Body mass index and mortality in men treated for locally advanced prostate cancer: An analysis of RTOG 85–31

5128

Background: Greater body mass index (BMI) is associated with shorter time to prostate-specific antigen (PSA) failure following radical prostatectomy. We investigated whether BMI is associated with prostate cancer-specific mortality (PCSM) in a large randomized trial of men treated with radiation therapy (RT) and androgen deprivation therapy (ADT) for locally advanced prostate cancer. Methods: Between 1987 and 1992, 945 eligible men with locally advanced prostate cancer were enrolled on a phase III trial (RTOG 85- 31) and randomized to RT and immediate goserelin (Arm I) or RT alone followed by goserelin at relapse (Arm II). Height and weight data were available at baseline for 788 (83%) subjects. Cox regression analyses were performed to evaluate the relationships between BMI and all-cause mortality, PCSM, and non-prostate cancer mortality. Covariates included age, race, treatment arm, history of prostatectomy, nodal involvement, Gleason score, clinical stage, and BMI. Results: The 5-year PCSM rate for men with BMI<25kg/m2 was 6.5%, compared to 13.1% and 12.2% in men with BMI=25-<30 and BMI=30, respectively (Gray’s p=0.005). In multivariable analyses, as shown in the Table , greater BMI was significantly associated with higher PCSM [for BMI=25-<30, hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.02–2.27, p=0.04; for BMI=30, HR 1.65, 95% CI 1.02–2.66, p=0.04]. BMI was not associated with non-prostate cancer or all-cause mortality. Conclusions: Greater baseline BMI is independently associated with higher PCSM in men with locally advanced prostate cancer. Further studies are warranted to evaluate the mechanism(s) for increased mortality and to assess whether weight loss after prostate cancer diagnosis alters disease course.

[Table: see text]

No significant financial relationships to disclose.

The impact of the duration of adjuvant hormonal therapy in patients with unfavorable prognosis prostate cancer treated with radiotherapy: Secondary analysis of RTOG 85–31

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Background: RTOG 85–31 was a Phase III trial of androgen suppression for life as an adjuvant to radiotherapy. However not all patients continued on the protocol-mandated long-term hormonal therapy despite no evidence of recurrent disease. This analysis correlates duration of adjuvant hormonal therapy and outcomes among patients who prematurely discontinued long-term hormonal therapy. Methods: The protocol mandated pelvic radiotherapy (60–66 Gy) followed by goserelin 3.6 mg monthly given indefinitely or until disease progression. To avoid potential bias due to early progression/death, only patients who were alive with no evidence of disease at the time of cessation of hormonal therapy were included. There were 377 analyzable patients. Patients were divided in groups based on the hormonal therapy duration (HTD), as follows: = 1 year (27.3%), 1< and =2 years (11.4%), 2< and =4 years (13.3%), 4< and =6 years (10.6%) and > 6 years (37.4%). End-points were overall survival, disease-free survival, disease-free survival with PSA <1.5 ng/mL, disease-specific survival, local failure and distant failure. Cox-proportional hazards regression model was used to test the outcomes among the 5 groups. Results: The median follow-up time of surviving patients is 11.27 years. Pretreatment characteristics by hormone duration groups were well balanced except for age. The median duration of adjuvant hormonal therapy was 3.59 years. For each outcome, there are statistically significant differences among the 5 HTD groups in all outcomes without adjusting for other covariates. Pairwise comparisons show that HTD > 6 year group is significantly associated with having an improved survival and fewer failure events than all other HTD groups (HR < 1, p-value <0.0001). Adjusted for age and stratification variables, the HTD>6 year group remains the only group significantly associated with having fewer failure events in all outcomes. Conclusions: Prolonged HTD of > 6 years is significantly associated with improvements in all end-points studied. Based on these data, decreasing HTD to < 6 years may have a detrimental effect in patients with unfavorable prostate cancer.

No significant financial relationships to disclose.

