Expression of spermidine/spermine N(1) -acetyl transferase (SSAT) in human prostate tissues is related to prostate cancer progression and metastasis

Supramolecular fluorescent probe based on acyclic cucurbituril for detection of cancer Labels in human urine

Spermine (Spm) and spermidine (Spmd) are considered as potential biomarker for early diagnosis of human cancer. Herein, a novel acyclic cucurbituril derivative (UL-ACB) was firstly designed and synthesized, which fluoresces at 460 nm after excitation at 365 nm. UL-ACB is rich in oxygen atoms which are capable of forming coordinate bonds with copper (Cu²⁺) that cause quenching of UL-ACB fluorescence. Moreover, the addition of biological endogenous substances Spm and Spmd can turn on fluorescence of UL-ACB. Interestingly, the probe showed a remarkable detection efficiency for Spm and Spmd in human urine (the detection limits of Spm and Spmd were 0.156 μM and 0.762 μM, and the linear ranges are 0.156 ∼ 43.06 μM and 0.762 ∼ 29.10 μM), which completely covered the early diagnosis of urinary Spm (1 ∼ 10 μM) and urine Spmd (1 ∼ 20 μM) required concentration range in cancer patients. The probe for Spm and Spmd is simple, time-saving and selective, which may provide a new promising strategy for early cancer diagnosis.

Prediction of recurrence from metabolites and expression of TOP2A and EZH2 in prostate cancer patients treated with radiotherapy

BACKGROUND

The dual upregulation of TOP2A and EZH2 gene expression has been proposed as a biomarker for recurrence in prostate cancer patients to be treated with radical prostatectomy. A low tissue level of the metabolite citrate has additionally been connected to aggressive disease and recurrence in this patient group. However, for radiotherapy prostate cancer patients, few prognostic biomarkers have been suggested. The main aim of this study was to use an integrated tissue analysis to evaluate metabolites and expression of TOP2A and EZH2 as predictors for recurrence among radiotherapy patients.

METHODS

From 90 prostate cancer patients (56 received neoadjuvant hormonal treatment), 172 transrectal ultrasound-guided (TRUS) biopsies were collected prior to radiotherapy. Metabolic profiles were acquired from fresh frozen TRUS biopsies using high resolution-magic angle spinning MRS. Histopathology and immunohistochemistry staining for TOP2A and EZH2 were performed on TRUS biopsies containing cancer cells (n = 65) from 46 patients, where 24 of these patients (n = 31 samples) received hormonal treatment. Eleven radical prostatectomy cohorts of a total of 2059 patients were used for validation in a meta-analysis.

RESULTS

Among radiotherapy patients with up to 11 years of follow-up, a low level of citrate was found to predict recurrence, p = 0.001 (C-index = 0.74). Citrate had a higher predictive ability compared with individual clinical variables, highlighting its strength as a potential biomarker for recurrence. The dual upregulation of TOP2A and EZH2 was suggested as a biomarker for recurrence, particularly for patients not receiving neoadjuvant hormonal treatment, p = 0.001 (C-index = 0.84). While citrate was a statistically significant biomarker independent of hormonal treatment status, the current study indicated a potential of glutamine, glutamate and choline as biomarkers for recurrence among patients receiving neoadjuvant hormonal treatment, and glucose among patients not receiving neoadjuvant hormonal treatment.

CONCLUSION

Using an integrated approach, our study shows the potential of citrate and the dual upregulation of TOP2A and EZH2 as biomarkers for recurrence among radiotherapy patients.

MYC-driven U2SURP regulates alternative splicing of SAT1 to promote triple-negative breast cancer progression

Triple-negative breast cancer (TNBC), although highly lethal, lacks validated therapeutic targets. Here, we report that U2 snRNP-associated SURP motif-containing protein (U2SURP), a poorly defined member of the serine/arginine rich protein family, was significantly upregulated in TNBC tissues, and its high expression was associated with poor prognosis of TNBC patients. MYC, a frequently amplified oncogene in TNBC tissues, enhanced U2SURP translation through an eIF3D (eukaryotic translation initiation factor 3 subunit D)-dependent mechanism, resulting in the accumulation of U2SURP in TNBC tissues. Functional assays revealed that U2SURP played an important role in facilitating tumorigenesis and metastasis of TNBC cells both in vitro and in vivo. Intriguingly, U2SURP had no significant effects on proliferative, migratory, and invasive potential of normal mammary epithelial cells. Furthermore, we found that U2SURP promoted alternative splicing of spermidine/spermine N1-acetyltransferase 1 (SAT1) pre-mRNA by removal of intron 3, resulting in an increase in the stability of SAT1 mRNA and subsequent protein expression levels. Importantly, spliced SAT1 promoted the oncogenic properties of TNBC cells, and re-expression of SAT1 in U2SURP-depleted cells partially rescued the impaired malignant phenotypes of TNBC cells caused by U2SURP knockdown both in vitro and in mice. Collectively, these findings reveal previously unknown functional and mechanism roles of the MYC-U2SURP-SAT1 signaling axis in TNBC progression and highlight U2SURP as a potential therapy target for TNBC.

