A Morpholine Derivative N-(4-Morpholinomethylene)ethanesulfonamide Induces Ferroptosis in Tumor Cells by Targeting NRF2.

Small molecule drugs containing morpholine-based moieties have become crucial candidates in the tumor targeted therapy strategies, but the specific molecular mechanisms of these drugs causing tumor cell death require further investigation. The morpholine derivative N-(4-morpholinomethylene)ethanesulfonamide (MESA) was used to stimulate prostate and ovarian cancer cells and we focused on the ferroptosis effects, including the target molecule and signal pathways mediated by MESA. The results showed that MESA could induce ferroptosis to cause the proliferation inhibition and apoptosis effects of tumor cells according to the identification of ferroptosis inhibitor fer-1 and other cell death inhibitors. Further MESA could significantly increase the intracellular malondialdehyde (MDA), reactive oxygen species (ROS) and Fe2+ levels in tumor cells and mediate the dynamic changes of ferroptosis-relative molecules GPX4, nuclear factor erythroid2-related factor 2 (NRF2), ACSL4, SLC7A11 and P62-Kelch-like ECH-associated protein 1 (KEAP1)-NRF2-antioxidant response element (ARE) signal pathways. Further, NRF2 overexpression could reduce the tumor cell death and ROS levels exposure to MESA. Most importantly, it was confirmed that MESA could bind to NRF2 protein through molecular docking and thermal stability assays and NRF2 was a target molecule of MESA for inducing ferroptosis effects in tumor cells. Collectively, our findings indicated the ferroptosis effects of the morpholine derivative MESA in prostate and ovarian cancer cells and its function mechanism including targeted molecule and signal pathways, which would be helpful for developing MESA as a prospective small molecule drug for cancer therapy based on cell ferroptosis.

Radiotherapy Metastatic Prostate Cancer Cell Lines Treated with Gold Nanorods Modulate miRNA Signatures.

MicroRNA (miRNA) modulation has been identified as a promising strategy for improving the response of human prostate cancer (PCa) to radiotherapy (RT). Studies have shown that mimics or inhibitors of miRNAs could modulate the sensitivity of PCa cells to RT. In addition, pegylated gold nanoparticles have been studied as a therapeutic approach to treat PCa cells and/or vehicles for carrying miRNAs to the inside of cells. Therefore, we evaluated the capacity of hypofractionated RT and pegylated gold nanorods (AuNPr-PEG) to modulate the miRNA signature on PCa cells. Thus, RT-qPCR was used to analyze miRNA-95, miRNA-106-5p, miRNA-145-5p, and miRNA-541-3p on three human metastatic prostate cell lines (PC3, DU145, and LNCaP) and one human prostate epithelial cell line (HprEpiC, a non-tumor cell line) with and without treatment. Our results showed that miRNA expression levels depend on cell type and the treatment combination applied using RT and AuNPr-PEG. In addition, cells pre-treated with AuNPr-PEG and submitted to 2.5 Gy per day for 3 days decreased the expression levels of miRNA-95, miRNA-106, miRNA-145, and miRNA-541-3p. In conclusion, PCa patients submitted to hypofractionated RT could receive personalized treatment based on their metastatic cellular miRNA signature, and AuNPr-PEG could be used to increase metastatic cell radiosensitivity.

[Pyroptosis in the development and progression of prostate cancer: Progress in research].

Pyroptosis, as a new programmed death mode, plays an important role in the development and progression of prostate cancer, and the drugs targeting the pyroptosis pathway, as a new therapeutic strategy, may produce a significant influence on the treatment of prostate cancer . However, the precise mechanism of cellular pyroptosis remains unclear, necessitating further investigation. This paper presents a summary of the role of cellular pyroptosis in prostate cancer over recent years. It includes a discussion of the mechanism of pyroptosis, its role in prostate cancer development, and its clinical applications. This will provide clinicians with a new strategy for treatment and drug development.

