibits Prostate Cancer Growth in Preclinical Models

The high prevalence and long latency period of prostate cancer (PCa) provide a unique opportunity to control disease progression with dietary and nutraceutical approaches. We developed ProFine, a standardized composition of luteolin, quercetin, and kaempferol, and investigated its potential as a nutraceutical for PCa in preclinical models. The three ingredients of ProFine demonstrated synergistic in vitro cytotoxicity and effectively induced apoptosis in PCa cells. ProFine markedly affected the transcriptome of PCa cells, suppressed the expression of androgen receptor, and inhibited androgen-regulated genes. Oral administration of ProFine did not exhibit obvious toxicities in mice, and the three ingredients retained their individual pharmacokinetic and bioavailability profiles. Importantly, ProFine significantly retarded the growth of PCa xenografts in athymic nude mice and extended the survival of animals. This study provides preclinical evidence supporting the promise of ProFine as a safe, efficacious, and affordable intervention to control PCa progression and improve clinical outcomes.

Kallikrein-related peptidases targeted therapies in prostate cancer: perspectives and challenges

INTRODUCTION

Despite the emergence of several new effective treatments for metastatic castration-resistant prostate cancer patients, disease progression inevitably occurs, leading scientific community to carefully look for novel therapeutic targets of prostate cancer. Kallikrein (KLK)-related peptidases have been demonstrated to facilitate prostate tumorigenesis and disease progression through the development of an oncogenic microenvironment for prostate cells.

AREAS COVERED

This review first summarizes the large amount of preclinical data showing the involvement of KLKs in prostate cancer pathobiology. In the second part, the authors assess the current status and future directions for KLK-targeted therapy and briefly describe the advances and challenges implicated in the design of effective manufactured drugs. The authors then focus on the preclinical data and on Phase I/II studies of the most promising KLK-targeted agents in prostate cancer. The drugs discussed here are divided on the basis of their mechanism of action: KLK-engineered inhibitors; KLK-activated pro-drugs; KLK-targeted microRNAs and small interfering RNAs(-/)small hairpin RNAs; KLK vaccines and antibodies.

EXPERT OPINION

Targeting KLK expression and/or activity could be a promising direction in prostate cancer treatment. Future human clinical trials will help us to evaluate the real benefits, toxicities and the consequent optimal use of KLK-targeted drugs, as mono-therapy or in combination regimens.

Kallikrein-related peptidase 13: an independent indicator of favorable prognosis for patients with nonsmall cell lung cancer

The KLK13 gene is dysregulated in several carcinomas, and its expression levels seem to be associated with disease prognosis. The aim of our study was to investigate the prognostic potential of KLK13 mRNA expression for patients with nonsmall cell lung cancer (NSCLC). Total RNA was isolated from cancerous and normal tissues from a cohort of 128 NSCLC patients. The KLK13 mRNA transcription levels were measured using a sensitive quantitative RT-PCR method. The results were normalized by dividing the KLK13 mRNA values with the geometric mean of mRNA expression from four reference genes: beta-actin, TATA-binding protein, hypoxanthine phosphoribosyltransferase 1, and acidic ribosomal phosphoprotein P0. The malignant tissues from the majority of patients (59.3 %) contained significantly more KLK13 mRNA transcripts than did the paired nonmalignant tissues (median difference 11.1-fold, P = 0.008). KLK13 was expressed at higher levels in females than that in males (P = 0.021). No other statistically significant association with clinicopathological data was observed. Kaplan-Meier survival analyses demonstrated that patients with KLK13-positive tumors survived significantly longer than those with KLK13-negative ones (P = 0.009). KLK13 expression was also shown to be able to stratify high-risk individuals among patients with early disease stages (P = 0.030). Multivariate Cox regression analysis showed that KLK13 expression is a favorable, independent prognostic indicator of overall survival (OS) (P = 0.024). Our results suggest that KLK13 mRNA expression constitutes a novel biomarker for the prediction of overall survival in NSCLC and that its quantitative assessment in tumor tissues can aid in treatment decision making.

