Two new guanidine alkaloids, batzelladines O (
) and P (
), were isolated from the deep-water marine sponge
The structures of these metabolites were determined by NMR spectroscopy, mass spectrometry, ...and ECD. The isolated compounds exhibited cytotoxic activity in human prostate cancer cells PC3, PC3-DR, and 22Rv1 at low micromolar concentrations and inhibited colony formation and survival of the cancer cells. Batzelladines O (
) and P (
) induced apoptosis, which was detected by Western blotting as caspase-3 and PARP cleavage. Additionally, induction of pro-survival autophagy indicated as upregulation of LC3B-II and suppression of mTOR was observed in the treated cells. In line with this, the combination with autophagy inhibitor 3-methyladenine synergistically increased the cytotoxic activity of batzelladines O (
) and P (
). Both compounds were equally active in docetaxel-sensitive and docetaxel-resistant prostate cancer cells, despite exhibiting a slight p-glycoprotein substrate-like activity. In combination with docetaxel, an additive effect was observed. In conclusion, the isolated new guanidine alkaloids are promising drug candidates for the treatment of taxane-resistant prostate cancer.
Marine alkaloid fascaplysin and its derivatives are known to exhibit promising anticancer properties in vitro and in vivo. However, toxicity of these molecules to non-cancer cells was identified as a ...main limitation for their clinical use. Here, for the very first time, we synthesized a library of fascaplysin derivatives covering all possible substituent introduction sites, i.e., cycles A, C and E of the 12
-pyrido1-2-
:3,4-
'diindole system. Their selectivity towards human prostate cancer versus non-cancer cells, as well as the effects on cellular metabolism, membrane integrity, cell cycle progression, apoptosis induction and their ability to intercalate into DNA were investigated. A pronounced selectivity for cancer cells was observed for the family of di- and trisubstituted halogen derivatives (modification of cycles A and E), while a modification of cycle C resulted in a stronger activity in therapy-resistant PC-3 cells. Among others, 3,10-dibromofascaplysin exhibited the highest selectivity, presumably due to the cytostatic effects executed via the targeting of cellular metabolism. Moreover, an introduction of radical substituents at C-9, C-10 or C-10 plus C-3 resulted in a notable reduction in DNA intercalating activity and improved selectivity. Taken together, our research contributes to understanding the structure-activity relationships of fascaplysin alkaloids and defines further directions of the structural optimization.
The antiangiogenic agent cilengitide disrupts integrin binding to the extracellular matrix leading to apoptosis of activated endothelial cells. Integrins are also widely expressed in malignant glioma ...and integrin inhibitors may directly target tumor cells in this disease. Aim of the current study was to investigate effects of cilengitide on endothelial and glioma cells on molecular and cellular levels.
Cilengitide caused dose-dependent detachment of endothelial cells from cell culture dishes. Proliferation of endothelial cells was significantly inhibited while the proportion of apoptotic cells was increased. Incubation of integrin-expressing glioma cells with cilengitide caused rounding and detachment after 24 hours as observed with endothelial cells. Cilengitide inhibited proliferation and induced apoptosis in glioma cells with methylated MGMT promotor when given alone or in combination with temozolomide. In endothelial as well as glioma cells cilengitide inhibited phosphorylation of FAK, Src and Akt. Assembly of cytoskeleton and tight junctions was heavily disturbed in both cell types.
Cilengitide inhibits integrin-dependent signaling, causes disassembly of cytoskeleton, cellular detachment and induction of apoptosis in endothelial and glioma cells thereby explaining the profound activity of integrin inhibitors in gliomas. The combination of cilengitide with temozolomide exerted additive effects in glioma cells as observed clinically.
Treatment of castration-resistant prostate cancer (CRPC) remains challenging due to the development of drug resistance. The Warburg effect describes the ability of cancer cells to consume larger ...amounts of glucose compared to normal tissues. We identified derivatives of natural 1,4-naphthoquinones to be active in CRPC and further synthetically modified them via glucose conjugation to increase selectivity by Warburg effect targeting. Mechanisms of action were examined by quantitative proteomics followed by bioinformatical analysis and target validation. Four synthesized molecules revealed the highest selectivity towards human CRPC cells, which correlated with higher GLUT-1 activity and expression. The compounds were able to induce pro-apoptotic signs and to inhibit the pro-survival processes and mechanisms of drug resistance (i.e., AR-signaling and autophagy). Proteome analysis suggested a disruption of the mitochondria/oxidative phosphorylation, which was validated by further functional analysis: thus, mitochondria depolarization, elevated levels of cytotoxic ROS, an increase of Bax/Bcl-2 ratio as well as release of mitochondrial AIF and cytochrome C to cytoplasm were observed. In conclusion, glucose-conjugated 1,4-naphthoquinones show potent activity and selectivity in human CRPC exerted via mitochondrial targeting. The compounds can overcome drug resistance against current standard therapies and suppress pro-survival mechanisms. This unique combination of properties makes them new promising candidates for the treatment of CRPC.
