Glycosylation is a global target for androgen control in prostate cancer cells

The multifaceted role of intracellular glycosylation in cytoprotection and heart disease

The modification of nuclear, cytoplasmic, and mitochondrial proteins by O-linked β-N-actylglucosamine (O-GlcNAc) is an essential posttranslational modification that is common in metozoans. O-GlcNAc is cycled on and off proteins in response to environmental and physiological stimuli impacting protein function, which, in turn, tunes pathways that include transcription, translation, proteostasis, signal transduction, and metabolism. One class of stimulus that induces rapid and dynamic changes to O-GlcNAc is cellular injury, resulting from environmental stress (for instance, heat shock), hypoxia/reoxygenation injury, ischemia reperfusion injury (heart attack, stroke, trauma hemorrhage), and sepsis. Acute elevation of O-GlcNAc before or after injury reduces apoptosis and necrosis, suggesting that injury-induced changes in O-GlcNAcylation regulate cell fate decisions. However, prolonged elevation or reduction in O-GlcNAc leads to a maladaptive response and is associated with pathologies such as hypertrophy and heart failure. In this review, we discuss the impact of O-GlcNAc in both acute and prolonged models of injury with a focus on the heart and biological mechanisms that underpin cell survival.

Androgen drives melanoma invasiveness and metastatic spread by inducing tumorigenic fucosylation

Melanoma incidence and mortality rates are historically higher for men than women. Although emerging studies have highlighted tumorigenic roles for the male sex hormone androgen and its receptor (AR) in melanoma, cellular and molecular mechanisms underlying these sex-associated discrepancies are poorly defined. Here, we delineate a previously undisclosed mechanism by which androgen-activated AR transcriptionally upregulates fucosyltransferase 4 (FUT4) expression, which drives melanoma invasiveness by interfering with adherens junctions (AJs). Global phosphoproteomic and fucoproteomic profiling, coupled with in vitro and in vivo functional validation, further reveal that AR-induced FUT4 fucosylates L1 cell adhesion molecule (L1CAM), which is required for FUT4-increased metastatic capacity. Tumor microarray and gene expression analyses demonstrate that AR-FUT4-L1CAM-AJs signaling correlates with pathological staging in melanoma patients. By delineating key androgen-triggered signaling that enhances metastatic aggressiveness, our findings help explain sex-associated clinical outcome disparities and highlight AR/FUT4 and its effectors as potential prognostic biomarkers and therapeutic targets in melanoma.

Targeting aberrant sialylation and fucosylation in prostate cancer cells using potent metabolic inhibitors

Aberrant glycosylation is a hallmark of cancer and is not just a consequence, but also a driver of a malignant phenotype. In prostate cancer, changes in fucosylated and sialylated glycans are common and this has important implications for tumor progression, metastasis, and immune evasion. Glycans hold huge translational potential and new therapies targeting tumor-associated glycans are currently being tested in clinical trials for several tumor types. Inhibitors targeting fucosylation and sialylation have been developed and show promise for cancer treatment, but translational development is hampered by safety issues related to systemic adverse effects. Recently, potent metabolic inhibitors of sialylation and fucosylation were designed that reach higher effective concentrations within the cell, thereby rendering them useful tools to study sialylation and fucosylation as potential candidates for therapeutic testing. Here, we investigated the effects of global metabolic inhibitors of fucosylation and sialylation in the context of prostate cancer progression. We find that these inhibitors effectively shut down the synthesis of sialylated and fucosylated glycans to remodel the prostate cancer glycome with only minor apparent side effects on other glycan types. Our results demonstrate that treatment with inhibitors targeting fucosylation or sialylation decreases prostate cancer cell growth and downregulates the expression of genes and proteins important in the trajectory of disease progression. We anticipate our findings will lead to the broader use of metabolic inhibitors to explore the role of fucosylated and sialylated glycans in prostate tumor pathology and may pave the way for the development of new therapies for prostate cancer.

Radiotranscriptomics identified new mRNAs and miRNA markers for distinguishing prostate cancer from benign prostatic hyperplasia

The present study investigated ultrasound (US) phenotypes reflecting prostate cancer (PCa)-related genetic mutations. Herein, integration of radiotranscriptomic data, US and contrast-enhanced ultrasound (CEUS) radiomic images, and RNA sequencing was performed with the aim of significantly improving the accuracy of PCa prognosis. We performed radiotranscriptomic analysis of clinical, imaging, and two genomic (mRNA and microRNA expression) datasets from 48 and 22 men with PCa and benign prostatic hyperplasia (BPH), respectively. Twenty-three US texture features and four microvascular perfusion features were associated with various patterns of 52 differentially expressed genes related to PCa (p < 0.05); 17 overexpressed genes were associated with two key texture features. Twelve overexpressed genes were identified using microvascular perfusion features. Furthermore, mRNA and miRNA biomarkers could be used to distinguish between PCa and BPH. Compared with RNA sequencing, B-mode and CEUS features reflected genomic alterations associated with hormone receptor status, angiogenesis, and prognosis in patients with PCa. These findings indicate the potential of US to assess biomarker levels in patients with PCa.

The role of GCNT1 mediated O-glycosylation in aggressive prostate cancer

Prostate cancer is the most common cancer in men and a major cause of cancer related deaths worldwide. Nearly all affected men develop resistance to current therapies and there is an urgent need to develop new treatments for advanced disease. Aberrant glycosylation is a common feature of cancer cells implicated in all of the hallmarks of cancer. A major driver of aberrant glycosylation in cancer is the altered expression of glycosylation enzymes. Here, we show that GCNT1, an enzyme that plays an essential role in the formation of core 2 branched O-glycans and is crucial to the final definition of O-glycan structure, is upregulated in aggressive prostate cancer. Using in vitro and in vivo models, we show GCNT1 promotes the growth of prostate tumours and can modify the glycome of prostate cancer cells, including upregulation of core 2 O-glycans and modifying the O-glycosylation of secreted glycoproteins. Furthermore, using RNA sequencing, we find upregulation of GCNT1 in prostate cancer cells can alter oncogenic gene expression pathways important in tumour growth and metastasis. Our study highlights the important role of aberrant O-glycosylation in prostate cancer progression and provides novel insights regarding the mechanisms involved.

