Genomic Rearrangements of PTEN in Prostate Cancer

Therapeutic Prospects of Abemaciclib for Patients with Endometrial Cancer

Endometrial cancer (EC) is a common gynecologic malignancy with a rising incidence due to obesity, comorbid conditions, and related lifestyle factors. The standard of care for primary disease consists of surgical resection with/without chemotherapy ± radiotherapy for select patients. Recurrence is common in patients with advanced-stage disease and/or high-risk features, who primarily are treated with systemic therapy. The identification of novel targets in malignant EC has led to the development of wide-range inhibitors. Abemaciclib is an orally active unique cyclin-dependent kinase (CDK) inhibitor, selective for the CDK4 and CDK6 cell cycle pathways. This agent has potential anti-neoplastic activity and is indicated in combination with various therapies such as endocrine therapy, aromatase inhibitors, and hormone therapies, primarily in breast cancer (BC). Herein, we sought to summarize the biochemical/pharmacological properties of abemaciclib and its therapeutic potential in EC. While the therapeutic role(s) of abemaciclib was fairly established in a subset of patients with advanced/metastatic BC through the pivotal MONARCH trials, its attributes and clinical utility in EC are limited. Thus, based on some promising pre-clinical/translational insights and a recent phase II study, we highlight abemaciclib's properties and potential clinical usefulness in patients with EC, particularly in recurrent estrogen-receptor-positive cases.

A Comprehensive Review and Androgen Deprivation Therapy and Its Impact on Alzheimer's Disease Risk in Older Men with Prostate Cancer

Prostate cancer (PCa) is one of the most prevalent malignancies affecting males worldwide. Despite reductions in mortality rates due to advances in early identification and treatment methods, PCa remains a major health concern. Recent research has shed light on a possible link between PCa and Alzheimer's disease (AD), which is a significant neurological ailment that affects older males all over the world. Androgen deprivation therapy (ADT), a cornerstone therapeutic method used in conjunction with radiation and palliative care in advanced metastatic PCa cases, is critical for disease management. Evidence reveals a relationship between ADT and cognitive impairment. Hormonal manipulation may cause long-term cognitive problems through processes such as amyloid beta (Aβ) aggregation and neurofibrillary tangles (NFTs). Fluctuations in basal androgen levels can upset the delicate balance of genes that are sensitive to androgen levels, contributing to cognitive impairment. This detailed review dives into the various aspects of PCa aetiology and its relationship with cognitive decline. It investigates the discovery of particular biomarkers, as well as microRNAs (miRNAs), which play important roles in pathogenic progression. The review attempts to identify potential biomarkers associated with ADT-induced cerebral changes, including Aβ oligomer buildup, NFT formation, and tauopathy, which can contribute to early-onset dementia and cognitive impairment. Besides it further aims to provide insights into innovative diagnostic and therapeutic avenues for alleviating PCa and ADT-related cognitive sequelae by unravelling these complicated pathways and molecular mechanisms.

Unveiling the Anticancer Potential of Pasak Bumi (Eurycoma Longifolia Jack) Root Extract in Prostate Cancer Treatment

Background

Prostate cancer remains a significant global health concern, necessitating the exploration of novel therapeutic avenues to enhance treatment efficacy and mitigate adverse effects. Objective This study delves into the potential anticancer properties of Pasak Bumi (Eurycoma longifolia Jack) root extract, a traditional Southeast Asian medicinal plant, against prostate cancer.

Methods

The research employs a multifaceted approach, encompassing molecular and cellular analyses to unravel the intricate mechanisms underlying Pasak Bumi's effects on prostate cancer cells. Primary focus is given to the PTEN/P13k/Akt pathway, a critical regulator of cell survival and apoptosis. Various concentrations of Pasak Bumi root extract are applied to prostate cancer cell lines, and the impact on apoptosis, cell proliferation, and key molecular targets is assessed.

Results

Preliminary findings reveal that Pasak Bumi root extract induces apoptosis in prostate cancer cells, evidenced by downstream molecular events associated with programmed cell death. The extract demonstrates concentration-dependent effects, with higher concentrations exhibiting more pronounced anticancer activity. Moreover, Pasak Bumi root extract appears to modulate the PTEN/P13k/Akt pathway, providing a potential mechanistic link to its anticancer effects. Discussion: The study's significance lies in its contribution to the evolving landscape of natural compounds as anticancer agents, particularly in the context of prostate cancer. Pasak Bumi's traditional use as a medicinal plant, coupled with emerging scientific evidence, underscores its potential translational value. The observed modulation of the PTEN/P13k/Akt pathway aligns with the current understanding of prostate cancer pathogenesis, offering a plausible explanation for Pasak Bumi's anticancer effects.

Conclusion

This research sheds light on the promising anticancer potential of Pasak Bumi root extract against prostate cancer. Further exploration of its molecular interactions, synergy with conventional therapies, and efficacy at different stages of cancer progression is warranted. The findings present Pasak Bumi as a nature-inspired candidate for prostate cancer treatment, warranting continued investigation into its therapeutic applications. As the scientific community endeavors to enhance cancer treatment modalities, Pasak Bumi emerges as a captivating subject in the pursuit of effective and minimally invasive prostate cancer therapies.

The role of NFATc1 in the progression and metastasis of prostate cancer: A review on the molecular mechanisms and signaling pathways

A common type of cancer among men is the prostate cancer that kills many people every year. The multistage of this disease and the involvement of the vital organs of the body have reduced the life span and quality of life of the people involved and turned the treatment process into a complex one. NFATc1 biomarker contributes significantly in the diagnosis and treatment of this disease by increasing its expression in prostate cancer and helping the proliferation, differentiation, and invasion of cancer cells through different signaling pathways. NFATc1 is also able to target the metabolism of cancer cells by inserting specific oncogene molecules such as c-myc that it causes cell growth and proliferation. Bone is a common tissue where prostate cancer cells metastasize. In this regard, the activity of NFATc1, through the regulation of different signaling cascades, including the RANKL/RANK signaling pathway, in turn, increases the activity of osteoclasts, and as a result, bone tissue is gradually ruined. Using Silibinin as a medicinal plant extract can inhibit the activity of osteoclasts related to prostate cancer by targeting NFATc. Undoubtedly, NFATc1 is one of the effective oncogenes related to prostate cancer, which has the potential to put this cancer on the path of progression and metastasis. In this review, we will highlight the role of NFATc1 in the progression and metastasis of prostate cancer. Furthermore, we will summarize signaling pathways and molecular mechanism, through which NFATc1 regulates the process of prostate cancer.

Overview of miR-106a Regulatory Roles: from Cancer to Aging

MicroRNAs (miRNAs) comprise a class of non-coding RNA with extensive regulatory functions within cells. MiR-106a is recognized for its super-regulatory roles in vital processes. Hence, the analysis of its expression in association with diseases has attracted considerable attention for molecular diagnosis and drug development. Numerous studies have investigated miR-106 target genes and shown that this miRNA regulates the expression of some critical cell cycle and apoptosis factors, suggesting miR-106a as an ideal diagnostic and prognostic biomarker with therapeutic potential. Furthermore, the reported correlation between miR-106a expression level and cancer drug resistance has demonstrated the complexity of its functions within different tissues. In this study, we have conducted a comprehensive review on the expression levels of miR-106a in various cancers and other diseases, emphasizing its target genes. The promising findings surrounding miR-106a suggest its potential as a valuable biomolecule. However, further validation assessments and overcoming existing limitations are crucial steps before its clinical implementation can be realized.

Unlocking the mystery associated with infertility and prostate cancer: an update

Male-specific reproductive disorders and cancers have increased intensely in recent years, making them a significant public health problem. Prostate cancer (PC) is the most often diagnosed cancer in men and is one of the leading causes of cancer-related mortality. Both genetic and epigenetic modifications contribute to the development and progression of PC, even though the exact underlying processes causing this disease have yet to be identified. Male infertility is also a complex and poorly understood phenomenon believed to afflict a significant portion of the male population. Chromosomal abnormalities, compromised DNA repair systems, and Y chromosome alterations are just a few of the proposed explanations. It is becoming widely accepted that infertility shares a link with PC. Much of the link between infertility and PC is probably attributable to common genetic defects. This article provides an overview of PC and spermatogenic abnormalities. This study also investigates the link between male infertility and PC and uncovers the underlying reasons, risk factors, and biological mechanisms contributing to this association.

