Low RNA stability signifies strong expression regulatability of tumor suppressors.

RNA expression of a gene is determined by not only transcriptional regulation, but also post-transcriptional regulation of RNA decay. The precise regulation of RNA stability in the cell plays an important role in normal development. Dysregulation of RNA stability can lead to diseases such as cancer. Here we found tumor suppressor RNAs tended to decay fast in normal cell types when compared with other RNAs. Consistent with a negative effect of m6A modification on RNA stability, we observed preferential deposition of m6A on tumor suppressor RNAs. Moreover, abundant m6A and fast decay of tumor suppressor RNAs both tended to be further enhanced in prostate cancer cells relative to normal prostate epithelial cells. Further, knockdown of m6A methyltransferase METTL3 and reader YTHDF2 in prostate cancer cells both posed stronger effect on tumor suppressor RNAs than on other RNAs. These results indicated a strong post transcriptional expression regulatability mediated by abundant m6A modification on tumor suppressor RNAs.

PTEN Loss and PD-L1 Expression of Different Histological Patterns of Prostate Cancer.

AIMS: Although several studies have evaluated PTEN loss in Prostatic Adenocarcinoma (PCa), PTEN loss correlation with different histological patterns only has a few studies. Although several studies have evaluated PD-L1 expression in PCa and its correlation with Gleason scores, as far as we know, there are no prior studies that have included a comparison between PD-L1 expression and histological patterns of PCa. This study aims to evaluate PTEN loss and PD-L1 expression by immunohistochemistry in different histological patterns of PCa. METHODS: The current study included consecutive 98 radical prostatectomy specimens with 151 foci with different Gleason Grade (GG) patterns. RESULTS: The highest frequency of PTEN loss was observed in GG4 cribriform and glomeruloid patterns (59.3%, p < 0.001). Combined score (CS) PD-L1 positivity was observed in fourteen patients (14.2%). Tumor cell (TC) and tumor-associated inflammatory cells (IC) PD-L1 positivity was observed in 10 (10.2%) and 7 (7.1%) patients. The highest frequency of PD-L1 expression was observed in the GG5 pattern, and between GG4 patterns, the irregular pattern had the highest PD-L1 positivity. CONCLUSIONS: In conclusion, in our cohort of consecutive unselected cases of prostatic carcinoma, we observed the highest PTEN loss rate in the GG4 cribriform and glomeruloid pattern and the highest PD-L1 expression rate in the GG5 and GG4 irregular patterns. These results may predict molecular differences between different histological patterns in PCa and may be used to inform a treatment decision. Future studies should investigate these differences between histological patterns of PCa to predict response to immunotherapy in larger cohorts.

Molecular margin status after radical prostatectomy using glutathione S-transferase P1 (GSTP1) promoter hypermethylation.

OBJECTIVE: To assess the potential for molecular staging in biopsies of the prostatic fossa after radical prostatectomy (RP) by searching for occult tumour cells through analysis of glutathione S-transferase P1 (GSTP1) methylation status. PATIENTS AND METHODS: We analysed 2446 biopsies: 2286 biopsies from a group of 254 patients with clinically organ-confined prostate cancer who underwent RP and 160 biopsies from a control group of 32 patients. After prostate gland excision, biopsies were obtained from defined areas of the prostatic fossa and bisected for histopathological and molecular genetics analyses. Results were related to clinicopathological data including tumour stage, lymph node status, resection status, tumour grading, initial PSA level, and biochemical recurrence. RESULTS: In total, 34 patients (13.4%) had at least one core positive for the GSTP1 promoter hypermethylation, six of whom (17.6%) were characterised as having a clinically localised tumour stage (pT2, pN0) and 28 (82.4%) as an advanced tumour stage (≥pT3 and/or pN1). GSTP1 promoter hypermethylation significantly correlated with tumour stage (P < 0.001), International Society of Urological Pathology grading (P = 0.001), lymph node status (P < 0.001), surgical margin status (P < 0.001), and biochemical recurrence (P = 0.001). Furthermore, in 46 patients (18.1%) further analysis led to a down- or upgrading of conventional surgical margin status. Classical R-status (margins of the specimen) is significantly superior to histological sampling from the fossa (P = 0.006) but not to GSTP1 analysis from the fossa (P = 0.227). CONCLUSION: For the detection of residual tumour in the fossa after RP in order to better predict recurrence, molecular GSTP1 promoter hypermethylation has some value; however, the classical R-status (margins of the specimen) is simpler and more widely applicable with similar results.

