Performance of OncoE6 cervical test with collection methods enabling self-sampling.

BACKGROUND: The paradigm shift from cytological screening to Human Papillomavirus (HPV)-based screening for cervical cancer allows the introduction of new technologies in sample collection and diagnostics. The OncoE6™ Cervical Test (OncoE6 Test) is a rapid, easy-to-use lateral flow method detecting HPV16/18 E6 oncoproteins that has proven to detect high-grade cervical lesions with high specificity. If compatible with self-collection samples, this technology might allow for decentralized screening of hard-to-reach populations. METHODS: For technical validation, cervicovaginal lavages were collected from 20 patients with confirmed HPV16+ or HPV18+ invasive cervical cancer. Cervical smears were collected by polyester-tipped swabs and cytobrushes. All samples were applied to the OncoE6 Test and cytobrush samples additionally genotyped. RESULTS: Lavage, swab, and cytobrush revealed concordant outcome in 18/20 samples. HPV types corresponded with the HPV genotyping by GP5+/6+ PCR analyses. Due to a rare mutation found in the E6 antibody binding site one sample was not detected, another sample had very low cellularity. CONCLUSIONS: Overall, vaginal lavages are technically adequate for the OncoE6 Test. Combining self-sampling with oncoprotein rapid testing to detect women with highest risk for severe dysplasia or cancer may allow for secondary cancer prevention in settings where other screening modalities were unsuccessful to date.

Lower cost strategies for triage of human papillomavirus DNA-positive women.

Using human papillomavirus (HPV) testing for cervical cancer screening in lower-resource settings (LRS) will result in a significant number of screen-positive women. This analysis compares different triage strategies for detecting cervical precancer and cancer among HPV-positive women in LRS. This was a population-based study of women aged 25-65 years living in China (n = 7,541). Each woman provided a self-collected and two clinician-collected specimens. The self-collected and one clinician-collected specimen were tested by two HPV DNA tests-careHPV™ and Hybrid Capture 2; the other clinician-collected specimen was tested for HPV16/18/45 E6 protein. CareHPV™-positive specimens were tested for HPV16/18/45 DNA. HPV DNA-positive women underwent visual inspection with acetic acid (VIA) and then colposcopic evaluation with biopsies. The performance for detection of cervical intraepithelial neoplasia grade 3 or cancer (CIN3+) among HPV DNA-positive women was assessed for different triage strategies: HPV16/18/45 E6 or DNA detection, VIA, colposcopic impression, or higher signal strength (≥10 relative light units/positive control [rlu/pc]). The percent triage positive ranges were 14.8-17.4% for VIA, 17.8-20.9% for an abnormal colposcopic impression; 7.9-10.5% for HPV16/18/45 E6; 23.4-28.4% for HPV16/18/45 DNA; and 48.0-62.6% for higher signal strength (≥10 rlu/pc), depending on the HPV test/specimen combination. The positivity for all triage tests increased with severity of diagnosis. HPV16/18/45 DNA detection was approximately 70% sensitive and had positive predictive values (PPV) of approximately 25% for CIN3+. HPV16/18/45 E6 detection was approximately 50% sensitive with a PPV of nearly 50% for CIN3+. Different triage strategies for HPV DNA-positive women provide important tradeoffs in colposcopy or treatment referral percentages and sensitivity for prevalent CIN3+.

Association of elevated E6 oncoprotein with grade of cervical neoplasia using PDZ interaction-mediated precipitation of E6.