ST6GAL1-mediated aberrant sialylation promotes prostate cancer progression

Aberrant glycosylation is a universal feature of cancer cells, and cancer-associated glycans have been detected in virtually every cancer type. A common change in tumour cell glycosylation is an increase in α2,6 sialylation of N-glycans, a modification driven by the sialyltransferase ST6GAL1. ST6GAL1 is overexpressed in numerous cancer types, and sialylated glycans are fundamental for tumour growth, metastasis, immune evasion, and drug resistance, but the role of ST6GAL1 in prostate cancer is poorly understood. Here, we analyse matched cancer and normal tissue samples from 200 patients and verify that ST6GAL1 is upregulated in prostate cancer tissue. Using MALDI imaging mass spectrometry (MALDI-IMS), we identify larger branched α2,6 sialylated N-glycans that show specificity to prostate tumour tissue. We also monitored ST6GAL1 in plasma samples from >400 patients and reveal ST6GAL1 levels are significantly increased in the blood of men with prostate cancer. Using both in vitro and in vivo studies, we demonstrate that ST6GAL1 promotes prostate tumour growth and invasion. Our findings show ST6GAL1 introduces α2,6 sialylated N-glycans on prostate cancer cells and raise the possibility that prostate cancer cells can secrete active ST6GAL1 enzyme capable of remodelling glycans on the surface of other cells. Furthermore, we find α2,6 sialylated N-glycans expressed by prostate cancer cells can be targeted using the sialyltransferase inhibitor P-3FAX -Neu5Ac. Our study identifies an important role for ST6GAL1 and α2,6 sialylated N-glycans in prostate cancer progression and highlights the opportunity to inhibit abnormal sialylation for the development of new prostate cancer therapeutics. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

SPDEF enhances cancer stem cell-like properties and tumorigenesis through directly promoting GALNT7 transcription in luminal breast cancer

BACKGROUND

Luminal breast cancer (BC) is the predominant subtype of breast cancer with a sustained risk of late recurrence and death. Understanding the molecular mechanisms for the oncogenesis of luminal BC would improve the prognosis for this large subset of patients. SPDEF was reported to be dysregulated in breast cancers. However, the biological functions and underlying molecular mechanism of SPDEF in luminal BC remains largely unknown. The aim of the present study was to elucidate the potential roles of SPDEF underlying subtype-specific functions in BC, especially in luminal subtypes.

METHODS

The expressions and clinicopathological characteristics of SPDEF in luminal BC patients were evaluated bioinformatically. In vitro and in vivo assays were performed to investigate the oncogenic function and stemness maintenance of SPDEF in luminal BC. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were conducted to determine the transcription regulation of GALNT7 by SPDEF. GALNT7 levels in serum from luminal BC patients were further detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

SPDEF is markedly upregulated in luminal BC and positively associated with tumor progression and poor prognosis. Furthermore, we confirmed that SPDEF enhanced the proliferation, migration, invasion and stemness of luminal BC cells in vitro as well the tumorigenicity in vivo. Mechanistically, we demonstrated the stimulative effect of SPDEF on the progression and stemness of luminal BC, which is mediated by its directly transcriptional target GALNT7. Clinically, we verified that the GALNT7 can be used as a noninvasive diagnostic marker. Noteworthy, the combined detection of serum GALNT7 and traditional tumor markers can enhance diagnostic accuracy thus is of vital importance in the early diagnosis of luminal BC.

CONCLUSIONS

Our study reveals a novel mechanism by which SPDEF transcriptionally activates GALNT7 via directly binding to its promoter to promote cell proliferation, motility and stemness, and led to luminal BC tumorigenesis and poor prognosis.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Upregulation of GALNT7 in prostate cancer modifies O-glycosylation and promotes tumour growth

Prostate cancer is the most common cancer in men and it is estimated that over 350,000 men worldwide die of prostate cancer every year. There remains an unmet clinical need to improve how clinically significant prostate cancer is diagnosed and develop new treatments for advanced disease. Aberrant glycosylation is a hallmark of cancer implicated in tumour growth, metastasis, and immune evasion. One of the key drivers of aberrant glycosylation is the dysregulated expression of glycosylation enzymes within the cancer cell. Here, we demonstrate using multiple independent clinical cohorts that the glycosyltransferase enzyme GALNT7 is upregulated in prostate cancer tissue. We show GALNT7 can identify men with prostate cancer, using urine and blood samples, with improved diagnostic accuracy than serum PSA alone. We also show that GALNT7 levels remain high in progression to castrate-resistant disease, and using in vitro and in vivo models, reveal that GALNT7 promotes prostate tumour growth. Mechanistically, GALNT7 can modify O-glycosylation in prostate cancer cells and correlates with cell cycle and immune signalling pathways. Our study provides a new biomarker to aid the diagnosis of clinically significant disease and cements GALNT7-mediated O-glycosylation as an important driver of prostate cancer progression.

Molecular Aspects and Therapeutic Implications of Herbal Compounds Targeting Different Types of Cancer

Due to genetic changes in DNA (deoxyribonucleic acid) sequences, cancer continues to be the second most prevalent cause of death. The traditional target-directed approach, which is confronted with the importance of target function in healthy cells, is one of the most significant challenges in anticancer research. Another problem with cancer cells is that they experience various mutations, changes in gene duplication, and chromosomal abnormalities, all of which have a direct influence on the potency of anticancer drugs at different developmental stages. All of these factors combine to make cancer medication development difficult, with low clinical licensure success rates when compared to other therapy categories. The current review focuses on the pathophysiology and molecular aspects of common cancer types. Currently, the available chemotherapeutic drugs, also known as combination chemotherapy, are associated with numerous adverse effects, resulting in the search for herbal-based alternatives that attenuate resistance due to cancer therapy and exert chemo-protective actions. To provide new insights, this review updated the list of key compounds that may enhance the efficacy of cancer treatment.

Leucine zipper protein 2 serves as a prognostic biomarker for prostate cancer correlating with immune infiltration and epigenetic regulation

Background

We sought to determine whether leucine zipper protein 2 (LUZP2) could benefit men with prostate cancer (PCa) undergoing radical radiotherapy (RT) or prostatectomy (RP).

Methods

Analysis was done on differentiating expression, clinical prognosis, co-expressed genes, immune infiltration, and epigenetic changes. All of our analyses were done using the R software (version 3.6.3) and the appropriate packages.

Results

In terms of PCa, tumor samples expressed LUZP2 more than normal samples did. In the TCGA database and GSE116918, we found that LUZP2 was the only independent risk factor for PCa. The shared enriched pathways for patients undergoing RP or RT were cell-cell adhesion, regulation of filopodium assembly, and extracellular matrix containing collagen. With the exception of TNFRSF14, we discovered that LUZP2 was negatively correlated with 21 immune checkpoints in PCa patients receiving RT. We found a significant inverse relationship between LUZP2 expression and the tumor immune environment, which included B cells, CD4+ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score, and estimate score, in patients receiving RP or RT. Additionally, tumor purity was positively correlated with LUZP2. We found that the drug bortezomib may be susceptible to the LUZP2. DNA methylation was significantly associated with the mRNA expression of LUZP2 in PCa patients from the TCGA database, and LUZP2 methylation was positively correlated with immune cells. The proliferative activity of various PCa cells, which correlated to different stages of this disease, was also found to be significantly reduced by LUZP2 reduction, according to the results of our experimental work.

Conclusions

We proposed a relatively comprehensive understanding of the roles of LUZP2 on PCa from the fresh perspective of senescence.

