PAX2 oncogene negatively regulates the expression of the host defense peptide human beta defensin-1 in prostate cancer

Human β-defensins: The multi-functional natural peptide

The increasing threat of antibiotic resistance among pathogenic microorganisms and the urgent demand for new antibiotics require immediate attention. Antimicrobial peptides exhibit effectiveness against microorganisms, fungi, viruses, and protozoa. The discovery of human β-defensins represents a major milestone in biomedical research, opening new avenues for scientific investigation into the innate immune system and its resistance mechanisms against pathogenic microorganisms. Multiple defensins present a promising alternative in the context of antibiotic abuse. However, obstacles to the practical application of defensins as anti-infective therapies persist due to the unique properties of human β-defensins themselves and serious pharmacological and technical challenges. To overcome these challenges, diverse delivery vehicles have been developed and progressively improved for the conjugation or encapsulation of human β-defensins. This review briefly introduces the biology of human β-defensins, focusing on their multistage structure and diverse functions. It also discusses several heterologous systems for producing human β-defensins, various delivery systems created for these peptides, and patent applications related to their utilization, concluding with a summary of current challenges and potential solutions.

ERK1/2-CEBPB Axis-Regulated hBD1 Enhances Anti-Tuberculosis Capacity in Alveolar Type II Epithelial Cells

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a global health crisis with substantial morbidity and mortality rates. Type II alveolar epithelial cells (AEC-II) play a critical role in the pulmonary immune response against Mtb infection by secreting effector molecules such as antimicrobial peptides (AMPs). Here, human β-defensin 1 (hBD1), an important AMP produced by AEC-II, has been demonstrated to exert potent anti-tuberculosis activity. HBD1 overexpression effectively inhibited Mtb proliferation in AEC-II, while mice lacking hBD1 exhibited susceptibility to Mtb and increased lung tissue inflammation. Mechanistically, in A549 cells infected with Mtb, STAT1 negatively regulated hBD1 transcription, while CEBPB was the primary transcription factor upregulating hBD1 expression. Furthermore, we revealed that the ERK1/2 signaling pathway activated by Mtb infection led to CEBPB phosphorylation and nuclear translocation, which subsequently promoted hBD1 expression. Our findings suggest that the ERK1/2-CEBPB-hBD1 regulatory axis can be a potential therapeutic target for anti-tuberculosis therapy aimed at enhancing the immune response of AEC-II cells.

Roles of Different β-Defensins in the Human Reproductive System: A Review Study

Human β-defensins (hBDs) are cationic peptides with an amphipathic spatial shape and a high cysteine content. The members of this peptide family have been found in the human body with various functions, including the human reproductive system. Of among β-defensins in the human body, β-defensin 1, β-defensin 2, and β-defensin 126 are known in the human reproductive system. Human β-defensin 1 interacts with chemokine receptor 6 (CCR6) in the male reproductive system to prevent bacterial infections. This peptide has a positive function in antitumor immunity by recruiting dendritic cells and memory T cells in prostate cancer. It is necessary for fertilization via facilitating capacitation and acrosome reaction in the female reproductive system. Human β-defensin 2 is another peptide with antibacterial action which can minimize infection in different parts of the female reproductive system such as the vagina by interacting with CCR6. Human β-defensin 2 could play a role in preventing cervical cancer via interactions with dendritic cells. Human β-defensin 126 is required for sperm motility and protecting the sperm against immune system factors. This study attempted to review the updated knowledge about the roles of β-defensin 1, β-defensin 2, and β-defensin 126 in both the male and female reproductive systems.

In silico analysis of non-synonymous single nucleotide polymorphisms of human DEFB1 gene

Background

Single nucleotide polymorphisms (SNPs) play a significant role in differences in individual’s susceptibility to diseases, and it is imperative to differentiate potentially harmful SNPs from neutral ones. Defensins are small cationic antimicrobial peptides that serve as antimicrobial and immunomodulatory molecules, and SNPs in β-defensin 1 (DEFB1 gene) have been associated with several diseases. In this study, we have determined deleterious SNPs of the DEFB1 gene that can affect the susceptibility to diseases by using different computational methods. Non-synonymous SNPs (nsSNPs) of the DEFB1 gene that have the ability to affect protein structure and functions were determined by several in silico tools—SIFT, PolyPhen v2, PROVEAN, SNAP, PhD-SNP, and SNPs&GO. Then, nsSNPs identified to be potentially deleterious were further analyzed by I-Mutant and ConSurf. Post-translational modifications mediated by nsSNPs were predicted by ModPred, and gene-gene interaction was studied by GeneMANIA. Finally, nsSNPs were submitted to Project HOPE analysis.

