Interplay Between Inflammation and Epigenetic Changes in Cancer.

Immune responses can suppress tumorigenesis, but also contribute to cancer initiation and progression suggesting a complex interaction between the immune system and cancer. Epigenetic alterations, which are heritable changes in gene expression without changes to the DNA sequence, also play a role in carcinogenesis through silencing expression of tumor suppressor genes and activating oncogenic signaling. Interestingly, epithelial cells at sites of chronic inflammation undergo DNA methylation alterations that are similar to those present in cancer cells, suggesting that inflammation may initiate cancer-specific epigenetic changes in epithelial cells. Furthermore, epigenetic changes occur during immune cell differentiation and participate in regulating the immune response, including the regulation of inflammatory cytokines. Cancer cells utilize epigenetic silencing of immune-related genes to evade the immune response. This chapter will detail the interactions between inflammation and epigenetics in tumor initiation, promotion, and immune evasion and how these connections are being leveraged in cancer prevention and treatment.

Combined HIV prevention, the New York City condom distribution program, and the evolution of safer sex behavior among persons who inject drugs in New York City.

Examine long term sexual risk behaviors among persons who inject drugs (PWID) in New York City following implementation of "combined" prevention programming, including condom social marketing. Quantitative interviews and human immunodeficiency virus (HIV) testing were conducted among PWID entering Beth Israel Medical Center drug treatment programs 1990-2012. Data were analyzed by four time periods corresponding to the cumulative implementation of HIV prevention interventions. 7,132 subjects were recruited from 1990 to 2012; little change in sexual behavior occurred among HIV seronegative subjects, while HIV seropositive subjects reported significant decreases in being sexually active and significant increases in consistent condom use. HIV transmission risk (being HIV positive and engaging in unprotected sex) declined from 14 % in 1990-1995 to 2 % in 2007-2012 for primary sexual partners and from 6 to 1 % for casual partners. Cumulative implementation of combined prevention programming for PWID was associated with substantial decreases in sexual risk behavior among HIV seropositives.

Factors associated with recent HIV testing among men who have sex with men in New York City.

Understanding factors associated with recent HIV testing among men who have sex with men (MSM) is important for designing interventions to increase testing rates and link cases to care. A cross-sectional study of MSM was conducted in NYC in 2011 using venue-based sampling. Associations between HIV testing in the past 12 months and relevant variables were examined through the estimation of prevalence ratios (PR) and 95 % confidence intervals (CI). Of 448 participants, 107 (23.9 %) had not been tested in the past 12 months. Factors independently associated with not testing in the previous 12 months were: lack of a visit to a healthcare provider in the past 12 months (aPR: 2.5; 95 % CI: 1.9, 3.2); age ≥30 (adjusted PR: 1.9; 95 % CI: 1.4, 2.7); not having completed a bachelor's degree (aPR: 1.6; 95 % CI: 1.0, 2.4); and non-gay sexual identity (aPR: 1.4; 95 % CI: 1.0, 1.8); such MSM may be less aware of the need for frequent HIV testing.

30 Years on Selected Issues in the Prevention of HIV among Persons Who Inject Drugs.

After 30 years of extensive research on human immunodeficiency virus (HIV) among persons who inject drugs (PWID), we now have a good understanding of the critical issues involved. Following the discovery of HIV in 1981, epidemics among PWID were noted in many countries, and consensus recommendations for interventions for reducing injection related HIV transmission have been developed. While high-income countries have continued to develop and implement new Harm Reduction programs, most low-/middle-income countries have implemented Harm Reduction at very low levels. Modeling of combined prevention programming including needle exchange (NSP) and antiretroviral therapy (ARV) suggests that NSP be given the highest priority. Future HIV prevention programming should continue to provide Harm Reduction programs for PWID coupled with interventions aimed at reducing sexual transmission. As HIV continues to spread in low- and middle-income countries, it is important to achieve and maintain high coverage of Harm Reduction programs in these locations. As PWID almost always experience multiple health problems, it will be important to address these multiple problems within a comprehensive approach grounded in a human rights perspective.

Herpes simplex virus type 2 associated with HIV infection among New York heterosexuals living in high-risk areas.

