Prostate cancer: updates on current strategies for screening, diagnosis and clinical implications of treatment modalities

Research progress on the structure, function, and use of angiogenin in malignant tumours

Angiogenin (ANG) is a specialised secreted ribonuclease, also known as RNase5, that is widely expressed in vertebrates. ANG dysregulation is closely associated with the development of breast, nasopharyngeal, and lung cancers. In recent years, studies have found that ANG not only induces neovascularisation by activating endothelial cells, but also plays a regulatory role in the plasticity of cancer cells. Cellular plasticity plays pivotal roles in cancer initiation, progression, migration, therapeutic resistance, and relapse. Therefore, it is a promising biomarker for cancer diagnosis, prognostic evaluation, and therapy. This review summarises the current knowledge regarding the roles and clinical applications of ANG in cancer development and progression.

Co-transient expression of PSA-Fc and PAP-Fc fusion protein in plant as prostate cancer vaccine candidates and immune responses in mice

KEY MESSAGE

PAP-FcK and PSA-FcK prostate cancer antigenic proteins transiently co-expressed in plant induce their specific humoral immune responses in mice. Prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) have been considered as immunotherapeutic antigens for prostate cancer. The use of a single antigenic agent is unlikely to be effective in eliciting immunotherapeutic responses due to the heterogeneous and multifocal nature of prostate cancer. Thus, multiple antigens have been combined to enhance their anti-cancer effects. In the current study, PSA and PAP were fused to the crystallizable region (Fc region) of immunoglobulin G1 and tagged with KDEL, the endoplasmic reticulum (ER) retention signal motif, to generate PSA-FcK and PAP-FcK, respectively, and were transiently co-expressed in Nicotiana benthamiana. Western blot analysis confirmed the co-expression of PSA-FcK and PAP-FcK (PSA-FcK + PAP-FcK) with a 1:3 ratios in the co-infiltrated plants. PSA-FcK, PAP-FcK, and PSA-FcK + PAP-FcK proteins were successfully purified from N. benthamiana by protein A affinity chromatography. ELISA showed that anti-PAP and anti-PSA antibodies successfully detected PAP-FcK and PSA-FcK, respectively, and both detected PSA-FcK + PAP-FcK. Surface plasmon resonance (SPR) analysis confirmed the binding affinity of the plant-derived Fc fusion proteins to FcγRI/CD64. Furthermore, we also confirmed that mice injected with PSA-FcK + PAP-FcK produced both PSA- and PAP-specific IgGs, demonstrating their immunogenicity. This study suggested that the transient plant expression system can be applied to produce the dual-antigen Fc fusion protein (PSA-FcK + PAP-FcK) for prostate cancer immunotherapy.

The Impact of Receipt of Information on Prostate-Specific Antigen Testing on Screening with the Prostate-Specific Antigen Test

There is controversy on prostate cancer screening with the prostate-specific antigen (PSA) test in the USA, and as a result, there has been an increased push for physicians to have a thorough discussion with patients on the advantages and disadvantages of prostate cancer screening with the PSA blood test. Prior studies showed that pre-screening discussions increased the likelihood of PSA testing. This study is aimed at examining the impact of discussions of the advantages and disadvantages of the PSA test among men that fit the prostate cancer screening guidelines determined by the American Urological Association (AUA). This cross-sectional study used secondary data from the 2018 Behavior Risk Factor Surveillance System (BRFSS) in the USA. The analytic sample was determined based on the American Urological Association (AUA) guidelines for prostate cancer screening (n = 54,607). Approximately, 89.5% of men underwent PSA testing. The odds of PSA testing were higher for men who received information on only the advantages of PSA testing (OR = 3.40, 95% CI = 2.80, 4.13), only the disadvantages of PSA testing (OR = 1.52, 95% CI = 1.02, 2.28), and both advantages and disadvantages of PSA testing (OR = 2.99, 95% CI = 2.46, 3.63) compared to men who received no information. Discussions with men, that meet the requirements for prostate cancer screening, about the advantages and disadvantages of PSA testing increased the likelihood that men would undergo PSA testing.