Synthesis and Biological Evaluation of S-, O- and Se-Containing Dispirooxindoles.

A series of novel S-, O- and Se-containing dispirooxindole derivatives has been synthesized using 1,3-dipolar cycloaddition reaction of azomethine ylide generated from isatines and sarcosine at the double C=C bond of 5-indolidene-2-chalcogen-imidazolones (chalcogen was oxygen, sulfur or selenium). The cytotoxicity of these dispiro derivatives was evaluated in vitro using different tumor cell lines. Several molecules have demonstrated a considerable cytotoxicity against the panel and showed good selectivity towards colorectal carcinoma HCT116 p53+/+ over HCT116 p53-/- cells. In particular, good results have been obtained for LNCaP prostate cell line. The performed in silico study has revealed MDM2/p53 interaction as one of the possible targets for the synthesized molecules. However, in contrast to selectivity revealed during the cell-based evaluation and the results obtained in computational study, no significant p53 activation using a reporter construction in p53wt A549 cell line was observed in a relevant concentration range.

ADAMTS9-AS2: a potential diagnostic and prognostic hallmark in prostate cancer.

PURPOSE: To explore the expression level and prognostic value of ADAMTS9-AS2 in prostate cancer (PCa). METHODS: ADAMTS9-AS2 levels in 110 paired PCa tissues and adjacent normal tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between ADAMTS9-AS2 level and clinical parameters of PCa was analyzed. ROC (receiver operating characteristics) curves were depicted for assessing the diagnostic value of ADAMTS9-AS2 in PCa. Through collecting 5-year follow-up data of PCa patients, survival analysis was performed by Kaplan-Meier method. Finally, Cox regression model was used to analyze factors affecting outcomes of PCa patients. RESULTS: ADAMTS9-AS2 was downregulated in PCa tissues than in adjacent normal ones. Its level was lower in PCa tissues with clinical stage III+IV or tumor size ≥3cm compared to those with stage I+II or tumor size <3cm. ROC curves verified the diagnostic value of ADAMTS9-AS2 in PCa (AUC=0.902, cut-off value=0.40, sensitivity=90.00%, specificity=79.09%, Youden index=0.6909). Kaplan-Meier method and log-rank test uncovered worse prognosis in PCa patients expressing low level of ADAMTS9-AS2. Clinical stage, tumor size and ADAMTS9-AS2 level were independent factors influencing prognosis of PCa. CONCLUSIONS: ADAMTS9-AS2 is downregulated in PCa and its low level is unfavorable to the disease prognosis. ADAMTS9-AS2 may be utilized as a potential diagnostic and prognostic hallmark of PCa.

High level of phosphatidylcholines/lysophosphatidylcholine ratio in urine is associated with prostate cancer.

The altered levels of phospholipids (PLs) and lysophospholipids (LPLs) in prostate cancer (CaP) and benign tissues in our previous findings prompted us to explore PLs and LPLs as potential biomarkers for CaP. Urinary lipidomics has attracted increasing attention in clinical diagnostics and prognostics for CaP. In this study, 31 prostate tissues obtained from radical prostatectomy were assessed using high-resolution matrix-assisted laser desorption/ionization imaging mass spectrometry (HR-MALDI-IMS). Urine samples were collected after digital rectal examination (DRE), and urinary lipids were extracted using the acidified Bligh-Dyer method. The discovery set comprised 75 patients with CaP and 44 with benign prostatic hyperplasia (BPH) at Kyoto University Hospital; the validation set comprised 74 patients with CaP and 59 with BPH at Osaka University Hospital. Urinary lipidomic screening was performed using MALDI time-of-flight MS (MALDI-TOF/MS). The levels of urinary lysophosphatidylcholine (LPC) and phosphatidylcholines (PCs) were compared between the CaP and BPH groups. The (PC [34:2] + PC [34:1])/LPC (16:0) ratio was significantly higher (P < .001) in CaP tissues than in benign epithelial tissues. The urinary PCs/LPC ratio was significantly higher (P < .001) in the CaP group than in the BPH group in the discovery and validation sets.