Application of gold nanoparticles to determine spermine in the presence of other polyamines

The development of methods for the detection of polyamines in biological fluids is essential to improve early diagnosis and treatment of patients with prostate cancer. One of the promising areas is the use of noble metal nanoparticles. According to the literature data, there is no methodological approach have been developed to reliably distinguish spermine from other polyamines, in particular, from their acetylated forms and related compounds present in biological fluids. The paper presents the results of spectrophotometric determination of spermine both alone and in the presence of putrescine, spermidine or urea in the urine using gold nanoparticles. The results of the experiments proved that the developed method is suitable for the selective determination of spermine. It was shown that the presence of spermidine, putrescine, acetylated forms of polyamines or carbamide does not affect the results of the analysis.

The Association between Spermidine/Spermine N1-Acetyltransferase (SSAT) and Human Malignancies

Spermidine/spermine N¹-acetyltransferase (SSAT) functions as a critical enzyme in maintaining the homeostasis of polyamines, including spermine, spermidine, and putrescine, in mammalian cells. SSAT is a catalytic enzyme that indirectly regulates cellular physiologies and pathways through interaction with endogenous and exogenous polyamines. Normally, SSAT exhibits only at a low cellular level, but upon tumorigenesis, the expression, protein level, and activities of SSAT are altered. The alterations induce cellular damages, including oxidative stress, cell cycle arrest, DNA dynamics, and proliferation by influencing cellular mechanisms and signaling pathways. The expression of SSAT has been reported in various studies to be altered in different cancers, and it has been correlated with tumor development and progression. Tumor grades and stages are associated with the expression levels of SSAT. SSAT can be utilized as a target for substrate binding, and excreted metabolites may be used as a novel cancer biomarker. There is also potential for SSAT to be developed as a therapeutic target. Polyamine analogs could increase SSAT expression and increase the cytotoxicity of chemotherapy to tumor cells. Drugs targeting polyamines and SSAT expression have the potential to be developed into new cancer treatments in the future.

A Novel Artificial Intelligence-Powered Method for Prediction of Early Recurrence of Prostate Cancer After Prostatectomy and Cancer Drivers

PURPOSE

To develop a novel artificial intelligence (AI)-powered method for the prediction of prostate cancer (PCa) early recurrence and identification of driver regions in PCa of all Gleason Grade Group (GGG).

MATERIALS AND METHODS

Deep convolutional neural networks were used to develop the AI model. The AI model was trained on The Cancer Genome Atlas Prostatic Adenocarcinoma (TCGA-PRAD) whole slide images (WSI) and data set (n = 243) to predict 3-year biochemical recurrence after radical prostatectomy (RP) and was subsequently validated on WSI from patients with PCa (n = 173) from the University of Wisconsin-Madison.

RESULTS

Our AI-powered platform can extract visual and subvisual morphologic features from WSI to identify driver regions predictive of early recurrence of PCa (regions of interest [ROIs]) after RP. The ROIs were ranked with AI-morphometric scores, which were prognostic for 3-year biochemical recurrence (area under the curve [AUC], 0.78), which is significantly better than the GGG overall (AUC, 0.62). The AI-morphometric scores also showed high accuracy in the prediction of recurrence for low- or intermediate-risk PCa-AUC, 0.76, 0.84, and 0.81 for GGG1, GGG2, and GGG3, respectively. These patients could benefit the most from timely adjuvant therapy after RP. The predictive value of the high-scored ROIs was validated by known PCa biomarkers studied. With this focused biomarker analysis, a potentially new STING pathway-related PCa biomarker-TMEM173-was identified.

CONCLUSION

Our study introduces a novel approach for identifying patients with PCa at risk for early recurrence regardless of their GGG status and for identifying cancer drivers for focused evolution-aware novel biomarker discovery.

The Potential Role of Spermine and Its Acetylated Derivative in Human Malignancies

Polyamines are essential biomolecules for normal cellular metabolism in humans. The roles of polyamines in cancer development have been widely discussed in recent years. Among all, spermine alongside with its acetylated derivative, N¹, N¹²-Diacetylspermine, demonstrate a relationship with the diagnosis and staging of various cancers, including lung, breast, liver, colorectal and urogenital. Numerous studies have reported the level of spermine in different body fluids and organ tissues in patients with different types of cancers. Currently, the role and the underlying mechanisms of spermine in cancer development and progression are still under investigation. This review summarized the roles of spermine in cancer development and as a diagnostic, prognostic and therapeutic tool in various cancers.

Circulating acetylated polyamines correlate with Covid-19 severity in cancer patients

Cancer patients are particularly susceptible to the development of severe Covid-19, prompting us to investigate the serum metabolome of 204 cancer patients enrolled in the ONCOVID trial. We previously described that the immunosuppressive tryptophan/kynurenine metabolite anthranilic acid correlates with poor prognosis in non-cancer patients. In cancer patients, we observed an elevation of anthranilic acid at baseline (without Covid-19 diagnosis) and no further increase with mild or severe Covid-19. We found that, in cancer patients, Covid-19 severity was associated with the depletion of two bacterial metabolites, indole-3-proprionate and 3-phenylproprionate, that both positively correlated with the levels of several inflammatory cytokines. Most importantly, we observed that the levels of acetylated polyamines (in particular N1-acetylspermidine, N1,N8-diacetylspermidine and N1,N12-diacetylspermine), alone or in aggregate, were elevated in severe Covid-19 cancer patients requiring hospitalization as compared to uninfected cancer patients or cancer patients with mild Covid-19. N1-acetylspermidine and N1,N8-diacetylspermidine were also increased in patients exhibiting prolonged viral shedding (>40 days). An abundant literature indicates that such acetylated polyamines increase in the serum from patients with cancer, cardiovascular disease or neurodegeneration, associated with poor prognosis. Our present work supports the contention that acetylated polyamines are associated with severe Covid-19, both in the general population and in patients with malignant disease. Severe Covid-19 is characterized by a specific metabolomic signature suggestive of the overactivation of spermine/spermidine N1-acetyl transferase-1 (SAT1), which catalyzes the first step of polyamine catabolism.

