An RGD containing peptide from HIV-1 Tat-(65-80) modulates protooncogene expression in human bronchoalveolar carcinoma cell line, A549

Potential use of multikinase inhibitors in immunosuppressed patients with malignancies including thyroid cancer

In this article, we focus on a variety of immunosuppression scenarios and whether multikinase inhibitors, as systemic therapy for advanced thyroid carcinoma (TC), could be useful for the treatment of immunocompromised patients with TC. Lenvatinib and sorafenib, among other MKIs, have become the standard of care for advanced TC based on their efficacy data and despite their adverse effects. Currently, published data on MKIs in immunosuppressed patients are scarce. Secondary malignancies can arise in immunosuppressed patients who have undergone solid organ transplantation, human immunodeficiency virus-infected patients, and hematopoietic stem cell transplant recipients. This review will explore different immunosuppression settings, the risk of secondary malignancies in immunosuppressed patients, and the special characteristics of this population. Some considerations regarding anticancer treatment in immunosuppressed patients with advanced malignancies are reviewed.

HIV-related lung cancer in Uganda: a cohort study

Background

There are few reports on lung cancer among people with HIV (PWH) in Sub-Saharan Africa. In this report, we describe a cohort of PWH and lung cancer at the Uganda Cancer Institute.

Methods

This retrospective cohort of PWH and lung cancer was managed at the Uganda Cancer Institute between 2008 and 2018. Sociodemographic and clinical data were abstracted from the patient charts. The median survival from diagnosis to death, loss-to-follow up or 31st December 2018, was estimated.

Results

There were 18 people with HIV and lung cancer. The median (interquartile range, IQR) age was 49.5 (38.8–56.0) years, 11 (61.1%) were women and 5 (27.8%) were smokers. Of the 18 PWH, 13 (72.2%) were on antiretroviral therapy and the median (IQR) CD4 count (n = 13) was 380 (243.5–595) cells per mm³. Difficulty in breathing (88.9%), chest pain (78.6%, n = 11), cough (76.5%, n = 17) and weight loss (72.2%) were the commonest symptoms while pleural effusions were observed in 12 (66.7%). In this cohort, 8 (44.4%) were presumptively treated for tuberculosis before the diagnosis of lung cancer. Seven (38.9%) had an Eastern Cooperative Oncology Group performance status of 3. Non-small cell lung cancer was the predominant histological type observed in 17 (94.4%) of whom 14 (82.4%) had adenocarcinoma. Majority of PWH had stage IV disease (88.9%). The median (IQR) survival was 3.3 (1.1–13.2) months and all were either dead (72.2%) or lost-to-follow up (27.8%) at five years from diagnosis.

Conclusion

People with HIV and lung cancer in Uganda report low rates of smoking, present with advanced disease and post very poor survival rates. There is need for biomarkers for early detection of lung cancer in HIV.

Risk factors of Lung Cancer in nonsmoker

Generally, the cause of lung cancer is attributed to tobacco smoking. But many of the new lung cancer cases have been reported in nonsmokers. Apart from smoking; air pollution, environmental exposure, mutations, and single-nucleotide polymorphisms are known to be associated with lung cancer. Improper diet, alcohol consumption, marijuana smoking, estrogen, infections with human papillomavirus (HPV), HIV, and Epstein-Barr virus are suggested to be linked with lung cancer but clear evidences to ascertain their relation is not available. This article provides a comprehensive review of various risk factors and the underlying molecular mechanisms responsible for increasing the incidence of lung cancer. The pathologic, histologic, and genetic differences exist with lung cancer among smokers and nonsmokers. A better understanding of the risk factors, differences in pathology and molecular features of lung cancer in smokers and nonsmokers and the mode of action of various carcinogens will facilitate the prevention and management of lung cancer.

Mechanisms Underlying HIV-Associated Noninfectious Lung Disease

Pulmonary disease remains a primary source of morbidity and mortality in persons living with HIV (PLWH), although the advent of potent combination antiretroviral therapy has resulted in a shift from predominantly infectious to noninfectious pulmonary complications. PLWH are at high risk for COPD, pulmonary hypertension, and lung cancer even in the era of combination antiretroviral therapy. The underlying mechanisms of this are incompletely understood, but recent research in both human and animal models suggests that oxidative stress, expression of matrix metalloproteinases, and genetic instability may result in lung damage, which predisposes PLWH to these conditions. Some of the factors that drive these processes include tobacco and other substance use, direct HIV infection and expression of specific HIV proteins, inflammation, and shifts in the microbiome toward pathogenic and opportunistic organisms. Further studies are needed to understand the relative importance of these factors to the development of lung disease in PLWH.

