Kallikrein-related Peptidase Research Articles

Kallikrein-related peptidases: mechanistic understanding for potential therapeutic targeting in cancer.

Human kallikrein-related peptidases (KLKs) represent a subgroup of 15 serine endopeptidases involved in various physiological processes and pathologies, including cancer. This review aims to provide a comprehensive overview of the KLK family, highlighting their genomic structure, expression profiles and substrate specificity. We explore the role of KLKs in tumorigenesis, emphasizing their potential as biomarkers and therapeutic targets in cancer treatment. The dysregulated activity of KLKs has been linked to various malignancies, making them promising candidates for cancer diagnostics and therapy. : Recent advancements in understanding the mechanistic pathways of KLK-related tumorigenesis offer new prospects for developing targeted cancer treatments. Expert opinion suggests that while significant progress has been made, further research is necessary to fully exploit KLKs' potential in clinical applications.

Liquid-liquid phase separation-related genes associated with prognosis, tumor microenvironment characteristics, and tumor cell features in bladder cancer.

This study aimed to explore the Liquid-liquid phase separation (LLPS)-related genes associated with the prognosis of bladder cancer (BCa) and assess the potential application of LLPS-related prognostic signature for predicting prognosis in BCa patients. Clinical information and transcriptome data of BCa patients were extracted from the Cancer Genome Atlas-BLCA (TCGA-BLCA) database and the GSE13507 database. Furthermore, 108 BCa patients who received treatment at our institution were subjected to a retrospective analysis. The least absolute shrinkage and selection operator (LASSO) analysis was performed to develop an LLPS-related prognostic signature for BCa. The CCK8, wound healing and Transwell assays were performed. Based on 62 differentially expressed LLPS-related genes (DELRGs), three DELRGs were screened by LASSO analysis including kallikrein-related peptidase 5 (KLK5), monoacylglycerol O-acyltransferase 2 (MOGAT2) and S100 calcium-binding protein A7 (S100A7). Based on three DELRGs, a novel LLPS-related prognostic signature was constructed for individualized prognosis assessment. Kaplan-Meier curve analyses showed that LLPS-related prognostic signature was significantly correlated with overall survival (OS) of BCa. ROC analyses demonstrated the LLPS-related prognostic signature performed well in predicting the prognosis of BCa patients in the training group (the area under the curve (AUC) = 0.733), which was externally verified in the validation cohort 1 (AUC = 0.794) and validation cohort 2 (AUC = 0.766). Further experiments demonstrated that inhibiting KLK5 could affect the proliferation, migration, and invasion of BCa cells. In this study, a novel LLPS-related prognostic signature was successfully developed and validated, demonstrating strong performance in predicting the prognosis of BCa patients.

Developmental Therapeutics in Metastatic Prostate Cancer: New Targets and New Strategies.

There is an unmet need to develop new treatments for metastatic prostate cancer. With the development of targeted radioligand therapies, bispecific T cell engagers, antibody-drug conjugates and chimeric antigen receptor T cell (CAR T) therapies, tumor-associated cell surface antigens have emerged as new therapeutic targets in metastatic prostate cancer. Ongoing and completed clinical trials targeting prostate-specific membrane antigen (PSMA), six transmembrane epithelial antigens of the prostate 1 (STEAP1), kallikrein-related peptidase 2 (KLK2), prostate stem cell antigen (PSCA), and delta-like protein 3 (DLL3) in metastatic prostate cancer were reviewed. Strategies for sequential or combinational therapy were discussed.

Hypoxic Regulation of the KLK4 Gene in two Different Prostate Cancer Cells Treated with TGF- β.