Kallikreins as biomarkers for prostate cancer

The introduction of testing for prostate-specific antigen (PSA), a member of the fifteen-gene family of kallikrein-related peptidases and also known as kallikrein-related peptidase 3 (KLK3), in blood has revolutionized both the detection and management of prostate cancer. Given the similarities between PSA and other KLK gene family members along with limitations of PSA as a biomarker for prostate cancer mainly in reference to diagnostic specificity, the potential roles of other members of this gene family as well as PSA derivatives and isoforms in the management of prostate cancer have been studied extensively. Of these, approaches to measure distinct molecular forms of PSA (free, intact, complexed PSA, and pro-PSA) combined with kallikrein-related peptidase 2 (KLK2), also known as hK2, have been considered holding particular promise in enhancing the diagnosis of prostate cancer. Recently, an integrated approach of applying a panel of four kallikrein markers has been demonstrated to enhance accuracy in predicting the risk of prostate cancer at biopsy. This review presents an overview of kallikreins, starting with the past and current status of PSA, summarizing published data on the evaluations of various KLKs as biomarkers in the diagnosis, prognostication, and monitoring of prostate cancer.

Prostate cancer biomarkers: an update

Many aspects of prostate cancer diagnosis and treatment could be greatly advanced with new, effective biomarkers. Prostate-specific antigen (PSA) has multiple weaknesses as a biomarker, such as not distinguishing well between cancer and benign prostatic hyperplasia or between indolent and aggressive cancers, thus leading to overtreatment, especially unnecessary biopsies. PSA also often fails to indicate accurately which patients are responding to a given treatment. Yet PSA is the only prostate cancer biomarker routinely used by urologists. Here, we provide updated information on the most relevant of the other biomarkers currently in use or in development for prostate cancer. Recent research shows improvement over using PSA alone by comparing total PSA (tPSA) or free PSA (fPSA) with new, related markers, such as prostate cancer antigen (PCA) 3, the individual molecular forms of PSA (proPSA, benign PSA, and intact PSA), and kallikreins other than PSA. Promising results have also been seen with the use of the fusion gene TMPRSS2:ERG and with various forms of the urokinase plasminogen activation receptor. Initially, there were high hopes for early PCA, but those data were not reproducible and thus research on early PCA has been abandoned. Much work remains to be done before any of these biomarkers are fully validated and accepted. Currently, the only markers discussed in this paper with Food and Drug Administration-approved tests are PCA 3 and an isoform of proPSA, [-2]proPSA. Assays are in development for most of the other biomarkers described in this paper. While the biomarker validation process can be long and filled with obstacles, the rewards will be great-in terms of both patient care and costs to the health care system.

Quantified KLK15 gene expression levels discriminate prostate cancer from benign tumors and constitute a novel independent predictor of disease progression

BACKGROUND

Several transcript variants of the kallikrein-related peptidase 15 gene (KLK15) have been identified up to now. The classical KLK15 mRNA isoform encodes for a non-truncated, functional protein. Aberrant KLK15 expression is found in breast, ovarian, and prostate cancers. Our aim in this present study was the specific quantitative expression analysis of the classical KLK15 mRNA transcript in prostate tumors and the examination of its clinical significance in prostate cancer.

METHODS

We isolated total RNA from 150 prostate tissue specimens and, following cDNA synthesis, the expression of KLK15 classical mRNA transcript was measured via quantitative Real-Time PCR using the TaqMan® chemistry. HPRT1 was used as a reference gene, and the absolute quantification approach, through the incorporation of standard curves, was applied for the calculation of normalized KLK15 expression.

RESULTS

KLK15 expression levels were significantly upregulated in malignant compared to benign samples (P < 0.001). The discriminatory value of KLK15 was confirmed by ROC curve and logistic regression analysis (both P < 0.001). KLK15 was also associated with advanced pathological stage (P = 0.023). KLK15-positive prostate cancer patients presented significantly shorter progression-free survival intervals, determined by biochemical relapse (P = 0.006), compared to KLK15-negative ones. Multivariate Cox regression analysis revealed that KLK15 expression is an independent predictor of biochemical recurrence (HR = 3.36, P = 0.038).