Circulating plasma miR222-3P status and its potential diagnostic performance in prostate cancer

BACKGROUND

Although studies suggest that miR222-3p is dysregulated in prostate cancer (PC) cells and tissues, the possible changes in the level of miR222-3p in the plasma samples of PC patients remained unclear. The present study aimed to evaluate the diagnostic value of the plasma miR222-3p expression level as a potential biomarker in PC, benign prostatic hyperplasia (BPH) and healthy people.

METHODS

Blood samples were collected from 100 adult males (54 patients with PC, 27 patients with BPH and 19 healthy individuals) referred to our affiliated hospital. The expression level of miR222-3p was evaluated using a quantitative reverse transcription-polymerase chain reaction. Receiver operating characteristic curves were used to evaluate miR222-3p diagnostic accuracy for discriminating between the PC, BPH and healthy individuals.

RESULTS

The expression level of miR222-3p was significantly higher in PC patients compared to healthy individuals as a fold change of 5.3 (p = 0.009), but not for BPH individuals. The diagnostic value of the plasma miR222-3p for discrimination of the PC patients from healthy individuals was reasonable [cut-off value (fold change relative to miR16-5p) = 1.69, area under the curve = 0.73, sensitivity = 0.75 and specificity = 0.74].

CONCLUSIONS

Circulating plasma miR-222-3p significantly upregulated in PC patients, but not in BPH ones. Besides these preliminary results showed that miR222-3p has the potential to discriminate PC patients from healthy ones. Addittional studies with a larger sample size are required to confirm these data.

Design and Implementation of Taizhou Integrated Prostate Screening

A community-based prostate cancer screening program was conducted to assess the morbidity and associated factors for prostate cancer among the subpopulation of men aged ≥50 years in Taizhou, China. Taizhou Integrated Prostate Screening (TIPS) is a large, observational, population-based study of prostate cancer screening data based on serum prostate-specific antigen (PSA) concentrations. A pilot census of all male residents aged 50 years or older was conducted in Luqiao District, one of the field sites of the TIPS cohort in the city of Taizhou, Zhejiang. The interviewer-administered questionnaire evaluated demographic characteristics and environmental exposure factors. A total of 1,806 out of 3,516 participants completed the questionnaire. The overall prevalence of PSA ≥4 ng/mL was 11.5%, and included participants at low risk (9.2%), moderate risk (1.7%), and high risk (0.6%). Participants aged 60-69, 70-79, and ≥80 years had a 2.7-fold, 4.2-fold, and 6.5-fold higher risk of elevated PSA, respectively, in comparison with those aged 50 to 59 years (p < .001). Eighteen patients were diagnosed with prostate cancer, of whom 11 (61.1%) underwent radical surgery. This community-based PSA screening program indicated the results for early detection of prostate cancer among men aged ≥50 years. Early screening and appropriate clinical therapy for the management of prostate cancer are essential in this subpopulation.

Comparison of Internal Dosimetry of 18 F-PSMA-1007 and 68 Ga-PSMA-11-HBED-CC

BACKGROUND

Prostate cancer (PCa) is the most common cancer in men worldwide. Targeting prostate-specific membrane antigen (PSMA) using radiopharmaceuticals has shown promising results for PCa imaging as well as theranostics. 68 Ga-based PSMA imaging is limited by production of small quantities by generator, and it has led to quest for cyclotron produced 18 F-based PSMA ligands. In the current study, we evaluated the biodistribution and internal dosimetry of 18 F-PSMA-1007 and compared it with 68 Ga-PSMA-11-HBED-CC.

MATERIALS AND METHODS

A total of 8 patients with histopathologically proven PCa were included in the study, of whom 4 patients underwent 18 F-PSMA-1007, and the other 4 patients underwent 68 Ga-PSMA-11-HBED-CC PET/CT. The biodistribution of both tracers was quantified for different organs by computing SUVs. All the patients underwent 5-point serial imaging to compute equivalent dose to essential organs and whole-body effective dose using OLINDA-based dosimetry.

