Maria Da Costa

Anal intraepithelial neoplasia in the highly active antiretroviral therapy era among HIV-positive men who have sex with men.

Objectives:The incidence of anal cancer among men who have sex with men (MSM) has continued to increase since the introduction of highly active antiretroviral therapy (HAART). The prevalence of the putative anal cancer precursor, anal intraepithelial neoplasia (AIN) was high among HIV-positive MSM prior to the availability of HAART but little is known about AIN since HAART was introduced. We characterized the prevalence of AIN among HIV-positive MSM and examined the association between AIN and various factors including use of HAART. Design and methods:A baseline point-prevalence analyses in a prospective cohort study of AIN was performed at a university-based research clinic. A total of 357 HIV-positive MSM with no history of anal cancer completed a questionnaire detailing behaviors and medical history, anal cytology and human papillomavirus (HPV) testing, and high-resolution anoscopy with biopsy for detection of AIN. Results:Eighty-one percent of participants with available CD4+ cell counts at baseline had AIN of any grade; 52% had AIN 2 or 3; and 95% had anal HPV infection. In multivariate analysis, detection of ≥ 6 HPV types [odds ratio (OR), 36; 95% confidence interval (CI), 7.4–171) and use of HAART (OR, 10; 95% CI, 2.6–38) were associated with AIN after adjustment for length of time participants were HIV-positive, CD4+ cell count and HIV viral load. Conclusions:The prevalence of AIN has remained high among HIV-positive MSM after the introduction of HAART. Our data indicate that HAART is not associated with a reduced prevalence of AIN and support measures to prevent anal cancer among HIV-positive MSM whether or not they are using HAART.

Genetic dissection of the oncogenic mTOR pathway reveals druggable addiction to translational control via 4EBP-eIF4E.

We genetically dissect the contribution of the most prominent downstream translational components of mTOR signaling toward Akt-driven lymphomagenesis. While phosphorylation of rpS6 is dispensable for cancer formation, 4EBP-eIF4E exerts significant control over cap-dependent translation, cell growth, cancer initiation, and progression. This effect is mediated at least in part through 4EBP-dependent control of Mcl-1 expression, a key antiapoptotic protein. By using an active site inhibitor of mTOR, PP242, we show a marked therapeutic response in rapamycin-resistant tumors. The therapeutic benefit of PP242 is mediated through inhibition of mTORC1-dependent 4EBP-eIF4E hyperactivation. Thus, the 4EBP-eIF4E axis downstream of mTOR is a druggable mediator of translational control and Akt-mediated tumorigenesis that has important implications for the treatment of human cancers.

High Prevalence of Anal Human Papillomavirus Infection and Anal Cancer Precursors among HIV-Infected Persons in the Absence of Anal Intercourse

