The Combination of Omega-3 Stearidonic Acid and Docetaxel Enhances Cell Death over Docetaxel Alone in Human Prostate Cancer Cells (original) (raw)
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Journal of Cancer Research & Therapy, 2014
Doxorubicin (DOX) is a first choice cytostatic drug in treatment of many cancers but among its side effects is cardiac toxicity. Stearidonic omega-3 fatty acid (SDA) has cardiac protective qualities and, therefore, we investigated the combinatory effects of DOX and SDA on proliferation/viability in the human prostate cancer (PCa) cell lines LNCaP, PC3, and DU145 as well as possible modulatory effects on expression of androgen receptor (AR), peroxisome proliferator-activated receptor gamma (PPAR, and nuclear factor kappa-lightchain-enhancer of activated B cells (NF-B) nuclear transcription factors implicated in tumorigenesis. The median inhibitory effects (IC50) of SDA were 601, 116, 145 M and that of DOX were 802, 761, 363 nM in LNCaP, PC3 and DU145, respectively. Equipotent combinations of DOX and SDA based on 2-fold dilutions and constant combination ratios derived from the above IC50 values suggested anticancer synergism with a combination index (CI) of less than 1 as determined using the Chou-Talalay method based on the medianeffect equation and the mass action law. Stearidonic acid strongly inhibited TNF-activated NF-B in stably transduced LNCaP cells. We used immunocytochemistry, real-time PCR, western blotting, and transactivation assays to demonstrate inhibition of agonist-activated AR and PPAR expression following treatment with DOX and SDA singly or in combination. This study provides proof-of-concept for using DOX and SDA in combination to reduce dose and toxicity of DOX in PCa clinical translation studies.
Antiandrogen-induced cell death in LNCaP human prostate cancer cells
Cell Death and Differentiation, 2003
Antiandrogens such as Casodex (Bicalutamide) are designed to treat advance stage prostate cancer by interfering with androgen receptor-mediated cell survival and by initiating cell death. Treatment of androgen sensitive, non-metastatic LNCaP human prostate cancer cells with 0-100 lM Casodex or 0-10 ng/ml TNF-a induces cell death in 20-60% of the cells by 48 h in a dose-dependent manner. In cells treated with TNFa, this is accompanied by the loss of mitochondrial membrane potential (DW m ) and cell adhesion. In contrast, cells treated with Casodex display loss of cell adhesion, but sustained mitochondrial dehydrogenase activity. Overexpression of Bcl-2 in LNCaP cells attenuates the induction of cell death by TNF-a but not Casodex, suggesting that mitochondria depolarization is not required for the induction of cell death by Casodex. While both TNF-a and Casodex-induced release of cytochrome c in LNCaP cell is predominantely associated with the translocation and cleavage of Bax, our data also suggest that Casodex induces cell death by acting on components downstream of decline of DW m and upstream of cytochrome c release. Furthermore, while induction of both caspase-3 and caspase-8 activities are observed in TNF-a and Casodex-treated cells, a novel cleavage product of procaspase-8 is seen in Casodex-treated cells. Taken together, these data support the hypothesis that Casodex induces cell death by a pathway that is independent of changes in DW m and Bcl-2 actions and results in an extended lag phase of cell survival that may promote the induction of an invasive phenotype after treatment.
