NF-kappa B activates prostate-specific antigen expression and is upregulated in androgen-independent prostate cancer

NSAID-encapsulated nanoparticles as a targeted therapeutic platform for modulating chronic inflammation and inhibiting cancer progression: a review

Recent advancements in nanotechnology have significantly advanced nanocarrier-mediated drug delivery systems, promoting therapeutic outcomes in mitigating chronic inflammation and cancer. Nanomaterials offer significant advantages over traditional small-molecule drugs, including a high surface-area-to-volume ratio, tunable structural features, and extended bloodstream circulation time. Chronic inflammation is a well-established mechanism for malignant initiation, progression, and metastasis, promoting the potent strategy for cancer prevention and therapy. Numerous studies revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) have the therapeutic ability to manage disease progression via amolerating angiogenesis and inducing apoptosis. However, prolonged intake of NSAIDs is often limited by adverse side-effects and systemic toxicities. The encapsulation of NSAIDs in a nanocarrier have materialized as a dynamic approach to mitigate the limitations by improving pharmacokinetics and pharmacodynamics, reducing off-target effects, and enhancing the drug stability. This review encompasses recent progress in the development of NSAID-based nanotherapeutics, focusing on pivotal mechanisms underlying nanoparticle-mediated drug delivery, such as improved tumor-specific targeting and strategies to overcome drug resistance. The ability of these nano-cargoes to accommodate anti-inflammatory strategies with advanced drug delivery platforms is critically evaluated. This review also highlights the transformative potential of NSAID-encapsulated nanoparticles as a multifaceted therapeutic venue for addressing chronic inflammation and mitigating cancer progression.

Transcriptome-wide association analysis identifies candidate susceptibility genes for prostate-specific antigen levels in men without prostate cancer

Deciphering the genetic basis of prostate-specific antigen (PSA) levels may improve their utility for prostate cancer (PCa) screening. Using genome-wide association study (GWAS) summary statistics from 95,768 PCa-free men, we conducted a transcriptome-wide association study (TWAS) to examine impacts of genetically predicted gene expression on PSA. Analyses identified 41 statistically significant (p < 0.05/12,192 = 4.10 × 10-6) associations in whole blood and 39 statistically significant (p < 0.05/13,844 = 3.61 × 10-6) associations in prostate tissue, with 18 genes associated in both tissues. Cross-tissue analyses identified 155 statistically significantly (p < 0.05/22,249 = 2.25 × 10-6) genes. Out of 173 unique PSA-associated genes across analyses, we replicated 151 (87.3%) in a TWAS of 209,318 PCa-free individuals from the Million Veteran Program. Based on conditional analyses, we found 20 genes (11 single tissue, nine cross-tissue) that were associated with PSA levels in the discovery TWAS that were not attributable to a lead variant from a GWAS. Ten of these 20 genes replicated, and two of the replicated genes had colocalization probability of >0.5: CCNA2 and HIST1H2BN. Six of the 20 identified genes are not known to impact PCa risk. Fine-mapping based on whole blood and prostate tissue revealed five protein-coding genes with evidence of causal relationships with PSA levels. Of these five genes, four exhibited evidence of colocalization and one was conditionally independent of previous GWAS findings. These results yield hypotheses that should be further explored to improve understanding of genetic factors underlying PSA levels.

Sterile inflammation via TRPM8 RNA-dependent TLR3-NF-kB/IRF3 activation promotes antitumor immunity in prostate cancer

Inflammation is a common condition of prostate tissue, whose impact on carcinogenesis is highly debated. Microbial colonization is a well-documented cause of a small percentage of prostatitis cases, but it remains unclear what underlies the majority of sterile inflammation reported. Here, androgen- independent fluctuations of PSA expression in prostate cells have lead us to identify a prominent function of the Transient Receptor Potential Cation Channel Subfamily M Member 8 (TRPM8) gene in sterile inflammation. Prostate cells secret TRPM8 RNA into extracellular vesicles (EVs), which primes TLR3/NF-kB-mediated inflammatory signaling after EV endocytosis by epithelial cancer cells. Furthermore, prostate cancer xenografts expressing a translation-defective form of TRPM8 RNA contain less collagen type I in the extracellular matrix, significantly more infiltrating NK cells, and larger necrotic areas as compared to control xenografts. These findings imply sustained, androgen-independent expression of TRPM8 constitutes as a promoter of anticancer innate immunity, which may constitute a clinically relevant condition affecting prostate cancer prognosis.

Targeting PKD2 aggravates ferritinophagy-mediated ferroptosis via promoting autophagosome-lysosome fusion and enhances efficacy of carboplatin in lung adenocarcinoma

Ferroptosis is an iron-dependent cell death and affects efficacies of multiple antitumor regimens, showing a great potential in cancer therapy. Protein kinase D2 (PKD2) plays a crucial role in regulating necrosis and apoptosis. However, the relationship of PKD2 and ferroptosis is still elusive. In this study, we mainly analyzed the roles of PKD2 on ferroptosis and chemotherapy in lung adenocarcinoma (LUAD). We found PKD2 was highly expressed in LUAD and silencing PKD2 could promote erastin-induced reactive oxygen species (ROS), malondialdehyde (MDA) accumulation, intracellular iron content and LUAD cells death. Mechanistically, augmenting PKD2 could prevent autophagic degradation of ferritin, which could be impaired by bafilomycin A1. We further found that PKD2 overexpression would promote LC3B-II, p62/SQSTM1 accumulation and block autophagosome-lysosome fusion in a TFEB-independent manner, which could be impaired by bafilomycin A1. Bafilomycin A1 stimulation could weaken ferroptosis promotion by PKD2 abrogation. Silencing ferritin heavy chain-1 (FTH1) could reverse the resistance to ferroptosis by PKD2 overexpression. Additionally, in vitro and vivo experiments validated PKD2 promoted proliferation, migration and invasion of LUAD cells. PKD2 knockdown or pharmacological inhibition by CRT0066101 could enhance efficacy of carboplatin in LUAD via ferroptosis and apoptosis. Collectively, our study revealed that abrogation of PKD2 could aggravate ferritinophagy-mediated ferroptosis by promoting autophagosome-lysosome fusion and enhance efficacy of carboplatin in LUAD. Targeting PKD2 to induce ferroptosis may be a promising strategy for LUAD therapy.

Transcriptome-Wide Association Analysis Identifies Novel Candidate Susceptibility Genes for Prostate-Specific Antigen Levels in Men Without Prostate Cancer

Deciphering the genetic basis of prostate-specific antigen (PSA) levels may improve their utility to screen for prostate cancer (PCa). We thus conducted a transcriptome-wide association study (TWAS) of PSA levels using genome-wide summary statistics from 95,768 PCa-free men, the MetaXcan framework, and gene prediction models trained in Genotype-Tissue Expression (GTEx) project data. Tissue-specific analyses identified 41 statistically significant (p < 0.05/12,192 = 4.10e-6) associations in whole blood and 39 statistically significant (p < 0.05/13,844 = 3.61e-6) associations in prostate tissue, with 18 genes associated in both tissues. Cross-tissue analyses that combined associations across 45 tissues identified 155 genes that were statistically significantly (p < 0.05/22,249 = 2.25e-6) associated with PSA levels. Based on conditional analyses that assessed whether TWAS associations were attributable to a lead GWAS variant, we found 20 novel genes (11 single-tissue, 9 cross-tissue) that were associated with PSA levels in the TWAS. Of these novel genes, five showed evidence of colocalization (colocalization probability > 0.5): EXOSC9, CCNA2, HIST1H2BN, RP11-182L21.6, and RP11-327J17.2. Six of the 20 novel genes are not known to impact PCa risk. These findings yield new hypotheses for genetic factors underlying PSA levels that should be further explored toward improving our understanding of PSA biology.