Rat age-related benign prostate hyperplasia is concomitant with an increase in the secretion of low ramified α-glycosydic polysaccharides

This work analysed the expression of prostate polysaccharides in rats with age-related benign prostatic hyperplasia (BPH) for a better understanding of the possible relationship between prostate polysaccharides secretion and BPH onset. For this, prostatic glands from 1 month-old, 3 months-old, 6 months-old and 12 months-old Sprague-Dawley rats were processed in order to identify their overall polysaccharide content. Additionally, serum testosterone was also determined. One-month old rats showed significantly (P < 0.05) lower testosterone levels (0.77 ng/mL±0.12 ng/mL) compared with the other groups, which showed no significant difference among them. PAS staining showed positive polysaccharides markings in both the prostatic lumen and inside of luminal prostatic cells in all groups. Semiquantitative analysis of intraluminal PAS showed that one month-old rats had significantly (P < 0.005) lower PAS intensity when compared with all other groups (100.0 ± 0.5, arbitrary units vs. 107.3 ± 0.6, arbitrary units in 3 months-old ones), whereas 12 months-old ones showed significantly (P < 0.005) higher values when compared with all other groups (133.6 ± 3.5, arbitrary units in 12 months-old rats vs. 108.6 ± 1.4, arbitrary units in 6 months-old ones). The PAS + content practically disappeared when tissues were pre-incubated with either α-amylase or amyloglucosidase, regardless of a previous incubation with proteinase K. Incubation of prostate extracts from 12 months-old rats for 2 h with α-amylase yielded a significantly higher amount of free glucose (1.47 nmol/mg protein±0.23 nmol/mg protein vs. 0.32 nmol/mg protein±0.01 nmol/mg protein in untreated extracts). Similar results were obtained when extracts were pre-incubated with amyloglucosidase. Contrarily, pre-incubation with N-glycosidase induced a significantly (P < 0.05), much lower increase of free glucose. Pre-treatment with proteinase K did not significantly modify these results, which indicate that BPH is related to an increase in the secretion of low ramified ductal α-glycosydic polysaccharides that were not protected against lysis by any type of protein protective core. These changes seem to not be related with concomitant variations in serum testosterone levels.

Reformation of the chondroitin sulfate glycocalyx enables progression of AR-independent prostate cancer

Lineage plasticity of prostate cancer is associated with resistance to androgen receptor (AR) pathway inhibition (ARPI) and supported by a reactive tumor microenvironment. Here we show that changes in chondroitin sulfate (CS), a major glycosaminoglycan component of the tumor cell glycocalyx and extracellular matrix, is AR-regulated and promotes the adaptive progression of castration-resistant prostate cancer (CRPC) after ARPI. AR directly represses transcription of the 4-O-sulfotransferase gene CHST11 under basal androgen conditions, maintaining steady-state CS in prostate adenocarcinomas. When AR signaling is inhibited by ARPI or lost during progression to non-AR-driven CRPC as a consequence of lineage plasticity, CHST11 expression is unleashed, leading to elevated 4-O-sulfated chondroitin levels. Inhibition of the tumor cell CS glycocalyx delays CRPC progression, and impairs growth and motility of prostate cancer after ARPI. Thus, a reactive CS glycocalyx supports adaptive survival and treatment resistance after ARPI, representing a therapeutic opportunity in patients with advanced prostate cancer.

Chondroitin sulfate (CS) is one of the most abundant glycosaminoglycans in prostate cancers. Here the authors show that inhibition of the androgen receptor pathway leads to the upregulation of CS, which promotes prostate cancer growth and metastasis.

Pro-Survival Factor EDEM3 Confers Therapy Resistance in Prostate Cancer

Prostate cancer is the most common cancer in men, and it is primarily driven by androgen steroid hormones. The glycosylation enzyme EDEM3 is controlled by androgen signalling and is important for prostate cancer viability. EDEM3 is a mannosidase that trims mannose from mis-folded glycoproteins, tagging them for degradation through endoplasmic reticulum-associated degradation. Here, we find that EDEM3 is upregulated in prostate cancer, and this is linked to poorer disease-free survival. Depletion of EDEM3 from prostate cancer cells induces an ER stress transcriptomic signature, and EDEM3 overexpression is cyto-protective against ER stressors. EDEM3 expression also positively correlates with genes involved in the unfolded protein response in prostate cancer patients, and its expression can be induced through exposure to radiation. Importantly, the overexpression of EDEM3 promotes radio-resistance in prostate cancer cells and radio-resistance can be reduced through depletion of EDEM3. Our data thus implicate increased levels of EDEM3 with a role in prostate cancer pathology and reveal a new therapeutic opportunity to sensitise prostate tumours to radiotherapy.

N-glycosylation of GDF15 abolishes its inhibitory effect on EGFR in AR inhibitor-resistant prostate cancer cells

Castration-resistance of prostate cancer is one of the most challenging clinical problems. In the present study, we have performed proteomics and glycomics using LNCaP model. Growth differentiation factor-15 (GDF15) level is increased in androgen receptor (AR) inhibitor-resistant cells and the inhibitory effect of GDF15 on epithelial growth factor receptor (EGFR) pathway is relieved by GDF15 N70 glycosylation. Interference of GDF15 (siRNA or N70Q dominant negative) or EGFR pathway (inhibitor or siRNA for EGFR, SRC or ERK) decreases the resistant-cell survival in culture and tumor growth in mice. Our study reveals a novel regulatory mechanism of prostate cancer AR inhibitor resistance, raises the possibility of AR/SRC dual-targeting of castration-resistance of prostate cancer, and lays foundation for the future development of selective inhibitors of GDF15 glycosylation.

Functional analysis of GCNT3 for cell migration and EMT of castration-resistant prostate cancer cells

Castration-resistant prostate cancer (CRPC) is a malignant tumor that is resistant to androgen deprivation therapy. Treatments for CRPC are limited, and no diagnostic markers are currently available. O-glycans are known to play an important role in cell proliferation, migration, invasion, and metastasis of cancer cells. However, the differences in the O-glycan expression profiles for normal prostate cancer (PCa) cells compared to CRPC cells have not yet been investigated. In this study, the saccharide primer method was employed to analyze the O-glycans expressed in CRPC cells. Expression levels of core 4-type O-glycans were significantly increased in CRPC cells. Furthermore, the expression level of N-Acetylglucosaminyltransferase 3 (GCNT3), a core 4-type O-glycan synthase gene, was increased in CRPC cells. The expression of core 4-type O-glycans and GCNT3 was presumed to be regulated by androgen deprivation. GCNT3 knockdown induced cell migration and epithelial-mesenchymal transition (EMT). These observations elucidate the mechanism of acquisition of castration resistance in PCa and offer new possibilities for the development of diagnostic markers and therapeutic targets in the treatment of PCa.

VPRBP Functions Downstream of the Androgen Receptor and OGT to Restrict p53 Activation in Prostate Cancer

Androgen receptor (AR) is a major driver of prostate cancer initiation and progression. O-GlcNAc transferase (OGT), the enzyme that catalyzes the covalent addition of UDP-N-acetylglucosamine (UDP-GlcNAc) to serine and threonine residues of proteins, is often highly expressed in prostate cancer with its expression correlated with high Gleason score. In this study, we have identified an AR and OGT coregulated factor, Vpr (HIV-1) binding protein (VPRBP) also known as DDB1 and CUL4 Associated Factor 1 (DCAF1). We show that VPRBP is regulated by the AR at the transcript level, and stabilized by OGT at the protein level. VPRBP knockdown in prostate cancer cells led to a significant decrease in cell proliferation, p53 stabilization, nucleolar fragmentation, and increased p53 recruitment to the chromatin. In human prostate tumor samples, VPRBP protein overexpression correlated with AR amplification, OGT overexpression, a shorter time to postoperative biochemical progression and poor clinical outcome. In clinical transcriptomic data, VPRBP expression was positively correlated with the AR and also with AR activity gene signatures.

