Human prostatic acid phosphatase: structure, function and regulation

One-pot hydrothermal synthesis of silicon, nitrogen co-doped carbon dots for enhancing enzyme activity of acid phosphatase (ACP) to dopamine and for cell imaging

Developing water-soluble nanomaterials with high photoluminescence emission and high yield for biological analysis and imaging is urgently needed. Herein, water-soluble blue emitting silicon and nitrogen co-doped carbon dots (abbreviated as Si-CDs) of a high photoluminescence quantum yield of 80 % were effectively prepared with high yield rate (59.1 %) via one-step hydrothermal treatment of N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO) and trans-aconitic acid. Furthermore, the Si-CDs demonstrate environmental robustness, photo-stability and biocompatibility. Given the importance of the potentially abnormal levels of acid phosphatase (ACP) in cancer diagnosis, developing a reliable and sensitive ACP measurement method is of significance for clinical research. The Si-CDs unexpectedly promote the catalytic oxidation of ACP on dopamine (DA) to polydopamine under acidic conditions through the produced reactive oxygen species (ROS). Correspondingly, a fluorescence response strategy using Si-CDs as the dual functions of probes and promoting enzyme activity of ACP on catalyzing DA was constructed to sensitively determine ACP. The quantitative analysis of ACP displayed a linear range of 0.1-60 U/L with a detection limit of 0.056 U/L. The accurate detection of ACP was successfully achieved in human serum through recovery tests. As a satisfactory fluorescent probe, Si-CDs were successfully applied to fluorescent imaging of A549 cells in cytoplasmic with long-term and safe staining. The Si-CDs have the dual properties of outstanding fluorescent probes and auxiliary oxidase activity, indicating their great potential in multifunctional applications.

Purification, identification and Cryo-EM structure of prostatic acid phosphatase in human semen

Prostatic acid phosphatase (PAP) is a glycoprotein that plays a crucial role in the hydrolysis of phosphate ester present in prostatic exudates. It is a well-established indicator for prostate cancer due to its elevated serum levels in disease progression. Despite its abundance in semen, PAP's influence on male fertility has not been extensively studied. In our study, we report a significantly optimized method for purifying human endogenous PAP, achieving remarkably high efficiency and active protein recovery rate. This achievement allowed us to better analyze and understand the PAP protein. We determined the cryo-electron microscopic (Cryo-EM) structure of prostatic acid phosphatase in its physiological state for the first time. Our structural and gel filtration analysis confirmed the formation of a tight homodimer structure of human PAP. This functional homodimer displayed an elongated conformation in the cryo-EM structure compared to the previously reported crystal structure. Additionally, there was a notable 5-degree rotation in the angle between the α domain and α/β domain of each monomer. Through structural analysis, we revealed three potential glycosylation sites: Asn94, Asn220, and Asn333. These sites contained varying numbers and forms of glycosyl units, suggesting sugar moieties influence PAP function. Furthermore, we found that the active sites of PAP, His44 and Asp290, are located between the two protein domains. Overall, our study not only provide an optimized approach for PAP purification, but also offer crucial insights into its structural characteristics. These findings lay the groundwork for further investigations into the physiological function and potential therapeutic applications of this important protein.

In-Depth Glycoproteomic Assay of Urinary Prostatic Acid Phosphatase

Prostate-specific antigen (PSA) is a well-known clinical biomarker in prostate cancer (PCa) diagnosis, but a better test is still needed, as the serum-level-based PSA quantification exhibits limited specificity and comes with poor predictive value. Prior to PSA, prostatic acid phosphatase (PAP) was used, but it was replaced by PSA because PSA improved the early detection of PCa. Upon revisiting PAP and its glycosylation specifically, it appears to be a promising new biomarker candidate. Namely, previous studies have indicated that PAP glycoforms differ between PCa and non-PCa individuals. However, an in-depth characterization of PAP glycosylation is still lacking. In this study, we established an in-depth glycoproteomic assay for urinary PAP by characterizing both the micro- and macroheterogeneity of the PAP glycoprofile. For this purpose, PAP samples were analyzed by capillary electrophoresis coupled to mass spectrometry after affinity purification from urine and proteolytic digestion. The developed urinary PAP assay was applied on a pooled DRE (digital rectal examination) urine sample from nine individuals. Three glycosylation sites were characterized, namely N94, N220, and N333, via N-glycopeptide analysis. Taking sialic acid linkage isomers into account, a total of 63, 27, and 4 N-glycan structures were identified, respectively. The presented PAP glycoproteomic assay will enable the determination of potential glycomic biomarkers for the early detection and prognosis of PCa in cohort studies.

Aberrant Mannosylated and Highly Fucosylated Glycoepitopes of Prostatic Acid Phosphatase as Potential Ligands for Dendritic-Cell Specific ICAM-Grabbing Nonintegrin (DC-SIGN) in Human Seminal Plasma-A Step towards Explaining Idiopathic Infertility

Semen prostatic acid phosphatase (PAP) has been proposed as an endogenous ligand for dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN), which plays a critical immuno-modulating role in maintaining homeostasis in the female reproductive tracts. In the current study, we assumed that semen PAP bears a set of fucosylated and mannosylated glycans, which may mediate the efficient binding of PAP to DC-SIGN. To investigate this hypothesis, we developed ELISA assays using Galanthus nivalis and Lotus tetragonolobus lectins capable of binding mannose-containing glycans or LewisX and LewisY motifs, respectively. In our assay with Galanthus nivalis, we detected that the relative reactivity of PAP mannose-presenting glycans in the normozoospermic idiopathic group was significantly higher than in the asthenozoospermic, oligozoospermic and oligoasthenozoospermic groups. Simultaneously, we observed slight differences in the relative reactivities of PAP glycans with Lotus tetragonolobus lectin among groups of patients with abnormal semen parameters. Subsequently, we examined whether DC-SIGN interacts with seminal plasma PAP glycans, and we detected a significantly higher relative reactivity in the normozoospermic group compared to the oligozoospermic group. Finally, we concluded that the significantly aberrant abundance of mannosylated functional groups of PAP among patients with semen disorders can suggest that PAP may thereby be engaged in modulating the immune response and promoting a tolerogenic response to male antigens in the female reproductive system.

A meta-analysis of epitopes in prostate-specific antigens identifies opportunities and knowledge gaps

BACKGROUND

The Cancer Epitope Database and Analysis Resource (CEDAR) is a newly developed repository of cancer epitope data from peer-reviewed publications, which includes epitope-specific T cell, antibody, and MHC ligand assays. Here we focus on prostate cancer as our first cancer category to demonstrate the capabilities of CEDAR, and to shed light on the advances of epitope-related prostate cancer research.