OBJECTIVE: To determine the expression of human papillomavirus (HPV) type 16 E6 oncoprotein in cervical specimens of women with and without cervical intraepithelial neoplasia (CIN). MATERIALS AND METHODS: Cervical specimens from 2,530 unscreened women aged 30 to 54 years from Shanxi, China, were obtained. All women were assessed by liquid-based cytology, high-risk HPV DNA tests, and colposcopy with directed biopsy and endocervical curettage as necessary. Women with abnormal cytologic results or positive HPV DNA results were recalled for colposcopy, 4-quadrant cervical biopsies, and endocervical curettage. Women with biopsy-proven CIN and cancer and a convenience sample of HC2-positive, disease-negative women were tested for the presence of HPV-16 infection via HPV-16 E6 DNA-specific polymerase chain reaction. A PDZ interaction-mediated E6 oncoprotein precipitation method followed by E6-specific Western blot was performed on specimens from women with HPV-16 infections. Associations between elevated expression of E6 oncoprotein and CIN 2 and 3 were determined using logistic regression and a reference category of CIN 1 and disease-negative. RESULTS: A significant trend for the detection of HPV-16 E6 oncoprotein in specimen of women with proven HPV-16 infection was determined: 0% (0/12), 12.5% (1/8), 36.4% (4/11), and 42.9% (3/7) of those with negative findings, CIN 1, 2, and 3, respectively (p = .01). Compared with the category combining negative findings and CIN 1, detection of E6 oncoprotein was associated with CIN 2 (odds ratio = 10.9, p = .05) and CIN 3 (odds ratio = 14.3, p = .04). CONCLUSIONS: There is a significant association between elevated expression of E6 oncoprotein and grade of CIN. This finding seems consistent with the role played by E6 oncoprotein in carcinogenesis.

Feasibility study of a human papillomavirus E6 oncoprotein test for diagnosis of cervical precancer and cancer.

In a feasibility study using a prototype, lateral-flow test for human papillomavirus type 16, 18, and/or 45 (HPV16/18/45) E6 oncoproteins, 51 of 75 (68%; 95% confidence interval [95% CI] of 56 to 78%) of HPV16/18/45 DNA-positive specimens from women with a diagnosis of CIN3+ (cervical intraepithelial neoplasia grade 3+ or cervical cancer) tested positive for HPV16/18/45 E6 oncoprotein. None of 16 (95% CI of 0 to 37%) HPV16/18/45 DNA-positive cervical specimens from women with a negative or CIN1 diagnosis tested positive for HPV16/18/45 E6 oncoprotein.

Detection of HPV E6 oncoprotein from urine via a novel immunochromatographic assay.

Cervical cancer is a significant public health problem, especially in low- and middle-income countries, where women have little access to cervical cancer screening; consequently 80% of cervical cancer related mortality occurs in these regions. The development of screening methods that need less infrastructure thus represents an urgent medical need. The study aims to compare the detection rates of high-risk human papillomavirus 16 and 18 E6 oncoprotein in urine, vaginal self-collected, and cervical scrapes of women using the OncoE6™ Cervical Test and compare the HPV16 and/or HPV18 E6 detection rates with the HPV DNA testing. Paired urine, vaginal self-collected and cervical specimens were collected from 124 women who participated in cervical cancer screening or treatment in this proof-of-concept study and underwent to HPV16/18-E6 testing and high-risk HPV DNA testing prior to treatment of cervical neoplasia or cancer. Concordance between urinary, vaginal and cervical HPV16/18-E6 and HPV-DNA testing was evaluated for patients classified as negative group (

Cultural adaptation of internet interventions for refugees: Results from a user experience study in Germany.

BACKGROUND: The estimated number of refugees worldwide resulting from persecution, conflict, violence, or human rights violations reached 25.4 million in 2017. An increased prevalence of mental disorders combined with language and socio-cultural barriers pose a challenge for healthcare systems. Internet-based interventions can help to meet this challenge. For the effective use of such interventions in refugees, cultural adaptations are necessary. The variety of their cultural backgrounds thereby is particularly challenging. METHODS: We conducted this explorative qualitative study in order to identify elements of Internet-based interventions that need cultural adaptation to be suitable for refugees. Six refugees from Syria, Iran, Eritrea, Algeria, and Iraq, and six healthcare providers (two social workers, two psychologists, one physiotherapist, one physician) working with refugees went through an intervention for individuals with sleeping problems (eSano Sleep-e). Possible threats to user experience were identified using the Think Aloud method and semi-structured interviews. Statements were analysed based on the grounded theory method. RESULTS: Results indicate the necessity to adapt the intervention to the specifics of refugees including aspects related to the flight (i.e., past and current stressors) and non-western characteristics (i.e., habits, disease and treatment concepts). Elements of adaptation should include pictures, role models, language, psychoeducational elements, structure of modules, and format of presentation. CONCLUSIONS: Cultural adaptation can be used to facilitate the identification with an intervention, which seems crucial to increase the acceptance among refugees. In spite of their diverse cultural backgrounds, it appears feasible to create interventions that allow identification by refugees from different home countries.