The synthesis of novel water-soluble zinc (II) phthalocyanine based photosensitizers and exploring of photodynamic therapy activities on the PC3 cancer cell line.

In this study, Schiff base substituted phthalocyanine complexes (Zn1c, Zn2c) and their quaternized derivatives (Q-Zn1c, Q-Zn2c) were synthesized for the first time. Their structures have been characterized by FT-IR, 1H-NMR, UV-Vis, mass spectrometry and elemental analysis as well as. The photophysicochemical properties (fluorescence, singlet oxygen and photodegradation quantum yield) of these novel complexes were investigated in dimethylsulfoxide (DMSO) for both non-ionic and quaternized cationic phthalocyanine complexes and in aqueous solution for quaternized cationic phthalocyanine complexes. Water soluble cationic phthalocyanine compounds gave good singlet oxygen quantum yield (0.65 for Q-Zn1c, 0.66 for Q-Zn2c in DMSO; 0.65 for Q-Zn2c in aqueous solution). The binding of Q-Zn1c and Q-Zn2c to BSA/DNA was studied by using UV-Vis and fluorescence spectroscopy and these. Studies indicate that the mechanism of BSA quenching by quaternized zinc(II) phthalocyanines was static quenching. Quaternized zinc(II) phthalocyanines interacted with ct-DNA by intercalation. Quaternized zinc(II) phthalocyanines caused a decrease in cell viability and triggered apoptotic cell death after PDT was applied at a concentration that did not have a toxic effect on their own. Q-Zn1c and Q-Zn2c mediated PDT reduced the activity of SOD, CAT, GSH while increased MDA level in the prostate cancer cells. Furthermore, expression of apoptotic proteins after PDT was examined. The results revealed that the synthesized water soluble quaternized zinc(II) phthalocyanine complexes (Q-Zn1c and Q-Zn2c) are promising potential photosensitizers for PDT.

Extracellular Regucalcin Suppresses the Growth, Migration, Invasion, and Adhesion of Metastatic Human Prostate Cancer Cells.

INTRODUCTION: Regucalcin plays a multifunctional role in the regulation of cellular function including metabolism, signaling process, and transcriptional activity in maintaining cell homeostasis. Downregulated expression or activity of regucalcin contributes to the development of malignancies in various types of human cancer. Survival of cancer patients, including metastatic prostate cancer, is prolonged with high expression of regucalcin in the tumor tissues. METHODS: We elucidate whether extracellular regucalcin conquers the growth, migration, invasion, and adhesion of metastatic human prostate cancer PC-3 and DU-145 cells. RESULTS: Extracellular regucalcin (0.1, 1, and 10 nM) of physiologic levels (1 nM at human serum) inhibited colony formation and growth of PC-3 and DU-145 cells, while it did not have an effect on cell death. Repressive effects of extracellular regucalcin on the proliferation were not exhibited by the presence of inhibitors of the cell cycle, intracellular signaling process, and transcriptional activity, suggesting that the signals of extracellular regucalcin are transmitted to block cell growth. Furthermore, extracellular regucalcin (0.1, 1, or 10 nM) inhibited migration, invasion, and adhesion of PC-3 and DU-145 cells. Mechanistically, extracellular regucalcin (10 nM) decreased the levels of various signaling proteins including Ras, posphatidylinositol-3 kinase, mitogen-activated protein kinase, mechanistic target of rapamycin, RSK-2, caveolin-1, and integrin ß1 in PC-3 cells. DISCUSSION AND CONCLUSION: Thus, extracellular regucalcin may play a suppressive role in growth, migration, invasion, and adhesion, which are involved in the metastatic activity of human prostate cancer cells, via affecting diverse signaling processes. This study may provide a new strategy in preventing metastatic prostate cancer with exogenous regucalcin.

Paclitaxel Induces the Apoptosis of Prostate Cancer Cells via ROS-Mediated HIF-1α Expression.