Androgen Receptor Upregulates Mucosa-Associated Lymphoid Tissue 1 to Induce NF-κB Activity via Androgen-Dependent and -Independent Pathways in Prostate Carcinoma Cells

The androgen-dependent or -independent pathways are regarded as primary therapeutic targets for the neoplasm of the prostate. Mucosa-associated lymphoid tissue 1 (MALT1) acting as a paracaspase in the regulation of nuclear factor κB (NF-κB) signal transduction plays a central role in inflammation and oncogenesis in cancers. This study confirmed the potential linkages between androgen and NF-κB activation by inducing MALT1 in the androgen receptor-full length (ARFL)-positive LNCaP and 22Rv1 prostate cancer cells. Although androgen did not stimulate MALT1 expression in AR-null or ectopic ARFL-overexpressed PC-3 cells, the ectopic overexpression of the AR splicing variant 7 (ARv7) upregulated MALT1 to activate NF-κB activities in 22Rv1 and PC-3 cells. Since the nuclear translocation of p50 and p65 was facilitated by ARv7 to motivate NF-κB activity, the expressions of MALT1, prostate-specific antigen (PSA), and N-myc downstream regulated 1 (NDRG1) were therefore induced in ectopic ARv7-overexpressed prostate cancer cells. Ectopic ARv7 overexpression not only enhanced 22Rv1 or PC-3 cell growth and invasion in vitro but also the tumor growth of PC-3 cells in vivo. These results indicate that an androgen receptor induces MALT1 expression androgen-dependently and -independently in ARFL- or ARv7-overexpressed prostate cancer cells, suggesting a novel ARv7/MALT1/NF-κB-signaling pathway may exist in the cells of prostate cancer.

Antagonistic Functions of Androgen Receptor and NF-κB in Prostate Cancer-Experimental and Computational Analyses

Prostate cancer is very frequent and is, in many countries, the third-leading cause of cancer related death in men. While early diagnosis and treatment by surgical removal is often curative, metastasizing prostate cancer has a very bad prognosis. Based on the androgen-dependence of prostate epithelial cells, the standard treatment is blockade of the androgen receptor (AR). However, nearly all patients suffer from a tumor relapse as the metastasizing cells become AR-independent. In our study we show a counter-regulatory link between AR and NF-κB both in human cells and in mouse models of prostate cancer, implying that inhibition of AR signaling results in induction of NF-κB-dependent inflammatory pathways, which may even foster the survival of metastasizing cells. This could be shown by reporter gene assays, DNA-binding measurements, and immune-fluorescence microscopy, and furthermore by a whole set of computational methods using a variety of datasets. Interestingly, loss of PTEN, a frequent genetic alteration in prostate cancer, also causes an upregulation of NF-κB and inflammatory activity. Finally, we present a mathematical model of a dynamic network between AR, NF-κB/IκB, PI3K/PTEN, and the oncogene c-Myc, which indicates that AR blockade may upregulate c-Myc together with NF-κB, and that combined anti-AR/anti-NF-κB and anti-PI3K treatment might be beneficial.

Patchouli alcohol inhibits GPBAR1-mediated cell proliferation, apoptosis, migration, and invasion in prostate cancer

Background

G protein-coupled bile acid receptor 1 (GPBAR1) is a G protein-coupled receptor for bile acids, which is widely expressed in many human tissues. Patchouli alcohol (PA) has been shown to have an anti-cancer effect, including in prostate cancer (PCa). This study sought to confirm the regulatory mechanism of GPBAR1 in the anti-cancer activity of PA in PCa.

Methods

The SwissTargetPrediction website (Pro >0) was used to predict the target of PA. The UALCAN and The Cancer Genome Atlas-Prostate cohort was used to examine the differentially expressed genes and PCa recurrence. A gene set enrichment analysis (GSEA) was conducted to analyze the relationship between the expression of GPBAR1 and PCa proliferation, migration, and invasion. Cell proliferation, migration, and invasion were assessed by colony formation, 5-Ethynyl-2'-deoxyuridine staining, cell scratch assays, and Transwell invasion assays, respectively. A xenograft animal model was established to assess the effect of PA on tumor growth in vivo. GPBAR1 protein and apoptosis related protein expression was measured by western blot.

Results

GPBAR1 was a PA target predicted by the SwissTargetPrediction website. PA inhibited the expression of GPBAR1 in PCa cells in a time- and dose-dependent manner. The abnormal expression of GPBAR1 was related to cell proliferation, migration, and invasion. Additionally, GPBAR1 overexpression promoted the cell proliferation, migration, and invasion, and inhibited the apoptosis of PCa cells. GPBAR1 silencing inhibited the cell proliferation, migration, and invasion, and promoted the apoptosis of PCa cells. High expressions of GPBAR1 suppressed tumor growth in tumor-bearing mice. Further, GPBAR1 promoted the activation of nuclear factor kappa B (NF-κB) signaling, and PA regulated the malignant phenotypes of PCa cells via the NF-κB signaling pathway mediated by GPBAR1.

Conclusions

GPBAR1 is a promising drug target of PA, and was shown to regulate the proliferation, apoptosis, migration, and invasion of PCa cells through GPBAR1/NF-κB inhibition.

NSAIDs and Cancer Resolution: New Paradigms beyond Cyclooxygenase

Acute inflammation or resolved inflammation is an adaptive host defense mechanism and is self-limiting, which returns the body to a state of homeostasis. However, unresolved, uncontrolled, or chronic inflammation may lead to various maladies, including cancer. Important evidence that links inflammation and cancer is that nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, reduce the risk and mortality from many cancers. The fact that NSAIDs inhibit the eicosanoid pathway prompted mechanistic drug developmental work focusing on cyclooxygenase (COX) and its products. The increased prostaglandin E2 levels and the overexpression of COX-2 in the colon and many other cancers provided the rationale for clinical trials with COX-2 inhibitors for cancer prevention or treatment. However, NSAIDs do not require the presence of COX-2 to prevent cancer. In this review, we highlight the effects of NSAIDs and selective COX-2 inhibitors (COXIBs) on targets beyond COX-2 that have shown to be important against many cancers. Finally, we hone in on specialized pro-resolving mediators (SPMs) that are biosynthesized locally and, in a time, -dependent manner to promote the resolution of inflammation and subsequent tissue healing. Different classes of SPMs are reviewed, highlighting aspirin's potential in triggering the production of these resolution-promoting mediators (resolvins, lipoxins, protectins, and maresins), which show promise in inhibiting cancer growth and metastasis.

The Antitumor Effect of Caffeic Acid Phenethyl Ester by Downregulating Mucosa-Associated Lymphoid Tissue 1 via AR/p53/NF-κB Signaling in Prostate Carcinoma Cells

Caffeic acid phenethyl ester (CAPE), a honeybee propolis-derived bioactive ingredient, has not been extensively elucidated regarding its effect on prostate cancer and associated mechanisms. The mucosa-associated lymphoid tissue 1 gene (MALT1) modulates NF-κB signal transduction in lymphoma and non-lymphoma cells. We investigated the functions and regulatory mechanisms of CAPE in relation to MALT1 in prostate carcinoma cells. In p53- and androgen receptor (AR)-positive prostate carcinoma cells, CAPE downregulated AR and MALT1 expression but enhanced that of p53, thus decreasing androgen-induced activation of MALT1 and prostate-specific antigen expressions. p53 downregulated the expression of MALT in prostate carcinoma cells through the putative consensus and nonconsensus p53 response elements. CAPE downregulated MALT1 expression and thus inhibited NF-κB activity in p53- and AR-negative prostate carcinoma PC-3 cells, eventually reducing cell proliferation, invasion, and tumor growth in vitro and in vivo. CAPE induced the ERK/JNK/p38/AMPKα1/2 signaling pathways; however, pretreatment with the corresponding inhibitors of MAPK or AMPK1/2 did not inhibit the CAPE effect on MALT1 blocking in PC-3 cells. Our findings verify that CAPE is an effective antitumor agent for human androgen-dependent and -independent prostate carcinoma cells in vitro and in vivo through the inhibition of MALT1 expression via the AR/p53/NF-κB signaling pathways.