LINC00265 targets miR-382-5p to regulate SAT1, VAV3 and angiogenesis in osteosarcoma

We explored the mechanism by which LINC00265 regulates angiogenesis of osteosarcoma cells via the miR-382-5p/spermidine/spermine N1-acetyltransferase-1 (SAT1) and miR-382-5p/vav guanine nucleotide exchange factor 3 (VAV3) axis. Cell scratch assay, Transwell assay and tube formation assay were applied to detect cell migration, invasion and tube formation abilities. The effects of LINC00265 targeting miR-382-5p in osteosarcoma in vivo were studied using a tumour-burden assay. A total of 70 genes potentially involved in osteosarcoma angiogenesis were identified, and a Gene Ontology (GO) analysis found that SAT1 and VAV3 were closely related to angiogenesis. Bioinformatics analysis and clinical experiments confirmed that LINC00265, SAT1 and VAV3 were overexpressed in osteosarcoma and related to a poor prognosis, whereas miR-382-5p was downregulated and associated with a poor prognosis. It was confirmed that LINC00265 promoted the proliferation, migration, invasion and angiogenesis of osteosarcoma cells by targeting miR-382-5p to mediate SAT1 and VAV3. Collectively, LINC00265 might promote proliferation, migration, invasion and angiogenesis by targeting miR-382-5p/SAT1 and miR-382-5p/VAV3 in osteosarcoma.

Comprehensive metabolomics analysis of prostate cancer tissue in relation to tumor aggressiveness and TMPRSS2-ERG fusion status

Background

Prostate cancer (PC) can display very heterogeneous phenotypes ranging from indolent asymptomatic to aggressive lethal forms. Understanding how these PC subtypes vary in their striving for energy and anabolic molecules is of fundamental importance for developing more effective therapies and diagnostics. Here, we carried out an extensive analysis of prostate tissue samples to reveal metabolic alterations during PC development and disease progression and furthermore between TMPRSS2-ERG rearrangement-positive and -negative PC subclasses.

Methods

Comprehensive metabolomics analysis of prostate tissue samples was performed by non-destructive high-resolution magic angle spinning nuclear magnetic resonance (¹H HR MAS NMR). Subsequently, samples underwent moderate extraction, leaving tissue morphology intact for histopathological characterization. Metabolites in tissue extracts were identified by ¹H/³¹P NMR and liquid chromatography-mass spectrometry (LC-MS). These metabolomics profiles were analyzed by chemometric tools and the outcome was further validated using proteomic data from a separate sample cohort.

Results

The obtained metabolite patterns significantly differed between PC and benign tissue and between samples with high and low Gleason score (GS). Five key metabolites (phosphocholine, glutamate, hypoxanthine, arginine and α-glucose) were identified, who were sufficient to differentiate between cancer and benign tissue and between high to low GS. In ERG-positive PC, the analysis revealed several acylcarnitines among the increased metabolites together with decreased levels of proteins involved in β-oxidation; indicating decreased acyl-CoAs oxidation in ERG-positive tumors. The ERG-positive group also showed increased levels of metabolites and proteins involved in purine catabolism; a potential sign of increased DNA damage and oxidative stress.

Conclusions

Our comprehensive metabolomic analysis strongly indicates that ERG-positive PC and ERG-negative PC should be considered as different subtypes of PC; a fact requiring different, sub-type specific treatment strategies for affected patients.

Cross-Platform Comparison of Computer-assisted Image Analysis Quantification of In Situ mRNA Hybridization in Investigative Pathology

Although availability of automated platforms has proliferated, there is no standard practice for computer-assisted generation of scores for mRNA in situ hybridization (ISH) visualized by brightfield microscopic imaging on tissue sections. To address this systematically, an ISH for peptidylprolyl isomerase B (PPIB) (cyclophilin B) mRNA was optimized and applied to a tissue microarray of archival non-small cell lung carcinoma cases, and then automated image analysis for PPIB was refined across 4 commercially available software platforms. Operator experience and scoring results from ImageScope, HALO, CellMap, and Developer XD were systematically compared with each other and to manual pathologist scoring. Markup images were compared and contrasted for accuracy, the ability of the platform to identify cells, and the ease of visual assessment to determine appropriate interpretation. Comparing weighted scoring approaches using H-scores (Developer XD, ImageScope, and manual scoring) a correlation was observed (R value=0.7955), and association between the remaining 2 approaches (HALO and CellMap) was of similar value. ImageScope showed the highest R value in comparison with manual scoring (0.7377). Mean-difference plots showed that HALO produced the highest relative normalized values, suggesting higher relative sensitivity. ImageScope overestimated PPIB ISH signal at the high end of the range scores; however, this tendency was not observed in other platforms. HALO emerged with the highest number of favorable observations, no apparent systematic bias in score generation compared with the other methods, and potentially higher sensitivity to detect ISH. HALO may serve as a tool to empower teams of investigative pathology laboratory scientists to assist pathologists readily with quantitative scoring of ISH.