Cancer Research, 2008
Synthetic triterpenoids 2-cyano-3, 12-dioxooleana-1, 9-(11)dien-28-oic acid (CDDO) and CDDO-Me (CDDO-methyl ester) have entered clinical trials for cancer. We determined that CDDO analogues at submicromolar concentrations induce apoptosis of cultured prostate cancer cell lines, LNCaP, ALVA31, Du145, PC3, and PPC1, with lethal dose 50% f1 Mmol/L for CDDO-Me and an imidazole analogue (CDDO-Im). These compounds induced apoptosis of prostate cancer cells as characterized by cleavage of caspase-3, caspase-7, caspase-8, caspase-9, caspase-10, BID, and poly(ADP)ribose polymerase and by dependence on caspase activity. Moreover, triterpenoid-induced cell death was abolished by caspase-8targeting small interfering (si) RNA. To explore the mechanism(s) involved in caspase-8 activation, we examined cell surface expression of death receptor (DR)4 and DR5 after triterpenoid treatment. Cell surface DR4 and DR5 expression was significantly up-regulated by CDDO or CDDO-Im but not by CDDO-Me. DR4 and DR5 knockdown with siRNA significantly inhibited apoptosis induced by CDDO and CDDO-Im but had no effect on CDDO-Me-induced killing, suggesting that CDDO and CDDO-Im induce apoptosis by a different mechanism than CDDO-Me. In addition to activating the caspase-8-dependent extrinsic apoptosis pathway, we observed that Bcl-X L overexpression inhibited triterpenoidmediated killing of prostate cancer cell line Du145, suggesting that the intrinsic pathway (via mitochondria) also participates in triterpenoid-mediated killing. In vivo antitumor activity of CDDO-Me was shown using a Du145 tumor xenograft model in nude rats. Altogether, these findings suggest CDDO and related synthetic triterpenoids should be further evaluated as potential novel therapeutics for hormone refractory prostate cancers.
Mitotic catastrophe and apoptosis induced by docetaxel in hormone-refractory prostate cancer cells
Journal of Cellular Physiology, 2008
Studies performed in different experimental and clinical settings have shown that Docetaxel (Doc) is effective in a wide range of tumors and that it exerts its activity through multiple mechanisms of action. However, the sequence of events induced by Doc which leads to cell death is still not fully understood. Moreover, it is not completely clear how Doc induces mitotic catastrophe and whether this process is an end event or followed by apoptosis or necrosis. We investigated the mechanisms by which Doc triggers cell death in hormone-refractory prostate cancer cells by analyzing cell cycle perturbations, apoptosis-related marker expression, and morphologic cell alterations. Doc induced a transient increase in G2/M phase followed by the appearance of G0/1 hypo-and hyperdiploid cells and increased p21 expression. Time-and concentration-dependent apoptosis was induced in up to 70% of cells, in concomitance with Bcl-2 phosphorylation, which was followed by caspase-2 and -3 activation. In conclusion, Doc would seem to trigger apoptosis in hormone-refractory prostate cancer cells via mitotic catastrophe through two forms of mitotic exit, in concomitance with increased p21 expression and caspase-2 activation.
Cancer Research, 2006
Prostate cancer cells are dependent on androgen for growth and survival; as such, inhibition of androgen receptor (AR) activity is the first line of intervention for disseminated disease. Recently, specific cytotoxic agents have been shown to extend survival times in patients with advanced disease. Given the established ability of androgen to modify cell survival in prostate cancer cells, it is imperative to determine the effect of the hormonal environment on cytotoxic response. Here, we show that the response of prostate cancer cells to taxaneinduced cell death is significantly enhanced by androgen stimulation in AR-positive, androgen-dependent prostate cancer cells. Similar results were observed on androgenindependent AR activation. By contrast, AR-positive yet androgen-independent or AR-negative cells were refractory to androgen influence on taxane function. The ability of androgen to potentiate taxane activity was dependent on its mitogenic capacity and was separable from overall AR activity, as coadministration of AR antagonists, G 1 cyclin-dependent kinase inhibitors, or high-dose (growth inhibitory) androgen nullified the proapoptotic function of androgen. Observed induction of cell death was attributed to caspase-dependent apoptosis and correlated with p53 activation. Combined, these data indicate that the cytotoxic effects of taxanes are substantially influenced by the hormonal environment and/or status of AR activity in prostate cancer cells and provide the foundation for refinement and optimization of cytotoxic intervention in prostate cancer. (Cancer Res 2006; 66(24): 11998-2008)
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 2018
Cardiac glycosides (CGs) are natural compounds used to treat congestive heart failure. They have garnered attention as a potential cancer treatment option, especially because they bind to Na/K-ATPase as a target and activate intracellular signaling pathways leading to a variety of cellular responses. In this study we evaluated AMANTADIG, a semisynthetic cardenolide derivative, for its cytotoxic activity in two human androgen-insensitive prostate carcinoma cell lines, and the potential synergistic effects with docetaxel. AMANTADIG induced cytotoxic effects in both cell lines, and a combination with docetaxel showed a moderate and strong synergism in DU145 and PC-3 cells, respectively, at concentrations considerably lower than their IC values. Cell cycle analyses showed that AMANTADIG and its synergistic combination induced G2/M arrest of DU145 and PC-3 cells by modulating Cyclin B1, CDK1, p21 and, mainly, survivin expression, a promising target in cancer therapy. Furthermore, AMANTAD...
