Histone methyltransferase DOT1L coordinates AR and MYC stability in prostate cancer

The histone methyltransferase DOT1L methylates lysine 79 (K79) on histone H3 and is involved in Mixed Lineage Leukemia (MLL) fusion leukemogenesis; however, its role in prostate cancer (PCa) is undefined. Here we show that DOT1L is overexpressed in PCa and is associated with poor outcome. Genetic and chemical inhibition of DOT1L selectively impaired the viability of androgen receptor (AR)-positive PCa cells and organoids, including castration-resistant and enzalutamide-resistant cells. The sensitivity of AR-positive cells is due to a distal K79 methylation-marked enhancer in the MYC gene bound by AR and DOT1L not present in AR-negative cells. DOT1L inhibition leads to reduced MYC expression and upregulation of MYC-regulated E3 ubiquitin ligases HECTD4 and MYCBP2, which promote AR and MYC degradation. This leads to further repression of MYC in a negative feed forward manner. Thus DOT1L selectively regulates the tumorigenicity of AR-positive prostate cancer cells and is a promising therapeutic target for PCa.

Histone methyltransferase, DOTL1 is implicated in the pathogenesis of MLL-rearranged leukemia, however, not much is known of its role in prostate cancer (PCa). Here, the authors report that DOTL1 inhibition suppresses both androgen receptor and MYC pathways in a negative feed forward manner to reduce growth of AR-positive PCa.

Comparison of e-cigarette marketing and availability in tobacco retail outlets among diverse low-income communities in California

OBJECTIVE

Research examining marketing and availability of electronic cigarettes (e-cigarettes) within tobacco retail stores is limited, especially among vulnerable communities. However, tobacco retailers tend to be the first point of access to e-cigarette exposure, especially among youth. In response, store observations were conducted among tobacco retailers across five ethnically diverse, low-income communities.

DESIGN

Trained community health workers recorded the presence of e-cigarette products, marketing, self-service displays, product pricing and product placement in the tobacco retail environment across American-Indian Tribal lands in California (n=96) and low-income African-American, Hispanic/Latino (HL), Korean-American (KA) and Non-Hispanic White (NHW) communities in Southern California (n=679) from January 2016 to January 2017. Store characteristics and pricing were analysed by ethnic community.

RESULTS

Compared with retailers in NHW communities, retailers across all other communities were less likely to sell e-cigarette and flavoured e-cigarette products and were less likely to have self-service displays. Compared with retailers in NHW communities, retailers across all other communities were less likely to have e-cigarettes placed near youth-friendly items, while retailers in KA and HL communities were less likely to have exterior advertising compared with retailers in NHW communities.

CONCLUSIONS

Findings indicate differences in e-cigarette availability and marketing by ethnic community. In addition, placement of products and marketing that expose youth to e-cigarette and other tobacco products within the retail environment should be restricted and regulated by policymakers and tobacco regulatory agencies to reduce the burden of tobacco-related diseases among vulnerable populations.

Proteomic analyses of monocyte-derived macrophages infected with human immunodeficiency virus type 1 primary isolates from Hispanic women with and without cognitive impairment

The signature for human immunodeficiency virus type 1 (HIV-1) neurovirulence remains a subject of intense debate. Macrophage viral tropism is one prerequisite but others, including virus-induced alterations in innate and adaptive immunity, remain under investigation. HIV-1-infected mononuclear phagocytes (MPs; perivascular macrophages and microglia) secrete toxins that affect neurons. The authors hypothesize that neurovirulent HIV-1 variants affect the MP proteome by inducing a signature of neurotoxic proteins and thus affect cognitive function. To test this hypothesis, HIV-1 isolates obtained from peripheral blood of women with normal cognition (NC) were compared to isolates obtained from women with cognitive impairment (CI) and to the laboratory adapted SF162, a spinal fluid R5 isolate from a patient with HIV-1-associated dementia. HIV-1 isolates were used to infect monocyte-derived macrophages (MDMs) and infection monitored by secreted HIV-1 p24 by enzyme-linked immunosorbent assay (ELISA). Cell lysates of uninfected and HIV-1-infected MDMs at 14 days post infection were fractionated by cationic exchange chromatography and analyzed by surface enhanced laser desorption ionization time of flight (SELDI-TOF) using generalized estimating equations statistics. Proteins were separated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1D SDS-PAGE) and identified by tandem mass spectrometry. Levels of viral replication were similar amongst the HIV-1 isolates, although higher levels were obtained from one viral strain obtained from a patient with CI. Significant differences were found in protein profiles between virus-infected MDMs with NC, CI, and SF162 isolates (adjusted P value after multiple testing corrections, or q value <.10). The authors identified 6 unique proteins in NC, 7 in SF162, and 20 in CI. Three proteins were common to SF162 and CI strains. The MDM proteins linked to infection with CI strains were related to apoptosis, chemotaxis, inflammation, and redox metabolism. These findings support the hypothesis that the macrophage proteome differ when infected with viral isolates of women with and without CI.

