Carla Randolph

Liposome encapsulation of curcumin and resveratrol in combination reduces prostate cancer incidence in PTEN knockout mice.

Increasing interest in the use of phytochemicals to reduce prostate cancer led us to investigate 2 potential agents, curcumin and resveratrol as preventive agents. However, there is concern about the bioavailability of these agents pertinent to the poor absorption and thereby limiting its clinical use. With the view to improve their bioavailability, we used the liposome encapsulated curcumin, and resveratrol individually and in combination in male B6C3F1/J mice. Further, we examined the chemopreventive effect of liposome encapsulated curcumin and resveratrol in combination in prostate‐specific PTEN knockout mice. In vitro assays using PTEN‐CaP8 cancer cells were performed to investigate the combined effects curcumin with resveratrol on (i) cell growth, apoptosis and cell cycle (ii) impact on activated p‐Akt, cyclin D1, m‐TOR and androgen receptor (AR) proteins involved in tumor progression. HPLC analysis of serum and prostate tissues showed a significant increase in curcumin level when liposome encapsulated curcumin coadministered with liposomal resveratrol (p < 0.001). Combination of liposomal forms of curcumin and resveratrol significantly decreased prostatic adenocarcinoma in vivo (p < 0.001). In vitro studies revealed that curcumin plus resveratrol effectively inhibit cell growth and induced apoptosis. Molecular targets activated due to the loss of phosphatase and tensin homolog (PTEN) including p‐Akt, cyclin D1, mammalian target of rapamycin and AR were downregulated by these agents in combination. Findings from this study for the first time provide evidence on phytochemicals in combination to enhance chemopreventive efficacy in prostate cancer. These findings clearly suggest that phytochemicals in combination may reduce prostate cancer incidence due to the loss of the tumor suppressor gene PTEN.

Effect of Soy Protein Isolate Supplementation on Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy: A Randomized Trial

IMPORTANCE Soy consumption has been suggested to reduce risk or recurrence of prostate cancer, but this has not been tested in a randomized trial with prostate cancer as the end point. OBJECTIVE To determine whether daily consumption of a soy protein isolate supplement for 2 years reduces the rate of biochemical recurrence of prostate cancer after radical prostatectomy or delays such recurrence. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind trial conducted from July 1997 to May 2010 at 7 US centers comparing daily consumption of a soy protein supplement vs placebo in 177 men at high risk of recurrence after radical prostatectomy for prostate cancer. Supplement intervention was started within 4 months after surgery and continued for up to 2 years, with prostate-specific antigen (PSA) measurements made at 2-month intervals in the first year and every 3 months thereafter. INTERVENTION Participants were randomized to receive a daily serving of a beverage powder containing 20 g of protein in the form of either soy protein isolate (n=87) or, as placebo, calcium caseinate (n=90). MAIN OUTCOMES AND MEASURES Biochemical recurrence rate of prostate cancer (defined as development of a PSA level of ≥0.07 ng/mL) over the first 2 years following randomization and time to recurrence. RESULTS The trial was stopped early for lack of treatment effects at a planned interim analysis with 81 evaluable participants in the intervention group and 78 in the placebo group. Overall, 28.3% of participants developed biochemical recurrence within 2 years of entering the trial (close to the a priori predicted recurrence rate of 30%). Among these, 22 (27.2%) occurred in the intervention group and 23 (29.5%) in the placebo group. The resulting hazard ratio for active treatment was 0.96 (95% CI, 0.53-1.72; log-rank P = .89). Adherence was greater than 90% and there were no apparent adverse events related to supplementation. CONCLUSION AND RELEVANCE Daily consumption of a beverage powder supplement containing soy protein isolate for 2 years following radical prostatectomy did not reduce biochemical recurrence of prostate cancer in men at high risk of PSA failure. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00765479.