The Promising Therapeutic and Preventive Properties of Anthocyanidins/Anthocyanins on Prostate Cancer

As water-soluble flavonoid derivatives, anthocyanidins and anthocyanins are the plants pigments mostly rich in berries, pomegranate, grapes, and dark color fruits. Many bioactivity properties of these advantageous phytochemicals have been reported; among them, their significant abilities in the suppression of tumor cells are of the promising therapeutic features, which have recently attracted great attention. The prostate malignancy, is considered the 2nd fatal and the most distributed cancer type in men worldwide. The present study was designated to gather the preclinical and clinical studies evaluating potencies of anthocyanidins/anthocyanins for the treatment and prevention of this cancer type for the first time. In general, findings confirm that the anthocyanins (especifically cyanidin-3-O-glucoside) indicated higher activity against prostatic neoplasms compared to their correlated anthocyanidins (e.g., delphinidin); in which potent anti-inflammatory, apoptosis, and anti-proliferative activities were analyzed. Complementary anti-prostate cancer assessment of diverse naturally occurred anthocyanidins/anthocyanins and their synthetically optimized derivatives through preclinical experiments and eventually confirmed by clinical trials can promisingly lead to discover natural-based chemotherapeutic drug options.

Targeting Protein Kinases and Epigenetic Control as Combinatorial Therapy Options for Advanced Prostate Cancer Treatment

Prostate cancer (PC), the fifth leading cause of cancer-related mortality worldwide, is known as metastatic bone cancer when it spreads to the bone. Although there is still no effective treatment for advanced/metastatic PC, awareness of the molecular events that contribute to PC progression has opened up opportunities and raised hopes for the development of new treatment strategies. Androgen deprivation and androgen-receptor-targeting therapies are two gold standard treatments for metastatic PC. However, acquired resistance to these treatments is a crucial challenge. Due to the role of protein kinases (PKs) in the growth, proliferation, and metastases of prostatic tumors, combinatorial therapy by PK inhibitors may help pave the way for metastatic PC treatment. Additionally, PC is known to have epigenetic involvement. Thus, understanding epigenetic pathways can help adopt another combinatorial treatment strategy. In this study, we reviewed the PKs that promote PC to advanced stages. We also summarized some PK inhibitors that may be used to treat advanced PC and we discussed the importance of epigenetic control in this cancer. We hope the information presented in this article will contribute to finding an effective treatment for the management of advanced PC.

Use of RNA-Seq and a Transgenic Mouse Model to Identify Genes Which May Contribute to Mutant p53-Driven Prostate Cancer Initiation

Simple Summary

We use RNA-seq analysis to identify genes that may contribute to mutant p53-mediated prostate cancer initiation in a genetically engineered mouse model (B6.129S4-Trp53tm3.1Tyj/J). A total of 1378 differentially expressed genes, including wildtype p53 target genes (e.g. Cdkn1a, Bax, Bcl2, Kras, Mdm2), p53 gain-of-function-related genes (Mgmt, Id4), and prostate cancer-related genes (Cav-1, Raf1, Kras), were identified. Mice that were homozygous or heterozygous for the Trp53 R270H mutation developed grade one PIN lesions at 3 months and 5 months, respectively, whereas wildtype mice did not develop PIN. Immunohistochemical analysis revealed decreased levels of irradiation-mediated apoptosis in homozygous and heterozygous mice when compared to wildtype counterparts, and this aligned with observed differences in apoptosis-related gene expression.

Abstract

We previously demonstrated that the Trp53-R270H mutation can drive prostate cancer (CaP) initiation using the FVB.129S4 (Trp53^tm3Tyj/wt); FVB.129S (Nkx3-1^{tm3(cre)Mmswt}) genetically engineered mouse model (GEM). We now validate this finding in a different model (B6.129S4-Trp53^tm3.1Tyj/J mice) and use RNA-sequencing (RNA-Seq) to identify genes which may contribute to Trp53 R270H-mediated prostate carcinogenesis. Wildtype (Trp53^WT/WT), heterozygous (Trp53^R270H/WT), and homozygous mice (Trp53^R270H/R270H) were exposed to 5 Gy irradiation to activate and stabilize p53, and thereby enhance our ability to identify differences in transcriptional activity between the three groups of mice. Mouse prostates were harvested 6 h post-irradiation and processed for histological/immunohistochemistry (IHC) analysis or were snap-frozen for RNA extraction and transcriptome profiling. IHC analyses determined that presence of the Trp53-R270H mutation impacts apoptosis (lower caspase 3 activity) but not cell proliferation (Ki67). RNA-Seq analysis identified 1378 differentially expressed genes, including wildtype p53 target genes (E.g., Cdkn1a, Bax, Bcl2, Kras, Mdm2), p53 gain-of-function (GOF)-related genes (Mgmt, Id4), and CaP-related genes (Cav-1, Raf1, Kras). Further understanding the mechanisms which contribute to prostate carcinogenesis could allow for the development of improved preventive methods, diagnostics, and treatments for CaP.

Aqueous metabolome of tissue-specific conditional Pten-knockout mouse prostate cancer and TRAMP neuroendocrine carcinoma

BACKGROUND

Metabolic reprograming is now a recognized hallmark of cancer. The prostate-specific phosphatase and tensin homolog deleted on chromosome 10 (Pten) gene-conditional knockout (KO) mouse carcinogenesis model is highly desirable for studying prostate cancer biology and prevention due to its close resemblance of primary molecular defects and histopathological features of human prostate cancer. We have recently published macromolecular profiling of this model by proteomics and transcriptomics, denoting a preeminence of inflammation and myeloid suppressive immune cell features. Here, we performed metabolomic analyses of Pten-KO prostate versus wild type (WT) counterpart for discernable changes in the aqueous metabolites and contrasted to those in the TRAMP neuroendocrine carcinoma (NECa).

METHODS

Three matched pairs of tissue-specific conditional Pten-KO mouse prostate and WT prostate of litter/cage-mates at 20-22 weeks of age and three pairs of TRAMP NECa versus WT (28-31 weeks) were profiled for their global aqueous metabolite changes, using hydrophilic interaction liquid chromatography-tandem mass spectrometry.

RESULTS

The Pten-KO prostate increased purine nucleotide pools, cystathionine, and both reduced and oxidized glutathione (GSH, GSSG), and gluconate/glucuronate species in addition to cholesteryl sulfate and polyamine precursor ornithine. On the contrary, Pten-KO prostate contained diminished pools of glycolytic intermediates and phosphorylcholine derivatives, select amino acids, and their metabolites. Bioinformatic integration revealed a significant shunting of glucose away from glycolysis-citrate cycle and glycerol-lipid genesis to pentose phosphate cycle for NADPH/GSH/GSSG redox and pentose moieties for purine and pyrimidine nucleotides, and glycosylation/glucuronidation. Implicit arginine catabolism to ornithine was consistent with immunosuppression in Pten-KO model. While also increased in cystathionine-GSH/GSSG, purine, and pyrimidine nucleotide pools and glucuronidation at the expense of glycolysis-citrate cycle, the TRAMP NECa increased abundance of many amino acids, methyl donor S-adenosyl-methionine, and intermediates for phospholipids without increasing cholesteryl sulfate or ornithine.

CONCLUSIONS

The aqueous metabolomic patterns in Pten-KO prostate and TRAMP NECa shared similarities in the greater pools of cystathionine, GSH/GSSG redox pair, and nucleotides and shunting away from glycolysis-citrate cycle in both models. Remarkable metabolic distinctions between them included metabolisms of many amino acids (protein synthesis; arginine-ornithine/immune suppression) and cholesteryl sulfate and methylation donor for epigenetic regulations.

Role of PI3K-AKT-mTOR Pathway as a Pro-Survival Signaling and Resistance-Mediating Mechanism to Therapy of Prostate Cancer

Androgen deprivation therapy (ADT) and androgen receptor (AR)-targeted therapy are the gold standard options for treating prostate cancer (PCa). These are initially effective, as localized and the early stage of metastatic disease are androgen- and castration-sensitive. The tumor strongly relies on systemic/circulating androgens for activating AR signaling to stimulate growth and progression. However, after a certain point, the tumor will eventually develop a resistant stage, where ADT and AR antagonists are no longer effective. Mechanistically, it seems that the tumor becomes more aggressive through adaptive responses, relies more on alternative activated pathways, and is less dependent on AR signaling. This includes hyperactivation of PI3K-AKT-mTOR pathway, which is a central signal that regulates cell pro-survival/anti-apoptotic pathways, thus, compensating the blockade of AR signaling. The PI3K-AKT-mTOR pathway is well-documented for its crosstalk between genomic and non-genomic AR signaling, as well as other signaling cascades. Such a reciprocal feedback loop makes it more complicated to target individual factor/signaling for treating PCa. Here, we highlight the role of PI3K-AKT-mTOR signaling as a resistance mechanism for PCa therapy and illustrate the transition of prostate tumor from AR signaling-dependent to PI3K-AKT-mTOR pathway-dependent. Moreover, therapeutic strategies with inhibitors targeting the PI3K-AKT-mTOR signal used in clinic and ongoing clinical trials are discussed.