HIV-Associated Lung Cancer

Lung cancer (LC) is one of the most common non-AIDS (acquired immune deficiency syndrome)-defining malignancies. It occurs more frequently in persons living with human immunodeficiency virus (PLWHIV) than in the HIV-negative population. Compared to their HIV-negative counterparts, patients are usually younger and diagnosed at more advanced stages. The pathogenesis of LC in PLWHIV is not fully understood, but immunosuppression in combination with chronic infection and the oncogenic effects of smoking and HIV itself all seem to play a role. Currently, no established preventive screening is available, making smoking cessation the most promising preventive measure. Treatment protocols and standards are the same as for the general population. Notably, immuno-oncology will also become standard of care in a significant subset of HIV-infected patients with LC. As drug interactions and hematological toxicity must be taken into account, a multidisciplinary approach should include a physician experienced in the treatment of HIV. Only limited data is available on novel targeted therapies and checkpoint inhibitors in the setting of HIV.

Non-infectious pulmonary disorders in HIV

INTRODUCTION

Since the advent of antiretroviral therapy (ART), non-infectious pulmonary disorders have become common comorbidities in the human immunodeficiency virus (HIV) positive population. Clinicians caring for those with HIV disease should be aware of the prevalence of non-infectious pulmonary disorders. A comprehensive understanding is required to diagnosis and manage these syndromes appropriately. Areas covered: This review focuses on the epidemiology, risk factors, pathogenesis, clinical feature and diagnosis, and treatment of HIV-related chronic obstructive pulmonary disease (COPD), lung cancer, pulmonary hypertension. Expert Commentary: The prevalence of COPD in the HIV population is frequent and requires appropriate diagnosis and treatment. HIV-positive individuals with lung cancer carry a poorer prognosis and require early diagnosis and treatment. A complex condition exists with pulmonary hypertension in the HIV population and requires a high degree of clinical suspicion for early diagnosis.

The evolving scenario of non-AIDS-defining cancers: challenges and opportunities of care

BACKGROUND

The impact of highly active antiretroviral therapies (HAART) on the risk of non-AIDS-defining cancers (NADCs) and the role of biological and clinical factors in their pathogenesis are debated issues. The purpose of this review is to examine the epidemiology, etiology, and not-yet-defined pathogenic characteristics of NADCs and discuss topics such as treatment strategies, comorbidity, and multidrug interactions. Four types of NADCs that deserve special attention are examined: anal cancer, Hodgkin lymphoma (HL), hepatocellular carcinoma, and lung cancer.

METHODS

The PubMed database and the Cochrane Library were searched by focusing on NADCs and on the association among NADCs, HAART, aging, and/or chronic inflammation. All articles were reviewed to identify those reporting variables of interest.

RESULTS

NADC incidence is twofold higher in patients with HIV/AIDS than in the corresponding general population, and this elevated risk persists despite the use of HAART. The mechanisms that HIV may use to promote the development of NADCs are presently unclear; immunological mechanisms, either immunodeficiency and/or immunoactivation, may play a role.

CONCLUSION

Recent clinical studies have suggested that equivalent antineoplastic treatment is feasible and outcome can be similar in HIV-infected patients on HAART compared with uninfected patients for the treatment of HL and anal and lung cancers. However, patients with advanced HIV disease and/or aging-related comorbidities are likely to experience worse outcomes and have poorer tolerance of therapy compared with those with less advanced HIV disease.

Epidemic of lung cancer in patients with HIV infection

The survival of patients with HIV infection has improved dramatically over the past 20 years, largely owing to a significant reduction in opportunistic infections and AIDs-defining malignancies, such as lymphoma and Kaposi sarcoma. However, with improved survival, patients with HIV are experiencing morbidity and mortality from other (non-AIDs-defining) complications, such as solid organ malignancies. Of these, the leading cause of mortality in the HIV-infected population is lung cancer, accounting for nearly 30% of all cancer deaths and 10% of all non-HIV-related deaths. Importantly, the average age of onset of lung cancer in the HIV-infected population is 25 to 30 years earlier than that in the general population and at lower exposure to cigarette smoke. This article provides an overview of the epidemiology of lung cancer in the HIV-infected population and discusses some of the important risk factors and pathways that may enhance the risk of lung cancer in this population.