The human kallikrein-related peptidase (KLK) family which consists of 15 members is associated with prostate cancer and other cancers. It has been reported that overexpression of KLK4 in prostate cancer correlates with bone metastasis or advanced stage. Hypoxia occurs in the early stages of prostate cancer due to the accumulation of acidic metabolites or reactive oxygen species (ROS). In our study, KLK4 gene expression in hypoxic conditions in PC-3 and LNCaP cells which are treated with TGF-β was evaluated with mRNA, protein, and promoter activity levels. A chemical hypoxia model was created and confirmed at mRNA and protein level. No statistically significant cytotoxic effect of CoCl2 and TGF-β was observed in PC-3 and LNCaP cells with the MTT test. Four different truncated KLK4 gene promoter constructs were cloned in pmetLuc expression vector and basal activities of all promoter fragments were analyzed. The activities of P1 (-447/ + 657), P2 (-103/ + 657), and P3 (-267/ + 657) promoter fragments increased in hypoxic conditions except P4 (+555/ + 657), which does not contain the SMAD and HRE region. KLK4 mRNA levels in both PC-3 and LNCaP cells increased in the hypoxia and hypoxia/TGF groups compared to the non-treated groups. The stimulating effect of TGF-β is correlated with the increase in SMAD2/3 mRNA levels. KLK4 expression is up-regulated by TGF-β, especially under hypoxic conditions, and its interaction with the SMAD pathway is determined with different inhibitor experiments. HIF-1α and SMAD transcription factors bind to the KLK4 promoter showing the direct interaction of HIF-1α (-80/-52) and SMAD (+163/+194) regions with EMSA.

Extracellular Domain of IL-10 Receptor Chain-2 (IL-10R2) and Its Arginine-Containing Peptides Are Susceptible Substrates for Human Prostate Kallikrein-2 (KLK2).

The kallikrein-related peptidase KLK2 has restricted expression in the prostate luminal epithelium, and its protein target is unknown. The present work reports the hydrolytic activities of KLK2 on libraries of fluorescence resonance energy-transfer peptides from which the sequence SYRIF was the most susceptible substrate for KLK2. The sequence SYRIF is present at the extracellular N-terminal segment (58SYRIF63Q) of IL-10R2. KLK2 was fully active at pH 8.0-8.2, found only in prostate inflammatory conditions, and strongly activated by sodium citrate and glycosaminoglycans, the quantities and structures controlled by prostate cells. Bone-marrow-derived macrophages (BMDM) have IL-10R2 expressed on the cell surface, which is significantly reduced after KLK2 treatment, as determined by flow cytometry (FACS analysis). The IL-10 inhibition of the inflammatory response to LPS/IFN-γ in BMDM cells due to decreased nitric oxide, TNF-α, and IL-12 p40 levels is significantly reduced upon treatment of these cells with KLK2. Similar experiments with KLK3 did not show these effects. These observations indicate that KLK2 proteolytic activity plays a role in prostate inflammation and makes KLK2 a promising target for prostatitis treatment.

Recombinant scFv-Fc Anti-kallikrein 7 Antibody-Loaded Thermosensitive Hydrogels Against Skin Desquamation Disorders.

Human tissue kallikrein-related peptidase 7 (KLK7) is a serine protease implicated in the physiology of skin desquamation, and its uncontrolled activity can lead to chronic diseases such as psoriasis, atopic dermatitis, and Netherton syndrome. For this reason, kallikrein 7 has been identified as a potential therapeutic target. This work aimed to evaluate Pluronic (PL) hydrogels as topical carriers of four specific scFv-Fc antibodies to inhibit KLK7. The hydrogels comprised PL F127 (30% w/v) alone and a binary F127/P123 (28-2% w/v) system. Each formulation was loaded with 1 μg/mL of each antibody and characterized by physicochemical and pharmaceutical techniques, considering antibody-micelle interactions and hydrogel behavior as smart delivery systems. Results showed that the antibodies were successfully loaded into the PL-based systems, and the sol-gel transition temperature was shifted to high values after the P123 addition. The antibodies released from the gels preserved their rheological properties (G' > G'', 35- to 41-fold) and inhibitory activity against KLK7, even after 24 h. This work presented potential agents targeting KLK7 that may provide strategies for treating skin abnormalities.