Androgen receptor variant shows heterogeneous expression in prostate cancer according to differentiation stage.

Quantitation of androgen receptor variant (AR-V) expression in circulating tumor cells (CTCs) from patients with metastatic castration-resistant prostate cancer (mCRPC) has great potential for treatment customization. However, the absence of a uniform CTC isolation platform and consensus on an analytical assay has prevented the incorporation of these measurements in routine clinical practice. Here, we present a single-CTC sensitive digital droplet PCR (ddPCR) assay for the quantitation of the two most common AR-Vs, AR-V7, and AR-v567es, using antigen agnostic CTC enrichment. In a cohort of 29 mCRPC patients, we identify AR-V7 in 66% and AR-v567es in 52% of patients. These results are corroborated using another gene expression platform (NanoStringTM) and by analysis of RNA-Seq data from patients with mCRPC (SU2C- PCF Dream Team). We next quantify AR-V expression in matching EpCAM-positive vs EpCAM-negative CTCs, as EpCAM-based CTC enrichment is commonly used. We identify lower AR-V prevalence in the EpCAM-positive fraction, suggesting that EpCAM-based CTC enrichment likely underestimates AR-V prevalence. Lastly, using single CTC analysis we identify enrichment for AR-v567es in patients with neuroendocrine prostate cancer (NEPC) indicating that AR-v567es may be involved in lineage plasticity, which warrants further mechanistic interrogation.

Preoperative histogram parameters of dynamic contrast-enhanced MRI as a potential imaging biomarker for assessing the expression of Ki-67 in prostate cancer.

PURPOSE: To investigate whether preoperative histogram parameters of dynamic contrast-enhanced MRI (DCE-MRI) can assess the expression of Ki-67 in prostate cancer (PCa). MATERIALS AND METHODS: A consecutive series of 76 patients with pathology-proven PCa who underwent routine DCE-MRI scans were retrospectively recruited. Quantitative parameters including the volume transfer constant (Ktrans ), rate contrast (Kep ), extracellular-extravascular volume fraction (Ve ), and plasma volume (Vp ) by outlining the three-dimensional volume of interest (VOI) of all lesions were processed. Then, the histogram analyses of these quantitative parameters were performed. The Spearman rank correlation analysis was used to evaluate the correlation of these parameters and Ki-67 expression of PCa. Receiver operating characteristic (ROC) curve analysis was adopted to evaluate the efficacy of these quantitative histogram parameters in identifying high Ki-67 expression from low Ki-67 expression of PCa. RESULTS: Eighty-eight PCa lesions were enrolled in this study, including 31 lesions with high Ki-67 expression and 57 lesions with low Ki-67 expression. The median, mean, 75th percentile, and 90th percentile derived from Ktrans and Kep had a moderately positive correlation with Ki-67 expression (r = 0.361-0.450, p < 0.05), in which both the median and mean of Ktrans had the highest positive correlation (r = 0.450, p < 0.05). The diagnostic efficacy of the Ktrans median, mean, 75th percentile, and 90th percentile, along with the Kep -based median and mean was assessed by the ROC curve. The area under the curve (AUC) of the mean for Ktrans was the highest (0.826). When the cut-off of the mean for Ktrans was ≥0.47/min, its Youden index, sensitivity, and specificity were 0.625, 0.871, and 0.754, respectively. The AUC of the median of Kep was the lowest (0.772). CONCLUSION: The histogram of DCE-MRI quantitative parameters is correlated with Ki-67 expression, which has the potential to noninvasively assess the expression of Ki-67 with patients of PCa.

Measurement of labile and protein-bound heme in fixed prostate cancer cells and in cellular fractions.

Labile heme is present in the cells at very low concentrations, either unbound or loosely bound to molecules, and accessible for signaling as alarmin. Our recent work suggests that extracellular heme can be taken up and detected in the nuclei of cancer cells. Here, we describe the detailed protocol for detection of labile and total heme in prostate cancer cells and its measurement in subcellular compartments in vitro. The protocol can be adapted to be used for other cell types. For complete details on the use and execution of this protocol, please refer to Canesin et al. (2020).