Early mRNA Expression of Neuroendocrine Differentiation Signals Predicts Recurrence After Radical Prostatectomy: A Transcriptomic Analysis

BACKGROUND

Neuroendocrine differentiation (NED) of prostate cancer (PC) is a process that often occurs under evolutionary pressure from pharmacologic blockade of androgen receptor signaling at advanced stages of the disease. Identifying a subset of early PC that has a higher likelihood to evolve into this entity is key for developing therapeutic strategies that could more effectively target this phenotype. This study aimed to assess the prognostic relevance of mRNA expression of major players involved in NED of primary prostate tumors.

METHODS

RNA sequencing data from 122 patients with localized PC were analyzed. Transcript levels of key genes involved in NED, with a focus on endothelin axis and nuclear factor kappa B (NF-κB), were assessed and were correlated with time to prostate specific antigen (PSA) recurrence. Copy number alteration of tumor suppressor genes and gene expression of additional signals hallmarking NED was compared between altered and unaltered groups, including lineage determining transcription factors, transcriptional repressors, cell cycle and epigenetic regulators.

RESULTS

The presence of altered mRNA expression using a z-score threshold of 2 in NFKB1, RELA, EDN1, EDNRA, and EDNRB genes was associated with a higher Gleason score (P < 0.001) and a shorter time to biochemical recurrence (BCR) (P = 0.029). There was a significant direct correlation between NFKB1 and RELA (P < 0.001), NFKB1 and EDNRA (P < 0.001), NFKB1 and EDNRB (P < 0.001), EDNRA and EDNRB expression (P < 0.001). ASCL1 (q < 0.001), ONECUT2 (q < 0.001), DLL3 (q = 0.019), AURKA (q = 0.013), AURKB (q = 0.014), PLK1 (q < 0.001), and EZH2 (q < 0.001) were enriched in patients with tumors harboring alterations in endothelin axis and NF-κB subunit genes whereas REST was downregulated (q < 0.001).

CONCLUSIONS

This analysis suggests that altered mRNA expression of NF-κB and endothelin axis genes in early PC is not only a harbinger of a more aggressive clinical course but is also associated with aberrant gene expression of several transcription factors, transcriptional repressors, cell cycle and epigenetic regulators that are directly involved in NED, in line with their biological roles. This may have implications for closer follow-up and potential use of targeted therapeutic approaches postoperatively in the adjuvant setting to improve outcomes of these patients.

Radioresistance in Prostate Cancer: Focus on the Interplay between NF-κB and SOD

Prostate cancer occurs frequently in men and can often lead to death. Many cancers, including prostate cancer, can be initiated by oxidative insult caused by free radicals and reactive oxygen species. The superoxide dismutase family removes the oxygen-derived reactive oxygen species, and increased superoxide dismutase activity can often be protective against prostate cancer. Prostate cancer can be treated in a variety of ways, including surgery, androgen deprivation therapy, radiation therapy, and chemotherapy. The clinical trajectory of prostate cancer varies from patient to patient, but more aggressive tumors often tend to be radioresistant. This is often due to the free-radical and reactive-oxygen-species-neutralizing effects of the superoxide dismutase family. Superoxide dismutase 2, which is especially important in this regard, can be induced by the NF-κB pathway, which is an important mechanism in radioresistance. This information has enabled the development of interventions that manipulate the NF-κB mechanism to treat prostate cancer.

Effect of estrogen-active compounds on the expression of RACK1 and immunological implications

We previously demonstrated the existence of a balance among steroid hormones, i.e. glucocorticoids and androgens, in RACK1 (receptor for activated C kinase 1) expression and innate immunity activation, which may offer the opportunity to use RACK1 expression as marker to evaluate immunotoxicity of hormone-active substances. Because of the existence of close interconnections between the different steroid hormone receptors with overlapping ligand specificities and signaling pathways, in this study, we wanted to investigate a possible effect of estrogenic active compounds, namely 17β-estradiol, diethylstilbestrol, and zearalenone, on RACK-1 expression and innate immune responses using THP-1 cells as experimental model. All compounds increased RACK1 transcriptional activity as evaluated by reporter luciferase activity, mRNA expression as assessed by real time-PCR and protein expression by western blot analysis, which paralleled an increase in LPS-induced IL-8, TNF-α production, and CD86 expression, which we previously demonstrated to be dependent on RACK1/PKCβ activation. As the induction of RACK1 expression can be blocked by the antagonist G15, induced by the agonist G1 and by the non-cell permeable 17β-estradiol conjugated with BSA, a role of GPER (previously named GPR30) activation in estrogen-induced RACK1 expression could be demonstrated. In addition, a role of androgen receptor (AR) in RACK1 transcription was also demonstrated by the ability of flutamide, a nonsteroidal antiandrogen, to completely prevent diethylstilbestrol-induced RACK1 transcriptional activity and protein expression. Altogether, our data suggest that RACK1 may represent an interesting target of steroid-active compounds, and its evaluation may offer the opportunity to screen the immunotoxic potential of hormone-active substances.

NF-κB signaling promotes castration-resistant prostate cancer initiation and progression

Prostate Cancer (PCa) is the second leading cause of cancer-related death in men. Adenocarcinoma of the prostate is primarily composed of Androgen Receptor-positive (AR⁺) luminal cells that require AR transcriptional activity for survival and proliferation. As a consequence, androgen deprivation and anti-androgens are used to treat PCa patients whose disease progresses following attempted surgical or radiation interventions. Unfortunately, patients with advanced PCa can develop incurable castration-resistant PCa (CRPCa) due to mutated, variant, or overexpressed AR. Conversely, low or no AR accumulation or activity can also underlie castration resistance. Whether CRPCa is due to aberrant AR activity or AR independence, NF-κB signaling is also implicated in the initiation and maintenance of CRPCa and, thus, the NF-κB pathway may be a promising alternative therapeutic target. In this review, we present evidence that NF-κB signaling promotes CRPCa initiation and progression, describe the dichotomic role of NF-κB in the regulation of AR expression and activity and outline studies that explore NF-κB inhibitors as PCa therapies.

The prognostic impact of tumour NSD2 expression in advanced prostate cancer

Purpose: To assess the prognostic significance of the nuclear receptor binding SET protein 2 (NSD2), a co-activator of the NFkB-pathway, on tumour progression in patients with advanced prostate cancer (PCa).Methods: We retrospectively assessed NSD2 expression in 53 patients with metastatic and castration-resistant PCa. Immunohistochemical staining for NSD2 was carried out on specimen obtained from palliative resection of the prostate. Univariable and multivariable analyses were performed to assess the association between NSD2 expression and PCa progression.Results: Of the 53 patients, 41 had castration-resistant PCa and 48 men had metastases at time of tissue acquisition. NSD2 expression was increased in tumour specimen from 42 patients (79.2%). In univariable Cox regression analyses, NSD2 expression was associated with PSA progression, progression on imaging and overall survival (p = 0.04, respectively). In multivariable analyses, NSD2 expression did not retain its association with these endpoints.Conclusions: NSD2 expression is abnormal in almost 80% of patients with advanced PCa. Expression levels of this epigenetic regulator are easily detected by immunohistochemistry while this biomarker exhibited prognostic value for PCa progression and death in univariable analysis. Further studies on NSD2 involvement in PCa proliferation, progression, metastasis and resistance mechanisms are needed.