Natural resorcylic acid lactones: A chemical biology approach for anticancer activity

Resorcylic acid lactones (RALs) are fungal polyketides that consist of a β-resorcylic acid residue (2,4-dihydroxybenzoic acid) embedded in a macrolactone ring. RALs exhibit a broad range of biological activities, including anticancer activities. Following discovery of the selective Hsp90 inhibition activity of radicicol, the kinase inhibition activity of hypothemycin, monocillin II, 5Z-7-oxo-zeaenol, and L-783,277 RALs, and the nuclear factor kappa B (NF-κB) inhibition activity of the RAL zearalenone, have attracted great attention as potential therapeutics for cancer treatment. In this minireview, we focus on natural RALs that possess cytotoxic activities [IC₅₀ values < 10 μM (or 4-5 μg/ml)], discussing their structures, isolation, occurrence, biological activities, and anticancer molecular mechanisms.

JPX and LINC00641 ncRNAs expression in prostate tissue: a case-control study

Background and purpose

Prostate cancer (PC) is the second most prevalent cancer in men. Prostate-specific antigen (PSA) is the main biomarker for screening PC. An increase in PSA could lead to false-positive results. Thus, more appropriate markers should be investigated. In the present study, JPX and LINC00641 expression levels were measured in tumoral prostate tissue compared with the non-tumor tissue.

Experimental approach

43 pairs of prostate tumoral and non-tumor tissue were prepared. The expression levels of JPX and LINC00641 were investigated by RT-qPCR.

Findings/Results

Significant upregulation of LINC00641 (2.47 ± 0.5 vs 1.41 ± 0.2) and downregulation of JPX (1.42 ± 0.6 vs 2.83 ± 1.0) were observed in PC tissues compared with the normal tissues (their adjacent non-tumoral tissues).

Conclusion and implications

Dysregulation of JPX and LINC00641 in PC patients could be used in the future as a prognostic biomarker in PC.

Independent prognostic impact of plasma NCOA2 alterations in metastatic castration-resistant prostate cancer

BACKGROUND

The androgen receptor (AR) pathway-associated gene nuclear receptor coactivator 2 (NCOA2) has an established oncogenic role in early prostate cancer and likewise is a driver of metastatic disease and castration-resistant prostate cancer. However, its significance as a biomarker in metastatic castration-resistant prostate cancer (mCRPC), both alone and in conjunction with co-occurring AR alterations using a liquid biopsy approach has not been investigated.

METHODS

Ninety-one patients were included in this study, (n = 68 receiving an androgen receptor pathway inhibitor and n = 23 receiving taxane chemotherapy). Up to 30 ml of peripheral blood was collected before commencing treatment from each patient. Plasma cell-free DNA, along with a matched germline sample, underwent targeted next-generation sequencing using a validated, highly sensitive in-house prostate cancer panel. Variants in AR and NCOA2 were identified and correlated with clinical outcomes.

RESULTS

Plasma AR and NCOA2 aberrations were identified in 35% and 13% of the cohort, respectively, whilst 8% had concurrent AR and NCOA2 alterations. NCOA2 copy number gain and any NCOA2 aberration predicted for lower prostate-specific antigen (PSA) response rates. Likewise, median overall survival was shorter for NCOA2 gain (10.1 vs. 18.3 months; p = .004), remaining significant after adjusting for covariates including circulating tumor DNA fraction and tumor suppressor gene alterations. Importantly, dual AR and NCOA2 aberrations were also associated with inferior outcomes, including no PSA responses in patients treated with AR pathway inhibitors (0% vs. 64%; p = .02).

CONCLUSIONS

These data highlight the importance of identifying multiple markers of AR pathway modulation in mCRPC and represent the first instance of the assessment of plasma NCOA2 status as a prognostic biomarker for standard-of-care therapies. Further assessment is warranted to determine if NCOA2 aberrations are a marker of primary resistance to AR pathway inhibitors.

BAZ2A-mediated repression via H3K14ac-marked enhancers promotes prostate cancer stem cells

Prostate cancer (PCa) is one of the most prevalent cancers in men. Cancer stem cells are thought to be associated with PCa relapse. Here, we show that BAZ2A is required for PCa cells with a cancer stem‐like state. BAZ2A genomic occupancy in PCa cells coincides with H3K14ac‐enriched chromatin regions. This association is mediated by BAZ2A‐bromodomain (BAZ2A‐BRD) that specifically binds H3K14ac. BAZ2A associates with inactive enhancers marked by H3K14ac and repressing transcription of genes frequently silenced in aggressive and poorly differentiated PCa. BAZ2A‐mediated repression is also linked to EP300 that acetylates H3K14ac. BAZ2A‐BRD mutations or treatment with inhibitors abrogating BAZ2A‐BRD/H3K14ac interaction impair PCa stem cells. Furthermore, pharmacological inactivation of BAZ2A‐BRD impairs Pten‐loss oncogenic transformation of prostate organoids. Our findings indicate a role of BAZ2A‐BRD in PCa stem cell features and suggest potential epigenetic‐reader therapeutic strategies to target BAZ2A in aggressive PCa.

Quercetin and Luteolin Improve the Anticancer Effects of 5-Fluorouracil in Human Colorectal Adenocarcinoma In Vitro Model: A Mechanistic Insight

The aim of this study was to investigate the antitumor effects of quercetin and luteolin combined with 5-Fluorouracil (5-FU) in HT-29 human colorectal cancer cells. Cell viability induced by quercetin, luteolin and combination of these compounds with 5-FU were determined by MTT assay, also Cell death detection Elisa assay and fluorescence microscopy were performed to investigate apoptotic effects. Hu-VEGF Elisa assay was employed to determine the effects of treatments on angiogenesis. Western blot and qRT-PCR analysis were performed to investigate effects on p53, Bax, Bcl-2, p38 MAPK, mTOR, PTEN, and Akt proteins and genes. The results indicated that quercetin, luteolin and combinations of these compounds with 5-FU inhibited the growth of HT 29 cells. Compared to the control, apoptosis were triggered 8.1 and 10.1 fold in HT-29 cells, that treated with quercetin + 5-FU and luteolin + 5-FU, respectively. VEGF amount significantly decreased by combined treatments. qRT-PCR and western blot results demonstrated that quercetin, luteolin and the combinations of these flavonoids with 5-FU, modulate the apoptotic pathways in HT-29 cells. The increase in p53, Bax, p38 MAPK, and PTEN gene expression levels compared to the control group was 1.71, 1.42, 3.26, and 3.29-fold with 5-FU + L treatment, respectively, while this increase was 8.43, 1.65, 3.55, and 3.54-fold with 5-FU + Q treatment, respectively. In addition, when the anti-apoptotic Bcl-2, mTOR, and Akt gene expression levels were normalized as 1 in the control group, they were 0.28, 0.41, and 0.22 with 5-FU + L treatment, and 0.32, 0.46, and 0.39, respectively, with 5-FU + Q treatment. These findings suggested that quercetin and luteolin synergistically enhanced the anticancer effect of 5-FU in HT 29 cells and may therefore minimize the toxic effects of 5-FU in the clinical treatment of colorectal cancer.

Prostate Cancer Biomarkers: From diagnosis to prognosis and precision-guided therapeutics

Prostate cancer (PCa) is one of the most commonly diagnosed malignancies and among the leading causes of cancer-related death worldwide. It is a highly heterogeneous disease, ranging from remarkably slow progression or inertia to highly aggressive and fatal disease. As therapeutic decision-making, clinical trial design and outcome highly depend on the appropriate stratification of patients to risk groups, it is imperative to differentiate between benign versus more aggressive states. The incorporation of clinically valuable prognostic and predictive biomarkers is also potentially amenable in this process, in the timely prevention of metastatic disease and in the decision for therapy selection. This review summarizes the progress that has so far been made in the identification of the genomic events that can be used for the classification, prediction and prognostication of PCa, and as major targets for clinical intervention. We include an extensive list of emerging biomarkers for which there is enough preclinical evidence to suggest that they may constitute crucial targets for achieving significant advances in the management of the disease. Finally, we highlight the main challenges that are associated with the identification of clinically significant PCa biomarkers and recommend possible ways to overcome such limitations.