Updating our understanding of pulmonary disease associated with HIV infection

The introduction of highly active antiretroviral therapy (HAART) has resulted in a reduction of opportunistic infections associated with cellular and humoral immunosuppression. However, what is still unclear is the impact of HAART on the development of other diseases not associated with AIDS, such as lung cancer and COPD. The aim of this paper is to review the most innovative and relevant aspects of lung pathology in patients infected with HIV.

Lung cancer in HIV Infection

Lung cancer is the most prevalent non-AIDS-defining malignancy in the highly active antiretroviral therapy era. Smoking plays a significant role in the development of HIV-associated lung cancer, but the cancer risk is two to four times greater in HIV-infected persons than in the general population, even after adjusting for smoking intensity and duration. Lung cancer is typically diagnosed a decade or more earlier among HIV-infected persons (mean age, 46 years) compared to those without HIV infection. Adenocarcinoma is the most common histological subtype, and the majority of patients are diagnosed with locally advanced or metastatic carcinoma. Because pulmonary infections are common among HIV-infected individuals, clinicians may not suspect lung cancer in this younger patient population. Surgery with curative intent remains the treatment of choice for early-stage disease. Although there is increasing experience in using radiation and chemotherapy for HIV-infected patients who do not have surgical options, there is a need for prospective studies because this population is frequently excluded from participating in cancer trials. Evidence-based treatments for smoking-cessation with demonstrated efficacy in the general population must be routinely incorporated into the care of HIV-positive smokers.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

HIV infection in the etiology of lung cancer: confounding, causality, and consequences

Persons infected with HIV have an elevated risk of lung cancer, but whether the increase simply reflects a higher smoking prevalence continues to be debated. This review summarizes existing data on the association of HIV infection and lung cancer, with particular attention to study design and adjustment for cigarette smoking. Potential mechanisms by which HIV infection may lead to lung cancer are discussed. Finally, irrespective of causality and mechanisms, lung cancer represents an important and growing problem confronting HIV-infected patients and their providers. Substantial efforts are needed to promote smoking cessation and to control lung cancer among HIV-infected populations.

Role of uncontrolled HIV RNA level and immunodeficiency in the occurrence of malignancy in HIV-infected patients during the combination antiretroviral therapy era: Agence Nationale de Recherche sur le Sida (ANRS) CO3 Aquitaine Cohort

BACKGROUND

Human immunodeficiency virus (HIV)-infected patients are at higher risk of malignancies. In addition to traditional determinants, a specific deleterious effect of HIV and immunodeficiency is speculated. We aimed at studying the association between immunological and virological characteristics of HIV-infected patients in care and the risk of acquired immunodeficiency syndrome (AIDS)-defining and non-AIDS-defining malignancies.

METHODS

Patients consecutively enrolled in the hospital-based Agence Nationale de Recherche sur le Sida (ANRS) CO3 Aquitaine Cohort were included if the duration of follow-up was >3 months during the period 1998-2006. Multivariate modeling used an extended Cox proportional hazards model for time-dependent covariates and delayed entry.

RESULTS

The 4194 patients included in the study developed 251 first malignancies during 22,389 person-years. A higher incidence of AIDS-defining malignancies (107 cases) was independently associated with (1) both longer and current exposures to a plasma HIV RNA level >500 copies/mL (hazard ratio [HR], 1.27 per year [P<.001] and 3.30 [P<.001], respectively) and (2) both longer and current exposure to a CD4(+) cell count <200 cells/mm(3) (HR, 1.36 per year [P<.001] and 6.33 [P<.001], respectively). A higher incidence of non-AIDS-defining malignancies (144 cases) was independently associated with longer and current exposure to a CD4(+) cell count <500 cells/mm(3) (HR, 1.13 per year [P=.01] and 2.07 [P<.001], respectively) and male sex (HR, 1.69; P=.02) but not with plasma HIV RNA level (P=.49 and P=.10 for cumulative and current exposures, respectively).

CONCLUSIONS

Uncontrolled plasma HIV RNA level was independently associated with a higher likelihood of developing AIDS-defining malignancies, whereas immunosuppression was associated with a higher risk of developing any type of malignancies. Antiretroviral treatment should aim at reaching and maintaining a CD4(+) count >500 cells/mm(3) to prevent the occurrence of malignancy, this should be integrated to malignancy-prevention policies.