Results

Ten nsSNPs of the DEFB1 gene were found to be potentially deleterious: rs1800968, rs55874920, rs56270143, rs140503947, rs145468425, rs146603349, rs199581284, rs201260899, rs371897938, rs376876621. I-Mutant server showed that nsSNPs rs140503947 and rs146603349 decreased stability of the protein, and ConSurf analysis revealed that SNPs were located in conserved regions. The physiochemical properties of the polymorphic amino acid residues and their effect on structure were determined by Project HOPE.

Conclusion

This study has determined high-risk deleterious nsSNPs of β-defensin 1 and could increase the knowledge of nsSNPs towards the impact of mutations on structure and functions mediated by β-defensin 1 protein.

Broad genic repression domains signify enhanced silencing of oncogenes

Cancers result from a set of genetic and epigenetic alterations. Most known oncogenes were identified by gain-of-function mutations in cancer, yet little is known about their epigenetic features. Through integrative analysis of 11,596 epigenomic profiles and mutations from >8200 tumor-normal pairs, we discover broad genic repression domains (BGRD) on chromatin as an epigenetic signature for oncogenes. A BGRD is a widespread enrichment domain of the repressive histone modification H3K27me3 and is further enriched with multiple other repressive marks including H3K9me3, H3K9me2, and H3K27me2. Further, BGRD displays widespread enrichment of repressed cis-regulatory elements. Shortening of BGRDs is linked to derepression of transcription. BGRDs at oncogenes tend to be conserved across normal cell types. Putative tumor-promoting genes and lncRNAs defined using BGRDs are experimentally verified as required for cancer phenotypes. Therefore, BGRDs play key roles in epigenetic regulation of cancer and provide a direction for mutation-independent discovery of oncogenes.

Epigenetically altered genes can have a key role in cancer pathobiology but epigenetic signatures that distinguish oncogenes are not yet known. Here, the authors identify broad genic repression domains, defined by widespread H3K27me3 modification, as an epigenetic signature to provide mutation-independent information for discovery of potential oncogenes.

Human Beta Defensins and Cancer: Contradictions and Common Ground

Human beta-defensins (hBDs, −1, 2, 3) are a family of epithelial cell derived antimicrobial peptides (AMPs) that protect mucosal membranes from microbial challenges. In addition to their antimicrobial activities, they possess other functions; e.g., cell activation, proliferation, regulation of cytokine/chemokine production, migration, differentiation, angiogenesis, and wound healing processes. It has also become apparent that defensin levels change with the development of neoplasia. However, inconsistent observations published by various laboratories make it difficult to reach a consensus as to the direction of the dysregulation and role the hBDs may play in various cancers. This is particularly evident in studies focusing on oral squamous cell carcinoma (OSCC). By segregating each hBD by cancer type, interrogating methodologies, and scrutinizing the subject cohorts used in the studies, we have endeavored to identify the “take home message” for each one of the three hBDs. We discovered that (1) consensus-driven findings indicate that hBD-1 and−2 are down- while hBD-3 is up-regulated in OSCC; (2) hBD dysregulation is cancer-type specific; (3) the inhibition/activation effect an hBD has on cancer cell lines is related to the direction of the hBD dysregulation (up or down) in the cancer from which the cell lines derive. Therefore, studies addressing hBD dysregulation in various cancers are not generalizable and comparisons should be avoided. Systematic delineation of the fate and role of the hBDs in a specific cancer type may lead to innovative ways to use defensins as prospective biomarkers for diagnostic/prognostic purposes and/or in novel therapeutic modalities.

Differential transactivation of the upstream aggrecan enhancer regulated by PAX1/9 depends on SOX9-driven transactivation

A previously identified enhancer 10 kb upstream of the Aggrecan (Acan) gene (UE) can drive cartilage specific reporter expression in vivo. Here, we report that the paralogous transcription factors PAX1 and PAX9 differentially drive UE, depending on the presence or absence of SOX9-driven transactivation. In the developing vertebral column, PAX1/9 expression was inversely correlated with Acan expression. Moreover, PAX1/9 was co-expressed with SOX9/5/6 in the intervertebral mesenchyme and the inner annulus fibrosus (AF), and with SOX9 in the outer AF. Significant Acan upregulation was observed during chondrification of Pax1-silenced AF cells, while, Acan was significantly downregulated by persistent expression of Pax1 in cartilage. Deletion of UE using CRISPR/Cas9 resulted in ~30% and ~40% reduction of Acan expression in cartilage and the AF, respectively. In the UE, PAX1/9 acts as weak transactivators through a PAX1/9-binding site partially overlapped with a SOX9-binding site. In the presence of SOX9, which otherwise drives robust Acan expression along with SOX5/6, PAX1/9 competes with SOX9 for occupancy of the binding site, resulting in reduced transactivation of Acan. Coimmunoprecipitation revealed the physical interaction of Pax1 with SOX9. Thus, transactivation of the UE is differentially regulated by concerted action of PAX1/9, SOX9, and SOX5/6 in a context-dependent manner.

