LQB-118 Suppresses Migration and Invasion of Prostate Cancer Cells by Modulating the Akt/GSK3ß Pathway and MMP-9/Reck Gene Expression.

BACKGROUND/AIM: Prostate cancer (PCa) is one of the most common malignancies in adult men. LQB-118 is a pterocarpanquinone with antitumor activity toward prostate cancer cells. It inhibits cell proliferation by down-regulating cyclins D1 and B1 and up-regulating p21. However, the effects of LQB-118 on PCa cell migration are still unclear. Herein, the LQB-118 effects on PCa metastatic cell migration/invasion and its mechanism of action were evaluated. MATERIALS AND METHODS: PC3 cells were treated with LQB-118 or Paclitaxel (PTX), and cell migration (wound healing and Boyden chamber assays) and invasion (matrigel assay) were determined. The LQB-118 mechanisms were evaluated by αVßIII protein expression (flow cytometry), protein phosphorylation (Western blot), and mRNA expression (qPCR). RESULTS: LQB-118 impaired PCa cell migration and invasion, down-regulated Akt phosphorylation, and also reduced GSK3ß phosphorylation, through a FAK-independent pathway. Also, it was observed that LQB-118 controlled the invasiveness behavior by reducing matrix metalloproteinase-9 (MMP-9) and up-regulating reversion-inducing cysteine rich protein with Kazal motifs (Reck) mRNA levels. Interestingly, LQB-118 increased integrin αvßIII expression, but this effect was not related to its activation, since the cell adhesion ability was reduced after LQB-118 treatment. CONCLUSION: These data highlight novel LQB-118 mechanisms in prostate cancer cells. LQB-118 acts as a negative regulator of the Akt/GSK3 signaling pathway and can modulate PCa cell proliferation, death, and migration/invasion. The results also support the use of LQB-118 for the treatment of metastatic PCa, alone or combined with another chemotherapeutic agent, due to its demonstrated pleiotropic activities.

Synthesis and Biological Evaluation of Cyclic Analogues from Nitrone LQB-278: A New Potential Antileukemia Compound.

BACKGROUND/AIM: A new set of LQB-nitrones and analogues was synthesized to evaluate anticancer activity based on the substitution of the terpenyl moiety of the antileukemic compound LQB-278 by the conformationally restricted cinnamyl ether. MATERIALS AND METHODS: A structure-activity relationship study was performed in vitro on Jurkat cells to screen the antileukemic activity of LQB-nitrones and analogues and elucidate the mechanisms of action of the most active derivatives. RESULTS: The cynamyl ramification and its ortho position aldehyde substitution improved the antileukemic activity. Three compounds showed an in vitro antiproliferative action, but only 5b induced apoptosis. Analysis of the molecular mechanisms showed increased expression of the cell cycle inhibitor p21CIP1/WAF1/Sdi1, caspase 3, Fas receptor, and Bax/Bcl-2 ratio. CONCLUSION: The cinnamyl derivative 5b (LQB-461) presented higher antileukemic effects than the prototype terpenyl nitrone, inducing Jurkat cell death by activating both extrinsic and intrinsic pathways of apoptosis. Therefore, this compound is a new promising candidate drug against leukemia.

Anti-arthritic properties of crude extract from Chenopodium ambrosioides L. leaves.