9-Aminoacridine inhibition of HIV-1 Tat dependent transcription

As part of a continued search for more efficient anti-HIV-1 drugs, we are focusing on the possibility that small molecules could efficiently inhibit HIV-1 replication through the restoration of p53 and p21WAF1 functions, which are inactivated by HIV-1 infection. Here we describe the molecular mechanism of 9-aminoacridine (9AA) mediated HIV-1 inhibition. 9AA treatment resulted in inhibition of HIV LTR transcription in a specific manner that was highly dependent on the presence and location of the amino moiety. Importantly, virus replication was found to be inhibited in HIV-1 infected cell lines by 9AA in a dose-dependent manner without inhibiting cellular proliferation or inducing cell death. 9AA inhibited viral replication in both p53 wildtype and p53 mutant cells, indicating that there is another p53 independent factor that was critical for HIV inhibition. p21WAF1 is an ideal candidate as p21WAF1 levels were increased in both p53 wildtype and p53 mutant cells, and p21WAF1 was found to be phosphorylated at S146, an event previously shown to increase its stability. Furthermore, we observed p21WAF1 in complex with cyclin T1 and cdk9 in vitro, suggesting a direct role of p21WAF1 in HIV transcription inhibition. Finally, 9AA treatment resulted in loss of cdk9 from the viral promoter, providing one possible mechanism of transcriptional inhibition. Thus, 9AA treatment was highly efficient at reactivating the p53 – p21WAF1 pathway and consequently inhibiting HIV replication and transcription.

Using peptides to study the interaction between the p53 tetramerization domain and HIV-1 Tat

Peptides are valuable tools for studying protein-protein interactions, especially in cases of isolated protein domains and natively unfolded proteins. Here, we used peptides to quantitatively characterize the interaction between the natively unfolded HIV-1 Tat protein and the tetramerization domain of the cellular tumor suppressor protein p53. We used peptide mapping, fluorescence anisotropy, and NMR spectroscopy to perform a detailed structural and biophysical characterization of the interaction between the two proteins and elucidate its molecular mechanism, which have so far been studied using cell-based methods. We show that the p53 tetramerization domain, p53(326-355), binds directly to residues 1-35 and 47-57 in Tat. We have characterized the interaction between p53(326-355) and Tat(47-57) in detail. The p53 residues that are mainly involved in binding to Tat(47-57) are E343 and E349, which bind to the positively charged arginine-rich motif of Tat by a partly electrostatic mechanism. All oligomerization states of p53(326-355) bind Tat(47-57) without inhibiting p53 tetramerization, since the residues in p53(326-355) that bind Tat(47-57) face away from the tetramerization interface. We conclude that p53 is able to bind Tat as a transcriptionally active tetramer.

Drug 9AA reactivates p21/Waf1 and Inhibits HIV-1 progeny formation

It has been demonstrated that the p53 pathway plays an important role in HIV-1 infection. Previous work from our lab has established a model demonstrating how p53 could become inactivated in HIV-1 infected cells through binding to Tat. Subsequently, p53 was inactivated and lost its ability to transactivate its downstream target gene p21/waf1. P21/waf1 is a well-known cdk inhibitor (CKI) that can lead to cell cycle arrest upon DNA damage. Most recently, the p21/waf1 function was further investigated as a molecular barrier for HIV-1 infection of stem cells. Therefore, we reason that the restoration of the p53 and p21/waf1 pathways could be a possible theraputical arsenal for combating HIV-1 infection. In this current study, we show that a small chemical molecule, 9-aminoacridine (9AA) at low concentrations, could efficiently reactivate p53 pathway and thereby restoring the p21/waf1 function. Further, we show that the 9AA could significantly inhibit virus replication in activated PBMCs, likely through a mechanism of inhibiting the viral replication machinery. A mechanism study reveals that the phosphorylated p53ser15 may be dissociated from binding to HIV-1 Tat protein, thereby activating the p21/waf1 gene. Finally, we also show that the 9AA-activated p21/waf1 is recruited to HIV-1 preintegration complex, through a mechanism yet to be elucidated.

HIV infection is associated with an increased risk for lung cancer, independent of smoking

BACKGROUND

Human immunodeficiency virus (HIV)-infected persons have an elevated risk for lung cancer, but whether the increase reflects solely their heavy tobacco use remains an open question.