RESULTS

The radiotracer uptake in brain, lacrimal gland, salivary gland, heart, lung, liver, gallbladder, spleen, pancreas, intestine, gluteal muscle, and bone marrow were found to be higher in 18 F-PSMA-1007 PET as compared with 68 Ga PSMA-11 PET. Kidney and urinary bladder showed higher SUV value on 68 Ga-PSMA-11-HBED-CC as compared with 18 F-PSMA-1007.The whole-body effective dose from 18 F-PSMA-1007 (1.46E-02 mSv/MBq) was higher than 68 Ga-PSMA-11-HBED-CC (1.03E-02 mSv/MBq). The highest mean equivalent dose from 18 F-PSMA-1007 was observed in the kidneys (1.48E-01 mGy/MBq), followed by spleen (mean, 1.06E-01 mGy/MBq) and liver (6.80E-02 mGy/MBq), whereas 68 Ga-PSMA-11-HBED-CC equivalent dose was maximum in the kidneys (2.13E-01 mGy/MBq), followed by liver (3.03E-02 mGy/MBq), spleen (2.90E-02 mGy/MBq), adrenals (2.67E-02 mGy/MBq), and urinary bladder (1.89E-02 mGy/MBq).

CONCLUSION

Whole-body effective dose from 18 F-PSMA-1007 is higher compared with 68 Ga-PSMA-11-HBED-CC. 18 F-PSMA-1007 shows lesser urinary bladder clearance compared with 68 Ga-PSMA-11-HBED-CC, which can allow better interpretation of prostatic bed without significant radioactive urine interference. 18 F-PSMA-1007 is a cyclotron-produced alternative to generator-produced 68 Ga-PSMA-11-HBED-CC and can emerge as a good diagnostic surrogate for patients planned for 177 Lu-PSMA-617 therapy.

The functional roles of the circRNA/Wnt axis in cancer

CircRNAs, covalently closed noncoding RNAs, are widely expressed in a wide range of species ranging from viruses to plants to mammals. CircRNAs were enriched in the Wnt pathway. Aberrant Wnt pathway activation is involved in the development of various types of cancers. Accumulating evidence indicates that the circRNA/Wnt axis modulates the expression of cancer-associated genes and then regulates cancer progression. Wnt pathway-related circRNA expression is obviously associated with many clinical characteristics. CircRNAs could regulate cell biological functions by interacting with the Wnt pathway. Moreover, Wnt pathway-related circRNAs are promising potential biomarkers for cancer diagnosis, prognosis evaluation, and treatment. In our review, we summarized the recent research progress on the role and clinical application of Wnt pathway-related circRNAs in tumorigenesis and progression.

Photodynamic Therapy-Adjunctive Therapy in the Treatment of Prostate Cancer

The alarming increase in the number of advanced-stage prostate cancer cases with poor prognosis has led to a search for innovative methods of treatment. In response to the need for implementation of new and innovative methods of cancer tissue therapy, we studied photodynamic action in excised prostate tissue in vitro as a model for photodynamic therapy. To ascertain the effects of photodynamic action in prostate tissue, Rose Bengal (0.01 to 0.05 mM) was used as a photosensitizer in the presence of oxygen and light to generate singlet oxygen in tissues in vitro. Five preset concentrations of Rose Bengal were chosen and injected into prostate tissue samples (60 samples with 12 replications for each RB concentration) that were subsequently exposed to 532 nm light. The effects of irradiation of the Rose Bengal infused tissue samples were determined by histopathological analysis. Histopathological examination of prostate samples subjected to photodynamic action revealed numerous changes in the morphology of the neoplastic cells and the surrounding tissues. We conclude that the morphological changes observed in the prostate cancer tissues were a result of the photogeneration of cytotoxic singlet oxygen. The tissue damage observed post photodynamic action offers an incentive for continued in vitro investigations and future in vivo clinical trials.