Clinical significance and risk factors of International Society of Urological Pathology (ISUP) grade upgrading in prostate cancer patients undergoing robot-assisted radical prostatectomy.

BACKGROUND: The objective of this study is to investigate the clinical significance and risk factors of upgrading in the International Society of Urological Pathology (ISUP) Grade Group System in men undergoing robot-assisted radical prostatectomy (RARP) for prostate cancer. METHODS: A total of 583 patients diagnosed with prostate cancer by systematic biopsy were treated with RARP without neoadjuvant therapy from November 2011 to December 2018. Clinicopathological data were obtained from our clinical records. ISUP grade upgrading (IGU) was defined as 'ISUP grade in prostatectomy specimen determined to be higher than that in the biopsy specimen'. Clinicopathological factors, including age, PSA, prostate volume at biopsy (PV), PSA density, clinical stage, body mass index (BMI), interval from biopsy to prostatectomy, maximum percentage of cancer involvement per core (%CI), total number of biopsy cores, percentage of cancer positive biopsy cores (%PC), and sampling density were analyzed to detect potential risk factors of IGU. Biochemical recurrence (BCR) rates were calculated to analyze the effect of IGU on cancer prognosis. RESULTS: In univariate analysis, BMI was a positive predictor of IGU, while %CI, %PC, and sampling density were negative predictors of IGU. BMI and %PC were statistically significant predictors of IGU in multivariate analysis. For cases diagnosed as ISUP grade group 2 or higher at biopsy, there was a significant difference in BCR rates between cases with and without IGU. CONCLUSIONS: The results from our cohort showed that elements of both high-grade cancer risk (such as BMI) and sampling efficiency (such as %PC) contribute to IGU. Excluding cases diagnosed as ISUP grade group 1 at biopsy, BCR-free rates were significantly worse in cases with IGU, highlighting the need for more accurate pathological diagnosis at biopsy.

Is PSA density of the peripheral zone as a useful predictor for prostate cancer in patients with gray zone PSA levels?

BACKGROUND: Serum prostate-specific antigen (PSA) is widely used in screening tests for prostate cancer. As the low specificity of PSA results in unnecessary and invasive prostate biopsies, we evaluated the clinical significance of various PSAs and PSA density (PSAD) related to peripheral zones in patients with gray zone PSA level (4-10 ng/mL). METHODS: A total of 1300 patients underwent transrectal ultrasonography-guided prostate biopsy from 2014 to 2019. Among them, 545 patients in the gray zone were divided into the prostate cancer diagnosis group and the non-prostate cancer diagnosis group, and PSA, relative extra transitional zone PSA (RETzPSA), estimated post holmium laser enucleation of the prostate PSA (EPHPSA), PSAD, peripheral zone PSA density (PZPSAD) and extra-transitional zone density (ETzD) were compared and analyzed using receiver-operating characteristics (ROC) analysis after 1:1 matching using propensity score. RESULTS: Area under the ROC curve values of PSA, EPHPSA, RETzPSA, PSA density, ETzD, and PZPSAD were 0.553 (95% CI: 0.495-0.610), 0.611 (95% CI: 0.554-0.666), 0.673 (95% CI: 0.617-0.725), 0.745 (95% CI: 0.693-0.793), 0.731 (95% CI: 0.677-0.780) and 0.677 (95% CI: 0.611-0.719), respectively. PSAD had 67.11% sensitivity, 71.71% specificity, and 70.34% positive predictive rate at 0.18 ng/mL/cc. ETzD had 69.08% sensitivity, 64.47% specificity, and 66.04% positive predictive rate at 0.04 ng/mL/cc. When the cut-off value of PSAD was increased to 0.18 ng/mL/cc, the best results were obtained with an odds ratio of 5.171 (95% CI: 3.171-8.432), followed by ETzD with 4.054 (95% CI: 2.513-6.540). CONCLUSIONS: These results suggested that volume-adjusted parameters (ETzD and PSAD) might be more sensitive and accurate than various PSA in gray zone patients who required prostate biopsy to reduce unnecessary biopsy.

