[Effects of TiO2 nanoparticles on antioxidant function and element content of liver and kidney tissues in young and adult rats].

OBJECTIVE: To compare the effect of TiO2 nanoparticles on antioxidant function and element content of liver and kidney tissues in young and adult rats. METHODS: Forty-eight SD male rats, half in 4-week (youth) old and half in 9-week (adult) old rats, were randomly divided into 8 groups, which were exposed to TiO2 nanoparticles [(75 ± 15) nm, anatase] through intragastric administration at 0, 10, 50 and 200 mg/kg body weight every day for 30 days. The liver and kidney tissues were collected for antioxidant function and element content analysis. RESULTS: 200 mg/kg TiO2 nanoparticles exposure significantly increased the liver total superoxide dismutase (T-SOD) activity and the kidney reduced glutathione (GSH)/oxidized glutathione (GSSG) ratios in young rats, and significantly decreased the liver Mo, Co, Mn and P contents and the kidney Rb and Na contents in young rats. 200 mg/kg TiO2 nanoparticles exposure significantly increased GSH/GSSG ratios and Rb contents and decreased Na contents in the liver of adult rats. No significantly difference was found in antioxidant indexes and elements content in the kidney of adult rats between three experimental groups and control group. CONCLUSION: TiO2 nanoparticles can enhance the antioxidant capacity and decrease the elements content in rat liver and kidney tissues. The liver is the more sensitive target organ and the young animals are more susceptible to TiO2 nanoparticles toxicity by the oral routes.

Mutagenicity and tumorigenicity of the four enantiopure bay-region 3,4-diol-1,2-epoxide isomers of dibenz[a,h]anthracene.

Each enantiomer of the diastereomeric pair of bay-region dibenz[a,h]anthracene 3,4-diol-1,2-epoxides in which the benzylic 4-hydroxyl group and epoxide oxygen are either cis (isomer 1) or trans (isomer 2) were evaluated for mutagenic activity. In strains TA 98 and TA 100 of Salmonella typhimurium, the diol epoxide with (1S,2R,3S,4R) absolute configuration [(-)-diol epoxide-1] had the highest mutagenic activity. In Chinese hamster V-79 cells, the diol epoxide with (1R,2S,3S,4R) absolute configuration [(+)-diol epoxide-2] had the highest mutagenic activity. The (1R,2S,3R,4S) diol epoxide [(+)-diol epoxide-1] also had appreciable activity, whereas the other two bay-region diol epoxide enantiomers had very low activity. In tumor studies, the (1R,2S,3S,4R) enantiomer was the only diol epoxide isomer tested that had strong activity as a tumor initiator on mouse skin and in causing lung and liver tumors when injected into newborn mice. This stereoisomer was about one-third as active as the parent hydrocarbon, dibenz[a,h]anthracene as a tumor initiator on mouse skin; it was several-fold more active than dibenz[a,h]anthracene as a lung and liver carcinogen when injected into newborn mice. (-)-(3R,4R)-3ß,4α-dihydroxy-3,4-dihydro-dibenz[a,h]anthracene [(-)-3,4-dihydrodiol] was slightly more active than dibenz[a,h]anthracene as a tumor initiator on mouse skin, whereas (+)-(3S,4S)-3α,4ß-dihydroxy-3,4-dihydro-dibenz[a,h]anthracene [(+)-3,4-dihydrodiol] had only very weak activity. The present investigation and previous studies with the corresponding four possible enantiopure bay-region diol epoxide enantiomers/diastereomers of benzo[a]pyrene, benz[a]anthracene, chrysene, benzo[c]phenanthrene, dibenz[c,h]acridine, dibenz[a,h]acridine and dibenz[a,h]anthracene indicate that the bay-region diol epoxide enantiomer with [R,S,S,R] absolute stereochemistry has high tumorigenic activity on mouse skin and in newborn mice.

Synthesis and evaluation of curcumin-related compounds containing benzyl piperidone for their effects on human cancer cells.