Development of resistance to currently available standard therapies in advanced prostate cancer (PCa) emphasizes the need for novel therapeutic options. Here, we report the synthesis of new hybrid ...molecules consisting of 2-chloroethylthio and 1,4-naphthoquinone pharmacophores and describe their activity in PCa. In screening analyses, the introduction of one 2-chloroethylthio group improved the anticancer properties of 1,4-naphthoquinones, whereas the introduction of a second 2-chloroethylthio moiety rather decreased activity. Two most promising of the synthesized compounds, 30 and 32, were highly active in different human PCa cell lines harboring varying resistance profiles at nanomolar concentrations. The generated data suggest that the compounds are capable of mitochondria targeting, cytotoxic ROS induction, and DNA damage, which resulted in apoptosis presumably executed in a caspase-dependent manner. The substances synergized with the clinically approved PARP inhibitor olaparib and resensitized AR-V7-expressing PCa cells to antiandrogen enzalutamide, as well as to a combination of enzalutamide and an AKT inhibitor. This was at least in part exerted via down-regulation of AR-V7 expression and inhibition of AR signaling. Mild antagonism was observed in combination with platinum- or taxane-based chemotherapy, which was putatively related to treatment-induced activation of p38, JNK1/2, ERK1/2, MEK1/2, and AKT, functioning as potential pro-survival factors. Thus, the synthesized (2-chloroethylthio)-1,4-naphthoquinone derivatives exhibit promising anticancer properties in vitro, suggesting their further development as potential therapeutics for the treatment of castration-resistant PCa.
From a root bark of
Turch we isolated two new (7 and 8) and six previously known compounds (1-6) belonging to the group of prenylated polyphenols. Their structures were elucidated using mass ...spectrometry, nuclear magnetic resonance and circular dichroism spectroscopy. These natural compounds selectively inhibited human drug-resistant prostate cancer in vitro. Prenylated pterocarpans 1-3 prevented the cell cycle progression of human cancer cells in S-phase. This was accompanied by a reduced expression of mRNA corresponding to several human cyclin-dependent kinases (CDKs). In contrast, compounds 4-8 induced a G1-phase cell cycle arrest without any pronounced effect on CDKs mRNA expression. Interestingly, a non-substituted hydroxy group at C-8 of ring D of the pterocarpan skeleton of compounds 1-3 seems to be important for the CDKs inhibitory activity.
Abstract Background Patients with germ cell tumors (GCTs) receiving cisplatin-based chemotherapy are at increased risk of thrombosis, but the underlying cellular and molecular mechanisms remain ...obscure. Objective To study baseline tissue factor (TF) expression by GCT cell lines and its modulation by cisplatin treatment. Methods TF expression was assessed by single-stage clotting and thrombin generation assay, flow cytometry, ELISA, and Western blot analysis. Cell cycle analysis and detection of phosphatidylserine (PS) membrane exposure were carried out by flow cytometry. TF mRNA was analyzed by quantitative RT-PCR. Results Significant expression of TF-specific procoagulant activity (PCA) was detected on three non-seminoma (NT2, 2102Ep, NCCIT) and one seminoma cell line (TCam-2). Treatment with 0.4 μM cisplatin (corresponding to the IC50 ) for 48 hrs increased TF PCA on NT2 cells 3-fold, an effect that was largely independent of PS exposure and that could not be explained by translocation of active TF from intracellular storage pools. Cisplatin-induced TF PCA expression in NT2 cells did not occur before 12 hrs, but was steady thereafter and accompanied by a 2-fold increase in total and surface-located TF antigen. Importantly, increased TF gene transcription or production and release of an intermediate factor were not involved in this process. Cell cycle analysis suggested that cisplatin-induced G2/M arrest resulted in an accumulation of procoagulant TF on the membrane surface of NT2 cells. Conclusions In addition to induction of apoptosis/necrosis with PS-mediated activation of preformed TF, cisplatin may alter the procoagulant phenotype of GCT cells through an increase in total cellular TF antigen.