Prostate cancer (PCa) is the most common malignancy to endanger the health of male genitourinary system. Clinically, paclitaxel (PTX) (C47H51NO14), a diterpene alkaloid, is commonly used as an effective natural antineoplastic drug during the treatment of PCa. However, the mechanism and pathway involved in the function of PTX are poorly understood. In the current study, we employed the CCK-8 assay, revealing that PTX can inhibit the survival and induce the apoptosis of PC3M cells (a human prostate cancer cell line) in a concentration-dependent manner. Reactive oxygen species (ROS), as a metabolic intermediate produced by the mitochondrial respiratory chain, are highly accumulated under the PTX treatment, which results in a sharp decrease of the mitochondrial membrane potential in PC3M cells. Additionally, the migration and invasion of PC3M cells are weakened due to PTX treatment. Further analysis reveals that N-acetylcysteine (NAC), which functions as an antioxidant, not only rescues the decreased mitochondrial membrane potential induced by the abnormal ROS level, but also restores the migration and invasion of PC3M cells. In a subsequent exploration of the detailed mechanism, we found that hypoxia-inducible factor (HIF)-1α works as a downstream gene that can respond to the increased ROS in PC3M cells. Under PTX treatment, the expression levels of HIF-1α mRNA and protein are significantly increased, which stimulate the activation of JNK/caspase-3 signaling and promote the apoptosis of PC3M cells. In summary, we demonstrate that PTX regulates the expression of HIF-1α through increased ROS accumulation, thereby promoting the activation of JNK/caspase-3 pathway to induce the apoptosis of PCa cells. This study provides new insights into the mechanism of antineoplastic action of taxanes and unveils the clinical benefit of the ROS-HIF-1α signaling pathway, which may offer a potential therapeutic target to prevent the development of PCa.

Active Ingredients from Euodia ruticarpa Steam Distilled Essential Oil Inhibit PC-3 Prostate Cancer Cell Growth via Direct Action and Indirect Immune Cells Conditioned Media In Vitro.

Active constituents isolated from Euodia ruticarpa (ER) steam distilled essential oil (SDEO) against PC-3 prostate cancer cell growth remain unclear. To clarify the puzzle, ER SDEO was extracted and further resolved into six isolated fractions ERF1-F6 with Sephadex LH-20 gel filtration chromatography to analyze their biological activities. Active ingredients in the isolated fractions were analyzed with GC-MS. Potential isolated fractions were selected to treat PC-3 cells with direct action and indirect treatment by mouse splenocyte- (SCM) and macrophage-conditioned media (MCM). The relationship between PC-3 cell viabilities and corresponding total polyphenols, flavonoid contents as well as Th1/Th2 cytokine profiles in SCM was analyzed using the Pearson product-moment correlation coefficient (r). As a result, ERF1-F3 was abundant in total polyphenols and flavonoids contents with diverse active ingredients. Treatments with ERF1-F3 at appropriate concentrations more or less inhibit PC-3 cell growth in a direct action manner. Only SCM, respectively, cultured with ER SDEO and ERF1-F3 markedly enhanced the effects to inhibit PC-3 cell growth, suggesting that secretions by splenocytes might involve anti-PC-3 effects. There are significantly negative correlations between PC-3 cell viabilities and IL-2, IL-10 as well as IL-10/IL-2 ratios in the corresponding SCM. Total polyphenol and flavonoid contents in the media cultured with ER SDEO isolated fractions positively correlated with IL-10 (Th2) and IL-10/IL-2 (Th2/Th1) cytokine secretion ratios by splenocytes, indicating that polyphenol and flavonoid components in ER SDEO isolated fractions promote Th2-polarized and anti-inflammatory characteristics. These new findings concluded that the inhibitory effects against PC-3 prostate cancer cell growth are attributed to active anti-inflammatory ingredients in ER SDEO and its active ERF1-F3 fractions through direct action and indirect treatment by modulating splenocytes' cytokine secretion profiles.

Chemical constituents from basidiomycete Basidioradulum radula culture medium and their cytotoxic effect on human prostate cancer DU-145 cells.