Eleven curcumin-related compounds containing a benzyl piperidone moiety were synthesized and evaluated for their effects on cultured prostate cancer PC-3 cells, pancreas cancer BxPC-3 cells, colon cancer HT-29 cells and lung cancer H1299 cells. Inhibitory effects of these compounds on the growth of PC-3, BxPC-3, HT-29 and H1299 cells were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. Compounds benzyl piperidone 2 (P2), P4, P7, 4-bromo-2-fluoro-benzyl piperidone 2 (PFBr2), PFBr3 and PFBr4 (see syntheses and structures in Figs. 1, 2) exhibited potent inhibitory effects on the growth of cultured PC-3, BxPC-3, HT-29 and H1299 cells. The IC50 for these compounds was lower than 2 µM in all four cell lines. PFBr4 was 41-, 36-, 40- and 46-fold more active than curcumin for inhibiting the growth of PC-3, BxPC-3, HT-29 and H1299 cells, respectively. The benzyl piperidone-containing compounds studied also stimulated apoptosis in PC-3 cells. Mechanistic studies indicate that the effects of both curcumin and PFBr4 on PC-3 cells were associated with a decrease in phospho-Akt and phospho-extracellular signal-regulated kinase (Erk)1/2. The present study indicates that P2, P4, P7, PFBr2, PFBr3 and PFBr4 may have useful effects on human cancer cells.

Inhibition of progression of androgen-dependent prostate LNCaP tumors to androgen independence in SCID mice by oral caffeine and voluntary exercise.

The effect of oral caffeine or voluntary running wheel exercise (RW) alone or in combination on the progression of human androgen-dependent LNCaP prostate tumors to androgen independence in male severe combined immunodeficiency mice was determined. The mice were injected subcutaneously with LNCaP cells, and when the tumors reached a moderate size, the mice were surgically castrated and treated with caffeine (0.40 mg/ml drinking water) or RW alone or in combination for 42 days. We found that caffeine administration or RW inhibited the progression and growth of androgen-dependent LNCaP tumors to androgen independence, and a combination of the 2 regimens was more effective than the individual regimens alone. The ratios of the percent mitotic cells/caspase-3 positive cells in tumors from the caffeine-treated, RW-treated, or combination-treated mice were decreased by 34%, 38%, and 52%, respectively. Caffeine treatment increased the percentage of mitotic tumor cells undergoing apoptosis (lethal mitosis) whereas RW inhibited the increase in interleukin-6 that occurred during the progression of LNCaP tumors from androgen dependence to androgen independence. Our results indicate that oral administration of caffeine in combination with voluntary exercise may be an effective strategy for the prevention of prostate cancer progression from androgen dependence to androgen independence.

[Effect of titanium dioxide nanoparticles on hemogram in rats with gastric ulcer].

OBJECTIVE: To explore the effect of titanium dioxide (TiO2) nanoparticles on hemogram in rats with gastric ulcer. METHODS: Physicochemical properties of TiO2 nanoparticles were characterized. Twenty-four clear class SD male rats, aging 8 week-old, were randomly divided into 4 groups, 6 rats for each group. 20% acetic acid were injected into the rats' stomach on the border of gastric body and pyloric antrum, and hereby established the gastric ulcer model. The rats in 4 groups were exposed to TiO2 nanoparticles through intragastric administration at 0, 10, 50 and 200 mg/kg body weight respectively for 30 days. Afterwards, the rats were conducted blood routine test and blood coagulation test for analysis. RESULTS: TiO2 nanoparticles were anatase crystals, closely spherical shape, whose average grain diameter was (75 ± 15) nm. The levels of white blood cell (WBC) count ((8.48 ± 3.28)×109/L), lymphocyte (LYM) ((6.85 ± 2.53)×109/L), monocyte (MOD) ((0.27 ± 0.12)×109/L), granulocyte (GRN) ((1.37 ± 0.86)×109/L), red blood cell (RBC) ((8.20 ± 0.49)×109/L) and hematocrit (HCT) ((45.3 ± 1.4)%) in the 200 mg/kg dose group were significantly higher than those in the control group ((2.63 ± 0.34)×109/L, (2.25 ± 0.26)×109/L, (0.05 ± 0.06)×109/L, (0.33 ± 0.26)× 109/L, (4.87 ± 2.37)×109/L and (27.2 ± 13.3)%, respectively; t values were -3.449, -3.825, -3.554, -3.097, -2.972 and -2.936 respectively, P values all < 0.05). The levels of WBC ((6.88 ± 3.06)×109/L), MOD ((0.20 ± 0.07)×109/L), RBC ((7.79 ± 0.48)×109/L) and HCT ((42.7 ± 2.8)%) in 50 mg/kg dose group were also statistically higher than those in the control group (t values were -2.507, -2.367, -2.605 and -2.511 respectively, all P values < 0.05). There was no statistically difference found in other blood routine index and coagulation index between the three experimental groups and control group. CONCLUSION: The long term intake of TiO2 nanoparticles caused a statistically increase in the amount of WBC and RBC in rats with gastric ulcer; however, there was no obvious changes found in blood platelet and coagulation index.

