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In oncology, the identification of targets that correlate with a type of cancer has led to a profound change in the notion of "tumor markers". Technological advances, in particular the development of high-throughput sequencing, have led to the emergence of a new generation of molecular biomarkers for tumors. Despite their limited utility for screening and diagnosis, conventional tumor markers remain interesting for evaluation of prognoses, the choice and optimization of treatments, as well as for monitoring the effectiveness of those treatments. In this article, we revisit the conventional serum markers that are enjoying a 'come back' thanks to the development of high-performance scores based on biological, cytological, clinical, or radiological criteria.

International audience; The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from liquid biopsies has become an important requirement for clinical diagnostics and personalized medicine. In particular, the simultaneous detection of wild-type (WT) dsDNA and their cancer-related counterparts presenting single-point mutations with simple, sensitive, specific, and reproducible technologies is paramount for ctDNA assays in clinical practice. Here, we present the development and evaluation of an amplified dsDNA assay based on a combination of isothermal rolling circle amplification (RCA) and time-gated Förster resonance energy transfer (TG-FRET) between a Tb donor and two dye (Cy3.5 and Cy5.5) acceptors. The RCA–FRET assay is free of washing and separation steps and can quantify both WT and mutated (MT) (V600E) dsDNA in the BRAF gene from a single sample in the 75 fM to 4.5 pM (4.5 × 105 to 2.7 × 107 copies) concentration range. This assay includes all steps from denaturation of the dsDNA targets to the final duplexed quantification of WT and MT targets. High assay performance at different dsDNA sequence lengths and high target specificity even in the presence of a large excess of nonspecific cell-free DNA from human plasma samples demonstrated the applicability to clinical samples. The RCA–FRET single-point mutation sensor has the potential to become an important complementary technique for analyzing liquid biopsies in advanced cancer diagnostics.

Aim Despite unprecedented results of anti-programmed death protein (ligand) 1 (PD-(L)1) immune checkpoint inhibitor in the oncology's armamentarium, immune-related adverse events (irAEs) represent a therapeutic hurdle. Currently, there is no consensual recommendation on a routinely monitored biomarker to early detect irAE. Biological markers such as serum creatine phosphokinase (CPK) are commonly used to measure muscular tissue injury. The potential of routine serum CPK monitoring to predict cardiac or neuromuscular irAE in patients treated with immunotherapy remains unknown. Methods In this retrospective study between January 2016 and December 2018 at Gustave Roussy Cancer Campus, 1151 cancer patients treated with anti-PD–(L)1 immunotherapy were systematically monitored with serum CPK measurements before each immunotherapy cycle. We considered significant CPK increases according to Common Terminology Criteria for Adverse Events v5.0 (CTCAEV5) of grade ≥2 severity. Comparisons were performed in patients with immune-related CPK (ir-CPK) elevations symptomatic versus asymptomatic. Results Overall, 53 of 1151 (4.6%) patients showed a CPK increase. Elevations of CPK were deemed to be immunotherapy-related in 31 of 1151 (2.7%) patients. Among them, 12 of 31 (38.7%) patients experienced symptomatic cardiac or neuromuscular irAE, whereas the other 19 of 31 (61.3%) patients remained asymptomatic. In patients with symptomatic irAE, the mean ir-CPK level was higher compared with asymptomatic patients (1271 versus 771 UI/L, P value = 0.02). In the asymptomatic group, all patients experienced a spontaneous resolution of the ir-CPK increase, and none required medical intervention. Conclusion Most patients with immune-related CPK increase remained asymptomatic. The CPK serum increase did not alter the clinical management of asymptomatic patients. The results of this study did not support a significant clinical interest for a systematic routine CPK monitoring in patients amenable to anti-PD-(L)1 immunotherapy.

The quantification of very low concentrations of circulating tumor DNA (ctDNA) biomarkers from liquid biopsies has become an important requirement for clinical diagnostics and personalized medicine. In particular, the simultaneous detection of wild-type (WT) dsDNA and their cancer-related counterparts presenting single-point mutations with simple, sensitive, specific, and reproducible technologies is paramount for ctDNA assays in clinical practice. Here, we present the development and evaluation of an amplified dsDNA assay based on a combination of isothermal rolling circle amplification (RCA) and time-gated Förster resonance energy transfer (TG-FRET) between a Tb donor and two dye (Cy3.5 and Cy5.5) acceptors. The RCA-FRET assay is free of washing and separation steps and can quantify both WT and mutated (MT) (

Background Anti-PD1 and anti-PD-L1 are effective checkpoints inhibitors to stimulate the immune system against many types of cancers. The flip side of these immunotherapies is the generation of immune-related adverse events (irAE), which can theoretically affect all organs including muscle tissue. Immune-related creatine phosphokinase (irCPK) increase is associated with immune related myositis. The meaning of CPK monitoring in clinical practice remains poorly understood. In this observational study, all the grade ≥ 2 increased CPK occurring in patients treated with anti-PD-1 or anti-PD-L1 were investigated to determine their clinical significance. Methods All consecutive pts treated with anti-PD1 or anti-PD-L1, in monotherapy or in combine therapy with other agents, monitored by routine CPK in the Drug Development Department (DITEP) and in the Dermatology Unit of Gustave Roussy between January 2016 and December 2018 were retrospectively reviewed. Patients CPK monitoring level were extracted from biological chart and all the patients with grade ≥ 2 increased CPK were selected for the analysis. Results Among the 1151 patients treated with anti PD1/PD-L1, 53 (4.6%) had grade ≥ 2 increased CPK regardless of immune causality and 31 (2.7%) had a grade ≥ 2 irCPK increase. Among the 53 pts with CPK increase, mean age was 54 years old, tumor types were skin (n = 21), bladder and urothelial (n = 5), head and neck (n = 4) and others (n = 23). CPK increase was not related to the treatment in 22 (41%) pts, was immune-related to anti-PD1/PDL1 and not clinically significant in 19 (36%) pts, was immune-related with muscular adverse events in 10 (19%) pts, including 2 myositis and 2 acute polyradiculoneuritis; and was immune-related with myocarditis in 2 (4%) pts. The mean of CPK maximal peak was significantly higher in patients with immune-related cardiac or muscular adverse event that in the asymptomatic CPK increase pts (1271 UI/L vs. 771 UI/L, p-value = 0.02). Conclusions The frequency of grade ≥ 2 irCPK increase is estimated at 2.7% of patients treated with anti-PD1 or anti-PD-L1. For patients treated with anti PD1/PD-L1, regular CPK monitoring appears as clinically relevant in the early detection of immune-related cardiac and muscular adverse events. Legal entity responsible for the study Jean-Marie Michot. Funding Has not received any funding. Disclosure C. Baldini: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. P. Romano-Martin: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. P. Vuagnat: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. S. Champiat: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. A. Varga: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. A. Hollebecque: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. C. Robert: Advisory / Consultancy: Roche, BMS, MSD, Amgen, Novartis. C. Massard: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. O. Lambotte: Advisory / Consultancy: BMS, MSD, AstraZeneca, LFB, CSL Behring, Janssen. J. Michot: Advisory / Consultancy: Consultant/Advisory fees from Amgen, Astellas, AstraZeneca, Bayer, BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, Orion Principal/sub-Investigator of Clinical Trials for AbbVie, Aduro. All other authors have declared no conflicts of interest.