Expression of the human antimicrobial peptide β-defensin-1 is repressed by the EGFR-ERK-MYC axis in colonic epithelial cells

The human β-defensin-1 (HBD1) is an antimicrobial peptide constitutively expressed by epithelial cells at mucosal surfaces. In addition to its microbicidal properties, the loss of HBD1 expression in several cancers suggests that it may also have an anti-tumor activity. Here, we investigated the link between HBD1 expression and cancer signaling pathways in the human colon cancer cell lines TC7 and HT-29, and in normal human colonic primary cells, using a mini-gut organoid model. Using available datasets from patient cohorts, we found that HBD1 transcription is decreased in colorectal cancer. We demonstrated that inhibiting the Epidermal Growth Factor Receptor (EGFR) increased HBD1 expression, whereas activating EGFR repressed HBD1 expression, through the MEKK1/2-ERK1/2 pathway that ultimately regulates MYC. We finally present evidences supporting a role of MYC, together with the MIZ1 coregulator, in HBD1 regulation. Our work uncovers the role and deciphers the function of the EGFR-ERK-MYC axis as a repressor of HBD1 expression and contributes to the understanding of HBD1 suppression observed in colorectal cancer.

EGFR-targeting, β-defensin-tailored fusion protein exhibits high therapeutic efficacy against EGFR-expressed human carcinoma via mitochondria-mediated apoptosis

Defensins play an essential role in innate immunity. In this study, a novel recombinant β-defensin that targets the epidermal growth factor receptor (EGFR) was designed and prepared. The EGFR-targeting β-defensin consists of an EGF-derived oligopeptide (Ec), a β-defensin-1 peptide (hBD1) and a lidamycin-derived apoprotein (LDP), which serves as the "scaffold" for the fusion protein (Ec-LDP-hBD1). Ec-LDP-hBD1 effectively bound to EGFR highly expressed human epidermoid carcinoma A431 cells. The cytotoxicity of Ec-LDP-hBD1 to EGFR highly expressed A431 cells was more potent than that to EGFR low-expressed human lung carcinoma A549 and H460 cells (the IC₅₀ values in A431, A549, and H460 cells were 1.8 ± 0.55, 11.9 ± 0.51, and 5.19 ± 1.21 μmol/L, respectively); in addition, the cytotoxicity of Ec-LDP-hBD1 was much stronger than that of Ec-LDP and hBD1. Moreover, Ec-LDP-hBD1 suppressed cancer cell proliferation and induced mitochondria-mediated apoptosis. Its in vivo anticancer action was evaluated in athymic mice with A431 and H460 xenografts. The mice were administered Ec-LDP-hBD1 (5, 10 mg/kg, i.v.) two times with a weekly interval. Administration of Ec-LDP-hBD1 markedly inhibited the tumor growth without significant body weight changes. The in vivo imaging further revealed that Ec-LDP-hBD1 had a tumor-specific distribution with a clear image of localization. The results demonstrate that the novel recombinant EGFR-targeting β-defensin Ec-LDP-hBD1 displays both selectivity and enhanced cytotoxicity against relevant cancer cells by inducing mitochondria-mediated apoptosis and exhibits high therapeutic efficacy against the EGFR-expressed carcinoma xenograft. This novel format of β-defensin, which induces mitochondrial-mediated apoptosis, may play an active role in EGFR-targeting cancer therapy.

Paired box 2 promotes progression of endometrial cancer via regulating cell cycle pathway

Background: Human paired box 2 (PAX2) plays a key role in cell fate, early patterning and organogenesis.

Methods: We investigated the function of PAX2 on the biological behavior of endometrial cancer in vitro and in vivo and to explore the regulation mechanism, stable knocking-down and over-expression PAX2 endometrial cancer cell lines were established. CCK-8 and transwell assays were applied to determine proliferation, invasion and migration ability. Cell cycle distribution was analyzed by flow cytometry. Affymetrix GeneChip® human Exon 1.0 ST arrays was used to screen the downstream target genes of PAX2.

Results: PAX2 significantly enhanced proliferation and invasiveness. In addition, PAX2 influenced the expression of cyclin-dependent kinase 1(CDK1), which play pivotal roles in cell cycle pathway. When CDK1 was knocked down, and the cell proliferation promotion role of PAX2 was attenuated dramatically to a level comparable with the control groups.

Conclusions: PAX2, though influencing the expression of CDK1, promotes the proliferation, enhances the mobility of endometrial cancer cells, thus exerts an important role in the carcinogenesis of endometrial cancer. PAX2 may be a potential therapeutic target for endometrial cancer.