OBJECTIVES: To evaluate the effect of hydroalcoholic crude extract (HCE) from Chenopodium ambrosioides leaves on the development of type II collagen-induced arthritis (CIA) and on pro-inflammatory cytokine balance. METHODS: Collagen-induced arthritis was induced in DBA1/J mice. On the 21st day, the mice were treated orally with HCE or methotrexate, daily. Six weeks after beginning the treatment, the following measures were determined: lymphoid organs cell numbers, percentage of blood cells, IL-6, IFN-γ, TNF-α and IL-17 serum concentrations, activity of hepatic and kidney glutathione S-transferase, hepatic 7-ethoxyresorufin-O-deethylase activity, bone density and histopathology. KEY FINDINGS: Treatment of CIA mice with HCE 5 mg/kg (HCE5) reduced the percentage of neutrophils and macrophages and the number of bone marrow cells and increased the lymphocyte numbers and the inguinal lymph node cellularity. This treatment inhibited the serum concentration of IL-6 and TNF-α, which may be related to the preservation of bone density and to the slight thickening of periarticular tissues, with minimal fibrosis and fibroblast proliferation in the joints. The CIA group presented advanced articular erosion and synovial hyperplasia. Phytochemical analysis showed mainly flavonols. CONCLUSIONS: HCE5 presented anti-arthritic potential and reduced IL-6 and TNF-α, which participate directly in the development and maintenance of the inflammatory process in rheumatoid arthritis.

The orally active pterocarpanquinone LQB-118 exhibits cytotoxicity in prostate cancer cell and tumor models through cellular redox stress.

BACKGROUND: The targeted induction of reactive oxygen species (ROS) is a developing mechanism for cancer therapy. LQB-118 is a pterocarpanquinone and ROS-inducing agent with proven antineoplastic activity. Here, LQB-118 efficacy and mechanism of activity, were examined in Prostate Cancer (PCa) cell and tumor models. METHODS: PC3, LNCaP, and LAPC4 PCa cells were applied. Dicoumarol treatment was used to inhibit quinone reductase activity. N-acetylcysteine (NAC) was applied as a ROS scavenger. ROS production was quantified by H2 DCFDA flow cytometry. LQB-118 treated cells were evaluated for changes in lipid peroxidation, viability, and apoptosis. Treatment-induced gene expression was measured by RT-qPCR and Western Blot. SOD1 knockdown was achieved with siRNA or miRNA mimic transfection. MicroRNA specificity was determined by 3'UTR reporter assay. Oral LQB-118 treatment (10 mg/kg/day) efficacy was determined in athymic male nude mice bearing subcutaneous PC3 xenograft tumors. RESULTS: LQB-118 treatment triggered PCa cell death and apoptosis. Therapeutic activity was at least partially dependent upon quinone reduction and ROS generation. LQB-118 treatment caused an increase in cellular ROS and lipid peroxidation. Treated cells exhibited elevated levels of NQO1, Nrf2, and SOD1. The miRNAs miR-206, miR-1, and miR-101 targeted and reduced SOD1 expression. The knockdown of SOD1, by siRNA or miRNA, enhanced LQB-118 cytotoxicity. Orally administered LQB-118 treatment significantly reduced the growth of established PCa xenograft tumors. CONCLUSION: LQB-118 is a developing and orally active pterocarpanquinone agent that effectively kills PCa cells through quinone reduction and ROS generation. The inhibition SOD1 expression enhances LQB-118 activity, presumably by impairing the cellular antioxidant response.

Synthesis of N-methylarylnitrones derived from alkyloxybenzaldehydes and antineoplastic effect on human cancer cell lines.

New O-isoprenylated-N-methylarylnitrones derived from isomeric o, m and p-hydroxybenzaldehydes have been prepared and the antineoplastic effects on human cancer cell lines were evaluated. The O-geranylated nitrone LQB-278 (1b) and its isomers 2b and 3b inhibited the NO production, but the anti-leukemic activity was drastically dependent on nitrone isomer, with the 1b being the most effective one (IC50 of 6.7 µM) on Jurkat leukemia cell, by MTT assay. In addition, 1b up-regulated p21CIP1/WAF1/Sdi1 protein expression (flow cytometry), a cell cycle inhibitor, reduced cell growth, and induced DNA fragmentation (increased sub-G1 phase cells) and phosphatidylserine externalization in plasmatic membrane (increased annexin V positive cells). Finally, the 1b up-regulation of p21 expression and apoptosis induction seem to be the mechanisms by which it promotes its anti-leukemic effects, making this new molecular architecture a promising prototype for leukemia intervention.