IMPLICATIONS

In conclusion, we have shown that VPRBP/DCAF1 promotes prostate cancer cell proliferation by restraining p53 activation under the influence of the AR and OGT.

Prognostic and Therapeutic Role of CD15 and CD15s in Cancer

Simple Summary

CD15 (Lewis X) is a typical myeloid antigen presented in myeloid and monocytic lineages of cells. This molecule interacts with E-, L- and P-selectins, which allows for adhesion with endothelial cells. CD15 is found on various cancer cells, including renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma cells. Its high expression can serve as a prognostic marker for patients and is a potentially valuable target for immunotherapy against cancer. Blockage of the antigen’s function results in reduced metastatic potential and it may be an immunotherapeutic target. CD15s is a sialyl derivative of CD15; however, unlike the high expression of CD15, which is a prognostic factor in Hodgkin lymphoma, CD15s relates to poor prognosis for patients. CD15 is considered a marker of cancer stem cells. This review presents a comprehensive description of the prognostic role of CD15 and CD15s and their use in anticancer therapy.

Abstract

CD15 (Lewis X/Lex) is a fucosyl (3-fucosly-N-acetyl-lactosamine) moiety found on membrane proteins of various cancer cells. These cancers include renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma. The biological role of CD15 is interaction with E-, L- and P-selectins (adhesion molecules), allowing for adhesion with endothelial cells. In this way, cancer cells start to interact with the endothelia of blood vessels and consequently move out from the blood flow to the surrounding tissues. Blockage of the antigen’s function results in reduced metastatic potential. Moreover, the molecule may be a therapeutic target against cancer in monoclonal antibody-based therapies. CD15 may serve as a prognostic marker for patients and there are high hopes for its use in the immunotherapeutic treatment of tumours. CD15s is a sialyl derivative of CD15 that possesses its own unique characteristics. Its soluble form may act as a competitive inhibitor of the interaction of cancer cells with epithelial cells and thus disallow migration through the vessels. However, the prognostic relevance of CD15 and CD15s expression is very complex. This review presents a comprehensive description of the role of CD15 and CD15s in cancer development and metastasis and overviews its significance for clinical applications.

Discovery proteomics defines androgen-regulated glycoprotein networks in prostate cancer cells, as well as putative biomarkers of prostatic diseases

Supraphysiologic androgen (SPA) inhibits cell proliferation in prostate cancer (PCa) cells by transcriptional repression of DNA replication and cell-cycle genes. In this study, quantitative glycoprotein profiling identified androgen-regulated glycoprotein networks associated with SPA-mediated inhibition of PCa cell proliferation, and androgen-regulated glycoproteins in clinical prostate tissues. SPA-regulated glycoprotein networks were enriched for translation factors and ribosomal proteins, proteins that are known to be O-GlcNAcylated in response to various cellular stresses. Thus, androgen-regulated glycoproteins are likely to be targeted for O-GlcNAcylation. Comparative analysis of glycosylated proteins in PCa cells and clinical prostate tissue identified androgen-regulated glycoproteins that are differentially expressed prostate tissues at various stages of cancer. Notably, the enzyme ectonucleoside triphosphate diphosphohydrolase 5 was found to be an androgen-regulated glycoprotein in PCa cells, with higher expression in cancerous versus non-cancerous prostate tissue. Our glycoproteomics study provides an experimental framework for characterizing androgen-regulated proteins and glycoprotein networks, toward better understanding how this subproteome leads to physiologic and supraphysiologic proliferation responses in PCa cells, and their potential use as druggable biomarkers of dysregulated AR-dependent signaling in PCa cells.

ST8SIA1 inhibits the proliferation, migration and invasion of bladder cancer cells by blocking the JAK/STAT signaling pathway

Bladder cancer (BLCA) is the most common malignant tumor of the urinary system, with distant metastasis of the tumor being the main cause of death. The identification of an effective biomarker may provide a novel direction for BLCA diagnosis and treatment. The aim of the present study was to screen the BLCA-related genes involved in sialyl transferase (ST) dysregulation and to investigate the functional mechanisms of α-2,8-ST1 (ST8SIA1) in BLCA cells. Data from The Cancer Genome Atlas and Gene Expression Profiling Interactive Analysis databases suggested that the mRNA expression levels of ST8SIA1 were decreased in BLCA tissues compared with normal tissues, which was also demonstrated using immunohistochemistry and western blot analysis. The expression levels of ST8SIA1 were negatively associated with the pathological grade and invasiveness of BLCA. Western blot analysis revealed that the expression levels of ST8SIA1 were lower in BLCA cell lines than in a normal urothelial cell line. CCK-8, flow cytometry, wound healing, colony formation and Transwell assays indicated that ST8SIA1 overexpression attenuated the proliferation, migration and invasion of T24 and 5637 BLCA cells. Further experiments revealed that ST8SIA1 could inhibit the phosphorylation of Janus kinase (JAK)2 and STAT3, as well as decrease the expression levels of JAK/STAT pathway-targeting signal molecules, including MMP2, proliferating cell nuclear antigen, cyclin D1 and Bcl2 in two BLCA cell lines. In conclusion, to the best of our knowledge, the present study was the first to indicate that the antitumor effect of ST8SIA1 in BLCA cells was mediated by the JAK/STAT signaling pathway, and the results provided a novel target for the diagnosis and treatment of BLCA.

Glycosylation: Rising Potential for Prostate Cancer Evaluation

Simple Summary

Aberrant protein glycosylation is a well-known hallmark of cancer and is associated with differential expression of enzymes such as glycosyltransferases and glycosidases. The altered expression of the enzymes triggers cancer cells to produce glycoproteins with specific cancer-related aberrations in glycan structures. Increasing number of data indicate that glycosylation patterns of PSA and other prostate-originated proteins exert a potential to distinguish between benign prostate disease and cancer as well as among different stages of prostate cancer development and aggressiveness. This review summarizes the alterations in glycan sialylation, fucosylation, truncated O-glycans, and LacdiNAc groups outlining their potential applications in non-invasive diagnostic procedures of prostate diseases. Further research is desired to develop more general algorithms exploiting glycobiology data for the improvement of prostate diseases evaluation.

