Cucurbitacin B Inhibits the Proliferation of WPMY-1 Cells and HPRF Cells via the p53/MDM2 Axis.

Modern research has shown that Cucurbitacin B (Cu B) possesses various biological activities such as liver protection, anti-inflammatory, and anti-tumor effects. However, the majority of research has primarily concentrated on its hepatoprotective effects, with limited attention devoted to exploring its potential impact on the prostate. Our research indicates that Cu B effectively inhibits the proliferation of human prostate stromal cells (WPMY-1) and fibroblasts (HPRF), while triggering apoptosis in prostate cells. When treated with 100 nM Cu B, the apoptosis rates of WPMY-1 and HPRF cells reached 51.73 ± 5.38% and 26.83 ± 0.40%, respectively. In addition, the cell cycle assay showed that Cu B had a G2/M phase cycle arrest effect on WPMY-1 cells. Based on RNA-sequencing analysis, Cu B might inhibit prostate cell proliferation via the p53 signaling pathway. Subsequently, the related gene and protein expression levels were measured using quantitative real-time PCR (RT-qPCR), immunocytochemistry (ICC), and enzyme-linked immunosorbent assays (ELISA). Our results mirrored the regulation of tumor protein p53 (TP53), mouse double minute-2 (MDM2), cyclin D1 (CCND1), and thrombospondin 1 (THBS1) in Cu B-induced prostate cell apoptosis. Altogether, Cu B may inhibit prostate cell proliferation and correlate to the modulation of the p53/MDM2 signaling cascade.

Bisphenol AF Induces Prostatic Dorsal Lobe Hyperplasia in Rats through Activation of the NF-κB Signaling Pathway.

Bisphenol AF (BPAF) represents a common environmental estrogenic compound renowned for its capacity to induce endocrine disruptions. Notably, BPAF exhibits an enhanced binding affinity to estrogen receptors, which may have more potent estrogenic activity compared with its precursor bisphenol A (BPA). Notwithstanding, the existing studies on BPAF-induced prostate toxicity remain limited, with related toxicological research residing in the preliminary stage. Our previous studies have confirmed the role of BPAF in the induction of ventral prostatic hyperplasia, but its role in the dorsal lobe is not clear. In this study, BPAF (10, 90 µg/kg) and the inhibitor of nuclear transcription factor-κB (NF-κB), pyrrolidinedithiocarbamate (PDTC, 100 mg/kg), were administered intragastrically in rats for four weeks. Through comprehensive anatomical and pathological observations, as well as the assessment of PCNA over-expression, we asserted that BPAF at lower doses may foster dorsal prostatic hyperplasia in rats. The results of IHC and ELISA indicated that BPAF induced hyperplastic responses in the dorsal lobe of the prostate by interfering with a series of biomarkers in NF-κB signaling pathways, containing NF-κB p65, COX-2, TNF-α, and EGFR. These findings confirm the toxic effect of BPAF on prostate health and emphasize the potential corresponding mechanisms.

The Antiproliferative and Proapoptotic Effects of Cucurbitacin B on BPH-1 Cells via the p53/MDM2 Axis.

Cucurbitacin B (Cu B), a triterpenoid compound, has anti-inflammatory and antioxidant activities. Most studies only focus on the hepatoprotective activity of Cu B, and little effort has been geared toward exploring the effect of Cu B on the prostate. Our study identified that Cu B inhibited the proliferation of the benign prostatic hyperplasia epithelial cell line (BPH-1). At the molecular level, Cu B upregulated MDM2 and thrombospondin 1 (THBS1) mRNA levels. Immunocytochemistry results revealed that the protein expressions of p53 and MDM2 were upregulated in BPH-1 cells. Furthermore, Cu B upregulated THBS1 expression and downregulated COX-2 expression in the BPH-1 cell supernatant. Altogether, Cu B may inhibit prostate cell proliferation by activating the p53/MDM2 signaling cascade and downregulating the COX-2 expression.

Bisphenol A exposure triggers the malignant transformation of prostatic hyperplasia in beagle dogs via cfa-miR-204/KRAS axis.