Diffusion tensor imaging in preclinical and presymptomatic carriers of familial Alzheimer's disease mutations

Measures are needed that identify persons that will develop Alzheimer's disease in order to target them for preventative interventions. There is evidence from animal, pathological and imaging studies that disruption of white matter occurs in the course of Alzheimer's disease and may be an early event. Prior studies have suggested that late-myelinating regions or white matter connecting limbic structures are particularly susceptible to degradation. Persons destined to develop the disease by virtue of fully penetrant genetic alterations (familial Alzheimer's disease or FAD) provide a model in which early and even presymptomatic changes of the disease may be identified. In this study we performed diffusion tensor imaging (DTI) on 2 demented and 21 subjects at-risk for inheriting an FAD mutation. We compared global and localized fractional anisotropy (FA) measures in white matter between FAD mutation carriers and non-carriers in the preclinical (clinical dementia rating <1, n = 20) and presymptomatic (clinical dementia rating = 0, n = 15) stages of the disease. There were no significant differences between mutation carriers and non-carriers with regard to absolute age, age relative to the typical age of disease diagnosis in their family, gender or Mini-Mental Status Examination Score. Among preclinical FAD mutation carriers (n = 12), mean whole brain white-matter FA (P = 0.045), FA of the columns of the fornix (P = 0.012), area of the perforant pathways bilaterally (right side: P = 0.028, left side: P = 0.027) and left orbitofrontal lobe (P = 0.024) were decreased relative to that of non-carriers (n = 8). We also found that FA in the columns of the fornix (P = 0.008) and left orbitofrontal lobe white matter (P = 0.045) were decreased in the eight presymptomatic mutation carriers compared to seven non-carriers. Logistic regression demonstrated that FA of the columns of the fornix was a better predictor of mutation status than was cross-sectional area of the fornix, global mean white-matter FA and left frontal lobe white-matter FA. In a linear regression analysis, white-matter volume (P = 0.002), hippocampal volume (P = 0.023) and mutation status (P = 0.032) significantly predicted fornix FA. We conclude that FA is decreased in the white matter in preclinical and even presymptomatic FAD mutation carriers, particularly in the late-myelinating tracts connecting limbic structures. Decreased FA in of the columns of the fornix is particularly robust in early FAD and may provide a biomarker for early disease in sporadic Alzheimer's disease.

Performance on MMSE sub-items and education level in presenilin-1 mutation carriers without dementia

BACKGROUND

Spanish-language screening tests that are sensitive to the early cognitive changes of Alzheimer's disease (AD) are needed. Persons known to be at 50% risk for young-onset AD due to presenilin-1 (PSEN1) mutations provide the opportunity to assess which measures on the Mini-mental State Examination (MMSE) are most sensitive to these early changes.

METHODS

We performed genetic and Spanish-language cognitive testing on 50 Mexican persons without dementia at risk for inheriting PSEN1 mutations. We then compared the performance on sub-items of the MMSE between PSEN1 mutation carriers (MCs) and non-carriers (NCs) using t-tests and Fisher's exact tests. Exploratory multiple logistic regression analyses were also performed.

RESULTS

Twenty-nine persons were MCs and 21 NCs. NCs tended to achieve higher levels of education (p = 0.039) than did MCs. MCs tended to perform more poorly when spelling "MUNDO" backwards and on Orientation, particularly regarding the date. In multiple regression analyses the ability of backwards spelling to predict PSEN1 mutation status was reduced when education was included as an independent variable.

CONCLUSION

Subjects in the earliest stage of PSEN1-related AD showed deficits on orientation to date and in divided attention when spelling backwards. It is unclear if educational level should be considered an associated feature or a con-founding variable in this population although it should be taken into account when considering performance on the MMSE task of divided attention. The relative lack of deficits on delayed recall of three words probably represents the insensitivity of this measure in early AD. This study supports the utility of autosomal dominant AD as a model of the more common sporadic form of the disorder.