MicroRNA-141-regulated KLK10 and TNFSF-15 gene expression in hepatoblastoma cells as a novel mechanism in liver carcinogenesis

Liver cancer is one of the most pivotal global health problems, leading hepatocellular carcinoma (HCC) with a significant increase in cases worldwide. The role of non-coding-RNA in cancer proliferation and carcinogenesis has attracted much attention in the last decade; however, microRNAs (miRNAs), as non-coding RNA, are considered master mediators in various cancer progressions. Yet the role of miR-141 as a modulator for specific cellular processes in liver cancer cell proliferation is still unclear. This study identified the role of miR-141 and its potential functions in liver carcinogenesis. The level of miR-141 in HepG2 and HuH7 cells was assessed using quantitative real-time PCR (qRT-PCR) and compared with its expression in normal hepatocytes. A new miR-141 construct has been performed in a CMV promoter vector tagged with GFP. Using microarray analysis, we identified the potentially regulated genes by miR-141 in transfected HepG2 cells. The protein profile of the kallikrein-related peptidase 10 (KLK10) and tumor necrosis factor TNFSF-15 was investigated in HepG2 cells transfected with either an inhibitor, antagonist miR-141, or miR-141 overexpression vector using immunoblotting and flow cytometry assay. Finally, ELISA assay has been used to monitor the produced inflammatory cytokines from transfected HepG2 cells. Our findings showed that the expression of miR-141 significantly increased in HepG2 and HuH7 cells compared to the normal hepatocytes. Transfection of HepG2 cells with an inhibitor, antagonist miR-141, showed a significant reduction of HepG2 cell viability, unlike the transfection of miR-141 overexpression vector. The microarray data of HepG2 cells overexpressed miR-141 provided a hundred downregulated genes, including KLK10 and TNFSF-15. Furthermore, the expression profile of KLK10 and TNFSF-15 markedly depleted in HepG2 cells transfected with miR-141 overexpression accompanied by a decreasing level of interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α), indicating the role of miR-141 in HepG2 cell proliferation and programmed cell death. Interestingly, the experimental rats with liver cancer induced by Diethylnitrosamine injection further confirmed the upregulation of miR-141 level, IL-10, and TNF-α and the disturbance in KLK10 and TNFSF-15 gene expression compared with their expression in normal rats. The in-silico online tools, IntaRNA and miRWalk were used to confirm the direct interaction and potential binding sites between miR-141 and identified genes. Thus, the seeding regions of potential targeted sequences was cloned upstream of luciferase reporter gene in pGL3 control vector. Interestingly, the luciferase activities of constructed vectors were significantly decreased in HepG2 cells pre-transfected with miR-141 overexpression vector, while increasing in cells pre-transfected with miR-141 specific inhibitor. In summary, these data suggest the crucial role of miR-141 in liver cancer development via targeting KLK10 and TNFSF-15 and provide miR-141 as an attractive candidate in liver cancer treatment and protection.

Identification of CSNK1D and KLK6 as two common upregulated genes present in BRCA1 mutated triple-negative breast cancer and ovarian epithelial carcinoma

Deficiency in the breast cancer type 1 (BRCA1) gene expression predisposes to triple-negative breast cancer (TNBC) and ovarian cancer (OC). We previously identified by Comparative Genomic Hybridization (CGH) array a gain in the 17q25.3 genomic region in 90% of the BRCA1 mutated TNBC tissues, where 17 genes were up-regulated. A second region (Chr19_45681759_54221324) was identified as the second most frequent gain in the BRCA1-mutated population and has not yet been described in the context of BRCA1 mutation. We thus aimed to validate the expression of the Casein kinase 1 delta (CSNK1D) gene of Chr17 in TNBC and OC cell lines and to investigate the expression of genes of Chr19 in TNBC cell lines and tissues as well as in OC cell lines. Expression level of the genes of the 17q25.3, 19q13.32,13.33 and 13.41 chromosomal regions was analyzed using RT-PCR in BRCA1 deficient TNBC and OC cell lines, as well as in 10 BRCA1-mutated TNBC tissues versus 10 wild type carriers. Our results revealed a significant upregulation of CSNK1D gene expression in BRCA1 deficient TNBC and OC cell lines when compared to control ones, and a significant aberration in the expression of the other six genes of Chr19 was observed. Interestingly, upregulation of kallikrein-related peptidase 6 (KLK6) was detected among the BRCA1 deficient TNBC (cell lines and tissues) and OC cell lines. In conclusion, our results suggested that CSNK1D and KLK6 expression levels could be very promising in the search for biomarkers for BRCA1 deficient TNBC and OC.