Beta-secretase (BACE1)-inhibiting stilbenoids from Smilax Rhizoma

In the course of searching for BACE1 (beta-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of Smilax Rhizoma (the dried rhizomes of Smilax china L.) showed potent inhibitory activity. The active compounds were identified as a trans/cis-resveratrol mixture, oxyresveratrol, veraphenol, and cis-scirpusin A. They were shown to non-competitively inhibit BACE1 with the Ki values of 5.4 x 10(-6), 5.4 x 10(-6), 3.4 x 10(-6), and 5.4 x 10(-6)M and IC(50) values of 1.5 x 10(-5), 7.6 x 10(-6), 4.2 x 10(-6), and 1.0 x 10(-5)M, respectively. The active compounds were less inhibitory to alpha-secretase (TACE) and other serine proteases such as chymotrypsin, trypsin, and elastase, suggesting that they were relatively specific inhibitors of BACE1.

CT findings of malarial spleen

Malaria is one of the most frequent causes of fever among travellers to tropical countries. We report the CT imaging findings of poor contrast enhancement of the spleen on arterial phase in a case of malaria presenting as splenomegaly. To the best of our knowledge, this is the first report of malarial spleen diagnosed by these CT results.

A new diterpenoid alkaloid from Aconitum jaluense

A new diterpenoid alkaloid, jaluenine (1), has been isolated from the roots of Aconitum jaluense. The structure of jaluenine was determined by spectroscopic methods including two dimensional NMR (1H-1H COSY, HMQC, HMBC, NOESY).

Looking for new targets for prostate cancer therapy: Nuclear factor kappa B and CXCR4 co-expression in prostate specimens from RTOG-8610

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Background: The transcription factor Nuclear Factor-kappa B (NFκB) promotes the production of angiogenic, anti-apoptotic and prometastatic factors that are involved in carcinogenesis. The chemokine receptor CXCR4, which is under the control of NFκB, has been implicated in regulating metastasis of breast, pancreatic, and prostate cancer. This retrospective cohort study evaluated the frequency and co-expression of NFκB and CXCR4 in human prostate cancer specimens. Methods: Paraffin embedded samples from a subset of patients in the RTOG 8610 trial underwent immunohistochemical staining for NFκB and CXCR4. This study compared radiotherapy plus hormonal therapy to radiation therapy alone. The amount of NFκB and CXCR4 was scored by a blinded pathologist for the percentage of cells stained (0 to 100%) and staining intensity (0 to 3+). Results: NFκB and CXCR4 status was determined for 55 and 63 patients, respectively. Both NFκB and CXCR4 status were available for 51 of these patients. Of these, 51% were 2/3+ for NFκB and 61% were 2/3+ for CXCR4. There was a trend towards correlation between CXCR4 and NFκB staining as 18 of the 36 patients who were 2/3+ positive for NFκB were 2/3+ for CXCR4. 10 of the 11 pts with 3+ NFκB had 2/3+ CXCR4. This was consistent with the understanding that CXCR4 is regulated by NFκB, but did not reach statistical significance (p = 0.1298). Neither NFκB or CXCR4 were statistically significantly prognostic factors in this small subset of patients. Conclusion: NFκB and CXCR4 are expressed in a significant number of patients with organ confined prostate cancer. Neither predicted outcomes in this analysis, which may be due to the small sample size. This data supports the notion that NFκB regulates CXCR4 expression in prostate cancer and that one or both may be potential new targets for therapeutic intervention. Studies in larger prospective studies to determine the utility of NFκB and CXCR4 as predictive biomarkers and/or therapeutic targets is warranted. [Table: see text]

No significant financial relationships to disclose.

Does timing of androgen deprivation influence radiation-induced toxicity? A secondary analysis of Radiation Therapy Oncology Group protocol 9413