Pharmacological polyamine catabolism upregulation with methionine salvage pathway inhibition as an effective prostate cancer therapy

Prostatic luminal epithelial cells secrete high levels of acetylated polyamines into the prostatic lumen, sensitizing them to perturbations of connected metabolic pathways. Enhanced flux is driven by spermidine/spermine N1-acetyltransferase (SSAT) activity, which acetylates polyamines leading to their secretion and drives biosynthetic demand. The methionine salvage pathway recycles one-carbon units lost to polyamine biosynthesis to the methionine cycle to overcome stress. Prostate cancer (CaP) relies on methylthioadenosine phosphorylase (MTAP), the rate-limiting enzyme, to relieve strain. Here, we show that inhibition of MTAP alongside SSAT upregulation is synergistic in androgen sensitive and castration recurrent CaP models in vitro and in vivo. The combination treatment increases apoptosis in radical prostatectomy ex vivo explant samples. This unique high metabolic flux through polyamine biosynthesis and connected one carbon metabolism in CaP creates a metabolic dependency. Enhancing this flux while simultaneously targeting this dependency in prostate cancer results in an effective therapeutic approach potentially translatable to the clinic.

Prostate cancer cells depend on MTAP, the rate-limiting enzyme involved in the methionine salvage pathway, to cope with increased polyamine biosynthesis. Here, the authors show that inducing upregulation of polyamine biosynthesis and targeting MTAP synergize to increase apoptosis in prostate cancer cells.

Liquid Biopsy in Lung Cancer Screening: The Contribution of Metabolomics. Results of A Pilot Study

Background: Lung cancer is the most common cause of cancer-related deaths worldwide. Early diagnosis is crucial to increase the curability chance of the patients. Low dose CT screening can reduce lung cancer mortality, but it is associated with several limitations. Metabolomics is a promising technique for cancer diagnosis due to its ability to provide chemical phenotyping data. The intent of our study was to explore metabolomic effects and profiles of lung cancer patients to determine if metabolic perturbations in the SSAT-1/polyamine pathway can distinguish between healthy participants and lung cancer patients as a diagnostic and treatment monitoring tool. Patients and Methods: Plasma samples were collected as part of the SSAT1 Amantadine Cancer Study. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify and quantify metabolite concentrations in lung cancer patient and control samples. Standard statistical analyses were performed to determine whether metabolite concentrations could differentiate between healthy subjects and lung cancer patients, as well as risk prediction modeling applied to determine whether metabolic profiles could provide an indication of cancer progression in later stage patients. Results: A panel consisting of 14 metabolites, which included 6 metabolites in the polyamine pathway, was identified that correctly discriminated lung cancer patients from controls with an area under the curve of 0.97 (95% CI: 0.875-1.0). Conclusion: When used in conjunction with the SSAT-1/polyamine pathway, these metabolites may provide the specificity required for diagnosing lung cancer from other cancer types and could be used as a diagnostic and treatment monitoring tool.

Predictive value and clinical significance of increased SSAT-1 activity in healthy adults

AIM

Spermidine/spermine N1-acetyltransferase (SSAT-1) regulates cell growth, proliferation and death. Amantadine is converted by SSAT-1 to acetylamantadine (AA). In our earlier studies, although SSAT-1 was activated in patients with cancer, a number of ostensibly healthy adult volunteers had higher than expected AA concentration. This study was therefore undertaken to examine the outlier group.

MATERIALS & METHODS

A follow up of urine analysis for AA by liquid chromatography-tandem mass spectrometry as well as clinical assessments and additional blood analyses were conducted.

RESULTS

In some of the outlier controls, higher than expected AA concentration was linked to increased serum carcinoembryonic antigen. Clinical and radiographic assessments revealed underlying abnormalities in other cases that could represent premalignant conditions. Hematology tests revealed elevations in white blood cells and platelets, which are markers of inflammation.

CONCLUSION

High urine concentration of AA could be used as a simple and useful test for screening of cancer in high-risk populations.

Biological functions of circular RNAs and their roles in occurrence of reproduction and gynecological diseases

Circular RNAs (circRNAs) are a large class of non coding endogenous RNAs in eukaryotic that are formed through 3'-5' ligation of a single RNA molecule. According to the different sources of the sequences, circRNA can be divided into three types: exon circRNA (ecRNA), intron circRNA (ciRNA), and exon-intron circRNA. Accumulating studies have shown that circRNAs are abundant, diverse, stable, and cell or tissue specific expression, etc. CircRNA plays a regulating role in gene expression, and an essential role in the process of biological development, such as miRNA sponges, endogenous RNAs and biomarkers, as well as critical role in the diagnosis of diseases. Studies have verified the interplay between circRNAs and the development of embryos, sperms, ovarian epithelial tumors, endometrial cancer and preeclampsia, suggesting the potential of circRNAs to become biomarkers or therapeutical targets for human diseases. In this paper, we reviewed the researches on circRNAs' characteristics, databases of circRNA, high-throughput sequencing of circRNA, and effect on reproductive and gynecological diseases.