PDZ protein interactions underlying NMDA receptor-mediated excitotoxicity and neuroprotection by PSD-95 inhibitors.

In neuronal synapses, PDZ domains [postsynaptic density-95 (PSD-95)/Discs large/zona occludens-1] of PSD-95 proteins interact with C termini of NMDA receptor [NMDAR (NR)] subunits, linking them to downstream neurotoxic signaling molecules. Perturbing NMDAR/PSD-95 interactions with a Tat peptide comprising the nine C-terminal residues of the NR2B subunit (Tat-NR2B9c) reduces neurons' vulnerability to excitotoxicity and ischemia. However, NR subunit C termini may bind many of >240 cellular PDZs, any of which could mediate neurotoxic signaling independently of PSD-95. Here, we performed a proteomic and biochemical analysis of the interactions of all known human PDZs with synaptic signaling proteins including NR1, NR2A-NR2D, and neuronal nitric oxide synthase (nNOS). Tat-NR2B9c, whose interactions define PDZs involved in neurotoxic signaling, was also used. NR2A-NR2D subunits and Tat-NR2B9c had similar, highly specific, PDZ protein interactions, of which the strongest were with the PSD-95 family members (PSD-95, PSD-93, SAP97, and SAP102) and Tax interaction protein 1 (TIP1). The PSD-95 PDZ2 domain bound NR2A-NR2C subunits most strongly (EC50, approximately 1 microM), and fusing the NR2B C terminus to Tat enhanced its affinity for PSD-95 PDZ2 by >100-fold (EC50, approximately 7 nM). IC50 values for Tat-NR2B9c inhibiting NR2A-NR2C/PSD-95 interactions (approximately 1-10 microM) and nNOS/PSD-95 interactions (200 nM) confirmed the feasibility of such inhibition. To determine which of the PDZ interactions of Tat-NR2B9c mediate neuroprotection, one of PSD-95, PSD-93, SAP97, SAP102, TIP1, or nNOS expression was inhibited in cortical neurons exposed to NMDA toxicity. Only neurons lacking PSD-95 or nNOS but not PSD-93, SAP97, SAP102, or TIP1 exhibited reduced excitotoxic vulnerability. Thus, despite the ubiquitousness of PDZ domain-containing proteins, PSD-95 and nNOS above any other PDZ proteins are keys in effecting NMDAR-dependent excitotoxicity. Consequently, PSD-95 inhibition may constitute a highly specific strategy for treating excitotoxic disorders.

Comparison of selective AT1-receptor blockade versus ACE inhibition for restenosis prophylaxis in patients with peripheral occlusive arterial disease after stent angioplasty: a randomized, controlled, proof-of-concept study.

Different components of the renin-angiotensin system (RAS) have been demonstrated in atherosclerotic plaques. However, the involvement of the RAS in the complex process of in-stent restenosis is not yet clear. In this prospective, randomized, double-blind, controlled proof-of-concept study, we compared the 2 different pharmacological approaches, selective AT(1)-receptor-blockade with candesartan vs ACE inhibition with quinapril to reduce in-stent restenosis after stent angioplasty of the superficial femoral artery. Twenty-two hypertensive patients with stage IIb peripheral occlusive arterial disease and severe claudication who had been successfully treated with percutaneous transluminal angioplasty (PTA) and stent implantation were randomly assigned to receive daily doses of either candesartan (32 mg) or quinapril (20 mg). Primary end point was restenosis 6 months after intervention, assessed by angiography. Secondary end points were pain-free walking distance, determined by treadmill ergometry; determination of crurobrachial indices; and intima-media thickness (IMT). At 6 months, the rate of restenosis on angiography was 34% in the candesartan group and 71% in the quinapril group (P = .043). Relevant restenosis was found in 3 patients (27%) in the candesartan group and in 7 patients (64%) in the quinapril group. Patients in the candesartan group were able to walk farther on a treadmill (increase: 135 m +/- 20 m) compared with patients in the quinapril group (increase: 83 m +/- 21 m). The IMT at the stent edge was not significantly different in the 2 groups (candesartan: 1.9 mm +/- 0.5 mm; quinapril: 2.0 mm +/- 0.3 mm). This study revealed significant benefit of a pharmacological restenosis regimen using the AT(1)-receptor antagonist candesartan in patients with severe atherosclerosis after superficial femoral artery stenting compared with treatment with the ACE inhibitor quinapril. Further prospective studies in patients are required to confirm these results.