Antitumor screening of Pterodon pubescens terpenic fraction indicates high sensitivity for lymphocytic leukemia cells.

Cancer is the second leading cause of human mortality worldwide. Therefore, the search for new drugs or alternative therapy strategies has been required. Anticancer agents have been developed from plants since the 1950s and natural products still represent an important source of new and promising bioactive molecules. This work describes the cytotoxic effects of SF5 on tumor cells of high prevalence in the world and investigated some mechanisms of its antitumor action. The antitumor screening was performed with human lung carcinoma (A549), human breast (MCF-7) and prostate (PC-3) adenocarcinoma and chronic myeloid and acute lymphocytic leukemia cell lines. The acute lymphocytic leukemia Jurkat cells presented high sensitivity to the cytotoxic effects of SF5 (inhibition of 85-90%), compared with either the chronic myeloid leukemia K562 or solid tumor cell lines (lung, breast and prostate). SF5 arrested the cell cycle in G1 phase, which may be related with the observed downregulation of mRNA expression of c-Myc transcription factor at 24 h and 36 h. SF5 treatment induced cytochrome c release from mitochondria to cytosol, leading the Jurkat cells into apoptosis, which was evidenced by the internucleosomal fragmented DNA and increased number of annexin V-FITC positive cells. The SF5 showed high cytotoxicity for lymphocytic leukemia cells and low or none for solid tumor cells, without toxicity for peripheral mononuclear cells of healthy humans. SF5 altered gene expression, arrested the cell cycle and induced apoptosis via the mitochondrial pathway, similar to traditional antineoplastic chemotherapeutic drugs.

The pterocarpanquinone LQB-118 inhibits tumor cell proliferation by downregulation of c-Myc and cyclins D1 and B1 mRNA and upregulation of p21 cell cycle inhibitor expression.

The incidence of cancer grows annually worldwide and in Brazil it is the second cause of death. The search for anti-cancer drugs has then become urgent. It depends on the studies of natural and chemical synthesis products. The antitumor action of LQB-118, a pterocarpanquinone structurally related to lapachol, has been demonstrated to induce mechanisms linked to leukemia cell apoptosis. This work investigated some mechanisms of the in vitro antitumor action of LQB-118 on prostate cancer cells. LQB-118 reduced the expression of the c-Myc transcription factor, downregulated the cyclin D1 and cyclin B1 mRNA levels and upregulated the p21 cell cycle inhibitor. These effects resulted in cell cycle arrest in the S and G2/M phases and inhibition of tumor cell proliferation. LQB-118 also induced programmed cell death of the prostate cancer cells, as evidenced by internucleosomal DNA fragmentation and annexin-V positive cells. Except the cell cycle arrest in the S phase and enhanced c-Myc expression, all the mechanisms observed here for the in vitro antitumor action of LQB-118 were also found for Paclitaxel, a traditional antineoplastic drug. These findings suggest new molecular mechanisms for the LQB-118 in vitro antitumor action.

Pterodon polygalaeflorus essential oil modulates acute inflammation and B and T lymphocyte activation.

The increased life expectancy of the population has led to increasing incidences of cancer, chronic inflammatory and autoimmune diseases. Thus the continuous search for new drugs is necessary because ineffectiveness and adverse effects have been described for standard drugs. Essential oils are important sources of bioactive metabolites and several clinical trials have been developed using them. The Pterodon genus has been used in traditional medicine to treat rheumatic disorders, thus this work investigated the properties of essential oil from Pterodon polygalaeflorus fruits (EsOPpg) on acute inflammation and lymphocyte activation. The essential oil was obtained by hydrodistillation and its components were identified by GC/MS. The anti-inflammatory response was assessed using the air pouch model. Antinociceptive potential was evaluated using the writhing model. Lymphocyte phenotyping, cell cycle and apoptosis were analyzed by flow cytometry. EsOPpg promoted a reduction in leukocyte counts and protein concentration in the exudate, and reduced vasodilatation and inflammatory cell infiltrate in air pouch tissue. No antinociceptive effect was demonstrated for the doses tested. EsOPpg inhibited lymphocyte proliferation, arresting the cell cycle in G1 phase, and induced apoptosis in these cells. EsOPpg downregulated both the total number of CD8(+) T cells and the activated subpopulation (CD8(+)CD69(+)), while promoting upregulation of the total number of CD19(+) and CD19(+)CD69(+) B cells. In conclusion, Pterodon polygalaeflorus essential oil diminished the acute inflammatory response and inhibited lymphocyte proliferation, reducing neutrophil recruitment into the cavity and air pouch tissue and promoting distinct modulations of the activation level of each lymphocyte subpopulation.