Lajis N, Abas F, Othman I, Naidu R. Mechanism of Anti-Cancer Activity of Curcumin on Androgen-Dependent and Androgen-Independent Prostate Cancer

Prostate cancer (PCa) is a heterogeneous disease and ranked as the second leading cause of cancer-related deaths in males worldwide. The global burden of PCa keeps rising regardless of the emerging cutting-edge technologies for treatment and drug designation. There are a number of treatment options which are effectively treating localised and androgen-dependent PCa (ADPC) through hormonal and surgery treatments. However, over time, these cancerous cells progress to androgen-independent PCa (AIPC) which continuously grow despite hormone depletion. At this particular stage, androgen depletion therapy (ADT) is no longer effective as these cancerous cells are rendered hormone-insensitive and capable of growing in the absence of androgen. AIPC is a lethal type of disease which leads to poor prognosis and is a major contributor to PCa death rates. A natural product-derived compound, curcumin has been identified as a pleiotropic compound which capable of influencing and modulating a diverse range of molecular targets and signalling pathways in order to exhibit its medicinal properties. Due to such multi-targeted behaviour, its benefits are paramount in combating a wide range of diseases including inflammation and cancer disease. Curcumin exhibits anti-cancer properties by suppressing cancer cells growth and survival, inflammation, invasion, cell proliferation as well as possesses the ability to induce apoptosis in malignant cells. In this review, we investigate the mechanism of curcumin by modulating multiple signalling pathways such as androgen receptor (AR) signalling, activating protein-1 (AP-1), phosphatidylinositol 3-kinases/the serine/threonine kinase (PI3K/Akt/mTOR), wingless (Wnt)/ß-catenin signalling, and molecular targets including nuclear factor kappa-B (NF-κB), B-cell lymphoma 2 (Bcl-2) and cyclin D1 which are implicated in the development and progression of both types of PCa, ADPC and AIPC. In addition, the role of microRNAs and clinical trials on the anti-cancer effects of curcumin in PCa patients were also reviewed.

Endocrinotherapy resistance of prostate and breast cancer: Importance of the NF‑κB pathway (Review)

Prostate cancer (PCa) and breast cancer (BCa) are two common sex hormone‑related cancer types with high rates of morbidity, and are leading causes of cancer death globally in men and women, respectively. The biological function of androgen or estrogen is a key factor for PCa or BCa tumorigenesis, respectively. Nevertheless, after hormone deprivation therapy, the majority of patients ultimately develop hormone‑independent malignancies that are resistant to endocrinotherapy. It is widely recognized, therefore, that understanding of the mechanisms underlying the process from hormone dependence towards hormone independence is critical to discover molecular targets for the control of advanced PCa and BCa. This review aimed to dissect the important mechanisms involved in the therapeutic resistance of PCa and BCa. It was concluded that activation of the NF‑κB pathway is an important common mechanism for metastasis and therapeutic resistance of the two types of cancer; in particular, the RelB‑activated noncanonical NF‑κB pathway appears to be able to lengthen and strengthen NF‑κB activity, which has been a focus of recent investigations.

The impact of Catechol-O-methyl transferase knockdown on the cell proliferation of hormone-responsive cancers

Estrogen (E2) plays a central role in the development and progression of hormone-responsive cancers. Estrogen metabolites exhibit either stimulatory or inhibitory roles on breast and prostate cells. The catechol metabolite 4-hydroxyestradiol (4-OHE2) enhances cell proliferation, while 2-methoxyestradiol (2 ME) possesses anticancer activity. The major metabolizing enzyme responsible for detoxifying the deleterious metabolite 4-OHE2 and forming the anticancer metabolite 2 ME is Catechol-O-Methyl Transferase (COMT). The current work investigated the relationship between the expression level of COMT and the cell proliferation of hormone-responsive cancers. The results showed that COMT silencing enhanced the cell proliferation of ER-α positive cancer cells MCF-7 and PC-3 but not the cells that lack ER-α expression as MDA-MB231 and DU-145. The data generated from our study provides a better understanding of the effect of COMT on critical signaling pathways involved in the development and progression of breast cancer (BC) and prostate cancer (PC) including ER-α, p21^cip1, p27^kip1, NF-κB (P65) and CYP19A1. These findings suggest that COMT enzyme plays a tumor suppressor role in hormone receptor-positive tumors which opens the door for future studies to validate COMT expression as a novel biomarker for the prediction of cancer aggressiveness and treatment efficacy.

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.

Oncogenic functions of protein kinase D2 and D3 in regulating multiple cancer-related pathways in breast cancer

Protein Kinase D (PKD) family contains PKD1, PKD2, and PKD3 in human. Compared to consistent tumor-suppressive functions of PKD1 in breast cancer, how PKD2/3 functions in breast cancer are not fully understood. In the current study, we found that PKD2 and PKD3 but not PKD1 were preferentially overexpressed in breast cancer and involved in regulating cell proliferation and metastasis. Integrated phosphoproteome, transcriptome, and interactome showed that PKD2 was associated with multiple cancer-related pathways, including adherent junction, regulation of actin cytoskeleton, and cell cycle-related pathways. ELAVL1 was identified as a common hub-node in networks of PKD2/3-regulated phosphoproteins and genes. Silencing ELAVL1 inhibited breast cancer growth in vitro and in vivo. Direct interaction between ELAVL1 and PKD2 or PKD3 was demonstrated. Suppression of PKD2 led to ELAVL1 translocation from the cytoplasm to the nucleus without significant affecting ELAVL1 expression. Taken together, we characterized the oncogenic functions of PKD2/3 in breast cancer and their association with cancer-related pathways, which shed lights on the oncogenic roles and mechanisms of PKDs in breast cancer.

Targeting Crosstalk between Nrf-2, NF-κB and Androgen Receptor Signaling in Prostate Cancer

Oxidative stress, inflammation and androgen receptor (AR) signaling play a pivotal role in the initiation, development and progression of prostate cancer (PCa). Numerous papers in the literature have documented the interconnection between oxidative stress and inflammation; and how antioxidants can combat the inflammation. It has been shown in the literature that both oxidative stress and inflammation regulate AR, the key receptor involved in the transition of PCa to castration resistant prostate cancer (CRPC). In this review, we discuss about the importance of targeting Nrf-2-antioxidant signaling, NF-κB inflammatory response and AR signaling in PCa. Finally, we discuss about the crosstalk between these three critical pathways as well as how the anti-inflammatory antioxidant phytochemicals like sulforaphane (SFN) and curcumin (CUR), which can also target AR, can be ideal candidates in the chemoprevention of PCa.

Immunhistochemical analysis of Nuclear Factor Kappa Beta expression in etiopathogenesis of ovarian tumors1

PURPOSE

To investigate the place of the transcription factor nuclear kappa B (NF-kB), which is a marker of chronic inflammation, in the etiology of the ovarian carcinoma.

METHODS

NFkB analysis with the immunohistochemical method has been performed. To evaluate immunohistochemical NF-kB expression in the ovarian tissue, the H-score method. H-score = ∑ Pi (i+1), where ''Pi'' is the percentage of stained cells in each intensity category (0-100%) and ''i'' is the intensity indicating weak (i=1), moderate (i=2) or strong staining (i=3).

RESULTS

It has been seen that, the mean H score is statistically significantly higher in the patient group with serous and musinous adenocarcinoma diagnosis than the two other patient groups (p<0.005).

CONCLUSIONS

Factor nuclear kappa B is an important mediator that acts in the chronic inflammation. The highest expression rates are determined by the immunohistochemical method in the ovarian cancer group.

The effect of mast cells on the biological characteristics of prostate cancer cells

Aim of the study

To investigate the effects of mast cells on the proliferation, invasion, and metastasis of prostate cancer cells.

Material and methods

The mast cell P815 and prostate cancer LNCaP cells were chosen using a Transwell chamber to construct a two-cell cocultured in vitro model to observe the migration of mast cells to prostate cancer cells.