Eight new naphtho[1,2-c]furan derivatives (1-8) along with six known analogues (9-14) were isolated from culture medium of the basidiomycete Basidioradulum radula. The structures of these compounds were identified using spectroscopic analysis, and their absolute configurations were resolved using X-ray diffraction, ECD, and VCD. Compounds 7 and 14 inhibited the cell viability of human prostate cancer DU-145 cells with IC50 values of 7.54 ± 0.03 µM and 5.04 ± 0.03 µM, respectively. At 8 µM, compounds 7 and 14 increased the percentage of apoptotic cells and upregulated the protein expression related to the apoptosis caspase pathways in DU-145 cells. Furthermore, the hallmarks of cells undergoing apoptosis, such as chromatin condensation, were also observed at this concentration. However, compound 7 and 14 showed no effect on the proliferation of splenocytes isolated from cyclophosphamide-induce immunosuppressed mice.

Preparation of Catechin Nanoemulsion from Oolong Tea Leaf Waste and Its Inhibition of Prostate Cancer Cells DU-145 and Tumors in Mice.

Anti-cancer activity of catechin nanoemulsions prepared from Oolong tea leaf waste was studied on prostate cancer cells DU-145 and DU-145-induced tumors in mice. Catechin nanoemulsions composed of lecithin, Tween-80 and water in an appropriate proportion was prepared with high stability, particle size of 11.3 nm, zeta potential of -67.2 mV and encapsulation efficiency of 83.4%. Catechin nanoemulsions were more effective than extracts in inhibiting DU-145 cell growth, with the IC50 being 13.52 and 214.6 µg/mL, respectively, after 48 h incubation. Furthermore, both catechin nanoemulsions and extracts could raise caspase-8, caspase-9 and caspase-3 activities for DU-145 cell apoptosis, arresting the cell cycle at S and G2/M phases. Compared to control, catechin nanoemulsion at 20 µg/mL and paclitaxel at 10 µg/mL were the most effective in reducing tumor volume by 41.3% and 52.5% and tumor weight by 77.5% and 90.6% in mice, respectively, through a decrease in EGF and VEGF levels in serum.

Exploring the impact of a naturally occurring sapogenin diosgenin on underlying mechanisms of Ca2+ movement and cytotoxicity in human prostate cancer cells.

Literature has shown that diosgenin, a naturally occurring sapogenin, inducedcytotoxic effects in many cancer models. This study investigated the effect of diosgenin on intracellular Ca2+ concentration ([Ca2+ ]i) and cytotoxicity in PC3 human prostate cancer cells. Diosgenin (250-1000 µM) caused [Ca2+ ]i rises which was reduced by Ca2+ removal. Treatment with thapsigargin eliminated diosgenin-induced [Ca2+ ]i increases. In contrast, incubation with diosgeninabolished thapsigargin-caused [Ca2+ ]i increases. Suppression of phospholipase C with U73122 eliminated diosgenin-caused [Ca2+ ]i increases. Diosgenin evoked Mn2+ influx suggesting that diosgenin induced Ca2+ entry. Diosgenin-induced Ca2+ influx was suppressed by PMA, GF109203X, and nifedipine, econazole, or SKF96365. Diosgenin (250-600 µM) concentration-dependently decreased cell viability. However, diosgenin-induced cytotoxicity was not reversed by chelation of cytosolic Ca2+ with BAPTA/AM. Together, diosgenin evoked [Ca2+ ]i increases via Ca2+ release and Ca2+ influx, and caused Ca2+ -non-associated deathin PC3 cells. These findings reveal a newtherapeutic potential of diosgenin for human prostate cancer.

Optimized synthesis and antiproliferative activity of desTHPdactylolides.