Three stepwise pH progressions in stratum corneum for homeostatic maintenance of the skin

The stratum corneum is the outermost skin layer with a vital role in skin barrier function. It is comprised of dead keratinocytes (corneocytes) and is known to maintain its thickness by shedding cells, although, the precise mechanisms that safeguard stratum corneum maturation and homeostasis remain unclear. Previous ex vivo studies have suggested a neutral-to-acidic pH gradient in the stratum corneum. Here, we use intravital pH imaging at single-corneocyte resolution to demonstrate that corneocytes actually undergo differentiation to develop three distinct zones in the stratum corneum, each with a distinct pH value. We identified a moderately acidic lower, an acidic middle, and a pH-neutral upper layer in the stratum corneum, with tight junctions playing a key role in their development. The upper pH neutral zone can adjust its pH according to the external environment and has a neutral pH under steady-state conditions owing to the influence of skin microbiota. The middle acidic pH zone provides a defensive barrier against pathogens. With mathematical modeling, we demonstrate the controlled protease activation of kallikrein-related peptidases on the stratum corneum surface that results in proper corneocyte shedding in desquamation. This work adds crucial information to our understanding of how stratum corneum homeostasis is maintained.

Higher Expression of Lympho-epithelial Kazal-type-Related Inhibitor-1 Fragments and Decreased Desquamation in the Lesional Skin of Nummular Eczema.

Nummular eczema, a chronic dermatitis characterized by coin-shaped lesions, was first documented in 1857. However, its pathophysiological characteristics are still not well known. To investigate differences in the regulation of the desquamation process in the stratum corneum of lesional and nonlesional skin of patients with nummular eczema and healthy control subjects, tape-stripped stratum corneum samples from patients with nummular eczema and healthy volunteers were analysed using immunofluorescence staining and western blot analysis. In the nummular eczema lesional skin, expression of desmoglein-1, desmocollin-1, and corneodesmosin exhibited a disorganized, dense or partially diffuse non-peripheral pattern with increased intensity, compared with the peripheral patterns observed in healthy or nonlesional skin, suggesting the impaired desquamation process in nummular eczema. Furthermore, although the expression of the desquamation-related serine proteases, kallikrein-related peptidase 7 and 5, was increased in nummular eczema lesional skin, the immunofluorescence staining of lympho-epithelial Kazal-type-related inhibitor-1, an endogenous inhibitor of various kallikrein-related peptidases, and its fragments were significantly increased in the nummular eczema lesional skin, suggesting its contribution to the inhibition of corneodesmosomal degradation. Therefore, the increased detection of corneodesmosomal proteins in nummular eczema lesions may be due to the increased amount of the fragments of lympho-epithelial Kazal-type-related inhibitor-1, which could contribute to delayed desquamation.

