Multifaceted impact of adipose conditioned media: Obesity-driven promotion of prostate cancer and cancer stem cell dynamics

Obesity is an established risk factor for the development and progression of prostate cancer (PC). This study used adipose conditioned media (ACM) from differentiated adipocytes to assess its effect on PC development and aggressiveness. Due to limited research on ACM's impact on isolated PC stem cells (PCSCs), we also examined CD44+ PCSCs. ACM notably boosted interleukin-1β (IL-1β), IL-6, and IL-8 production in normal prostate epithelial cells and LNCaP cells. It also increased IL-6 and IL-8 production in PC3 and CD44+ LNCaP cells, and IL-1β and IL-6 production in CD44+ PC3 cells. This indicates that ACM induces the production of inflammatory cytokines in both cancer and prostate epithelial cells. Furthermore, ACM promoted proliferation in androgen receptor (AR)-negative PC3 cells, CD44+  PC3 PCSCs, and nonmalignant RWPE cells, without affecting AR-positive LNCaP cells. In addition, ACM-enhanced invasion and migration potential in both PC3 and CD44+  PC3 cells. Western blot analysis indicated the involvement of NF-κB and AKT pathways in ACM-induced proliferation in PC3 cells and NF-κB in PCSCs. In ACM-treated PC3 cells, E-cadherin was downregulated, while N-cadherin, Snail, vimentin, fibronectin, and Twist were upregulated, suggesting ACM-induced invasion via classical epithelial-to-mesenchymal transition (EMT) pathways. In response to ACM, PCSCs exhibited increased expression of E-cadherin, Snail, and vimentin, which are partial EMT markers promoting stemness and resistance to apoptosis. In addition, increased expressions of Nanog, Oct3/4, survivin, and Bcl-2 were observed. Although the molecules we studied have diverse effects on cellular regulation, our data emphasize obesity's multifaceted role in promoting and aggressing PC, notably affecting PCSC populations.

Pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor increases the efficacy of cabazitaxel by inducing apoptosis and decreasing cancer stem cells

Cancer stem cells (CSCs) are associated with metastasis and recurrence in prostate cancer as well as other cancers. We aimed to enhance the sensitivity of cabazitaxel in prostate cancer cell therapy by targeting CSCs with a Wnt inhibitor and salinomycin pretreatment. PC3, DU-145, and LNCaP human prostate cancer cells were exposed to Wnt/β-catenin pathway inhibitor CCT036477 (iWnt) with salinomycin for 48 h, followed by cabazitaxel treatment for 48 h. Cell viability, mRNA, and protein expression changes were evaluated by MTT, RT-qPCR, and Western blot assays, respectively. Apoptosis was determined by image-based cytometry, and cell migration was assessed by wound healing assay. Three-dimensional culture was established to assess the malignant phenotype and stemness potential of transformed or cancer cells. CD44 + CSCs were isolated using magnetic-activated cell sorting system. Pretreatment of PC3, DU-145, and LNCaP cells with salinomycin iWnt significantly sensitized the cells to cabazitaxel therapy. Spheroid culture confirmed that the treatment modality was more effective than a single administration of chemotherapy. The pretreatment of PC3 cells increased the rate of apoptosis compared to single administration of cabazitaxel, which downregulated Bcl-2 and upregulated caspase 3, caspase 8 expressions. The pretreatment suppressed cell migration, downregulated the expression of Sox2 and Nanog, and significantly reduced CD44 + CSC numbers. Notably, the treatment modality reduced pAKT, p-P38 MAPK, and pERK1/2. The data suggest that pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor may increase the efficacy of cabazitaxel therapy by inhibiting cell proliferation and migration, and eliminating cancer stem cells.