Inhibition of NF-kappaB by (E)3-[(4-methylphenyl)-sulfonyl]-2-propenenitrile (BAY11-7082; BAY) is associated with enhanced 12-O-tetradecanoylphorbol-13-acetate-induced growth suppression and apoptosis in human prostate cancer PC-3 cells.

The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) alone or in combination with an NF-kappaB inhibitor, (E)3-[(4-methylphenyl)-sulfonyl]-2-propenenitrile (BAY 11-7082; BAY), on the growth and apoptosis of human prostate cancer PC-3 cells cultured in vitro or grown in immunodeficient mice were studied. Treatment of cultured PC-3 cells with TPA (0.2-10 ng/ml) for 96 h resulted in growth inhibition and apoptosis in a concentration-dependent manner. BAY inhibited NF-kappaB activity in PC-3 cells as determined by a luciferase reporter assay and enhanced TPA-induced growth inhibition and apoptosis in cultured PC-3 cells. In animal studies, NCr immunodeficient mice were injected subcutaneously with PC-3 cells in Matrigel. Mice with well-established tumors received daily i.p. injections with TPA (100 ng/g body weight/day), BAY (4 microg/g/day), or a combination of TPA (100 ng/g/day) and BAY (4 microg/g/day) for 36 days. Tumor growth occurred in all of the vehicle-treated control mice. The percent of animals with some tumor regression after 36 days of treatment was 0% for the control group, 40% for the TPA group, 50% for the BAY group and 100% for the TPA + BAY group. Mechanistic studies indicated that treatment of the mice with TPA or TPA + BAY decreased proliferation and increased apoptosis in the tumors. Results from our studies indicate that inhibition of NF-kappaB activity is associated with enhanced TPA-induced growth inhibition and apoptosis in PC-3 cells. Inhibition of NF-kappaB activity by suitable pharmacological inhibitors may be an effective strategy for improving the therapeutic efficacy of TPA in prostate cancer.

Inhibitory effect of voluntary running wheel exercise on the growth of human pancreatic Panc-1 and prostate PC-3 xenograft tumors in immunodeficient mice.

In the present study, we investigated the effect of voluntary exercise on the formation and growth of the human pancreas Panc-1 and prostate PC-3 tumors in immunodeficient mice. Female severe combined immunodeficient (SCID) mice were injected subcutaneously with human pancreatic cancer Panc-1 cells, and male SCID mice were injected subcutaneously with human prostate cancer PC-3 cells. Voluntary running wheel exercise for 63 days, starting one week before the subcutaneous injection of Panc-1 or PC-3 tumor cells into SCID mice, suppressed the growth of Panc-1 and PC-3 tumors. The exercise regimen increased the food and fluid consumption in the female and male mice. Exercise also decreased the size of the parametrial fat pads in the female mice and the paradidymis fat pads in the male mice, but there was no effect on the body weight. Mechanistic studies showed that voluntary running wheel exercise inhibited proliferation as reflected by a decreased mitosis, and the exercise regimen also stimulated apoptosis as reflected by the increased caspase-3 (active form) expression in the Panc-1 and PC-3 tumors. Voluntary running wheel exercise decreased the ratio of the percent mitotic cells/apoptotic cells in Panc-1 and PC-3 tumors by 38 and 32%, respectively. The present study demonstrated an inhibitory effect of voluntary exercise on the growth of pancreas and prostate tumors in a SCID mouse xenograft model.

Atorvastatin and celecoxib inhibit prostate PC-3 tumors in immunodeficient mice.