RESULTS

The meta-analysis focused on a subset of data describing epitopes from 8 prostate-specific (PS) antigens. A total of 460 epitopes were associated with these proteins, 187 T cell, 109B cell, and 271 MHC ligand epitopes. The number of epitopes was not correlated with the length of the protein; however, we found a significant positive correlation between the number of references per specific PS antigen and the number of reported epitopes. Forty-four different class I and 27 class II restrictions were found, with the most epitopes described for HLA-A*02:01 and HLA-DRB1*01:01. Cytokine assays were mostly limited to IFNg assays and a very limited number of tetramer assays were performed. Monoclonal and polyclonal B cell responses were balanced, with the highest number of epitopes studied in ELISA/Western blot assays. Additionally, epitopes were generically described as associated with prostate cancer, with little granularity specifying diseases state. We found that in vivo and tumor recognition assays were sparse, and the number of epitopes with annotated B/T cell receptor information were limited. Potential immunodominant regions were identified by the use of the ImmunomeBrowser tool.

CONCLUSION

CEDAR provides a comprehensive repository of epitopes related to prostate-specific antigens. This inventory of epitope data with its wealth of searchable T cell, B cell and MHC ligand information provides a useful tool for the scientific community. At the same time, we identify significant knowledge gaps that could be addressed by experimental analysis.

Novel signatures of prostate cancer progression and therapeutic resistance

INTRODUCTION

The extensive heterogeneity of prostate cancer (PCa) and multilayered complexity of progression to castration-resistant prostate cancer (CRPC) have contributed to the challenges of accurately monitoring advanced disease. Profiling of the tumor microenvironment with large-scale transcriptomic studies have identified gene signatures that predict biochemical recurrence, lymph node invasion, metastases, and development of therapeutic resistance through critical determinants driving CRPC.

AREAS COVERED

This review encompasses understanding of the role of different molecular determinants of PCa progression to lethal disease including the phenotypic dynamic of cell plasticity, EMT-MET interconversion, and signaling-pathways driving PCa cells to advance and metastasize. The value of liquid biopsies encompassing circulating tumor cells and extracellular vesicles to detect disease progression and emergence of therapeutic resistance in patients progressing to lethal disease is discussed. Relevant literature was added from PubMed portal.

EXPERT OPINION

Despite progress in the tumor-targeted therapeutics and biomarker discovery, distant metastasis and therapeutic resistance remain the major cause of mortality in patients with advanced CRPC. No single signature can encompass the tremendous phenotypic and genomic heterogeneity of PCa, but rather multi-threaded omics-derived and phenotypic markers tailored and validated into a multimodal signature.

Intravenous administration of viral vectors expressing prostate cancer antigens enhances the magnitude and functionality of CD8+ T cell responses

BACKGROUND

The use of immunotherapeutic vaccination in prostate cancer is a promising approach that likely requires the induction of functional, cytotoxic T cells . The experimental approach described here uses a well-studied adenovirus-poxvirus heterologous prime-boost regimen, in which the vectors encode a combination of prostate cancer antigens, with the booster dose delivered by either the intravenous or intramuscular (IM) route. This prime-boost regimen was investigated for antigen-specific CD8+ T cell induction.

METHODS

The coding sequences for four antigens expressed in prostate cancer, 5T4, PSA, PAP, and STEAP1, were inserted into replication-incompetent chimpanzee adenovirus Oxford 1 (ChAdOx1) and into replication-deficient modified vaccinia Ankara (MVA). In four strains of mice, ChAdOx1 prime was delivered intramuscularly, with an MVA boost delivered by either IM or intravenous routes. Immune responses were measured in splenocytes using ELISpot, multiparameter flow cytometry, and a targeted in vivo killing assay.

RESULTS

The prime-boost regimen was highly immunogenic, with intravenous administration of the boost resulting in a sixfold increase in the magnitude of antigen-specific T cells induced and increased in vivo killing relative to the intramuscular boosting route. Prostate-specific antigen (PSA)-specific responses were dominant in all mouse strains studied (C57BL/6, BALBc, CD-1 and HLA-A2 transgenic).

CONCLUSION

This quadrivalent immunotherapeutic approach using four antigens expressed in prostate cancer induced high magnitude, functional CD8+ T cells in murine models. The data suggest that comparing the intravenous versus intramuscular boosting routes is worthy of investigation in humans.

Overcoming Immune Resistance With Radiation Therapy in Prostate Cancer

Prostate cancer is the second most common cancer in men and represents a significant healthcare burden worldwide. Therapeutic options in the metastatic castration-resistant setting remain limited, despite advances in androgen deprivation therapy, precision medicine and targeted therapies. In this review, we summarize the role of immunotherapy in prostate cancer and offer perspectives on opportunities for future development, based on current knowledge of the immunosuppressive tumor microenvironment. Furthermore, we discuss the potential for synergistic therapeutic strategies with modern radiotherapy, through modulation of the tumor microenvironment. Emerging clinical and pre-clinical data suggest that radiation can convert immune desert tumors into an inflamed immunological hub, potentially sensitive to immunotherapy.

Therapeutic Vaccines Targeting Neoantigens to Induce T-Cell Immunity against Cancers

Cancer immunotherapy has achieved multiple clinical benefits and has become an indispensable component of cancer treatment. Targeting tumor-specific antigens, also known as neoantigens, plays a crucial role in cancer immunotherapy. T cells of adaptive immunity that recognize neoantigens, but do not induce unwanted off-target effects, have demonstrated high efficacy and low side effects in cancer immunotherapy. Tumor neoantigens derived from accumulated genetic instability can be characterized using emerging technologies, such as high-throughput sequencing, bioinformatics, predictive algorithms, mass-spectrometry analyses, and immunogenicity validation. Neoepitopes with a higher affinity for major histocompatibility complexes can be identified and further applied to the field of cancer vaccines. Therapeutic vaccines composed of tumor lysates or cells and DNA, mRNA, or peptides of neoantigens have revoked adaptive immunity to kill cancer cells in clinical trials. Broad clinical applicability of these therapeutic cancer vaccines has emerged. In this review, we discuss recent progress in neoantigen identification and applications for cancer vaccines and the results of ongoing trials.

A Mutated Prostatic Acid Phosphatase (PAP) Peptide-Based Vaccine Induces PAP-Specific CD8+ T Cells with Ex Vivo Cytotoxic Capacities in HHDII/DR1 Transgenic Mice

BACKGROUND

Current treatments for castrate (hormone)-resistant prostate cancer (CRPC) remain limited and are not curative, with a median survival from diagnosis of 23 months. The PAP-specific Sipuleucel-T vaccine, which was approved by the FDA in 2010, increases the Overall Survival (OS) by 4 months, but is extremely expensive. We have previously shown that a 15 amino accid (AA) PAP sequence-derived peptide could induce strong immune responses and delay the growth of murine TRAMP-C1 prostate tumors. We have now substituted one amino acid and elongated the sequence to include epitopes predicted to bind to several additional HLA haplotypes. Herein, we present the immunological properties of this 42mer-mutated PAP-derived sequence (MutPAP42mer).

METHODS

The presence of PAP-135-143 epitope-specific CD8⁺ T cells in the blood of patients with prostate cancer (PCa) was assessed by flow cytometry using Dextramer™ technology. HHDII/DR1 transgenic mice were immunized with mutated and non-mutated PAP-derived 42mer peptides in the presence of CAF^®09 or CpG ODN1826 (TLR-9 agonist) adjuvants. Vaccine-induced immune responses were measured by assessing the proportion and functionality of splenic PAP-specific T cells in vitro.