Intracellular Analysis of the Interaction between the Human Papillomavirus Type 16 E6 Oncoprotein and Inhibitory Peptides.

Oncogenic types of human papillomaviruses (HPVs) cause cervical cancer and other malignancies in humans. The HPV E6 oncoprotein is considered to be an attractive therapeutic target since its inhibition can lead to the apoptotic cell death of HPV-positive cancer cells. The HPV type 16 (HPV16) E6-binding peptide pep11, and variants thereof, induce cell death specifically in HPV16-positive cancer cells. Although they do not encompass the LxxLL binding motif found in cellular HPV16 E6 interaction partners, such as E6AP, the pep11 variants strongly bind to HPV16 E6 by contacting the recently identified E6AP binding pocket. Thus, these peptides can serve as prototype E6-inhibitory molecules which target the E6AP pocket. We here analyzed their intracellular interaction with HPV16 E6. By comprehensive intracellular binding studies and GST pull-down assays, we show that E6-binding competent pep11 variants induce the formation of a trimeric complex, consisting of pep11, HPV16 E6 and p53. These findings indicate that peptides, which do not contain the LxxLL motif, can reshape E6 to enable its interaction with p53. The formation of the trimeric HPV16 E6 / peptide / p53 complex was associated with an increase of endogenous HPV16 E6 protein amounts. Yet, total cellular p53 amounts were also increased, indicating that the E6 / E6AP-mediated degradation of p53 is blocked. These findings suggest that inhibition of oncogenic activities by targeting the E6AP pocket on HPV16 E6 could be a strategy for therapeutic intervention.

Use of abciximab and tirofiban in patients with peripheral arterial occlusive disease and arterial thrombosis.

Acute peripheral arterial occlusive disease is an important factor affecting the mobility and mortality rate of elderly patients. Catheter-guided arterial thrombolysis in these patients has its limitations: long lysis times, early occlusions, and high restenosis rates. The study investigated whether the use of tirofiban has the same favorable effect as the glycoprotein (GP) IIb/IIIa receptor antagonist abciximab and whether lysis times can be shortened and the disease course positively influenced by these substances. Sixty patients were randomly assigned to 2 groups. Each group received 5 mg recombinant tissue-type (rt-PA) plasminogen activator by slow intra-arterial injection for 10 minutes followed by 5 mg rt-PA per hour and 500 IU heparin per hour IV. After randomization 1 group received a bolus of 0.25 mg abciximab per kg body weight followed by 10 mg per minute IV for 12 hours (heparin was reduced to 250 IU/hr). The other group received a bolus of 0.4 microg tirofiban per kg body weight as well as postinterventional medication with 0.1 microg tirofiban per minute and kg body weight for 24 hours. During medication with GP IIb/IIIa inhibitor, the patients received a reduced heparin dosage for 24 hours. After 24 hours both groups received 200 mg aspirin orally and full heparinization controlled on the basis of the partial thromboplastin time. The following efficacy criteria were analyzed: rehospitalization events, reintervention events, and amputations within 6 months. Secondary endpoints were changes in the Fontaine stage, the crurobrachial index, the distance to claudication, and the duration of local arterial lysis. No significant differences were found between the abciximab and tirofiban groups in terms of the rehospitalization, reintervention, or amputation rates, nor were there any group differences in the total number of events. The secondary parameters, such as the crurobrachial index, distance to claudication, and Fontaine stage, also showed no significant differences between the 2 groups within 6 months. The duration of lysis was significantly shorter in the abciximab group. Major bleeding events did not occur in either group. With regard to the adverse effect rate, there were no significant differences between the 2 groups. Both abciximab and tirofiban can be used successfully in patients with peripheral arterial occlusive disease and arterial thrombosis.