Dactylolide and certain analogues are attractive targets for study due to their structural resemblance to zampanolide, a very promising anticancer lead compound and a unique covalent-binding microtubule stabilizing agent. The primary goal of this project is identification and synthesis of simplified analogues of dactylolide that would be easier to prepare and could be investigated for antiproliferative activity in comparison with zampanolide. Extension of Almann's concept of a simplified zampanolide analogue to dactylolide in the form of desTHPdactylolide was attractive not only for reasons of synthetic simplification but also for the prospect that analogues of dactylolide could be prepared in both (17S) and (17R) configurations. Since Altmann's overall yield for the six-step procedure leading to the C9-C18 fragment of desTHPdactylolide was only 8.7%, a study focused on optimized synthesis and antiproliferative evaluation of each enantiomer of desTHPdactylolide was initiated using Altmann's route as a framework. To this end, two optimized approaches to this fragment C9-C18 were successfully developed by us using allyl iodide or allyl tosylate as the starting material for a critical Williamson ether synthesis. Both (17S) and (17R) desTHPdactylolides were readily synthesized in our laboratory using optimized methods in yields of 37-43%. Antiproliferative activity of the pair of enantiomeric desTHPdactylolides, together with their analogues, was evaluated in three docetaxel-sensitive and two docetaxel-resistant prostate cancer cell models using a WST-1 cell proliferation assay. Surprisingly, (17R) desTHPdactylolide was identified as the eutomer in the prostate cancer cell models. It was found that (17S) and (17R) desTHPdactylolide exhibit equivalent antiproliferative potency towards both docetaxel-sensitive (PC-3 and DU145) and docetaxel-resistant prostate cancer cell lines (PC-3/DTX and DU145/DTX).

Expression, localisation and potential significance of aquaporins in benign and malignant human prostate tissue.

BACKGROUND: To study the expression pattern, localisation and potential clinical significance of aquaporin water channels (AQP) both in prostate cancer (PC) cell lines and in benign and malignant human prostate tissue. METHODS: The AQP transcript and protein expression of HPrEC, LNCaP, DU-145 and PC3 cell lines was investigated using reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence (IF) microscopy labelling. Immunohistochemistry (IHC) was performed to assess AQP protein expression in surgical specimens of benign prostatic hyperplasia as well as in PC. Tissue mRNA expression of AQPs was quantified by single-step reverse transcriptase quantitative polymerase chain reaction (qPCR). Relative gene expression was determined using the 40-ΔCT method and correlated to clinicopathological parameters. RESULTS: Transcripts of AQP 1, 3, 4, 7, 8, 10 and 11 were expressed in all four cell lines, while AQP 9 transcripts were not detected in malignant cell lines. IF microscopy confirmed AQP 3, 4, 5, 7 and 9 protein expression. IHC revealed highly heterogeneous AQP 3 protein expression in PC specimens, with a marked decrease in expression in tumours of increasing malignancy. Loss of AQP 9 was shown in PC specimens. mRNA expression of AQP3 was found to be negatively correlated to PSA levels (ρ = - 0.354; p = 0.013), D'Amico risk stratification (ρ = - 0.336; p = 0.012), ISUP grade (ρ = - 0.321; p = 0.017) and Gleason score (ρ = - 0.342; p = 0.011). CONCLUSIONS: This is the first study to systematically characterize human prostate cell lines, benign prostatic hyperplasia and PC in relation to all 13 members of the AQP family. Our results indicate the differential expression of several AQPs in benign and malignant prostate tissue. A significant correlation was observed between AQP 3 expression and tumour grade, with progressive loss in more malignant tumours. Taken together, AQPs may play a role in the progression of PC and AQP expression patterns may serve as a prognostic marker.

Biological Potential and Mechanism of Prodigiosin from Serratia marcescens Subsp. lawsoniana in Human Choriocarcinoma and Prostate Cancer Cell Lines.