RESULTS

PAP-135-143 epitope-specific CD8⁺ T cells were detected in the blood of patients with PCa and stimulation of PBMCs from patients with PCa with mutPAP42mer enhanced their capacity to kill human LNCaP PCa target cells expressing PAP. The MutPAP42mer peptide was significantly more immunogenic in HHDII/DR1 mice than the wild type sequence, and immunogenicity was further enhanced when combined with the CAF^®09 adjuvant. The vaccine induced secretory (IFNγ and TNFα) and cytotoxic CD8⁺ T cells and effector memory splenic T cells.

CONCLUSIONS

The periphery of patients with PCa exhibits immune responsiveness to the MutPAP42mer peptide and immunization of mice induces/expands T cell-driven, wild-type PAP immunity, and therefore, has the potential to drive protective anti-tumor immunity in patients with PCa.

Recessive Mutations in ACP4 Cause Amelogenesis Imperfecta

Amelogenesis imperfecta (AI) is an innate disorder that affects the formation and mineralization of the tooth enamel. When diagnosed with AI, one's teeth can be hypoplastic (thin enamel), hypomature (normal enamel thickness but discolored and softer than normal enamel), hypocalcified (normal enamel thickness but extremely weak), or mixed conditions of the above. Numerous studies have revealed the genes that are involved in causing AI. Recently, ACP4 (acid phosphatase 4) was newly found as a gene causing hypoplastic AI, and it was suggested that mutant forms of ACP4 might affect access to the catalytic core or the ability to form a homodimer. In this study, a Korean and a Turkish family with hypoplastic AI were recruited, and their exome sequences were analyzed. Biallelic mutations were revealed in ACP4: paternal (NM_033068: c.419C>T, p.(Pro140Leu)) and maternal (c.262C>A, p.(Arg88Ser)) mutations in family 1 and a paternal (c.713C>T, p.(Ser238Leu)) mutation and de novo (c.350A>G, p.(Gln117Arg)) mutation in the maternal allele in family 2. Mutations were analyzed by cloning, mutagenesis, immunofluorescence, immunoprecipitation, and acid phosphatase activity test. Comparison between the wild-type and mutant ACP4s showed a decreased amount of protein expression from the mutant forms, a decreased ability to form a homodimer, and a decreased acid phosphatase activity level. We believe that these findings will not only expand the mutational spectrum of ACP4 but also increase our understanding of the mechanism of ACP4 function during normal and pathologic amelogenesis.

Integration of Single-Cell RNA- and CAGE-seq Reveals Tooth-Enriched Genes

Organ development is dictated by the regulation of genes preferentially expressed in tissues or cell types. Gene expression profiling and identification of specific genes in organs can provide insights into organogenesis. Therefore, genome-wide analysis is a powerful tool for clarifying the mechanisms of development during organogenesis as well as tooth development. Single-cell RNA sequencing (scRNA-seq) is a suitable tool for unraveling the gene expression profile of dental cells. Using scRNA-seq, we can obtain a large pool of information on gene expression; however, identification of functional genes, which are key molecules for tooth development, via this approach remains challenging. In the present study, we performed cap analysis of gene expression sequence (CAGE-seq) using mouse tooth germ to identify the genes preferentially expressed in teeth. The CAGE-seq counts short reads at the 5'-end of transcripts; therefore, this method can quantify the amount of transcripts without bias related to the transcript length. We hypothesized that this CAGE data set would be of great help for further understanding a gene expression profile through scRNA-seq. We aimed to identify the important genes involved in tooth development via bioinformatics analyses, using a combination of scRNA-seq and CAGE-seq. We obtained the scRNA-seq data set of 12,212 cells from postnatal day 1 mouse molars and the CAGE-seq data set from postnatal day 1 molars. scRNA-seq analysis revealed the spatiotemporal expression of cell type-specific genes, and CAGE-seq helped determine whether these genes are preferentially expressed in tooth or ubiquitously. Furthermore, we identified candidate genes as novel tooth-enriched and dental cell type-specific markers. Our results show that the integration of scRNA-seq and CAGE-seq highlights the genes important for tooth development among numerous gene expression profiles. These findings should contribute to resolving the mechanism of tooth development and establishing the basis for tooth regeneration in the future.

Multifunctionality of prostatic acid phosphatase in prostate cancer pathogenesis

The role of human prostatic acid phosphatase (PAcP, P15309|PPAP_HUMAN) in prostate cancer was investigated using a new proteomics tool termed signal sequence swapping (replacement of domains from the native cleaved amino terminal signal sequence of secretory/membrane proteins with corresponding regions of functionally distinct signal sequence subtypes). This manipulation preferentially redirects proteins to different pathways of biogenesis at the endoplasmic reticulum (ER), magnifying normally difficult to detect subsets of the protein of interest. For PAcP, this technique reveals three forms identical in amino acid sequence but profoundly different in physiological functions, subcellular location, and biochemical properties. These three forms of PAcP can also occur with the wildtype PAcP signal sequence. Clinical specimens from patients with prostate cancer demonstrate that one form, termed ^PLPAcP, correlates with early prostate cancer. These findings confirm the analytical power of this method, implicate ^PLPAcP in prostate cancer pathogenesis, and suggest novel anticancer therapeutic strategies.

Alterations in protein expression and site-specific N-glycosylation of prostate cancer tissues

Identifying molecular alterations occurring during cancer progression is essential for a deeper understanding of the underlying biological processes. Here we have analyzed cancerous and healthy prostate biopsies using nanoLC-MS(MS) to detect proteins with altered expression and N-glycosylation. We have identified 75 proteins with significantly changing expression during disease progression. The biological processes involved were assigned based on protein-protein interaction networks. These include cellular component organization, metabolic and localization processes. Multiple glycoproteins were identified with aberrant glycosylation in prostate cancer, where differences in glycosite-specific sialylation, fucosylation, and galactosylation were the most substantial. Many of the glycoproteins with altered N-glycosylation were extracellular matrix constituents, and are heavily involved in the establishment of the tumor microenvironment.

Redox State and Lysosomal Activity in Women with Ovarian Cancer with Tumor Recurrence and Multiorgan Metastasis

The aim of the study is to evaluate oxidant-antioxidant balance as well as lysosomal and anti-protease activities in ovarian cancer since it has been emphasized that the crucial inducing factor of carcinogenesis may be reactive oxygen/nitrogen species or, more precisely, oxidative stress-induced inflammation. The study involved 15 women with ovarian cancer, aged 59.9 ± 7.8 years, and 9 healthy women aged 56.3 ± 4.3 years (controls). The study material was venous blood collected from fasting subjects. In erythrocytes, the activities of superoxide dismutase, glutathione peroxidase, and catalase, as well as concentrations of conjugated dienes (CDs) and thiobarbituric acid reactive substances (TBARS), were investigated. CD, TBARS, and vitamins A and E plasma concentrations were also determined. Moreover, total antioxidant capacity and concentrations of 4-hydroxynonenal adducts and 8-iso-prostaglandin F2α, as well as activities of acid phosphatase, arylsulfatase, cathepsin D, and α₁-antitrypsin, were studied in serum. The vitamin E and 8-iso-prostaglandin F2α concentrations as well as arylsulfatase activity were lower in the women with cancer compared to the controls (p = 0.006, p = 0.03, p = 0.001, respectively). In contrast, cathepsin D activity was lower in the controls (p = 0.04). In the peripheral blood of the women with cancer, oxidant-antioxidant and lysosomal disturbances were observed.