CP-31398 inhibits the progression of cervical cancer through reversing the epithelial mesenchymal transition via the downregulation of PAX2s

CP-31398, a styrylquinazoline, emerges from a screen for therapeutic agents that restore the wild-type DNA-binding conformation of mutant p53 to suppress tumors in vivo, but its effects on cervical cancer (CC) remain unknown. Hence, this study aimed to explore the effects CP-31398 has on the CC cells and to investigate whether it is associated with paired box 2 (PAX2) expression. CC cells were treated with different concentrations of CP-31398 (1, 2, 4, 6, 8, and 10 μg/ml) to determine the optimum concentration using fluorometric microculture cytotoxicity assay. After constructing the sh-PAX2 vector, CC cells were transfected with sh-PAX2 or treated with CP-31398. The effects of CP-31398 or PAX2 silencing on CC cell proliferation, apoptosis, invasion, and migration were evaluated. Epithelial mesenchymal transition (EMT)-related genes such as E-cadherin, vimentin, N-cadherin, snail, and twist in CC cells were detected. Tumor formation experiment in nude mice was performed to observe tumor growth. The optimum concentration of CP-31398 was 2 μg/ml. PAX2 was overexpressed in CC cells. CC cells treated with CP-31398 or treated with sh-PAX2 inhibited proliferation, invasion, and migration but promoted apoptosis with decreased PAX2 expression. The EMT process in CC cells was also reversed after treatment with CP-31398 or sh-PAX2. Moreover, the tumor formation experiment in nude mice revealed the inhibitory activity of CP-31398 in CC tumor in nude mice by suppressing PAX2. Our results provide evidence that CP-31398 could inhibit EMT and promote apoptosis of CC cells to curb CC tumor growth by downregulating PAX2.

Emerging roles of T helper 17 and regulatory T cells in lung cancer progression and metastasis

Lung cancer is a leading cause of cancer-related deaths worldwide. Lung cancer risk factors, including smoking and exposure to environmental carcinogens, have been linked to chronic inflammation. An integral feature of inflammation is the activation, expansion and infiltration of diverse immune cell types, including CD4⁺ T cells. Within this T cell subset are immunosuppressive regulatory T (Treg) cells and pro-inflammatory T helper 17 (Th17) cells that act in a fine balance to regulate appropriate adaptive immune responses.In the context of lung cancer, evidence suggests that Tregs promote metastasis and metastatic tumor foci development. Additionally, Th17 cells have been shown to be an integral component of the inflammatory milieu in the tumor microenvironment, and potentially involved in promoting distinct lung tumor phenotypes. Studies have shown that the composition of Tregs and Th17 cells are altered in the tumor microenvironment, and that these two CD4⁺ T cell subsets play active roles in promoting lung cancer progression and metastasis.We review current knowledge on the influence of Treg and Th17 cells on lung cancer tumorigenesis, progression, metastasis and prognosis. Furthermore, we discuss the potential biological and clinical implications of the balance among Treg/Th17 cells in the context of the lung tumor microenvironment and highlight the potential prognostic function and relationship to metastasis in lung cancer.

Genome-Wide Copy Number Variation Scan Identifies Complement Component C4 as Novel Susceptibility Gene for Crohn's Disease

BACKGROUND

The genetic component of Crohn's disease (CD) is well known, with 140 susceptibility loci identified so far. In addition to single nucleotide polymorphisms typically studied in genome-wide scans, copy number variation is responsible for a large proportion of human genetic variation.

METHODS

We performed a genome-wide search for copy number variants associated with CD using array comparative genomic hybridization. One of the found regions was validated independently through real-time PCR. Serum levels of the found gene were measured in patients and control subjects.

RESULTS

We found copy number differences for the C4S and C4L gene variants of complement component C4 in the central major histocompatibility complex region on chromosome 6p21. Specifically, we saw that CD patients tend to have lower C4L and higher C4S copies than control subjects (P = 5.00 × 10 and P = 9.11 × 10), which was independent of known associated classical HLA I and II alleles (P = 7.68 × 10 and P = 6.29 × 10). Although C4 serum levels were not different between patients and control subjects, the relationship between C4 copy number and serum level was different for patients and control subjects with higher copy numbers leading to higher serum concentrations in control subjects, compared with CD patients (P < 0.001).

CONCLUSIONS

C4 is part of the classical activation pathway of the complement system, which is important for (auto)immunity. Low C4L or high C4S copy number, and corresponding effects on C4 serum level, could lead to an exaggerated response against infections, possibly leading to (auto)immune disease.

Human beta-defensin-1 suppresses tumor migration and invasion and is an independent predictor for survival of oral squamous cell carcinoma patients

Background

Human beta-defensin-1 (hBD-1) has recently been considered as a candidate tumor suppressor in renal and prostate cancer. The aim of this study was to investigate the role of hBD-1 in the progression of oral squamous cell carcinoma (OSCC) and its potential as diagnostic/prognostic biomarker and therapeutic target for OSCC.

Methods

HBD-1 expression in tissues at different stages of oral carcinogenesis, as well as OSCC cell lines was examined. HBD-1 was overexpressed in HSC-3, UM1, SCC-9 and SCC-25 cells and subjected to cell growth, apoptosis, migration and invasion assays. Tissue microarray constructed with tissues from 175 patients was used to examine clinicopathological significance of hBD-1 expression in OSCC.