Exisulind in Combination with Celecoxib Modulates Epidermal Growth Factor Receptor, Cyclooxygenase-2, and Cyclin D1 against Prostate Carcinogenesis: In vivo Evidence

Purpose: Nonsteroidal anti-inflammatory drugs mediate anticancer effects by modulating cyclooxygenase-2 (COX-2)-dependent and/or COX-2–independent mechanism(s); however, the toxicity issue is a concern with single agents at higher doses. In this study, we determined the combined effect of celecoxib, a COX-2 inhibitor, along with exisulind (sulindac sulfone/Aptosyn) at low doses in prostate cancer. Experimental Design: We used a sequential regimen of N-methyl-N-nitrosourea + testosterone to induce prostate cancer in Wistar-Unilever rats. Following carcinogen treatment, celecoxib and exisulind individually and their combination at low doses were given in NIH-07 diet for 52 weeks. We determined the incidence of prostatic intraepithelial neoplasia, adenocarcinomas, rate of tumor cell proliferation, and apoptosis. Immunohistochemical and Western blot analysis were done to determine COX-2, epidermal growth factor receptor (EGFR), Akt, androgen receptor, and cyclin D1 expression. Serum prostaglandin E2 and tumor necrosis factor-α levels were determined using enzyme immunoassay/ELISA assays. Results: The rats that received celecoxib in combination with exisulind at low doses showed a significant decrease in prostatic intraepithelial neoplasia and adenocarcinomas as well as an enhanced rate of apoptosis. An overall decrease in COX-2, EGFR, Akt, androgen receptor, and cyclin D1 expression was found associated with tumor growth inhibition. Reduced serum levels of COX-2 protein, prostaglandin E2, and tumor necrosis factor-α indicated anti-inflammatory effects. A strong inhibition of total and phosphorylated form of EGFR (Tyr992 and Tyr845) and Akt (Ser473) was significant in rats given with these agents in combination. Conclusions: In this study, we show for the first time that the combination of celecoxib with exisulind at low doses could prevent prostate carcinogenesis by altering key molecular events.

Differential Effects of Selenium on Benign and Malignant Prostate Epithelial Cells : Stimulation of LNCaP Cell Growth by Noncytotoxic, Low Selenite Concentrations

We examined the hypothesis that nontoxic concentrations of selenium induce apoptosis and growth inhibition selectively in prostate cancer cells but not in benign prostate cells. Nontumorigenic BPH-1 prostate epithelial cells, androgen-sensitive LNCaP, and androgen-independent PC-3 prostate cancer cells were exposed to sodium selenite at 1 to 10 μ mol/l for 24 to 72 h. Cell proliferation, viability, and apoptosis were assessed by MTT assay, trypan blue exclusion, flow cytometry, DNA laddering, and caspase activation. BPH-1 cells were more sensitive for cytotoxic selenium effects than malignant prostate cells, whereas LNCaP cells were more sensitive than PC-3 cells. At noncytotoxic selenium concentrations, there was no apoptosis in BPH-1 and PC-3 cells and no growth inhibition of LNCaP and BPH-1 cells. PC-3 cells were refractory to apoptosis induction but were growth inhibited at noncytotoxic concentrations. LNCaP cells were growth stimulated at 1 μ mol/l and sensitive to apoptosis induction at higher noncytotoxic concentrations. Thus, noncytotoxic selenite concentrations did not induce growth inhibition or apoptosis selectively in prostate cancer cells. Growth stimulation of LNCaP cells by low concentrations suggests the possibility of adverse effects of selenium supplementation on hormone sensitive prostate cancer, whereas inhibition of PC-3 cell proliferation at noncytotoxic concentrations suggests potential benefit of selenium in advanced prostate cancer.