PURPOSE: To investigate the effects and mechanisms of atorvastatin and celecoxib administered individually or in combination on human prostate cancer PC-3 cells cultured in vitro or grown as xenograft tumors in immunodeficient mice. EXPERIMENTAL DESIGN: Human prostate cancer PC-3 cells in culture were treated with atorvastatin and celecoxib alone or in combination. Severe combined immunodeficient (SCID) mice were injected s.c. with PC-3 cells. The mice received daily i.p injections starting 2 days before tumor cell inoculation and continuing during the course of treatment with atorvastatin (10 microg/g body weight/d), celecoxib (10 microg/g/d), a combination of atorvastatin (10 microg/g/d) and celecoxib (10 microg/g/d), or a combination of atorvastatin (5 microg/g/d) and celecoxib (5 microg/g/d). RESULTS: Atorvastatin in combination with celecoxib had stronger effects on growth inhibition and apoptosis of PC-3 cells than either agent used individually. Atorvastatin and celecoxib in combination also had a stronger inhibitory effect on activation of nuclear factor-kappaB and extracellular signal-regulated kinase 1/2 in PC-3 cells than either agent alone. Treatment of SCID mice with combinations of atorvastatin and celecoxib more effectively inhibited the formation and growth of PC-3 tumors in the mice than either agent administered alone. CONCLUSIONS: A combination of atorvastatin and celecoxib had a more potent inhibitory effect on the growth of PC-3 cells cultured in vitro or grown in SCID mice than either agent alone. A combination of atorvastatin and celecoxib may be an effective strategy for the prevention of prostate cancer.

Effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) in combination with paclitaxel (Taxol) on prostate Cancer LNCaP cells cultured in vitro or grown as xenograft tumors in immunodeficient mice.

PURPOSE: To investigate the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) in combination with paclitaxel (Taxol) on prostate cancer cells cultured in vitro or grown as tumors in immunodeficient mice. EXPERIMENTAL DESIGN: Human prostate cancer LNCaP cells in culture were treated with TPA alone or in combination with paclitaxel. NCr immunodeficient mice with well-established LNCaP tumors received i.p. injections with vehicle or with TPA, paclitaxel, or TPA in combination with paclitaxel. The animals either received daily treatment for 5 consecutive days followed by a 2-day intermission, which was repeated for a total of 28 days (experiment 1), or continuous daily treatment for 28 days (experiment 2). RESULTS: Treatment of LNCaP cells with a combination of TPA and paclitaxel synergistically inhibited the growth and induced apoptosis in cultured LNCaP cells, and this treatment also induced a marked increase in phosphorylated c-Jun-NH2-kinase (JNK). In animal experiments, tumor growth occurred in all mice treated with vehicle. When treated with TPA alone, the percentage of animals with some tumor regression was 33% in experiment 1 and 100% in experiment 2. Treatment of animals with paclitaxel alone caused some tumor regression in 17% and 57% of the animals in experiments 1 and 2, respectively. All animals treated with TPA + paclitaxel in both experiments had some tumor regression. CONCLUSIONS: TPA and paclitaxel in combination had a stronger inhibitory effect on the growth of LNCaP cells in culture or as xenograft tumors in immunodeficient mice than either agent alone. Clinical trials with TPA alone or in combination with paclitaxel in patients with prostate cancer may be warranted.

A phase I clinical trial of 12- O-tetradecanoylphorbol-13-acetate for patients with relapsed/refractory malignancies.

Phorbol esters activate protein kinase C and modulate a variety of downstream cell signaling pathways. 12-O-tetradecanoylphorbol-13-acetate (TPA) is a phorbol ester that induces differentiation or apoptosis in a variety of cell lines at low concentrations. A phase I dose escalation trial of TPA was undertaken for patients with relapsed or refractory malignancies. The starting dose was 0.063 mg/m2 and most patients were treated with an intravenous infusion of TPA on days 1-5 and 8-12 followed by a 2-week rest period prior to retreatment. Thirty-five patients were treated. A biological assay was used to monitor levels of TPA-like activity in the blood after treatment. Serious adverse events included individual episodes of gross hematuria, a grand mal seizure, syncope, and hypotension. Many patients had transient fatigue, mild dyspnea, fever, rigors, and muscular aches shortly after the infusion. Dose-limiting toxicities included syncope and hypotension at a dose of 0.188 mg/m2. Only a single patient had evidence of tumor response. These studies establish 0.125 mg/m2 as the maximally tolerated dose when TPA is administered on this schedule.

Inhibitory effect of 12-O-tetradecanoylphorbol-13-acetate alone or in combination with all-trans-retinoic acid on the growth of LNCaP prostate tumors in immunodeficient mice.