Triterpenoid ursolic acid regulates the environmental carcinogen benzo[a]pyrene-driven epigenetic and metabolic alterations in SKH-1 hairless mice for skin cancer interception.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental carcinogens accountable to developing skin cancers. Recently, we reported that exposure to benzo[a]pyrene (B[a]P), a common PAH, causes epigenetic and metabolic alterations in the initiation, promotion and progression of non-melanoma skin cancer (NMSC). As a follow-up investigation, this study examines how dietary triterpenoid ursolic acid (UA) regulates B[a]P-driven epigenetic and metabolic pathways in SKH-1 hairless mice. Our results show UA intercepts against B[a]P-induced tumorigenesis at different stages of NMSC. Epigenomic cytosines followed by guanine residues (CpG) methyl-seq data showed UA diminished B[a]P-mediated differentially methylated regions (DMRs) profiles. Transcriptomic RNA-seq revealed UA revoked B[a]P-induced differentially expressed genes (DEGs) of skin cancer-related genes, such as leucine-rich repeat LGI family member 2 (Lgi2) and kallikrein-related peptidase 13 (Klk13), indicating UA plays a vital role in B[a]P-mediated gene regulation and its potential consequences in NMSC interception. Association analysis of DEGs and DMRs found that the mRNA expression of KLK13 gene was correlated with the promoter CpG methylation status in the early-stage comparison group, indicating UA could regulate the KLK13 by modulating its promoter methylation at an early stage of NMSC. The metabolomic study showed UA alters B[a]P-regulated cancer-associated metabolisms like thiamin metabolism, ascorbate and aldarate metabolism during the initiation phase; pyruvate, citrate and thiamin metabolism during the promotion phase; and beta-alanine and pathothenate coenzyme A (CoA) biosynthesis during the late progression phase. Taken together, UA reverses B[a]P-driven epigenetic, transcriptomic and metabolic reprogramming, potentially contributing to the overall cancer interception against B[a]P-mediated NMSC.

Modeling of new markers for the diagnosis and prognosis of pancreatic cancer based on the transition from inflammation to cancer.

Pancreatic adenocarcinoma (PAAD) is a lethal disease with a poor prognosis. Genes involved in acute pancreatitis (AP) or chronic pancreatitis (CP) might be important for PAAD development. This study sought to identify potential PAAD diagnosis markers and to establish a PAAD prognosis prediction model based on AP- and CP-related genes. The significantly differentially expressed genes in both AP or CP and PAAD were obtained by a bioinformatics analysis. A risk-score model for predicting survival was constructed based on The Cancer Genome Atlas (TCGA) data and validated using an International Cancer Genome Consortium (ICGC) cohort. Protein expression and the effects of the genes in the risk models were validated by immunohistochemistry, or Cell Counting Kit-8 (CCK-8) and transwell assays. The study sample data included six AP tissue samples and five normal pancreatic tissue samples, six CP tissue samples and six normal pancreatic tissue samples from the Gene Expression Omnibus (GEO) expression profiling microarrays GSE109227 and GSE41418 data sets, respectively, and fragments per kilobase per million mapped fragments (FPKM) data from four normal controls and 150 PAAD cases from TCGA database, and 182 cancer patient samples with complete survival prognostic data from the ICGC database. In total, 508 significantly differentially expressed genes were found in both AP or CP and PAAD. Trefoil factor 2 (TFF2), tubulointerstitial nephritis antigen (TINAG), trefoil factor 1 (TFF1), aquaporin 5 (AQP5), SAM pointed domain containing ETS transcription factor (SPDEF), anterior gradient protein 2 (AGR2), apolipoprotein B messenger RNA editing enzyme catalytic subunit 1 (APOBEC1), kallikrein-related peptidase 6 (KLK6), dopa decarboxylase (DDC), mucin 13 (MUC13), claudin 18 (CLDN18), annexin A10 (ANXA10), and tetraspanin 1 (TSPAN1) were found to be present in PAAD and had the largest fold change. A risk-score model, comprising 19 genes, was constructed for prognostic prediction. A high-risk score indicated a poor prognosis. TINAG, DDC, SPDEF, and APOBEC1 proteins were increased in PAAD, while TINAG and DDC were correlated with the pathologic grade. Decreased TINAG, APOBEC1, transmembrane protein 94 (TMEM94), and kelch like family member 36 (KLHL36) expression inhibited PAAD cell proliferation, while decreased SPDEF, TMEM94, and KLHL36 expression significantly inhibited PAAD cell migration. The AP and CP co-related genes were significantly correlated with PAAD. TINAG, DDC, SPDEF, and APOBEC1 could serve as new PAAD predictors. The risk model developed in this study could be used to predict the prognosis of PAAD patients.