Oncology Reports, 2019
Docetaxel (DOC) is one of the most effective chemotherapeutic agents against castration-resistant prostate cancer (CRPC). Despite an impressive initial clinical response, the majority of patients eventually develop resistance to DOC. In tumor metabolism, where tumors preferentially utilize anaerobic metabolism, lactate dehydrogenase (LDH) serves an important role. LDH controls the conversion of pyruvate to lactate, with LDH-A, one of the predominant isoforms of LDH, controlling this metabolic process. In the present study, the role of LDH-A in drug resistance of human prostate cancer (PC) was examined by analyzing 4 PC cell lines, including castration-providing strains PC3, DU145, LNCaP and LN-CSS (which is a hormone refractory cell line established from LNCaP). Sodium oxamate (SO) was used as a specific LDH-A inhibitor. Changes in the expression level of LDH-A were analyzed by western blotting. Cell growth and survival were evaluated with a WST-1 assay. Cell cycle progression and apoptotic inducibility were evaluated by flow cytometry using propidium iodide and Annexin V staining. LDH expression was strongly associated with DOC sensitivity in PC cells. SO inhibited growth of PC cells, which was considered to be caused by the inhibition of LDH-A expression. Synergistic cytotoxicity was observed by combining DOC and SO in LN-CSS cells, but not in LNCaP cells. This combination treatment induced additive cytotoxic effects in PC-3 and DU145 cells, caused cell cycle arrest in G2-M phase and increased the number of cells in the sub-G1 phase of cell cycle in LN-CSS cells. SO promoted DOC induced apoptosis in LN-CSS cells, which was partially caused by the inhibition of DOC-induced increase in LDH-A expression. The results strongly indicated that LDH-A serves an important role in DOC resistance in advanced PC cells and inhibition of LDH-A expression promotes susceptibility to DOC, particularly in CRPC cells. The present study may provide valuable information for developing targeted therapies for CRPC in the future.
Pretreatment of docetaxel enhances TRAIL-mediated apoptosis in prostate cancer cells
Journal of Cellular Biochemistry, 2008
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising cancer therapeutic agent because of its tumor selectivity. TRAIL is known to induce apoptosis in cancer cells but spare most normal cells. In this study, we examined whether treatment of docetaxel (DTX) can enhance apoptotic cell death by TRAIL against androgenindependent prostate cancer (AIPC). The cell death effect of combinations of TRAIL and docetaxel on prostate cancer cell lines (androgen-dependent LNCaP and its derived androgen-independent, metastatic C4-2B) was evaluated by synergisms of apoptosis. Western blot assay and DNA fragmentation assay were used to study the underlying mechanisms of cell death and search for any mechanisms of enhancement of TRAIL induced apoptosis in the presence of docetaxel. In addition, we investigated the in vitro anti-tumor effects of combined docetaxel and TRAIL using MAP kinase inhibitors. Docetaxel itself could not induce apoptotic cell death in 24 h even in high concentration. Apoptotic cell death, however, was drastically enhanced by pretreatment of docetaxel 20 h before TRAIL treatment. Docetaxel enhanced the PARP-1 cleavage and caspases activation by TRAIL especially in androgen-independent, metastatic C4-2B cell line, mainly by phosphorylation of Bcl-2 by JNK activation. It appears that apoptotic cell death was protected by the JNK inhibitor SP600125. The results of our study show that pretreatment of docetaxel is able to enhance the apoptosis produced by TRAIL in prostate cancer cells, especially in hormone-refractory prostate cancer (HRPC).