Can epigenetic and inflammatory biomarkers identify clinically aggressive prostate cancer?

Biased holoenzyme assembly of protein phosphatase 2A (PP2A): From cancer to small molecules

Protein phosphatase 2A (PP2A) is a family of serine threonine phosphatases responsible for regulating protein phosphorylation, thus opposing the activity of cellular kinases. PP2A is composed of a catalytic subunit (PP2A Cα/β) and scaffolding subunit (PP2A Aα/β) and various substrate-directing B regulatory subunits. PP2A biogenesis is regulated at multiple levels. For example, the sequestration of the free catalytic subunit during the process of biogenesis avoids promiscuous phosphatase activity. Posttranslational modifications of PP2A C direct PP2A heterotrimeric formation. Additionally, PP2A functions as a haploinsufficient tumor suppressor, where attenuated PP2A enzymatic activity creates a permissive environment for oncogenic transformation. Recent work studying PP2A in cancer showed that its role in tumorigenesis is more nuanced, with some holoenzymes being tumor suppressive, while others are required for oncogenic transformation. In cancer biology, PP2A function is modulated through various mechanisms including the displacement of specific B regulatory subunits by DNA tumor viral antigens, by recurrent mutations, and through loss of carboxymethyl-sensitive heterotrimeric complexes. In aggregate, these alterations bias PP2A activity away from its tumor suppressive functions and toward oncogenic ones. From a therapeutic perspective, molecular glues and disruptors present opportunities for both the selective stabilization of tumor-suppressive holoenzymes and disruption of holoenzymes that are pro-oncogenic. Collectively, these approaches represent an attractive cancer therapy for a wide range of tumor types. This review will discuss the mechanisms by which PP2A holoenzyme formation is dysregulated in cancer and the current therapies that are aimed at biasing heterotrimer formation of PP2A for the treatment of cancer.

Roles of Key Epigenetic Regulators in the Gene Transcription and Progression of Prostate Cancer

Prostate cancer (PCa) is a top-incidence malignancy, and the second most common cause of death amongst American men and the fifth leading cause of cancer death in men around the world. Androgen receptor (AR), the key transcription factor, is critical for the progression of PCa by regulating a series of target genes by androgen stimulation. A number of co-regulators of AR, including co-activators or co-repressors, have been implicated in AR-mediated gene transcription and PCa progression. Epigenetic regulators, by modifying chromatin integrity and accessibility for transcription regulation without altering DNA sequences, influence the transcriptional activity of AR and further regulate the gene expression of AR target genes in determining cell fate, PCa progression and therapeutic response. In this review, we summarized the structural interaction of AR and epigenetic regulators including histone or DNA methylation, histone acetylation or non-coding RNA, and functional synergy in PCa progression. Importantly, epigenetic regulators have been validated as diagnostic markers and therapeutic targets. A series of epigenetic target drugs have been developed, and have demonstrated the potential to treat PCa alone or in combination with antiandrogens.

Role of miR-182/PDCD4 axis in aggressive behavior of prostate cancer in the African Americans

Background

Prostate cancer is one of the most commonly diagnosed cancers among men. African Americans (AA) are at an increased risk of developing prostate cancer compared to European Americans (EA). miRNAs play a critical role in these tumors, leading to tumor progression. In this study, we investigated the role of miR-182 in racial disparity in prostate cancer.

Results

We found significantly increased levels of miR-182 in prostate cancer tissues compared to BPH. Also, miR-182 shows increased expression in AA prostate cancer cell line and tissue samples compared to EA. We performed biochemical recurrence (BCR) - free survival time in AA and EA patients and found that high miR-182 expression had significantly shorter BCR-free survival than patients with low miR-182 expression (P = 0.031). To elucidate the role of miR-182, we knocked down miR-182 in EA (DU-145 and LNCaP) and AA (MDA-PCa-2b) cell lines and found an increase in apoptosis, arrest of the cell cycle, and inhibition of colony formation in the AA cell line to a greater extent than EA cell lines.

Conclusions

Our results showed that PDCD4 is a direct miR-182 target and its inhibition is associated with aggressiveness and high Gleason grade in prostate cancer among AA. These findings show that miR-182 is highly expressed in AA patients and miR-182 may be a target for effective therapy in AA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08723-6.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Artepillin C as an outstanding phenolic compound of Brazilian green propolis for disease treatment: A review on pharmacological aspects

Propolis is a viscous resin consisting of plant material (shoots, flowers, and plant exudates), salivary secretions and waxes produced by Apis mellifera bees. Its popular use aroused the interests of scientific research, which proved to be a potential source of various bioactive substances. The chemical composition of propolis depends on several factors, such as the different types of plant sources collected by bees, geographic origin, and the time of year in which they are produced, but it is known that phenolic represent the main bioactive constituents of propolis. Baccharis dracunculifolia DC (Asteraceae) is the most important botanical source of propolis and a native to southeastern Brazil. It is widely known as the green propolis because of its deep green color. One of its major phenolic acids is artepillin C (Art-C), a diprenyl-p-hydroxycinnamic acid derivative. This review aims to provide a comprehensive summary of the pharmacological effects of Art-C. The limited number of publications on this topic over the past two decades have been collected from databases and summarized. Numerous biological activities have been described for the Art-C, such as gastroprotective, anti-inflammatory, antimicrobial, antioxidant, antitumor. This article describes aspects of occurrence, synthesis, biological activities and pharmacokinetic approaches.