The prostatic toxicity of bisphenol A (BPA) exposure is mainly associated with hormonal disturbances, thus interfering with multiple signal pathways and increasing the susceptibility to prostatic lesions. This study concentrates predominantly on the potential effect and mechanisms of low-dose BPA exposure on prostates in adult beagle dogs. The dogs were orally given BPA (2, 6, 18 µg/kg/day) and vehicle for 8 weeks, followed by blood collection and dissection. The ascended organ coefficient and volume of prostates, thickened epithelium, as well as histopathological observation have manifested that BPA exposure could trigger the aberrant prostatic hyperplasia in beagle dogs. Hormone level detection revealed that the ratios of estradiol (E2) to testosterone (T) (E2/T) and prolactin (PRL) to T (PRL/T) were up-regulated in the serum from BPA group. Based on microRNA (miRNA) microarray screening and functional enrichment analysis, BPA might facilitate the progression of prostate tumorigenesis in beagle dogs via cfa-miR-204 and its downstream target KRAS oncogene. Subsequently, the overexpression of KRAS, CDKN1A, MAPK1, VEGFA, BCL2 and PTGS2 was validated. These findings provide a series of underlying targets for preventing the initiation and metastasis of BPA-induced prostatic hyperplasia and tumorigenesis, while the regulatory relationship headed with KRAS requires further investigation.

Individual and Combined Effect of Bisphenol A and Bisphenol AF on Prostate Cell Proliferation through NF-κB Signaling Pathway.

The ubiquitous environmental endocrine disruptor bisphenol A (BPA) can induce prostatic dysfunction. However, to date, studies have focused little on the perturbations of prostate health initiated by the BPA derivative bisphenol AF (BPAF) and co-exposure to bisphenol compounds. An in vivo study orally administrated male rats with BPA (10, 90 µg/kg), BPAF (10, 90 µg/kg) and the inhibitor of nuclear transcription factor-κB (NF-κB), pyrrolidinedithiocarbamate (PDTC, 100 mg/kg). Based on the anatomical analysis, pathological observations and PCNA over-expression, we considered that low-dose BPA and BPAF facilitated ventral prostatic hyperplasia in rats. The results of IHC and ELISA mirrored the regulation of NF-κB p65, COX-2, TNF-α and EGFR in BPA- and BPAF-induced prostatic toxicity. An in vitro study found that the additive effect of combined exposure to BPA (10 nM) and BPAF (10 nM) could cause an elevation in the proliferation of and a reduction in the apoptosis level of human prostate stromal cells (WPMY-1) and fibroblasts (HPrF). Meanwhile, the underlying biomarkers of the NF-κB signaling pathway also involved the abnormal proliferative progression of prostate cells. The findings recapitulated the induction of BPAF exposure and co-treatment with BPA and BPAF on prostatic hyperplasia and emphasized the modulation of the NF-κB signaling pathway.

BPA-induced prostatic hyperplasia in vitro is correlated with the unbalanced gene expression of AR and ER in the epithelium and stroma.

As a typical environmental endocrine disruptor (EED), bisphenol A (BPA) can induce pathological hyperplasia of the prostatic epithelium and stroma. This study concentrates mainly on the effect and underlying mechanisms of BPA on prostatic hyperplasia, which is based on the culture of primary human prostate epithelial cells (HPEpiC) and human prostate fibroblasts (HPrF). In an effect to screen the optimal pro-survival BPA levels, HPEpiC and HPrF were, respectively, exposed to concentration gradients of BPA (10-12 M-10-4 M) solution diluted with two corresponding medium and incubated for 72 h at 37°C. CCK-8 assay showed that 10-9 M-10-5 M BPA could facilitate the proliferation of HPEpiC, while similar proliferative effect of HPrF only needed 10-11 M-10-7 M BPA. HPrF were more sensitive to BPA than HPEpiC. The qualification of PCNA gene expression measured using quantitative real-time polymerase chain reaction (qRT-PCR) also mirrored the BPA-induced cell proliferation. Additionally, our results considered that androgen receptor (AR), estrogen receptor (ERα, ERß), and NFKB1 gene expressions exhibited up-regulation in HPEpiC treated with 10-9 M BPA for 72 h. However, in HPrF, the identical BPA treatment could activate ERα, ERß, and NFKB1 gene expressions and down-regulated the expression of AR levels. It is further confirmed that low-dose BPA can indeed promote the proliferation of human prostate cells in vitro, and the mechanisms of BPA for prostatic epithelial and stromal hyperplasia may not be consistent.

Oral exposure to DEHP may stimulate prostatic hyperplasia associated with upregulation of COX-2 and L-PGDS expressions in male adult rats.