Abstract

Prostate cancer is the second most commonly diagnosed cancer among men. Alterations in protein glycosylation are confirmed to be a reliable hallmark of cancer. Prostate-specific antigen is the biomarker that is used most frequently for prostate cancer detection, although its lack of sensitivity and specificity results in many unnecessary biopsies. A wide range of glycosylation alterations in prostate cancer cells, including increased sialylation and fucosylation, can modify protein function and play a crucial role in many important biological processes in cancer, including cell signalling, adhesion, migration, and cellular metabolism. In this review, we summarize studies evaluating the prostate cancer associated glycosylation related alterations in sialylation, mainly α2,3-sialylation, core fucosylation, branched N-glycans, LacdiNAc group and presence of truncated O-glycans (sTn, sT antigen). Finally, we discuss the great potential to make use of glycans as diagnostic and prognostic biomarkers for prostate cancer.

Detection of N,N-diacetyllactosamine (LacdiNAc) containing free prostate-specific antigen for early stage prostate cancer diagnostics and for identification of castration-resistant prostate cancer patients

Prostate cancer (PCa) is one of the most common cancer types among men and also acommon cause of death globally. With an increasing incidence, there is aneed for low-cost, reliable biomarkers present in samples, which could be provided non-invasively (without a need to perform prostate biopsy). Glycosylation changes of free-PSA (fPSA) are considered cancer-specific, while the level of different PSA forms can increase under other than cancerous conditions. In the present study, we investigated the role ofN,N-diacetyllactosamine (LacdiNAc) epitope of fPSA (i.e. glycoprofile of fPSA or gPSA) in combination with total-PSA (tPSA), prostate volume, and tPSA density (tPSA level divided by prostate volume i.e. PSAd) as biomarkers for monitoring of PCa development and progression in 105 men. Furthermore, we applied an genetic (evolutionary) algorithm to identify any suspicious individuals in abenign cohort having benign prostatic hyperplasia (BPH). We identified 3 suspicious men originally diagnosed with BPH using gPSA analysis. In thefollow-up we found out that two men should not be considered as BPH patients since multiparametric magnetic resonance imaging (mpMRI) identified one man with clinically significant PCa via Prostate Imaging - Reporting and Data System (PI RADS v2 = 4) and the second man was with High-gradeprostatic intraepithelial neoplasia (HG PIN), commonly described as apre-cancerous stage. Moreover, in the study we described for the first time that changed LacdiNAc on PSA can be applied to identify prostatitis patients and most importantly this is the first study suggesting that changed glycosylation on PSA can be applied to identify castration-resistant prostate cancer (CRPCa) patients.

Automated Quantification of Hydroxyl Reactivities: Prediction of Glycosylation Reactions

The stereoselectivity and yield in glycosylation reactions are paramount but unpredictable. We have developed a database of acceptor nucleophilic constants (Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure high reproducibility and accuracy. A diverse range of glycosylation donors and acceptors with well-defined reactivity and promoters were organized and processed by the designed software program "GlycoComputer" for prediction of glycosylation reactions without involving sophisticated computational processing. The importance of Aka was further verified by random forest algorithm, and the applicability was tested by the synthesis of a Lewis A skeleton to show that the stereoselectivity and yield can be accurately estimated.

Narrative review of urinary glycan biomarkers in prostate cancer

Prostate cancer (PC) is the second most common cancer in men worldwide. The application of the prostate-specific antigen (PSA) test has improved the diagnosis and treatment of PC. However, the PSA test has become associated with overdiagnosis and overtreatment. Therefore, there is an unmet need for novel diagnostic, prognostic, and predictive biomarkers of PC. Urinary glycoproteins and exosomes are a potential source of PC glycan biomarkers. Urinary glycan profiling can provide noninvasive monitoring of tumor heterogeneity and aggressiveness throughout a treatment course. However, urinary glycan profiling is not popular due to technical disadvantages, such as complicated structural analysis that requires specialized expertise. The technological development of glycan analysis is a rapidly advancing field. A lectin-based microarray can detect aberrant glycoproteins in urine, including PSA glycoforms and exosomes. Glycan enrichment beads can enrich the concentration of N-linked glycans specifically. Capillary electrophoresis, liquid chromatography-tandem mass spectrometry, and matrix-assisted laser desorption/ionization-time of flight mass spectrometry can detect glycans directory. Many studies suggest potential of urinary glycoproteins, exosomes, and glycosyltransferases as a biomarker of PC. Although further technological challenges remain, urinary glycan analysis is one of the promising approaches for cancer biomarker discovery.

Glutaminolysis is a metabolic route essential for survival and growth of prostate cancer cells and a target of 5α-dihydrotestosterone regulation

PURPOSE

Resistance to androgen-deprivation therapies and progression to so-called castrate-resistant prostate cancer (CRPC) remain challenges in prostate cancer (PCa) management and treatment. Among other alterations, CRPC has been associated with metabolic reprogramming driven by androgens. Here, we investigated the role of androgens in regulating glutaminolysis in PCa cells and determined the relevance of this metabolic route in controlling the survival and growth of androgen-sensitive (LNCaP) and CRPC (DU145 and PC3) cells.

METHODS

PCa cells (LNCaP, DU145 and PC3) and 3-month old rats were treated with 5α-dihydrotestosterone (DHT). Alternatively, LNCaP cells were exposed to the glutaminase inhibitor BPTES, alone or in combination with the anti-androgen bicalutamide. Biochemical, Western blot and extracellular flux assays were used to evaluate the viability, proliferation, migration and metabolism of PCa cells in response to DHT treatment or glutaminase inhibition.

RESULTS

We found that DHT up-regulated the expression of the glutamine transporter ASCT2 and glutaminase, both in vitro in LNCaP cells and in vivo in rat prostate cells. BPTES diminished the viability and migration of PCa cells, while increasing caspase-3 activity. CRPC cells were found to be more dependent on glutamine and more sensitive to glutaminase inhibition. BPTES and bicalutamide co-treatment had an additive effect on suppressing LNCaP cell viability. Finally, we found that inhibition of glutaminolysis differentially affected glycolysis and lipid metabolism in both androgen-sensitive and CRPC cells.

CONCLUSION

Our data reveal glutaminolysis as a central metabolic route controlling PCa cell fate and highlight the relevance of targeting glutaminase for CRPC treatment.

The Complexity and Dynamics of the Tissue Glycoproteome Associated With Prostate Cancer Progression

The complexity and dynamics of the immensely heterogeneous glycoproteome of the prostate cancer (PCa) tumor microenvironment remain incompletely mapped, a knowledge gap that impedes our molecular-level understanding of the disease. To this end, we have used sensitive glycomics and glycoproteomics to map the protein-, cell-, and tumor grade-specific N- and O-glycosylation in surgically removed PCa tissues spanning five histological grades (n = 10/grade) and tissues from patients with benign prostatic hyperplasia (n = 5). Quantitative glycomics revealed PCa grade-specific alterations of the oligomannosidic-, paucimannosidic-, and branched sialylated complex-type N-glycans, and dynamic remodeling of the sialylated core 1- and core 2-type O-glycome. Deep quantitative glycoproteomics identified ∼7400 unique N-glycopeptides from 500 N-glycoproteins and ∼500 unique O-glycopeptides from nearly 200 O-glycoproteins. With reference to a recent Tissue and Blood Atlas, our data indicate that paucimannosidic glycans of the PCa tissues arise mainly from immune cell-derived glycoproteins. Furthermore, the grade-specific PCa glycosylation arises primarily from dynamics in the cellular makeup of the PCa tumor microenvironment across grades involving increased oligomannosylation of prostate-derived glycoproteins and decreased bisecting GlcNAcylation of N-glycans carried by the extracellular matrix proteins. Furthermore, elevated expression of several oligosaccharyltransferase subunits and enhanced N-glycoprotein site occupancy were observed associated with PCa progression. Finally, correlations between the protein-specific glycosylation and PCa progression were observed including increased site-specific core 2-type O-glycosylation of collagen VI. In conclusion, integrated glycomics and glycoproteomics have enabled new insight into the complexity and dynamics of the tissue glycoproteome associated with PCa progression generating an important resource to explore the underpinning disease mechanisms.