Context Anal cancer is associated with human papillomavirus (HPV) infection and receptive anal intercourse and is more common in HIV-positive than HIV-negative homosexual men. Little is known about HPV infection and anal lesions in HIV-positive men with no history of receptive anal intercourse. Contribution In this cross-sectional study of HIV-positive men, 46% of 50 heterosexual men who reported no history of receptive anal intercourse had anal HPV infection and 36% had anal squamous intraepithelial lesions. Low CD4+ cell counts were associated with an increased risk for anal lesions. Implications Anal HPV infection and precancerous lesions occur without receptive anal intercourse in HIV-positive men. The Editors The incidence of anal cancer among men with a history of receptive anal intercourse before the HIV epidemic was several times higher than the current rate of cervical cancer in women in the United States; the incidence of anal cancer is estimated to be as high as 35 per 100 000 in this population (1, 2). Anal cancer is associated with human papillomavirus (HPV) infection (3, 4). Earlier studies of the risk for anal cancer in HIV-negative populations showed that a history of receptive anal intercourse was an important risk factor (2, 5), presumably because it increased the risk for acquiring anal HPV infection. Both anal squamous intraepithelial lesions (SILs) and anal HPV infection are more common in HIV-positive than in HIV-negative men who have sex with men (6-13). Recent studies estimated that the incidence of anal cancer was twofold higher in HIV-infected than in HIV-negative men who had sex with men (14, 15); in addition, the relative risk for developing anal cancer among HIV-positive men was 37-fold higher than in the general population (16). Human immunodeficiency virus-positive men who had sex with men were at 60-fold higher risk. Human immunodeficiency virus-positive injection drug users were also at increased risk (6-fold), although less so than the HIV-positive men who had sex with men. In HIV-positive men who have sex with men, it is difficult to ascertain the role of anal intercourse as a risk factor for anal HPV infection or anal SIL, given the high prevalence of this behavior in this population. Immunosuppression probably plays a role, as indicated in studies showing an association between anal SIL and low CD4+ cell counts (6, 10, 13). In addition, evidence shows that the risk for anal SIL is increased in renal allograft recipients in the absence of receptive anal intercourse (17-19). Cervical cytologic screening to detect cervical high-grade SIL (HSIL) followed by treatment of the lesions substantially reduces the incidence of cervical cancer. Studies of anal cytologic screening to determine whether the incidence of anal cancer can similarly be reduced have not yet been done. However, according to costbenefit modeling over a wide range of assumptions, anal cytologic screening in HIV-positive men who have sex with men has been projected to be cost-effective for preventing anal cancer (20, 21). In this cross-sectional study, we compared the prevalence of and risk factors for abnormal anal histologic or cytologic findings in HIV-positive men who have sex with men with male HIV-positive injection drug users who reported no history of anal intercourse. This was done to assess the role of HIV-related immunodeficiency in detecting anal HPV infection and anal disease in the absence of anal intercourse. In addition, we sought to determine whether the prevalence of anal HPV infection and anal SIL was high enough in HIV-positive injection drug users to warrant additional studies of potential benefit from anal cytologic screening in this population. Methods Study Design Between June 1999 and October 2000, 120 HIV-seropositive men attending the outpatient clinic of Hpital Europen Georges Pompidou, Paris, France, were recruited in a cross-sectional study of anal HPV infection and anal SIL in HIV-seropositive men. Men were eligible for the study if they had acquired HIV through homosexual or bisexual contact or through injection drug use, were older than 18 years of age, and had absolute CD4+ cell counts less than 500 106 cells/L. Injection drug users who had sex with men were excluded from the study. The patients were recruited from a cohort of 1198 HIV-infected patients who were followed at the Clinical Immunology unit of Hpital Europen Georges Pompidou. All patients were consecutively enrolled into the study. No eligible patient declined participation. The Ethics Review Board of Hpital Piti-Salpetrire, Paris, and the Committee on Human Research of the University of California, San Francisco, approved the protocol and written informed consent documents. Patients provided signed written consent before inclusion in the study. All men were interviewed by using a standardized, comprehensive, self-administered questionnaire that included questions on age, education status, professional activity, tobacco use, route of HIV infection, medical history, history of sexually transmitted diseases, history of HPV-related disease, history of treatment for anal disease, drug use, age at first intercourse, total number of sexual partners, total number of receptive and insertive anal intercourse, and history of commercial sex work with men. The questionnaire was a French translation of a questionnaire used in other published studies conducted at the University of California, San Francisco (10). The questionnaires were self-administered, and the investigators were blinded to the results to better ensure patient privacy and accuracy of the data. Cytologic and Histologic Analyses Patients had a thorough anal examination that included insertion of a Dacron swab (Eurotubo, Rubi, Spain) for anal cytologic and HPV testing. The swab was immediately rinsed in a vial of PreservCyt fixative fluid (Cytyc Corp., Boxborough, Massachusetts). Each vial was used for HPV testing and ThinPrep cytologic screening (Cytyc Corp.). An aliquot was taken from the vial for HPV testing; slides were then prepared from the vial by using the ThinPrep 2000 processor (Cytyc Corp.). When cytologic abnormalities were found, consenting patients underwent anoscopic examination and biopsy with the use of a colposcope (22). Biopsy specimens were fixed in 10% formalin for routine histopathologic examination. Anal cytologic and histologic results were evaluated independently of each other, without knowledge of clinical status and HIV risk group of the patient or HPV results. Anal cytologic results were classified as normal, atypical squamous cell of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), or HSIL by using the Bethesda system criteria for evaluation of cervical cytologic results. If both cytologic and histologic results were available for analysis, a patients diagnosis was categorized as the more severe result. Detection of Anal HPV DNA Polymerase chain reaction (PCR) for anal HPV DNA detection was performed in a blinded fashion. To determine specimen adequacy, genomic DNA was isolated from the ThinPrep vial and amplified by using MY09/MY11 consensus HPV L1 primers as well as primers to amplify the human -globin gene (9). After 40 amplification cycles, specimens were probed with a biotin-labeled HPV L1 consensus probe mixture. A separate membrane was probed with biotin-labeled probes for the human -globin gene. We performed type-specific probing for the following HPV types individually: 6; 11; 16; 18; 26; 31; 32; 33; 35; 39; 40; 45; 51; 52; 53; 54; 55; 56; 58; 59; 61; 66; 68; 69; 70; 73; Pap 155; Pap 291; AE2; and a mix containing 2, 13, 34, 42, 57, 62, 64, 67, 72, and W13B. We designated samples that were positive with the consensus probes but negative with the individual type-specific probes as having one or more other types. Polymerase chain reaction can be used to discriminate between low-level HPV infection and high-level HPV infection on the basis of intensity of the PCR signal on Southern blot analysis (23), which was recorded on a scale from 0 (negative) to 5. For the purpose of the analysis, a sample that was positive for more than one HPV high-risk types was categorized as the higher PCR signal from the sample. CD4+ Cell Count and Plasma HIV RNA Viral Load We used the CD4+ cell counts and plasma HIV RNA viral loads closest to the period within 2 months of the anal examination. The nadir CD4+ cell count was defined as the lowest count recorded before the study. Absolute numbers of CD4+ T cells were determined by standard flow cytometry. Plasma HIV RNA levels were determined by the branched-chain DNA signal amplification assay (Quantiplex HIV-RNA, Chiron Diagnostics Corp., Emeryville, California). Statistical Analysis We analyzed data by using StatView 5 software (SAS Institute, Inc., Cary, North Carolina). Because most variables had skewed distribution, data are presented as median and ranges. Differences across HIV risk groups were tested with the Fisher exact test (categorical variables) and the nonparametric Mann-Whitney U test (continuous variables). Patients with HPV infection and histologic or cytologic abnormalities were compared with patients with no evidence of HPV infection or anal disease. To identify risk factors for histologic or cytologic abnormalities, the following dichotomous variables were entered into a logistic regression model: age (<35 vs. 35 years), age at first intercourse (<16 vs. 16 years), number of lifetime sexual partners (<40 vs. 40), number of receptive anal intercourse episodes (<10 vs. 10), current smoking, history of anogenital warts, history of sexually transmitted disease (including anogenital herpes, gonorrhea, and syphilis), CD4+ cell count less than 250 106 cells/L, nadir CD4+ cell count less than 100 106 cells/L, plasma HIV RNA viral load greater than 1.7 log copies/mL, previous AIDS-defining event, current antiretroviral treatment, current protease inhibitor tr