Le traitement par methotrexate haute dose necessite un suivi pharmacologique afin d’adapter les traitements de sauvegarde pour limiter les effets secondaires. L’etude realisee a ete menee afin de valider l’adaptation du reactif EMIT sur l’Unicel DxC 600 ® Beckman Coulter. La mise en place de deux methodes de dosages a ete necessaire afin d’obtenir une limite de quantification la plus faible possible (0,05 μmol/L). La linearite des methodes adaptees s’etend de 0,05 a 0,25 μmol/L d’une part, et de 0,25 a 1 μmol/L d’autre part. Pour chaque methode, les etudes de fidelite et de justesse ont ete realisees et les limites de detection et de quantification ont ete determinees. La correlation avec la methode FPIA a ete realise sur le TDX ® Abbott. Les resultats de l’ensemble des tests sont satisfaisants avec notamment des coefficients de variation (CV) de repetabilite et reproductibilite inferieurs a 6 %. Cependant la gestion quotidienne des dosages s’avere lourde puisque 66 % des echantillons recus necessitent au moins deux dosages et 30 % doivent etre dilues manuellement.

Ovarian yolk sac tumour (OYST) is a very rare malignancy arising most often in young women. Preoperative clinical, biological (alpha-foetoprotein) and radiological findings should help to establish the diagnosis of OYST, in order to propose adequate surgical treatment. The aim of surgery is to remove the primary tumour, to obtain an accurate histological diagnosis and to assess the disease extent. In young women, fertility-sparing surgery should be performed, in order to preserve the possibility of pregnancy later on. Chemotherapy has substantially modified the prognosis of these tumours, and practically all patients will be cured. The overall 5-year survival rate is 94% when patients are treated with BEP chemotherapy. Depending on the clinical situation, two to four cycles of the BEP regimen should be administered after surgery. Identification of prognostic factors may help to propose risk-adapted treatment in order to increase the cure rate in patients with a poor prognosis and to decrease toxicity in patients with a low risk of relapse. Fertility preservation represents a major objective in women treated for OYSTs.

Background Ovarian yolk sac tumour (OYST) is a very rare malignancy arising in young women. Our study aimed to evaluate long-term outcomes and to identify prognostic parameters likely to help make appropriate risk-based decisions about therapy in this disease. Methods This retrospective study is based on prospectively recorded OYST cases at the Institut Gustave-Roussy. A univariate analysis using the logrank test evaluated possible associations between survival and patient or disease covariates. The multivariate analysis was performed using the Cox proportional hazard regression method. Results Between 1976 and 2006, 84 patients were registered. Since 1991, most of the patients have undergone fertility-sparing surgery. With a median follow-up of 71 months, the overall 5-year and event-free survival rates are 84% and 79%, respectively. In the multivariate model only the absence of ascites and a favourable serum AFP decline rate were significantly associated with better overall survival. Conclusions Patients with a poor prognosis factor such as an unfavourable serum AFP decline may be considered for aggressive treatment whereas those with good prognostic factors could be given less courses of chemotherapy.

Background No sensitive, specific marker able to discriminate favourable or unfavourable outcome of fever of unknown origin (FUO) at diagnosis has been identified. Procalcitonin, a recently assessed infection marker, may be useful in predicting the outcome of FUO. Methods We conducted a prospective study examining the following variables: age 0.5–22 years; solid tumour diagnosis; chemotherapy-related grade-4 febrile neutropenia (FN). A complete clinical, bacteriological and biological evaluation was performed at hospital admission (H0). Other investigations depended on clinical status. FUO was considered to be of unfavourable outcome if the fever was persistent or re-appeared at day 3 (or later), or if secondary clinical or microbiological infection occurred. To validate the results of the analysis the data set was randomly split into a training set and a validation set. Results Out of 172 episodes of FN, 136 episodes were classified as FUO (80%). Seventy-two (53%) were included in this study. PCT values were significantly higher in episodes of unfavourable outcome (P

International audience; EAA26 (VESMNEELKKIIAQVRAQAEHLKTAY) is a better inhibitor of human immunodeficiency virus, type 1, integrase than its parent Lys-159, reproducing the enzyme segment 147-175 with a nonpolar-polar/charged residue periodicity defined by four helical heptads (abcdefg) prone to collapse into a coiled-coil. Circular dichroism, nuclear magnetic resonance, sedimentation equilibrium, and chemical cross-linking were used to analyze EAA26 in various trifluoroethanol/H(2)O mixtures. In pure water the helix content is weak but increases regularly up to 50-60% trifluoroethanol. In contrast the multimerization follows a bell-shaped curve with monomers in pure water, tetramers at 10% trifluoroethanol, and dimers at 40% trifluoroethanol. All suggest that interhelical interactions between apolar side chains are required for the coiled-coil formation of EAA26 and subsist at medium trifluoroethanol concentration. The N(H) temperature coefficients measured by nuclear magnetic resonance show that at low trifluoroethanol concentration the amide groups buried in the hydrophobic interior of four alpha-helix bundles are weakly accessible to trifluoroethanol and are only weakly subject to its hydrogen bond strengthening effect. The increased accessibility of trifluoroethanol to buried amide groups at higher trifluoroethanol concentration entails the reduction of the hydrophobic interactions and the conversion of helix tetramers into helix dimers, the latter displaying a smaller hydrophobic interface. The better inhibitory activity of EAA26 compared with Lys-159 could arise from its better propensity to form a helix bundle structure with the biologically important helical part of the 147-175 segment in integrase.