Prostate Cancer Immunotherapy-Finally in From the Cold?

PURPOSE OF REVIEW

Despite significant progress, patients with metastatic prostate cancer continue to have poor prognosis. Immunotherapy has revolutionized cancer care for many tumor types but has a limited role in the treatment of prostate cancer. This review discusses the promise of immunotherapy in prostate cancer treatment with an emphasis on emerging therapeutic targets.

RECENT FINDINGS

Most prostate tumors have low tumor mutational burden and lack immunogenicity, representing significant hurdles to induction of anti-tumor immunity. However, recent research centered on deciphering key mechanisms of immune resistance in the prostate tumor microenvironment has led to the discovery of a range of new treatment targets. These discoveries are currently being translated into innovative immunotherapy clinical trials for patients with prostate cancer. Recent progress includes early evidence of activity for these novel approaches and the identification of potential predictive biomarkers of response. Novel treatment strategies using new antigen-directed therapies, drugs targeting the immunosuppressive tumor microenvironment, and combination immunotherapy therapies show great potential and are currently in clinical development. In addition, a deeper understanding of predictors of response and resistance to immunotherapy in prostate cancer is allowing for a more personalized approach to therapy.

Evolution of Cancer Vaccines-Challenges, Achievements, and Future Directions

The development of cancer vaccines has been intensively pursued over the past 50 years with modest success. However, recent advancements in the fields of genetics, molecular biology, biochemistry, and immunology have renewed interest in these immunotherapies and allowed the development of promising cancer vaccine candidates. Numerous clinical trials testing the response evoked by tumour antigens, differing in origin and nature, have shed light on the desirable target characteristics capable of inducing strong tumour-specific non-toxic responses with increased potential to bring clinical benefit to patients. Novel delivery methods, ranging from a patient’s autologous dendritic cells to liposome nanoparticles, have exponentially increased the abundance and exposure of the antigenic payloads. Furthermore, growing knowledge of the mechanisms by which tumours evade the immune response has led to new approaches to reverse these roadblocks and to re-invigorate previously suppressed anti-tumour surveillance. The use of new drugs in combination with antigen-based therapies is highly targeted and may represent the future of cancer vaccines. In this review, we address the main antigens and delivery methods used to develop cancer vaccines, their clinical outcomes, and the new directions that the vaccine immunotherapy field is taking.

Can conventional clinical chemistry tests help doctors in the monitoring of oncology patients?

The use of laboratory assays in the diagnostic care of oncology patients can markedly increase the efficacy of cancer treatments. Many cancer-specific biomarker assays have been developed. However, the use of these has some limitations due to their cost. Moreover, not every diagnostic laboratory can perform a complete set of these assays. On the other hand, the smart use of conventional clinical chemistry tests could improve the management of cancer. They could be especially valuable tools in the long-term care of patients with a verified diagnosis. In this review, we discuss the utilization of the conventional clinical chemistry assays for the diagnosis, monitoring and prognosis of various oncological diseases. The use of conventional blood tests to assess the levels of chemical elements, metabolites and proteins (including enzymatic activity measurements) in the care of oncology patients is discussed. We have shown that some clinical chemistry assays could be used in the management of distinct kinds of cancer.

Rapid identification of magnesium ascorbyl phosphate utilizing phosphatase through a chromogenic change-coupled activity assay

In this study, we report a chromogenic reaction between magnesium ascorbyl phosphate (MAP) and ferric chloride to generate a Brown-Red clathrate, while the Treated MAP by phosphatases forms Colorless (BRTC) product with ferric chloride. The BRTC was indicative of phosphatase activity-mediated excision of phosphorous group from MAP and utilized to screen phosphatases from bacterial cell lysates. From ten tested strains, BRTC was observed in the cell lysate of Salmonella enterica subsp. enterica serovar Cerro 87. BRTC was again employed to track phosphatase activity of the resuspensions of the ammonium sulfate graded precipitations of the cell lysate. Two phosphatases, PhoN and YcdX, were identified by LC-MS/MS analysis in the protein fraction giving most obvious BRTC phenotype and validated by examination of in vitro activity of the purified proteins. KEY POINTS: • BRTC is labelling-free, naked-eye visible, and independent of any facilities. • BRTC can directly screen phosphatases from microbial cell lysates. • Using BRTC system, two phosphatases were identified in Salmonella enterica subsp. enterica serovar Cerro 87.

Convergent network effects along the axis of gene expression during prostate cancer progression

Background

Tumor-specific genomic aberrations are routinely determined by high-throughput genomic measurements. It remains unclear how complex genome alterations affect molecular networks through changing protein levels and consequently biochemical states of tumor tissues.

Results

Here, we investigate the propagation of genomic effects along the axis of gene expression during prostate cancer progression. We quantify genomic, transcriptomic, and proteomic alterations based on 105 prostate samples, consisting of benign prostatic hyperplasia regions and malignant tumors, from 39 prostate cancer patients. Our analysis reveals the convergent effects of distinct copy number alterations impacting on common downstream proteins, which are important for establishing the tumor phenotype. We devise a network-based approach that integrates perturbations across different molecular layers, which identifies a sub-network consisting of nine genes whose joint activity positively correlates with increasingly aggressive tumor phenotypes and is predictive of recurrence-free survival. Further, our data reveal a wide spectrum of intra-patient network effects, ranging from similar to very distinct alterations on different molecular layers.

Conclusions

This study uncovers molecular networks with considerable convergent alterations across tumor sites and patients. It also exposes a diversity of network effects: we could not identify a single sub-network that is perturbed in all high-grade tumor regions.

Amyloid-Like Peptide Aggregates

Self-assembly of proteins and peptides into the amyloid fold is a widespread phenomenon in the natural world. The structural hallmark of self-assembly into amyloid fibrillar assemblies is the cross-beta motif, which conveys distinct morphological and mechanical properties. The amyloid fibril formation has contrasting results depending on the organism, in the sense that it can bestow an organism with the advantages of mechanical strength and improved functionality or, on the contrary, could give rise to pathological states. In this chapter we review the existing information on amyloid-like peptide aggregates, which could either be derived from protein sequences, but also could be rationally or de novo designed in order to self-assemble into amyloid fibrils under physiological conditions. Moreover, the development of self-assembled fibrillar biomaterials that are tailored for the desired properties towards applications in biomedical or environmental areas is extensively analyzed. We also review computational studies predicting the amyloid propensity of the natural amino acid sequences and the structure of amyloids, as well as designing novel functional amyloid materials.