Use of amantadine as substrate for SSAT-1 activity as a reliable clinical diagnostic assay for breast and lung cancer

Aim:

Spermidine/spermine N¹-acetyltransferase (SSAT-1) plays a critical role in cell growth, proliferation and death, and is known to be activated in human cancer cells. Amantadine, a US FDA-approved antiviral drug, is a substrate for SSAT-1 and can be used to indirectly measure SSAT-1 activity because of its conversion to acetylamantadine (AA). This study was undertaken to further validate SSAT-1 activity in breast and lung cancer patients.

Results:

An increase in the urinary concentration of AA in lung and breast cancer patients was observed. The 0–2 h collection time point was determined to be optimal in revealing significant differences in urinary AA concentration between healthy controls and cancer patients.

Conclusion:

The high urine concentration of AA could be used as a simple and useful test for the detection of breast and lung cancer.

This study describes a novel noninvasive urine test for detecting and screening of breast and lung cancer using a safe and approved drug called amantadine. Higher concentration of the acetylated form of amantadine in the urine are detectable in the urine of both breast and lung cancer patients as compared with healthy adult volunteers. This test is simple and may serve as a useful tool for determining the presence of breast and lung cancer.

Spermidine/spermine N1-acetyltransferase-1 as a diagnostic biomarker in human cancer

Aim:

SSAT-1 is an enzyme that plays a critical role in cell growth. Amantadine, a FDA-approved antiviral drug, is a substrate for SSAT-1. The utility of amantadine as an agent to demonstrate elevated SSAT-1 activity linked to cancer was conducted.

Results:

High levels of SSAT-1 expression were measured in tumor human cell lines, and in breast, prostate and lung tumor tissue. An increase in the urinary levels of acetylated amantadine in cancer patients was observed.

Conclusion:

Increases in SSAT-1 contents in tumor tissue could be of value in targeting cancers with high SSAT-1 expression for confirmation/quantification. The high levels of acetylated amantadine could be used as a simple and useful screening test for the presence of cancer.

In response to cancer, cells tend to overproduce specific enzymes as a self-defense mechanism. By using a safe and reliable method to capture and measure the excess enzyme spermidine/spermine N1-acetyltransferase-1, the presence of cancer can be established. This study describes a novel approach of detecting and screening cancer noninvasively in the urine of cancer patients using a safe and approved drug called amantadine that acts as a smart-tracking agent. Higher levels of the acetylated form of amantadine are detectable in the urine of cancer patients, which may serve as a detection tool. In addition, increases in the amount of spermidine/spermine N1-acetyltransferase-1 in tumor tissue may provide a tool for determining the presence of cancer during pathology assessment.

Characterization of the SSAT1 gene and its expression profiling in various tissues and follicles in geese

Spermidine/spermine N1-acetyltransferase (SSAT ) is a catabolic regulator of polyamines, ubiquitous molecules essential for cell proliferation and differentiation. In this study, the molecular characterization of the SSAT1 gene of the Sichuan white goose was analyzed, as well as its expression profiles in various follicles and tissues. The open reading frame of the SSAT1 cDNA (GenBank No. KM925008) is 516 bp in length and encodes a 171-amino acid protein with a putative molecular weight of 20 kDa. The predicted SSAT1 protein is highly conserved with those of other species, especially Gallus gallus. SSAT1 mRNA was ubiquitously expressed in all the examined tissues. The highest level of SSAT1 mRNA expression was found in the pineal gland (P<0.05), and was 12-fold greater than in the heart. The level of SSAT1 mRNA expression was relatively lower in preovulatory follicles, while it was higher in postovulatory follicles (POFs), particularly in POF1. Furthermore, as postovulatory follicles degenerated, SSAT1 expression gradually decreased. Our findings suggest that SSAT1 might play important roles in mediating the physiological function of the pineal gland and regulating the regression of POFs.

The old and new biochemistry of polyamines

Polyamines are ubiquitous positively charged amines found in all organisms. These molecules play a crucial role in many biological functions including cell growth, gene regulation and differentiation. The three major polyamines produced in all mammalian cells are putrescine, spermidine and spermine. The intracellular levels of these polyamines depend on the interplay of the biosynthetic and catabolic enzymes of the polyamine and methionine salvage pathway, as well as the involvement of polyamine transporters. Polyamine levels are observed to be high in cancer cells, which contributes to malignant transformation, cell proliferation and poor patient prognosis. Considering the critical roles of polyamines in cancer cell proliferation, numerous anti-polyaminergic compounds have been developed as anti-tumor agents, which seek to suppress polyamine levels by specifically inhibiting polyamine biosynthesis, activating polyamine catabolism, or blocking polyamine transporters. However, in terms of the development of effective anti-cancer therapeutics targeting the polyamine system, these efforts have unfortunately resulted in little success. Recently, several studies using the iron chelators, O-trensox and ICL670A (Deferasirox), have demonstrated a decline in both iron and polyamine levels. Since iron levels are also high in cancer cells, and like polyamines, are required for proliferation, these latter findings suggest a biochemically integrated link between iron and polyamine metabolism.