Results

HBD-1 expression decreased from oral precancerous lesions to OSCC and was lower in OSCC with lymph node metastasis than those without metastasis. In vitro, the expression of hBD-1 was related to the invasive potential of OSCC cell lines. Induction of exogenous expression of hBD-1 inhibited migration and invasion of OSCC cells, probably by regulation of RhoA, RhoC and MMP-2; but had no significant effect on proliferation or apoptosis. In a cohort of patients with primary OSCC, cases with no expression of hBD-1 had more chance to be involved in lymph node metastasis. Eventually, the positive expression of hBD-1 was associated with longer survival of patients with OSCC, and multivariate analysis and ROC curve analysis confirmed hBD-1 positivity to be an independent prognostic factor of OSCC, especially OSCC at early stage.

Conclusions

Overall, these data indicated that hBD-1 suppressed tumor migration and invasion of OSCC and was likely to be a prognostic biomarker and a potential target for treatment of OSCC.

Beta defensin-1 gene polymorphisms and susceptibility to atypical squamous cells of undetermined significance lesions in Italian gynecological patients

The role of the human beta-defensin 1 (hBD-1) in the susceptibility to the onset of the Atypical Squamous Cells of Undetermined Significance (ASCUS) lesion, in the presence or not of HPV infection, is still unknown. In the current study, the three functional single nucleotide polymorphisms (SNPs) -52G > A, -44C > G, and -20G > A at the 5' un-translated region (UTR) of DEFB1 gene, encoding hBD-1, were analyzed in ASCUS lesion gynecological patients and healthy women from the north-east of Italy (Trieste). Cervical samples from 249 European-Caucasian women were collected, screened for HPV and cytologically evaluated; DEFB1 genotyping has been performed by direct sequencing. No significant differences were found for -52G > A, -44C > G, and -20G > A SNPs allele and genotype frequencies between women with and without ASCUS lesions. DEFB1 minor haplotypes were significantly more frequent in ASCUS lesion positive than negative women, associating with an increased risk of this type of lesion. When women were stratified according to HPV infection status, significant differences in the distribution of -52G > A SNP genotype frequencies were found: the presence of the A allele in the homozygous genotype A/A associated with a lower risk of developing ASCUS lesions in HPV negative women. DEFB1 minor haplotypes were also associated with an increased risk of developing ASCUS lesions, being significantly more frequent in HPV negative women with lesions, than without lesions. Although these results highlight the possible involvement of DEFB1, further studies are needed to support the role of DEFB1 in the modulation of the susceptibility to ASCUS lesions.

Antimicrobial peptides and gut microbiota in homeostasis and pathology

We survive because we adapted to a world of microorganisms. All our epithelial surfaces participate in keeping up an effective barrier against microbes while not initiating ongoing inflammatory processes and risking collateral damage to the host. Major players in this scenario are antimicrobial peptides (AMPs). Such broad-spectrum innate antibiotics are in part produced by specialized cells but also widely sourced from all epithelia as well as circulating inflammatory cells. AMPs belong to an ancient defense system found in all organisms and participated in a preservative co-evolution with a complex microbiome. Particularly interesting interactions between host barrier and microbiota can be found in the gut. The intestinal cell lining not only has to maintain a tightly regulated homeostasis during its high-throughput regeneration, but also a balanced relationship towards an extreme number of mutualistic or commensal inhabitants. Recent research suggests that advancing our understanding of the circumstances of such balanced and sometimes imbalanced interactions between gut microbiota and host AMPs should have therapeutic implications for different intestinal disorders.

Association between graves' disease and renal coloboma syndrome: a case report

Renal coloboma syndrome is an autosomal dominant condition characterized by renal lesions and optic nerve abnormalities. We report an 11-yr-old Japanese girl with familial renal coloboma syndrome, who also had Graves’ disease. Four affected family members had a previously reported heterozygous mutation (c.76dupG, p.Val26Glyfs*28) in the PAX2 gene. We hypothesized that PAX2 mutations may increase the risk of autoimmune diseases through alterations of human β-defensin 1 expression.

Association between graves' disease and renal coloboma syndrome: a case report

Renal coloboma syndrome is an autosomal dominant condition characterized by renal lesions and optic nerve abnormalities. We report an 11-yr-old Japanese girl with familial renal coloboma syndrome, who also had Graves' disease. Four affected family members had a previously reported heterozygous mutation (c.76dupG, p.Val26Glyfs*28) in the PAX2 gene. We hypothesized that PAX2 mutations may increase the risk of autoimmune diseases through alterations of human β-defensin 1 expression.

