Enniatin exerts p53-dependent cytostatic and p53-independent cytotoxic activities against human cancer cells

Worldwide, multiple Fusarium mycotoxins occur as contaminants of cereals with important impacts on human and animal health. The aim of this study was to investigate the effects of the widespread Fusarium secondary metabolite enniatin (ENN), a cyclic hexadepsipeptide, on human cell growth and survival. While short-term exposure (up to 8 h) to ENN at nanomolar concentrations slightly but significantly stimulated cell proliferation, it showed profound apoptosis-inducing effects especially against various human cancer cell types at low micromolar concentrations (already after 24 h of treatment). Several cellular changes indicative for programmed cell death such as cell shrinkage, chromatin condensation, DNA fragmentation, and apoptotic body formation were observed. Correspondingly, the cleavage of poly(ADP-ribosyl)polymerase and the activation of multiple caspases accompanied a distinct loss of mitochondrial membrane potential. To investigate the impact of apoptosis- and cell cycle-regulating proteins on ENN activity, HCT116 cells with homozygously disrupted p53, p21, or bax genes were analyzed. In vitality assays, no significant influences of these proteins on the anticancer activity of ENN were detectable. In contrast, 3H-thymidine incorporation revealed a significantly more efficient block of DNA synthesis in p53 wild-type as compared to knock-out cells. Accordingly, fluorescence-activated cell sorting analysis demonstrated a stronger ENN-induced cell cycle arrest in the G0/G1 phase. Profound ENN-mediated induction of p53 and the p53-downstream cell cycle inhibitor p21 were detectable in p53 wild-type cells by Western blotting. P53-independent p21 induction was also detectable at higher ENN concentrations in p53 (-/-) cells. In contrast, bax activation by ENN was independent of the cellular p53 status. In summary, our results suggest that short-term exposure to very low ENN concentrations, for example, via food intake, might have tumor-promoting functions based on growth stimulation. In contrast, elevated ENN concentrations exert profound p53-dependent cytostatic and p53-independent cytotoxic activities especially against human cancer cells, suggesting a potential quality of ENN as an anticancer drug.     

Associations between herpes simplex virus type 2 and HCV With HIV among injecting drug users in New York City: the current importance of sexual transmission of HIV

Objectives. We examined relationships between herpes simplex virus type 2 (HSV-2), a biomarker for sexual risk, and HCV, a biomarker for injecting risk, with HIV among injecting drug users (IDUs) who began injecting after large-scale expansion of syringe exchange programs in New York City.Methods. We recruited 337 heroin and cocaine users who began injecting in 1995 or later from persons entering drug detoxification. We administered a structured interview covering drug use and HIV risk behavior and collected serum samples for HIV, HCV, and HSV-2 testing.Results. HIV prevalence was 8%, HSV-2 39%, and HCV 55%. We found a significant association between HSV-2 and HIV (odds ratio [OR] = 7.9; 95% confidence interval [CI] = 2.9, 21.4) and no association between HCV and HIV (OR = 1.14; 95% CI = 0.5, 2.6). Black IDUs had the highest prevalence of HSV-2 (76%) and HIV (24%) but the lowest prevalence of HCV (34%).Conclusions. Most HIV infections among these IDUs occurred through sexual transmission. The relative importance of injecting versus sexual transmission of HIV may be critical for understanding racial/ethnic disparities in HIV infection.Persons who inject drugs, or injecting drug users (IDUs), are at risk for HIV infection through both multiperson use (sharing) of needles and syringes and unprotected sex. Sharing needles and syringes is a considerably more efficient mode of HIV transmission than is heterosexual intercourse,^1,2 so in most epidemiological situations, injecting-related transmission is much more important than is sexual transmission. This relative efficiency of transmission is reflected in the current Centers for Disease Control and Prevention transmission classification system, in which persons with both injecting drug risk and heterosexual risk behavior are placed in the injecting drug use transmission category only.³However, several factors may change the relative importance of injecting versus sexual transmission of HIV among IDUs. First, programs to prevent injecting-related transmission can be quite effective. In areas where combined HIV prevention programs (including syringe exchange, drug abuse treatment, community outreach, and voluntary HIV counseling and testing)⁴ have been implemented, injecting-related transmission has been substantially reduced and sexual transmission can be more important among IDUs. This effect appears to have occurred in Amsterdam^5,6 and Chicago.⁷Second, use of certain drugs may be associated with unsafe sexual behaviors and thus increase the importance of sexual transmission of HIV in populations of injecting and noninjecting drug users. Crack cocaine^8,9 and, more recently, methamphetamine^10,11 are probably the 2 most important examples of this phenomenon.Third, some sexually transmitted diseases, such as syphilis and herpes simplex virus type 2 (HSV-2), may increase HIV transmission among both injecting and noninjecting drug users. There is considerable biological and epidemiological evidence that HSV-2 infection facilitates both acquiring and transmitting HIV. Two meta-analyses and a recent qualitative review have concluded that prevalent HSV-2 infection is associated with a two- to threefold increased likelihood of acquiring HIV.^12–14 Although most research on HSV-2 and HIV has been conducted in Africa, several studies indicate positive associations between HSV-2 and HIV among injecting and noninjecting drug users in the United States.¹⁵ Because HSV-2 is transmitted sexually but not through sharing drug injection equipment, it can be used as a biomarker for sexual risk among IDUs.¹⁶Assessing the relative importance of injecting versus sexual transmission of HIV among IDUs may also have great importance for understanding racial/ethnic differences in HIV infection among injecting and noninjecting drug users.We examined relationships between HSV-2 and HIV among IDUs who began injecting after arge-scale implementation of syringe exchange programs from 1992 to 1998 in New York City. The expanded programs included not only a much greater volume of syringes exchanged but also increases in services such as voluntary HIV counseling and testing and referrals to drug abuse treatment. Thus, the large-scale expansion of the syringe exchange programs can be seen as the beginning of combined HIV prevention programs for IDUs^17–19 in New York City. The expansion of the syringe exchange programs was followed by a reduction in HIV incidence from approximately 4/100 person-years to 1/100 person-years among IDUs in New York City.²⁰We chose the term “persons who inject drugs,” which emphasizes that these individuals should be considered persons first and that they are much more than the behavior of injecting drug use. However, we address official classification of HIV transmission routes, so we use the current standard terms “injecting drug use” and “injecting drug users” and the abbreviation “IDU.” We want to emphasize that HIV prevention for persons who inject drugs should fully consider their human rights.     