Results

In the migration experiment, the migration rate of mast cells from the experimental group (%) was 10.167 ±0.833, the mast cell migration rate (%) of the control group was 0.833 ±0.208, and the difference was statistically significant (p < 0.05). The MTT test showed that the OD value of cells in each group over time increased gradually, and 24 h after LNCaP cells were cocultured with different concentrations of mast cells, the OD value was significantly higher than that of the control group (p < 0.05). QRT-PCR and western blot results showed that, compared with the control group, E-cad expression from the experimental group was significantly weakened; N-cad and vimentin expression increased (p < 0.05), and c-kit and SCF expression from experimental group were significantly higher than that of the control group (p < 0.05). After the addition of c-kit neutralising antibodies, compared with the control group, the mast cell migration rate of experimental group decreased significantly and prostate cancer cell proliferation significantly decreased (p < 0.05).

Conclusions

Mast cells could promote the proliferation of prostate cancer cells and the occurrence of epithelial mesenchymal transition (EMT), which could promote the invasion and metastasis of prostate cancer cells.

NF-κB p50 activation associated with immune dysregulation confers poorer survival for diffuse large B-cell lymphoma patients with wild-type p53

Dysregulated NF-κB signaling is critical for lymphomagenesis, however, the expression and clinical relevance of NF-κB subunit p50 in diffuse large B-cell lymphoma have not been evaluated. In this study, we analyzed the prognostic significance and gene expression signatures of p50 nuclear expression as a surrogate for p50 activation in 465 patients with de novo diffuse large B-cell lymphoma. We found that p50+ nuclear expression, observed in 34.6% of diffuse large B-cell lymphoma, predominantly composed of activated B-cell-like subtype, was an independent adverse prognostic factor in patients with activated B-cell-like diffuse large B-cell lymphoma. It was also an adverse prognostic factor in patients with wild-type TP53 independent of the activated B-cell-like and germinal center B-cell-like subtypes, even though p50 activation correlated with significantly lower levels of Myc, PI3K, phospho-AKT, and CXCR4 expression and less frequent BCL2 translocations. In contrast, in germinal center B-cell-like diffuse large B-cell lymphoma patients with TP53 mutations, p50+ nuclear expression correlated with significantly better clinical outcomes, and decreased p53, Bcl-2, and Myc expression. Gene expression profiling revealed multiple signaling pathways potentially upstream the p50 activation through either canonical or noncanonical NF-κB pathways, and suggested that immune suppression, including that by the immune checkpoint TIM-3 and that through leukocyte immunoglobulin-like receptors, but not antiapoptosis and proliferation, may underlie the observed poorer survival rates associated with p50+ nuclear expression in diffuse large B-cell lymphoma. In conclusion, these data show that p50 is important as a unique mechanism of R-CHOP-resistance in activated B-cell-like diffuse large B-cell lymphoma and in patients without TP53 mutations. The results also provide insights into the regulation and function of p50 in diffuse large B-cell lymphoma and its cross talk with the p53 pathway with important therapeutic implications.

Protein kinase D signaling in cancer: A friend or foe?

Protein kinase D is a family of evolutionarily conserved serine/threonine kinases that belongs to the Ca⁺⁺/Calmodulin-dependent kinase superfamily. Signal transduction pathways mediated by PKD can be triggered by a variety of stimuli including G protein-coupled receptor agonists, growth factors, hormones, and cellular stresses. The regulatory mechanisms and physiological roles of PKD have been well documented including cell proliferation, survival, migration, angiogenesis, regulation of gene expression, and protein/membrane trafficking. However, its precise roles in disease progression, especially in cancer, remain elusive. A plethora of studies documented the cell- and tissue-specific expressions and functions of PKD in various cancer-associated biological processes, while the causes of the differential effects of PKD have not been thoroughly investigated. In this review, we have discussed the structural-functional properties, activation mechanisms, signaling pathways and physiological functions of PKD in the context of human cancer. Additionally, we have provided a comprehensive review of the reported tumor promoting or tumor suppressive functions of PKD in several major cancer types and discussed the discrepancies that have been raised on PKD as a major regulator of malignant transformation.

Betulinic Acid-Mediated Apoptosis in Human Prostate Cancer Cells Involves p53 and Nuclear Factor-Kappa B (NF-κB) Pathways

Defects in p53 and nuclear factor-kappa B (NF-κB) signaling pathways are frequently observed in the initiation and development of various human malignancies, including prostate cancer. Clinical studies demonstrate higher expression of NF-κB/p65/RelA, NF-κB/p50/RelB, and cRel as well as downregulation of the p53 network in primary prostate cancer specimens and in metastatic tumors. Betulinic acid (BA), is a triterpenoid that has been reported to be an effective inducer of apoptosis through modification of several signaling pathways. Our objective was to investigate the pathways involved in BA-induced apoptosis in human prostate cancer cells. We employed the androgen-responsive LNCaP cells harboring wild-type p53, and androgen-refractory DU145 cells possessing mutated p53 with high constitutive NF-κB activity. Inhibition of cell survival by BA at 10 and 20 µM concentrations occurred as a result of alteration in Bax/Bcl-2 ratio in both cell lines that led to an increased cytochrome C release, caspase activation and poly(ADP)ribose polymerase (PARP) cleavage, leading to apoptosis. BA treatment resulted in stabilization of p53 through increase in phosphorylation at Ser15 in LNCaP cells, but not in DU145 cells, and induction of cyclin kinase inhibitor p21/Waf1 in both cell types. Furthermore, treatment of both prostate cancer cells with BA decreased the phosphorylation of IκB kinase (IKK)α and I-kappa-B-alpha (IκBα) inhibiting the nuclear location of NF-κB/p65 causing cytosolic accumulation and resulting in its decreased nuclear binding. We demonstrate that BA may induce apoptosis by stabilizing p53 and downregulating NF-κB pathway in human prostate cancer cells, irrespective of the androgen association, and therefore can potentially be developed as a molecule of interest in cancer chemoprevention.

Dissecting major signaling pathways in prostate cancer development and progression: Mechanisms and novel therapeutic targets

Prostate cancer (PCa) is the most frequently diagnosed non-cutaneous malignancy and leading cause of cancer mortality in men. At the initial stages, prostate cancer is dependent upon androgens for their growth and hence effectively combated by androgen deprivation therapy (ADT). However, most patients eventually recur with an androgen deprivation-resistant phenotype, referred to as castration-resistant prostate cancer (CRPC), a more aggressive form for which there is no effective therapy presently available. The current review is an attempt to cover and establish an understanding of some major signaling pathways implicated in prostate cancer development and castration-resistance, besides addressing therapeutic strategies that targets the key signaling mechanisms.

Leucine Zipper Down-regulated in Cancer-1 (LDOC1) interacts with Guanine nucleotide binding protein-like 3-like (GNL3L) to modulate Nuclear Factor-kappa B (NF-κB) signaling during cell proliferation

Guanine nucleotide binding protein-like 3-like (GNL3L) is an evolutionarily conserved putative nucleolar GTPase belonging to the HSR1-MMR1 family. In the present study, using protein-protein interaction assays, we show that Leucine Zipper Down-regulated in Cancer-1 (LDOC1) is a novel interacting partner of GNL3L. Furthermore, our results reveal that ectopic expression of LDOC1 destabilizes endogenous GNL3L levels and down modulates GNL3L-induced cell proliferation, in contrast, the knockdown of LDOC1 potentiates cell proliferation upon GNL3L expression. Interestingly, GNL3L upregulates NF-κB dependent transcriptional activity by modulating the expression of NF-κB subunit p65, which is reversed upon co-expression of LDOC1 with GNL3L. GNL3L also potentiates TNF-α mediated NF-κB activity. In addition, anti-apoptotic function of GNL3L is impaired upon p65 knockdown, suggesting its critical role in GNL3L mediated cell proliferation/survival. An inverse correlation of GNL3L and LDOC1 expression profiles in various tumor tissues from BioXpress database indicate their critical role in cancer. Collectively, our data provides evidence that GNL3L-LDOC1 interplay regulates cell proliferation through the modulation of NF-κB pathway during tumorigenesis.