The Role of Glycosylation in Infectious Diseases

Glycosylation plays an important role in infectious diseases. Many important interactions between pathogens and hosts involve their carbohydrate structures (glycans). Glycan interactions can mediate adhesion, recognition, invasion, and immune evasion of pathogens. To date, changes in many protein N/O-linked glycosylation have been identified as biomarkers for the development of infectious diseases and cancers. In this review, we will discuss the principal findings and the roles of glycosylation of both pathogens and host cells in the context of human important infectious diseases. Understanding the role and mechanism of glycan-lectin interaction between pathogens and hosts may create a new paradigm for discovering novel glycan-based therapies that can lead to eradication or functional cure of pathogens infection.

Insights into Bioinformatic Applications for Glycosylation: Instigating an Awakening towards Applying Glycoinformatic Resources for Cancer Diagnosis and Therapy

Glycosylation plays a crucial role in various diseases and their etiology. This has led to a clear understanding on the functions of carbohydrates in cell communication, which eventually will result in novel therapeutic approaches for treatment of various disease. Glycomics has now become one among the top ten technologies that will change the future. The direct implication of glycosylation as a hallmark of cancer and for cancer therapy is well established. As in proteomics, where bioinformatics tools have led to revolutionary achievements, bioinformatics resources for glycosylation have improved its practical implication. Bioinformatics tools, algorithms and databases are a mandatory requirement to manage and successfully analyze large amount of glycobiological data generated from glycosylation studies. This review consolidates all the available tools and their applications in glycosylation research. The achievements made through the use of bioinformatics into glycosylation studies are also presented. The importance of glycosylation in cancer diagnosis and therapy is discussed and the gap in the application of widely available glyco-informatic tools for cancer research is highlighted. This review is expected to bring an awakening amongst glyco-informaticians as well as cancer biologists to bridge this gap, to exploit the available glyco-informatic tools for cancer.

Prospects for Using Expression Patterns of Paramyxovirus Receptors as Biomarkers for Oncolytic Virotherapy

Simple Summary

Some non-pathogenic viruses that do not cause serious illness in humans can efficiently target and kill cancer cells and may be considered candidates for cancer treatment with virotherapy. However, many cancer cells are protected from viruses. An important goal of personalized cancer treatment is to identify viruses that can kill a certain type of cancer cells. To this end, researchers investigate expression patterns of cell entry receptors, which viruses use to bind to and enter host cells. We summarized and analyzed the receptor expression patterns of two paramyxoviruses: The non-pathogenic measles and the Sendai viruses. The receptors for these viruses are different and can be proteins or lipids with attached carbohydrates. This review discusses the prospects for using these paramyxovirus receptors as biomarkers for successful personalized virotherapy for certain types of cancer.

Abstract

The effectiveness of oncolytic virotherapy in cancer treatment depends on several factors, including successful virus delivery to the tumor, ability of the virus to enter the target malignant cell, virus replication, and the release of progeny virions from infected cells. The multi-stage process is influenced by the efficiency with which the virus enters host cells via specific receptors. This review describes natural and artificial receptors for two oncolytic paramyxoviruses, nonpathogenic measles, and Sendai viruses. Cell entry receptors are proteins for measles virus (MV) and sialylated glycans (sialylated glycoproteins or glycolipids/gangliosides) for Sendai virus (SeV). Accumulated published data reviewed here show different levels of expression of cell surface receptors for both viruses in different malignancies. Patients whose tumor cells have low or no expression of receptors for a specific oncolytic virus cannot be successfully treated with the virus. Recent published studies have revealed that an expression signature for immune genes is another important factor that determines the vulnerability of tumor cells to viral infection. In the future, a combination of expression signatures of immune and receptor genes could be used to find a set of oncolytic viruses that are more effective for specific malignancies.

Statistical Analysis of Glycosylation Reactions

Chemical synthesis is one of the practical approaches to access carbohydrate-based natural products and their derivatives with high quality and in a large quantity. However, stereoselectivity during the glycosylation reaction is the main challenge because the reaction can generate both α- and β-glycosides. The main focus of the present article is the concept of recent mechanistic studies that have applied statistical analysis and quantitation for defining stereoselective changes during the reaction process. Based on experimental evidence, a detailed discussion associated with the mechanism and degree of influence affecting the stereoselective outcome of glycosylation is included.

Super-Enhancer Associated Five-Gene Risk Score Model Predicts Overall Survival in Multiple Myeloma Patients

Multiple myeloma (MM) is a malignant plasma cell tumor with high heterogeneity, characterized by anemia, hypercalcemia, renal failure, and lytic bone lesions. Although various powerful prognostic factors and models have been exploited, the development of more accurate prognosis and treatment for MM patients is still facing many challenges. Given the essential roles of super-enhancer (SE) associated genes in the tumorigenesis of MM, we tried to initially screen and identify the significant prognostic factors from SE associated genes in MM by the least absolute shrinkage and selection operator (Lasso) penalized Cox regression, univariate and multivariate Cox regression analysis using GSE24080 and GSE9782 datasets. Risk score model of five genes including CSGALNACT1, FAM53B, TAPBPL, REPIN1, and DDX11, was further constructed and the Kaplan-Meier (K-M) curves showed that the low-risk group seems to have better clinical outcome of survival compared to the high-risk group. Time-dependent receiver operating characteristic (ROC) curves presented the favorable performance of the model. An interactive nomogram consisting of the five-gene risk group and eleven clinical traits was established and identified by calibration curves. Therefore, the risk score model of SE associated five genes developed here could be used to predict the prognosis of MM patients, which may assist the clinical treatment of MM patients in the future.