Screening was performed in 130 consecutive patients with apparently sporadic neuroendocrine tumors (NET) to assess the prevalence of multiple endocrine neoplasia type 1 (MEN1) and hormonal production. Screening for MEN1 included measurement of serum calcium and PTH[ PTH-(1–84)], gastrin, PRL, and insulin-like growth factor type I (IGF-I) levels. MEN1 genetic testing was performed in patients with two components of the MEN1 syndrome. Screening for hormonal production included measurement of serum neuron-specific enolase (NSE), calcitonin (CT), glycoprotein α-subunit (GPα), hCG β-subunit (free hCGβ), and somatostatin levels. Twenty-four-hour urinary free cortisol (UFC) and 5-hydroxyindolacetic acid (5-HIAA) determinations were also performed. Four patients had hyperparathyroidism, none of whom had pituitary or familial disease. Hyperprolactinemia was compatible with a pituitary disease in one patient. No acromegalic feature or any increase in IGF-I was found. Hypergastrinemia, compatible with an associated ...

Antipeptide antibodies raised against the carboxyl-terminal region of the human sodium/iodide (Na+/I−) symporter (hNIS) were used to investigate by immunohistochemistry the presence and distribution of the hNIS protein in normal thyroid tissues, in some pathological nonneoplastic thyroid tissues, and in different histotypes of thyroid neoplasms. In normal thyroid tissue, staining of hNIS protein was heterogeneous and limited to a minority of follicular cells that were in close contact with capillary vessels. In positive cells, immunostaining was limited to the basolateral membrane. In contrast, in Graves’ disease the majority of follicular cells expressed the hNIS protein. In autoimmune thyroiditis, the number of hNIS-positive cells, was similar to that found in normal tissue. These positive cells were found essentially close to lymphocytic infiltrates. This observation supports the concept of hNIS as an autoantigen. In diffuse nodular hyperplasia, hNIS staining was heterogeneous, but the number of hNIS-positive cells exceeded that found in normal tissue. In well differentiated follicular or papillary carcinoma, the number of hNIS-positive cells was significantly lower than in normal tissue. In poorly differentiated follicular carcinoma, the number of hNIS-positive cells was less than that found in well differentiated carcinoma, or there were no positive cells. Interestingly, in all of these thyroid tissues, the number of follicular cells exhibiting TSH receptor (TSHR) immunoreactivity was greater than the number of hNIS-positive cells. As hNIS expression appears to be related to TSHR stimulation, the decreased number of TSHR-positive cells in cancers may contribute to the reduced capacity of neoplastic cells to concentrate iodide. In one patient with a follicular cancer with an absence of hNIS immunostaining, the total body 131I scan showed no uptake in metastatic tissue. In three cancers with positive hNIS cells, the 131I scan showed uptake in lymph node metastases. This suggests that immunodetection of hNIS could predict radioiodine uptake in thyroid cancers.

Human lutropin (hLH) exhibits both carbohydrate and peptidic heterogeneities that affect its biological potency and the duration of its activity in vivo. Peptidic changes within the hLH beta-subunit are characterized as intrachain proteolytic nicking and carboxyl terminus heterogeneity. To date, the carboxyl terminus of hLHbeta appears to end at either position Gln114 or Gly117, as determined by sequencing of purified subunit. Furthermore, the complementary DNA for hLHbeta predicts a protein containing an additional peptidic stretch, which would make the beta-subunit 121 residues long. This extension may be responsible for the particular intracellular behavior of hLHbeta. To investigate the carboxyl terminus polymorphism of natural hLHbeta, monoclonal antipeptide antibodies were raised against a synthetic peptide mimicking the 104-119 portion of hLHbeta. One antibody, designated LHP09, was found to specifically react with the recombinant hLHbeta ending at position hLHbeta[Leu119] but not with other recombinant forms ending at [Ser116], [Phe120] or [Leu121]. Immunochemical analysis of hLH, either pituitary or urinary in origin, indicated that only pituitary hLH contains a Leu119-ending form of hLHbeta. Finally, immunohistochemical detection was performed using LHP09 and showed specific staining of a normal adult pituitary gland. These observations support the in vivo existence of intrapituitary molecular forms of hLHbeta ending at various positions between Gln114 and Leu121.

The retinoblastoma tumour-suppressor protein Rb inhibits cell proliferation by repressing a subset of genes that are controlled by the E2F family of transcription factors and which are involved in progression from the G1 to the S phase of the cell cycle. Rb, which is recruited to target promoters by E2F1, represses transcription by masking the E2F1 transactivation domain and by inhibiting surrounding enhancer elements, an active repression that could be crucial for the proper control of progression through the cell cycle. Some transcriptional regulators act by acetylating or deacetylating the tails protruding from the core histones, thereby modulating the local structure of chromatin: for example, some transcriptional repressors function through the recruitment of histone deacetylases. We show here that the histone deacetylase HDAC1 physically interacts and cooperates with Rb. In HDAC1, the sequence involved is an LXCXE motif, similar to that used by viral transforming proteins to contact Rb. Our results strongly suggest that the Rb/HDAC1 complex is a key element in the control of cell proliferation and differentiation and that it is a likely target for transforming viruses.

In humans, intermediate basic proteins HPI1 and HPI2 are considered as common precursors of the P2 protamine family, according to data provided by structural studies of these proteins. The occurrence and fate of proteins HPI1 and HPI2 were investigated in nuclei of human spermatids and spermatozoa by means of immunoelectron microscopy. A specific polyclonal antibody against a synthetic peptide overlapping the N-terminus of HPI1 and HPI2 was prepared and used to detect these proteins on sections of testis and ejaculated sperm. A quantitative analysis of labelling density was performed on micrographs using an interactive image analysis system. The first signs of labelling of intermediate basic proteins appeared in spermatid nuclei at steps 4-5 of spermiogenesis, i.e. during the chromatin condensation process. The nuclear labelling density strongly increased in elongating spermatids (steps 5 and 6) and then sharply decreased from step 6 to step 8 of spermiogenesis. However, weak labelling persisted in the nuclei of mature spermatids and ejaculated spermatozoa. The present results show that the intermediate basic proteins HPI1 and HPI2 are synthesized in large amounts in human spermatids during elongation phase and disappear almost totally in mature spermatids when deposition of protamines is completed in condensed nuclei.

Recently, a new member of the insulin gene superfamily termed insulin-like 4 (INSL4) was identified in the human placenta and uterus. The present study investigated whether placenta translates INSL4 mRNA into a putative peptide named early placenta insulin-like (EPIL). Among antibodies elicited against the C chain of pro-EPIL, one antibody (AB7381) was specifically directed against the C chain 59-88 portion, and among those elicited against the A and B chains of EPIL, one antibody (Ab1661) was directed against the A chain 115-139 and the B chain 23-52 portions. Immunohistochemistry based on antibody 7381 to pro-EPIL and antibody 1661 to EPIL demonstrated that the cytotrophoblast from early placenta preferentially expresses the pro-EPIL peptide, whereas the EPIL peptide is expressed by both the cytotrophoblast and the syncytiotrophoblast. At term, the pro-EPIL peptide was detected in villous cytotrophoblast cells, whereas the EPIL peptide was not detected. Moreover, in vitro experiments performed on term placenta showed that the steady state levels of INLS-4 mRNA in the cytotrophoblast are 10 times (one log unit) lower than in the differentiated villous syncytiotrophoblast cells. Taken together, these findings reveal that expression of EPIL peptides in the villous cytotrophoblast is different from that displayed by the syncytiotrophoblast. Finally, these data are the first demonstration that INSL4 mRNA are translated into pro-EPIL and EPIL peptides.