Suppression of Myc oncogenic activity by ribosomal protein haploinsufficiency

The Myc oncogene regulates the expression of several components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, RNA polymerase III and ribosomal DNA. Whether and how increasing the cellular protein synthesis capacity affects the multistep process leading to cancer remains to be addressed. Here we use ribosomal protein heterozygote mice as a genetic tool to restore increased protein synthesis in Eμ-Myc/+ transgenic mice to normal levels, and show that the oncogenic potential of Myc in this context is suppressed. Our findings demonstrate that the ability of Myc to increase protein synthesis directly augments cell size and is sufficient to accelerate cell cycle progression independently of known cell cycle targets transcriptionally regulated by Myc. In addition, when protein synthesis is restored to normal levels, Myc-overexpressing precancerous cells are more efficiently eliminated by programmed cell death. Our findings reveal a new mechanism that links increases in general protein synthesis rates downstream of an oncogenic signal to a specific molecular impairment in the modality of translation initiation used to regulate the expression of selective messenger RNAs. We show that an aberrant increase in cap-dependent translation downstream of Myc hyperactivation specifically impairs the translational switch to internal ribosomal entry site (IRES)-dependent translation that is required for accurate mitotic progression. Failure of this translational switch results in reduced mitotic-specific expression of the endogenous IRES-dependent form of Cdk11 (also known as Cdc2l and PITSLRE), which leads to cytokinesis defects and is associated with increased centrosome numbers and genome instability in Eμ-Myc/+ mice. When accurate translational control is re-established in Eμ-Myc/+ mice, genome instability is suppressed. Our findings demonstrate how perturbations in translational control provide a highly specific outcome for gene expression, genome stability and cancer initiation that have important implications for understanding the molecular mechanism of cancer formation at the post-genomic level.