Mechanistic insights of host cell fusion of SARS-CoV-1 and SARS-CoV-2 from atomic resolution structure and membrane dynamics

The emerging and re-emerging viral diseases are continuous threats to the wellbeing of human life. Previous outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS had evidenced potential threats of coronaviruses in human health. The recent pandemic due to SARS-CoV-2 is overwhelming and has been going beyond control. Vaccines and antiviral drugs are ungently required to mitigate the pandemic. Therefore, it is important to comprehend the mechanistic details of viral infection process. The fusion between host cell and virus being the first step of infection, understanding the fusion mechanism could provide crucial information to intervene the infection process. Interestingly, all enveloped viruses contain fusion protein on their envelope that acts as fusion machine. For coronaviruses, the spike or S glycoprotein mediates successful infection through receptor binding and cell fusion. The cell fusion process requires merging of virus and host cell membranes, and that is essentially performed by the S2 domain of the S glycoprotein. In this review, we have discussed cell fusion mechanism of SARS-CoV-1 from available atomic resolution structures and membrane binding of fusion peptides. We have further discussed about the cell fusion of SARS-CoV-2 in the context of present pandemic situation.

Urinary Reference Values and First Insight into the Urinary Proteome of Captive Giraffes

Urinalysis is widely recognized to be a useful tool in routine health investigations, since it can diagnose numerous pathologies. Considering the paucity of knowledge concerning giraffes, urine from 44 giraffes (Giraffa camelopardalis) (18 males and 26 females, from 3 months of age to 21 years of age) underwent routine urinalysis, 1D-electrophoresis, and protein identification using mass spectrometry, with the aim of identifying the urinary reference values and the urine proteome. The urine specific gravity (USG), urine total proteins (uTP), urine creatinine (uCr), and urine protein:creatinine ratio (UPC) reference values, reported as the median, and lower limit (LL) and upper limit (UL), were 1.030 (1006-1.049), 17.58 (4.54-35.31) mg/dL, 154.62 (39.59-357.95) mg/dL, and 0.11 (0.07-0.16), respectively. Mass spectrometry, together with electrophoresis, revealed a pattern of common urinary proteins; albumin, lysozyme C, and ubiquitin were the most represented proteins in the giraffe urine. It has been hypothesized that these proteins could act as a defense against microbes. Moreover, in giraffes, urinalysis could be a valid tool for gauging renal function and physiological status changes.

Targeting Metabolism of Extracellular Nucleotides via Inhibition of Ectonucleotidases CD73 and CD39

In the tumor microenvironment, unusually high concentrations of extracellular adenosine promote tumor proliferation through various immunosuppressive mechanisms. Blocking adenosine production by inhibiting nucleotide-metabolizing enzymes, such as ectonucleotidases CD73 and CD39, represents a promising therapeutic strategy that may synergize with other immuno-oncology mechanisms and chemotherapies. Emerging small-molecule ectonucleotidase inhibitors have recently entered clinical trials. This Perspective will outline challenges, strategies, and recent advancements in targeting this class with small-molecule inhibitors, including AB680, the first small-molecule CD73 inhibitor to enter clinical development. Specific case studies, including structure-based drug design and lead optimization, will be outlined. Preclinical data on these molecules and their ability to enhance antitumor immunity will be discussed.

Antibody-drug conjugates, cancer immunotherapy, and metronomic chemotherapy as novel approaches in cancer management

Treatment of cancer is a major challenge even though the pathophysiology is becoming clearer with time. A number of new chemical entities are developed to target cancer growth inhibition, but the targeted delivery of these products still needs novel research. This is of utmost importance not only for higher efficacy but also for a reduction in systemic toxicity and cost of treatment. Although multiple novel targets and molecules are being researched, most of them could not pass the regulatory approval process, due to low benefit-risk ratio and lack of target specificity. Failure of a majority of these drugs was in part due to their superiority claimed via surrogate markers. Despite these, currently, more than 100 chemotherapeutic agents are in practice. This review paper discusses in detail the molecular basis, drug discovery, and pros and cons over conventional treatment approaches of three novel approaches in cancer therapy, i.e., (i) antibody-drug conjugates, (ii) cancer immunotherapy, and (iii) metronomic chemotherapy. All the drugs developed using these three novel approaches were compared against the established treatment regimens in clinical trials with clinical end points, such as overall survival, progression-free survival, and quality of life.

The Impact of Modern Therapeutic Methods on the Oxidant-Antioxidant Equilibrium and Activities of Selected Lysosomal Enzymes and Serine Protease Inhibitor in Amateur Athletes

Deep electromagnetic stimulation (DEMS) and low-frequency ultrasound (US) are new physical therapy methods used in the rehabilitation of the musculoskeletal system and wound healing. They are applied locally to treat the injured tissues. The beneficial effects of these methods in supportive care have been documented, but accurate biochemical effects are not known. The goal was to assess the effect of single DEMS and US sessions on the oxidant-antioxidant equilibrium, as well as the activities of lysosomal hydrolases and α ₁-antitrypsin (AAT) in peripheral blood of juvenile injured amateur athletes. In the athletes with low back pain (DEMS treated, N = 16) and pain in the shoulder or ankle joint (US treated, N = 14), as well as in healthy control amateur athletes (DEMS treated, N = 14; US treated, N = 17), before the sessions and 30 minutes and 24 hours after them, the levels of the following parameters were determined: thiobarbituric acid reactive substances (TBARS) in erythrocytes and plasma, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in erythrocytes, as well as acid phosphatase (AcP), arylsulfatase (ASA), cathepsin D (CTS D), and α ₁-antitrypsin (AAT) in serum. After both procedures, the levels of parameters changed in a negligible manner, excluding the cathepsin D activity, which was statistically significantly lower 30 min and 24 h after US in the control athletes compared to the baseline activity determined directly before the procedure (47.5% and 55.7% differences, respectively). Similar tendency was observed after DEMS (p > 0.05). The procedures, especially low-frequency US, decrease lysosomal proteolytic activity and do not significantly disrupt the oxidant-antioxidant and lysosomal equilibriums in the peripheral blood both of healthy and injured athletes. No systemic acute-phase response of AAT was also detected in the athletes after both procedures. This trial is registered with CTRI/2018/01/011344.

Cold-hearted: A case for cold stress in cancer risk

A negative correlation exists between environmental temperature and cancer risk based on both epidemiological and statistical analyses. Previously, cold stress was reported to be an effective cause of tumorigenesis. Several studies have demonstrated that cold temperature serves as a potential risk factor in cancer development. Most recently, a link was demonstrated between the effects of extreme cold climate on cancer incidence, pinpointing its impact on tumour suppressor genes by causing mutation. The underlying mechanism behind cold stress and its association with tumorigenesis is not well understood. Hence, this review intends to shed light on the role of associated factors, genetic and/or non-genetic, which are modulated by cold temperature, and eventually influence tumorigenic potential. While scrutinizing the effect of cold exposure on the body, the expression of certain genes, e.g. uncoupled proteins and heat-shock proteins, were elevated. Biological chemicals such as norepinephrine, thyroxine, and cholesterol were also elevated. Brown adipose tissue, which plays an essential role in thermogenesis, displayed enhanced activity upon cold exposure. Adaptive measures are utilized by the body to tolerate the cold, and in doing so, invites both epigenetic and genetic changes. Unknowingly, these adaptive strategies give rise to a lethal outcome i.e., genesis of cancer. Concisely, this review attempts to draw a link between cold stress, genetic and epigenetic changes, and tumorigenesis and aspires to ascertain the mechanism behind cold temperature-mediated cancer risk.