Decoding the heterogeneous landscape in the development prostate cancer

Prostate cancer (PCa) is characterized as being histologically and molecularly heterogeneous; however, this is not only incorrect among individuals, but also at the multiple foci level, which originates in the prostate gland itself. The reasons for such heterogeneity have not been fully elucidated; however, understanding these may be crucial in determining the course of the disease. PCa is characterized by a complex network of chromosomal rearrangements, which simultaneously deregulate multiple genes; this could explain the appearance of exclusive events associated with molecular subtypes, which have been extensively investigated to establish clinical management and the development of therapies targeted to this type of cancer. From a clinical aspect, the prognosis of the patient has focused on the characteristics of the index lesion (the largest focus in PCa); however, a significant percentage of patients (11%) also exhibit an aggressive secondary foci, which may determine the prognosis of the disease, and could be the determining factor of why, in different studies, the classification of the subtypes does not have an association with prognosis. Due to the aforementioned reasons, the analysis of molecular subtypes in several foci, from the same individual could assist in determining the association between clinical evolution and management of patients with PCa. Castration-resistant PCa (CRPC) has the worst prognosis and develops following androgen ablation therapy. Currently, there are two models to explain the development of CRPC: i) The selection model and ii) the adaptation model; both of which, have been found to include alterations described in the molecular subtypes, such as Enhancer of zeste 2 polycomb repressive complex 2 subunit overexpression, isocitrate dehydrogenase (NAPD⁺)1 and forkhead box A1 mutations, suggesting that the presence of specific molecular alterations could predict the development of CRPC. This type of analysis could lead to a biological understanding of PCa, to develop personalized medicine strategies, which could improve the response to treatment thus, avoiding the development of resistance. Therefore, the present review discusses the primary molecular factors, to which variable heterogeneity in PCa progress has been attributed.

Tumor Suppressors Having Oncogenic Functions: The Double Agents

Cancer progression involves multiple genetic and epigenetic events, which involve gain-of-functions of oncogenes and loss-of-functions of tumor suppressor genes. Classical tumor suppressor genes are recessive in nature, anti-proliferative, and frequently found inactivated or mutated in cancers. However, extensive research over the last few years have elucidated that certain tumor suppressor genes do not conform to these standard definitions and might act as “double agents”, playing contrasting roles in vivo in cells, where either due to haploinsufficiency, epigenetic hypermethylation, or due to involvement with multiple genetic and oncogenic events, they play an enhanced proliferative role and facilitate the pathogenesis of cancer. This review discusses and highlights some of these exceptions; the genetic events, cellular contexts, and mechanisms by which four important tumor suppressors—pRb, PTEN, FOXO, and PML display their oncogenic potentials and pro-survival traits in cancer.

Calcium cytotoxicity sensitizes prostate cancer cells to standard-of-care treatments for locally advanced tumors

Therapy resistance is a major roadblock in oncology. Exacerbation of molecular dysfunctions typical of cancer cells have proven effective in twisting oncogenic mechanisms to lethal conditions, thus offering new therapeutic avenues for cancer treatment. Here, we demonstrate that selective agonists of Transient Receptor Potential cation channel subfamily M member 8 (TRPM8), a cation channel characteristic of the prostate epithelium frequently overexpressed in advanced stage III/IV prostate cancers (PCa), sensitize therapy refractory models of PCa to radio, chemo or hormonal treatment. Overall, our study demonstrates that pharmacological-induced Ca²⁺ cytotoxicity is an actionable strategy to sensitize cancer cells to standard therapies.

Why All the Fuss about Oxidative Phosphorylation (OXPHOS)?

Certain subtypes of cancer cells require oxidative phosphorylation (OXPHOS) to survive. Increased OXPHOS dependency is frequently a hallmark of cancer stem cells and cells resistant to chemotherapy and targeted therapies. Suppressing the OXPHOS function might also influence the tumor microenvironment by alleviating hypoxia and improving the antitumor immune response. Thus, targeting OXPHOS is a promising strategy to treat various cancers. A growing arsenal of therapeutic agents is under development to inhibit this biological process. This Perspective provides an overview of the structure and function of OXPHOS complexes, their biological functions in cancer, relevant research tools and models, as well as the limitations of OXPHOS as drug targets. We also focus on the current development status of OXPHOS inhibitors and potential therapeutic strategies to strengthen their clinical applications.

The PTEN Conundrum: How to Target PTEN-Deficient Prostate Cancer

Loss of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN), which negatively regulates the PI3K-AKT-mTOR pathway, is strongly linked to advanced prostate cancer progression and poor clinical outcome. Accordingly, several therapeutic approaches are currently being explored to combat PTEN-deficient tumors. These include classical inhibition of the PI3K-AKT-mTOR signaling network, as well as new approaches that restore PTEN function, or target PTEN regulation of chromosome stability, DNA damage repair and the tumor microenvironment. While targeting PTEN-deficient prostate cancer remains a clinical challenge, new advances in the field of precision medicine indicate that PTEN loss provides a valuable biomarker to stratify prostate cancer patients for treatments, which may improve overall outcome. Here, we discuss the clinical implications of PTEN loss in the management of prostate cancer and review recent therapeutic advances in targeting PTEN-deficient prostate cancer. Deepening our understanding of how PTEN loss contributes to prostate cancer growth and therapeutic resistance will inform the design of future clinical studies and precision-medicine strategies that will ultimately improve patient care.

IMP3 accelerates the progression of prostate cancer through inhibiting PTEN expression in a SMURF1-dependent way

BACKGROUND

Insulin-like growth factor 2 (IGF2) messenger RNA binding protein 3 (IMP3) has been testified to be overexpressed in prostate cancer and strongly related to patients' poor prognosis. However, the functions of IMP3 and the underlying mechanisms in prostate cancer still remain unknown. Therefore, the current study was carried out to reveal the role and molecular mechanism of IMP3 in prostate cancer progression.

METHODS

The expression levels of IMP3 in prostate cancer tissues and cells were detected by immunohistochemistry (IHC), western blotting and RT-PCR. CCK-8, clone formation, flow cytometry and in vivo tumor formation assays were used to determine cell growth, clone formation apoptosis and tumorigenesis, respectively. The effect of IMP3 on the expression levels of the key proteins in PI3K/AKT/mTOR signaling pathway, including PIP2, PIP3, p-AKT, AKT, p-mTOR, mTOR, PTEN and BAD activation of was determined by western blotting. IP (Immunoprecipitation) assay was used to evaluate the effects of IMP3 and SMURF1 (SMAD specific E3 ubiquitin protein ligase 1) on the ubiquitination of PTEN protein.

RESULTS

IMP3 expression level was significantly increased in prostate cancer tissues and cell lines (LNCap, PC3 and DU145) as compared with the paracancerous normal tissues and cells (RWPE-1), respectively. High expression of IMP3 apparently promoted cell viability, tumorigenesis and inhibited cell apoptosis in prostate cancer LNCap, DU145 and PC3 cell lines. In mechanism, IMP3 upregulation significantly increased the phosphorylation levels of AKT and mTOR, and elevated PIP3 expression level, while induced significant reductions in the expression levels of BAD, PTEN and PIP2. And, IMP3 overexpression increased SMURF1 expression, which facilitated PTEN ubiquitination. In addition, SMURF1 overexpression enhanced prostate cancer cell viability and inhibited cell apoptosis. Silence of SMURF1 rescued the enhancements in cell proliferation and tumorigenesis and the inhibition in cell apoptosis rates induced by IMP3 in prostate cancer DU145 and LNCap cells.

CONCLUSION

This study reveals that IMP3 is overdressed in prostate cancer, which accelerates the progression of prostate cancer through activating PI3K/AKT/mTOR signaling pathway via increasing SMURF1-mediated PTEN ubiquitination.

Grape Powder Supplementation Attenuates Prostate Neoplasia Associated with Pten Haploinsufficiency in Mice Fed High-Fat Diet

SCOPE

Previous studies have identified potent anticancer activities of polyphenols in preventing prostate cancer. The aim of the current study is to evaluate the chemopreventive potential of grape powder (GP) supplemented diets in genetically predisposed and obesity-provoked prostate cancer.