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Background: We conducted a secondary analysis of RTOG 9413 to compare if the timing of antiandrogen-therapy, concomitant versus adjuvant, influences the incidence of rectal toxicity in whole pelvic radiotherapy. Methods: For the purpose of this secondary analysis, we analyzed the 2 of the 4 arms of the study, in which all patients received radiotherapy to the whole pelvis followed by a boost to the prostate and excluded the two arms that received prostate only radiotherapy. The 2 arms differed only in the timing of the total of 4 months of total androgen deprivation (TAD): arm I (320 patients), TAD was begun 2 months before the start of radiotherapy and continued during radiotherapy. Arm III (319 patients), TAD started immediately after the completion of radiotherapy. Both acute rectal and acute urinary toxicities (CTC v.2.0), testosterone (measured at baseline and yearly after) and other patients data were modeled using the multivariate logistic regression and the multivariate Cox-proportional hazards regression. Results: Median follow up for all patients is 6.0 and 5.8 years (arm I and II, resp.). 43 (13%) patients in each arm had abnormally low testosterone before start of TAD. Late grade 2 - 5 rectal toxicity occurred in 16% and 13% and urinary toxicity in 18% and 20% (arm I and II, resp.). Frequency (or occurrence) of late rectal toxicity (grade 0–1 vs. 2–5, p = 0.2170) and late urinary toxicity (grade 0–1 vs. 2–5, p = 0.4204) are not significantly different between the two arms. The only risk factors for late rectal toxicity in a multivariate regression model was acute rectal toxicity (OR 1.48, p = 0.025), but not abnormal testosterone level at baseline (p = 0.718) or treatment arm (p = 0.874). For late urinary toxicity: age (OR = 1.588, p = 0.010), RT field size (OR 1.004, p < 0.025), baseline testosterone (OR 1.718, p = 0.028), and acute (grade 2–4) toxicity (OR = 1.664, p = 0.006) but not treatment arm (p = 0.928) were risk factors. Conclusions: While late toxicity was not different for concomitant vs. adjuvant hormonal therapy, an abnormally low testosterone level at baseline is a risk factor for late urinary toxicity and not late rectal toxicity.

No significant financial relationships to disclose.

Effect of water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth and biofilm vitality

The purpose of the present study was to examine the effects of a newly developed water-soluble reduced chitosan on Streptococcus mutans, plaque regrowth, and biofilm vitality. A 1.0%, water-soluble reduced chitosan, with pH ranging from 6.0 to 6.5, molecular weights between 3,000 and 5,000 Da, and 70% degree of deacetylation, was used. To determine antibacterial and antiplaque potency of chitosan, minimal inhibitory concentrations (MICs) for S. mutans and S. sanguinis (formerly S. sanguis), short-term exposure to S. mutans, and clinical trial of plaque regrowth and biofilm vitality were conducted. Twelve dental students volunteered to participate in the 6-week, double blind, randomized clinical trial using the classical 4-day plaque regrowth design. The MIC of water-soluble reduced chitosan for S. mutans was 1.25 g/l. While the cells exposed to distilled water (DW) grew rapidly, with a maximum turbidity reached by 16 h postinoculation, S. mutans exposed to chitosan (5.0 g/l) exhibited a substantial delay in growth and reached a maximum turbidity by 32 h postinoculation. The chitosan solution reduced the plaque index and the vitality of the plaque flora significantly when compared to DW, but this was less than the reductions found with the positive control of 0.1% chlorhexidine solution. The water-soluble reduced chitosan exhibited potent antibacterial effect on S. mutans, and displayed a significant antibacterial and plaque-reducing action during the 4-day plaque regrowth.

Cytotoxic triterpenoides from Alismatis Rhizoma

Four prostane-type triterpenes were isolated from a methanol extract of Alismatis Rhizoma by bioassay-guided isolation using in vitro cytotoxic assay. The compounds were identified as alisol B 23-acetate (1), alisol C 23-acetate (2), alisol B (3), alisol A 24-acetate (4) by spectroscopic methods. Amongst the compounds, alisol B (3) showed significant cytotoxicity against SK-OV3, B16-F10, and HT1080 cancer cell lines with ED50 values of 7.5, 7.5, 4.9 microg/ml, respectively.

A new naphthoquinone from Pyrola japonica

A new naphthoquinone, 5,8-dihydro-2,7-dimethyl-[1,4]naphthoquinone (1), which was named 5,8-dihydrochimaphilin, isolated from an ethyl acetate soluble fraction from the root of Pyrola japonica, together with chimaphilin (2). Compound 1 was transformed rapidly to 2 upon exposure to air by HPLC analysis. This fact supported that chimaphilin (2) may be an artifact from 1.