Novel Gene Expression Signature Predictive of Clinical Recurrence After Radical Prostatectomy in Early Stage Prostate Cancer Patients

BACKGROUND

Current clinical tools have limited accuracy in differentiating patients with localized prostate cancer who are at risk of recurrence from patients with indolent disease. We aimed to identify a gene expression signature that jointly with clinical variables could improve upon the prediction of clinical recurrence after RP for patients with stage T2 PCa.

METHODS

The study population includes consented patients who underwent a radical retropubic prostatectomy (RP) and bilateral pelvic lymph node dissection at the University of Southern California in the PSA-era (1988-2008). We used a nested case-control study of 187 organ-confined patients (pT2N0M0): 154 with no recurrence ("controls") and 33 with clinical recurrence ("cases"). RNA was obtained from laser capture microdissected malignant glands representative of the overall Gleason score of each patient. Whole genome gene expression profiles (29,000 transcripts) were obtained using the Whole Genome DASL HT platform (Illumina, Inc). A gene expression signature of PCa clinical recurrence was identified using stability selection with elastic net regularized logistic regression. Three existing datasets generated with the Affymetrix Human Exon 1.0ST array were used for validation: Mayo Clinic (MC, n = 545), Memorial Sloan Kettering Cancer Center (SKCC, n = 150), and Erasmus Medical Center (EMC, n = 48). The areas under the ROC curve (AUCs) were obtained using repeated fivefold cross-validation.

RESULTS

A 28-gene expression signature was identified that jointly with key clinical variables (age, Gleason score, pre-operative PSA level, and operation year) was predictive of clinical recurrence (AUC of clinical variables only was 0.67, AUC of clinical variables, and 28-gene signature was 0.99). The AUC of this gene signature fitted in each of the external datasets jointly with clinical variables was 0.75 (0.72-0.77) (MC), 0.90 (0.86-0.94) (MSKCC), and 0.82 (0.74-0.91) (EMC), whereas the AUC for clinical variables only in each dataset was 0.72 (0.70-0.74), 0.86 (0.82-0.91), and 0.76 (0.67-0.85), respectively.

CONCLUSIONS

We report a novel gene-expression based classifier identified using agnostic approaches from whole genome expression profiles that can improve upon the accuracy of clinical indicators to stratify early stage localized patients at risk of clinical recurrence after RP. Prostate 76:1239-1256, 2016. © 2016 Wiley Periodicals, Inc.

microRNA-372 Suppresses Migration and Invasion by Targeting p65 in Human Prostate Cancer Cells

Prostate cancer (PCa) is one of the most prevalent malignant tumors. microRNAs (miRNAs) play an important role in cancer initiation, progression, and metastasis, and their roles in PCa are becoming more apparent. In this study, we found that microRNA-372 (miR-372) is downregulated in human PCa and inhibits the proliferation activity, migration, and invasion of DU145 cells. Subsequently, p65 is confirmed as a target of miR-372, and knockdown of p65 expression similarly resulted in decreased proliferation activity, migration, and invasion. CDK8, MMP-9, and prostate-specific antigen were involved in both these processes. Taken together, our results show evidence that miR-372 may function as a tumor suppressor gene by regulating p65 in PCa and may provide a strategy for blocking PCa metastasis.

Genetic association between NFKB1 -94 ins/del ATTG Promoter Polymorphism and cancer risk: a meta-analysis of 42 case-control studies

Accumulating evidences have indicated that the functional -94 ins/del ATTG polymorphism in the promoter region of human nuclear factor-kappa B1 (NFKB1) gene may be associated with cancer risk. However, some studies yielded conflicting results. To clarify precise association, we performed a comprehensive meta-analysis of 42 case-control studies involving 43,000 subjects (18,222 cases and 24,778 controls). The overall results suggested that the -94 ins/del ATTG polymorphism had a decreased risk for cancer, reaching significant levels in five genetic models (dominant model: OR = 0.86, 95% CI = 0.79–0.95, P = 0.002; recessive model: OR = 0.84, 95% CI = 0.74–0.94, P = 0.003; homozygous model: OR = 0.77, 95% CI = 0.66–0.90, P = 0.001; heterozygous model: OR = 0.90, 95% CI = 0.83–0.98, P = 0.011; allelic model: OR = 0.89, 95% CI = 0.83–0.96, P = 0.002). Furthermore, the -94 ins/del ATTG polymorphism could confer a decreased or increased risk for cancer development among Asians and Caucasians, respectively. Additionally, the stratification analysis revealed a significant association between the variant and decreased risk of oral, ovarian, and nasopharyngeal cancer in Asians. After we adjusted p values using the Benjamini-Hochberg false discovery rate method to account for multiple comparisons, these associations remained.

β-Ionone and its analogs as promising anticancer agents

β-Ionone is an end-ring analog of β-carotenoids which widely distributed in fruit and vegetables. Recent studies have demonstrated anti-proliferative, anti-metastatic and apoptosis induction properties of β-ionone in vitro and in vivo. Also, the studies have focused on investigating the β-ionone action on different types of malignant cells and the possible mechanisms of action. Moreover, the quest of new synthetic β-ionone-based compounds possessing anti-proliferative, anti-metastatic and apoptosis induction activities may enable the discovery of compounds which can be used in combination regimes thus overcoming tumor resistance to conventional anticancer agents. These new agents will also be useful for targeting distinct signaling pathways, to activate selectively mechanisms for apoptosis in cancer cells but devoid of undesirable side effects. In this paper, we reviewed the potentialities of β-ionone and related compounds in cancer prevention and chemotherapy.

NF-κB and androgen receptor variant expression correlate with human BPH progression

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common, chronic progressive disease. Inflammation is associated with prostatic enlargement and resistance to 5α-reductase inhibitor (5ARI) therapy. Activation of the nuclear factor-kappa B (NF-κB) pathway is linked to both inflammation and ligand-independent prostate cancer progression.

METHODS

NF-κB activation and androgen receptor variant (AR-V) expression were quantified in transition zone tissue samples from patients with a wide range of AUASS from incidental BPH in patients treated for low grade, localized peripheral zone prostate cancer to advanced disease requiring surgical intervention. To further investigate these pathways, human prostatic stromal and epithelial cell lines were transduced with constitutively active or kinase dead forms of IKK2 to regulate canonical NF-κB activity. The effects on AR full length (AR-FL) and androgen-independent AR-V expression as well as cellular growth and differentiation were assessed.

RESULTS

Canonical NF-κB signaling was found to be upregulated in late versus early stage BPH, and to be strongly associated with non-insulin dependent diabetes mellitus. Elevated expression of AR-variant 7 (AR-V7), but not other AR variants, was found in advanced BPH samples. Expression of AR-V7 significantly correlated with the patient AUASS and TRUS volume. Forced activation of canonical NF-κB in human prostatic epithelial and stromal cells resulted in elevated expression of both AR-FL and AR-V7, with concomitant ligand-independent activation of AR reporters. Activation of NF-κB and over expression of AR-V7 in human prostatic epithelial cells maintained cell viability in the face of 5ARI treatment.

CONCLUSION

Activation of NF-κB and AR-V7 in the prostate is associated with increased disease severity. AR-V7 expression is inducible in human prostate cells by forced activation of NF-κB resulting in resistance to 5ARI treatment, suggesting a potential mechanism by which patients may become resistant to 5ARI therapy.