METHODS AND RESULTS

Prostate-specific Pten heterozygous (Pten+/f ) transgenic mice are fed low- and high-fat diet (LFD and HFD, respectively) supplemented with 10% GP for 33 weeks, ad libitum. Prostate tissues are characterized using immunohistochemistry and western blots, and sera are analyzed by ELISA and qRT-PCR. Pten+/f mice fed LFD and HFD supplemented with 10% GP show favorable histopathology, significant reduction of the proliferative rate of prostate epithelial cells (Ki67), and rescue of PTEN expression. The most potent protective effect of GP supplementation is detected against HFD-induced increase in inflammation (IL-1β; TGF-β1), activation of cell survival pathways (Akt, AR), and angiogenesis (CD31) in Pten+/f mice. Moreover, GP supplementation reduces circulating levels of oncogenic microRNAs (miR-34a; miR-22) in Pten+/f mice. There are no significant changes in body weight and food intake in GP supplemented diet groups.

CONCLUSIONS

GP diet supplementation can be a beneficial chemopreventive strategy for obesity-related inflammation and prostate cancer progression. Monitoring serum miRNAs can facilitate the non-invasive evaluation of chemoprevention efficacy.

Clinical and functional characterization of CXCR1/CXCR2 biology in the relapse and radiotherapy resistance of primary PTEN-deficient prostate carcinoma

Functional impairment of the tumour suppressor PTEN is common in primary prostate cancer and has been linked to relapse post-radiotherapy (post-RT). Pre-clinical modelling supports elevated CXC chemokine signalling as a critical mediator of PTEN-depleted disease progression and therapeutic resistance. We assessed the correlation of PTEN deficiency with CXC chemokine signalling and its association with clinical outcomes. Gene expression analysis characterized a PTEN ^LOW/CXCR1^HIGH/CXCR2^HIGH cluster of tumours that associates with earlier time to biochemical recurrence [hazard ratio (HR) 5.87 and 2.65, respectively] and development of systemic metastasis (HR 3.51). In vitro, CXCL signalling was further amplified following exposure of PTEN-deficient prostate cancer cell lines to ionizing radiation (IR). Inhibition of CXCR1/2 signalling in PTEN-depleted cell-based models increased IR sensitivity. In vivo, administration of a CXCR1/2-targeted pepducin (x1/2pal-i3), or CXCR2-specific antagonist (AZD5069), in combination with IR to PTEN-deficient xenografts attenuated tumour growth and progression compared to control or IR alone. Post-mortem analysis confirmed that x1/2pal-i3 administration attenuated IR-induced CXCL signalling and anti-apoptotic protein expression. Interventions targeting CXC chemokine signalling may provide an effective strategy to combine with RT in locally advanced prostate cancer patients with known presence of PTEN-deficient foci.

PTEN Alterations and Their Role in Cancer Management: Are We Making Headway on Precision Medicine?

Alterations in the tumor suppressor phosphatase and tensin homolog (PTEN) occur in a substantial proportion of solid tumors. These events drive tumorigenesis and tumor progression. Given its central role as a downregulator of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, PTEN is deeply involved in cell growth, proliferation, and survival. This gene is also implicated in the modulation of the DNA damage response and in tumor immune microenvironment modeling. Despite the actionability of PTEN alterations, their role as biomarkers remains controversial in clinical practice. To date, there is still a substantial lack of validated guidelines and/or recommendations for PTEN testing. Here, we provide an update on the current state of knowledge on biologic and genetic alterations of PTEN across the most frequent solid tumors, as well as on their actual and/or possible clinical applications. We focus on possible tailored schemes for cancer patients' clinical management, including risk assessment, diagnosis, prognostication, and treatment.

Epigenetic regulation of prostate cancer: the theories and the clinical implications

Epigenetics is the main mechanism that controls transcription of specific genes with no changes in the underlying DNA sequences. Epigenetic alterations lead to abnormal gene expression patterns that contribute to carcinogenesis and persist throughout disease progression. Because of the reversible nature, epigenetic modifications emerge as promising anticancer drug targets. Several compounds have been developed to reverse the aberrant activities of enzymes involved in epigenetic regulation, and some of them show encouraging results in both preclinical and clinical studies. In this article, we comprehensively review the up-to-date roles of epigenetics in the development and progression of prostate cancer. We especially focus on three epigenetic mechanisms: DNA methylation, histone modifications, and noncoding RNAs. We elaborate on current models/theories that explain the necessity of these epigenetic programs in driving the malignant phenotypes of prostate cancer cells. In particular, we elucidate how certain epigenetic regulators crosstalk with critical biological pathways, such as androgen receptor (AR) signaling, and how the cooperation dynamically controls cancer-oriented transcriptional profiles. Restoration of a "normal" epigenetic landscape holds promise as a cure for prostate cancer, so we concluded by highlighting particular epigenetic modifications as diagnostic and prognostic biomarkers or new therapeutic targets for treatment of the disease.

Integrative Exome Sequencing Analysis in Castration-Resistant Prostate Cancer in Chinese Population

BACKGROUND

Castration-resistant Prostate Cancer (CRPC) is a fatal disease with rapid growth. The malignancy usually presents with metastasis and poor prognosis, and causes 100% mortality. Therefore, the treatment of CRPC is extremely challenging, and its pathogenesis need to be elucidated urgently.

OBJECTIVE

The high throughput sequencing technology was used to sequence the whole exome associated with CRPC, to explore the molecular mechanism of CRPC, and to find the potential therapeutic targets.

METHODS

We performed whole-exome sequencing of FFPE tissue from 11 Chinese adult male patients. Genomic DNA was fragmented and enriched for whole-exome sequencing using the QiAamp DNA FFPE Tissue KIT, sequenced on an Illumina HiSeq2000 platform, and the relevant genes were analyzed using biological information. Finally, immunohistochemistry method was used to detect the phosphorylation level of LATS1 in CRPC tissues of MST1 mutant and non-mutant patients.

RESULTS

We have screened 85 significant mutant genes with relatively high mutation rates of TP53, AR, KMT2, DMAPK1, PIK3R1, SH2B3, WHSC1, KMT2D, MST1 and MAPK1. We first found that MST1 has multiple mutations in CRPC patients, and the MST1 plays an important role in the Hippo pathway. Immunohistochemistry results showed that the phosphorylation level of LATS1 in the mutant patients was significantly lower than that in the non-mutant patients.

CONCLUSION

We speculate that MST1 would be a new potential target for the treatment of CRPC by regulating Hippo signaling pathway. The results provided an important clue to the molecular mechanism of CRPC.

LncARSR promotes non-small-cell lung cancer progression via regulating PTEN/Akt

LncRNAs have been suggested to be key modulators in many biological and pathological processes. LncARSR, a recently identified lncRNA, plays crucial roles in the progression of several cancers. However, the role of lncARSR in NSCLC is uninvestigated. In the present study, it was demonstrated that lncARSR expression was higher in NSCLC tissues than in noncancerous tissues. The expression of lncARSR was higher in four NSCLC cell lines than in a normal lung bronchial epithelial line. Further investigation demonstrated that increased lncARSR expression promoted NSCLC cell migration and growth and induced epithelial-mesenchymal transition in A549 cells. Moreover, ectopic expression of lncARSR suppressed PTEN expression and induced Akt phosphorylation in A549 cells. The expression level of PTEN was higher in NSCLC samples than in adjacent non-tumor specimens. PTEN expression was negatively correlated with lncARSR in NSCLC specimens. Furthermore, we demonstrated that overexpression of lncARSR induced NSCLC cell growth and migration via regulating the PTEN/Akt signaling pathway. These results suggest that lncARSR acts as an oncogene in NSCLC development and could serve as a new potential therapeutic target.

TIP5 primes prostate luminal cells for the oncogenic transformation mediated by PTEN-loss

The cell of origin and the temporal order of oncogenic events in tumors play important roles for disease state. This is of particular interest for PCa due to its highly variable clinical outcome. However, these features are difficult to analyze in tumors. We established an in vitro murine PCa organoid model taking into account the cell of origin and the temporal order of events. We found that TIP5 primes luminal prostate cells for Pten-loss mediated oncogenic transformation whereas it is dispensable once the transformation is established. Cross-species transcriptomic analyses revealed a PTEN-loss gene signature that identified a set of aggressive tumors with PTEN-del, or low PTEN expression, and high-TIP5 expression. This paper provides a powerful tool to elucidate PCa mechanisms.