A cytotoxic secocycloartenoid from Abies koreana

Two triterpenoids, 24-methylene-3,4-seco-cycloart-4(28)-en-3-oic acid (1) and 3-oxo-9beta-lanosta-7,22Z,24-trien-26,23-olide (6) were isolated from Abies koreana, together with beta-sitosterol (2), maltol (3), beta-sitosterol-O-beta-D-glucoside (4), and hexacosylferulate (5). The structures of the compounds were established based on the spectroscopic data. The cytotoxic activities of triterpenoids have been evaluated using the sulforhodamine B (SRB) method. Compound 1 showed moderate cytotoxicities against human lung carcinoma (A549), ovarian carcinoma (SK-OV-3), malignant melanoma (SK-MEL-2), and colon carcinoma (HCT-15) cell lines.

Differential functions of mPer1, mPer2, and mPer3 in the SCN circadian clock

The role of mPer1 and mPer2 in regulating circadian rhythms was assessed by disrupting these genes. Mice homozygous for the targeted allele of either mPer1 or mPer2 had severely disrupted locomotor activity rhythms during extended exposure to constant darkness. Clock gene RNA rhythms were blunted in the suprachiasmatic nucleus of mPer2 mutant mice, but not of mPER1-deficient mice. Peak mPER and mCRY1 protein levels were reduced in both lines. Behavioral rhythms of mPer1/mPer3 and mPer2/mPer3 double-mutant mice resembled rhythms of mice with disruption of mPer1 or mPer2 alone, respectively, confirming the placement of mPer3 outside the core circadian clockwork. In contrast, mPer1/mPer2 double-mutant mice were immediately arrhythmic. Thus, mPER1 influences rhythmicity primarily through interaction with other clock proteins, while mPER2 positively regulates rhythmic gene expression, and there is partial compensation between products of these two genes.

Resistance exercise training reduces hypertriglyceridemia in HIV-infected men treated with antiviral therapy

Hypertriglyceridemia, peripheral insulin resistance, and trunk adiposity are metabolic complications recently recognized in people infected with human immunodeficiency virus (HIV) and treated with highly active antiretroviral therapy (HAART). These complications may respond favorably to exercise training. Using a paired design, we determined whether 16 wk of weight-lifting exercise increased muscle mass and strength and decreased fasting serum triglycerides and adipose tissue mass in 18 HIV-infected men. The resistance exercise regimen consisted of three upper and four lower body exercises done for 1-1.5 h/day, 4 days/wk for 64 sessions. Dual-energy X-ray absorptiometry indicated that exercise training increased whole body lean mass 1.4 kg (P = 0.005) but did not reduce adipose tissue mass (P = NS). Axial proton-magnetic resonance imaging indicated that thigh muscle cross-sectional area increased 5-7 cm(2) (P < 0.005). Muscle strength increased 23-38% (P < 0.0001) on all exercises. Fasting serum triglycerides were decreased at the end of training (281-204 mg/dl; P = 0.02). These findings imply that resistance exercise training-induced muscle hypertrophy may promote triglyceride clearance from the circulation of hypertriglyceridemic HIV-infected men treated with antiviral therapy.

Platelet-activating factor (PAF)-dependent transacetylase and its relationship with PAF acetylhydrolases

Platelet-activating factor (PAF)-dependent transacetylase (TA) is an enzyme that transfers an acetyl group from PAF to acceptor lipids such as lysophospholipids and sphingosine. This enzyme is distributed in membrane and cytosol of the cells. We previously revealed that TA purified from rat kidney membrane showed an amino acid sequence similarity to that of bovine PAF-acetylhydrolase (AH) (II). In the present study, we purified TA from the rat kidney cytosol and analyzed its amino acid sequence. The amino acid sequence of the cytosolic TA is similar to that of bovine PAF-AH (II) and membrane TA. To clarify the relationship between TA and PAF-AH (II), we isolated cDNA of rat PAF-AH (II). The predicted amino acid sequence of rat PAF-AH (II) from isolated cDNA included all the sequences found in TAs purified from the membrane and cytosolic TAs. In addition, monoclonal antibody to recombinant PAF-AH (II) cross-reacted with both cytosolic and membrane TAs. Consistent with sequence identity, recombinant PAF-AH (II) showed TA activity, whereas recombinant PAF-AH Ib, which is a different subtype of intracellular PAF-AHs, did not possess TA activity. Analysis of a series of site-directed mutant PAF-AH (II) proteins showed that TA activity was decreased, whereas PAF-AH activity was not affected in C120S and G2A mutant proteins. Thus, Cys(120) and Gly(2) are implicated in the catalysis of TA reaction in this enzyme. Furthermore, the transfer of acetate from PAF to endogenous acceptor lipids was significantly increased in a time-dependent manner in CHO-K1 cells transfected with PAF-AH (II) gene. These results demonstrate that PAF-AH (II) can function, as a TA in intact cells, and PAF-AH (II) and TA are the same enzyme.