METHODS

The Acquired Immunodeficiency Syndrome (AIDS) Link to the Intravenous Experience Study has prospectively observed a cohort of injection drug users in Baltimore, Maryland, since 1988, using biannual collection of clinical, laboratory, and behavioral data. Lung cancer deaths were identified through linkage with the National Death Index. Cox proportional hazards regression was used to examine the effect of HIV infection on lung cancer risk, controlling for smoking status, drug use, and clinical variables.

RESULTS

Among 2086 AIDS Link to the Intravenous Experience Study participants observed for 19,835 person-years, 27 lung cancer deaths were identified; 14 of the deaths were among HIV-infected persons. All but 1 (96%) of the patients with lung cancer were smokers, smoking a mean of 1.2 packs per day. Lung cancer mortality increased during the highly active antiretroviral therapy era, compared with the pre-highly active antiretroviral therapy period (mortality rate ratio, 4.7; 95% confidence interval, 1.7-16). After adjusting for age, sex, smoking status, and calendar period, HIV infection was associated with increased lung cancer risk (hazard ratio, 3.6; 95% confidence interval, 1.6-7.9). Preexisting lung disease, particularly noninfectious diseases and asthma, displayed trends for increased lung cancer risk. Illicit drug use was not associated with increased lung cancer risk. Among HIV-infected persons, smoking remained the major risk factor; CD4 cell count and HIV load were not strongly associated with increased lung cancer risk, and trends for increased risk with use of highly active antiretroviral therapy were not significant.

CONCLUSIONS

HIV infection is associated with significantly increased risk for developing lung cancer, independent of smoking status.

Lung cancer in HIV infected patients: facts, questions and challenges

AIDS related mortality has fallen sharply in industrialised countries since 1996 following the introduction of highly active antiretroviral therapy. This has been accompanied by an increase in the proportion of deaths attributable to non-AIDS defining solid tumours, especially lung cancer. The risk of developing lung cancer seems to be higher in HIV infected subjects than in the general population of the same age, partly because the former tend more frequently to be smokers and, especially, intravenous drug users. The carcinogenic role of the antiretroviral nucleoside drugs and their interaction with smoking needs to be examined. Interestingly, there is no clear relationship between the degree of immunosuppression and the risk of lung cancer, so the reason for the increased risk is unknown. The mean age of HIV infected patients at the time of lung cancer diagnosis is 45 years and most are symptomatic. Lung cancer is diagnosed when locally advanced or metastatic (stage III-IV) in 75-90% of cases, similar to patients with unknown HIV status. Adenocarcinoma is the most frequent histological type. The prognosis is worse in HIV infected patients than in the general lung cancer population. Efficacy and toxicity data for chemotherapy and radiation therapy are few and imprecise. Surgery remains the treatment of choice for localised disease in patients with adequate pulmonary function and general good health, regardless of immune status. Prospective clinical trials are needed to define the optimal detection and treatment strategies for lung cancer in HIV infected patients.

Lung cancer, a new challenge in the HIV-infected population

HIV infection predisposes patients to AIDS-defining malignancies, some of which, such as Kaposi's sarcoma and non-Hodgkin lymphoma, can affect the lungs. In 1996, AIDS-related mortality started to fall sharply in industrialized countries following the introduction of highly active antiretroviral treatments (HAART). This was accompanied by an increase in the proportion of deaths attributable to non AIDS-defining solid tumors, and especially lung cancer (LC). The increased risk of LC relative to the general population of the same age seems to be due partly to a higher prevalence of smoking among HIV-infected subjects. The average age of HIV-infected patients at LC diagnosis is about 45 years. Most patients are symptomatic at diagnosis and have only mild or moderate immunosuppression. LC is diagnosed when it is locally advanced or metastatic (stages III-IV) in 75-90% of cases, as in patients with unknown HIV serostatus. Adenocarcinoma is the most frequent histologic type. The prognosis of LC is poorer in HIV-infected patients than in the general population. Data on the efficacy and toxicity of chemotherapy in this setting are rare and rather imprecise. Surgery remains the reference treatment for localized disease in patients with adequate functional status and general health, regardless of their immune status. Prospective clinical trials are needed to define the optimal LC treatment strategies in HIV-infected patients.

[Cancer and HIV infection: any association?]