The gene mutated in X-linked adrenoleukodystrophy (ALD), a progressive demyelinating disease, codes for a protein (ALDP) involved in very-long-chain fatty acid (VLCFA) transport. The expression of ALDP and of two peroxisomal enzymes involved in beta-oxidation of VLCFA, acyl-CoA oxidase, and catalase was studied in human and mouse brain. The pattern of expression was similar in both species. While acyl-CoA oxidase and catalase are found in all types of CNS cells, including neurons and oligodendrocytes, ALDP expression is restricted mostly to the white matter and endothelial cells. ALDP is highly expressed in astrocytes and microglial cells in vivo and in regenerating oligodendrocytes in vitro. In contrast, in vivo, ALDP is detected in much fewer oligodendrocytes and quantitative Western blot analysis confirmed the lower abundance of ALDP in these cells than in astrocytes. Only oligodendrocytes localized in corpus callosum, internal capsules, and anterior commissure express ALDP at levels comparable to those seen in astrocytes. In ALD, demyelination is first detected in these white matter regions, suggesting that the ALD gene mutation selectively affects those oligodendrocytes strongly expressing ALDP. Because of their failure to express ALDP, microglia and astrocytes may also contribute to demyelination in ALD patients.

ContextThyroglobulin (Tg) measurement is a major tool for the follow-up of differentiated thyroid cancer (DTC) patients; however, in patients who do not undergo radioactive iodine (RAI) ablation, normal ultrasensitive Tg levels measured under levothyroxine treatment (usTg/l-T4) are not well defined.Objective and designThis single-center retrospective study assessed usTg/l-T4 level in 86 consecutive patients treated with total thyroidectomy without RAI ablation for low-risk DTC (n=77) or for tumors of uncertain malignant potential (TUMP) (n=9).ResultsDTCs were classified as pT1, pT2, and pT3 in 75, 1, and 1 case respectively and pN0, pN1, and pNx in 40, 6, and 31 respectively. Following surgery, ten patients had Tg antibodies (TgAb). Among those without TgAb, the first usTg/l-T4 determination obtained at a mean time of 9 months after surgery was ≤0.1 ng/ml in 62% of cases, ≤0.3 ng/ml in 82% of cases, ≤1 ng/ml in 91%, and ≤2 ng/ml in 96% of cases. After a median follow-up of 2.5 years (range: 0.6–7.2 years), one patient had persistent disease with an usTg/l-T4 at 11 ng/ml and an abnormal neck ultrasonography (US) and two patients had usTg/l-T4 level >2 ng/ml (3.9 and 4.9 ng/ml) with a normal neck US. Within the first 2 years following total thyroidectomy without RAI ablation, usTg/l-T4 level is ≤2 ng/ml in 96% of the cases.ConclusionAfter total thyroidectomy, sensitive serum Tg/l-T4 level is ≤2 ng/ml in most patients and can be used for patient follow-up.

Results are presented on a peptide fragment (1013-1056) from human DNA topoisomerase II alpha. This was selected using the procedure of Lupas et al. (Lupas, A., Van Dyke, M., and Stock, J. (1991) Science 252, 1162-1164) for its potential to adopt a stable coiled-coil structure. The same theoretical treatment rejected the segment 994-1021 proposed by Zwelling and Perry (Zwelling, L. A., and Perry, W. M. (1989) Mol. Endocrinol. 3, 603-604) as a possible core for leucine-zipper formation. Our experimental studies combine cross-linking and CD analysis. Cross-linking establishes that the 1013-1056 fragment forms a stable homodimer in solution. Effects of increasing peptide concentration on CD spectra confirm that only the 1013-1056 fragment can undergo a coiled-coil stabilization from an isolated alpha-helix. Unfolding experiments further show that the coiled-coil is more stable in guanidium chloride than in urea. Values of -6.8 and -7.4 kcal/mol for the dimerization free energy are determined by thermal and urea unfolding, respectively. These are strikingly similar to the value recently found for the dissociation/reassociation of the entire yeast topoisomerase II from sedimentation equilibrium experiments (Lamhasni, S., Larsen, A. K., Barray, M., Monnot, M., Delain, E., and Fermandjian, S. (1995) Biochemistry 34, 3632-3639), although their significance relatively to topoisomerase II undoubtedly requires further analysis.

Ovarian yolk sac tumour (OYST) is a very rare malignancy arising most often in young women. Preoperative clinical, biological (alpha-foetoprotein) and radiological findings should help to establish the diagnosis of OYST, in order to propose adequate surgical treatment. The aim of surgery is to remove the primary tumour, to obtain an accurate histological diagnosis and to assess the disease extent. In young women, fertility-sparing surgery should be performed, in order to preserve the possibility of pregnancy later on. Chemotherapy has substantially modified the prognosis of these tumours, and practically all patients will be cured. The overall 5-year survival rate is 94% when patients are treated with BEP chemotherapy. Depending on the clinical situation, two to four cycles of the BEP regimen should be administered after surgery. Identification of prognostic factors may help to propose risk-adapted treatment in order to increase the cure rate in patients with a poor prognosis and to decrease toxicity in patients with a low risk of relapse. Fertility preservation represents a major objective in women treated for OYSTs.