Nano-Theranostics for the Sensing, Imaging and Therapy of Prostate Cancers

We highlight hereby recent developments in the emerging field of theranostics, which encompasses the combination of therapeutics and diagnostics in a single entity aimed for an early-stage diagnosis, image-guided therapy as well as evaluation of therapeutic outcomes of relevance to prostate cancer (PCa). Prostate cancer is one of the most common malignancies in men and a frequent cause of male cancer death. As such, this overview is concerned with recent developments in imaging and sensing of relevance to prostate cancer diagnosis and therapeutic monitoring. A major advantage for the effective treatment of PCa is an early diagnosis that would provide information for an appropriate treatment. Several imaging techniques are being developed to diagnose and monitor different stages of cancer in general, and patient stratification is particularly relevant for PCa. Hybrid imaging techniques applicable for diagnosis combine complementary structural and morphological information to enhance resolution and sensitivity of imaging. The focus of this review is to sum up some of the most recent advances in the nanotechnological approaches to the sensing and treatment of prostate cancer (PCa). Targeted imaging using nanoparticles, radiotracers and biomarkers could result to a more specialised and personalised diagnosis and treatment of PCa. A myriad of reports has been published literature proposing methods to detect and treat PCa using nanoparticles but the number of techniques approved for clinical use is relatively small. Another facet of this report is on reviewing aspects of the role of functional nanoparticles in multimodality imaging therapy considering recent developments in simultaneous PET-MRI (Positron Emission Tomography-Magnetic Resonance Imaging) coupled with optical imaging in vitro and in vivo, whilst highlighting feasible case studies that hold promise for the next generation of dual modality medical imaging of PCa. It is envisaged that progress in the field of imaging and sensing domains, taken together, could benefit from the biomedical implementation of new synthetic platforms such as metal complexes and functional materials supported on organic molecular species, which can be conjugated to targeting biomolecules and encompass adaptable and versatile molecular architectures. Furthermore, we include hereby an overview of aspects of biosensing methods aimed to tackle PCa: prostate biomarkers such as Prostate Specific Antigen (PSA) have been incorporated into synthetic platforms and explored in the context of sensing and imaging applications in preclinical investigations for the early detection of PCa. Finally, some of the societal concerns around nanotechnology being used for the detection of PCa are considered and addressed together with the concerns about the toxicity of nanoparticles–these were aspects of recent lively debates that currently hamper the clinical advancements of nano-theranostics. The publications survey conducted for this review includes, to the best of our knowledge, some of the most recent relevant literature examples from the state-of-the-art. Highlighting these advances would be of interest to the biomedical research community aiming to advance the application of theranostics particularly in PCa diagnosis and treatment, but also to those interested in the development of new probes and methodologies for the simultaneous imaging and therapy monitoring employed for PCa targeting.

MRI Based Radiomics Compared With the PI-RADS V2.1 in the Prediction of Clinically Significant Prostate Cancer: Biparametric vs Multiparametric MRI

Purpose

To compare the performance of radiomics to that of the Prostate Imaging Reporting and Data System (PI-RADS) v2.1 scoring system in the detection of clinically significant prostate cancer (csPCa) based on biparametric magnetic resonance imaging (bpMRI) vs. multiparametric MRI (mpMRI).

Methods

A total of 204 patients with pathological results were enrolled between January 2018 and December 2019, with 142 patients in the training cohort and 62 patients in the testing cohort. The radiomics model was compared with the PI-RADS v2.1 for the diagnosis of csPCa based on bpMRI and mpMRI by using receiver operating characteristic (ROC) curve analysis.

Results

The radiomics model based on bpMRI and mpMRI signatures showed high predictive efficiency but with no significant differences (AUC = 0.975 vs 0.981, p=0.687 in the training cohort, and 0.953 vs 0.968, p=0.287 in the testing cohort, respectively). In addition, the radiomics model outperformed the PI-RADS v2.1 in the diagnosis of csPCa regardless of whether bpMRI (AUC = 0.975 vs. 0.871, p= 0.030 for the training cohort and AUC = 0.953 vs. 0.853, P = 0.024 for the testing cohort) or mpMRI (AUC = 0.981 vs. 0.880, p= 0.030 for the training cohort and AUC = 0.968 vs. 0.863, P = 0.016 for the testing cohort) was incorporated.

Conclusions

Our study suggests the performance of bpMRI- and mpMRI-based radiomics models show no significant difference, which indicates that omitting DCE imaging in radiomics can simplify the process of analysis. Adding radiomics to PI-RADS v2.1 may improve the performance to predict csPCa.