Cytotoxic and Antimigratory Activity of Retrochalcones from Glycyrrhiza echinata L. on Human Cancer Cells

Cytotoxic activity-guided fractionation studies on Glycyrrhiza echinata roots led to the isolation of eight compounds (1-8). Chemical structures of the isolates were identified by NMR and MS analysis. Among the tested molecules, retrochalcones namely echinatin (3) (IC₅₀ =23.45-41.83 μM), licochalcone B (4) (IC₅₀ =36.04-39.53 μM) and tetrahydroxylmethoxychalcone (5) (IC₅₀ =7.09-80.81 μM) were the most active ones against PC3, MCF7 and HepG2 cells. Moreover, 5 exhibited selectivity on prostate cancer cells (SI: 5.19). Hoechst staining and Annexin V/PI binding assays as well as cell cycle analysis on the compounds 3 (23 μM) and 5 (5 and 7 μM) demonstrated that these retrochalcones induced apoptosis and significantly suppressed cell cycle in G₁ and G₂ /M phases. Furthermore, 3 and 5 showed antimigratory effects on PC3 cells by wound healing assay. The results indicated that tested retrochalcones most particularly 5 could be potential anticancer drug candidates that prevent proliferation and migration of cancer cells.

Inhibition of Ribonucleotide Reductase Induces Endoplasmic Reticulum Stress and Apoptosis, Leading to the Death of Docetaxel-resistant Prostate Cancer Cells

BACKGROUND

The development of chemotherapy resistance in prostate cancer (PCa) patients poses a significant obstacle to disease progression. Ribonucleotide reductase is a crucial enzyme for cell division and tumor growth. Triapine, an inhibitor of ribonucleotide reductase, has shown strong anti-tumor activity in various types of cancers. However, the effect of triapine on docetaxel-resistant (DR) human PCa cells has not been explored previously.

AIM

This study aimed to examine the potential anti-proliferative effects of triapine in PC3-DR (docetaxel-resistant) cells.

METHODS

Cell viability was determined by the MTT test, and apoptosis and cell cycle progression were analyzed by image-based cytometer. mRNA and protein expression were assessed by RT-qPCR and western blot, respectively.

RESULTS

Triapine administration significantly reduced PC3 and PC3-DR cells' survival, while the cytotoxic effect was higher in PC3-DR cells. Cell death resulting from inhibition of ribonucleotide reductase was mediated by endoplasmic reticulum stress, induction of apoptosis, and cell cycle arrest. The findings were supported by the upregulation of caspases, Bax, Bak, P21, P27, P53, TNF-α, FAS, and FASL, and downregulation of Bcl2, Bcl-XL, cyclin-dependent kinase 2 (CDK2), CDK4, cyclins, and heat shock proteins expression. According to the data, the reduction of ABC transporter proteins and NF-ĸB expression may play a role in triapine-mediated cytotoxicity in docetaxel-resistant cells.

CONCLUSION

Based on our findings, triapine emerges as a promising chemotherapeutic approach for combating docetaxel- resistant prostate cancer.

Abiraterone acetate in combination with apigenin attenuates survival of human castration-sensitive prostate cancer cells

BACKGROUND

Abiraterone acetate (AA) is a selective inhibitor of CYP17 α-hydroxylase which is crucial for androgen biosynthesis. Apigenin (Api) is a natural plant-derived flavonoid with potent antiproliferative and anti-migration effects.

OBJECTIVES

We aimed to investigate the possible role of Api in combination with the androgen receptor inhibitor AA in the treatment of androgen-sensitive human prostate cancer LNCaP cells.

METHODS

The cells were either exposed to 10 µM AA, 25 µM Api, or in combination for 48 hours, then the viability rate was determined by MTT test, whilst apoptosis and cell cycle phases were assessed by image-based cytometry. Expression of selected mRNA and proteins were evaluated by RT-qPCR and Western blot, respectively.

RESULTS

The combination of AA and Api significantly inhibited LNCaP as well as androgen-insensitive PC3 cell survival in a manner more marked than seen with either single treatment. Co-administration of Api with AA triggered apoptosis. This effect was demonstrated by Hoechst staining, and up-regulation of Bax, cytochrome c, caspase -3, -8 and down-regulation of Bcl-2 expression confirmed the effect. AA and Api each individually arrest the cell cycle in the G1 phase, with dual application leading to no further increase in the effect produced. The expression of NF-κB p105/p50 and the phosphorylation of AKT markedly decreased after apigenin treatment, with combination treatment leading to a favourable effect in terms of further augmenting the reduction.