Prevalence and Risk Factors for Anal Human Papillomavirus Infection in Human Immunodeficiency Virus (HIV)—Positive and High-Risk HIV-Negative Women

Little is known about the epidemiology of anal human papillomavirus (HPV) infection in women. We studied 251 human immunodeficiency virus (HIV)-positive and 68 HIV-negative women for the presence of anal HPV by use of polymerase chain reaction (PCR) and hybrid capture. Medical and behavioral risk factors were evaluated; 76% of HIV-positive and 42% of HIV-negative women were found to have anal HPV DNA via analysis by PCR (relative risk [RR], 1.8; 95% confidence interval [CI], 1.3-2.5). Among 200 women for whom there were concurrent anal and cervical HPV data, anal HPV was more common than cervical HPV in both HIV-positive (79% vs. 53%) and HIV-negative women (43% vs. 24%). By multivariate analysis of HIV-positive women, CD4(+) cell counts </=200 cells/mm(3), compared with counts >500 cells/mm(3) (RR, 1.4; 95% CI, 1.1-1.5), and cervical HPV infection (RR, 1.3; 95% CI, 1.1-1.4) were associated with anal HPV infection. Women >45 years old had reduced risk, compared with women <36 years old (RR, 0.80; 95% CI, 0.50-0.99), as did African American women (RR, 0.86; 95% CI, 0.72-1.0), compared with white women. Anal HPV infection is underrecognized in HIV-positive and high-risk HIV-negative women.

Age-Specific Prevalence of Anal Human Papillomavirus Infection in HIV-Negative Sexually Active Men Who Have Sex with Men: The EXPLORE Study

BACKGROUND In the United States, anal cancer in men who have sex with men (MSM) is more common than cervical cancer in women. Human papillomavirus (HPV) is causally linked to the development of anal and cervical cancer. In women, cervical HPV infection peaks early and decreases after the age of 30. Little is known about the age-specific prevalence of anal HPV infection in human immunodeficiency virus (HIV)-negative MSM. METHODS We studied the prevalence and determinants of anal HPV infection in 1218 HIV-negative MSM, 18-89 years old, who were recruited from 4 US cities. We assessed anal HPV infection status by polymerase chain reaction. RESULTS HPV DNA was found in the anal canal of 57% of study participants. The prevalence of anal HPV infection did not change with age or geographic location. Anal HPV infection was independently associated with receptive anal intercourse (odds ratio [OR], 2.0; P<.0001) during the preceding 6 months and with >5 sex partners during the preceding 6 months (OR, 1.5; P<.0001). CONCLUSIONS Urban, HIV-negative MSM have a stable, high prevalence of anal HPV infection across all age groups. These results differ substantially from the epidemiologic profile of cervical HPV infection in women. This may reflect differences between these populations with respect to the number of new sex partners after the age of 30 and may explain the high incidence of anal cancer in MSM.

High prevalence of anal squamous intraepithelial lesions in HIV-positive men despite the use of highly active antiretroviral therapy.

Background The impact of highly active antiretroviral therapy (HAART) on the natural history of HPV infection and anal squamous intraepithelial lesions (SIL) in HIV-infected men who have sex with men (MSM) is poorly documented. Goal The goal of this study was to evaluate the prevalence of anal HPV infection and SIL inpatients under HAART. Study Design Forty-five HIV-infected protease inhibitor-experienced MSM were enrolled in a cross-sectional study. Each patient provided anal samples for anal cytology, histology, and human papillomavirus (HPV) DNA testing. Results The patients had previously received HAART for a median of 32 months. Anal cytology was abnormal in 32 of 45 (71%) patients, including high-grade SIL in 10 patients (22%), low-grade SIL in 19 patients (42%), and atypical squamous cells of undetermined significance in 3 patients (7%). HPV DNA was detected 36/45 men (80%). The prevalence of anal SIL and HPV infection were similar in patients exhibiting a significant increase in CD4+ cell count after HAART initiation compared with those who did not. Conclusion Our results demonstrate a high prevalence of anal SIL, including high-grade SIL, and anal HPV infection in HIV-infected MSM despite immune restoration under HAART.