Less expression of prohibitin is associated with increased paired box 2 (PAX2) in renal interstitial fibrosis rats

Prohibitin (PHB) and paired box 2 (PAX2) are associated with the development of renal interstitial fibrosis (RIF). This study was performed to investigate whether or not the PHB could regulate the PAX2 gene expression in unilateral ureteral obstruction (UUO) in rats. Eighty Wistar male rats were randomly divided into two groups: sham operation group (SHO) and model group subjected to unilateral ureteral obstruction (GU), n = 40, respectively. The model was established by left ureteral ligation. Renal tissues were collected at 14-day and 28-day after surgery. RIF index, protein expression of PHB, PAX2, transforming growth factor-βl (TGF-β1), α-smooth muscle actin (α-SMA), collagen-IV (Col-IV), fibronectin (FN) or cleaved Caspase-3, and cell apoptosis index in renal interstitium, and mRNA expressions of PHB, PAX2 and TGF-β1 in renal tissue were detected. When compared with those in SHO group, expression of PHB (mRNA and protein) was significantly reduced, and expressions of PAX2 and TGF-β1 (protein and mRNA) were markedly increased in the GU group (each p < 0.01). Protein expressions of α-SMA, Col-IV, FN and cleaved Caspase-3, and RIF index or cell apoptosis index in the GU group were markedly increased when compared with those in the SHO group (each p < 0.01). The protein expression of PHB was negatively correlated with protein expression of PAX2, TGF-β1, α-SMA, Col-IV, FN or cleaved Caspase-3, and RIF index or cell apoptosis index (all p < 0.01). In conclusion, less expression of PHB is associated with increased PAX2 gene expression and RIF index in UUO rats, suggesting that increasing the PHB expression is a potential therapeutic target for prevention of RIF.

Human β-defensins and psoriasin/S100A7 expression in salivary glands: anti-oncogenic molecules for potential therapeutic approaches

BACKGROUND

Host defence peptides (HDPs), including human β-defensins (hBDs) and psoriasin/S100A7, exert antimicrobial and immunoregulatory functions of the innate defense system. In addition to these functions, the search for cancer biomarkers has identified HDPs as playing a potential role in both tumor suppression and oncogenesis. Although HDPs are highly expressed in salivary glands, their role as molecules for potential diagnostic and therapeutic approaches has not yet been analyzed.

OBJECTIVE

The aim of the present study was to investigate whether expression levels of putative pro- or anti-oncogenic hBDs, including hBD-1, -2, -3, and psoriasin/S100A7, are altered in salivary gland tumor tissue as potential targets for molecular-based therapeutic approaches.

METHODS

We analyzed the expression levels of hBD-1, -2, -3, and psoriasin/S100A7 by quantitative real-time polymerase chain reaction (qrt-PCR) and immunohistochemistry in a case control study by comparing salivary gland tumor samples relative to healthy control specimens from 58 patients. Expression level analysis of hBD-1, -2, -3, and psoriasin/S100A7 by qrt-PCR was normalized to the endogenous 18S rRNA expression levels.

RESULTS

The results demonstrate the significant downregulation of hBD-1 (p < 0.001), hBD-2 (p = 0.003), hBD-3 (p = 0.002), and psoriasin/S100A7 (p = 0.003) mRNA in human salivary gland tumors compared with healthy control specimens. Protein expression levels of hBD-1, -2, -3, and psoriasin/S100A7 in salivary gland tumor tissue were strongly reduced compared with healthy control specimens.

CONCLUSION

The data indicates a putative role of the innate defense system in salivary gland tumor formation. The identification of immunoregulatory molecules as diagnostic biomarkers or therapeutic targets could provide new approaches for molecular-based diagnostic and therapeutic support to treat salivary gland tumors as well as other malignancies. We suggest that HDPs should be taken into consideration for use in molecular-based therapeutic approaches.

Association of PAX2 with cell apoptosis in unilateral ureteral obstruction rats

Renal interstitial fibrosis (RIF) is the final common pathway for chronic kidney disease. Cell apoptosis is a critical detrimental event that leads to renal fibrosis. Paired box 2 (PAX2) plays a major role in the development of the kidney. This study was performed to investigate whether PAX2 was associated with cell apoptosis in the progression of RIF in unilateral ureteral obstruction (UUO) rats. Eighty Wistar male rats were divided into two groups randomly: sham operation group (SHO) and model group subjected to UUO (GU), n = 40, respectively. The model was established by left ureteral ligation. Renal tissues were collected 14 and 28 days after surgery. Protein expressions of PAX2, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), collagen-IV (Col-IV), fibronectin (FN), and caspase-3 were detected using immunohistochemical analysis; mRNA expression of PAX2 in renal tissue was detected by real-time reverse transcription polymerase chain reaction; and RIF index and cell apoptosis index in renal interstitium were also calculated. When compared with those in the SHO group, expressions of PAX2 (protein and mRNA) were markedly increased in the GU group (each p < 0.01). Protein expressions of TGF-β1, α-SMA, Col-IV, FN, and caspase-3 and RIF index and cell apoptosis index in the GU group were remarkably increased when compared with those in the SHO group (each p < 0.01). The protein expression of PAX2 was positively correlated with the protein expressions of TGF-β1, α-SMA, Col-IV, FN, and caspase-3 and with RIF index and cell apoptosis index (all p < 0.01). The apoptotic cell in our observation was mainly derived from renal tubular epithelial cells. In conclusion, the increased expression of PAX2 is associated with cell apoptosis in the progression of RIF in UUO rats, suggesting that PAX2 is a potentially therapeutic target for prevention of RIF. Tian-Biao Zhou and Yuan-Han Qin wish it to be known that, in their opinion, they should be regarded as joint first authors.