KLK7, KLK10, and KLK11 in Papillary Thyroid Cancer: Bioinformatic Analysis and Experimental Validation.

Despite many studies on papillary thyroid carcinoma (PTC) in the past few decades, some critical and significant genes remain undiscovered. To explore genes that may play crucial roles in PTC, a detailed analysis of the expression levels, mutations, and clinical significance of Kallikrein-related peptidases (KLKs) family genes in PTC was undertaken to provide new targets for the precise treatment of the disease. A comprehensive analysis of KLK family genes was performed using various online tools, such as GEPIA, Kaplan-Meier Plotter, LinkedOmics, GSCA, TIMER, and Cluego. KLK7, KLK10, and KLK11 were critical factors of KLK family genes. Then, functional assays were carried out on KLK7/10/11 to determine their proliferation, migration, and invasion capabilities in PTC. The mRNA expression levels of KLK7, KLK10, KLK11, and KLK13 were significantly elevated in thyroid carcinoma, while KLK1, KLK2, KLK3and KLK4 mRNA levels were decreased compared to normal tissues. Correlations between KLK2/7-12/15 expression levels and tumor stage were also observed in thyroid carcinoma. Survival analysis demonstrated that KLK4/5/7/9-12/14 was associated with overall survival in patients with thyroid cancer. Not only were KLK genes strongly associated with cancer-related pathways, but also KLK7/10/11 was associated with immune-cell infiltration. Finally, silencing KLK7/10/11 impaired human papillary thyroid carcinoma cells' growth, migration ability, and invasiveness. The increased expression of KLK7, KLK10, and KLK11 may serve as molecular markers to identify PTC patients. KLK7, KLK10, and KLK11 could be potential prognostic indicators and targets for precision therapy against PTC.

Deletion of Kallikrein-related peptidases ( Klks ) has no effect on fertility in mice.

Kallikreins (KLKs) are serine peptidases. It was established that Klks are estrogen-target genes in mouse uteri. However, the functional requirement of KLK family in the uterine function during reproduction is unknown. Here we generated a compound deletion of Klk1b3, Klk1b4, Klk1b5, and Klk1 in a mouse model using CRISPR/Cas9 strategy with four single guide RNAs (sgRNAs) to target the second exon of these four genes that are aligned back-to-back in a single locus spanning 32.95 kb on chromosome 7. We found that both male and female knockout mice are fertile with no apparent health defect compared to wild-type controls. Our data suggest that Klk1b3, Klk1b4, Klk1b5, and Klk1 are not necessary for male and female reproductive function in mice.

An integrated bioinformatic investigation of kallikrein gene family members in kidney renel cell carcinoma.

KLKs have been proved to be key regulators of the tumor microenvironment. In this study, we explored the potential of Kallikrein-related peptidases (KLKs) as clinical diagnostic and prognostic markers in patients with kidney renal clear cell carcinoma (KIRC) as well as their relationship with common immuno-inhibitor and immune cell infiltration in the tumor microenvironment to provide new targets and novel ideas for KIRC therapy. Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), UCSC Xena, Genotype-Tissue Expression (GTEx), Kaplan-Meier plotter, cBioPortal, STRING, GeneMANIA, and TISIDB were used to analyze the differential expression, prognostic value, gene changes, molecular interaction, and immune infiltration of KLKs in patients with KIRC. From the gene expression level, it can be determined that KLK1, KLK6, and KLK7 are differentially expressed in KIRC and normal tissues. From the perspective of clinical prognosis, KLK1, KLK13, and KLK14 are highly correlated with the clinical prognosis of KIRC. The expression of KLKs is regulated by various immunosuppressive agents, with KDR, PVRL2, and VTCN1 being the most significant. The expression of KLKs is significantly correlated with the infiltration of various immune cells, of which Eosinophils and Neutrophils are the most significant. KLK1, KLK6, KLK7, KLK13, and KLK14 have potential as diagnostic and prognostic biomarkers, among which KLK1 is the most significant. This study may provide detailed immune information and promising targets for KIRC immunotherapy to assist in designing new immunotherapies.