An evaluation of novel, lower-cost molecular screening tests for human papillomavirus in rural China.

New, lower-cost tests that target high-risk human papillomavirus (HR-HPV) have been developed for cervical cancer screening in lower-resource settings but large, population-based screening studies are lacking. Women ages 25 to 65 years and living in rural China (n = 7,543) self-collected a cervicovaginal specimen, had 2 cervical specimens collected by a clinician, and underwent visual inspection after acetic acid (VIA). The self- and one clinician-collected specimens underwent HR-HPV DNA testing by careHPV (QIAGEN) and Hybrid Capture 2 (HC2; QIAGEN) and the other clinician-collected specimen was tested for HPV16, 18, and 45 E6 using OncoE6 (Arbor Vita Corporation). Women who screened positive for any test and a random sample of those negative on all tests underwent colposcopic evaluation. The percent test positive was 1.8% for HPV E6 oncoprotein, between 14% and 18% for HR-HPV DNA testing, and 7.3% for VIA. The sensitivity for cervical intraepithelial neoplasia grade 3 or more severe (CIN3(+); n = 99) was 53.5% for OncoE6, 97.0% for both careHPV and HC2 testing of the clinician-collected specimen, 83.8% for careHPV testing and 90.9% for HC2 testing of the self-collected specimen, and 50.5% for VIA. OncoE6 had the greatest positive predictive value (PPV), at 40.8% for CIN3(+), compared with the other tests, which had a PPV of less than 10%. OncoE6 tested 70.3% positive for HPV16, 18, or 45-positive CIN3(+) and tested negative for all HPV16-, 18-, or 45-negative CIN3(+) (P < 0.0001). HPV E6 oncoprotein detection is useful for identifying women who have cervical precancer and cancer.

Cervical cancers require the continuous expression of the human papillomavirus type 16 E7 oncoprotein even in the presence of the viral E6 oncoprotein.

High-risk human papillomaviruses (HPV), such as HPV-16, are etiologic agents of a variety of anogenital and oral malignancies, including nearly all cases of cervical cancer. Cervical cancers arising in transgenic mice that express HPV-16 E7 in an inducible manner require the continuous expression of E7 for their maintenance. However, in HPV-associated cancers in vivo, E6 and E7 invariably are coexpressed. In this study, we investigated whether cervical cancers rely on the continuous expression of E7 in the context of constitutively expressed E6. We placed the inducible HPV-16 E7 transgene onto a background in which HPV-16 E6 was constitutively expressed. In transgenic mice with high-grade cervical dysplastic lesions and cervical cancer, repressing the expression of E7 led to the regression of all cancers and the vast majority of high-grade dysplastic lesions. In addition, cervical cancers were occasionally observed in transgenic mice in which E7 was repressed and then reexpressed. Our findings indicate that even in the presence of constitutively expressed E6, the continuous expression of E7 is required for the maintenance of cervical cancers and most precancerous lesions. These data have important implications for the potential clinical use of drugs designed to inhibit the expression and/or function of E7 to treat HPV-associated cancers.

Efficacy and tolerability of aliskiren 300 mg/hydrochlorothiazide 25 mg (± amlodipine 5 mg) in hypertensive patients not controlled by candesartan 32 mg plus HCT 25 mg.