Effect of highly active antiretroviral therapy on the natural history of anal squamous intraepithelial lesions and anal human papillomavirus infection.

&NA; The effect of highly active antiretroviral therapy (HAART) on the natural history of anal squamous intraepithelial lesions (ASIL)‐the likely anal cancer precursor‐and anal human papillomavirus (HPV) infection is unknown. ASIL severity and level of anal HPV DNA were evaluated among HIV‐positive men who have sex with men (MSM) for at least 6 months before initiation of HAART. The results were compared with those from a 6‐month period after initiation of HAART. Anal swabs for cytology and HPV studies were obtained, followed by high‐resolution anoscopy and biopsy. Among men whose most severe pre‐HAART diagnosis was atypical squamous cells of undetermined significance or low‐grade ASIL, 18% (confidence interval [CI], 6‐31%, 7 of 38) progressed and 21% (CI, 8‐34%, 8 of 38) regressed 6 months after starting HAART. Seventeen percent (CI, 0‐38%, 2 of 12) of study subjects who began with a normal diagnosis developed ASIL. Only 4% (CI, 0‐10%, 1 of 28) of study subjects with high‐grade ASIL regressed to normal. There was no reduction in the proportion of study subjects who tested positive for HPV DNA or HPV DNA levels after HAART initiation. The ASIL and HPV data were similar to those of the pre‐HAART comparison period. These results indicate that HAART has little effect on either ASIL or HPV in the first 6 months after HAART initiation.

Anal human papillomavirus infection is associated with HIV acquisition in men who have sex with men

Objective:Human papillomavirus (HPV) is a common sexually transmitted agent that causes anogenital cancer and precancer lesions that have an inflammatory infiltrate, may be friable and bleed. Our aim was to determine the association between anal HPV infection and HIV acquisition. Design:A prospective cohort study. Methods:We recruited 1409 HIV-negative men who have sex with men from a community-based setting in Boston, Denver, New York and San Francisco. We used Cox proportional hazards regression modeling and assessed the independent association of HPV infection with the rate of acquisition of HIV infection. Results:Of 1409 participants contributing 4375 person-years of follow-up, 51 HIV-seroconverted. The median number of HPV types in HPV-infected HIV-seroconverters was 2 (interquartile range 1–3) at the time of HIV seroconversion. After adjustment for sexual activity, substance use, occurrence of other sexually transmitted infections and demographic variables, there was evidence (P = 0.002) for the effect of infection with at least two HPV types (hazard ratio 3.5, 95% confidence interval 1.2–10.6) in HIV seroconversion. Conclusion:Anal HPV infection is independently associated with HIV acquisition. Studies that incorporate high-resolution anoscopy to more accurately identify HPV-associated disease are needed to determine the relationship between HPV-associated disease and HIV seroconversion.

Colorectal Papillomavirus Infection in Patients with Colorectal Cancer

Purpose: Infection with human papillomaviruses (HPV) is associated with the development of cervical cancer, but whether HPVs have a role in colorectal cancer remains controversial. Experimental Designs: To determine the relationship between HPV and colorectal cancer, we did a retrospective, controlled study using tumor and tumor-adjacent colorectal tissues dissected from patients with colorectal cancer, as well as colorectal tissues from control individuals with no cancer. The samples were processed in a blinded fashion for nested PCR and in situ PCR detection of HPV DNAs. The PCR products were gel-purified and sequenced for HPV genotyping. Results: We found that colorectal tissues from 28 of 55 (51%) patients with colorectal cancer were positive for HPV DNA. Colorectal tissues from all 10 control individuals were negative for HPV DNA (P = 0.0034). Of the 107 usable (GAPDH+) samples collected as paired colorectal tissues (tumor and tumor-adjacent tissues) from the patients, 38 (36%) had HPV16 (n = 31), HPV18 (n = 5), or HPV45 (n = 2), with HPV DNA in both tumor and tumor-adjacent tissues of 10 paired samples, 13 in only the tumor, and 5 in only tumor-adjacent tissues. In situ PCR detection of the tumor tissues confirmed the presence of HPV DNA in tumor cells. Conclusion: Our results suggest that colorectal HPV infection is common in patients with colorectal cancer, albeit at a low DNA copy number, with HPV16 being the most prevalent type. HPV infection may play a role in colorectal carcinogenesis.