Clinically achievable concentrations of 12-O-tetradecanoylphorbol-13-acetate (TPA; 0.16-0.32 nM) and all-trans-retinoic acid (ATRA; 0.5-1 micro M) had a synergistic inhibitory effect on the growth of cultured LNCaP prostate cancer cells, and apoptosis was markedly stimulated. In additional studies, NCr immunodeficient mice received s.c. injection with LNCaP cells in Matrigel. After 4-6 weeks, mice with well-established tumors received i.p. injection with vehicle, TPA (0.16 nmol/g body weight), ATRA (0.5 nmol/g body weight), or TPA+ATRA in vehicle once a day for 46 days. Tumor growth occurred in all of the vehicle-treated control mice. The percentage of animals with some tumor regression after 21 days of treatment was 0% for the control group, 31% for the ATRA group, 62% for the TPA group, and 100% for the TPA+ATRA group (13 mice/group). Although treatment of the mice with TPA or TPA+ATRA continued to inhibit tumor growth for the duration of the 46-day study, treatment of the mice with ATRA alone did not inhibit tumor growth beyond 28 days of daily injections (6 mice/group). Mechanistic studies indicated that treatment of the mice with TPA or TPA+ATRA for 46 days increased apoptosis in the tumors, and treatment with TPA+ATRA also decreased the mitotic index. Because the dose of TPA used in this study was effective and resulted in clinically achievable blood levels, clinical trials with TPA alone or in combination with ATRA in patients with prostate cancer may be warranted.

Administration of a phorbol ester to patients with hematological malignancies: preliminary results from a phase I clinical trial of 12-O-tetradecanoylphorbol-13-acetate.

PURPOSE: Phorbol esters are capable of inducing a broad range of cellular effects,including the maturation/differentiation of hematopoietic cell lines (E. Huberman and M. F. Callaham, Proc. Natl. Acad. Sci. USA, 76: 1293-1297, 1979; J. Lotem and L. Sachs, Proc. Natl. Acad. Sci. USA, 76: 5158-5162, 1979; G. Rovera et al., Proc. Natl. Acad. Sci. USA, 76: 2779-2783, 1979; H. P. Koeffler, J. Clin. Investig., 66: 1101-1108, 1980). The ability to induce this differentiation at very low concentrations stimulated investigators to administer a phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), to patients with myeloid leukemias in the People's Republic of China (Z. T. Han et al., Proc. Natl. Acad. Sci. USA, 95: 5357-5361, 1998). The tolerability of this therapy in China prompted Phase I studies of TPA in the United States. The purpose of this report is to demonstrate the tolerance of TPA at doses that result in detectable biological activity in blood and malignant cells. EXPERIMENTAL DESIGN: TPA was administered to patients with relapsed/refractory hematological malignancies. RESULTS: Phenotypic effects were detected in malignant cells and TPA-associated biological activity was present in blood for up to several hours after the infusion. CONCLUSIONS: These studies confirm the feasibility of TPA administration to humans and establish the foundation for the development of phorbol esters as therapy for patients with a variety of malignant and nonmalignant disorders.

A sensitive bioassay for measuring blood levels of 12-O-tetradecanoylphorbol-13-acetate (TPA) in patients: preliminary pharmacokinetic studies.

12-O-Tetradecanoylphorbol-13-acetate (TPA) is a potent stimulator of differentiation in myelocytic leukemia cells, and it has been shown to have activity in patients with acute myelocytic leukemia. Because attempts to develop a suitable mass spectrometry assay for TPA were unsuccessful (because of the lack of sufficient sensitivity), we developed a novel and highly sensitive blood level bioassay for TPA that measures ethyl acetate-extractable differentiating activity in blood. Differentiating activity in ethyl acetate extracts of blood was measured in HL-60 cells by measuring the formation of adherent cells. The sensitivity of the assay was approximately 0.1 ng TPA/ml blood. The assay for TPA has a high degree of specificity and does not measure deesterifed potential metabolites (phorbol, phorbol-13-acetate, or phorbol-12-myristate), and the presence of GM-CSF, G-CSF, interferon-alpha, or interferon-gamma does not interfere with the assay. Blood levels of TPA as measured by the bioassay immediately after an IV infusion of TPA (0.125 mg/m2; approximately 0.25 mg per patient) and 1 and 3 h later were 1.75 +/- 0.55, 0.93 +/- 0.54, and 0.69 +/- 0.42 ng/ml, respectively (mean +/- SD from eight infusions in five patients). Terminal half-lives were determined in a few patients where TPA blood levels were measured at multiple time intervals after the TPA infusion. In these patients, the terminal half-life was 11.1 +/- 3.9 h (from five infusions in four patients). To the best of our knowledge, this is the first analytical method for the measurement of TPA.