PURPOSE

Morbidity and mortality related to neoplasia are increasing in HIV-infected patients. CURRENT KNOWLEDGE AND KEY-POINTS: The incidence of AIDS opportunistic infections dramatically decreased since the introduction of highly active antiretroviral therapy (HAART). Among AIDS-cancers, the incidences of Kaposi sarcoma and of cerebral lymphoma decreased in a same way than AIDS infections but the incidences of systemic non-Hodgkin lymphoma and of cervical cancer decreased less than the others and remain higher than in the general population. This suggests that other factors than the quantitative immune reconstitution could be implicated. The most recent and large studies have also shown a 1.7 to 3 fold increased risk of developing non-AIDS cancers in HIV-infected patients when compared to the general population without significant impact of HAART on incidence curves. These malignancies include Hodgkin disease, lung, anal, head and neck cancers, hemopathies, and conjunctival cancers.

PERSPECTIVES

Epidemiologic survey will help to define priorities in terms of prevention and screening in this specific population and to evaluate interventions which should be systematically proposed (alcohol and tobacco cessation programs, viral coinfection). The own roles of HIV itself and of antiretrovirals as prooncogenic factors need to be assessed.

Incidence and risk factors for the occurrence of non-AIDS-defining cancers among human immunodeficiency virus-infected individuals

BACKGROUND

The objective of this study was to determine the rates and predictors of non-AIDS-defining cancers (NADCs) among a cohort of human immunodeficiency virus (HIV)-infected individuals.

METHODS

The authors conducted a retrospective study of 4144 HIV-infected individuals who had 26,916 person-years of follow-up and who had open access to medical care at 1 of the United States military HIV clinics during the years 1988-2003. Cancer incidence rates were race specific and were adjusted for age; these were compared with national rates using logistic regression to assess predictors of NADC development.

RESULTS

One hundred thirty-three NADCs were diagnosed with a rate of 980 diagnoses per 100,000 person-years. The most frequent NADCs were skin carcinomas (basal cell and squamous cell), Hodgkin disease, and anal carcinoma. The results showed that there were higher rates of melanoma, basal and squamous cell skin carcinomas, anal carcinoma, prostate carcinoma, and Hodgkin disease among the HIV-infected cohort compared with age-adjusted rates for the general United States population. Predictors of NADCs included age older than 40 years (odds ratio [OR], 12.2; P < 0.001), Caucasian/non-Hispanic race (OR, 2.1; P < 0.001), longer duration of HIV infection (OR, 1.2; P < 0.001), and a history of opportunistic infection (OR, 2.5; P < 0.001). The use of highly active antiretroviral therapy (HAART) was associated with lower rates of NADCs (OR, 0.21; P < 0.001). A low CD4 nadir or CD4 count at diagnosis (< 200 cells/mL) was not predictive of NADCs.

CONCLUSIONS

The most frequent NADCs were primary skin malignancies. Melanoma, basal and squamous cell skin carcinomas, anal carcinoma, prostate carcinoma, and Hodgkin disease occurred at higher rates among HIV-infected individuals. The implementation of screening programs for these malignancies should be considered. Most risk factors for the development of NADCs are nonmodifiable; however, the use of HAART appeared to be beneficial in protecting against the development of malignant disease.

Malignancy-related causes of death in human immunodeficiency virus-infected patients in the era of highly active antiretroviral therapy

BACKGROUND

Before the introduction of highly active antiretroviral therapy (HAART), malignancies accounted for less than 10% of all deaths among human immunodeficiency virus (HIV)-infected patients. This figure may have increased, and the observed types of malignant disease may have been modified, as a result of decreased occurrence of opportunistic infections, the chronicity of HIV infection, the possible oncogenic role of HIV itself, and the aging of the HIV-infected population.

METHODS

All French hospital wards involved in the management of HIV infection were asked to prospectively document the deaths of HIV-infected patients in the year 2000. Underlying causes of death were defined using a standardized questionnaire.

RESULTS

Of a total of 964 deaths, 269 (28%) were attributable to malignancies. Acquired immunodeficiency virus (AIDS)-related malignancies were the underlying cause of 149 deaths (15%); among these malignancies were non-Hodgkin lymphoma (n = 105 [11%]), noncerebral lymphoma (n = 78 [median CD4 count, 86 x 10(6) per liter; interquartile range [IQR], 35-231 x 10(6) per liter), and primary cerebral lymphoma (n = 27 [median CD4 count, 20 x 10(6) per liter; IQR, 4-109 x 10(6) per liter). Kaposi sarcoma was associated with 40 deaths (4%), and cervical carcinoma was associated with 5 (0.5%). Non-AIDS-related malignancies were the underlying cause of 120 deaths (13%); these non-AIDS-related malignancies included 103 solid tumors (50 respiratory tumors, 19 hepatocarcinomas, 9 digestive tumors, and 6 anal tumors; median CD4 count, 218 x 10(6) per liter; IQR, 108-380 x 10(6) per liter) and 17 hemopathies (12 Hodgkin lymphomas, 4 myeloid leukemias, and 1 myeloma; median CD4 count, 113 x 10(6) per liter; IQR, 56-286 x 10(6) per liter). Compared with patients who died of other causes, patients who died of solid tumors were more likely to be male, to smoke, to be older, and to have higher CD4 counts.