Protocatechuic acid ameliorates testosterone-induced benign prostatic hyperplasia through the regulation of inflammation and oxidative stress in castrated rats

Protocatechuic acid (PA) is a polyphenol-recognized for its efficacy as an antioxidant-possesses anticancer, anti-inflammatory, antioxidant properties. The efficacy of PA in the management of benign prostatic hyperplasia (BPH) has not been investigated. Forty-two castrated rats (n = 7) were treated as follows: control (corn oil), BPH only received testosterone propionate (TP) (TP 3 mg/kg intraperitoneally), BPH + PA (TP 3 mg/kg + PA 40 mg/kg), BPH + finasteride (Fin) (TP 3 mg/kg + Fin 10 mg/kg), PA only (40 mg/kg: by gavage), and Fin only (10 mg/kg: by gavage) for 4 weeks. In BPH rats, there were significant (P < .05) increases in prostatic (250%) and organosomatic (280%) weights compared with controls. Cotreatment decreased prostatic weights by 19% (PA) and 21% (Fin). Markers of inflammation: myeloperoxidase activities increased in serum (148%) and prostate (70%), as well as nitric oxide levels serum (92%) and prostatic (95%). Proinflammatory cytokines interleukin-1β and tumor necrosis factor-α increased by 3.6- and 2.8-fold. Furthermore, prostatic malondialdehyde, superoxide dismutase, and serum total acid phosphatase increased by 97%, 25%, and 48%, respectively. Histology revealed poor architecture and severe proliferation of the prostate in BPH rats. Inflammation and oxidative stress markers, as well as the histological alteration in BPH rats, was attenuated (P < .05) upon cotreatment with PA and comparable with Fin cotreatment. These results suggest that PA mitigates oxido-inflammatory responses and restored prostatic cytoarchitecture to levels comparable with control in rats induced with BPH.

Immunological Complexity of the Prostate Cancer Microenvironment Influences the Response to Immunotherapy

Prostate cancer is one of the most common cancers in men and a leading cause of cancer-related death. Recent advances in the treatment of advanced prostate cancer, including the use of more potent and selective inhibitors of the androgen signaling pathway, have provided significant clinical benefit for men with metastatic castration-resistant prostate cancer (mCRPC). However, most patients develop progressive lethal disease, highlighting the need for more effective treatments. One such approach is immunotherapy, which harness the power of the patient's immune system to identify and destroy cancer cells through the activation of cytotoxic CD8 T cells specific for tumor antigens. Although immunotherapy, particularly checkpoint blockade, can induce significant clinical responses in patients with solid tumors or hematological malignancies, minimal efficacy has been observed in men with mCRPC. In the current review, we discuss our current understanding of the immunological complexity of the immunosuppressive prostate cancer microenvironment, preclinical models of prostate cancer, and recent advances in immunotherapy clinical trials to improve outcomes for men with mCRPC.

The impact of high-intensity laser therapy on oxidative stress, lysosomal enzymes, and protease inhibitor in athletes

The aim of the study was to assess the effect of one session of high-intensity laser therapy (HILT) on the levels of selected oxidative stress parameters, lysosomal hydrolases, and anti-inflammatory serine protease inhibitor in the peripheral blood of amateur athletes with torn or pulled tendons of the ankle or the knee joint. The group of injured athletes comprised 16 males and females aged 16.3 ± 1.3 years, while the control group of 14 healthy, noninjured amateur athletes of both sexes (controls; age 17.4 ± 4.6 years). Material for the study was peripheral blood taken at three study time points: Immediately before, 30 min after, and 24 h after HILT intervention. In plasma and erythrocytes, thiobarbituric acid reactive substances (TBARSpl and TBARSer, respectively) were determined. In erythrocytes, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured. In serum, the activity of acid phosphatase (AcP), arylsulfatase (ASA), cathepsin D (CTS D), and α1-antitrypsin (AAT) were determined. Among oxidative stress parameters, only the CAT activity significantly decreased 24 h after HILT compared to measurement 30 min after the treatment in the injured individuals (P < 0.01), while the GPx activity in that group was meaningfully higher 30 min after HILT compared to controls (P < 0.05). Thirty min after the intervention, the activities of AcP and ASA were lower in the injured participants compared to the uninjured ones (P < 0.01 and P < 0.05, respectively). The CTS D activity was lower 30 min and 24 h after HILT in both groups (P < 0.001) and did not differ significantly between them (P > 0.05). Moreover, the study showed statistically significant linear relationships between the TBARSer concentration and the SOD activity before HILT in the healthy participants (r = -0.6, P = 0.021) and 24 h after HILT in the injured ones (r = 0.6, P = 0.025). In the noninjured athletes before HILT, the CTS D activity linearly correlated with the AAT activity (r = -0.70, P = 0.005), and 30 min after the treatment, with the AcP activity (r = 0.5, P = 0.041). 24 h after the HILT intervention, the CTS D and AcP activities were also correlated in the injured athletes (r = 0.8, P = 0.002). The study suggests that one HILT intervention does not significantly influence the redox equilibrium but stabilizes lysosomal membranes.

Diagnostic value of acid phosphatases (ACP) in differentiating reactive mesothelial cells from cancer cells in the body fluid effusions

Background

The cytological diagnosis of a malignant epithelial tumor, i.e., a cancer cell in the body fluid effusions is usually made by cytomorphological examination alone; however, diagnostic challenges can occur when the cancer cells are rare or cytological atypia is minimal. Morphological similarity between the cancer and the reactive mesothelial cell is the most common problem in establishing a clear diagnosis. The aim of this study is to investigate whether the cocktail acid phosphatases (ACP) special staining will be a useful tumor marker in differentiation of the reactive mesothelial cells from the cancer cells in the body fluid effusions.

Methods

The cocktail ACP special staining was performed on 212 body fluid effusion samples, which included 128 pleural effusions, 69 ascites, and 15 pericardial effusions.

Results

The mesothelial cells were cocktail ACP positive in 84 out of 84 benign effusion cases, and the sensitivity and the specificity were 100% for the benign effusions which including pleural effusions, ascites, and pericardial effusions. On the other hand, 122 out of 128 cancer cases were cocktail ACP negative, indicating that the sensitivity of using the cocktail ACP staining to rule out the malignant effusions was 95.3%. Thus, the cocktail ACP staining is an excellent marker with high sensitivity and specificity to distinguish the carcinoma from the reactive mesothelial cells in the body fluid effusions.

Conclusions

Our finding provided a new tool for cytopathologists in diagnosing the body fluid effusion that could impact clinical decision making.