Prostate cancer (PCa) is the second leading cause of cancer death in men. Its clinical and molecular heterogeneities and the lack of in vitro models outline the complexity of PCa in the clinical and research settings. We established an in vitro mouse PCa model based on organoid technology that takes into account the cell of origin and the order of events. Primary PCa with deletion of the tumor suppressor gene PTEN (PTEN-del) can be modeled through Pten-down-regulation in mouse organoids. We used this system to elucidate the contribution of TIP5 in PCa initiation, a chromatin regulator that is implicated in aggressive PCa. High TIP5 expression correlates with primary PTEN-del PCa and this combination strongly associates with reduced prostate-specific antigen (PSA) recurrence-free survival. TIP5 is critical for the initiation of PCa of luminal origin mediated by Pten-loss whereas it is dispensable once Pten-loss mediated transformation is established. Cross-species analyses revealed a PTEN gene signature that identified a group of aggressive primary PCas characterized by PTEN-del, high-TIP5 expression, and a TIP5-regulated gene expression profile. The results highlight the modeling of PCa with organoids as a powerful tool to elucidate the role of genetic alterations found in recent studies in their time orders and cells of origin, thereby providing further optimization for tumor stratification to improve the clinical management of PCa.

Merging new-age biomarkers and nanodiagnostics for precision prostate cancer management

The accurate identification and stratified treatment of clinically significant early-stage prostate cancer have been ongoing concerns since the outcomes of large international prostate cancer screening trials were reported. The controversy surrounding clinical and cost benefits of prostate cancer screening has highlighted the lack of strategies for discriminating high-risk disease (that requires early treatment) from low-risk disease (that could be managed using watchful waiting or active surveillance). Advances in molecular subtyping and multiomics nanotechnology-based prostate cancer risk delineation can enable refinement of prostate cancer molecular taxonomy into clinically meaningful and treatable subtypes. Furthermore, the presence of intertumoural and intratumoural heterogeneity in prostate cancer warrants the development of novel nanodiagnostic technologies to identify clinically significant prostate cancer in a rapid, cost-effective and accurate manner. Circulating and urinary next-generation prostate cancer biomarkers for disease molecular subtyping and the newest complementary nanodiagnostic platforms for enhanced biomarker detection are promising tools for precision prostate cancer management. However, challenges in merging both aspects and clinical translation still need to be overcome.

Diagnostic Value of 68Ga-PSMA PET/CT for Detection of Phosphatase and Tensin Homolog Expression in Prostate Cancer: A Pilot Study

Our purpose was to explore the value of ⁶⁸Ga-prostate-specific membrane antigen (PSMA) PET/CT for detection of phosphatase and tensin homolog (PTEN)-loss prostate cancer. Methods: We retrospectively enrolled 75 patients who underwent multiparametric MRI and ⁶⁸Ga-PSMA PET/CT before radical prostatectomy. Lesions were outlined on pathologic images, and regions of interest were drawn on matched multiparametric MRI and PET/CT images. Imaging parameters, including average apparent diffusion coefficient and SUV_max, were derived. Immunohistochemical staining was performed to evaluate the PTEN status. The diagnostic performance of imaging parameters was analyzed by receiver-operating-characteristic analysis. Univariate logistic regression analyses were used to evaluate the association between clinical and imaging variables and PTEN status. Results: In total, 103 lesions from 75 patients were analyzed. Of these lesions, 38 of 103 (36.9%) showed PTEN-loss status. Our study showed a strong association between SUV_max and PTEN-loss tumors both in the per-patient analysis (P < 0.01) and in the per-lesion analysis (P < 0.01), yielding sensitivity and specificity of 0.80 and 0.77, respectively, in the per-patient analysis and 0.83 and 0.74, respectively, in the per-lesion analysis. Meanwhile, higher pathologic PSMA expression was found in the PTEN-deficiency tumors. However, there was no significant difference between PTEN-loss tumors and PTEN-intact tumors using parameters such as average apparent diffusion coefficient (P > 0.05) and score on the Prostate Imaging Reporting and Data System, version 2 (P > 0.05). Surprisingly, SUV_max was a significant predictor for detection of PTEN-loss tumors (odds ratio of 7.56 and 95% confidence interval of 2.18-26.24 on per-patient analysis; odds ratio of 13.66 and 95% confidence interval of 4.32-43.24 on per-lesion analysis). Conclusion: ⁶⁸Ga-PSMA PET/CT could effectively detect aggressive PTEN-loss tumors.

6-gene promoter methylation assay is potentially applicable for prostate cancer clinical staging based on urine collection following prostatic massage

The detection of prostate cancer (PCa) biomarkers in bodily fluids, a process known as liquid biopsy, is a promising approach and particularly beneficial when performed in urine samples due to their maximal non-invasiveness requirement of collection. A number of gene panels proposed for this purpose have allowed discrimination between disease-free prostate and PCa; however, they bear no significant prognostic value. With the purpose to develop a gene panel for PCa diagnosis and prognosis, the methylation status of 17 cancer-associated genes were analyzed in urine cell-free DNA obtained from 31 patients with PCa and 33 control individuals using methylation-specific polymerase chain reaction (MSP). Among these, 13 genes indicated the increase in methylation frequency in patients with PCa compared with controls. No prior association has been reported between adenomatosis polyposis coli 2 (APC2), homeobox A9, Wnt family member 7A (WNT7A) and N-Myc downstream-regulated gene 4 protein genes with PCa. The 6-gene panel consisting of APC2, cadherin 1, forkhead box P1, leucine rich repeat containing 3B, WNT7A and zinc family protein of the cerebellum 4 was subsequently developed providing PCa detection with 78% sensitivity and 100% specificity. The number of genes methylated (NGM) value introduced for this panel was indicated to rise monotonically from 0.27 in control individuals to 4.6 and 4.25 in patients with highly developed and metastatic T₂/T₃ stage cancer, respectively. Therefore, the approach of defining the NGM value may not only allow for the detection of PCa, but also provide a rough evaluation of tumor malignancy and metastatic potential by non-invasive MSP analysis of urine samples.

MicroRNA biogenesis, gene silencing mechanisms and role in breast, ovarian and prostate cancer

Micro-ribonucleic acids (miRNAs) are important class of short regulatory RNA molecules involved in regulation of several essential biological processes. In addition to Dicer and Drosha, over the past few years several other gene products are discovered that regulates miRNA biogenesis pathways. Similarly, various models of molecular mechanisms underlying miRNA mediated gene silencing have been uncovered through which miRNA contribute in diverse physiological and pathological processes. Dysregulated miRNA expression has been reported in many cancers manifesting tumor suppressive or oncogenic role. In this review, critical overview of recent findings in miRNA biogenesis, silencing mechanisms and specifically the role of miRNA in breast, ovarian and prostate cancer will be described. Recent advancements in miRNA research summarized in this review will enhance the molecular understanding of miRNA biogenesis and mechanism of action. Also, role of miRNAs in pathogenesis of breast, ovarian and prostate cancer will provide the insights for the use of miRNAs as biomarker or therapeutic agents for the cancers.

Novel Poly(Adenosine Diphosphate-Ribose) Polymerase (PARP) Inhibitor, AZD2461, Down-Regulates VEGF and Induces Apoptosis in Prostate Cancer Cells

Background

Prostate cancer (Pca) is a heterogeneous disease, and current treatments are not based on molecular stratification. Poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors have recently been found to be remarkably toxic to cells with defects in homologous recombination, particularly cells with BRCA-mutated backgrounds. Therefore, this preliminary study was designed to evaluate whether PTEN expression status could have an impact on the sensitivity of invasive Pca cells to the PARP inhibitor, AZD2461.

Methods

MTT viability test, Annexin V‐FITC/propidium iodide double staining, and caspase3 activity assay were used to evaluate the apoptosis and relative expression of PTEN and VEGF in PC-3 and DU145 cell lines using real-time PCR.

Results

MTT results showed that the inhibitory effects of AZD2461 were higher in PC-3 than DU145 cells (with IC50 of 36.48 and 59.03 µM at 48 hours of treatment, respectively). Flow cytometric analysis also showed the same results. When exposed to 40 µM of AZD2461, PC-3 (38.8%) and DU145 (28%) cells underwent apoptosis (p < 0.05). Treatment of cells by AZD2461 also caused a significant increase in apoptosis through caspase3 activation in both cell lines. VEGF mRNA levels in PC-3 cells significantly decreased compared to adjusted untreated cells (p < 0.05) in all measured times while displaying different alteration patterns in DU145 cells (p < 0.05).

Conclusion

AZD2461 suppresses the growth of prostate tumor cells since AZD2461 monotherapy could prove to be efficacious, especially against cells not expressing PTEN besides activating the possible apoptosis-independent cell death pathways.