The PP2A subunit PR130 is a key regulator of cell development and oncogenic transformation

Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase. This enzyme is involved in a plethora of cellular processes, including apoptosis, autophagy, cell proliferation, and DNA repair. Remarkably, PP2A can act as a context-dependent tumor suppressor or promoter. Active PP2A complexes consist of structural (PP2A-A), regulatory (PP2A-B), and catalytic (PP2A-C) subunits. The regulatory subunits define the substrate specificity and the subcellular localization of the holoenzyme. Here we condense the increasing evidence that the PP2A B-type subunit PR130 is a critical regulator of cell identity and oncogenic transformation. We summarize knowledge on the biological functions of PR130 in normal and transformed cells, targets of the PP2A-PR130 complex, and how diverse extra- and intracellular stimuli control the expression and activity of PR130. We additionally review the impact of PP2A-PR130 on cardiac functions, neuronal processes, and anti-viral defense and how this might affect cancer development and therapy.

Computational analysis of eugenol inhibitory activity in lipoxygenase and cyclooxygenase pathways

Chronic inflammation is triggered by numerous diseases such as osteoarthritis, Crohn's disease and cancer. The control of the pro-inflammatory process can prevent, mitigate and/or inhibit the evolution of these diseases. Therefore, anti-inflammatory drugs have been studied as possible compounds to act in these diseases. This paper proposes a computational analysis of eugenol in relation to aspirin and diclofenac and analyzing the ADMET profile and interactions with COX-2 and 5-LOX enzymes, important enzymes in the signaling pathway of pro-inflammatory processes. Through the analysis of ADMET in silico, it was found that the pharmacokinetic results of eugenol are similar to NSAIDs, such as diclofenac and aspirin. Bioinformatics analysis using coupling tests showed that eugenol can bind to COX-2 and 5-LOX. These results corroborate with different findings in the literature that demonstrate anti-inflammatory activity with less gastric irritation, bleeding and ulcerogenic side effects of eugenol. The results of bioinformatics reinforce studies that try to propose eugenol as an anti-inflammatory compound that can act in the COX-2/5-LOX pathways, replacing some NSAIDs in different diseases.

Prostate cancer management: long-term beliefs, epidemic developments in the early twenty-first century and 3PM dimensional solutions

In the early twenty-first century, societies around the world are facing the paradoxal epidemic development of PCa as a non-communicable disease. PCa is the most frequently diagnosed cancer for men in several countries such as the USA. Permanently improving diagnostics and treatments in the PCa management causes an impressive divergence between, on one hand, permanently increasing numbers of diagnosed PCa cases and, on the other hand, stable or even slightly decreasing mortality rates. Still, aspects listed below are waiting for innovate solutions in the context of predictive approaches, targeted prevention and personalisation of medical care (PPPM / 3PM).A.PCa belongs to the cancer types with the highest incidence worldwide. Corresponding economic burden is enormous. Moreover, the costs of treating PCa are currently increasing more quickly than those of any other cancer. Implementing individualised patient profiles and adapted treatment algorithms would make currently too heterogeneous landscape of PCa treatment costs more transparent providing clear "road map" for the cost saving.B.PCa is a systemic multi-factorial disease. Consequently, predictive diagnostics by liquid biopsy analysis is instrumental for the disease prediction, targeted prevention and curative treatments at early stages.C.The incidence of metastasising PCa is rapidly increasing particularly in younger populations. Exemplified by trends observed in the USA, prognosis is that the annual burden will increase by over 40% in 2025. To this end, one of the evident deficits is the reactive character of medical services currently provided to populations. Innovative screening programmes might be useful to identify persons in suboptimal health conditions before the clinical onset of metastasising PCa. Strong predisposition to systemic hypoxic conditions and ischemic lesions (e.g. characteristic for individuals with Flammer syndrome phenotype) and low-grade inflammation might be indicative for specific phenotyping and genotyping in metastasising PCa screening and disease management. Predictive liquid biopsy tests for CTC enumeration and their molecular characterisation are considered to be useful for secondary prevention of metastatic disease in PCa patients.D.Particular rapidly increasing PCa incidence rates are characteristic for adolescents and young adults aged 15-40 years. Patients with early onset prostate cancer pose unique challenges; multi-factorial risks for these trends are proposed. Consequently, multi-level diagnostics including phenotyping and multi-omics are considered to be the most appropriate tool for the risk assessment, prediction and prognosis. Accumulating evidence suggests that early onset prostate cancer is a distinct phenotype from both aetiological and clinical perspectives deserving particular attention from view point of 3P medical approaches.