Prostate Cancer Presenting With an Unusual Presentation of Rectal Pain and Bleeding

We report an atypical case of prostate cancer with rectal involvement presenting with gastrointestinal symptoms predominately and a rectal mass. A 51-year-old male patient came to the hospital with abdominal pain and rectal bleeding. Imaging revealed prostate enlargement, perirectal lymphadenopathy, and multiple hepatic and pulmonary nodules. The patient also had an elevated prostate-specific antigen (PSA) of 502 ng/mL (against normal range 0.6-0.7 ng/mL). Biopsies were performed on tissue samples taken from the rectum and prostate gland, which confirmed the diagnosis of prostate adenocarcinoma. The lack of urinary symptoms and close clinical similarity to colorectal cancer presented a diagnostic challenge for us. Familiarity with this specific presentation of prostate cancer is necessary to avoid misdiagnoses and guide correct treatment.

Urolithins: The Gut Based Polyphenol Metabolites of Ellagitannins in Cancer Prevention, a Review

Cancer as a disease continues to ravage the world population without regard to sex, age, and race. Due to the growing number of cases worldwide, cancer exerts a significant negative impact on global health and the economy. Interestingly, chemotherapy has been used over the years as a therapeutic intervention against cancer. However, high cost, resistance, and toxic by-effects to treatment have overshadowed some of its benefits. In recent times, efforts have been ongoing in searching for anticancer therapeutics of plant origin, focusing on polyphenols. Urolithins are secondary polyphenol metabolites derived from the gut microbial action on ellagitannins and ellagic acid-rich foods such as pomegranate, berries, and nuts. Urolithins are emerging as a new class of anticancer compounds that can mediate their cancer-preventive activities through cell cycle arrest, aromatase inhibition, induction of apoptosis, tumor suppression, promotion of autophagy, and senescence, transcriptional regulation of oncogenes, and growth factor receptors. In this review, we discussed the growing shreds of evidence supporting these secondary phenolic metabolites' anticancer properties. Furthermore, we have pointed out some of the future directions needed to establish urolithins as anticancer agents.

Elevated Expression of Glycerol-3-Phosphate Phosphatase as a Biomarker of Poor Prognosis and Aggressive Prostate Cancer

The limitations of the biomarker prostate-specific antigen (PSA) necessitate the pursuit of biomarkers capable of better identifying high-risk prostate cancer (PC) patients in order to improve their therapeutic management and outcomes. Aggressive prostate tumors characteristically exhibit high rates of glycolysis and lipogenesis. Glycerol 3-phosphate phosphatase (G3PP), also known as phosphoglycolate phosphatase (PGP), is a recently identified mammalian enzyme, shown to play a role in the regulation of glucose metabolism, lipogenesis, lipolysis, and cellular nutrient-excess detoxification. We hypothesized that G3PP may relieve metabolic stress in cancer cells and assessed the association of its expression with PC patient prognosis. Using immunohistochemical staining, we assessed the epithelial expression of G3PP in two different radical prostatectomy (RP) cohorts with a total of 1797 patients, for whom information on biochemical recurrence (BCR), metastasis, and mortality was available. The association between biomarker expression, biochemical recurrence (BCR), bone metastasis, and prostate cancer-specific survival was established using log-rank and multivariable Cox regression analyses. High expression of G3PP in PC epithelial cells is associated with an increased risk of BCR, bone metastasis, and PC-specific mortality. Multivariate analysis revealed high G3PP expression in tumors as an independent predictor of BCR and bone metastasis development. High G3PP expression in tumors from patients eligible for prostatectomies is a new and independent prognostic biomarker of poor prognosis and aggressive PC for recurrence, bone metastasis, and mortality.

Use of Radiomics to Improve Diagnostic Performance of PI-RADS v2.1 in Prostate Cancer

Objective

To investigate whether a radiomics model can help to improve the performance of PI-RADS v2.1 in prostate cancer (PCa).

Methods

This was a retrospective analysis of 203 patients with pathologically confirmed PCa or non-PCa between March 2015 and December 2016. Patients were divided into a training set (n = 141) and a validation set (n = 62). The radiomics model (Rad-score) was developed based on multi-parametric MRI including T2 weighted imaging (T2WI), diffusion weighted imaging (DWI), apparent diffusion coefficient (ADC) imaging, and dynamic contrast enhanced (DCE) imaging. The combined model involving Rad-score and PI-RADS was compared with PI-RADS for the diagnosis of PCa by using the receiver operating characteristic curve (ROC) analysis.