KLK10 promotes the progression of KRAS mutant colorectal cancer via PAR1-PDK1-AKT signaling pathway.

Kirsten rat sarcoma virus (KRAS) gene mutation is common in colorectal cancer (CRC) and is often predictive of treatment failure and poor prognosis. To understand the mechanism, we compared the transcriptome of CRC patients with wild-type and mutant KRASand found that KRAS mutation is associated with the overexpression of a secreted serine protease, kallikrein-related peptidase 10 (KLK10). Moreover, using in vitro and in vivo models, we found that KLK10 overexpression favors the rapid growth and liver metastasis of KRAS mutant CRCand can also impair the efficacy of KRAS inhibitors, leading to drug resistanceand poor survival. Further functional assays revealed that the oncogenic role of KLK10 is mediated by protease-activated receptor 1 (PAR1). KLK10 cleaves and activates PAR1, which further activates 3-phosphoinositide-dependent kinase 1 (PDK1)-AKT oncogenic pathway. Notably, suppressing PAR1-PDK1-AKT cascade via KLK10 knockdown can effectively inhibit CRC progression and improve the sensitivity to KRAS inhibitor, providing a promising therapeutic strategy. Taken together, our study showed that KLK10 promotes the progression of KRAS mutant CRC via activating PAR1-PDK1-AKT signaling pathway. These findings expanded our knowledge of CRC development, especially in the setting of KRAS mutation, and also provided novel targets for clinical intervention.

Gene Signature Associated with Nervous System in an Experimental Radiation- and Estrogen-Induced Breast Cancer Model.

Breast cancer is frequently the most diagnosed female cancer in the world. The experimental studies on cancer seldom focus on the relationship between the central nervous system and cancer. Despite extensive research into the treatment of breast cancer, chemotherapy resistance is an important issue limiting the efficacy of treatment. Novel biomarkers to predict prognosis or sensitivity to chemotherapy are urgently needed. This study examined nervous-system-related genes. The profiling of differentially expressed genes indicated that high-LET radiation, such as that emitted by radon progeny, in the presence of estrogen, induced a cascade of events indicative of tumorigenicity in human breast epithelial cells. Bioinformatic tools allowed us to analyze the genes involved in breast cancer and associated with the nervous system. The results indicated that the gene expression of the Ephrin A1 gene (EFNA1), the roundabout guidance receptor 1 (ROBO1), and the kallikrein-related peptidase 6 (KLK6) was greater in T2 and A5 than in the A3 cell line; the LIM domain kinase 2 gene (LIMK2) was greater in T2 than A3 and A5; the kallikrein-related peptidase 7 (KLK7), the neuroligin 4 X-linked gene (NLGN4X), and myelin basic protein (MBP) were greater than A3 only in T2; and the neural precursor cell expressed, developmentally down-regulated 9 gene (NEDD9) was greater in A5 than in the A3 and E cell lines. Concerning the correlation, it was found a positive correlation between ESR1 and EFNA1 in BRCA-LumA patients; with ROBO1 in BRCA-Basal patients, but this correlation was negative with the kallikrein-related peptidase 6 (KLK6) in BRCA-LumA and -LumB, as well as with LIMK2 and ROBO1 in all BRCA. It was also positive with neuroligin 4 X-linked (NLGN4X) in BRCA-Her2 and BRCA-LumB, and with MBP in BRCA-LumA and -LumB, but negative with KLK7 in all BRCA and BRCA-LumA and NEDD9 in BRCA-Her2. The differential gene expression levels between the tumor and adjacent tissue indicated that the ROBO1, KLK6, LIMK2, KLK7, NLGN4X, MBP, and NEDD9 gene expression levels were higher in normal tissues than in tumors; however, EFNA1 was higher in the tumor than the normal ones. EFNA1, LIMK2, ROBO1, KLK6, KLK7, and MBP gene expression had a negative ER status, whereas NEDD9 and NLGN4X were not significant concerning ER status. In conclusion, important markers have been analyzed concerning genes related to the nervous system, opening up a new avenue of studies in breast cancer therapy.