CONCLUSIONS

The present study unravels the important role of quantified KLK15 classical mRNA expression levels as a novel biomarker helpful for the differential diagnosis and prognosis of prostate cancer patients.

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.

Kallikrein-related peptidase 4 gene (KLK4) in prostate tumors: quantitative expression analysis and evaluation of its clinical significance

BACKGROUND

Recently accumulating evidences underline the central role of the kallikrein-related peptidases family (KLKs) in prostate cancer (PCa) development and progression. The KLK4 is a prostate highly expressed gene under the transcriptional control of androgens, encoding for the KLK4 extracellular serine protease. The aim of this study is to investigate the expression status of KLK4 in PCa patients in order to reveal its utility in PCa establishment and clinical management.

METHODS

Prostatic tissue specimens were obtained from 60 PCa and 59 benign prostate hyperplasia (BPH) randomly chosen patients. Using a developed quantitative real-time RT-PCR method, KLK4 expression levels were determined in the specimens of the two patients' cohorts. Advance biostatistical analysis was completed to explore the clinical value of KLK4 expression in PCa and BPH patients.

RESULTS

PCa patients presented a statistically significant (P = 0.002) elevation, more than threefold, of the KLK4 transcripts compared to BPH ones. The KLK4 expression levels were also positive correlated with PCa patients' stage (P = 0.031) and preoperative prostate-specific antigen (PSA) serum concentrations (P < 0.001). ROC curve and logistic regression analysis revealed the significant (P = 0.002) and the independent (P = 0.044) clinical value of the KLK4 expression for the discrimination of PCa from BPH patients.

CONCLUSIONS

The KLK4 expression analysis reveals its up-regulation in PCa cells, which is significantly associated with the advanced stages of the disease and the patients' preoperative PSA serum levels. KLK4 quantification serves as an independent biomarker for the discrimination between the malignant and the benign nature of prostate tumors.

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

Background

Kallikrein-related peptidase 5 (KLK5) is a secreted trypsin-like protease of the KLK family, encoded by the KLK5 gene. KLK5 has been found to cleave various extracellular matrix components, as well as to activate several other KLK proteases, triggering the stimulation of tissue microenvironment proteolytic cascades.

Material and Methods

KLK5 expression levels were quantified in 102 cancerous and benign breast tissue specimens, obtained by randomly chosen patients, using RT-qPCR assay. Subsequently, advanced biostatistics were applied in order to analyze the KLK5 expression profile in the two patients' cohorts and also to evaluate its clinical significance for the discrimination of breast tumors.

Results

A statistically significant (p < 0.001) down-regulation of the KLK5 expression levels were observed in the malignant specimens compared to the benign ones. Logistic regression and ROC curve analysis revealed the significant (p < 0.001) and the independent (p < 0.001) value of the KLK5 expression quantification, for the discrimination of the malignant from the benign mammary gland biopsies. Moreover, KLK5 expression levels correlate with the pre-menopausal status (p < 0.005) as well as the ER-negative staining (p = 0.028) of women with breast cancer.

Conclusions

The quantification of KLK5 expression in breast tissue biopsies may be considered as a novel and independent biomarker for the differential diagnosis between malignant and benign tumors of the mammary gland.

Kallikrein-related peptidase genes as promising biomarkers for prognosis and monitoring of human malignancies

Tissue kallikrein (KLK1) and the kallikrein-related peptidase (KLK2-15) genes encode for a subgroup of 15 homologous secreted serine proteases possessing numerous physiological roles, such as the regulation of blood pressure, hormone processing and tissue remodeling. The expression of KLKs is detected in a broad spectrum of human tissues where it has been found to be regulated mainly by steroids hormones. The aberrant expression of KLKs, presented in many human malignancies, highlights the significance of this gene family for early diagnosis, prognosis and monitoring of cancer patients, as it is strongly emphasized by the routine use of PSA (KLK3) for prostate cancer management. Here, we review the presently known data regarding the role of KLKs as cancer biomarkers, giving emphasis on novel information about the subject.