Herpes simplex virus type 2 (HSV-2) has been shown to increase the risk of sexual human immunodeficiency virus (HIV) transmission. A matched case-control design was used to examine the association between HSV-2 and HIV infection among heterosexuals in 'high-risk areas' (HRAs) in New York City (NYC). We identified NYC HRAs using HIV surveillance data on heterosexual-related adult HIV diagnoses and USA census data on household poverty. Heterosexuals who were socially or geographically linked to an HRA were recruited using respondent-driven sampling. HIV prevalence was 8.6% and HSV-2 prevalence was 80.1%. Only 6% of HIV-positives knew they were infected. HIV-positive cases were matched to HIV-negative controls on gender, race/ethnicity and age, and tested for antibody to HSV-2. In a multivariate model, HIV infection was associated with HSV-2 infection (adjusted odds ratio [AOR] = 3.5, 95% confidence interval 1.1-11.7) and non-HSV-related sexually transmitted infection diagnosis in the previous year (AOR = 2.6, 1.1-6.2). Effective approaches to HIV risk reduction for individuals with HSV-2 remain uncertain, and these are urgently needed in high-risk communities where multiple social, behavioural and biological factors that facilitate HIV infection coexist.

Evaluation of a patient referral contact tracing programme for hepatitis B and C virus infection in drug injectors.

Effective contact tracing for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection could enhance disease control, especially in populations with low HBV vaccination rates and high prevalence of untreated HCV infection. We evaluated a low-cost approach to HBV/HCV contact tracing in injection drug users (IDUs). Index cases (n=26) were IDUs who seroconverted to HBV and/or HCV during a prospective cohort study in Seattle. Interviewers elicited index cases' recent injection partners and administered recall cues and other techniques to boost recall. Index cases received vouchers for free hepatitis testing, which they were to give to locatable partners. Persons redeeming vouchers also received small monetary incentives. Most (26/40) seroconverters participated in the paid contact interviews. Index cases reported many partners (mean=17), and in the aggregate, index cases indicated they could refer more than one third of their elicited partners for testing. Overall, only 17 persons were ultimately referred and just eight of these were confirmed as partners sought for referral. The supplementary elicitation techniques, and especially the recall cues, increased reporting of injection partners substantially. The injection network constructed from reported partnerships was mostly connected and cyclic. Successful contact tracing in IDUs likely requires active involvement by public health staff to locate and notify exposed injection partners.

Needle exchange use, sexual risk behaviour, and the prevalence of HIV, hepatitis B virus, and hepatitis C virus infections among Bulgarian injection drug users.

At a time when the rates of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) infections have risen among injection drug users (IDUs) in other countries in the region, little is known about the prevalence of these infections among Bulgarian injectors and about their sexual risk behaviours. IDUs (n = 773) in a community-based needle exchange programme (NEP) and two major drug treatment facilities in Sofia completed a structured interview and were tested for HIV, HBV, and HCV antibodies. While HCV prevalence in the sample was 73.9%, HBV and HIV prevalence was low -6% and 0.5%, respectively. Having more than 10 sexual partners, having sex with someone with hepatitis C or another IDU, and never using a condom with another IDU were common among those who were recruited through NEP. As 40% of the IDUs reported using NEP, it appears that needle exchange provides an opportunity to reach high-risk populations and prevent sexual transmission of blood-borne pathogens.

Factors associated with interest in initiating treatment for hepatitis C Virus (HCV) infection among young HCV-infected injection drug users.

OBJECTIVE: We sought to identify factors associated with interest in receiving therapy for hepatitis C virus (HCV) infection among HCV-infected injection drug users (IDUs) in 3 United States cities. METHODS: IDUs aged 18-35 years who were HCV-infected and seronegative for human immunodeficiency virus underwent surveys on behaviors, experience, and interest in treatment for HCV infection and readiness to quit drug use. RESULTS: Among treatment-naive IDUs (n=216), 81.5% were interested in treatment for HCV infection, but only 27.3% had seen a health-care provider since receiving a diagnosis of HCV infection. Interest in treatment for HCV infection was greater among IDUs with a high perceived threat of progressive liver disease, those with a usual source of care, those without evidence of alcohol dependence, and those with higher readiness scores for quitting drug use. Interest in treatment for HCV infection was 7-fold higher among IDUs who were told by their health-care provider that they were at risk for cirrhosis or liver cancer. CONCLUSIONS: Improving provider-patient communication and integrating treatments for substance abuse and HCV may increase the proportion of IDUs who initiate treatment for HCV infection.

Advocacy for women's health should include lesbian health.