Induction of apoptosis and modulation of homologous recombination DNA repair pathway in prostate cancer cells by the combination of AZD2461 and valproic acid

Cancer therapies using defects in homologous recombination (HR) DNA repair pathway of tumor cells are not yet approved to be applicable in patients with malignancies other than BRCA1/2-mutated tumors. This study was designed to determine the efficacy of combination therapy of a histone deacetylase inhibitor, valproic acid (VPA) and a novel PARP inhibitor AZD2461 in both PC-3 (PTEN-mutated) and DU145 (PTEN-unmutated) prostate cancer cell lines. The Trypan blue dye exclusion assay and the tetrazolium-based colorimetric (MTT) assay were performed to measure the cytotoxicity while combination effects were assessed based on Chou-Talalay's principles. Flow-cytometric assay determined the type of cell death. The real-time PCR analysis was used to evaluate the alterations in mRNA levels of HR-related genes while their protein levels were measured using the ELISA method. γ-H2AX levels were determined as a marker of DNA damage. We observed a synergistic relationship between VPA and AZD2461 in all affected fractions of PC-3 cells (CI<0.9), but not in DU145 cells (CI>1.1). Annexin-V staining analysis revealed a significant induction of apoptosis when PC-3 cells were treated with VPA+AZD2461 (p<0.05). Both mRNA and protein levels of Rad51 and Mre11 were significantly decreased in PC-3 cells co-treated with VPA+AZD2461 while enhanced H2AX phosphorylation was found in PC-3 cells after 12 and 24 hours of co-treatment (p<0.05). Our findings established a preclinical rationale for selective targeting of HR repair pathways by a combination of VPA and AZD2461 as a mechanism for reducing the HR pathway sufficiency in PTEN-mutated prostate cancer cells.

Identifying small molecule probes of ENTPD5 through high throughput screening

Ectonucleoside Triphosphate Diphosphohydrolase 5 (ENTPD5) has been shown to be important in maintaining cellular function in cancer, and its expression is upregulated through multiple, unique pathways in certain cancers, including laryngeal, glioblastoma multiforme, breast, testicular, and prostate. ENTPD5 supports cancer growth by promoting the import of UDP-glucose, a metabolite used for protein glycosylation and hence proper glycoprotein folding, into the ER by providing the counter molecule, UMP, to the ER antiporter. Despite its cancer-supporting function, no small molecule inhibitors of ENTPD5 are commercially available, and few studies have been performed in tissue culture to understand the effects of chemical inhibition of ENTPD5. We performed a high-throughput screen (HTS) of 21,120 compounds to identify small molecule inhibitors of ENPTD5 activity. Two hits were identified, and we performed a structure activity relationship (SAR) screen around these hits. Further validation of these probes were done in an orthogonal assay and then assayed in cell culture to assess their effect on prostate cancer cell lines. Notably, treatment with the novel ENTPD5 inhibitor reduced the amount of glycoprotein produced in treated cells, consistent with the hypothesis that ENTPD5 is important for glycoprotein folding. This work serves as an important step in designing new molecular probes for ENTPD5 as well as further probing the utility of targeting ENTPD5 to combat cancer cell proliferation.

PTEN Expression in Prostate Cancer: Relationship With Clinicopathologic Features and Multiparametric MRI Findings

OBJECTIVE. The objective of our study was to investigate whether phosphatase and tensin homolog (PTEN) expression is associated with clinicopathologic features and multiparametric MRI findings in prostate cancer. MATERIALS AND METHODS. Forty-three patients with prostate cancer who underwent radical prostatectomy were included. Index tumor was identified on pretreatment MRI and delineated in the area that correlated best with histopathology results. The apparent diffusion coefficient (ADC) from DWI and pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Tofts model (K^trans, k_ep, v_e, and v_p) within the tumor were estimated. The following clinicopathologic parameters were assessed: pretreatment serum levels of prostate-specific antigen, disseminated tumor cell status, age, Gleason score, tumor size, extraprostatic extension (EPE), tumor location, and lymph node metastases. Gene expression profiles were acquired in biopsies from the tumor using bead arrays, and validated using reverse transcription quantitative polymerase chain reaction (RT-qPCR) on a different part of the biopsy. RESULTS. Based on bead arrays (p = 0.006) and RT-qPCR (p = 0.03) data, a significantly lower ADC was found in tumors with low PTEN expression. Moreover, PTEN expression was negatively associated with lymph node metastases (bead arrays, p = 0.008; RT-qPCR, p < 0.001). A weak but significant association between PTEN expression, EPE (p = 0.048), and Gleason score (p = 0.028) was revealed on bead arrays. ADC was negatively correlated with Gleason score (p = 0.001) and tumor size (p = 0.023). No association among DCE parameters, PTEN expression, and clinicopathologic features was found. CONCLUSION. ADC derived from DWI may be useful in selecting patients with potentially aggressive tumor caused by PTEN deficiency.

PIP-ing Lipids on Membranes: PTEN Takes the Cake

In this issue of Molecular Cell, Malek et al. (2017) describe a novel HPLC-MS method permitting separation of PI(3,4)P₂ and PI(4,5)P₂, a technical issue hindering the phosphoinositide signaling field. They use this method to uncover a new target and critical role for PTEN in cancer.

Complex Systems Biology Approach in Connecting PI3K-Akt and NF-κB Pathways in Prostate Cancer

Phosphatidylinositol 3′-OH kinase (PI3K)-Akt and transcription factor NF-κB are important molecules involved in the regulation of cell proliferation, apoptosis, and oncogenesis. Both PI3K-Akt and Nuclear Factor-kappaB (NF-κB) are involved in the development and progression of prostate cancer, however, the crosstalk and molecules connecting these pathway remains unclear. A multilevel system representation of the PI3K-Akt and NF-κB pathways was constructed to determine which signaling components contribute to adaptive behavior and coordination. In silico experiments conducted using PI3K-Akt and NF-κB, mathematical models were modularized using biological functionality and were validated using a cell culture system. Our analysis demonstrates that a component representing the IκB kinase (IKK) complex can coordinate these two pathways. It is expected that interruption of this molecule could represent a potential therapeutic target for prostate cancer.

The Secret Life of Translation Initiation in Prostate Cancer

Prostate cancer (PCa) is the second most prevalent cancer in men worldwide. Despite the advances understanding the molecular processes driving the onset and progression of this disease, as well as the continued implementation of screening programs, PCa still remains a significant cause of morbidity and mortality, in particular in low-income countries. It is only recently that defects of the translation process, i.e., the synthesis of proteins by the ribosome using a messenger (m)RNA as a template, have begun to gain attention as an important cause of cancer development in different human tissues, including prostate. In particular, the initiation step of translation has been established to play a key role in tumorigenesis. In this review, we discuss the state-of-the-art of three key aspects of protein synthesis in PCa, namely, misexpression of translation initiation factors, dysregulation of the major signaling cascades regulating translation, and the therapeutic strategies based on pharmacological compounds targeting translation as a novel alternative to those based on hormones controlling the androgen receptor pathway.

Loss of PSP94 expression is associated with early PSA recurrence and deteriorates outcome of PTEN deleted prostate cancers

Objective

Prostate secretory protein of 94 amino acids (PSP94) is a target gene of the EZH2 transcriptional repressor and is often downregulated in prostate cancer; however, its prognostic value is disputed.

Methods

Immunohistochemical analysis of a tissue microarray of 12, 432 prostate cancer specimens was performed to evaluate PSP94 expression. Correlation of PSP94 expression with tumor phenotype, patient prognosis, TMPRSS2:ERG fusion status, EZH2 expression and PTEN deletion was studied.

Results

PSP94 expression was increased in benign prostatic hyperplasia; however, it was downregulated in 48% and negative in 42% of the 9, 881 interpretable prostate cancer specimens. The loss of PSP94 expression was inversely correlated to EZH2 expression (P < 0.0001) and largely unrelated to the ERG status, but strongly correlated with high Gleason grade, advanced tumor stage, and nodal metastasis ( P <0.0001 each). The fraction of PSP94-negative cancer specimens increased from 40% in pT2 to 52% in pT3b-pT4 ( P < 0.0001) and from 40% in Gleason 3+3 = 6 to 46% in Gleason 4+3 = 7 and 60% in Gleason ≥4+4 = 8 ( P < 0.0001). Loss of PSP94 was linked to early prostate-specific antigen recurrence, but with little absolute effect ( P < 0.0001). However, it provided additional prognostic impact in cancer specimens with PTEN deletion. Loss of PSP94 deteriorated prognosis of cancer patients with PTEN deletion by more than 10% (P < 0.0001). The combination of PTEN deletion and PSP94 loss provided independent prognostic information that was observed in several subgroups defined by classical and quantitative Gleason grade.