Role of follicular dendritic cells in the apoptosis of germinal center B cells

Follicular dendritic cells (FDCs) provide the most obvious source of antigens, which are essential for the differentiation of GC B cells. It has been reported that most proliferating B cells in germinal centers undergo apoptosis. Quantitative histology shows macrophages with apoptotic debris throughout the germinal center, the highest frequency of these cells being found in the dense FDC network. Based on these findings, we hypothesized that FDC may be involved in an apoptotic pathway of the germinal center B cells. To prove this hypothesis, we performed double immunohistochemical analysis using anti-FDC mAb and peanut agglutinin (PNA), with their respective TUNEL kits. Collated data showed that a great proportion of the apoptotic cells, most of which were positive for PNA, were in close contact with FDC, which indicated an interaction between FDC and B cells in the apoptotic pathway. Further studies using double immunohistochemical staining and FACS analyses demonstrated the expression of Fas-ligand (FasL) in a subset of the FDC. These results suggest that FDC may play a role in the apoptosis of germinal center B cells via Fas-FasL interaction.

Cytotoxic triterpenes from Crataegus pinnatifida

Bioassay-guided fractionation of Crataegus pinnatifida (Rosaceae) gave two cytotoxic ursane-type triterpenes which were identified as uvaol (1) and ursolic acid (2) by physicochemical and spectroscopic methods. 3-Oxo-ursolic acid (3) was synthesized from ursolic acid (2) by Jones method. The cytotoxic activities of these compounds were tested against murine L1210 and human cancer cell lines (A549, SK-OV-3, SK-MEL-2, XF498, and HCT15) in vitro. Compounds 1 and 2 showed moderate cytotoxicities against L1210, whereas they showed weak activities against human cancer cell lines. However, compound 3 exhibited potent cytotoxic activities both in murine and in human cancer cell lines.

dCLOCK is present in limiting amounts and likely mediates daily interactions between the dCLOCK-CYC transcription factor and the PER-TIM complex

In Drosophila melanogaster four circadian clock proteins termed PERIOD (PER), TIMELESS (TIM), dCLOCK (dCLK), and CYCLE (CYC/dBMAL1) function in a transcriptional feedback loop that is a core element of the oscillator mechanism. dCLK and CYC are members of the basic helix-loop-helix (bHLH)/PAS (PER-ARNT-SIM) superfamily of transcription factors and are required for high-level expression of per and tim and repression of dClk, whereas PER and TIM inhibit dCLK-CYC-mediated transcription and lead to the activation of dClk. To understand further the dynamic regulation within the circadian oscillator mechanism, we biochemically characterized in vivo-produced CYC, determined the interactions of the four clock proteins, and calculated their absolute levels as a function of time. Our results indicate that throughout a daily cycle the majority of the dCLK present in adult heads stably interacts with CYC, indicating that CYC is the primary in vivo partner of dCLK. dCLK-CYC dimers are bound by PER and TIM during the late evening and early morning, suggesting the formation of a tetrameric complex with impaired transcriptional activity. Although dCLK is present in limiting amounts and CYC is by far the most abundant of the four clock proteins that have been examined, PER and TIM appear to interact preferentially with dCLK. Our results suggest that dCLK is the main component regulating the daily abundance of transcriptionally active dCLK-CYC complexes.