CONCLUSION

The co-administration of Api with AA strongly enhances the efficacy of AA therapy in the treatment of prostate cancer cells. These data suggest that the combination of AA and Api would be a potential chemotherapeutic strategy against prostate cancer.

Eupatilin attenuates TGF-β2-induced proliferation and epithelial-mesenchymal transition of retinal pigment epithelial cells

PURPOSE

The main characteristic of proliferative vitreoretinopathy (PVR) is migration, adhesion, and epithelial-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPE). Eupatilin is a naturally occurring flavone that has the potential to inhibit cell proliferation and EMT. However, its efficacy on the PVR model induced by transforming growth factor-2 (TGF-β2) is unknown. In this study, the potential effect of eupatilin on proliferation and EMT in the treatment of RPE was investigated.

METHODS

Serum starved human RPE cells (ARPE-19) were treated with 10 ng/ml TGF-β2 alone or co-treated with 25 μM eupatilin for 48 h. Quantitative real-time PCR and Western blot analysis were used to assess targets at the mRNA and protein expression level, respectively. Apoptosis and cell cycle progression was assessed by image-based cytometry. The effect of treatment on cell migration was evaluated by wound healing assay.

RESULTS

Eupatilin inhibited TGF-β2-induced RPE cell proliferation via regulating the cell cycle and inducing apoptosis. TGF-β2 upregulated mRNA expression of mesenchymal markers fibronectin and vimentin was significantly downregulated by the treatment, while the epithelial markers E-cadherin and occludin expression was upregulated. The therapy significantly suppressed TGF-β2 encouraged cell migration through downregulating the expression of transcription factors Twist, Snail, and ZEB1 induced by TGF-β2. Furthermore, eupatilin significantly inhibited the expression of MMP-1, -7, and -9, and suppressed NF-κB signalling.

CONCLUSION

These results suggest that eupatilin could inhibit the proliferation and transformation into fibroblast-like cells of RPE cells; thus the agent may be a potential therapeutic value in treating PVR.

Eupatilin Inhibits the Proliferation and Migration of Prostate Cancer Cells through Modulation of PTEN and NF-κB Signaling

BACKGROUND

Despite advances in the treatment of prostate cancer, side effects and the risks of developing drug resistance require new therapeutic agents. Eupatilin is a secondary metabolite of Artemisia asiatica and has shown potential anti-tumor activity in some cancers, but its potential in prostate cancer treatment has not yet been evaluated.

OBJECTIVE

The aim of the study was to investigate the effectiveness of eupatilin on prostate cancer cell proliferation and migration.

METHODS

Human prostate cancer PC3 and LNCaP cells were exposed to eupatilin and its efficacy on cell survival was determined by the MTT test. Apoptosis and cell cycle phases were evaluated by an image-based cytometer. Cell migration and invasion were evaluated by wound healing and matrigel migration assays; the expression of mRNA and protein was assessed by RT-qPCR and Western blot, respectively.

RESULTS

Eupatilin time- and dose-dependently reduced the viability of prostate cancer cells. Exposure of PC3 cells to 12.5μM-50μM eupatilin resulted in apoptosis by upregulating the expression of caspase 3, Bax and cytochrome c. Annexin V assessment also confirmed that eupatilin causes apoptosis. The treatment significantly upregulated the mRNA expression of p53, p21, and p27, causing cell cycle arrest in the G1 phase. Administration of eupatilin inhibited migration and invasion of the cells by downregulating the expression of Twist, Slug and MMP-2, -7. In addition, the agent increased protein expression of tumor suppressor PTEN, while transcription factor NF-κB expression was reduced.