The equine (e) placental glycoprotein hormone eCG plays a critical though not completely understood role during the first trimester of gestation in mares. In the present work, we have developed immunoradiometric assays (m-IRMAs) for detection of eCG, eCG alpha, and eCG beta using combinations of monoclonal antibodies (mAbs) specific for epitopes that reside on free and/or combined subunits. The free eCG alpha m-IRMA was based on AHT20 mAb, specific for the free alpha-subunit of all species, and 125I-labeled ECG01 mAb, which recognizes both free and combined alpha-subunit from equine and primate species. The free eCG beta was measured by the combination of FBT11 mAb, which binds to free beta-subunit from human and equine species, and radiolabeled 518B7 mAb, which detects CG/LH from diverse mammalian species. This assay provided a better sensitivity for eLH beta than for eCG beta. However, after treatment with neuraminidase, the latter molecule was recognized as well as eLH beta, indicating that the carbohydrate structure influenced the binding of mAbs. Detection of eCG was based on the combination of ECG01 mAb (anti-alpha) as capture antibody and 125I-labeled 518B7 mAb (anti-beta). Using such assays, we measured plasma and urinary concentrations of both eCG and free subunits in pregnant mares from mating to day 90 of gestation. eCG was constantly detectable in the serum between days 40-90, as previously reported, but small amounts of the dimeric hormone in the urine were also detectable. Further, m-IRMA specific for the free beta-subunit showed that low levels (5-100 ng/ml) of eCG beta may coexist with eCG in serum and urine during early pregnancy in mares. In contrast, free eCG alpha subunit was undetectable during the first 10 weeks of gestation. These results suggested that eCG and free subunit production in pregnant mares at the beginning of gestation is similar to that observed in pregnant women. These immunoassays, specific for either intact hormone or its free subunits, constitute useful diagnostic tools for investigating reproductive problems in mares.

Background Ovarian yolk sac tumor (YST) is a very rare malignancy arising in young women. Chemotherapy has dramatically improved the prognosis. Current treatment consists of surgery followed by bleomycin, etoposide, and cisplatin (BEP) chemotherapy. However, given the rarity of this tumor, ovarian YST-specific survival and outcome after such treatment are not precisely known. Patients and methods This report concerns prospectively recorded cases that were either treated at Institut Gustave Roussy (Villejuif, France) or referred there for advice about therapy. From 1990 to 2006, 52 patients underwent surgery followed by BEP chemotherapy. Data on patient characteristics, treatment, survival, and fertility outcome were analyzed to assess treatment efficacy and gonadal toxicity after achieving a complete remission. Results Thirty-five patients had stage I/II tumors while 17 patients presented with stage III/IV disease. With a median follow-up of 68 months, the overall 5-year survival and disease-free survival rates were 94% and 90%, respectively. Forty-one women underwent fertility-sparing surgery. Pregnancy was achieved in 12 of 16 (75%) women who attempted conception. Overall, 19 pregnancies have been recorded. Conclusions BEP chemotherapy following fertility-sparing surgery is a very effective treatment of ovarian YSTs. Most of the patients who attempt conception after complete remission will have children.

ObjectiveThe progression of medullary thyroid cancer is difficult to assess with imaging modalities; we studied the interest of calcitonin and carcinoembryonic antigen (CEA) doubling times and of Ki-67 labeling and mitotic index (MI).Patients and methodsFifty-five consecutive medullary thyroid carcinoma (MTC) patients with elevated calcitonin levels underwent repeated imaging studies in order to assess tumor burden and progression status. We looked for relationships between tumor burden and levels of calcitonin and CEA and between progression status according to the response evaluation criteria in solid tumors (RECIST) and calcitonin and CEA doubling times, and Ki-67 labeling and MI.ResultsThe calcitonin and CEA levels were correlated with tumor burden. Ten patients with calcitonin levels below 816 pg/ml had no imaged tumor foci. Among the 45 patients with imaged tumor foci, 19 had stable disease and 26 had progressive disease, according to the RECIST. The calcitonin and CEA doubling times were strongly related to disease progression, with very few overlaps: 94% of patients with doubling times shorter than 25 months had progressive disease and 86% of patients with doubling times longer than 24 months had stable disease. Ki-67 labeling and MI were not significantly associated with disease progression.ConclusionFor MTC patients, the doubling times of both calcitonin and CEA are efficient tools for assessing tumor progression.

Cancer antigen CA125 is known as a valuable marker for the management of ovarian cancer.The analytical and clinical performance of the Access OV Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA125 on the Elecsys System (Roche Diagnostics).Total imprecision (% CV) of the OV Monitor ranged between 3.1% and 8.8%, and inter-laboratory reproducibility between 4.7% and 5.0%. Linearity upon dilution showed a mean recovery of 100% (SD + 8.1%). Endogenous interferents had no influence on OV Monitor levels (mean recoveries: hemoglobin 107%, bilirubin 103%, triglycerides 103%). There was no high-dose hook effect up to 27,193 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access OV Monitor and Elecsys CA125 (R = 0.982, slope = 0.921, intercept = +1.951). OV Monitor serum levels were low in healthy individuals (n = 267, median = 9.7 kU/L, 95th percentile = 30.8 kU/L), higher in individuals with various benign diseases (n = 549, medians = 10.9-16.4 kU/L, 95th percentiles = 44.2-355 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 12.4-445 kU/L; 95th percentiles = 53.4-4664 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the OV Monitor was found for ovarian cancer [area under the curve (AUC) 0.898]. Results for the reference CA125 assay were comparable (AUC 0.899).The Access OV Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with Elecsys CA125. The best diagnostic accuracy for the OV Monitor was found in ovarian cancer. Our results also suggest a clinical value of the OV Monitor in other cancers.

Background: Cancer antigen CA15-3 antigen is known as a valuable marker for the management of breast cancer. Methods: The analytical and clinical performance of the Access' BR Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA15-3 on the Elecsys(R) System (Roche Diagnostics). Results: Total imprecision (%CV) of the BR Monitor ranged between 5.5% and 11.7%, and inter-laboratory reproducibility between 3.4% and 5.1%. Linearity upon dilution showed a mean recovery of 98.5% (SD+/-9.1%). Endogenous interferents had no influence on BR Monitor levels (mean recoveries: hemoglobin 112%, bilirubin 111%, triglycerides 108%). There was no high-dose hook effect up to 13,540 kU/L. Clinical performance investigated in sera from 1811 individuals showed a general correlation between the Access BR Monitor and Elecsys CA15-3 (R = 0.797), with a slope of 1.383. CA15-3 serum levels, as measured by the BR Monitor, were low in healthy individuals (n = 267, median = 11.9 kU/L, 95th percentile = 23.5 kU/L), higher in individuals with various benign diseases (n = 549, medians = 11.3-15.6 kU/L, 95th percentiles = 21.6-54.6 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 11.2-22.8 kU/L, 95th percentiles = 30.0-429.7 kU/L). Best diagnostic accuracy for cancer detection against the relevant benign control group by the BR Monitor was found for locoregional and metastatic breast cancer, as well as for ovarian cancer {[}area under the curve (AUC) 0.619, 0.897 and 0.774]. Results for the reference CA15-3 assay were comparable (AUC 0.611, 0.887 and 0.818). Conclusions: The Access BR Monitor provides accurate methodological characteristics and demonstrates an analytical and clinical correlation with Elecsys CA15-3. Best diagnostic accuracy for the BR Monitor was found in breast and ovarian cancer. Our results also suggest a clinical value of the BR Monitor in other cancers.