Semen-derived amyloidogenic peptides-Key players of HIV infection

Misfolding and amyloid aggregation of intrinsically disordered proteins (IDPs) are implicated in a variety of diseases. Studies have shown that membrane plays important roles on the formation of intermediate structures of IDPs that can initiate (and/or speed-up) amyloid aggregation to form fibers. The process of amyloid aggregation also disrupts membrane to cause cell death in amyloid diseases like Alzheimer's disease and type-2 diabetes. On the other hand, recent studies reported the membrane fusion properties of amyloid fibers. Remarkably, amyloid-fibril formation by short peptide fragments of highly abundant prostatic acidic-phosphatase (PAP) in human semen and are capable of boosting the rate of HIV infection up to 400,000-fold during sexual contact. Unlike the least toxic fully matured fibers of most amyloid proteins, the semen-derived enhancer of virus infection (SEVI) amyloid-fibrils of PAP peptide fragments are highly potent in rendering the maximum rate of HIV infection. This unusual property of amyloid fibers has witnessed increasing number of studies on the biophysical aspects of fiber formation and fiber-membrane interactions. NMR studies have reported a highly disordered partial helical structure in a membrane environment for the intrinsically disordered PAP peptide that promotes the fusion of the viral membrane with that of host cells. The purpose of this review article is to unify and integrate biophysical and immunological research reported in the previous studies on SEVI. Specifically, amyloid aggregation, dramatic HIV infection enhancing properties, membrane fusion properties, high resolution NMR structure, and approaches to eliminate the enhancement of HIV infection of SEVI peptides are discussed.

Advances in development of new tools for the study of phosphohistidine

Protein phosphorylation is an important post-translational modification that is an integral part of cellular function. The O-phosphorylated amino-acid residues, such as phosphoserine (pSer), phosphothreonine (pThr) and phosphotyrosine (pTyr), have dominated the literature while the acid labile N-linked phosphorylated amino acids, such as phosphohistidine (pHis), have largely been historically overlooked because of the acidic conditions routinely used in amino-acid detection and analysis. This review highlights some misinterpretations that have arisen in the existing literature, pinpoints outstanding questions and potential future directions to clarify the role of pHis in mammalian signalling systems. Particular emphasis is placed on pHis isomerization and the hybrid functionality for both pHis and pTyr of the proposed τ-pHis analogue bearing the triazole residue.

Sipuleucel-T for the treatment of prostate cancer: novel insights and future directions

Sipuleucel-T, an autologous cellular immunotherapy manufactured from antigen-presenting cells primed to recognize prostatic acid phosphatase, was the first immunotherapy product approved by the US FDA. It was approved for men with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer after it was shown to provide a survival advantage. Additional studies have examined its use in other clinical settings and in combination with other approved and investigational immunotherapy agents. This review will discuss the pivotal trials leading to approval, will outline some of the biomarkers associated with its efficacy and will review some of the ongoing combination strategies. Maximizing the efficacy of sipuleucel-T through better patient selection or through combination approaches remains the challenge of the future.

A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland

Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent.

Determination of Glycoproteins by a Self-Assembled 4-Mercaptophenylboronic Acid Film on a Quartz Crystal Microbalance

Glycosylation plays an important part in many biological processes. However, many glycoproteins are either of low abundance or covered by other components in biological samples. Hence, developing new methods to measure the glycoproteins with both high efficiency and low detection limit is important. In this work, a self-assembled 4-mercaptophenylboronic acid film was coated on a quartz crystal microbalance chip. By optimizing the reaction time and the concentration of 4-mercaptophenylboronic acid, a sensor that specifically responded to glycoproteins was created. Then, several parameters for the prepared sensor were investigated and the working curve for representative glycoprotein-transferrin was established. The linearity range was from 50 to 400 ng/mL and the detection limit was 21.0 ng/mL. The sensor was used to detect transferrin in artificial urine samples. This sensor has a low detection limit of glycoproteins requiring only a small amount of samples, and thus has potential applications in both pharmaceutical and medical areas.

Veterinary Forensic Pathology of Animal Sexual Abuse

Animal sexual abuse (ASA) involves harm inflicted on animals for the purposes of human sexual gratification and includes such terms as bestiality, zoophilia, zoosadism, animal sexual assault, and others. The prevalence of ASA is not known, although it may be more common than is currently perceived. Veterinarians have the skills required to identify and document cases of ASA. This article reviews the terminology, legal definitions and forms of ASA, and its social and psychological context. An investigative approach is outlined, including an alternate light source examination; collection of swabs for DNA analysis; sampling vaginal washes, rectal washes, and toenails for trace evidence and biologic analyses; radiographic studies; and a complete forensic necropsy, including histopathology. Gross lesions identified in ASA victims include injuries to the anus, rectum, penis, scrotum, nipples, and vagina; the presence of foreign bodies; and abrasions, bruising, and other evidence of nonaccidental injury. Specialized procedures, including examination using alternate light sources and screening tests to identify human seminal fluid within samples from ASA victims, are of potential value but have not been validated for use in animals.

Characterization of parasite-specific indels and their proposed relevance for selective anthelminthic drug targeting

Insertions and deletions (indels) are important sequence variants that are considered as phylogenetic markers that reflect evolutionary adaptations in different species. In an effort to systematically study indels specific to the phylum Nematoda and their structural impact on the proteins bearing them, we examined over 340,000 polypeptides from 21 nematode species spanning the phylum, compared them to non-nematodes and identified indels unique to nematode proteins in more than 3000 protein families. Examination of the amino acid composition revealed uneven usage of amino acids for insertions and deletions. The amino acid composition and cost, along with the secondary structure constitution of the indels, were analyzed in the context of their biological pathway associations. Species-specific indels could enable indel-based targeting for drug design in pathogens/parasites. Therefore, we screened the spatial locations of the indels in the parasite's protein 3D structures, determined the location of the indel and identified potential unique drug targeting sites. These indels could be confirmed by RNA-Seq data. Examples are presented illustrating the close proximity of some indels to established small-molecule binding pockets that can potentially facilitate selective targeting to the parasites and bypassing their host, thus reducing or eliminating the toxicity of the potential drugs. This study presents an approach for understanding the adaptation of pathogens/parasites at a molecular level, and outlines a strategy to identify such nematode-selective targets that remain essential to the organism. With further experimental characterization and validation, it opens a possible channel for the development of novel treatments with high target specificity, addressing both host toxicity and resistance concerns.

Trichoderma harzianum Produces a New Thermally Stable Acid Phosphatase, with Potential for Biotechnological Application

Acid phosphatases (ACPases) are produced by a variety of fungi and have gained attention due their biotechnological potential in industrial, diagnosis and bioremediation processes. These enzymes play a specific role in scavenging, mobilization and acquisition of phosphate, enhancing soil fertility and plant growth. In this study, a new ACPase from Trichoderma harzianum, named ACPase II, was purified and characterized as a glycoprotein belonging to the acid phosphatase family. ACPase II presents an optimum pH and temperature of 3.8 and 65 °C, respectively, and is stable at 55 °C for 120 min, retaining 60% of its activity. The enzyme did not require metal divalent ions, but was inhibited by inorganic phosphate and tungstate. Affinity for several phosphate substrates was observed, including phytate, which is the major component of phosphorus in plant foods. The inhibition of ACPase II by tungstate and phosphate at different pH values is consistent with the inability of the substrate to occupy its active site due to electrostatic contacts that promote conformational changes, as indicated by fluorescence spectroscopy. A higher affinity for tungstate rather than phosphate at pH 4.0 was observed, in accordance with its highest inhibitory effect. Results indicate considerable biotechnological potential of the ACPase II in soil environments.