Curcumin analogues with high activity for inhibiting human prostate cancer cell growth and androgen receptor activation.

The androgen receptor (AR) has a critical role in prostate cancer development and progression. Several curcumin analogues (A10, B10, C10, E10 and F10) with different linker groups were investigated for their effects in human prostate cancer CWR­22Rv1 and LNCaP cell lines. The ability of these compounds to inhibit testosterone (TT)­ or dihydrotestosterone (DHT)­induced AR activity was determined by an AR­linked luciferase assay and by TT­ or DHT­induced expression of prostate specific antigen. Compounds F10 and E10 had stronger inhibitory effects on the growth of cultured CWR­22Rv1 and LNCaP cell lines, and they also had enhanced stimulatory effects on apoptosis compared with curcumin and other curcumin analogues (A10, B10, C10) in CWR­22Rv1 cells. E10 and F10 were more potent inhibitors of AR activity than curcumin, A10 and B10. The higher activities of E10 and F10 may be correlated with a heteroatom linker. The results indicate that one of the potential mechanisms for the anticancer effect of the curcumin analogues was inhibition of AR pathways in human prostate cancer cells.

Inhibition of IL-6 expression in LNCaP prostate cancer cells by a combination of atorvastatin and celecoxib.

In the present study, we investigated the effect of a combination of atorvastatin and celecoxib on the formation of interleukin (IL)-6, a cytokine that is increased during the progression of LNCaP tumors from androgen dependence to androgen independence. Culturing LNCaP cells in androgen­depleted (AD) medium increased the levels of IL-6 and survivin, and treatment of the cells in AD medium with a combination of atorvastatin and celecoxib strongly inhibited the increase in IL-6 and survivin which is one of the downstream targets of the IL-6 signaling pathway. Addition of recombinant IL-6 partially abrogated the combined effect of atorvastatin and celecoxib on apoptosis in LNCaP cells cultured in AD medium. In SCID mice, we found that the levels of IL-6 and survivin expression were increased when LNCaP tumors became androgen-independent. Treatment of the mice with atorvastatin or celecoxib alone caused decrease in the levels of IL-6 and survivin as LNCaP tumors became androgen-independent, but treatment of the mice with a combination of celecoxib and atorvastatin resulted in a much stronger inhibition in the increase in IL-6 and survivin expression. Our results indicate that decreases in IL-6 and survivin levels by atorvastatin and celecoxib administration are associated with increased apoptosis in LNCaP cells treated with this drug combination. Our in vivo studies indicate that the inhibitory effect of a combination of atorvastatin and celecoxib on the progression of androgen-dependent LNCaP xenograft tumors to androgen independence is associated with inhibition of the increase in IL-6 and survivin that occurs when androgen-dependent LNCaP prostate tumors become androgen-independent.

Combination of Lipitor and Celebrex inhibits prostate cancer VCaP cells in vitro and in vivo.

BACKGROUND/AIM: Lipitor is a cholesterol-lowering drug and Celebrex is a Cyclooxygenase-2 inhibitor. We investigated the effects of Lipitor and Celebrex on human prostate cancer VCaP cells cultured in vitro and grown as orthotopic xenograft tumors in SCID mice. MATERIALS AND METHODS: Apoptosis was measured by morphological assessment and caspase-3 assay. Nuclear factor-kappa B (NF-κB) activation was determined by luciferase reporter assay. B-cell lymphoma-2 (Bcl2) was measured by western blotting and immunohistochemistry. Orthotopic prostate tumors were monitored by the IVIS imaging system. RESULTS: the combination of Lipitor and Celebrex had stronger effects on the growth and apoptosis of VCaP cells than did either drug alone. The combination more potently inhibited activation of NFκB and expression of Bcl2 than either drug alone. The growth of orthotopic VCaP prostate tumors was strongly inhibited by treatment with the drug combination. CONCLUSION: Administration of Lipitor and Celebrex in combination may be an effective strategy for inhibiting the growth of prostate cancer.

A triple combination of atorvastatin, celecoxib and tipifarnib strongly inhibits pancreatic cancer cells and xenograft pancreatic tumors.