Terpenic fraction of Pterodon pubescens inhibits nuclear factor kappa B and extracellular signal-regulated protein kinase 1/2 activation and deregulates gene expression in leukemia cells.

BACKGROUND: Plant derived compounds have been shown to be important sources of several anti-cancer agents. As cell cycle deregulation and tumor growth are intimately linked, the discovery of new substances targeting events in this biochemical pathway would be of great value. The anti-leukemic effect of an ethanolic extract of Pterodon pubescens seeds (EEPp) has been previously demonstrated and now we show that a terpenic subfraction (SF5) of EEPp containing farnesol, geranylgeraniol and vouacapan derivatives induces apoptosis in the human chronic myelogenous leukemia cell line K562. This work addresses SF5's antiproliferative mechanisms in these cells since they are still unclear. METHODS: DNA synthesis in K562 cells was assessed by [3H]-methyl-thymidine incorporation and cell cycle status by flow cytometry. The expression of cyclins D1 and E2, of the cell cycle inhibitor p21 and of the proto-oncogene c-myc was evaluated by semi-quantitative RT-PCR. Extracellular-signal-regulated kinases (ERK) 1/2 and nuclear factor kappa B (NF-κB) activation was evaluated by western blotting. RESULTS: In K562 cells, SF5 treatment induced a higher inhibition of DNA synthesis and cell growth than the original EEPp hexanic fraction from which SF5 originated, and also arrested the cell cycle in G1. Exposure of these cells to SF5 led to a decrease in cyclin E2 and c-myc expression while p21 mRNA levels were increased. Furthermore, SF5 inhibited the activation of mitogen-activated protein kinase (MAPK) ERK 1/2 and NF-κB. CONCLUSIONS: This work suggests that the anti-leukemic action of SF5 is linked to the inhibition of ERKs, NF-κB and c-myc signaling pathways resulting in reduced cyclin E2 mRNA expression and cell cycle arrest in the G1 phase.

Terpenic subfraction of Pterodon pubescens induces apoptosis of K562 leukemic cells by modulating gene expression.

Deregulation of cell proliferation and apoptosis is linked to malignant cell development. Leukemia is the most frequent cancer in children, and plants are important sources for new potential anti-cancer agents. Although anti-tumoral effects have been shown for Pterodon pubescens extracts, the mechanisms are still obscure. This study describes in Pterodon pubescens a furane diterpene only reported in Pterodon polygalaeflorus, the methyl-6α-acetoxy-7ß-hydroxyvouacapan-17ß-oate, indicated by HRMS and 13C-NMR analysis, and demonstrates some mechanisms of the anti-leukemia action of its terpene subfraction SF5. SF5 induced cytotoxic and anti-proliferative effects on K562 cells. Increased sub-G1 nuclei and Annexin V+-FITC cells confirmed apoptosis of leukemic cells by treatment of these cells with SF5. Down-regulation of DNMT1 gene transcription and over-expression of Apaf-1 mRNA suggested that SF5 may be inducing apoptosis of K562 cells by epigenetic up-regulation of pro-apoptotic proteins involved in the mitochondrial intrinsic pathway.