Antibodies were elicited against a synthetic peptide which encompassed two different regions of the human lutropin beta-subunit (hLH-beta). These antibodies were raised against either the peptide which was assembled using a conventional approach and conjugated to the tetanus toxoid, or with the peptide assembled using the multiple antigen peptide system approach. Automated simultaneous synthesis of the two forms of the immunizing peptide was successfully achieved. Animal injected with the peptide conjugated to tetanus toxoid produced high titers of antibodies to the synthetic peptide, but did not bind to the native hLH-beta subunit. In contrast, antisera induced by the peptide in its MAP form displayed reactivity with both the peptide and the native hLH-beta subunit; these latter antisera appeared to preferentially recognize the beta 47-55 portion of the molecule and were able to bind to the beta-subunit of human choriogonadotropin. Present results demonstrate that the beta 47-55 region is accessible to antibody binding and appears to be located at the surface of both hLH-beta and hLH. Moreover, this study confirms that the MAP approach provides a chemically unambiguous method for obtaining antibodies of predetermined specificity, capable of recognizing cognate sequences of various native proteins.

In an attempt to further study various fragments of free and combined forms of hCG beta present in biological fluids, we performed one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by Western immunoblotting using antipeptide antibodies directed to the hCG beta-(111-116) portion (monoclonal antibody FB12) antiserum to the hCG beta(8-16) portion or antiserum which was specific for fragments ending at residue 47. Results observed in a crude preparation of urinary hCG demonstrated that in addition to the carboxyl-terminal part of the reduced hCG beta nicked subunit (beta NS) [hCG beta-(48-145)], three other fragments of mol wt 18,000 (F1), 16,500 (F2), and 12,000 (F3) were detectable after cleavage of disulfide bonds. Both the immunoreactivity pattern and peptide sequencing revealed that the F1 fragment was constituted of the hCG beta-(1-47) sequence, whereas the F2 fragment comprised the 6-47 portion. We then studied the beta NS in urine from either pregnant women or four patients with choriocarcinomas. Results showed that both hCG and the free beta-subunit contained beta NS. Furthermore, free hCG beta present in those urine samples appeared to be extensively, if not totally, nicked. Results observed in urine were confirmed using separation of hCG from its beta-subunit by a two-step chromatography procedure, identification of hCG and hCG beta immunoreactive peaks by specific monoclonal immunoradiometric assay, and analysis of resulting preparations by one-dimensional electrophoresis under reducing conditions, followed by Western immunoblotting with FB12. This latter protocol was also used to investigate the presence of beta NS in sera of four patients with choriocarcinoma tumors. In those sera, hCG appeared to be nicked. This study demonstrates that the beta-subunit of hCG is modified by multiple fragmentations.

Background: Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease. Aim: The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation. Methods: Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9–12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up. Results: Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19–40% and 68–76% and specificity ranged from 92–97% and 81–91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2–0.3 ng/ml, sensitivity was 54–63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85–87% for Tg1. Conclusion: Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient’s reassurance.

International audience; The eukaryotic topoisomerase II is an ubiquitous nuclear enzyme involved in vital cellular functions. It is also the target for some of the most active anticancer drugs. In the various crystal structures of yeast topoisomerase II, the 701-748 segment homologous to the human topoisomerase II alpha 724-771 segment folds into a compact alpha(2)beta(1)alpha(3)talpha(4) conformation, hereafter termed alpha(2)HTH module (helix turn helix (HTH), alpha(3)talpha(4)). The crystal structure of gyrase A has suggested a model wherein HTH is involved in both the enzyme dimerization and the binding to DNA. These two properties were investigated in solution, using the recombinant alpha(2)HTH module of human topoisomerase II alpha and its synthetic components HTH, alpha(4), alpha(3) and turn. The homology-based structure model of human alpha(2)HTH superposed that of yeast in the crystal structure with a rmsd of 1.03 A. Circular dichroism spectra showed that the helical content of human alpha(2)HTH in solution is similar to that of its counterpart within yeast topoisomerase II in the solid state. The chemical cross-linking data indicated that alpha(2)HTH self-associated into dimers while gel mobility shift assays and anisotropy fluorescence titrations demonstrated that alpha(2)HTH, HTH and alpha(4), but not alpha(3), bind efficiently to DNA (dissociation constants of 3.10(-7) M for alpha(2)HTH and alpha(4), of 3.10(-6) M for HTH and of only 1.10(-5) M for alpha(3)). Correlatively, alpha(2)HTH, alpha(4) and HTH, but not alpha(3), were able to inhibit topoisomerase II in DNA relaxation assays, stipulating that alpha(4) is the DNA recognition helix. All suggests that the alpha(2)HTH module once separated from the whole protein conserves a compact conformation, integral to specific dimerization and DNA recognition. The module may thus be used for the search of drugs efficient in hindering topoisomerase II dimerization or binding to DNA.

International audience; The HIV-1 integrase (IN) catalyzes the integration of viral DNA in the human genome. In vitro the enzyme displays an equilibrium of monomers, dimers, tetramers and larger oligomers. However, its functional oligomeric form in vivo is not known. We report a study of the auto-associative properties of three peptides denoted K156, E156 and E159. These derive from the alpha4 helix of the IN catalytic core. The alpha4 helix is an amphipatic helix exposed at the surface of the protein and could be involved in the oligomerization process through its hydrophobic face. The peptides were obtained from the replacement of several amino acid residues by more helicogenic ones in the alpha4 helix peptide. K156 carries the basic residues Lys156 and Lys159, which have been shown important for the binding of IN to viral DNA. In E156 and E159 they are replaced with the acidic residue Glu. A fourth peptide K(E)156 obtained from the replacement of hydrophobic residues with Glu in K156 in order to abolish the auto-associative properties is used as a negative control. The capacity shown by peptides for alpha-helical formation is demonstrated by circular dichroism (CD) analysis performed in aqueous solution and in aqueous trifluoroethanol (TFE) mixtures. Both electrospray ionization mass spectrometry (ESI-MS) and glutaraldehyde chemical cross-linking show that peptides adopt different solvent-dependent equilibriums of monomers, dimers, trimers and tetramers. Oligomerization of peptides in aqueous solution is related to their ability to form helical structures. Addition of a small amount of TFE (