Cell membrane and nuclear expression of programmed death ligand-1 in prostate needle biopsy tissue in prostate cancer patients undergoing primary radiation therapy.

BACKGROUND: Programmed death ligand-1 (PD-L1) expression in cancer is often associated with cancer aggressiveness and responsiveness to treatment with PD-1 pathway inhibitors. We conducted a systematic study on the expression of membranous PD-L1 (mPD-L1) and nuclear PD-1-L1 (nPD-L1) in prostate needle biopsy specimens of prostate cancer patients who underwent primary radiotherapy and analyzed the association between PD-L1 expression and clinicopathological characteristics and prognosis of patients. METHOD: A total of 971 cancer-containing prostate needle biopsy cores from 172 patients were immunohistochemically stained with anti-PD-L1 antibody. The association of PD-L1 expression with Gleason score and tumor volume percentage was evaluated for each biopsy core. Total of 171 patients were divided according to mPD-L1 or nPD-L1 expression, and clinicopathological characteristics were compared between the positive and negative groups. The prognostic significance of mPD-L1, nPD-L1 and common prognostic factors were analyzed in terms of biochemical recurrence. RESULT: Total of 15% and 46% of biopsy cores were stained positive for mPD-L1 and nPD-L1, respectively. There was a positive correlation between Gleason score and mPD-L1 and a negative correlation between Gleason score and nPD-L1. Between mPD-L1 and nPD-L1, there was no significant correlation. There was intraindividual heterogeneity in PD-L1 expression among different Gleason scores. For mPD-L1, only pretreatment PSA was significantly higher in the positive group than in the negative, but not Gleason score and T stage. For nPD-L1, Gleason score and T stage were significantly higher in the positive group than in the negative. Both mPD-L1 and nPD-L1 expression were not predictive of BCR-free survival in univariate and multivariate analyses. CONCLUSIONS: Our results suggest that PD-1 pathway inhibitor may be a potential therapeutic option in high risk prostate cancer patients as early as neoadjuvant setting. The novel discovery of PD-L1 expression in the nucleus of PC should be subjected to further research.

The epithelial-mesenchymal transition regulators Twist, Slug, and Snail are associated with aggressive tumour features and poor outcome in prostate cancer patients.

The prognostic importance of transcription factors promoting epithelial-mesenchymal transition (EMT) and angiogenesis has not been well explored in prostate cancer patients with long follow-up, nor the interplay between these factors. The objective of this study was to assess the individual protein expression and co-expression of Twist, Slug (Snai2), Snail (Snai1), and hypoxia-inducible factor-1 alpha (Hif-1α) in prostate cancer in relation to EMT, angiogenesis, hypoxia, tumour features, disease recurrence, and patient survival. Immunohistochemical staining was performed on tissue microarray sections from 338 radical prostatectomies with long follow-up. In addition, 41 cases of prostatic hyperplasia, 33 non-skeletal metastases, 13 skeletal metastases, and 33 castration-resistant prostate carcinomas were included. Our findings were validated in external gene expression data sets. Twist was overexpressed in primary prostate cancer and markedly reduced in distant metastases (p < 0.0005). Strong expression of Twist and Slug was associated with Hif-1α in localised prostate cancer (p ≤ 0.001), and strong Twist was associated with Hif-1α in castration-resistant carcinomas (p = 0.044). Twist, Slug, and increased Snail at the tumour stromal border were associated with vascular factors (p ≤ 0.045). Each of the three EMT-regulating transcription factors were associated with aggressive tumour features and shorter time to recurrence and cancer-specific death. Notably, the co-expression of factors demonstrated an enhanced influence on outcome. In the subgroup of E-cadherinlow carcinomas, strong Slug was associated with shorter time to all end points and was an independent predictor of time to multiple end points, including cancer-specific death (hazard ratio 3.0, p = 0.041). To conclude, we demonstrate an important relation between EMT, hypoxia, and angiogenesis and a strong link between the investigated EMT regulators and aggressive tumour features and poor patient outcome in prostate cancer. Despite the retrospective nature of this long-term study, our findings could have a significant impact on the future treatment of prostate cancer, where tailored therapies might be directed simultaneously against epithelial-mesenchymal phenotypes, angiogenesis, and tumour hypoxia.