CONCLUSION

Eupatilin strongly prevents the proliferation of prostate cancer cells, and suppresses migration and invasion. Due to its therapeutic potential, the clinical use of eupatilin in prostate cancer should also be supported by in vivo studies.

Quercetin Improves Inflammation, Oxidative Stress, and Impaired Wound Healing in Atopic Dermatitis Model of Human Keratinocytes

Background: Atopic dermatitis (AD) is a common inflammatory skin disease with complex pathogenesis. Natural flavonoids exhibit strong anti-inflammatory and antioxidant properties in many human diseases. In this study, the potential bioactive effect of quercetin, a polyphenolic plant-derived flavonoid, on the AD model of human keratinocytes was evaluated. Methods: Immortalized human HaCaT keratinocytes were treated with interleukin (IL) -4, -13, and tumor necrosis factor-α to mimic AD features in vitro. Then effects of quercetin on inflammation, oxidative stress, and wound healing were assessed. Results: Pretreatment of the cells with 1.5 μM of quercetin significantly reduced the expression of AD-induced IL-1β, IL-6, IL-8, and thymic stromal lymphopoietin, while it strongly enhanced the expression of superoxide dismutase-1 (SOD1), SOD2, catalase, glutathione peroxidase, and IL-10. Quercetin promoted wound healing by inducing epithelial-mesenchymal transition, which was supported by the upregulation of Twist and Snail mRNA expression. Unexpectedly, quercetin pretreatment of AD-induced cells upregulated the mRNA expression of occludin and E-cadherin, while downregulating matrix metalloproteinase 1 (MMP1), MMP2, and MMP9 expression. The pretreatment inhibited AD-induced phosphorylation of extracellular signal-regulated kinase 1/2/mitogen-activated protein kinase (ERK1/2 MAPK) and the expression of nuclear factor-kappa B (NF-κB), but it did not alter signal transducer and activator of transcription 6 (STAT6) phosphorylation. Conclusion: Quercetin may serve as a potential bioactive substance for atopic dermatitis-related symptoms through anti-inflammatory and antioxidant activities along with its acceleration of wound healing via ERK1/2 MAPK and NF-κB pathways.

The flavonoid apigenin reduces prostate cancer CD44(+) stem cell survival and migration through PI3K/Akt/NF-κB signaling

AIMS

Cancer stem cells (CSCs) are involved in drug resistance, metastasis and recurrence of cancers. The efficacy of apigenin on cell survival, apoptosis, migration and stemness properties were analyzed in CSCs.

MAIN METHODS

Prostate CSCs (CD44(+)) were isolated from human prostate cancer (PCa) PC3 cells using a magnetic-activated cell sorting system. PC3 and CSCs were treated with various concentrations of apigenin, docetaxel and their combinations for 48h.

KEY FINDINGS

Apigenin dose dependently inhibited CSCs and PC3 cell survival, and this was accompanied with a significant increase of p21 and p27. Apigenin induced apoptosis via an extrinsic caspase-dependent pathway by upregulating the mRNA expressions of caspases-8, -3 and TNF-α, but failed to regulate the intrinsic pathway as determined by the Bax, cytochrome c (Cyt-c) and APAF-1 in CSCs. In contrary to CSCs, apigenin induced intrinsic apoptosis pathway as evidenced by the induction of Bax, Cyt-c and caspase-3 while caspase-8, TNF-α and Bcl-2 levels remained unchanged in PC3 cells. The flavonoid strongly suppressed the migration rate of CSCs compared to untreated cells. Significant downregulation of matrix metallopeptidases-2, -9, Snail and Slug exhibits the ability of apigenin treatment to suppress invasion. The expressions of NF-κB p105/p50, PI3K, Akt and the phosphorylation of pAkt were decreased after apigenin treatment. Moreover, apigenin treatment significantly reduced pluripotency marker Oct3/4 protein expression which might be associated with the down-regulation of PI3K/Akt/NF-κB signaling.

SIGNIFICANCE

Our data indicated that, apigenin could be a useful compound to prevent proliferation and migration of cancer cells as well as CSCs.