Expression of the SIBLINGs and their MMP partners in human benign and malignant prostate neoplasms

The small integrin binding ligands n-linked glycoproteins (SIBLINGs) have emerged as potential diagnostic and prognostic indices, and as key targets, in cancer therapy. Three members of the SIBLING family: bone sialoprotein (BSP); osteopontin (OPN); and dentin matrix protein1 (DMP1), bind and interact with specific matrix metalloproteinases (MMPs): BSP-MMP2; OPN-MMP3; DMP1-MMP9, in biochemical and biologic systems. The other two family members are dentin sialophosphoprotein (DSPP) and matrix extracellular phosphoglycoprotein (MEPE). The specific SIBLING-MMP pairing reported in some cancers have not been reported in prostate neoplasms. In this study, we investigated SIBLING-MMP expression and potential interaction in prostate neoplasms. Chi square analysis of immunohistochemistry results showed significant upregulation of OPN (X2=25.710/p<0.001), BSP (X2=19.546/p<0.001), and DSPP (X2=8.720/p=0.003) in prostate adenocarcinoma (pAdC). MEPE was significantly upregulated in benign prostate hyperplasia (BPH; X2=44.153/p<0.001). There were no significant differences in MMP expression between BPH and pAdC. Western blot analysis showed significantly elevated BSP and DSPP in prostate cancer-derived cells. Immunofluorescence studies confirmed BSP-MMP2, OPN-MMP3, and DMP1-MMP9 coexpression in two cancer-derived cell lines, whereas in situ proximity ligation assays confirmed potential BSP-MMP2, OPN-MMP3, and DMP1-MMP9 interactions in BPH and pAdC. Our reports provide evidence that SIBLING-MMP interaction may play a role in the progression of BPH to pAdC.

Long Non-coding RNA Linc-ROR Is Upregulated in Papillary Thyroid Carcinoma

Long non-coding RNAs (lncRNAs) may contribute to carcinogenesis and tumor progression by regulating transcription and gene expression. The role of lncRNAs in the regulation of thyroid cancer progression is being extensively examined. Here, we analyzed three lncRNAs that were overexpressed in papillary thyroid carcinomas, long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR, ROR) PVT1 oncogene (PVT1), and HOX transcript antisense intergenic RNA (HOTAIR) to determine their roles in thyroid tumor development and progression. ROR expression has not been previously examined in thyroid carcinomas. Tissue microarrays (TMAs) of formalin-fixed paraffin-embedded tissue sections from 129 thyroid cases of benign and malignant tissues were analyzed by in situ hybridization (ISH), automated image analysis, and real-time PCR. All three lncRNAs were most highly expressed in the nuclei of PTCs. SiRNA experiments with a PTC cell line, TPC1, showed inhibition of proliferation with siRNAs for all three lncRNAs while invasion was inhibited with siRNAs for ROR and HOTAIR. SiRNA experiments with ROR also led to increased expression of miR-145, supporting the role of ROR as an endogenous miR-145 sponge. After treatment with TGF-β, there was increased expression of ROR, PVT1, and HOTAIR in the PTC1 cell line compared to control groups, indicating an induction of their expression during epithelial to mesenchymal transition (EMT). These results indicate that ROR, PVT1, and HOTAIR have important regulatory roles during the development of PTCs.

Extracellular polyamines-induced proliferation and migration of cancer cells by ODC, SSAT, and Akt1-mediated pathway

High levels of polyamines were observed and were related to a poor prognosis in cancer patients. However, the mechanism is not obvious. The aim of this study is to mimic the extracellular polyamines in a tumor microenviroment and to explore the role of extracellular polyamines in the proliferation and migration of cancer cells. Three different concentrations of polyamines composed of putrescine, spermidine, and spermine were used. Colony formation assay, wound healing assay, and transwell migration assay were performed. Akt1-overexpression cells were constructed. The related protein expression was examined using a western blot. In this study, polyamines promoted colony formation and cell migration in a concentration-dependent and time-dependent manner. Polyamines upregulated the expression of ornithine decarboxylase (ODC), SSAT, Akt1, Akt, hypoxia-inducible factors-1α, vascular endothelial growth factor, and matrix metalloproteinases, and downregulated p27 expression. The effects of combination of polyamines and Akt1 overexpression on colony formation and migration were more obvious than the effects of Akt1 overexpression alone. In Akt1-overexpression cells, polyamines also upregulated the expression of ODC, SSAT, hypoxia-inducible factors-1α, vascular endothelial growth factor, and matrix metalloproteinases and downregulated p27 expression. In conclusion, extracellular polyamines induced proliferation and cancer cell migration by inducing ODC and SSAT expression, and the Akt1-mediated pathway.

Ex vivo metabolic fingerprinting identifies biomarkers predictive of prostate cancer recurrence following radical prostatectomy

Background:

Robust biomarkers that identify prostate cancer patients with high risk of recurrence will improve personalised cancer care. In this study, we investigated whether tissue metabolites detectable by high-resolution magic angle spinning magnetic resonance spectroscopy (HR-MAS MRS) were associated with recurrence following radical prostatectomy.

Methods:

We performed a retrospective ex vivo study using HR-MAS MRS on tissue samples from 110 radical prostatectomy specimens obtained from three different Norwegian cohorts collected between 2002 and 2010. At the time of analysis, 50 patients had experienced prostate cancer recurrence. Associations between metabolites, clinicopathological variables, and recurrence-free survival were evaluated using Cox proportional hazards regression modelling, Kaplan–Meier survival analyses and concordance index (C-index).