Because K-Ras mutation and cyclooxygenase-2 (COX-2) overexpression are hallmarks of majority of pancreatic cancer patients, an approach to inhibit the progression and growth of pancreatic cancer using the simultaneous administration of agents that inhibit the function of both targets, should be considered. In the present study, we assessed the effects of atorvastatin (Lipitor), celecoxib (Celebrex) and tipifarnib (Zarnestra) on the growth of human pancreatic cancer. In the in vitro studies, we found that treatment of human pancreatic tumor cells with a combination of atorvastatin, celecoxib and tipifarnib had a stronger inhibitory effect on growth and a stronger stimulatory effect on apoptosis than each drug alone or for any combination of two drugs. We also found that treatment of Panc-1 cells with a combination of all three drugs strongly decreased the levels of phosphorylated Erk1/2 and Akt. In an animal model of xenograft tumors in severe combined immunodeficient (SCID) mice, we found that daily i.p. injections of a combination of atorvastatin, celecoxib and tipifarnib had a stronger inhibitory effect on the growth of the tumors in mice than each drug alone or for any combination of two drugs. The results of our study indicate that a combination of atorvastatin, celecoxib and tipifarnib may be an effective strategy for the treatment of pancreatic cancer.

Anticancer activity of Acanthopanax trifoliatus (L) Merr extracts is associated with inhibition of NF-kB activity and decreased Erk1/2 and Akt phosphorylation.

Acanthopanax trifoliatus (L) Merr (AT) is commonly used as an herbal medicine and edible plant in some areas of China and other Asian countries. AT is thought to have anticancer effects, but potential mechanisms remain unknown. To assess the anticancer properties of AT, we exposed prostate cancer cells to AT extracts and assessed cell proliferation and signaling pathways. An ethanol extract of AT was suspended in water followed by sequential extraction with petroleum ether, ethyl acetate and n-butanol. PC-3 cells were treated with different concentrations of each extract and cell viability was determined by the MTT and trypan blue exclusion assays. The ethyl acetate extract of the ethanol extract had a stronger inhibitory effect on growth and a stronger stimulatory effect on apoptosis than any of the other extracts. Mechanistic studies demonstrated that the ethyl acetate extract suppressed the transcriptional activity of NF-kB, increased the level of caspase-3, and decreased the levels of phospho-Erk1/2 and phospho-Akt. This is the first report on the anticancer activity of AT in cultured human prostate cancer cells. The results suggest that AT can provide a plant-based medicine for the treatment or prevention of prostate cancer.

Potent inhibitory effect of δ-tocopherol on prostate cancer cells cultured in vitro and grown as xenograft tumors in vivo.

In the present study, the effects of δ-tocopherol (δ-T) on growth and apoptosis of human prostate cancer cells were determined and compared with that of α-tocopherol (α-T), a commonly used form of vitamin E. Treatment of human prostate cancer cells with δ-T resulted in strong growth inhibition and apoptosis stimulation, while the effects of α-T were modest. The strong effects of δ-T on the cells were associated with suppression of androgen receptor (AR) activity and decreased level of prostate specific antigen (PSA) that is a downstream target of the AR signaling. In the in vivo study, we found that δ-T had a more potent inhibitory effect on the formation and growth of prostate xenograft tumors than that of α-T. Moreover, δ-T inhibited proliferation and stimulated apoptosis in the tumors. The present study identified δ-T as a better form of vitamin E than α-T for future clinical studies of prostate cancer prevention.

Effects of pyridine analogs of curcumin on growth, apoptosis and NF-κB activity in prostate cancer PC-3 cells.

Twelve pyridine analogs of curcumin were studied for their effects on growth and apoptosis in human prostate cancer PC-3 cells. The ability of these compounds to inhibit the transcriptional activity of nuclear factor-kappa B (NF-κB) and the level of phosphorylated extracellular signal-regulated kinases (phospho-ERK1/2) in PC-3 cells was also determined. Treatment of PC-3 cells with the pyridine analogs of curcumin resulted in concentration-dependent growth inhibition and apoptosis stimulation. Only pyridine analogs of curcumin with a tetrahydrothiopyrane-4-one linker (FN compounds) exhibited a strong inhibitory effect on growth and a strong stimulatory effect on apoptosis at low concentrations (≤ 1 µM). Mechanistic studies showed that NF-κB transcriptional activity in PC-3 cells was strongly inhibited by treatment with group FN compounds. Treatment of PC-3 cells with 1 µM FN1 resulted in a decrease of activated ERK1/2. Results from the present study indicate that FN compounds warrant further in vivo studies using suitable animal models of prostate cancer.