Inverse association between lipid levels and mortality in men with chronic kidney disease who are not yet on dialysis: effects of case mix and the malnutrition-inflammation-cachexia syndrome

High total cholesterol is associated with lower mortality in dialysis patients, but the relationship between lipid levels and mortality in patients who have chronic kidney disease (CKD) and are not yet on dialysis is poorly described. This study examined the association between lipid levels and all-cause and cardiovascular mortality in 986 male patients (age 67.4 +/- 10.9 yr; race 23.7% black) who had CKD and were not yet on dialysis. Associations were determined in fixed-covariate and time-dependent Cox models, before and after adjustment for components of case mix and surrogates for malnutrition-inflammation-cachexia syndrome (MICS). Lower total cholesterol quartiles were associated with higher all-cause mortality in a fixed-covariate model that was adjusted for age, race, and body mass index (hazard ratio [95% confidence interval] for cholesterol <153, 153 to 182, and 183 to 215 versus >215 mg/dl: 1.91 [1.35 to 2.69], 1.36 [0.96 to 1.92], 1.10 [0.78 to 1.57]; P < 0.001 for trend), but this association was attenuated after adjustment for case mix (P = 0.023 for trend) and abolished after additional adjustment for MICS (P = 0.14 for trend), with time-dependent Cox models showing similar results. Similar tendencies also were detected in the association between levels of LDL cholesterol with total and cardiovascular mortality and triglycerides with all-cause mortality in both fixed-covariate and time-dependent analyses. Lower lipid levels are associated with higher mortality in patients who have moderate and advanced CKD and are not yet on dialysis. This inverse association is explained in part by case-mix characteristics and the presence of surrogates for MICS.     

When the spirit leaves: Childhood death, grieving, and bereavement in Islam

The death of a child has a profound and often long-lasting impact on families. The parent's relationship and their ability to bond with and take care of surviving children may be affected. It is important for healthcare workers to understand the dynamics associated with bereavement, especially when the family comes from a non-Western culture. Islam is one of the three most populous religions along with Christianity and Hinduism and the fastest growing religion in the United States but remains largely misunderstood. This paper seeks to explain what Islam is, who is a Muslim, where they live, and what they believe and practice. It also explains how Islamic beliefs contextualize the meaning of life and death for Muslims and how they are exhorted to grieve upon a child's death. Reading this paper will enable those who care for Muslim families to better attend to the social and emotional needs of Muslim parents and siblings after such a tragic event.     

Vitamin D inhibits the formation of prostatic intraepithelial neoplasia in Nkx3.1;Pten mutant mice.