Conclusions

The results of our study suggest that combined PSP94/PTEN analysis can be potentially used in the clinical prognosis of prostate cancer.

Afrocyclamin A, a triterpene saponin, induces apoptosis and autophagic cell death via the PI3K/Akt/mTOR pathway in human prostate cancer cells

BACKGROUND

Afrocyclamin A, an oleanane-type triterpene saponin, was isolated from Androsace umbellata which used as a traditional herbal medicine.

PURPOSE

This study aimed to explore the anticancer activity of afrocyclamin A on human prostate cancer cells in vitro as well as in vivo.

METHODS

Cytotoxicity, cell cycle distribution, apoptosis, and autophagic cell death were measured following exposure to afrocyclamin A. In vivo antitumor activity of afrocyclamin A was assessed in a xenograft model. The protein levels of p-Akt, p-mTOR, Bax, Bcl-2, caspase-3, and caspase-9 were quantified using western blot analysis.

RESULTS

In DU145 cells, afrocyclamin A increased cytotoxicity, caused changes in cell morphology, and induced sub-G0/G1 phase indicating increased apoptosis. Afrocyclamin A robustly induced autophagic cell death as demonstrated by the conversion of LC3B-I to LC3B-II, and the formation of autophagic vacuoles as revealed by western blot analysis and fluorescence staining, respectively. Afrocyclamin A also inhibited the phosphorylation of PI3K, Akt, and mTOR, suggesting their role in afrocyclamin A induced cell death. In addition, afrocyclamin A inhibited cell migration and invasion in concentration and time-dependent manners. In an in vivo xenograft model, afrocyclamin A inhibited the growth of DU145 cells.

CONCLUSION

Afrocyclamin A has anticancer activity via the PI3K/Akt/mTOR pathway, which leads to cell death.

Molecular Biomarkers in the Clinical Management of Prostate Cancer

Prostate cancer, one of the most common noncutaneous malignancies in men, is a heterogeneous disease with variable clinical outcome. Although the majority of patients harbor indolent tumors that are essentially cured by local therapy, subsets of patients present with aggressive disease or recur/progress after primary treatment. With this in mind, modern clinical approaches to prostate cancer emphasize the need to reduce overdiagnosis and overtreatment via personalized medicine. Advances in our understanding of prostate cancer pathogenesis, coupled with recent technologic innovations, have facilitated the development and validation of numerous molecular biomarkers, representing a range of macromolecules assayed from a variety of patient sample types, to help guide the clinical management of prostate cancer, including early detection, diagnosis, prognostication, and targeted therapeutic selection. Herein, we review the current state of the art regarding prostate cancer molecular biomarkers, emphasizing those with demonstrated utility in clinical practice.

Is miR-144 an effective inhibitor of PTEN mRNA: a controversy in breast cancer

Breast cancer is the first common cancer among women worldwide. One of the major signaling pathways playing a role in the onset and progression of this disease is PI3K/Akt/mTOR, which can be inhibited by PTEN. miRNAs are small non-coding molecules that regulate the expression of their targets by inhibition or suppression, and thus, their dysregulated expression results in the development of cancer. Using various software applications predicting miRNAs and evaluating GEO microarray data, miR-144 was selected as an inhibitor of PTEN. The expression of miR-144 and PTEN was evaluated in 18 triple negative breast cancer (TNBC) clinical samples and cell lines including 4T1, MDA-MB-231, MDA-MB-468, SK-BR-3, and MCF-7 in comparison with normal cells. PTEN and miR-144 expression analysis revealed their elevated expression in MCF-7 cells. MDA-MB-468, SK-BR-3, and MDA-MB-231 cells showed decreased levels of PTEN and increased levels of miR-144. In contrast, 4T1 cells had an increased expression of PTEN and decreased expression of miR-144. In clinical samples, miR-144 was up-regulated in 22% of the cases and PTEN was down-regulated in 78% of the cases. The results showed that the expression of PTEN and miR-144 was inversely correlated in metastatic breast cancer cell lines. However, in TNBC clinical samples, there was no correlation between the expression of miR-144 and PTEN. Literature shows that there are other influencing factors affecting the expression of miRNAs. Therefore, care should be taken in interpreting the results of gene expression studies and its relation with cancer diagnosis/prognosis.

PTEN Deficiency and AMPK Activation Promote Nutrient Scavenging and Anabolism in Prostate Cancer Cells

We report that PTEN-deficient prostate cancer cells use macropinocytosis to survive and proliferate under nutrient stress. PTEN loss increased macropinocytosis only in the context of AMPK activation, revealing a general requirement for AMPK in macropinocytosis and a novel mechanism by which AMPK promotes survival under stress. In prostate cancer cells, albumin uptake did not require macropinocytosis, but necrotic cell debris proved a specific macropinocytic cargo. Isotopic labeling confirmed that macropinocytosed necrotic cell proteins fueled new protein synthesis in prostate cancer cells. Supplementation with necrotic debris, but not albumin, also maintained lipid stores, suggesting that macropinocytosis can supply nutrients other than amino acids. Nontransformed prostatic epithelial cells were not macropinocytic, but patient-derived prostate cancer organoids and xenografts and autochthonous prostate tumors all exhibited constitutive macropinocytosis, and blocking macropinocytosis limited prostate tumor growth. Macropinocytosis of extracellular material by prostate cancer cells is a previously unappreciated tumor-microenvironment interaction that could be targeted therapeutically.Significance: As PTEN-deficient prostate cancer cells proliferate in low-nutrient environments by scavenging necrotic debris and extracellular protein via macropinocytosis, blocking macropinocytosis by inhibiting AMPK, RAC1, or PI3K may have therapeutic value, particularly in necrotic tumors and in combination with therapies that cause nutrient stress. Cancer Discov; 8(7); 866-83. ©2018 AACR.See related commentary by Commisso and Debnath, p. 800This article is highlighted in the In This Issue feature, p. 781.

Genomic Deletion at 10q23 in Prostate Cancer: More Than PTEN Loss?

The PTEN gene encodes for the phosphatase and tensin homolog; it is a tumor suppressor gene that is among the most frequently inactivated genes throughout the human cancer spectrum. The most recent sequencing approaches have allowed the identification of PTEN genomic alterations, including deletion, mutation, or rearrangement in about 50% of prostate cancer (PCa) cases. It appears that mechanisms leading to PTEN inactivation are cancer-specific, comprising gene mutations, small insertions/deletions, copy number alterations (CNAs), promoter hypermethylation, and RNA interference. The examination of publicly available results from deep-sequencing studies of various cancers showed that PCa appears to be the only cancer in which PTEN is lost mostly through CNA. Instead of inactivating mutations, which are seen in other cancers, deletion of the 10q23 locus is the most common form of PTEN inactivation in PCa. By investigating the minimal deleted region at 10q23, several other genes appear to be lost simultaneously with PTEN. Expression data indicate that, like PTEN, these genes are also downregulated upon loss of 10q23. These analyses raise the possibility that 10q23 is lost upon selective pressure not only to inactivate PTEN but also to impair the expression of surrounding genes. As such, several genes from this deleted region, which represents about 500 kb, may also act as tumor suppressors in PCa, requiring further studies on their respective functions in that context.

Taming the Notch Transcriptional Regulator for Cancer Therapy

Abstract Notch signaling is a highly conserved pathway in all metazoans, which is deeply involved in the regulation of cell fate and differentiation, proliferation and migration during development. Research in the last decades has shown that the various components of the Notch signaling cascade are either upregulated or activated in human cancers. Therefore, its downregulation stands as a promising and powerful strategy for cancer therapy. Here, we discuss the recent advances in the development of small molecule inhibitors, blocking antibodies and oligonucleotides that hinder Notch activity, and their outcome in clinical trials. Although Notch was initially identified as an oncogene, later studies showed that it can also act as a tumor suppressor in certain contexts. Further complexity is added by the existence of numerous Notch family members, which exert different activities and can be differentially targeted by inhibitors, potentially accounting for contradictory data on their therapeutic efficacy. Notably, recent evidence supports the rationale for combinatorial treatments including Notch inhibitors, which appear to be more effective than single agents in fighting cancer.