International audience; The peptide denoted K159 (30 residues) derives from the catalytic core (CC) sequence of HIV-1 integrase (IN, residues 147-175). In the crystal structure of CC, the corresponding segment belongs to the alpha4 helix (residues 148-168, including residues Glu 152, Lys 156 and Lys 159, crucial for enzyme activity and DNA recognition), a loop (residues 169-171) and a part of the alpha5 helix (171-175), involved in enzyme dimerization. We used the fluorescence and the circular dichroism (CD) properties in the near-UV of the aromatic side chain of a tyrosine residue added at the C-terminal end of K159 in order to analyze the behavior of the concentrated and diluted peptide in aqueous trifluoroethanol (TFE), in an attempt to connect the information obtainable at high (NMR), medium (CD) and low (fluorescence) concentrations of the peptide. Altogether, the C-terminal tyrosine residue provided indirect information on the global conformation of K159 and on the local orientation and environment of the residue. The propensity of TFE to stabilize alpha-helical conformations in peptides was confirmed in CD and fluorescence experiments at relatively high (20-160 microM) and low (2-16 microM) concentrations, respectively. At relatively high concentration, stabilization of the peptide into alpha-helical conformation favored its auto-association likely in parallel coiled-coil dimers, as pointed out in our previous work [Eur. J. Biochem. 253 (1998) 236]. This was further confirmed by ANS (1-anilinonaphtalene-8-sulfonic acid) analysis and fluorescence temperature coefficient measurement. With diluted K159, a Stern-Volmer analysis with positively and negatively charged quenchers indicated that, when the intermolecular interactions were absent, the tyrosine was in a positively charged environment, as if the peptide folded into a U-shaped conformation similar to that present in the crystal structure of the enzyme.

International audience; The last decade has contributed to our understanding of the three-dimensional structure of the human immunodeficiency virus, type 1 (HIV-1) integrase (IN) and to the description of how the enzyme catalyzes the viral DNA integration into the host DNA. Recognition of the viral DNA termini by IN is sequence-specific, and that of the host DNA does not require particular sequence, although in physicochemical studies IN fails to discriminate between the two interactions. Here, such discrimination was allowed thanks to a model system using designed oligonucleotides and peptides as binding structures. Spectroscopic (circular dichroism, NMR, and fluorescence anisotropy) techniques and biochemical (enzymatic and filter binding) assays clearly indicated that the amphipathic helix alpha4, located at the catalytic domain surface, is responsible for the specific high affinity binding of the enzyme to viral DNA. Analogues of the alpha4 peptide having increased helicity and still bearing the biologically relevant lysines 156 and 159 on the DNA binding face, and oligonucleotides conserving an intact attachment site, are required to achieve high affinity complexes (Kd of 1.5 nm). Data corroborate previous in vivo results obtained with mutated viruses.

The aim of the present study was to evaluate the clinical performance of the CA 15-3 assay on Elecsys systems in an international multicenter study (11 centers). A total of 1326 single samples (272 apparently healthy individuals, 34 pregnant women, 308 benign diseases, 273 cancers other than breast, 439 breast cancer) and 538 serial samples of 98 breast cancer patients during follow-up were analyzed. 95% of values in healthy individuals were below 25 kU/L, and 88% in benign breast diseases, respectively. In malignant breast disease at primary diagnosis the value distribution of Elecsys CA 15-3, sensitivity at 95% specificity, as well as the areas under the curve in ROC analysis were clearly correlated to tumor stages: UICC I to IV 88 to 25% of values25 kU/L, sensitivity 7 to 78%, areas under the curve 0.53 to 0.94. During follow-up, sensitivity/specificity for detection of recurrences were 90%/71%. In metastatic disease clinical progression/response to therapy were indicated in 91%/78% of patients at a specificity of 92%/78%. The findings indicate that the Elecsys CA 15-3 assay is very suitable in routine work for detection of recurrences as well as for therapy control in metastatic breast cancer.

Although the sensitivity and specificity of CA 15-3 in primary diagnosis of breast cancer is limited, CA 15-3 measurement has found widespread use in monitoring disease progression and response to therapy [reviewed in Ref. (1)]. A new assay for determination of CA 15-3 on Elecsys® immunoanalyzers has been introduced by Roche Diagnostics GmbH. The analytical performance of this assay was tested in an international multicenter evaluation in 11 evaluation sites, and the clinical performance was judged in 4 of these laboratories. The results are described in this report. Elecsys CA 15-3 is a sandwich immunoassay that uses biotinylated 115D8 and ruthenylated DF3 as capture and detection antibodies, respectively, and electrochemiluminescence as the detection technology. Details of the test principle have been described previously (2). The test is standardized against the Enzymun-Test CA 15-3 (Roche Diagnostics GmbH) in the laboratories of the manufacturer. The analytical evaluation was carried out according to a standardized protocol of the European Committee for Clinical Laboratory Standards (3). The results of within-run imprecision (21 replicates per analysis) and between-day imprecision (1 replicate analyzed on 21 different days) studies are available as a data supplement at Clinical Chemistry Online (http://www.clinchem.org/content/vol47/issue12). The medians of the within-run and between-day CVs were 2.5–3.8% and 5.0–5.9%, respectively, at all concentrations tested (8.4–251.7 kilounits/L) for human sera and control sera. Confirmation of target values assigned to control sera was tested in an interlaboratory survey and was 97% for PreciControl Tumor Marker Level 1 (18.4 kilounits/L) and 96% for Level 2 (58.6 kilounits/L). The medians of all participants of an interlaboratory survey of the German Society for Clinical Chemistry were confirmed for each of the two control samples used (11.8 and 16.8 kilounits/L) by 99% (on the basis of the medians of all participants in the Elecsys study); thereby demonstrating the excellent agreement …

International audience; Integration of HIV-1 genome into host cell chromosome is mediated by viral integrase (IN). The IN catalytic core (CC, IN(50-212)) dimerizes through mutual interactions of its alpha1 and alpha5 helices. Peptides INH1 and INH5 reproducing these helix sequences strongly inhibited IN. For instance, an IC(50) of 80 nM was determined for INH5 in integration assays using wild-type IN (wtIN). In size exclusion chromatography, INH1 and INH5 perturbed the association-dissociation equilibrium of both dmIN (IN(1-288)/F185K/C280S) and CC, leading to monomers as surviving species, while in circular dichroism, binding of peptides to dmIN altered the protein conformation. Thus, enzyme deactivation, subunit dissociation, and protein unfolding are events which parallel one another. The target of INH5 in the enzyme was then identified. In fluorescence spectroscopy, C(0.5) values of 168 and 44 nM were determined for the binding affinity of INH5 to IN and CC, respectively, at 115 nM subunit concentration, while interaction of INH5 with INH1 was found stronger than interaction of INH5 with itself (23 times larger in term of dissociation constants). These results strongly suggested that the alpha1 helix is the privileged target of INH5. The latter could serve as a lead for the development of new chemotherapeutic agents against HIV-1.