Characterisation of the main PSA glycoforms in aggressive prostate cancer

Serum levels of prostate specific antigen (PSA) are commonly used for prostate cancer (PCa) detection. However, their lack of specificity to distinguish benign prostate pathologies from PCa, or indolent from aggressive PCa have prompted the study of new non-invasive PCa biomarkers. Aberrant glycosylation is involved in neoplastic progression and specific changes in PSA glycosylation pattern, as the reduction in the percentage of α2,6-sialic acid (SA) are associated with PCa aggressiveness. In this study, we have characterised the main sialylated PSA glycoforms from blood serum of aggressive PCa patients and have compared with those of standard PSA from healthy individuals’ seminal plasma. PSA was immunoprecipitated and α2,6-SA were separated from α2,3-SA glycoforms using SNA affinity chromatography. PSA N-glycans were released, labelled and analysed by hydrophilic interaction liquid chromatography combined with exoglycosidase digestions. The results showed that blood serum PSA sialylated glycoforms containing GalNAc residues were largely increased in aggressive PCa patients, whereas the disialylated core fucosylated biantennary structures with α2,6-SA, which are the major PSA glycoforms in standard PSA from healthy individuals, were markedly reduced in aggressive PCa. The identification of these main PSA glycoforms altered in aggressive PCa opens the way to design specific strategies to target them, which will be useful to improve PCa risk stratification.

EIF4G1 and RAN as Possible Drivers for Malignant Pleural Mesothelioma

For malignant pleural mesothelioma (MPM) novel therapeutic strategies are urgently needed. In a previous study, we identified 51 putative cancer genes over-expressed in MPM tissues and cell lines. Here, we deepened the study on nine of them (ASS1, EIF4G1, GALNT7, GLUT1, IGF2BP3 (IMP3), ITGA4, RAN, SOD1, and THBS2) to ascertain whether they are truly mesothelial cancer driver genes (CDGs) or genes overexpressed in an adaptive response to the tumoral progression (“passenger genes”). Through a fast siRNA-based screening, we evaluated the consequences of gene depletion on migration, proliferation, colony formation capabilities, and caspase activities of four MPM (Mero-14, Mero-25, IST-Mes2, and NCI-H28) and one SV40-immortalized mesothelial cell line (MeT-5A) as a non-malignant model. The depletion of EIF4G1 and RAN significantly reduced cell proliferation and colony formation and increased caspase activity. In particular, the findings for RAN resemble those observed for other types of cancer. Thus, we evaluated the in vitro effects of importazole (IPZ), a small molecule inhibitor of the interaction between RAN and importin-β. We showed that IPZ could have effects similar to those observed following RAN gene silencing. We also found that primary cell lines from one out of three MPM patients were sensitive to IPZ. As EIF4G1 and RAN deserve further investigation with additional in vitro and in vivo studies, they emerged as promising CDGs, suggesting that their upregulation could play a role in mesothelial tumorigenesis and aggressiveness. Furthermore, present data propose the molecular pathways dependent on RAN as a putative pharmacological target for MPM patients in the view of a future personalized medicine.

The expression and functional analysis of the sialyl-T antigen in prostate cancer

Aberrant glycosylation is a featured characteristic of cancer and plays a role in cancer pathology; thus an understanding of the compositions and functions of glycans is critical for discovering diagnostic biomarkers and therapeutic targets for cancer. In this study, we used MALDI-TOF-MS analysis to determine the O-glycan profiles of prostate cancer cells metastasized to bone (PC-3), brain (DU145), lymph node (LNCaP), and vertebra (VCaP) in comparison to immortalized RWPE-1 cells derived from normal prostatic tissue. Prostate cancer (CaP) cells exhibited an elevation of simple/short O-glycans, with a reduction of complex O-glycans, increased O-glycan sialylation and decreased fucosylation. Core 1 sialylation was increased dramatically in all CaP cells, and especially in PC-3 cells. The expression of Neu5Acα2-3Galβ1-3GalNAc- (sialyl-3T antigen) which is the product of α2,3-sialyltransferase-I (ST3Gal-I) was substantially increased. We therefore focused on exploring the possible function of ST3Gal-I in PC-3 cells. ST3Gal-I silencing studies showed that ST3Gal-I was associated with PC-3 cell proliferation, migration and apoptosis. Further in vivo studies demonstrated that down regulation of ST3Gal-I reduced the tumor size in xenograft mouse model, indicating that sialyl-3T can serve as a biomarker for metastatic prostate cancer prognosis, and that ST3Gal-I could be a target for therapeutic intervention in cancer treatment.

Bioinformatic identification of differentially expressed genes associated with prognosis of locally advanced lymph node-positive prostate cancer

Prostate cancer (PCa) is one of the primary causes of cancer-related mortality in men worldwide. Patients with locally advanced PCa with metastases in regional lymph nodes are usually marked as a high-risk group. One of the chief concerns for this group is to make an informed decision about the necessity of conducting adjuvant androgen deprivation therapy after radical surgical treatment. During the oncogenic transformation and progression of the disease, the expression of many genes is altered. Some of these genes can serve as markers for diagnosis, predicting the prognosis or effectiveness of drug therapy, as well as possible therapeutic targets. We undertook bioinformatic analysis of the RNA-seq data deposited in The Cancer Genome Atlas consortium database to identify possible prognostic markers. We compared the groups with favorable and unfavorable prognosis for the cohort of patients with PCa showing lymph node metastasis (pT2N1M0, pT3N1M0, and pT4N1M0) and for the most common molecular type carrying the fusion transcript TMPRSS2-ERG. For the entire cohort, we revealed at least six potential markers (IDO1, UGT2B15, IFNG, MUC6, CXCL11, and GBP1). Most of these genes are involved in the positive regulation of immune response. For the TMPRSS2-ERG subtype, we also identified six genes, the expression of which may be associated with prognosis: TOB1, GALNT7, INAFM1, APELA, RAC3, and NNMT. The identified genes, after additional studies and validation in the extended cohort, could serve as a prognostic marker of locally advanced lymph node-positive PCa.

Targeting Aberrant Sialylation to Treat Cancer

Cell surface carbohydrates (known as glycans) are often aberrantly expressed or found at atypical levels in cancer. Glycans can impact all steps in tumour progression, from malignant transformation to metastasis, and have roles in all the cancer hallmarks. An increased understanding of glycans in the metastatic cascade offers exciting new therapeutic opportunities. Glycan-based targeting strategies are currently being tested in clinical trials and are a rich and untapped frontier for development. As we learn more about cancer glycobiology, new targets will continue to emerge for drug design. One key change in tumour glycosylation is the upregulation of cancer-associated sialylated glycans. Abnormal sialylation is integral to tumour growth, metastasis and immune evasion; therefore, targeting sialic acid moieties in cancer could be of high therapeutic value. Here, we summarise the changes to sialic acid biology in cancer and discuss recent advances and technologies bringing sialic-acid targeting treatments to the forefront of cancer therapeutics.

Single Cell Gene Co-Expression Network Reveals FECH/CROT Signature as a Prognostic Marker

Aberrant activation of signaling pathways is frequently observed and reported to be associated with the progression and poor prognosis of prostate cancer (PCa). We aimed to identify key biological processes regulated by androgen receptor (AR) using gene co-expression network from single cell resolution. The bimodal index was used to evaluate whether two subpopulations exist among the single cells. Gene expression among single cells revealed averaging pitfalls and bimodality pattern. Weighted gene co-expression network analysis (WGCNA) was used to identify modules of highly correlated genes. Twenty-nine gene modules were identified and AR-regulated modules were screened by significantly overlapping reported androgen induced differentially expressed genes. The biological function "generation of precursor metabolites and energy" was significantly enriched by AR-regulated modules with bimodality, presenting differential androgen response among subpopulations. Integrating with public ChIP-seq data, two genes FECH, and CROT has AR binding sites. Public in vitro studies also show that androgen regulates FECH and CROT. After receiving androgen deprivation therapy, patients lowly express FECH and CROT. Further survival analysis indicates that FECH/CROT signature can predict PCa recurrence. We reveal the heterogeneous function of "generation of precursor metabolites and energy" upon androgen stimulation from the perspective of single cells. Inhibitors targeting this biological process will facilitate to prevent prostate cancer progression.