A distinct repertoire of cancer-associated fibroblasts is enriched in cribriform prostate cancer.

Outcomes for men with localized prostate cancer vary widely, with some men effectively managed without treatment on active surveillance, while other men rapidly progress to metastatic disease despite curative-intent therapies. One of the strongest prognostic indicators of outcome is grade groups based on the Gleason grading system. Gleason grade 4 prostate cancer with cribriform morphology is associated with adverse outcomes and can be utilized clinically to improve risk stratification. The underpinnings of disease aggressiveness associated with cribriform architecture are not fully understood. Most studies have focused on genetic and molecular alterations in cribriform tumor cells; however, less is known about the tumor microenvironment in cribriform prostate cancer. Cancer-associated fibroblasts (CAFs) are a heterogeneous population of fibroblasts in the tumor microenvironment that impact cancer aggressiveness. The overall goal of this study was to determine if cribriform prostate cancers are associated with a unique repertoire of CAFs. Radical prostatectomy whole-tissue sections were analyzed for the expression of fibroblast markers (ASPN in combination with FAP, THY1, ENG, NT5E, TNC, and PDGFRß) in stroma adjacent to benign glands and in Gleason grade 3, Gleason grade 4 cribriform, and Gleason grade 4 noncribriform prostate cancer by RNAscope®. Halo® Software was used to quantify percent positive stromal cells and expression per positive cell. The fibroblast subtypes enriched in prostate cancer were highly heterogeneous. Both overlapping and distinct populations of low abundant fibroblast subtypes in benign prostate stroma were enriched in Gleason grade 4 prostate cancer with cribriform morphology compared to Gleason grade 4 prostate cancer with noncribriform morphology and Gleason grade 3 prostate cancer. In addition, gene expression was distinctly altered in CAF subtypes adjacent to cribriform prostate cancer. Overall, these studies suggest that cribriform prostate cancer has a unique tumor microenvironment that may distinguish it from other Gleason grade 4 morphologies and lower Gleason grades.

Removal of optimal cutting temperature (O.C.T.) compound from embedded tissue for MALDI imaging of lipids.

Matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) is a common molecular imaging modality used to characterise the abundance and spatial distribution of lipids in situ. There are several technical challenges predominantly involving sample pre-treatment and preparation which have complicated the analysis of clinical tissues by MALDI-MSI. Firstly, the common embedding of samples in optimal cutting temperature (O.C.T.), which contains high concentrations of polyethylene glycol (PEG) polymers, causes analyte signal suppression during mass spectrometry (MS) by competing for available ions during ionisation. This suppressive effect has constrained the application of MALDI-MSI for the molecular mapping of clinical tissues. Secondly, the complexity of the mass spectra is obtained by the formation of multiple adduct ions. The process of analyte ion formation during MALDI can generate multiple m/z peaks from a single lipid species due to the presence of alkali salts in tissues, resulting in the suppression of protonated adduct formation and the generation of multiple near isobaric ions which produce overlapping spatial distributions. Presented is a method to simultaneously remove O.C.T. and endogenous salts. This approach was applied to lipid imaging in order to prevent analyte suppression, simplify data interpretation, and improve sensitivity by promoting lipid protonation and reducing the formation of alkali adducts.

Reference man for radiological protection: 71 chemical elements' content of the prostate gland (normal and cancerous).

Frequently knowledge of elemental content of human organs and tissues is required for a variety of applications. These can include brachytherapy and radiotherapy planning, radiation dosimetry and radiation protection. Revised reference values of chemical element mass fractions in normal and cancerous prostate tissues of the Reference (European Caucasian) Man are suggested as a result of this work. Autopsies of 37 apparently healthy males (mean age 55 ± 11 years, range 41-87 years) provided the prostatic tissues studied. The investigated individuals lived in a non-industrial, Central European region of Russia and had suffered sudden death. Also, tissues were studied from 62 subjects with prostate cancer (mean age 65 ± 10 years, range 40-79 years). Sixty-seven elemental mass fractions were determined in each of these 99 prostates. Analytical methods employed were inductively coupled plasma atomic emission spectrometry, neutron activation analysis with high-resolution spectrometry of short-lived and long-lived radionuclides, energy dispersive X-ray fluorescence analysis, and inductively coupled plasma mass spectrometry. Whichever method was employed, the necessary quality control measures were utilized. Results presented here include a systematic analysis of both the prostatic data presented here for 67 elements and also others' published findings, to make a total of 71 elemental mass fraction values.