Abnormal Relaxin Secretion during Pregnancy in Women with Type 1 Diabetes

To test the hypothesis that relaxin may play a role in the fetal abnormalities associated with pregnancy in type 1 diabetic women, we previously compared gestational relaxin concentrations in diabetic and clinically normal women using a porcine relaxin radioimmunoassay (RIA): Serum immunoactive relaxin was significantly (P < 0.001) elevated in the diabetic women. To confirm and extend this work in a larger group of subjects, we have now used an enzyme-linked immunosorbent assay (ELISA) specific for human H2 relaxin (the normal human gene product) to determine immunoactive serum relaxin concentrations in serial samples from 61 Type 1 diabetic and 21 normal pregnant women. Samples from 22 of the diabetic and nine of the normal women were also directly compared in the porcine relaxin RIA. ELISA-determined serum relaxin was higher (P < 0.001) at 24 and 36 weeks of pregnancy in type 1 diabetic women than in controls, confirming previous findings. However, the geometric mean increase in immunoactive relaxin concentration in identical samples from pregnant diabetic women over that of controls was significantly greater with the RIA than with the ELISA (271% vs 44%; P < 0.001). To investigate this discrepancy, the specificity and epitope selectivity of the RIA and the ELISA were compared using several synthetic polypeptides, including human relaxins H1 and H2, and relaxin and insulin derivatives. Both assays showed great specificity, but the porcine RIA selectively identified the epitopes of the receptor-binding domain of the relaxin B chain and cross-reacted strongly with H1 and H2 relaxins. In contrast, only the H2 peptide was detected by the ELISA antiserum. Therefore, the marked discrepancy between the RIA and the ELISA could be due to the presence in the diabetic samples of another relaxin-like molecule in addition to the normal H2 relaxin. The biological consequences of elevated serum relaxin in diabetic pregnancy remain to be elucidated.

Lipoprotein profiles and glucose tolerance in lean and obese chimpanzees.

Abstract: We compared serum lipid profiles and glucose tolerance of obese and lean chimpanzees maintained on a 10.9% fat diet. Seven of 14 obese and 6 of 17 lean chimpanzees were hypercholesterolemic (low density lipoprotein cholesterol > 160 mg/dl), three obese and three lean animals had total cholesterol/high density lipoprotein cholesterol ratios of 5.9–10.7, and two obese and one lean chimpanzee had abnormal glucose tolerance. Useful numbers of captive chimpanzees thus exhibit metabolic abnormalities without recourse to high fat diets and could serve as surrogates in studies of human metabolic diseases.

Pyrogenicity of Etiocholanolone and Interleukin-1 in New and Old World Monkeys

Abstract Etiocholanolone (5β-androstan-3α-ol-17-one; designated E) is one of the major products of metabolism of testosterone and androstenedione (androst-4-ene-3,17-dione) in many mammalian species, including humans. E and several other 5β-reduced steroids have been found to induce fever in humans. The pyrogenic effect of these steroids has been shown to be due to the release of interleukin-1 (IL-1) from the leukocytes that are mobilized in response to the steroid injections. Old World Monkeys such as Rhesus monkeys (Macaca mulatta), metabolize androgens similarly to humans, and E is a normal metabolite. However, New World Monkeys such as Squirrel monkeys (Saimiri sciureus), lack hepatic 5α- and 5β- steroid reductases and excrete androgens primarily in an unaltered state; E is not produced. Therefore, we postulate that Squirrel monkeys likewise may have lost the ability to respond to 17-ketosteroids such as E. To test this hypothesis, adult male Rhesus and Squirrel monkeys were treated with E, and their rectal temperatures were recorded over a 24-hr period. Rhesus monkeys exhibited a rise of up to 3° F following E injection. Squirrel monkeys, on the other hand, did not exhibit any increase in rectal temperature over the 24-hr period, even when doses up to 250 times the effective human dose were used. However, both species responded to injected IL-1α with a robust increase in rectal temperature. The data show that E is pyrogenic in Rhesus, but not Squirrel monkeys. The findings support the notion that injected E may induce release of IL-1 in Rhesus monkeys, but not in Squirrel monkeys.