Anti-inflammatory therapies in TRAMP mice: delay in PCa progression

The aim of this study was to characterize the structural and molecular biology as well as evaluate the immediate and late responses of prostatic cancer in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model after treatment with goniothalamin (GTN) and celecoxib. The treated mice received GTN (150 mg/kg, gavage) or celecoxib (10 mg/kg, gavage) from 8 to 12 weeks of age. They were killed at different ages: the immediate-response groups at 12 weeks and the late-response groups at 22 weeks. The ventral prostate was collected for light microscopy, immunohistochemistry, western blotting, TUNEL, and ELISA. Morphological analyses indicated that GTN treatment delayed the progression of prostatic adenocarcinoma, leading to a significant decrease of prostatic lesion frequency in both experimental period responses to this treatment, mainly high-grade prostatic intraepithelial neoplasia and well-differentiated adenocarcinoma. Also, the celecoxib treatment showed a particular decrease in the proliferative processes (PCNA) in both the experimental periods. Despite celecoxib diminishing the COX2 and IGFR1 levels, GTN presented higher action spectrum considering the decrease of a greater molecular number involved in the proliferative and inflammatory processes in prostatic cancer. Goniothalamin attenuated the pro-inflammatory response in TRAMP prostatic microenvironment, delaying prostate cancer (PCa) progression. Celecoxib treatment was efficient in the regulation of COX2 in the TRAMP mice, mainly in the advanced disease grade. Finally, we concluded that inflammatory process control in early grades of PCa was crucial for the downregulation of the signaling pathways involved in the proliferative processes in advanced cancer grades.

Polymorphisms in NF-κB pathway genes & their association with risk of lung cancer in the Chinese population

Objective:

To investigate the association of NFKB1 -94 ins/del ATTG, NFKBIA -826C>T and NFKBIA -881A>G polymorphisms with risk of lung cancer in a Chinese population.

Methods:

Genotyping of the polymorphisms were performed on 1,436 subjects (718 cases and 718 controls) by using PCR-RFLP technique, followed by DNA sequencing.

Results:

We found a significant risk reduction associated with heterozygous ins/del (OR=0.705, 95% CI=0.566-0.878, P=0.002) and variant del/del (OR=0.342, 95% CI=0.221-0.528, P<0.001) genotypes of the NFKB1 polymorphism. In contrast, the heterozygous and variantgenotypes of theNFKBIA polymorphisms showed association with increased lung cancer risk (NFKBIA -826 CT,OR=1.256, 95%CI=1.004-1.572, P=0.046; TT,OR=1.773, 95% CI=1.131-2.778, P=0.013; NFKBIA -881 AG,OR=1.277, 95% CI=1.023-1.599, P=0.031; GG,OR=1.801, 95% CI=1.169-2.775, P=0.008). Several genotypic combinations of the three polymorphisms also showed significant association with lung cancer risk. The risk association of NFKB1 polymorphism remained significant when analyses were done according to gender and smoking status (P<0.05). The significance of NFKBIA risk association was not observed when gender-specific analyses were made (P>0.05), while only NFKBIA -881 GG genotype showed significant risk association among smokers when analyzed according to smoking status (P=0.032).

Conclusions:

Polymorphisms in NFKB1 and NFKBIAgenes were associated with risk of lung cancer.

Knockdown of AKR1C3 exposes a potential epigenetic susceptibility in prostate cancer cells

BACKGROUND

The aldo-keto reductase 1C3 (AKR1C3) has been heavily implicated in the propagation of prostate malignancy. AKR1C3 protein is elevated within prostate cancer tissue, it contributes to the formation of androgens and downstream stimulation of the androgen receptor (AR). Elevated expression of AKR1C3 is also reported in acute myeloid leukemia but the target nuclear receptors have been identified as members of the peroxisome-proliferator activated receptor (PPARs) subfamily. Thus, AKR1C3 cancer biology is likely to be tissue dependent and hormonally linked to the availability of ligands for both the steroidogenic and non-steroidogenic nuclear receptors.

METHODS

In the current study we investigated the potential for AKR1C3 to regulate the availability of prostaglandin-derived ligands for PPARg mainly, prostaglandin J2 (PGJ2). Using prostate cancer cell lines with stably reduced AKR1C3 levels we examined the impact of AKR1C3 upon proliferation mediated by PPAR ligands.

RESULTS

These studies revealed knockdown of AKR1C3 had no effect upon the sensitivity of androgen receptor independent prostate cancer cells towards PPAR ligands. However, the reduction of levels of AKR1C3 was accompanied by a significantly reduced mRNA expression of a range of HDACs, transcriptional co-regulators, and increased sensitivity towards SAHA, a clinically approved histone deacetylase inhibitor.

CONCLUSIONS

These results suggest a hitherto unidentified link between AKR1C3 levels and the epigenetic status in prostate cancer cells. This raises an interesting possibility of a novel rational to target AKR1C3, the utilization of AKRIC3 selective inhibitors in combination with HDAC inhibition as part of novel epigenetic therapies in androgen deprivation therapy recurrent prostate cancer.

ProSim: A Method for Prioritizing Disease Genes Based on Protein Proximity and Disease Similarity

Predicting disease genes for a particular genetic disease is very challenging in bioinformatics. Based on current research studies, this challenge can be tackled via network-based approaches. Furthermore, it has been highlighted that it is necessary to consider disease similarity along with the protein's proximity to disease genes in a protein-protein interaction (PPI) network in order to improve the accuracy of disease gene prioritization. In this study we propose a new algorithm called proximity disease similarity algorithm (ProSim), which takes both of the aforementioned properties into consideration, to prioritize disease genes. To illustrate the proposed algorithm, we have conducted six case studies, namely, prostate cancer, Alzheimer's disease, diabetes mellitus type 2, breast cancer, colorectal cancer, and lung cancer. We employed leave-one-out cross validation, mean enrichment, tenfold cross validation, and ROC curves to evaluate our proposed method and other existing methods. The results show that our proposed method outperforms existing methods such as PRINCE, RWR, and DADA.

Redox nanoparticles inhibit curcumin oxidative degradation and enhance its therapeutic effect on prostate cancer

Curcumin is a phytochemical with diverse molecular targets and is well known for its anti-tumor potential. However, it has limited application in cancer therapy because curcumin undergoes rapid oxidative degradation at physiological conditions resulting in poor stability and bio-availability. In this study, we were able to suppress curcumin's oxidative degradation by encapsulating it in a nanoparticle that also acts as a radical scavenger. We prepared curcumin-loaded pH-sensitive redox nanoparticles (RNP(N)) by self-assembling amphiphilic block copolymers conjugated with reactive oxygen species (ROS) scavenging nitroxide radicals to ensure the delivery of minimally degraded curcumin to target regions. In vitro analysis confirmed that the entrapment of both curcumin and nitroxide radicals in the hydrophobic core of RNP(N) suppressed curcumin degradation in conditions mimicking the physiological environment. Evaluation of apoptosis-related molecules in the cells, such as ceramides, caspases, apoptosis-inducing factor, and acid ceramidase revealed that curcumin loaded RNP(N) induced strong apoptosis compared to free curcumin. Lastly, intravenous injection of curcumin loaded RNP(N) suppressed tumor growth in vivo, which is due to the increased bio-availability and significant ROS scavenging at tumor sites. These results demonstrated that RNP(N) is a promising drug carrier with unique ROS-scavenging abilities, and it is able to overcome the crucial hurdle of curcumin's limitations to enhance its therapeutic potential.

Tumor-suppressive microRNA-497 targets IKKβ to regulate NF-κB signaling pathway in human prostate cancer cells

BACKGROUND

Prostate cancer (PCa) is one of the most prevalent malignant tumors, PCa-related death is mainly due to the high probability of metastasis. MicroRNAs (miRNAs) play an important role in cancer initiation, progression and metastasis by regulating their target genes.

METHODS

real-time PCR was used to detected the expression of microRNA-497. The molecular biological function was investigated by using cell proliferation assays, cell cycle assay, and migration and invasion assay. We used several Algorithms and confirmed that IKKβ is directly regulated by miR-497.

RESULTS

Here, we found miR-497 is downregulated in human prostate cancer (PCa) and inhibites the proliferation activity, migration and invasion of PC3-AR cells. Subsequently, IKKβ is confi rmed as a target of miR-497. Furthermore, knockdown of IKKβ expression resulted in decreased proliferation activity, migration and invasion. Finally, similar results was found after treatment with a novel IKK-β inhibitor (IMD-0354) in PC3-AR cells. CDK8, MMP-9, and PSA were involved in all these process.