Evaluating determinants of receipt of molecular imaging in biochemical recurrent prostate cancer.

BACKGROUND: Molecular imaging with novel radiotracers is changing the treatment landscape in prostate cancer (PCa). Currently, standard of care includes either conventional and molecular imaging at time of biochemical recurrence (BCR). This study evaluated the determinants of and cost associated with utilization of molecular imaging for BCR PCa. METHODS: This is a retrospective observational cohort study among men with BCR PCa from June 2018 to May 2019. Multivariate logistic regression models were employed to analyze the primary outcome: receipt of molecular imaging (e.g. Fluciclovine PET and Prostate Specific Membrane Antigen PET) as part of diagnostic work-up for BCR PCa. Multivariate linear regression models were used to analyze the secondary outcome: overall healthcare cost within a 1-year time frame. RESULTS: The study sample included 234 patients; 79.1% White, 2.1% Black, 8.5% Asian/Pacific Islander, and 10.3% Other. The majority were 55 years or older (97.9%) and publicly insured (74.8%). Analysis indicated a one-unit reduction in PSA is associated with 1.3 times higher likelihood of receiving molecular imaging (p < 0.01). Analysis found that privately insured patients were associated with approximately $500,000 more in hospital reimbursement (p < 0.01) as compared to the publicly insured. Additionally, a one-unit increase in PSA is associated with $6254 increase in hospital reimbursement or an increase in total payments by 2.1% (p < 0.05). CONCLUSIONS: Higher PSA was associated with lower likelihood for molecular imaging and higher cost in a one-year time frame. Higher cost was also associated with private insurance, but there was no clear relationship between insurance type and imaging type.

Pseudouridine as a novel biomarker in prostate cancer.

Epitranscriptomic analysis has recently led to the profiling of modified nucleosides in cancer cell biological matrices, helping to elucidate their functional roles in cancer and reigniting interest in exploring their use as potential markers of cancer development and progression. Pseudouridine, one of the most well-known and the most abundant of the RNA nucleotide modifications, is the C5-glycoside isomer of uridine and its distinctive physiochemical properties allows it to perform many essential functions. Pseudouridine functionally (a) confers rigidity to local RNA structure by enhancing RNA stacking, engaging in a cooperative effect on neighboring nucleosides that overall contributes to RNA stabilization (b) refines the structure of tRNAs, which influences their decoding activity (c) facilitates the accuracy of decoding and proofreading during translation and efficiency of peptide bond formation, thus collectively improving the fidelity of protein biosynthesis and (e) dynamically regulates mRNA coding and translation. Biochemical synthesis of pseudouridine is carried out by pseudouridine synthases. In this review we discuss the evidence supporting an association between elevated pseudouridine levels with the incidence and progression of human prostate cancer and the translational significance of the value of this modified nucleotide as a novel biomarker in prostate cancer progression to advanced disease.

Tracking the expression of therapeutic protein targets in rare cells by antibody-mediated nanoparticle labelling and magnetic sorting.

Molecular-level features of tumours can be tracked using single-cell analyses of circulating tumour cells (CTCs). However, single-cell measurements of protein expression for rare CTCs are hampered by the presence of a large number of non-target cells. Here, we show that antibody-mediated labelling of intracellular proteins in the nucleus, mitochondria and cytoplasm of human cells with magnetic nanoparticles enables analysis of target proteins at the single-cell level by sorting the cells according to their nanoparticle content in a microfluidic device with cell-capture zones sandwiched between arrays of magnets. We used the magnetic labelling and cell-sorting approach to track the expression of therapeutic protein targets in CTCs isolated from blood samples of mice with orthotopic prostate xenografts and from patients with metastatic castration-resistant prostate cancer. We also show that mutated proteins that are drug targets or markers of therapeutic response can be directly identified in CTCs, analysed at the single-cell level and used to predict how mice with drug-susceptible and drug-resistant pancreatic tumour xenografts respond to therapy.