Kallikrein-related peptidase 10 predicts prognosis and mediates tumor immunomodulation in colorectal cancer

The incidence and mortality rates of colorectal cancer (CRC) have significantly increased in recent years. It has been shown that early diagnosis of CRC improves the five-year survival of patients compared to late diagnosis, as patients with stage I disease have a five-year survival rate as high as 90 %. Through bioinformatics analysis, we identified Kallikrein 10 (KLK10), a member of the Kallikrein family, as a reliable predictor of CRC progression, particularly in patients with early-stage CRC. Furthermore, single-cell analysis revealed that KLK10 was highly expressed in tumor and partial immune cells. Analysis of the biological functions of KLK10 using the Kyoto encyclopedia of genes and genomes and gene ontology indicated that KLK10 plays a role in the proliferation and differentiation of cancer cells, along with the maintenance of tumor function and immune regulation, explicitly by T cells and macrophages. EdU cell proliferation staining, plate clone formation assay, and cell scratch assay demonstrated that KLK10 inhibition by siRNA affected the proliferation and migration of CRC cells. Cell cycle detection by flow cytometry demonstrated that KLK10 inhibition led to cell cycle arrest in the G1 phase. In addition, the proportion of M1 and M2 macrophages in 45 tumor specimens was analyzed by immunohistochemistry, the proportion of CD4+ T cells and CD8+ T cells in plasma was identified by flow cytometry, and their correlation with KLK10 was analyzed. The effects of KLK10 on T cells and macrophages were verified in independent cell experiments. The results revealed that KLK10 also activates CD4+ T cells, mediating M2-type macrophage polarization.

Kallikrein-Related Peptidase 4 Promotes Proliferation, Migration, Invasion, and Pro-Angiogenesis of Endometrial Stromal Cells via Regulation of Brain-Derived Neurotrophic Factor Production in Endometriosis

Endometriosis is a common benign gynecologic condition. Endometriosis lesions are associated with endometrial cell proliferation, migration, invasion, and neovascularization, while the specific molecular mechanisms are still elusive. Transcriptome sequencing has been used for the identification of diagnostic markers in endometriosis. Here, transcriptome profiling revealed that kallikrein-related peptidase 4 (KLK4) expression was up-regulated in ectopic endometrium (EC) tissues of patients with endometriosis. KLK4 mediates the degradation of extracellular matrix proteins, and its proteolytic activity activates many tumorigenic and metastatic pathways via tumor invasion and migration. Nevertheless, whether KLK4 serves as an important regulatory factor in endometriosis remains unclear. This study confirmed that KLK4 was highly expressed in ectopic endometrial stromal cells (EC-ESCs). KLK4 overexpression promoted proliferation and suppressed apoptosis of EC-ESCs, induced cell migration and invasion, and enhanced angiogenesis invivo. Mechanistically, KLK4 overexpression mediated the protein cleavage of pro-brain-derived neurotrophic factor in EC-ESCs. Finally, brain-derived neurotrophic factor was a vital downstream substrate of KLK4 maintained the proliferation, metastasis, and pro-angiogenesis abilities and inhibited apoptosis of ESCs through a rescue study. Together, these findings demonstrate the promotive role of KLK4 in endometriosis development. In addition, the study provides a new insight that KLK4 might be a potential therapeutic target and prognostic marker for patients with endometriosis.

ASO Visual Abstract: Induction of Kallikrein-Related Peptidase 13 and TET2/3 by Anticancer Drugs and the Poor Prognosis for Patients with Esophageal Squamous Cell Carcinoma After Preoperative Treatment.

ASO Visual Abstract: Induction of Kallikrein-Related Peptidase 13 and TET2/3 by Anticancer Drugs and the Poor Prognosis for Patients with Esophageal Squamous Cell Carcinoma After Preoperative Treatment.