In testis, several RNA binding proteins have been shown to play a role in the translational regulation of specific transcripts. The human protein TRBP (TAR RNA binding protein) is the homologue of the mouse Prbp (Prm-1 RNA binding protein) involved in the protamine mRNA translational delay. TRBP is known to activate the HIV-1 long terminal repeat but this protein has never been investigated during spermatogenesis. The aim of this work was to analyse the TRBP expression in human testis. By Northern blot analysis, we demonstrated a major 1.5 kb transcript present at a high level in human testis and, to a lesser extent, in some other tissues. In-situ hybridization revealed that this transcript was present only in elongating spermatids. Antibodies raised against a 27 amino acid TRBP-specific peptide revealed a single protein of 43 kDa expressed in the cytoplasm of elongated spermatids. At the ultrastructural level, quantitative analysis of both TRBP mRNA and protein, using electron microscopy in-situ hybridization and immunocytochemistry, showed that TRBP is expressed mainly in spermatids at steps 3-4 of spermiogenesis. These results are in agreement with the probable role of TRBP in the control of human protamine mRNA translation.

Monospecific antibodies were raised against a synthetic peptide K159 (SQGVVESMNKELKKIIGQVRDQAEH-LKTA) reproducing the segment 147–175 of HIV-1 integrase (IN). Synthesis of substituted and truncated analogs ofK159 led us to identify the functional epitope reacting with antibodies within the C-terminal portion 163–175 ofK159. Conformational studies combining secondary structure predictions, CD and NMR spectroscopy together withELISA assays, showed that the greater is the propensity of the epitope for helix formation the higher is therecognition by anti-K159. Both the antibodies and the antigenic peptide K159 exhibited inhibitory activities againstIN. In contrast, neither P159, a Pro-containing analog of K159 that presents a kink around proline but with intactepitope conformation, nor the truncated analogs encompassing the epitope, were inhibitors of IN. While the activityof antibodies is restricted to recognition of the sole epitope portion, that of the antigenic K159 likely requiresinteractions of the peptide with the whole 147–175 segment in the protein [Sourgen F., Maroun, R.G., Fre`re, V.,Bouziane, A., Auclair, C., Troalen, F. & Fermandjian, S. (1996) Eur. J. Biochem. 240, 765–773]. Actually, of alltested peptides only K159 was found to fulfill conditions of minimal number of helical heptads to achieve theformation of a stable coiled-coil structure with the IN 147–175 segment. The binding of antibodies and of theantigenic peptide to this segment of IN hampers the binding of IN to its DNA substrates in filter-binding assays. Thisappears to be the main effect leading to inhibition of integration. Quantitative analysis of filter-binding assay curvesindicates that two antibody molecules react with IN implying that the enzyme is dimeric within these experimentalconditions. Together, present data provide an insight into the structure–function relationship for the 147–175peptide domain of the enzyme. They also strongly suggest that the functional enzyme is dimeric. Results could helpto assess models for binding of peptide fragments to IN and to develop stronger inhibitors. Moreover, K159antibodies when expressed in vivo might exhibit useful inhibitory properties.Keywords: antibodies, conformational aspects, HIV integrase, inhibition, peptides.The human immunodeficiency virus (HIV) replication cycle isinitiated by integration of the viral DNA into the cell genome[1,2]. Integrase (IN) [2–4] encoded by the virus pol genecatalyses integration sequentially through the deletion of twonucleotides at the conserved 3

Triplex-forming oligonucleotides (TFOs) are generally designed to inhibit transcription or DNA replication but can be used for more diverse purposes. Here we have designed a chimera peptide-TFO able to activate transcription from a target gene. The designed hybrid molecule contains a triplex-forming sequence, linked through a phosphoroamidate bond to several minimal transcriptional activation domains derived from Herpes simplex virus protein 16 (VP16). We show here that this TFO-peptide chimera (TFO-P) can specifically recognise its DNA target at physiological salt and pH conditions. Bound to the double-stranded target DNA in a promoter region, the TFO-P is able to activate gene expression. Our results suggest that this type of molecule may prove useful in the design of new tools for artificial modulation of gene expression.

Human immunodeficiency virus type 1 integrase (HIV-1 IN) which catalyzes viral DNA integration into the host genome of infected cells represents an attractive target for AIDS therapy. We have previously demonstrated the ability of the IN-(147-175)-peptide derived from the catalytic core domain of HIV-1 IN to inhibit the enzyme activity in vitro. IN-(147-175)-peptide contains four heptad repeats and displays a high propensity for coiled-coil formation while its [P159]IN-(147-175)-peptide analog (Lys159-->Pro in the protein, Lys13-->Pro in the peptide) is unable to form a stable coiled-coil and is devoid of inhibitory activity [Sourgen, F., Maroun, R. G., Frere, V., Bouziane, M., Auclair, C., Troalen, F. & Fermandjian, S. (1996) Eur. J. Biochem. 240, 765-773]. Now, we report results from an NMR study on IN-(147-175)-peptide and [P159]IN-(147- 175)-peptide as well as on an optimized [E156, A163, A167]IN-(147-175)-peptide that is a better inhibitor of IN than IN-(147-175)-peptide. While in aqueous solution, IN-(147-175)-peptide and [P159]IN-(147-175)-peptide display only nascent helical features, [E156, A163, A167]IN-(147-175)-peptide exhibits 20% of helical content. In 20% trifluoroethanol/80% H2O, the helix content is the highest for [E156, A163, A167]IN-(147-175)-peptide (approximately 70%) and the lowest for [P159]IN-(147-175)-peptide (approximately 40%), due to a local helix break caused by the Pro residue. The NHs of residues in the two central helical heptads (a-g) of IN-(147-175)-peptide and [E156, A163, A167]IN-(147-175)-peptide display a regular periodic variation of their temperature coefficients in 20% trifluoroethanol. The b, c and f residues on the hydrophilic face of the amphipathic helix show high coefficients reflecting hydrogen bonded NHs, while the a and d residues on the hydrophobic face exhibit low coefficients, near random-coil values. The particular arrangement of the hydrophobic side-chains of a and d residues at the coiled-coil interface reduces the access of trifluoroethanol molecules to their amide groups. The inability of trifluoroethanol molecules to create interactions with the amide C=O groups, these being required to strengthen the intrahelical C=O...H-N hydrogen bonds, is the main cause for observation of heptadic a and d residues with low NH temperature coefficients. Such effects concern mostly the two central helical heptads of IN-(147-175)-peptide and [E156, A163, A167]IN-(147-175)-peptide implying that these ones are engaged in stable parallel coiled coils. Our results provide a link between the propensity of peptides for helix formation, their coiled-coil properties and their efficiency to inhibit IN.