AIMS: The majority of patients with essential hypertension of moderate severity (WHO grade 2) require combination therapy. We aimed to investigate whether the single-pill combination of aliskiren 300 mg and hydrochlorothiazide (HCT) 25 mg (ALIS 300/HCT 25) improves the BP reduction in hypertensive patients not adequately controlled by the free combination of candesartan 32 mg and HCT 25 mg (CAN 32 + HCT 25). METHODS: In an open-label, single-arm study, patients with mean sitting diastolic blood pressure (DBP) between 100-109 mmHg at baseline received 4-week treatment with CAN 32 + HCT 25 (Phase 1), followed - in patients whose BP was not controlled - by 4-week treatment with ALIS 300/HCT 25 (Phase 2). The DBP change between weeks 4 and 8 was the primary endpoint. The ClinicalTrials.gov Identifier is NCT00867490. RESULTS: In the 186 patients treated, CAN 32 + HCT 25 reduced systolic BP (SBP)/DBP by 18.9/12.2 mmHg. Those 123 patients with uncontrolled hypertension switched to ALIS 300/HCT 25 experienced a further SBP/DBP reduction of 2.8/3.1 mmHg between week 4 and week 8 (p = 0.0064 and p < 0.0001), and 33.3% achieved DBP normalisation. In 61 patients not controlled after week 8 (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg), who participated in an optional study extension, amlodipine 5 mg was added. Triple therapy over 4 weeks decreased SBP/DBP by further 9.2/5.9 mmHg (p < 0.0001 each). Adverse events with suspected drug relationship were noted in 4.3% (Phase 1), 3.3% (Phase 2), and 1.6% (extension) of the patients. Limitations of the study include the open-label, non-randomised approach and short treatment duration across the individual phases. CONCLUSIONS: In this open-label, single-arm switch study reflecting clinical practice, patients with moderate hypertension not controlled by the free combination of CAN 32 + HCT 25 achieved a clinically and statistically significant reduction of blood pressure from the single pill combination of ALIS 300/HCT 25, and the optional addition of amlodipine.

[Current status of antihypertensive drug treatment in primary care practice at launch of the new renin inhibitor aliskiren (RASANT)]. / Status der Behandlung der arteriellen Hypertonie unter Praxisbedingungen in deutschen Arztpraxen zum Zeitpunkt der Einführung des Renininhibitors Aliskiren.

PURPOSE: The present drug utilization research project was conducted in order to evaluate the current status of antihypertensive drug treatment at launch of aliskiren - a drug targeting a completely new pharmacological mode of action - and to investigate the potential therapeutic value of this new therapeutic principle. METHODS: In 1,431 primary care practices in Germany, general practitioners and internal specialists were requested to determine the therapeutic value of different antihypertensive drugs (3rd and 4th quarter of 2007). Physicians were also requested to expose potential advantages of the new therapeutic principle of direct renin inhibition. Additional epidemiologic data such as age, gender and comorbidities were collected for each antihypertensive patient considered an optimal candidate to receive aliskiren in the respective medical practice due to an unfavorable response to the current antihypertensive treatment by using a second questionnaire. RESULTS: On a scale between 1 (very important) and 6 (unimportant), the therapeutic value of antihypertensive drugs was judged as follows: angiotensin-inhibiting enzyme (ACE) inhibitors (98.8%), angiotensin (AT)(1) receptor blockers (87.4%), beta-receptor blockers (71.2%), calcium channel blockers (58.9%), thiazide diuretics (56,3%), and loop diuretics (32.3%) were judged with the mark 1 (very important) and 2 (important). From a total of 14,358 patients included in the present survey, age, gender, severity and duration of arterial hypertension, complications and comorbidities, and a detailed drug history were collected. 50.3% of the patients received an ACE inhibitor, 27.9% an AT(1) receptor blocker, 45.7% a beta-receptor blocker, 37.5% a calcium channel blocker, and 53.2% a diuretic. Dominating comorbidities up to the time of data collection were diabetes mellitus (43.8%), coronary heart disease (37.3%), and chronic heart failure (20.7%). 89.4% of patients with diabetes received either an ACE inhibitor or an AT(1) receptor blocker compared to 69.6% of patients not suffering from diabetes. CONCLUSION: According to the evaluation of primary care physicians participating in this study, aliskiren might be useful for antihypertensive treatment in patients with severe arterial hypertension, in patients with an already long-lasting course of disease, and in the presence of comorbidities such as diabetes mellitus. The high percentage of patients in this study cohort already treated with an ACE inhibitor or an AT(1) receptor blocker represents good adherence of primary care physicians to current treatment guidelines. The evaluation of loop diuretics as important antihypertensive drugs by 32.3% of attending physicians in this study requires critical discussion.