Tripyrrole molecules have received renewed attention due to reports of numerous biological activities, including antifungal, antibacterial, antiprotozoal, antimalarial, immunosuppressive, and anticancer activities. In a screen of bacterial strains with known toxicities to termites, a red pigment-producing strain, HDZK-BYSB107, was isolated from Chamaecyparis lawsoniana, which grows in Oregon, USA. Strain HDZK-BYSB107 was identified as Serratia marcescens subsp. lawsoniana. The red pigment was identified as prodigiosin using ultraviolet absorption, LC-MS, and 1H-NMR spectroscopy. The bacterial prodigiosin had an inhibitory effect on both Gram-negative and Gram-positive bacteria. The main objective of this study was to explore the anticancer activities and mechanism of strain HDZK-BYSB107 prodigiosin by using human choriocarcinoma (JEG3) and prostate cancer cell lines (PC3) in vitro and JEG3 and PC3 tumor-bearing nude mice in vivo. In vitro anticancer activities showed that the bacterial prodigiosin induced apoptosis in JEG3 cells. In vivo anticancer activities indicated that the prodigiosin significantly inhibited the growth of JEG3 and PC3 cells, and the inhibitory activity was dose and time dependent. The anticancer efficacy of the bacterial prodigiosin on JEG3 and PC3 cells, JEG3 and PC3 tumor exhibited a correlation with the down regulation of the inhibitor of IAP family, including XIAP, cIAP-1 and cIAP-2, and the activation of caspase-9 and caspase-3 accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. The expressions of P53 and Bax/Bcl-2 in JEG3 and PC3 cells were significantly higher than in untreated groups. Our results indicated that the bacterial prodigiosin extracted from C. lawsoniana is a promising molecule due to its potential for therapeutic applications.

RNA splicing and splicing regulator changes in prostate cancer pathology.

Changes in mRNA splice patterns have been associated with key pathological mechanisms in prostate cancer progression. The androgen receptor (abbreviated AR) transcription factor is a major driver of prostate cancer pathology and activated by androgen steroid hormones. Selection of alternative promoters by the activated AR can critically alter gene function by switching mRNA isoform production, including creating a pro-oncogenic isoform of the normally tumour suppressor gene TSC2. A number of androgen-regulated genes generate alternatively spliced mRNA isoforms, including a prostate-specific splice isoform of ST6GALNAC1 mRNA. ST6GALNAC1 encodes a sialyltransferase that catalyses the synthesis of the cancer-associated sTn antigen important for cell mobility. Genetic rearrangements occurring early in prostate cancer development place ERG oncogene expression under the control of the androgen-regulated TMPRSS2 promoter to hijack cell behaviour. This TMPRSS2-ERG fusion gene shows different patterns of alternative splicing in invasive versus localised prostate cancer. Alternative AR mRNA isoforms play a key role in the generation of prostate cancer drug resistance, by providing a mechanism through which prostate cancer cells can grow in limited serum androgen concentrations. A number of splicing regulator proteins change expression patterns in prostate cancer and may help drive key stages of disease progression. Up-regulation of SRRM4 establishes neuronal splicing patterns in neuroendocrine prostate cancer. The splicing regulators Sam68 and Tra2ß increase expression in prostate cancer. The SR protein kinase SRPK1 that modulates the activity of SR proteins is up-regulated in prostate cancer and has already given encouraging results as a potential therapeutic target in mouse models.

Modulation of the sphingolipid rheostat is involved in paclitaxel resistance of the human prostate cancer cell line PC3-PR.

Taxoids are anti-cancer drugs frequently used to treat solid tumors, but they are sometimes ineffective and tumors may become resistant to their action. Here, we examined the involvement of sphingolipid metabolic enzymes in paclitaxel (PTX) resistance using a human prostate cancer cell line, PC3, and its PTX-resistant subline, PC3-PR. PTX (20 nM) suppressed cell proliferation and increased various ceramide species in PC3, but not PC3-PR, cells. PC3-PR contained higher S1P levels than did PC3, regardless of PTX treatment. Western blotting revealed that PC3-PR cells expressed higher levels of sphingosine kinase 1 (SPHK1) and glucosylceramide synthase (GCS) but lower levels of acid sphingomyelinase (ASMase) and neutral sphingomyelinase 2 than did PC3 cells. Inhibition of SPHK1 using siRNA or a pharmacological inhibitor decreased S1P levels in PC3-PR cells and inhibited proliferation in the presence or absence of PTX, suggesting that SPHK1 is at least partially responsible for PTX resistance. Similarly, GCS inhibitors (PDMP and PPMP) increased cellular ceramides and suppressed the proliferation of PC3-PR. However, inhibition of proteasome function or histone deacetylase activity increased SMase and ceramide levels and suppressed PC3-PR proliferation. These results suggest that modulation of metabolic enzyme expression and alteration of the sphingolipid rheostat protects cancer cells against PTX.