Neuropsychological function in nondemented carriers of presenilin-1 mutations

BACKGROUND

Prospective and case-control studies have demonstrated that memory loss and executive dysfunction occur early in Alzheimer disease (AD).

OBJECTIVE

To investigate these observations by the study of persons at risk for autosomal dominant forms of AD.

METHODS

Neuropsychological and genetic tests were performed on 51 nondemented at-risk members of 10 Mexican families with two distinct presenilin-1 (PS1) mutations. Test scores were compared between PS1 mutation carriers (MCs; n = 30) and noncarriers (NCs; n = 21) by analyses of variance, co-varying for family and specific mutation. Regression analyses were performed, taking into account age relative to the median age at dementia diagnosis in the family (adjusted age), gender, Beck Depression Inventory (BDI) scores, education, and number of APOE epsilon4 alleles. Subjects were divided into age tertiles and scores compared within these groups. Composite scores for Verbal Memory, Executive Function/Working Memory, Language, and Visuospatial Function were created, and these scores compared between MCs and NCs.

RESULTS

MCs performed worse than NCs on the Mini-Mental State Examination, Trails Making Tests A and B, Delayed Recall of a 10-Word List, and Wechsler Adult Intelligence Scale WAIS Block Design. In multiple linear regression analyses, BDI score, gender, and number of APOE epsilon4 alleles did not consistently affect test scores. The differences seen between MCs and NCs were due to differences in the oldest tertile. MCs had lower Visuospatial and Executive Function/Working Memory but not Verbal Memory or Language composite scores.

CONCLUSIONS

This study is consistent with findings in sporadic Alzheimer disease of early problems with memory, visuospatial function, and particularly with executive function in PS1 mutation carriers. Depression, gender, and presence of an APOE epsilon4 allele did not demonstrate large influences on neuropsychological performance.

Non drug use- and drug use-specific spirituality as one-year predictors of drug use among high-risk youth

The present article explored two different dimensions of spirituality that might tap negative and positive relations with adolescent drug use over a 1-year period. Non-drug-use-specific spirituality measured how spiritual the person believes he or she is, participation in spiritual groups, and engagement in spiritual practices such as prayer, whereas drug-use-specific spirituality measured using drugs as a spiritual practice. Self-report questionnaire data were collected during 1997-1999 from a sample of 501 adolescents in 18 continuation high schools across southern California. Participants ranged in age from 14 to 19 and were 57% male, with an ethnic distribution of 34% White, 49% Latino, 5% African American, 7% Asian, and 5% other. A series of general linear model analyses were conducted to identify whether or not two different spirituality variables predict drug use (cigarettes, alcohol, marijuana, hallucinogens, and stimulants) at 1-year follow-up. After controlling for baseline drug use, non-drug-use-specific spirituality was negatively predictive of alcohol, marijuana, and stimulant use, whereas drug-use-specific spirituality failed to be found predictive of these variables one year later. Conversely, drug-use-specific spirituality was positively predictive of cigarette smoking and hallucinogen use, whereas non-drug-use spirituality failed to be found predictive of these variables. Our results provide new evidence that suggests that spirituality may have an effect on drug use among adolescents. The drug-use-specific measure of spirituality showed "risk effects" on drug use, whereas the other measure resulted in "protective effects," as found in previous research. Knowledge of the risk and protective patterns and mechanisms of spirituality may be translated into future drug use prevention intervention programs.

Female preclinical presenilin-1 mutation carriers unaware of their genetic status have higher levels of depression than their non-mutation carrying kin

OBJECTIVES

To study depressive symptoms in preclinical presenilin-1 (PS1) related Alzheimer's disease.

METHODS

Participants were 33 Mexican women at risk for inheriting PS1 mutations who were not demented. They were interviewed, underwent cognitive testing, and completed the Beck depression inventory (BDI). PS1 mutation status was determined. Mean BDI scores were compared between PS1 mutation carriers and non-carriers. The percentage of subjects who reported seeing a psychiatric professional, and the percentage complaining of memory loss were compared between groups. Regression analysis was used to determine whether mutation status predicted BDI scores after adjusting for age, education, mini-mental state examination, and subjective memory function.

RESULTS

PS1 mutation carriers (n = 17) scored significantly higher than non-carriers (n = 16) on the BDI (mean score, 14.4 v 6.5, p = 0.017); 24% of mutation carriers and 12.5% of non-carriers admitted having sought help from a psychiatric professional (NS). Mutation status remained a significant predictor of BDI scores after adjusting for potential covariates. Though not demented, mutation carriers tended to score lower than non-carriers on several neuropsychological tests.