Although research confirms that homosexuality is a normal expression of human sexuality, established scientific studies are often not reflected in laws and judicial opinions for lesbians with regard to employment, taxation, pensions, disability, healthcare, immigration, military service, marriage, custody, and adoption. The expression of homosexual attraction or behavior is sometimes met by disdain or violence. Psychological and epidemiological research confirms that the public discriminatory attitudes and second-class legal status cause physical, emotional, and financial harm to lesbians, their families, and their children. Some lesbians experience discrimination in healthcare and avoid routine primary healthcare. To decrease the harm, and improve the health of lesbians, medical institutions can include sexual orientation and gender identity in their nondiscrimination policies and offer domestic partner coverage in employment benefits. Our specialty societies should review current laws and judicial opinions and advocate for change. Further, specialty societies can effect change by issuing policy statements about issues of orientation and by writing orientation/identity curricula for public schools, colleges, and postcollegiate education to improve their accuracy, reduce sexually transmitted diseases, delay sexual activity, and reduce morbidity from homophobic violence.

Induction of ser15 and lys382 modifications of p53 by blockage of transcription elongation.

Blockage of transcription has been shown to induce the tumor suppressor p53 in human cells. We here show that RNA synthesis inhibitors blocking the phosphorylation of the carboxyl terminal domain (CTD) of RNA polymerase II, such as DRB and H7, induced rapid nuclear accumulation of p53 proteins that were not phosphorylated at ser15 or acetylated at lys382. In contrast, agents that inhibit the elongation phase of transcription, such as UV light, camptothecin or actinomycin D, induced the accumulation of nuclear p53 proteins that were modified at both of these sites. Furthermore, using a panel of DNA repair-deficient cells we show that persistent DNA lesions in the transcribed strand of active genes are responsible for the induction of the ser15 and lys382 modifications following UV-irradiation. We conclude that inhibition of transcription is sufficient for the accumulation of p53 in the nucleus regardless of whether the ser15 site of p53 is phosphorylated or not. Importantly, blockage of the elongation phase of transcription triggers a distinct signaling pathway leading to p53 modifications on ser15 and lys382. We propose that the elongating RNA polymerase complex may act as a sensor of DNA damage and as an integrator of cellular stress signals.

Functional analysis of the yeast Ran exchange factor Prp20p: in vivo evidence for the RanGTP gradient model.

Numerous cellular processes rely on the movement of macromolecules into and out of the nucleus. The primary regulator of this movement is the small GTPase Ran. Like other small GTPases, the nucleotide-bound state of Ran is regulated by effectors that enhance the rate of nucleotide exchange or hydrolysis. Current models for vectorial nuclear transport suggest that it is the strict compartmentalization of these Ran effector molecules that generates a gradient of RanGTP between the nucleus and the cytoplasm to impart directionality to the transport process. Here we investigate the mechanism by which the Ran exchange factor is targeted to the nucleus, and test the impact of disrupting this nuclear compartmentalization on nucleocytoplasmic transport in vivo. Our results indicate that in Saccharomycces cerevisiae the nucleotide exchange factor Prp20p can be targeted to the nucleus via a classical nuclear localization sequence. This transport mechanism is dependent both on Ran and the receptor that recognizes the nuclear localization sequence, importin alpha. Mutations in the evolutionarily conserved nuclear localization sequence only partially inhibit nuclear import of Prp20p, suggesting the existence of a secondary mechanism for this critical nuclear targeting. In an in vivo test of the RanGTP gradient model, we demonstrate that overexpression of a functional cytoplasmic exchange factor inhibits cell growth and blocks both protein import and RNA export in wild-type cells that contain the endogenous nuclear Prp20 protein. Taken together, our results provide in vivo evidence for the idea that the compartmentalization of the exchange factor serves as a mechanism for establishing directional nuclear transport.

Hepatitis B virus genotypes and HBsAg subtypes in refugees and injection drug users in the United States determined by LiPA and monoclonal EIA.

Hepatitis B virus (HBV) genotyping and hepatitis B surface antigen (HBsAg) subtyping were carried out on sera from 196 HBsAg-positive patients, including 151 refugees entering the United States and 45 injection drug users in Seattle. HBsAg subtyping was performed by enzyme immunoassay (EIA) using a panel of monoclonal antibodies and the HBV genotype was determined by polymerase chain reaction (PCR) followed by detection of amplified HBV DNA by a reverse-phase hybridization line probe assay (LiPA) using genotype-specific probes. HBV DNA was detected by PCR in 155 (79%) of the 196 sera and all 155 were genotyped by LiPA. Samples from Southeast Asia were predominantly genotype B/subtype ayw1 and genotype C/adr; samples from the former Soviet Union and eastern Europe were mostly genotype D/ayw2 and genotype D/ayw3; samples from east Africa were mainly genotype A/adw2 and genotype D/ayw2; and samples from injection drug users were mostly genotype D/ayw3 and genotype A/adw2. Some strains of ayw3 gave atypical monoclonal antibody reactivity patterns in the subtyping assay due to a Val/Ala instead of a Thr at amino acid residue 118 and a Thr instead of a Met at residue 125. A strain of ayw2 also gave an atypical monoclonal antibody reactivity pattern due to an Ala instead of a Thr at amino acid residue 123. LiPA genotyping and monoclonal EIA subtyping can provide useful information for epidemiological studies.