Di-(2-ethylhexyl) phthalate (DEHP), a typical environmental endocrine disruptor (EED), can disrupt estrogen and androgen secretion and metabolism process, thus inducing dysfunctional reproduction such as impaired gonadal development and spermatogenesis disorder. Prostaglandin synthases (PGS) catalyze various prostaglandins biosynthesis, involved in inflammatory cascade and tumorigenesis. Yet, little is known about how PGS may impact prostatic hyperplasia development and progression. This study concentrates predominantly on the potential prostatic toxicity of DEHP exposure and the mediating role of PGS. In vivo study, adult male rats were administered via oral gavage 30 µg/kg/d, 90 µg/kg/d, 270 µg/kg/d, 810 µg/kg/d DEHP or vehicle for four weeks. The results elucidated that low-dose DEHP may cause the proliferation of the prostate with an increased PCNA/TUNEL ratio. Given the importance of estrogens and androgens in prostatic hyperplasia, our first objective was to evaluate the levels of sex hormones. DEHP improved the ratio of estradiol (E2)/testosterone (T) in a dose-dependent manner and upregulated estrogen receptor alpha (ERα) and androgen receptor (AR) expressions. Prostaglandin synthases, including cyclooxygenase-2 (COX-2) and lipocalin-type prostaglandin D synthase (L-PGDS), were significantly upregulated in the ventral prostate. COX-2 and L-PGDS might mediate the tendency of prostatic hyperplasia induced by low-dose DEHP through estradiol/androgen regulation and imbalance between proliferation and apoptosis in vivo. These findings provide the first evidence that prostaglandin synthases contribute to the tendency toward benign prostatic hyperplasia induced by DEHP. Further investigations will have to be performed to facilitate an improved understanding of the role of prostaglandin synthases in DEHP-induced prostatic lesions.

Proteomic analysis of human prostate cancer PC-3M-1E8 cells and PC-3M-2B4 cells of same origin but with different metastatic potential.

Prostate cancer (PCa) is the second most frequently diagnosed cancer and the fifth leading cause of death from cancer in men worldwide. Increased understanding of the prostate cancer metastasis mechanisms will help identify more efficient intervention strategies to prevent or treat this deadly disease in the future. To identify the candidate proteins that contribute to metastasis of PCa, isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis was performed to explore differentially expressed proteins between two homologous human prostate cancer cell lines including highly-metastatic PC-3M-1E8 cell line and poorly-metastatic PC-3M-2B4 cell line. Here, a total of 58 proteins were identified to be significantly differentially expressed between PC-3M-1E8 and PC-3M-2B4 cells, which were further verified using real-time quantitative PCR and western blot analysis. The bioinformatic analysis suggested that the differentially expressed proteins, like MMP1 and FHL1, may contribute to the higher metastatic ability of PC-3M-1E8 cells than PC-3M-2B4 cells. In addition, functional analyses proved MMP1's positive effect on the higher metastatic ability of PC-3M-1E8 cells than PC-3M-2B4 cells. These findings provided a unique resource to specifically reveal the complex molecular regulatory mechanisms underlying the progression of prostate cancer from poorly-metastatic to highly-metastatic stage.

Solid lipid nanoparticles reduce systemic toxicity of docetaxel: performance and mechanism in animal.

Nanotechnology presents great potential for increasing efficacy of docetaxel while reducing side-effects and toxicity. However, in vivo toxicity of nano-formulation of docetaxel has not been systemically investigated yet. Herein, the new docetaxel-loaded solid lipid nanoparticles (DSNs) were prepared, and systemic toxicity of DSNs in different animals was comprehensively investigated. The experimental results showed that no allergenicity and vascular irritation were induced by DSNs at the highest drug concentration of clinical infusion. The maximum tolerated dose (MTD) of DSNs was as high as 400 mg/kg in mice while the medial lethal dose (LD50) of Taxotere® was 149.31 mg/kg. The long-term toxicity of DSNs compared with Taxotere® in beagle dogs by intravenous infusion weekly for four weeks showed that the administration of Taxotere® at 1 mg/kg brought about severe signs of toxicity such as skin flushing, vocalization and salivation. However, no abnormal reactions appeared on animals treated with DSNs at dose of 4 mg/kg. At the same dose level, DSNs induced more minor decreases in body weight gains, slighter hemotoxicity (changes in some clinical hematology and biochemistry parameters), cardiac toxicity, hepatotoxicity and myelosuppression than Taxotere®. These results could provide an important reference for developing the novel delivery system of docetaxel.