Selective extraction of bioactive glycoprotein in neutral environment through Concanavalin A mediated template immobilization and dopamine surface imprinting

Inspired by the sugar–lectin interaction, Concanavalin A mediated glycoprotein pre-immobilization, combined with dopamine polymerization, is employed to fabricate a glycoprotein imprint that can work in physiological environments.

Use of Aleuria alantia Lectin Affinity Chromatography to Enrich Candidate Biomarkers from the Urine of Patients with Bladder Cancer

Developing a urine test to detect bladder tumours with high sensitivity and specificity is a key goal in bladder cancer research. We hypothesised that bladder cancer-specific glycoproteins might fulfill this role. Lectin-ELISAs were used to study the binding of 25 lectins to 10 bladder cell lines and serum and urine from bladder cancer patients and non-cancer controls. Selected lectins were then used to enrich glycoproteins from the urine of bladder cancer patients and control subjects for analysis by shotgun proteomics. None of the lectins showed a strong preference for bladder cancer cell lines over normal urothlelial cell lines or for urinary glycans from bladder cancer patients over those from non-cancer controls. However, several lectins showed a strong preference for bladder cell line glycans over serum glycans and are potentially useful for enriching glycoproteins originating from the urothelium in urine. Aleuria alantia lectin affinity chromatography and shotgun proteomics identified mucin-1 and golgi apparatus protein 1 as proteins warranting further investigation as urinary biomarkers for low-grade bladder cancer. Glycosylation changes in bladder cancer are not reliably detected by measuring lectin binding to unfractionated proteomes, but it is possible that more specific reagents and/or a focus on individual proteins may produce clinically useful biomarkers.

[Identification of thiamine monophosphate hydrolyzing enzymes in chicken liver]

In animals, thiamine monophosphate (TMP) is an intermediate on the path of thiamine diphosphate, the coenzyme form of vitamin B1, degradation. The enzymes involved in TMP metabolism in animal tissues are not identified hitherto. The aim of this work was to study TMP hydrolysis in chicken liver. Two phosphatases have been found to contribute to TMP hydrolysis in liver homogenate. The first one, possessing a maximal activity at pH 6.0, is soluble, whereas the second one represents a membrane-bound enzyme with a pH optimum of 9.0. Membrane-bound TMPase activity was enhanced 1.7-fold by 5 mM Mg2+ ions and strongly inhibited by levamisole in uncompetitive manner with K1 of 53 μM, indicating the involvement of alkaline phosphatase. An apparent Km of alkaline phosphatase for TMP was calculated from the Hanes plot to be 0.6 mM. The soluble TMPase has an apparent Km of 0.7 mM; this enzyme is Mg2+ independent and insensitive to levamisole. As estimated by gel filtration on a Toyopearl HW-55 column, the soluble enzyme has a molecular mass of 17.8 kDa, TMPase activity being eluted simultaneously with peaks of flavinmononucleotide and p-nitrophenyl phosphatase activity. Thus, TMP appears to be a physiological substrate for a low-molecular weight acid phosphatase, also known as low-molecular-weight protein phosphotyrosine phosphatase.

Cellular prostatic acid phosphatase (cPAcP) serves as a useful biomarker of histone deacetylase (HDAC) inhibitors in prostate cancer cell growth suppression

Background

Prostate cancer (PCa) is the most commonly diagnosed solid tumor and the second leading cancer death in the United States, and also one of the major cancer-related deaths in Chinese. Androgen deprivation therapy (ADT) is the first line treatment for metastatic PCa. PCa ultimately relapses with subsequent ADT treatment failure and becomes castrate-resistant (CR). It is important to develop effective therapies with a surrogate marker towards CR PCa.

Method

Histone deacetylase (HDAC) inhibitors were examined to determine their effects in androgen receptor (AR)/cellular prostatic acid phosphatase (cPAcP)-positive PCa cells, including LNCaP C-33, C-81, C4-2 and C4-2B and MDA PCa2b androgen-sensitive and androgen-independent cells, and AR/cPAcP-negative PCa cells, including PC-3 and DU 145 cells. Cell growth was determined by cell number counting. Western blot analyses were carried out to determine AR, cPAcP and PSA protein levels.

Results

cPAcP protein level was increased by HDAC inhibitor treatment. Valproic acid, a HDAC inhibitor, suppressed the growth of AR/cPAcP-positive PCa cells by over 50% in steroid-reduced conditions, higher than on AR/cPAcP-negative PCa cells. Further, HDAC inhibitor pretreatments increased androgen responsiveness as demonstrated by PSA protein level quantitation.

Conclusion

Our results clearly demonstrate that HDAC inhibitors can induce cPAcP protein level, increase androgen responsiveness, and exhibit higher inhibitory activities on AR/cPAcP-positive PCa cells than on AR/cPAcP-negative PCa cells. Upon HDAC inhibitor pretreatment, PSA level was greatly elevated by androgens. This data indicates the potential clinical importance of cPAcP serving as a useful biomarker in the identification of PCa patient sub-population suitable for HDAC inhibitor treatment.

Can glycoprofiling be helpful in detecting prostate cancer?

Glycans are chains of carbohydrates attached to proteins (glycoproteins and proteoglycans) or lipids (glycolipids). Glycosylation is a posttranslational modification and glycans have a wide range of functions in a human body including involvement in oncological diseases. Change in a glycan structure cannot only indicate presence of a pathological process, but more importantly in some cases also its stage. Thus, a glycan analysis has a potential to be an effective and reliable tool in cancer diagnostics. Lectins are proteins responsible for natural biorecognition of glycans, even carbohydrate moieties still attached to proteins or whole cells can be recognized by lectins, what makes them an ideal candidate for designing label-free biosensors for glycan analysis. In this review we would like to summarize evidence that glycoprofiling of biomarkers by lectin-based biosensors can be really helpful in detecting prostate cancer.

Cellular prostatic acid phosphatase, a PTEN-functional homologue in prostate epithelia, functions as a prostate-specific tumor suppressor

The inactivation of tumor suppressor genes (TSGs) plays a vital role in the progression of human cancers. Nevertheless, those ubiquitous TSGs have been shown with limited roles in various stages of diverse carcinogenesis. Investigation on identifying unique TSG, especially for early stage of carcinogenesis, is imperative. As such, the search for organ-specific TSGs has emerged as a major strategy in cancer research. Prostate cancer (PCa) has the highest incidence in solid tumors in US males. Cellular prostatic acid phosphatase (cPAcP) is a prostate-specific differentiation antigen. Despite intensive studies over the past several decades on PAcP as a PCa biomarker, the role of cPAcP as a PCa-specific tumor suppressor has only recently been emerged and validated. The mechanism underlying the pivotal role of cPAcP as a prostate-specific TSG is, in part, due to its function as a protein tyrosine phosphatase (PTP) as well as a phosphoinositide phosphatase (PIP), an apparent functional homologue to phosphatase and tensin homolog (PTEN) in PCa cells. This review is focused on discussing the function of this authentic prostate-specific tumor suppressor and the mechanism behind the loss of cPAcP expression leading to prostate carcinogenesis. We review other phosphatases' roles as TSGs which regulate oncogenic PI3K signaling in PCa and discuss the functional similarity between cPAcP and PTEN in prostate carcinogenesis.