Silk scaffolds connected with different naturally occurring biomaterials for prostate cancer cell cultivation in 3D.

In the present work, different biopolymer blend scaffolds based on the silk protein fibroin from Bombyx mori (BM) were prepared via freeze-drying method. The chemical, structural, and mechanical properties of the three dimensional (3D) porous silk fibroin (SF) composite scaffolds of gelatin, collagen, and chitosan as well as SF from Antheraea pernyi (AP) and the recombinant spider silk protein spidroin (SSP1) have been systematically investigated, followed by cell culture experiments with epithelial prostate cancer cells (LNCaP) up to 14 days. Compared to the pure SF scaffold of BM, the blend scaffolds differ in porous morphology, elasticity, swelling behavior, and biochemical composition. The new composite scaffold with SSP1 showed an increased swelling degree and soft tissue like elastic properties. Whereas, in vitro cultivation of LNCaP cells demonstrated an increased growth behavior and spheroid formation within chitosan blended scaffolds based on its remarkable porosity, which supports nutrient supply matrix. Results of this study suggest that silk fibroin matrices are sufficient and certain SF composite scaffolds even improve 3D cell cultivation for prostate cancer research compared to matrices based on pure biomaterials or synthetic polymers.

Design, Synthesis, and Cytotoxic Evaluation of Certain 7-Chloro-4-(piperazin-1-yl)quinoline Derivatives as VEGFR-II Inhibitors.

Signaling pathway inhibition of VEGFR-II is visualized as valuable tool in cancer management. In the current study, the synthesis of novel 1-4-(7-chloroquinolin-4-yl)piperazin-1-yl)-2-(N-substituted-amino)-ethanone derivatives (4a-t) was achieved through the amination of 2-chloro-1-(4-(7-chloroquinolin-4-yl)piperazin-1-yl)ethanone (3) with different secondary amines. The structures of the target compounds were confirmed by IR, 1 H-NMR, 13 C-NMR, HRMS, and microanalysis. Compounds 4a-t were subjected to in vitro anticancer screening against human breast cancer (MCF-7) and prostate cancer (PC3) cell lines. The highest cytotoxicty against both cell lines was displayed by 2-(4-(4-bromobenzyl)piperazin-1-yl)-1-(4-(7-chloroquinolin-4-yl)piperazin-1-yl)ethanone (4q), with IC50 values of 6.502 and 11.751 µM against MCF-7 and PC3 cells, respectively, compared with the standard drug doxorubicin (MCF-7: 6.774 µM, PC3: 7.7316 µM). Due to its notable activity toward MCF-7 cells, 4q was further evaluated as VEGFR-II inhibitor, showing an IC50 of 1.38 µM compared to sorafenib (0.33 µM). The docking study proved that 4q has a binding mode akin to that of VEGFR-II inhibitors.

The Prostate Cancer Cells Resistant to Docetaxel as in vitro Model for Discovering MicroRNAs Predictive of the Onset of Docetaxel Resistance.