Results

A total of 112 (55.2%) patients had PCa, and 91 (44.8%) patients had benign lesions. For PCa versus non-PCa, the Rad-score had a significantly higher area under the ROC curve (AUC) [0.979 (95% CI, 0.940–0.996)] than PI-RADS [0.905 (0.844–0.948), P = 0.002] in the training set. However, the AUC between them was insignificant in the validation set [0.861 (0.749–0.936) vs. 0.845 (0.731–0.924), P = 0.825]. When Rad-score was added to PI-RADS, the performance of the PI-RADS was significantly improved for the PCa diagnosis (AUC = 0.989, P < 0.001 for the training set and AUC = 0.931, P = 0.038 for the validation set).

Conclusions

The radiomics based on multi-parametric MRI can help to improve the diagnostic performance of PI-RADS v2.1 in PCa.

Precision Medicine Approach in Prostate Cancer

Prostate cancer is the most prevalent type of cancer and the second cause of death in men worldwide. Various diagnostic and treatment procedures are available for this type of malignancy, but High-grade or locally advanced prostate cancers showed the potential to develop to lethal phase that can be causing dead. Therefore, new approaches are needed to prolong patients' survival and to improve their quality of life. Precision medicine is a novel emerging field that plays an essential role in identifying new sub-classifications of diseases and in providing guidance in treatment that is based on individual multi-omics data. Multi-omics approaches include the use of genomics, transcriptomics, proteomics, metabolomics, epigenomics and phenomics data to unravel the complexity of a disease-associated biological network, to predict prognostic biomarkers, and to identify new targeted drugs for individual cancer patients. We review the impact of multi-omics data in the framework of systems biology in the era of precision medicine, emphasising the combination of molecular imaging modalities with highthroughput techniques and the new treatments that target metabolic pathways involved in prostate cancer.

Circular RNAs as biomarkers and therapeutic targets in cancer

Circular RNAs (circRNAs) are a class of single-stranded closed non-coding RNA molecules (ncRNAs), which are formed as a result of reverse splicing of mRNAs. Despite their relative abundance, an interest in understanding their regulatory importance is rather recent. High stability, abundance and evolutionary conservation among species underline some of their important traits. CircRNAs perform a variety of cellular functions ranging from miRNA and proteins sponges to transcriptional modulation and splicing. Additionally, most circRNAs are expressed aberrantly in pathological conditions suggesting their possible exploitation as diagnostic biomarkers. Their covalent closed cyclic structure resulting in resistance to RNases further makes them suitable as cancer biomarkers. Studies involving human tumors have verified differences in the expression profiles of circRNAs, indicating a regulatory role in cancer pathogenesis and metastasis. As endogenous competitive RNA, circRNAs can regulate tumor proliferation and invasion. Further, some circRNAs located in the nucleus can regulate transcription of genes by binding to RNA polymerase II. In this review, we elaborate the characteristics, functions and mechanisms of action of circRNAs in cancer. We also discuss the possibility of using circRNAs as potential therapeutic targets and biomarkers for cancer.

Super-enhancer in prostate cancer: transcriptional disorders and therapeutic targets

Abnormal activity of oncogenic and tumor-suppressor signaling pathways contributes to cancer and cancer risk in humans. Transcriptional dysregulation of these pathways is commonly associated with tumorigenesis and the development of cancer. Genetic and epigenetic alterations may mediate dysregulated transcriptional activity. One of the most important epigenetic alternations is the non-coding regulatory element, which includes both enhancers and super-enhancers (SEs). SEs, characterized as large clusters of enhancers with aberrant high levels of transcription factor binding, have been considered as key drivers of gene expression in controlling and maintaining cancer cell identity. In cancer cells, oncogenes acquire SEs and the cancer phenotype relies on these abnormal transcription programs driven by SEs, which leads to cancer cells often becoming addicted to the SEs-related transcription programs, including prostate cancer. Here, we summarize recent findings of SEs and SEs-related gene regulation in prostate cancer and review the potential pharmacological inhibitors in basic research and clinical trials.

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.