CONCLUSIONS

Depressive symptoms can occur early in the course of PS1 related Alzheimer's disease, at least in women. This supports the hypothesis that depression may occur as a direct result of the neuropathology underlying Alzheimer's disease.

The prevalence and correlates of neuropsychiatric symptoms in a population with Parkinson's disease in Mexico

OBJECTIVE

To study the incidence of behavioral abnormalities in patients with Parkinson's disease (PD) and extend them to a Mexican population.

BACKGROUND

Reports from the US and Europe suggest depression, anxiety, and apathy occur with increased frequency in PD, but data on the occurrence of neuropsychiatric symptoms in patients with PD in Latin America are lacking.

METHODS

The investigators performed a cross-sectional survey of psychiatric symptoms and cognitive status in 40 patients with PD and 83 controls in Mexico City.

RESULTS

Results were compared between groups and correlations sought between symptoms and disease variables. Patients with PD had a higher rate of dysphoria, anxiety, and apathy (p < 0.001). Within the patients with PD, there was a positive correlation between disease severity (rho = 0.496), age (rho = 0.340), and degree of self-rated depression.

CONCLUSIONS

This study confirmed the observation previously described in other PD populations of increased rates of dysphoria, anxiety, and apathy in Mexican patients with PD. We found no relation between disease duration, severity, cognitive impairment, and neuropsychiatric symptoms as measured on the Neuropsychiatric Inventory, possibly a result of the relative lack of advanced cases in our population.

Oral versus vaginal misoprostol for cervical priming in first-trimester abortion: a randomized trial

The objective of this study was to compare the oral and vaginal administration of misoprostol for cervical priming before surgical abortion up to 63 days' gestation. A total of 900 pregnant women, with ages ranging from 18 to 42 years, who asked for pregnancy termination, were included in this study. Women were randomly allocated to one of the following groups: oral administration of 400 microg misoprostol, 8 h before aspiration; and vaginal self-administration of 400 microg misoprostol, 4 h before aspiration. During admission, all subjects were checked on a 15-min basis. The preoperative cervical dilatation achieved was the main outcome assessed. The cervix was dilated (Hegar > or = 8) in 348 (78%) subjects from the oral treatment group and in 391 (87%) women from the vaginal treatment group; this difference was statistically significant (p = 0.0004). The mean dilatation achieved in the oral treatment group was 8.1 mm (SD 1.6 mm) and it was 8.5 mm (SD 1.5 mm) in the vaginal treatment group; this difference was statistically significant (p = 0.0001). The frequencies of side-effects such as nausea, vomiting, diarrhea and chills reported by women from the vaginal misoprostol group were 10, 8, 18 and 4 times lower, respectively, than those reported by subjects from the oral misoprostol group. In conclusion, vaginal self-administration of misoprostol was the best administration route, as it obtained the same or greater priming effectiveness of the cervix in half the time with a much lower frequency of side-effects.

Disruption of hsp90 function results in degradation of the death domain kinase, receptor-interacting protein (RIP), and blockage of tumor necrosis factor-induced nuclear factor-kappaB activation

The death domain kinase, receptor interacting protein (RIP), is one of the major components of the tumor necrosis factor receptor 1 (TNFR1) complex and plays an essential role in tumor necrosis factor (TNF)-mediated nuclear factor kappaB (NF-kappaB) activation. The activation of NF-kappaB protects cells against TNF-induced apoptosis. Heat-shock proteins (Hsps) are chaperone molecules that confer protein stability and help to restore protein native folding following heat shock and other stresses. The most abundant Hsp, Hsp90, is also involved in regulating the stability and function of a number of cell-signaling molecules. Here we report that RIP is a novel Hsp90-associated kinase and that disruption of Hsp90 function by its specific inhibitor, geldanamycin (GA), selectively causes RIP degradation and the subsequent inhibition of TNF-mediated IkappaB kinase and NF-kappaB activation. MG-132, a specific proteasome inhibitor, abrogated GA-induced degradation of RIP but failed to restore the activation of IkappaB kinase by TNF, perhaps because, in the presence of GA and MG-132, RIP accumulated in a detergent-insoluble subcellular fraction. Most importantly, the degradation of RIP sensitizes cells to TNF-induced apoptosis. These data indicate that Hsp90 plays an important role in TNF-mediated NF-kappaB activation by modulating the stability and solubility of RIP. Thus, inhibition of NF-kappaB activation by GA may be a critical component of the anti-tumor activity of this drug.