Natural language processing contains multiple methods of translating written text or spoken words into numerical information called word embeddings. Some of these embedding methods, such as Bag of ...Words, assume words are independent of one another. Other embedding methods, such as Bidirectional Encoder Representations from Transformers and Word2Vec, capture the relationship between words in various ways. In this paper, we are interested in comparing methods treating words as independent and methods capturing the relationship between words by looking at the effect these methods have on the classification of fake news. Using various classification methods, we compare the word embedding processes based on their effects on accuracy, precision, sensitivity, and specificity.
Here, we show that carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is expressed in umbrella cells of bladder urothelium but is down-regulated in superficial bladder cancer, such ...as histologic tumor stage a (pTa) and transitional cell carcinoma in situ (pTis). Concurrently, CEACAM1 is up-regulated in the endothelia of adjacent angiogenic blood vessels. Mimicking the CEACAM1 down-regulation in the urothelium, CEACAM1 was silenced in bladder cancer cell lines 486p and RT4 using the small interfering RNA technique. CEACAM1 down-regulation was confirmed at the protein level by Western blot analyses. CEACAM1 silencing leads to a significant up-regulation of vascular endothelial growth factor (VEGF)-C and VEGF-D in quantitative reverse transcription-PCR. Correspondingly, supernatants from the CEACAM1-overexpressing bladder cancer cell lines reduce, but those from CEACAM1 silencing induce endothelial tube formation and potentiate the morphogenetic effects of VEGF. These data suggest that the epithelial down-regulation of CEACAM1 induces angiogenesis via increased expression of VEGF-C and VEGF-D. Inversely, CEACAM1 is up-regulated in endothelial cells of angiogenic blood vessels. This in turn is involved in the switch from noninvasive and nonvascularized to invasive and vascularized bladder cancer. CEACAM1 appears to be a promising endothelial target for bladder cancer therapy.
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Background: Development of aggressive variants of metastatic castration-resistant prostate cancer (AVPC) is a major challenge in the course of therapy but the underlying mechanisms of aggressive ...transdifferentiation are not completely understood and appropriate tumor models are missing. Here, we investigated the consequences of long-term taxane exposure on hormone-independent, BRCA2-mutated, AR-V7-positive 22Rv1 cells. Methods: 22Rv1 cells were treated with stepwise increased taxane concentrations for 10 months. Individual clones were picked and further cultured in media containing either docetaxel (Doce) or cabazitaxel (Caba). Passage-matched cells were maintained in culture without treatment. Further characterization was carried out using proliferation, migration, metabolic, and colony formation assays as well as proteomics, RNAseq analyses and xenotransplantation in immunodeficient mice. Results: In total, three single cell 22Rv1-DR clones (50-100-fold resistance to Doce) and three 22Rv1-CR clones (80-150-fold resistance to Caba) were successfully established. All clones showed cross-resistance to either drug. Expectedly, treatment-induced overexpression of ABCB1 was detected and validated. Moreover, alteration of drug resistance related SLC7A5, SLC3A2, and SLC25A24 genes was observed. Additionally, an enrichment analyses identified, among others, neuroendocrine transdifferentiation (GO-term “Neuroendocrine tumors”, p=4.46e-5) to be stimulated in prostate 22Rv1 cells under long-term treatment with Doce or Caba. In line with this, the neuroendocrine features were validated in vitro as well as in xenotransplanted tumors in vivo with upregulation of synaptophysin, chromogranin and neuron specific enolase accompanied by downregulation of the androgen receptor (AR) and upregulation of AR spice variants. Additionally, neuritic morphology, shift to higher nuclear-plasma ratio, partial loss of adherent properties and growth slowdown, along with higher migratory activity were detected. Conclusions: Long-term taxane exposure of 22Rv1 cells resulted in the development of neuroendocrine traits in individual cell clones that have successfully been translated into stable cell lines. Thus, we provide a new cell line model for secondary therapy-induced neuroendocrine transdifferentiation. Further in-depth analysis to identify individual alterations in the course of therapy is currently ongoing.
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