CONCLUSION

Taken together, our results show evidence that miR-497 may function as a tumor suppressor genes by regulating IKK-β in PCa, and may provide a strategy for blocking PCa metastasis.

The NFKB1 polymorphism (rs4648068) is associated with the cell proliferation and motility in gastric cancer

BACKGROUND

We have demonstrated previously that NFKB1 single nucleotide polymorphism (SNP) rs4648068 GG homozygote was associated with the increased risk of gastric cancer in Chinese Han population. In this study, we constructed the recombinant plasmid pGL3-AA, pGL3-GG, pGL3-AA-NFKB and pGL3-GG-NFKB to investigate the function of rs4648068 by cell biology experiments.

METHODS

Quantitative real-time PCR was used to detect NFKB1 SNP rs4648068 genotype in the patients with gastric cancer. Anti-NF-κB1 p50 polyclonal antibodies were used for immunohistochemical analysis of the tissue specimens. The subsection of NFKB1 containing the promoter site and adjacent three consecutive exons were obtained by PCR technique and subcloned into the vector pGL3-Basic. Dual-Luciferase reporter assay was used to detect the transcriptional activity of the constructed promoter. Effects of transcription factor NFKB1 on C/EBPβ expression were determined by chromatin immunoprecipitation and Western analysis. Furthermore, proliferation and invasion ability of the transduced cell were also measured and compared.

RESULTS

Intensive staining for p50 expression was observed in the tissues of GG genotype patients, compared with those of GA group and AA genotype patients. The transcriptional activity of rs4648068 (A > G) by dual-Luciferase reporter assay suggested that the luciferase activity of homozygote group (pGL3-GG) was greater than that of the control (pGL3-AA), especially at the stimulation of LPS. We found that the luciferase activity was also influenced by pGL3-GG levels. The effects of NFKB1 rs4648068 were enhanced by rs4648065 on the transduced cells. The interaction between NFKB1 promoter nucleotide sequence and C/EBPβ was regulated by the functional SNP rs4648068 in SGC-7901 cells. Our data indicated that the transduction of pGL3 expression plasmid pGL3-GG-NFKB improved the proliferation and motility of gastric cancer cells. Correspondingly, the homozygote GG of SNP rs4648068 strengthened the transcriptional activity of NFKB1 and influenced the cell biological activity.

CONCLUSION

The transcriptional activity of NFKB1 was associated with SNP rs4648068, and this functional SNP site has the important effects on cell proliferation and motility.

Minireview: Tipping the balance: ligand-independent activation of steroid receptors

Steroid receptors are prototypical ligand-dependent transcription factors and a textbook example for allosteric regulation. According to this canonical model, binding of cognate steroid is an absolute requirement for transcriptional activation. Remarkably, the simple one ligand-one receptor model could not be farther from the truth. Steroid receptors, notably the sex steroid receptors, can receive multiple inputs. Activation of steroid receptors by other signals, working through their own signaling pathways, in the absence of the cognate steroids, represents the most extreme form of signaling cross talk. Compared with cognate steroids, ligand-independent activation pathways produce similar but not identical outputs. Here we review the phenomena and discuss what is known about the underlying molecular mechanisms and the biological significance. We hypothesize that steroid receptors may have evolved to be trigger happy. In addition to their cognate steroids, many posttranslational modifications and interactors, modulated by other signals, may be able to tip the balance.

Chronic inflammatory mediators enhance prostate cancer development and progression

Chronic inflammation is postulated to influence prostate cancer progression. Preclinical studies have claimed that inflammatory mediators are involved in prostate cancer development and therefore suggested these as attractive targets for intervention. However, among the many pro-inflammatory mediators, there is no consensus regarding the identity of the primary one(s). In clinical studies, chronic inflammation has been found in prostate tumor specimens, and tissues resected for treatment of benign prostatic hyperplasia (BPH). Although collective evidence from molecular, experimental and clinical data suggests that inflammation can contribute or promote prostate carcinogenesis, an etiologic link has not yet been established. Moreover, the role of chronic inflammation in the onset of castration resistant and metastatic disease is unclear. Therefore it is important to open a dialog regarding recent findings on how chronic inflammatory mediators contribute to prostate cancer progression, and their usefulness to prevent disease progression. In this commentary, we assess the current literature with respect to chronic inflammation as a potential initiator and promoter of prostate carcinogenesis and discuss the prospects for its potential clinical applications.

VIP induces NF-κB1-nuclear localisation through different signalling pathways in human tumour and non-tumour prostate cells

The nuclear factor κB (NF-κB) is a powerful activator of angiogenesis, invasion and metastasis. Transactivation and nuclear localisation of NF-κB is an index of recurrence in prostate cancer. Vasoactive intestinal peptide (VIP) exerts similar effects in prostate cancer models involving increased expression of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) which are related to NF-κB transactivation. Here we studied differential mechanisms of VIP-induced NF-κB transactivation in non-tumour RWPE-1 and tumour LNCaP and PC3 human prostate epithelial cells. Immunofluorescence studies showed that VIP increases translocation of the p50 subunit of NF-κB1 to the nucleus, an effect that was inhibited by curcumin. The signalling transduction pathways involved are different depending on cell transformation degree. In control cells (RWPE1), the effect is mediated by protein kinase A (PKA) activation and does not implicate extracellular signal-regulated kinase (ERK) or phosphoinositide 3-kinase (PI3-K) pathways whereas the opposite is true in tumour LNCaP and PC3 cells. Exchange protein directly activated by cAMP (EPAC) pathway is involved in transformed cells but not in control cells. Curcumin blocks the activating effect of VIP on COX-2 promoter/prostaglandin E2 (PGE2) production and VEGF expression and secretion. The study incorporates direct observation on COX-2 promoter and suggests that VIP effect on VEGF may be indirectly mediated by PGE2 after being synthesised by COX-2, thus amplifying the initial signal. We show that the signalling involved in VIP effects on VEGF is cAMP/PKA in non-tumour cells and cAMP/EPAC/ERK/PI3K in tumour cells which coincides with pathways mediating p50 nuclear translocation. Thus, VIP appears to use different pathways for NF-κB1 (p50) transactivation in prostate epithelial cells depending on whether they are transformed or not. Transformed cells depend on pro-survival and pro-proliferative signalling pathways involving ERK, PI3-K and cAMP/EPAC which supports the potential therapeutic value of these targets in prostate cancer.

Radiation protection of the gastrointestinal tract and growth inhibition of prostate cancer xenografts by a single compound

Normal tissue toxicity markedly reduces the therapeutic index of genotoxic anticancer agents, including ionizing radiation. Countermeasures against tissue damage caused by radiation are limited by their potential to also protect malignant cells and tissues. Here, we tested a panel of signal transduction modifiers for selective radioprotection of normal but not tumor tissues. These included three inhibitors of GSK3 (LiCl, SB216763, and SB415286) and two inhibitors of NF-κB (ethyl pyruvate and RTA 408). Among these, the thiol-reactive triterpenoid RTA 408 emerged as a robust and effective protector of multiple organ systems (gastrointestinal, skin, and hemopoietic) against lethal doses of radiation. RTA 408 preserved survival and proliferation of intestinal crypt cells in lethally irradiated mice while reducing apoptosis incidence in crypts and villi. In contrast, RTA 408 uniformly inhibited growth of established CWR22Rv1, LNCaP/C4-2B, PC3, and DU145 xenografts either alone or combined with radiation. Antitumor effects in vivo were associated with reduced proliferation and intratumoral apoptosis and with inhibition of NF-κB-dependent transcription in PC3 cells. Selective protection of normal tissue compartments by RTA 408 critically depended on tissue context and could not be replicated in vitro. Collectively, these data highlight the potential of RTA 408 as a cytoprotective agent that may be safely used in chemoradiation approaches.