Results:

High intratumoural spermine and citrate concentrations were associated with longer recurrence-free survival, whereas high (total-choline+creatine)/spermine (tChoCre/Spm) and higher (total-choline+creatine)/citrate (tChoCre/Cit) ratios were associated with shorter time to recurrence. Spermine concentration and tChoCre/Spm were independently associated with recurrence in multivariate Cox proportional hazards modelling after adjusting for clinically relevant risk factors (C-index: 0.769; HR: 0.72; P=0.016 and C-index: 0.765; HR: 1.43; P=0.014, respectively).

Conclusions:

Spermine concentration and tChoCre/Spm ratio in prostatectomy specimens were independent prognostic markers of recurrence. These metabolites can be noninvasively measured in vivo and may thus offer predictive value to establish preoperative risk assessment nomograms.

Oxidative stress and prostatic diseases

Prostatic diseases are a common health problem among males in Western countries, and include chronic prostatic diseases, which have an unclear pathogenesis and few treatment options. In vitro and in vivo studies describe oxidative stress as a major pathway involved in the occurrence of benign prostatic hyperplasia, prostatic cancer and chronic prostatitis. Thus, the oxidative stress cascade is a potential target for the treatment of prostatic diseases. This paper presents a systematic review of the available data concerning the association between oxidative stress and the most common chronic prostatic diseases, and describes the available treatment options that act upon this pathway.

MALAT1 Long Non-coding RNA Expression in Thyroid Tissues: Analysis by In Situ Hybridization and Real-Time PCR

Long non-coding RNAs (lncRNAs) are important for transcription and for epigenetic or posttranscriptional regulation of gene expression and may contribute to carcinogenesis. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), an lncRNA involved in the regulation of the cell cycle, cell proliferation, and cell migration, is known to be deregulated in multiple cancers. Here, we analyzed the expression of MALAT1 on 195 cases of benign and malignant thyroid neoplasms by using tissue microarrays for RNA in situ hybridization (ISH) and real-time PCR. MALAT1 is highly expressed in normal thyroid (NT) tissues and thyroid tumors, with increased expression during progression from NT to papillary thyroid carcinomas (PTCs) but is downregulated in poorly differentiated thyroid cancers (PDCs) and anaplastic thyroid carcinomas (ATCs) compared to NT. Induction of epithelial to mesenchymal transition (EMT) by transforming growth factor (TGF)-beta in a PTC cell line (TPC1) led to increased MALAT1 expression, supporting a role for MALAT1 in EMT in thyroid tumors. This is the first ISH study of MALAT1 expression in thyroid tissues. It also provides the first piece of evidence suggesting MALAT1 downregulation in certain thyroid malignancies. Our findings support the notion that ATCs may be molecularly distinct from low-grade thyroid malignancies and suggest that MALAT1 may function both as an oncogene and as a tumor suppressor in different types of thyroid tumors.

Metabolite Analysis and Histology on the Exact Same Tissue: Comprehensive Metabolomic Profiling and Metabolic Classification of Prostate Cancer

We report a method of metabolomic profiling of intact tissue based on molecular preservation by extraction and fixation (mPREF) and high-performance chemical isotope labeling (CIL) liquid chromatography mass spectrometry (LC-MS). mPREF extracts metabolites by aqueous methanol from tissue biopsies without altering tissue architecture and thus conventional histology can be performed on the same tissue. In a proof-of-principle study, we applied dansylation LC-MS to profile the amine/phenol submetabolome of prostate needle biopsies from 25 patient samples derived from 16 subjects. 2900 metabolites were consistently detected in more than 50% of the samples. This unprecedented coverage allowed us to identify significant metabolites for differentiating tumor and normal tissues. The panel of significant metabolites was refined using 36 additional samples from 18 subjects. Receiver Operating Characteristic (ROC) analysis showed area-under-the-curve (AUC) of 0.896 with sensitivity of 84.6% and specificity of 83.3% using 7 metabolites. A blind study of 24 additional validation samples gave a specificity of 90.9% at the same sensitivity of 84.6%. The mPREF extraction can be readily implemented into the existing clinical workflow. Our method of combining mPREF with CIL LC-MS offers a powerful and convenient means of performing histopathology and discovering or detecting metabolite biomarkers in the same tissue biopsy.

Structure and Functional Diversity of GCN5-Related N-Acetyltransferases (GNAT)

General control non-repressible 5 (GCN5)-related N-acetyltransferases (GNAT) catalyze the transfer of an acyl moiety from acyl coenzyme A (acyl-CoA) to a diverse group of substrates and are widely distributed in all domains of life. This review of the currently available data acquired on GNAT enzymes by a combination of structural, mutagenesis and kinetic methods summarizes the key similarities and differences between several distinctly different families within the GNAT superfamily, with an emphasis on the mechanistic insights obtained from the analysis of the complexes with substrates or inhibitors. It discusses the structural basis for the common acetyltransferase mechanism, outlines the factors important for the substrate recognition, and describes the mechanism of action of inhibitors of these enzymes. It is anticipated that understanding of the structural basis behind the reaction and substrate specificity of the enzymes from this superfamily can be exploited in the development of novel therapeutics to treat human diseases and combat emerging multidrug-resistant microbial infections.