Telemedical support in patients with chronic heart failure: experience from different projects in Germany.

The great epidemiological significance and costs associated with chronic heart failure pose a challenge to health systems in Western industrial countries. In the past few years, controlled randomised studies have shown that patients with chronic heart failure benefit from telemedical monitoring; specifically, telemonitoring of various vital parameters combined with a review of the symptoms, drug compliance and patient education. In Germany, various telemedical monitoring projects for patients with chronic heart failure have been initiated in the past few years; seven of them are presented here. Currently 7220 patients are being monitored in the seven selected projects. Most patients (51.1%) are in NYHA stage II, 26.3% in NYHA stage III, 14.5% in NYHA stage I and only 6.6% in NYHA stage IV respectively. Most projects are primarily regional. Their structure of telemedical monitoring tends to be modular and uses stratification according to the NYHA stages. All projects include medical or health economics assessments. The future of telemedical monitoring projects for patients with chronic heart failure will depend on the outcome of these assessments. Only of there is statistical evidence for medical benefit to the individual patient as well as cost savings will these projects continue.

A mouse model for human anal cancer.

Human anal cancers are associated with high-risk human papillomaviruses (HPV) that cause other anogenital cancers and head and neck cancers. As with other cancers, HPV16 is the most common high-risk HPV in anal cancers. We describe the generation and characterization of a mouse model for human anal cancer. This model makes use of K14E6 and K14E7 transgenic mice in which the HPV16 E6 and E7 genes are directed in their expression to stratified squamous epithelia. HPV16 E6 and E7 possess oncogenic properties including, but not limited to, their capacity to inactivate the cellular tumor suppressors p53 and pRb, respectively. Both E6 and E7 were found to be functionally expressed in the anal epithelia of K14E6/K14E7 transgenic mice. To assess the susceptibility of these mice to anal cancer, mice were treated topically with dimethylbenz[a]anthracene (DMBA), a chemical carcinogen that is known to induce squamous cell carcinomas in other sites. Nearly 50% of DMBA-treated HPV16 E6/E7 transgenic mice showed overt signs of tumors, whereas none of the like-treated nontransgenic mice showed tumors. Histopathologic analyses confirmed that the HPV16 transgenic mice were increased in their susceptibility to anal cancers and precancerous lesions. Biomarker analyses demonstrated that these mouse anal cancers exhibit properties that are similar to those observed in HPV-positive precursors to human anal cancer. This is the first mouse model for investigating the contributions of viral and cellular factors in anal carcinogenesis, and should provide a platform for assessing new therapeutic modalities for treating and/or preventing this type of cancer.

Formation of well-defined soluble aggregates upon fusion to MBP is a generic property of E6 proteins from various human papillomavirus species.

Protein aggregation is a main barrier hindering structural and functional studies of a number of interesting biological targets. The E6 oncoprotein of Human Papillomavirus strain 16 (E6(16)) is difficult to express under a native soluble form in bacteria. Produced as an unfused sequence, it forms inclusion bodies. Fused to the C-terminus of MBP, it is mainly produced in the form of soluble high molecular weight aggregates. Here, we produced as MBP-fusions seven E6 proteins from other HPV strains (5, 11, 18, 33, 45, 52, and 58) belonging to four different species, and we compared their aggregation state to that of MBP-E6(16). Using a fast mutagenesis method, we changed most non-conserved cysteines to the isosteric residue serine to minimize disulfide bridge-mediated aggregation during purification. Static and dynamic light scattering measurements, ultracentrifugation and electron microscopy demonstrated the presence in all MBP-E6 preparations of soluble high-molecular weight aggregates with a well-defined spherical shape. These aggregated particles are relatively monodisperse but their amount and their size vary depending on the conditions of expression and the strain considered. For all strains, minimal aggregate formation occurs when the expression is performed at 15 degrees C. Such observations suggest that the assembly of MBP-E6 aggregates takes place in vivo during protein biosynthesis, rather than occurring during purification. Finally, we show that all MBP-E6 preparations contain two zinc ions per protein monomer, suggesting that E6 domains within the high molecular weight aggregates possess a native-like fold, which enables correct coordination to the metal center.