PURPOSE: Epidemiologic studies have shown that reduced levels of vitamin D represent a major risk factor for prostate cancer. In this report, we have examined the efficacy of 1alpha,25-dihydroxyvitamin D(3) (1,25 D(3)) as a chemopreventive agent using Nkx3.1; Pten mutant mice, which recapitulate stages of prostate carcinogenesis from prostate intraepithelial neoplasia (PIN) to adenocarcinoma. EXPERIMENTAL DESIGN: 1,25 D(3) (or vehicle) was delivered continuously to Nkx3.1; Pten mutant or control mice for a 4-month period beginning before (precancerous cohort) or after (cancerous cohort) these mice developed PIN. At the conclusion of the study, the mice were analyzed for the occurrence of PIN and/or cancer phenotypes by histologic analyses and immunostaining using known markers of cancer progression in these mice. RESULTS: We found that sustained delivery of 1,25 D(3) to the Nkx3.1; Pten mutant mice resulted in a significant reduction in the formation of PIN while having no apparent effect on the control mice. Furthermore, 1,25 D(3) was maximally effective when delivered before, rather than subsequent to, the initial occurrence of PIN. We further show that this 1,25 D(3)-mediated inhibition of PIN was coincident with up-regulation of vitamin D receptor expression in the prostatic epithelium of the mutant mice, as well as in CASP prostate epithelial cell lines developed from these mice, while having no effect on androgen receptor expression or androgen receptor signaling. CONCLUSION: Our findings show the value of chemoprevention studies using Nkx3.1; Pten mutant mice, particularly for evaluating the efficacy and underlying mechanisms of potential agents and to gain insights about the optimal timing of their delivery. In particular, our study predicts that vitamin D may have differential effects during early-stage versus late-stage disease and that it is more likely to be beneficial if delivered either before the overt manifestation of clinically detectable disease or during the earliest disease stages, rather than in advanced disease. Thus, our findings support the assessment of vitamin D analogues for chemoprevention in clinical trials targeting patients with early-stage disease and also establish molecular markers that can be used in such trials to determine biological activity and to optimize further clinical trials.     

Mechanism and novel therapeutic approaches to wasting in chronic disease

Cachexia is a multifactorial syndrome defined by continuous loss of skeletal muscle mass – with or without loss of fat mass – which cannot be fully reversed by conventional nutritional support and which may lead to progressive functional impairment and increased death risk. Its pathophysiology is characterized by negative protein and energy balance driven by a variable combination of reduced food intake and abnormal metabolism. Muscle wasting is encountered in virtually all chronic disease states in particular during advanced stages of the respective illness. Several pre-clinical and clinical studies are ongoing to ameliorate this clinical problem. The mechanisms of muscle wasting and cachexia in chronic diseases such as cancer, chronic heart failure, chronic obstructive pulmonary disease and chronic kidney disease are described. We discuss therapeutic targets and such potential modulators as appetite stimulants, selective androgen receptor modulators, amino acids and naturally occurring peptide hormones.     

MiR-34 by targeting p53 induces apoptosis and DNA damage in paclitaxel-resistant human oral squamous carcinoma cells

MicroRNA-34 (miR-34) is one the most important tumor suppressor miRNAs involving in the various aspects of oral cancer. The present study aimed to evaluate the effects of miR-34 restoration in OECM-1 oral cancer resistant to paclitaxel (OECM-1/PTX) and its underlying mechanisms through p53-mediated DNA damage and apoptosis. OECM-1 and OECM-1/PTX were transfected with miR-34 mimic and inhibitor. Cellular proliferation and apoptosis were evaluated through MTT assay and flow cytometry, respectively. The mRNA and protein expression levels of p53, p-glycoprotein (P-gp), ATM, ATR, CHK1, and CHK2 were assessed through qRT-PCR and western blotting. Rhodamin123 uptake assay was used to measure the P-gp activities. P53 expression was also suppressed by sing a siRNA transfection of cells. The expression levels of miR-34 were downregulated in OECM-1/PTX. Restoration of miR-34 led to increase in cytotoxic effects of paclitaxel in cells. In addition, the expression levels and activities of P-gp were reduced following miR-34 transfection. miR-34 transfection upregulated the p53, ATM, ATR, CHK1, and CHK2 expression levels in OECM-1/PTX cells. Furthermore, cells transfected with miR-34 showed higher levels of apoptosis. miR-34 restoration reverses paclitaxel resistance in OECM-1 oral cancer. The chemosensitive effects of miR-34 is mediated through increasing DNA damage and apoptosis in a p53 depended manner.