Conformational study and reassessment of the vibrational assignments for Norspermidine

The present study presents and discusses the conformational preferences of Norspermidine (NSpd). The effects of varying the dielectric constant on the conformational preferences are discussed, with a view to infer which conformation will correspond to the most stable in the pure condensed liquid phase. Within the same context, a set of NSpd-NH3 molecular adducts were simulated in order to determine the relevance of intermolecular hydrogen bonding on the overall stability and relative positioning of the respective vibrational frequencies. The calculations presently performed allowed a reassessment of the vibrational assignments for NSpd. A full assignment of the NSpd vibrational spectra is presented, with special emphasis being given to the vibrational modes that proved to be most affected by hydrogen bonding. The various inconsistencies of a prior study found in the literature were identified and rectified.

Non-Coding RNAs in Thyroid Cancer

Non-coding (nc)RNAs are divided into small ncRNAs and long ncRNAs (lncRNAs). MicroRNAs (miRNAs) are small ncRNAS which are around 22 nucleotides in length that mediate post-transcriptional gene silencing. LncRNAs are greater than 200 bp in length. Each ncRNA can have multiple targets and can be regulated by multiple genetic factors. Because ncRNAs are not translated into proteins, they can only be detected at the nucleic acid level by in situ hybridization, by RT-PCR, or by sequencing which makes their detection more challenging in the routine pathology laboratory. A great deal of new information has accumulated about miRNAs in thyroid tissues during the past decade. Some of these studies have shown that deregulation of miRNAs may be useful in diagnostic pathology. Information about the role of lncRNA in the development of thyroid tumors is in the early stages of development, but new information is accumulating rapidly. In this review, we will discuss the recent progress in our understanding of the relationship between ncRNAs and the development of thyroid cancers and the potential uses of ncRNAs in the diagnosis and prognosis of thyroid tumors.

Inhibitor of p52 NF-κB subunit and androgen receptor (AR) interaction reduces growth of human prostate cancer cells by abrogating nuclear translocation of p52 and phosphorylated AR(ser81)

Accumulating evidence shows that androgen receptor (AR) activation and signaling plays a key role in growth and progression in all stages of prostate cancer, even under low androgen levels or in the absence of androgen in the castration-resistant prostate cancer. Sustained activation of AR under androgen-deprived conditions may be due to its interaction with co-activators, such as p52 NF-κB subunit, and/or an increase in its stability by phosphorylation that delays its degradation. Here we identified a specific inhibitor of AR/p52 interaction, AR/p52-02, via a high throughput screen based on the reconstitution of Gaussia Luciferase. We found that AR/p52-02 markedly inhibited growth of both castration-resistant C4-2 (IC50 ∼6 μM) and parental androgen-dependent LNCaP (IC50 ∼4 μM) human prostate cancer cells under low androgen conditions. Growth inhibition was associated with significantly reduced nuclear p52 levels and DNA binding activity, as well as decreased phosphorylation of AR at serine 81, increased AR ubiquitination, and decreased AR transcriptional activity as indicated by decreased prostate-specific antigen (PSA) mRNA levels in both cell lines. AR/p52-02 also caused a reduction in levels of p21(WAF/CIP1), which is a direct AR targeted gene in that its expression correlates with androgen stimulation and mitogenic proliferation in prostate cancer under physiologic levels of androgen, likely by disrupting the AR signaling axis. The reduced level of cyclinD1 reported previously for this compound may be due to the reduction in nuclear presence and activity of p52, which directly regulates cyclinD1 expression, as well as the reduction in p21(WAF/CIP1), since p21(WAF/CIP1) is reported to stabilize nuclear cyclinD1 in prostate cancer. Overall, the data suggest that specifically inhibiting the interaction of AR with p52 and blocking activity of p52 and pARser81 may be an effective means of reducing castration-resistant prostate cancer cell growth.

PTEN mRNA detection by chromogenic, RNA in situ technologies: a reliable alternative to PTEN immunohistochemistry

Immunohistochemical staining for phosphatase and tensin homolog (PTEN) does not have either an acceptable standard protocol or concordance of scoring between pathologists. Evaluation of PTEN mRNA with a unique and verified sequence probe may offer a realistic alternative providing a robust and reproducible protocol. In this study, we have evaluated an in situ hybridization (ISH) protocol for PTEN mRNA using RNAScope technology and compared it with a standard protocol for PTEN immunohistochemistry (IHC). PTEN mRNA expression by ISH was consistently more sensitive than PTEN IHC, with 56% of samples on a mixed-tumor tissue microarray (TMA) showing high expression by ISH compared with 42% by IHC. On a prostate TMA, 49% of cases showed high expression by ISH compared with 43% by IHC. Variations in PTEN mRNA expression within malignant epithelium were quantifiable using image analysis on the prostate TMAs. Within tumors, clear overexpression of PTEN mRNA on malignant epithelium compared with benign epithelium was frequently observed and quantified. The use of SpotStudio software in the mixed-tumor TMA allowed for clear demonstration of varying levels of PTEN mRNA between tumor samples by the mRNA methodology. This was evident by the quantifiable differences between distinct oropharyngeal tumors (up to 3-fold increase in average number of spots per cell between 2 cases). mRNA detection of PTEN or other biomarkers, for which optimal or standardized immunohistochemical techniques are not available, represents a means by which heterogeneity of expression within focal regions of tumor can be explored with more confidence.