Alzheimer's Disease: APP, Gamma Secretase, APOE, CLU, CR1, PICALM, ABCA7, BIN1, CD2AP, CD33, EPHA1, and MS4A2, and Their Relationships with Herpes Simplex, C. Pneumoniae, Other Suspect Pathogens, and the Immune System

Alzheimer's disease susceptibility genes, APP and gamma-secretase, are involved in the herpes simplex life cycle, and that of other suspect pathogens (C. pneumoniae, H. pylori, C. neoformans, B. burgdorferri, P. gingivalis) or immune defence. Such pathogens promote beta-amyloid deposition and tau phosphorylation and may thus be causative agents, whose effects are conditioned by genes. The antimicrobial effects of beta-amyloid, the localisation of APP/gamma-secretase in immunocompetent dendritic cells, and gamma secretase cleavage of numerous pathogen receptors suggest that this network is concerned with pathogen disposal, effects which may be abrogated by the presence of beta-amyloid autoantibodies in the elderly. These autoantibodies, as well as those to nerve growth factor and tau, also observed in Alzheimer's disease, may well be antibodies to pathogens, due to homology between human autoantigens and pathogen proteins. NGF or tau antibodies promote beta-amyloid deposition, neurofibrillary tangles, or cholinergic neuronal loss, and, with other autoantibodies, such as anti-ATPase, are potential agents of destruction, whose formation is dictated by sequence homology between pathogen and human proteins, and thus by pathogen strain and human genes. Pathogen elimination in the ageing population and removal of culpable autoantibodies might reduce the incidence and offer hope for a cure in this affliction.

Increased expression of beta-defensin 1 (DEFB1) in chronic obstructive pulmonary disease

On-going airway inflammation is characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the key factors determining the decrease in lung function, an important clinical parameter of COPD, are not clear. Genome-wide linkage analyses provide evidence for significant linkage to airway obstruction susceptibility loci on chromosome 8p23, the location of the human defensin gene cluster. Moreover, a genetic variation in the defensin beta 1 (DEFB1) gene was found to be associated with COPD. Therefore, we hypothesized that DEFB1 is differently regulated and expressed in human lungs during COPD progression. Gene expression of DEFB1 was assessed in bronchial epithelium and BAL fluid cells of healthy controls and patients with COPD and using bisulfite sequencing and ChIP analysis, the epigenetic control of DEFB1 mRNA expression was investigated. We can demonstrate that DEFB1 mRNA expression was significantly increased in bronchopulmonary specimen of patients with COPD (n = 34) vs. healthy controls (n = 10) (p<0.0001). Furthermore, a significant correlation could be detected between DEFB1 and functional parameters such as FEV₁ (p = 0.0024) and the FEV₁/VC ratio (p = 0.0005). Upregulation of DEFB1 mRNA was paralleled by changes in HDAC1-3, HDAC5 and HDAC8 mRNA expression. Whereas bisulfite sequencing revealed no differences in the methylation state of DEFB1 promoter between patients with COPD and controls, ChIP analysis showed that enhanced DEFB1 mRNA expression was associated with the establishment of an active histone code. Thus, expression of human DEFB1 is upregulated and related to the decrease in pulmonary function in patients with COPD.

Characterization of a New Monoclonal Antibody Against PAX5/BASP in 1525 Paraffin-embedded Human and Animal Tissue Samples

INTRODUCTION

We describe the newly generated DAK-PAX5 monoclonal antibody raised against a fixation-resistant epitope of the human PAX5/BSAP molecule.

MATERIALS AND METHODS

Following Western-blot, absorption, and chess-board titration tests, and optimization of antigen-retrieval and detection methods, DAK-Pax5 was used in parallel with a reference antibody (clone 24) on tissue micro-arrays (TMAs) constructed from normal human and animal tissues and from hematologic and nonhematologic human malignancies. Such TMAs were also tested with an anti-PAX2 antibody.