On the grounds that miRNAs present in the blood of prostate cancer (PCa) patients are released in the growth medium by PCa cells, it is conceivable that PCa cells resistant to docetaxel (DCT) (DCTR) will release miRNAs that may be found in PCa patients under DCT therapy if resistant PCa cells appear. We isolated DCTR clones respectively from 22Rv1 and DU-145 PCa cell lines and performed through next-generation sequencing (NGS) the miRNAs profiles of the released miRNAs. The analysis of the NGS data identified 105 and 1 miRNAs which were differentially released in the growth medium of the 22Rv1/DCTR and DU-145/DCTR clones, respectively. Using additional filters, we selected 12 and 1 miRNA more released by all 22Rv1/DCTR and DU-145/DCTR clones, respectively. Moreover, we showed that 6 of them were more represented in the growth medium of the DCTR cells than the ones of DCT-treated cells. We speculated that they have the pre-requisite to be tested as predictive biomarkers of the DCT resistance in PCa patients under DCT therapy. We propose the utilization of clones resistant to a given drug as in vitro model to identify the differentially released miRNAs, which in perspective could be tested as predictive biomarkers of drug resistance in tumor patients under therapy.

Quantitative phosphoproteomics reveals the protein tyrosine kinase Pyk2 as a central effector of olfactory receptor signaling in prostate cancer cells.

The prostate-specific G-protein-coupled receptor 1 (PSGR1) is an olfactory receptor specifically expressed in the prostate gland. PSGR1 expression is elevated both in benign prostatic hyperplasia tissue and in prostate cancer. Stimulation of PSGR1 by the odorant ß-ionone leads to an increase in the intracellular Ca(2+) concentration, activation of mitogen-activated protein (MAP) kinases and a decrease in prostate cancer cell proliferation. To further extend our knowledge about PSGR1 signaling in prostate cancer cells, we performed a quantitative phosphoproteomics study using stable isotope labeling by amino acids in cell culture and mass spectrometry. We report 51 differentially regulated phosphorylation sites in 24 proteins with functions in cytoskeletal remodeling, signaling and ion transport. Activation of PSGR1 evoked an increase in intracellular pH mediated by the sodium/hydrogen exchanger NHE1. Furthermore, we report the protein tyrosine kinase Pyk2 as a central effector of PSGR1 signaling cascades in LNCaP cells. Our data show that phosphorylation of p38 MAP kinase is triggered by Pyk2. In addition, we confirmed dephosphorylation of the tumor suppressor protein N-myc downstream regulated gene 1 (NDRG1) at Ser330 downstream of Pyk2. Since NDRG1 impacts oncogenic signaling pathways interfering with tumor progression, we suggest that the Pyk2-NDRG1 axis is possibly involved in conveying the anti-proliferative effect of ß-ionone in prostate cancer cells. This article is part of a Special Issue entitled: Medical Proteomics.

Mechanism of paclitaxel resistance in a human prostate cancer cell line, PC3-PR, and its sensitization by cabazitaxel.

Paclitaxel (PTX) is a microtubule-targeting drug widely used for the treatment of a variety of cancers. However, drug resistance can emerge after a series of treatments, and this can seriously affect the patient's prognosis. Here, we analyzed the mechanism of PTX resistance using a human prostate cancer cell line, PC3, and its PTX-resistant subline, PC3-PR. Compared with PC3, PC3-PR exhibited some unique phenotypes that might be associated with PTX resistance, including decreased expression of acetylated α-tubulin and the cell cycle regulator p21, and increased expression of ßIII tubulin, histone deacetylase 6 (HDAC6), and the anti-apoptotic protein Bcl2. The drug exporters MDR1 and MRP1 were not involved in PTX resistance. Although cabazitaxel (CTX), a novel taxoid, has been reported to overcome PTX resistance, its mechanism of action is unknown. We found that treatment of PC3-PR cells with CTX induced expression of acetylated α-tubulin and p21, but not the related regulators p27, p15, and p16 or the Bcl2 family proteins. The pan-HDAC inhibitors trichostatin A and suberanilohydroxamic acid and the HDAC6-specific inhibitor tubacin inhibited PC3-PR proliferation and increased expression of p21 and acetylated α-tubulin in a manner similar to CTX. Our data shed light on the cellular response to PTX and CTX.