Association study between common variations in some candidate genes and prostate adenocarcinoma predisposition through multi-stage approach in Iranian population

BACKGROUND

Prostate cancer is one of the five common cancers and has the second incidence rate and the third mortality rate in Iranian population. The purpose of this study was to evaluate the association of rs16901979, rs4242382 and rs1447295 on 8q24 locus, rs2735839 (KLK3 gene) and rs721048 (EHBP1 gene) with prostate adenocarcinoma through multi-stage approach to identify the polymorphisms associated with prostate cancer and use them as screening factors. Screening tests can identify people who may have a chance of developing the disease before detection and any symptoms.

METHODS

The case-control study included 103 cases (prostate adenocarcinoma) and 100 controls (benign prostatic hyperplasia). Tetra-primer ARMS-PCR was used to genotyping of each participant. A Multi-stage approach was used for efficient genomic study. In this method, a smaller number of people can be used. Chi-squared, Fisher's exact test and logistic regression were used to investigate the SNPs associated with prostate cancer and Gleason score.

RESULTS

In the first stage (59 men), the frequency of polymorphisms rs16901979, rs4242382, rs1447295, rs2735839 and rs721048 in the prostate adenocarcinoma group was evaluated compared to the control group (P-value < 0.3) in order to select meaningful polymorphisms. There was not any significant difference between genotype frequency rs16901979 (P = 0.671) and rs721048 (P = 0.474) in the case group compared to BPH. Therefore, these polymorphisms were eliminated, and in the second step (144 men), rs4242382, rs2735839 and rs1447295 were evaluated (P-value < 0.05). According to the total population (203 men), there was significant difference between genotype frequency rs4242382 (P = 0.001), rs2735839 (P = 0.000) and rs1447295 (P = 0.005) even after using Bonferroni correction (p = 0.016). The effect of these three polymorphisms on prostate cancer was not modified by age and PSA. There was a significant difference between the allelic frequency of A vs G (rs4242382, rs2735839) at all classes of Gleason score and A vs C (rs1447295) at Gleason score ≥ 8.

CONCLUSIONS

The results of this study for rs2735839, rs4242382 and rs1447295 indicate the association of these polymorphisms with prostate adenocarcinoma predisposition in Iranian population. Exposure effect is homogeneous between different ages and PSA level categories. These three polymorphisms should be studied in a larger population to confirm these results.

The role of noncoding RNAs and sirtuins in cancer drug resistance

Cancer is a rising and major health issue around the world. The acquisition of resistance to chemotherapeutic drugs is a great obstacle for the effective treatment of nearly all cancers. Drug resistance is regulated by multiple factors and mechanisms including genetic mutations, abnormal expression of some cellular transporters such as multidrug resistance (MDR) transporters, changes in apoptotic pathways, cancer stem cells, tumor microenvironment, and noncoding RNAs (ncRNAs). Evidence clearly indicates a key role for sirtuins in several characteristics of cancer drug resistance. Recent studies demonstrated the crucial impact of some ncRNAs on sirtuins expression leading to modulation of chemotherapy resistance in cancers. In this review, we will focus on the current findings about the impacts of ncRNAs on the sirtuins pathway and their role in drug resistance of cancer.

Long Noncoding RNA SNHG1 Contributes to the Promotion of Prostate Cancer Cells Through Regulating miR-377-3p/AKT2 Axis

Background: Long noncoding RNAs could serve as a candidate target for prostate cancer (PCa) diagnosis and treatment. The current study aimed to investigate the role and functions of SNHG1 in PCa cells. Materials and Methods: Abnormal expression of SNHG1, survival analysis, and target gene were determined or predicted by bioinformatics techniques. Gene expressions at transcriptional and translational levels were determined by Quantitative Real-time PCR and Western blotting, respectively. Cell viability, growth, and apoptosis rate were detected by Cell Counting Kit-8, colony formation assay and flow cytometry. Results: The results showed that SNHG1 was highly expressed in PCa tissues, which was accompanied by decreased miR-377-3p expression and poor overall survival rate, and that miR-377-3p was predicted as the target of SNHG1 in PCa cells. Moreover, SNHG1 counteracted the effects of miR-377-3p on inhibiting cell growth and promoting apoptosis of PCa cells. Furthermore, miR-377-3p counteracted the effects of AKT2 on promoting cell viability, growth, and suppressing apoptosis of PCa cells. In addition, AKT2 expression was proved to be regulated by miR-377-3p. Conclusions: The SNHG1/miR-377-3p/AKT2 regulatory axis in PCa cells was disclosed. The upregulated AKT2 might be a result of dysregulated interaction balance between the expressions of miR-377-3p and SNHG1. Based on such discoveries, the intervention of SNHG1/miR-377-3p/AKT2 axis could be further explored in the treatment of PCa.