Predictors of accidental fatal drug overdose among a cohort of injection drug users.

OBJECTIVES: This study evaluated factors associated with accidental fatal drug overdose among a cohort of injection drug users (IDUs). METHODS: In a prospective cohort study of 2849 IDUs in King County, Washington, deaths were identified by electronically merging subject identifiers with death certificate records. Univariate and multivariate Cox regression analyses were performed to identify predictors of overdose mortality. RESULTS: Thirty-two overdoses were observed. Independent predictors of overdose mortality were bisexual sexual orientation (relative risk [RR] = 4.86; 95% confidence interval [CI] = 2.30, 13.2), homelessness (RR = 2.30; 95% CI = 1.06, 5.01), infrequent injection of speedballs (RR = 5.36; 95% CI = 1.58, 18.1), daily use of powdered cocaine (RR = 4.84; 95% CI = 1.13, 20.8), and daily use of poppers (RR = 22.0; 95% CI = 1.74, 278). CONCLUSIONS: Sexual orientation, homelessness, and drug use identify IDUs who may benefit from targeted interventions.

Using a jail-based survey to monitor HIV and risk behaviors among Seattle area injection drug users.

Routine monitoring of human immunodeficiency virus (HIV) and risk behaviors among injection drug users (IDUs) is difficult outside drug treatment settings. We developed and implemented a survey of recently arrested IDUs to describe the prevalence of HIV, drug use, and sexual behaviors among them. A probability sampling survey was instituted in the King County Correctional Facility in Seattle, Washington, to sample recently arrested IDUs at the time of booking and in the jail health clinic between 1998 and 1999. Following HIV risk assessment and blood draw, additional information on drug use practices was gathered using a standardized questionnaire. Potential participants who were released from jail early could complete the study at a nearby research storefront office. Of the 4,344 persons intercepted at booking, 503 (12%) reported injection drug use, and 201 of the IDUs (40%) participated in the study. An additional 161 IDUs were enrolled in the study from the jail health clinic. Among the 348 unduplicated subjects, HIV prevalence was 2%; in the past 6 months, 69% reported two or more shooting partners, 72% used a cooker after someone else, 60% shared a syringe to divide up drugs, and 62% injected with used needles. Only 37% reported being hepatitis C seropositive, and 8% reported hepatitis B vaccination. It was feasible to conduct a jail-based survey of recently arrested IDUs that yielded useful information. The high prevalence of reported risky drug use practices warrants ongoing monitoring and illustrates the need for improving prevention programs for HIV and hepatitis B and C in this population, including expansion of hepatitis C screening and provision of hepatitis B vaccination at the jail health clinic.

Accumulation of soluble and nucleolar-associated p53 proteins following cellular stress.

The tumor suppressor p53 is a nucleocytoplasmic shuttling protein that accumulates in the nucleus of cells exposed to various cellular stresses. One important role of nuclear p53 is to mobilize a stress response by transactivating target genes such as the p21(Waf1) gene. In this study, we investigated more closely the localization of p53 in cells following various stresses. Immunocytochemistry of fixed human fibroblasts treated with either UV light, the kinase and transcription inhibitor DRB or the proteasome inhibitor MG132 revealed abundant p53 localized to the nucleus. When cells treated with UV or DRB were permeabilized prior to fixation to allow soluble proteins to diffuse, the nuclear p53 signal was abolished. However, in cells treated with MG132, residual p53 localized to distinct large foci. Furthermore, nucleolin co-localized with p53 to these foci, suggesting that these foci were nucleolar structures. Interestingly, the MDM2 protein was found to co-localize with p53 to nucleolar structures following proteasome inhibition. Our results suggest that the p53 proteins accumulating in the nucleus following UV-irradiation or blockage of transcription are freely soluble and, thus, should be able to roam the nucleus to ensure high occupancy of p53 binding sites. However, inhibition of proteasome activity may be a unique stress in that it leads to the sequestering of p53 proteins to the nucleolus, thereby blunting the p53-mediated transactivation of target genes.

Sharing of drug preparation equipment as a risk factor for hepatitis C.