CONCLUSIONS

Malignant disease has been a major cause of death among HIV-infected patients in industrialized nations since the introduction of HAART. Whereas lethal hemopathies and Kaposi sarcoma are associated with advanced immunosuppression, lethal solid tumors can occur in patients with controlled HIV infection.

Thrombospondin-1/HIV-1 tat protein interaction: modulation of the biological activity of extracellular Tat

Tat protein, a trans-activating factor of the human immunodeficiency virus type 1, acts also as an extracellular molecule modulating gene expression, cell survival, growth, transformation, and angiogenesis. Here we demonstrate that human thrombospondin-1 (TSP), a plasma glycoprotein and constituent of the extracellular matrix, binds to glutathione-S-transferase (GST)-Tat protein but not to GST. Scatchard plot analysis of the binding of free GST-Tat to immobilized TSP reveals a high-affinity interaction (Kd equal to 25 nM). Accordingly, TSP inhibits cell internalization and HIV-1 LTR trans-activating activity of extracellular Tat in HL3T1 cells with ID50 equal to 10-30 nM. Also, TSP inhibits cell interaction and mitogenic activity of extracellular Tat in T53 Tat-less cells. TSP is instead ineffective when administered after the interaction of Tat with cell surface heparan-sulfate proteoglycans has occurred, in keeping with its ability to prevent but not disrupt Tat/heparin interaction in vitro. Finally, TSP inhibits the autocrine loop of stimulation exerted by endogenous Tat in parental T53 cells. Accordingly, TSP overexpression inhibits cell proliferation, angiogenic activity, and tumorigenic capacity of stable T53 transfectants. Our data demonstrate the ability of TSP to bind to Tat protein and to affect its LTR trans-activating, mitogenic, angiogenic, and tumorigenic activity. These findings suggest that TSP may be implicated in the progression of AIDS and in AIDS-associated pathologies by modulating the bioavailability and biological activity of extracellular Tat.

Loss of G(1)/S checkpoint in human immunodeficiency virus type 1-infected cells is associated with a lack of cyclin-dependent kinase inhibitor p21/Waf1

Productive high-titer infection by human immunodeficiency virus type 1 (HIV-1) requires the activation of target cells. Infection of quiescent peripheral CD4 lymphocytes by HIV-1 results in incomplete, labile reverse transcripts and lack of viral progeny formation. An interplay between Tat and p53 has previously been reported, where Tat inhibited the transcription of the p53 gene, which may aid in the development of AIDS-related malignancies, and p53 expression inhibited HIV-1 long terminal repeat transcription. Here, by using a well-defined and -characterized stress signal, gamma irradiation, we find that upon gamma irradiation, HIV-1-infected cells lose their G(1)/S checkpoints, enter the S phase inappropriately, and eventually apoptose. The loss of the G(1)/S checkpoint is associated with a loss of p21/Waf1 protein and increased activity of a major G(1)/S kinase, namely, cyclin E/cdk2. The p21/Waf1 protein, a known cyclin-dependent kinase inhibitor, interacts with the cdk2/cyclin E complex and inhibits progression of cells into S phase. We find that loss of the G(1)/S checkpoint in HIV-1-infected cells may in part be due to Tat's ability to bind p53 (a known activator of the p21/Waf1 promoter) and sequester its transactivation activity, as seen in both in vivo and in vitro transcription assays. The loss of p21/Waf1 in HIV-1-infected cells was specific to p21/Waf1 and did not occur with other KIP family members, such as p27 (KIP1) and p57 (KIP2). Finally, the advantage of a loss of the G(1)/S checkpoint for HIV-1 per se may be that it pushes the host cell into the S phase, which may then allow subsequent virus-associated processes, such as RNA splicing, transport, translation, and packaging of virion-specific genes, to occur.