Prostate Cancer Epithelial Mesenchymal Transition by TGF-β1 exposure monitored with a Photonic Crystal Biosensor

During prostate cancer progression, cancerous epithelial cells can undergo epithelial-mesenchymal transition (EMT). EMT is a crucial mechanism for the invasion and metastasis of epithelial tumors characterized by the loss of cell-cell adhesion and increased cell mobility. It is associated with biochemical changes such as epithelial cell markers E-cadherin and occludins being down-regulated, and mesenchymal markers vimentin and N-cadherin being upregulated. These changes in protein expression, specifically in the cell membrane, may be monitored via biophysical principles, such as changes in the refractive index (RI) of the cell membrane. In our previous research, we demonstrated the feasibility of using cellular RI as a unique contrast parameter to accomplish label-free detection of prostate cancer cells. In this paper, we report the use of our Photonic-Crystal biosensor in a Total-Internal-Reflection (PC-TIR) configuration to construct a label-free biosensing system, which allows for ultra-sensitive quantification of the changes in cellular RI due to EMT. We induced prostate cancer cells to undergo EMT by exposing these cells to soluble Transforming Growth Factor Beta 1 (TGF-β1). The biophysical characteristics of the cellular RI were quantified extensively in comparison to non-induced cancer cells. Our study shows promising clinical potential in utilizing the PC-TIR biosensing system not only to detect prostate cancer cells, but also to evaluate changes in prostate cancer cells due to EMT.

The Multiple Roles and Therapeutic Potential of Molecular Chaperones in Prostate Cancer

Prostate cancer (PCa) is one of the most common cancer types in men worldwide. Heat shock proteins (HSPs) are molecular chaperones that are widely implicated in the pathogenesis, diagnosis, prognosis, and treatment of many cancers. The role of HSPs in PCa is complex and their expression has been linked to the progression and aggressiveness of the tumor. Prominent chaperones, including HSP90 and HSP70, are involved in the folding and trafficking of critical cancer-related proteins. Other members of HSPs, including HSP27 and HSP60, have been considered as promising biomarkers, similar to prostate-specific membrane antigen (PSMA), for PCa screening in order to evaluate and monitor the progression or recurrence of the disease. Moreover, expression level of chaperones like clusterin has been shown to correlate directly with the prostate tumor grade. Hence, targeting HSPs in PCa has been suggested as a promising strategy for cancer therapy. In the current review, we discuss the functions as well as the role of HSPs in PCa progression and further evaluate the approach of inhibiting HSPs as a cancer treatment strategy.

Identification of key genes in prostate cancer gene expression profile by bioinformatics

The aim of this study was to identify key candidate genes in prostate cancer. The gene expression profiles of GSE32448, GSE45016, GSE46602 and GSE104749 were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) between prostate cancer and normal samples were identified by R language. The gene ontology functional and pathway enrichment analyses of DEGs were performed by the Database for Annotation, Visualization and Integrated Discovery software followed by the construction of protein-protein interaction network. Hub gene identification was performed by the plug-in cytoHubba in Cytoscape software. The 217 DEGs were significantly enriched in biological processes including epithelial cell differentiation, response to estradiol and several pathways, mainly associated with protein digestion and absorption pathway in prostate cancer. Epithelial cell adhesion molecule, twist family basic helix-loop-helix transcription factor 1, CD38 molecule and vascular endothelial growth factor A were identified as hub genes. The expression levels of hub genes were consistent with data obtained in The Cancer Genome Atlas for prostate adenocarcinoma. These hub genes may be used as potential targets for prostate cancer diagnosis and treatment.