The distinct roles of TRAF2 and RIP in IKK activation by TNF-R1: TRAF2 recruits IKK to TNF-R1 while RIP mediates IKK activation

The death domain kinase RIP and the TNF receptor-associated factor 2 (TRAF2) are essential effectors in TNF signaling. To understand the mechanism by which RIP and TRAF2 regulate TNF-induced activation of the transcription factor NF-kappaB, we investigated their respective roles in TNF-R1-mediated IKK activation using both RIP-/- and TRAF2-/- fibroblasts. We found that TNF-R1-mediated IKK activation requires both RIP and TRAF2 proteins. Although TRAF2 or RIP can be independently recruited to the TNF-R1 complex, neither one of them alone is capable of transducing the TNF signal that leads to IKK activation. Moreover, we demonstrated that IKK is recruited to the TNF-R1 complex through TRAF2 upon TNF treatment and that IKK activation requires the presence of RIP in the same complex.

Cleavage of the death domain kinase RIP by caspase-8 prompts TNF-induced apoptosis

Although the molecular mechanisms of TNF signaling have been largely elucidated, the principle that regulates the balance of life and death is still unknown. We report here that the death domain kinase RIP, a key component of the TNF signaling complex, was cleaved by Caspase-8 in TNF-induced apoptosis. The cleavage site was mapped to the aspartic acid at position 324 of RIP. We demonstrated that the cleavage of RIP resulted in the blockage of TNF-induced NF-kappaB activation. RIPc, one of the cleavage products, enhanced interaction between TRADD and FADD/MORT1 and increased cells' sensitivity to TNF. Most importantly, the Caspase-8 resistant RIP mutants protected cells against TNF-induced apopotosis. These results suggest that cleavage of RIP is an important process in TNF-induced apoptosis. Further more, RIP cleavage was also detected in other death receptor-mediated apoptosis. Therefore, our study provides a potential mechanism to convert cells from life to death in death receptor-mediated apoptosis.

Neuropsychological changes in subjects at risk of inheriting Alzheimer's disease

Subjects from four Mexican families at risk of inheriting Alzheimer's disease (AD) were studied using a complete neuropsychological battery. These tests were repeated and compared 1 year later. Some of the experimental subjects belong to an international protocol on molecular chromosomal study. A control group matched in age and schooling was included. The subjects at risk underwent a complete physical, neurological and neuropsychological assessment. A neuropsychological battery of cognitive domains designed for the the study of dementia syndromes was administered to all subjects. Six of the subjects showed abnormal performance in cognitive functions, memory, visuospatial functions or language which persisted 1 year later. The present work describes the initial findings of a long-term prospective study aimed at delineating the neuropsychological profile of subjects at risk and to validate subtle abnormalities which in some cases could be the incipient changes of AD.

Neurinoma of the trigeminal root and atypical trigeminal neuralgia: case report and review of the literature

BACKGROUND

Neurinomas of the trigeminal nerve are a rare entity: those located in the posterior fossa account for 20% of all cases. In the majority of cases, the clinical presentation begins with fifth cranial nerve involvement producing a constant pain associated with other cranial nerve palsy and cerebellar signs.

METHODS

We report the clinical features, neuroradiological imagings, and management of a case of trigeminal neurinoma located in the cerebellopontine angle, arising from the Vth cranial nerve root, presenting with an atypical trigeminal neuralgia; moreover, we analyze similar cases reported in the literature and we discuss whether pain can be produced by a neurinoma that arises central to the ganglion.

RESULTS

The tumor presented with an atypical trigeminal neuralgia characterized by constant trigeminal pain with paroxystical burns, hyperesthesia and hyperactive autonomic dysfunction. Neuroradiological examinations provided the best preoperative localization of this lesion, allowing better planning of the surgical approach, considering the large size of this tumor. A retromastoid incision and posterior fossa craniectomy approach was used, with complete excision of the tumor. The paraxysmal sharp pain and hyperesthesia disappeared completely, but the constant burning pain persisted although it was less intense. At an 8-month follow-up examination, the patient showed a progressive improvement of clinical symptoms and control magnetic resonance imaging (MRI) showed the complete removal of the neoplasm and the absence of residuals or recurrences.

CONCLUSION

Although in a high percentage of cases of atypical trigeminal neuralgia a neurovascular conflict might be suspected, the review of the present case suggests that the hypothesis of a trigeminal neurinoma must be investigated both with adequate neuroradiological procedures and/or microsurgical exploration of the trigeminal root.