OBJECTIVES: This study investigated the sharing of drug preparation equipment as a possible route of hepatitis C virus (HCV) transmission. METHODS: HCV seroconversion was measured in a cohort of 317 injection drug users who tested negative for HCV antibody at recruitment. RESULTS: Cumulative HCV incidence was 16.7% per year. Among those who did not share syringes, HCV seroconversion was associated with sharing drug cookers and filtration cotton (adjusted risk ratio = 5.9; 95% confidence interval = 1.1, 31.7); 54% of HCV infections in injection drug users who did not share syringes were attributable to cooker/cotton sharing. CONCLUSIONS: Among injection drug users who do not share syringes, an important proportion of HCV infections may be attributed to cooker/cotton sharing.

HIV and HCV infection among injecting drug users.

BACKGROUND: Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are the two blood-borne pathogens most commonly transmitted among injection drug users via multi-person use of syringes and other injection equipment. However, important differences exist in the epidemiology of HIV and HCV within different populations of intravenous drug users. METHOD: A literature review was carried out to summarize publications describing the epidemiology and natural history of HIV and HCV in injection drug users. RESULTS: Among injection drug users worldwide, HIV prevalence varies from <5% to >80%, with annual HIV incidence between <1% and 50%. More consistency is shown in HCV prevalence (50-90%) and incidence (10-30% per year). Host, environmental and viral factors that favor rapid spread of HCV among IDUs suggest that HCV infection in a population of injection drug users may become endemic over a relatively short period of time. Lower transmission efficiency for HIV also indicates that its spread among injection drug users may be somewhat slower. CONCLUSIONS: Successful efforts to prevent transmission of blood-borne viruses among IDUs typically result in risk reduction; however, no intervention has resulted in elimination of risk behavior. To reduce HIV transmission, risk reduction may be sufficient, whereas control of HCV may necessitate the use of injection practices that guarantee elimination of exposure to equipment contaminated with even small amounts of blood.

Reduced injection frequency and increased entry and retention in drug treatment associated with needle-exchange participation in Seattle drug injectors.

The association between needle exchange, change in drug use frequency and enrollment and retention in methadone drug treatment was studied in a cohort of Seattle injection drug users (IDUs). Participants included IDUs classified according to whether they had used a needle exchange by study enrollment and during the 12-month follow-up period. The relative risk (RR) and the adjusted RR (ARR) were estimated as measures of the association. It was found that IDUs who had formerly been exchange users were more likely than never-exchangers to report a substantial (> or= 75%) reduction in injection (ARR = 2.85, 95% confidence limit [CL] 1.47-5.51), to stop injecting altogether (ARR = 3.5, 95% CL 2.1-5.9), and to remain in drug treatment. New users of the exchange were five times more likely to enter drug treatment than never-exchangers. We conclude that reduced drug use and increased drug treatment enrollment associated with needle exchange participation may have many public health benefits, including prevention of blood-borne viral transmission.

Methadone treatment and HIV and hepatitis B and C risk reduction among injectors in the Seattle area.

Drug treatment has the potential to reduce incidence of blood-borne infections by helping injection drug users (IDUs) achieve abstinence or by decreasing the frequency of injection and sharing practices. We studied the associations between retention in methadone treatment and drug use behaviors and incidence of hepatitis B and C in a cohort of IDUs in the Seattle, Washington, area. Data on IDUs entering methadone treatment at four centers in King County, Washington, were collected through face-to-face interviews using a standardized questionnaire at baseline and 12-month follow-up between October 1994 and January 1998. Blood specimens were obtained and tested for human immunodeficiency virus (HIV) and hepatitis B and C. Drug treatment status at follow-up was analyzed in relation to study enrollment characteristics and potential treatment outcomes, including injection risk behaviors, cessation or reduced frequency of injection, and incidence of hepatitis B and C. Of 716 IDUs, 292 (41%) left treatment, 198 (28%) disrupted (left and returned) treatment, and 226 (32%) continued treatment throughout the 1-year follow-up period. Compared to those who left treatment, subjects who disrupted or continued were less likely to inject at follow-up (odds ratio [OR] = 0.5, 95% CI 0.3-0.7; and OR = 0.1, 95% CI 0.1-0.2, respectively). Among the 468 (65%) subjects who continued injecting, those who continued treatment injected less frequently, were less likely to pool money to buy drugs (OR = 0.5, 95% CI 0.3-0.8) and inject with used needles (OR = 0.5, 95% CI 0.2-0.8) compared to those who left treatment. Cooker or cotton sharing was not associated with retention in treatment, but hepatitis B incidence was lowest among those who continued treatment. The results of this study suggest drug use risk reduction is more likely to be achieved by those who remain in drug treatment and by those who stop injecting, but that those who drop out and return and those who continue to inject while in treatment may also benefit. This supports the role of consistent drug treatment in an overall harm-reduction strategy.