ST6GAL1: A key player in cancer

Aberrant glycosylation is a universal feature of cancer cells and there is now overwhelming evidence that glycans can modulate pathways intrinsic to tumour cell biology. Glycans are important in all of the cancer hallmarks and there is a renewed interest in the glycomic profiling of tumours to improve early diagnosis, determine patient prognosis and identify targets for therapeutic intervention. One of the most widely occurring cancer associated changes in glycosylation is abnormal sialylation which is often accompanied by changes in sialyltransferase activity. Several sialyltransferases are implicated in cancer, but in recent years ST6 β-galactoside α-2,6-sialyltransferase 1 (ST6GAL1) has become increasingly dominant in the literature. ST6GAL1 catalyses the addition of α2,6-linked sialic acids to terminal N-glycans and can modify glycoproteins and/or glycolipids. ST6GAL1 is upregulated in numerous types of cancer (including pancreatic, prostate, breast and ovarian cancer) and can promote growth, survival and metastasis. The present review discusses ST6GAL in relation to the hallmarks of cancer, and highlights its key role in multiple mechanisms intrinsic to tumour cell biology.

Glycans as Biomarkers in Prostate Cancer

Prostate cancer is the most commonly diagnosed malignancy in men, claiming over350,000 lives worldwide annually. Current diagnosis relies on prostate-specific antigen (PSA)testing, but this misses some aggressive tumours, and leads to the overtreatment of non-harmfuldisease. Hence, there is an urgent unmet clinical need to identify new diagnostic and prognosticbiomarkers. As prostate cancer is a heterogeneous and multifocal disease, it is likely that multiplebiomarkers will be needed to guide clinical decisions. Fluid-based biomarkers would be ideal, andattention is now turning to minimally invasive liquid biopsies, which enable the analysis oftumour components in patient blood or urine. Effective diagnostics using liquid biopsies willrequire a multifaceted approach, and a recent high-profile review discussed combining multipleanalytes, including changes to the tumour transcriptome, epigenome, proteome, and metabolome.However, the concentration on genomics-based paramaters for analysing liquid biopsies ispotentially missing a goldmine. Glycans have shown huge promise as disease biomarkers, anddata suggests that integrating biomarkers across multi-omic platforms (including changes to theglycome) can improve the stratification of patients with prostate cancer. A wide range ofalterations to glycans have been observed in prostate cancer, including changes to PSAglycosylation, increased sialylation and core fucosylation, increased O-GlcNacylation, theemergence of cryptic and branched N-glyans, and changes to galectins and proteoglycans. In thisreview, we discuss the huge potential to exploit glycans as diagnostic and prognostic biomarkersfor prostate cancer, and argue that the inclusion of glycans in a multi-analyte liquid biopsy test forprostate cancer will help maximise clinical utility.

The glycosylation landscape of pancreatic cancer

Pancreatic adenocarcinoma is a lethal disease with a 5-year survival rate of <5%, the lowest of all types of cancer. The diagnosis of pancreatic cancer relies on imaging and tissue biopsy, and the only curative therapy is complete surgical resection. Pancreatic cancer has the propensity to metastasise at an early stage and the majority of patients are diagnosed when surgery is no longer an option. Hence, there is an urgent need to identify biomarkers to enable early diagnosis, and to develop new therapeutic strategies. One approach for this involves targeting cancer-associated glycans. The most widely used serological marker in pancreatic cancer is the carbohydrate antigen CA 19-9 which contains a glycan known as sialyl Lewis A (sLeA). The CA 19-9 assay is used routinely to monitor response to treatment, but concerns have been raised about its sensitivity and specificity as a diagnostic biomarker. In addition to sLeA, a wide range of alterations to other important glycans have been observed in pancreatic cancer. These include increases in the sialyl Lewis X antigen (sLex), an increase in truncated O-glycans (Tn and sTn), increased branched and fucosylated N-glycans, upregulation of specific proteoglycans and galectins, and increased O-GlcNAcylation. Growing evidence supports crucial roles for glycans in all stages of cancer progression, and it is well established that glycans regulate tumour proliferation, invasion and metastasis. The present review describes the biological significance of glycans in pancreatic cancer, and discusses the clinical value of exploiting aberrant glycosylation to improve the diagnosis and treatment of this deadly disease.

MiR-154 inhibits the growth of laryngeal squamous cell carcinoma by targeting GALNT7

MicroRNAs are critical regulators of the development and progression of laryngeal squamous cell carcinoma (LSCC). However, the role of microRNA-154 (miR-154) in the development and progression of LSCC has not been clarified. We found that down-regulated miR-154 expression in LSCC tissues was associated with poorer prognosis in LSCC patients. MiR-154 over-expression inhibited the proliferation, clonogenicity, and migration of LSCC cells and induced cell cycle arrest, which were reversed by miR-154 inhibition. MiR-154 targeted GALNT7 expression by reducing GALNT7-regulated luciferase activity in LSCC cells while up-regulating GALNT7 mRNA transcription in LSCC tissues and cells. GALNT7 silencing significantly attenuated the proliferation, clonogenicity, and migration of LSCC cells and induced cell cycle arrest. Finally, intravenous treatment with lentivirus for miR-154, but not scrambled control miRNA, significantly restrained the growth of implanted LSCC Hep-2 tumors and decreased the tumor mass by reducing GALNT7 expression in mice. Therefore, miR-154 may serve as a novel prognostic marker and therapeutic target for LSCC.

Roles of CSGalNAcT1, a key enzyme in regulation of CS synthesis, in neuronal regeneration and plasticity

Chondroitin sulfate (CS) is a sulfated glycosaminoglycan composed of a long chain of repeating disaccharide units that are attached to core proteins, resulting in CS proteoglycans (CSPGs). In the mature brain, CS is concentrated in perineuronal nets (PNNs), which are extracellular structures that surround synapses and regulate synaptic plasticity. In addition, CS is rapidly synthesized after CNS injury to create a physical and chemical barrier that inhibits axon growth. Most previous studies used a bacterial CS-degrading enzyme to investigate the physiological roles of CS. Recent studies have shown that CS is synthesized by more than 15 enzymes, all of which have been characterized in vitro. Here we focus on one of those enzymes, CSGalNAcT1 (T1). We produced T1 knockout mice (KO), which show extensive axon regeneration following spinal cord injury, as well as the loss of onset of ocular dominance plasticity. These results from T1KO mice suggest important roles for extracellular CS in the brain regarding neuronal plasticity and axon regeneration.