RESULTS

DAK-Pax5 reacted with normal human and animal B-cells and with 460/473 B-cell non-Hodgkin lymphomas (B-NHLs). All plasmacytomas/plasmablastic tumors (n=13) and T/NK-cell neoplasms (n=264) turned out consistently negative as did acute myelogenous leukaemias (n=19) except 2 carrying t(8;21). Positivity was found in 6/6 and 155/169 lymphocyte predominant and classical HLs, respectively, although the staining intensity varied through cases. Among 521 nonhematologic malignancies, DAK-Pax5 reacted with 22/399 carcinomas (4/11 neuroendocrine, 2/4 Merkel-cell, 4/21 prostatic, 1/11 urothelial, 1/26 renal, 2/12 cervical squamous-cell, 3/13 ovarian, and 5/75 colonic). When compared with clone 24, DAK-Pax5 produced a stronger positivity in most if not all B-NHLs and HLs. No cross-reactivity with the anti-PAX2 antibody was recorded.

DISCUSSION

DAK-Pax5 represents a new reliable tool for diagnostics and research.

Potential therapeutic application of host defense peptides

Host defense peptides (HDPs) are relatively small, mostly cationic, amphipathic, and of variable length, sequence, and structure. The majority of these peptides exhibit broad-spectrum antimicrobial activity and often activity against viruses and some cancer cell lines. In addition, HDPs also provide a range of immunomodulatory activities related to innate immunity defense, inflammation, and wound healing. The development of these multi-faceted molecules and their bioactivities into clinically important therapeutics is being pursued using a number of different approaches. Here we review the role of HDPs in nature and application of this role to the development of novel therapeutics.

Host defense peptides as effector molecules of the innate immune response: a sledgehammer for drug resistance?

Host defense peptides can modulate the innate immune response and boost infection-resolving immunity, while dampening potentially harmful pro-inflammatory (septic) responses. Both antimicrobial and/or immunomodulatory activities are an integral part of the process of innate immunity, which itself has many of the hallmarks of successful anti-infective therapies, namely rapid action and broad-spectrum antimicrobial activities. This gives these peptides the potential to become an entirely new therapeutic approach against bacterial infections. This review details the role and activities of these peptides, and examines their applicability as development candidates for use against bacterial infections.

Angiotensin II up-regulates PAX2 oncogene expression and activity in prostate cancer via the angiotensin II type I receptor

BACKGROUND

Paired homeobox 2 gene (PAX2) is a transcriptional regulator, aberrantly expressed in prostate cancer cells and its down-regulation promotes cell death in these cells. The molecular mechanisms of tumor progression by PAX2 over-expression are still unclear. However, it has been reported that angiotensin-II (A-II) induces cell growth in prostate cancer via A-II type 1 receptor (AT1R) and is mediated by the phosphorylation of mitogen activated protein kinase (MAPK) as well as signal transducer and activator of transcription 3 (STAT3).

METHODS

Here we have demonstrated that A-II up-regulates PAX2 expression in prostate epithelial cells and prostate cancer cell lines resulting in increased cell growth. Furthermore, AT1R receptor antagonist losartan was shown to inhibit A-II induced PAX2 expression in prostate cancer. Moreover, analysis using pharmacological inhibitors against MEK1/2, ERK1/2, JAK-II, and phospho-STAT3 demonstrated that AT1R-mediated stimulatory effect of A-II on PAX2 expression was regulated in part by the phosphorylation of ERK1/2, JAK II, and STAT3 pathways. In addition, we have showed that down-regulation of PAX2 by an AT1R antagonist as well as JAK-II and STAT3 inhibitors suppress prostate cancer cell growth.

RESULTS

Collectively, these findings show for the first time that the renin-angiotensin system (RAS) may promote prostate tumorigenesis via up-regulation of PAX2 expression.

CONCLUSIONS

Therefore, PAX2 may be a novel therapeutic target for the treatment of carcinomas such as prostate cancer via the down-regulation of its expression by targeting the AT1R signaling pathways.

An intron 9 containing splice variant of PAX2

BACKGROUND

PAX2 is a transcription factor with an important role in embryogenic development. However, PAX2 expression was frequently identified in neoplasia responsible for the growth and survival of cancer cells. Due to alternative splicing of exon 6, exon 10 and exon 12 four isoforms of PAX2 are described so far.

METHODS

The expression of an intron 9 containing PAX2 splice variant was analyzed in neoplastic B cell and solid tumor cell lines as well as in primary tumor samples by quantitative RT-PCR. PAX2 proteins were detected by Western Blot in a subset of cell lines.

RESULTS

All 14 lymphoma cell lines expressed an undescribed PAX2 splice variant containing the entire intron 9 sequence and the exon 10 sequence. This splice variant could also be detected in 35 solid tumor cell lines, in leukemia and lymphoma as well as in colon carcinoma and melanoma patient samples and in blood samples of healthy donors. Expression of this new splice variant on protein level was verified by Western Blot analysis.

CONCLUSION

We discovered a previously undescribed intron 9 and exon 10 containing splice variant of PAX2 in B-cell neoplasia and in solid tumors on mRNA and protein level.