[Is there a place for stepped hormone assay in the development of hyperandrogenism?]

Clinical hyperandrogenism is common in women. Nevertheless, it is important to identify the cause. As the hyperandrogenism may be ovarian or adrenal in origin, making the difference requires hormonal testing and ovarian and/or adrenal imaging. We present the case report of a patient explored in our clinic, that illustrates the difficulties to determine the origin of the endocrine disorder. The interest of employing selective ovarian and adrenal venous catheterization to aid in the diagnosis and the localization of the androgen-secreting tumor is discussed.

[Biopsy of suspicious lesions in patients with breast cancer]

Discordances between hormone receptors and HER2 status in primary and metastatic breast cancer have been reported by several studies. In this context, systematic biopsies could be clinically relevant in breast cancer to confirm the biological characteristics of a suspicious lesion. In this article, illustrated by 2 case reports and based on a recent review on this topic, we discuss the clinical significance of receptor discordances and possible diagnosis of a secondary primary tumor. The role of these biopsies for the identification of new therapeutic targets is also envisaged as well as underlying mechanisms for receptors' modification like tumoral heterogeneity, clonal selection and technical artifacts.

Re-biopsy in breast cancer recurrence: Is there really a clinical impact?

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Background: Several retrospective studies and 3 prospective studies have shown discordance in receptor status between primary tumor and metastasis leading to a treatment modification in about one out of 7 patients. However, some clinicians report unpublished data suggesting that these findings are not observed in all centers. We did prospectively a biopsy at suspicion of first relapse in our center and evaluated the impact of this biopsy on the management of our patients. Methods: Thirty four patients underwent a biopsy between October 2011 and January 2013. Hormonal receptor status was determined by the same IHC methodology for primary and metastatic tissue. Primary tumors were reanalyzed if necessary with our current IHC technique. A change in ER or PgR status was considered clinically significant if quantitative staining changed from <5 % to at least 10% of tumor cells expressing the hormonal receptor or if the opposite is observed. We tested HER2 status by IHC and/or FISH: HER2 3+ or 2+ and FISH positive cases were considered as HER2 positive. Results: Three of 34 patients were considered as screening failure. 1/31 (3.2 %) biopsies showed a benign disease, 2/31 (6.4 %) were non contributive and 5/31 (16 %) showed a metastasis of a second primary tumor. Two of these findings were totally unexpected according to clinical data. Changes in hormone receptor status were observed in 25 % but no change in HER2 status was observed. Time to recurrence was not significantly different between groups with or without modified hormonal status. No clinically significant complication was observed following the biopsies. Only patients presenting a second primary tumor had their management changed based on the new biopsy. Conclusions: We found discordance in hormone receptor status (25 %) but it did not change the treatment. Our study confirms the importance of re-biopsy in order to exclude benign disease or to find metastasis from an unknown and sometimes unexpected second primary tumor. Although our study does neither confirm changes in hormonal receptors resulting in the modification of the treatment strategy nor a change in HER2 status, our data suggest that a new biopsy at first relapse should be performed because unexpected second primaries can be discovered.

A novel heterodimeric transferrin receptor encoded by a pair of VSG expression site-associated genes in T. brucei

In T. brucei, a transferrin-binding protein has been found to share sequence homology with pESAG-7 and -6, the products of two related genes present in the VSG gene polycistronic transcription unit. When expressed in Xenopus oocytes, they appear as N-glycosylated proteins secreted in the medium (pESAG-7) and GPI anchored to the membrane (pESAG-6). These proteins are able to homo- or heterodimerize, probably through association in the same orientation. Only heterodimers can bind Tf, possibly two molecules per dimer. A comparison of Tf binding to pESAG-7/6-expressing oocytes and trypanosomes suggests that pESAG-7/6 is the Tf receptor of the parasite. In trypanosomes, the majority of pESAG-7/6 is released from the membrane and associates, together with Tf, with a glycosylated matrix present in the lumen of the flagellar pocket. Both pESAG-7/6 and Tf are internalized via coated pits and vesicles. These observations suggest a novel mode of Tf binding and uptake in trypanosomes.

Abrupt RNA changes precede the first cell division during the differentiation of Trypanosoma brucei bloodstream forms into procyclic forms in vitro

We have monitored the timing of DNA and RNA synthesis during the synchronous differentiation of Trypanosoma brucei bloodstream forms into procyclic forms in vitro. Both are triggered after a lag period of 4 h and reach a first peak after 9 h. The division of the kinetoplast precedes that of the nucleus by about 4 h. The first cell divisions are observed after 10 h, and the cell number is doubled after 20 h. The total RNA content per cell increases sharply between 4 and 10 h, then progressively decreases as cell division progresses. The increase in RNA content cannot be due solely to accumulation of rRNA since it is also observed for mRNAs such as actin. The VSG mRNA has almost disappeared within 2 h, while the procyclin mRNA accumulates soon after the triggering of differentiation, with a strong peak between 4 and 6 h. At this moment, the amount of procyclin mRNA per cell is at least 20-fold higher than in established procyclic culture forms. The loss of the VSG and the appearance of procyclic-specific proteins essentially occur before the first cell division. These observations contrast with the progressive transition observed when monomorphic slender forms are induced to transform under the same conditions.

Transient adenylate cyclase activation accompanies differentiation of Trypanosoma brucei from bloodstream to procyclic forms

Pleomorphic bloodstream forms of Trypanosoma brucei differentiate synchronously into procyclic forms when cultivated at 27 degrees C in the presence of citrate/cis-aconitate. The activity of adenylate cyclase was monitored during this process. Two phases of transient stimulation were observed. The first phase occurred 6-10 h after the triggering of differentiation, a period which immediately follows the release of the bulk of the VSG and immediately precedes both the first cell division and the loss of the bloodstream-specific ESAG 4 transmembrane adenylate cyclase. The second phase occurred between 20 and 40 h, when the cells that emerged from the first division began to proliferate. These observations suggest that cAMP may be involved in differentiation/proliferation of the parasite.

Expression of ras-like proteins in embryonic and adult cells of Xenopus laevis

A polyclonal antibody raised against v-Ha-ras p21 was purified and its specificity was checked on Ha-ras transformed cell lines. It was used to immunoprecipitate p21 from different Xenopus laevis cell types: brain cells, blood cells, and embryonic material. By one-dimensional Western blot analysis, we show that ras p21 is synthesized very early in oogenesis and accumulates throughout vitellogenesis. The ras p21 content, estimated to be 1.1 ng in the full-grown oocyte, remains constant during oocyte maturation and egg cleavage. Increase in the amount of ras p21 occurs at the beginning of neurulation. Two-dimensional Western blot patterns reveal the presence of multiple molecular forms of p21 in all Xenopus cell types studied. The numerous resolved polypeptides were ascribed to the expression of at least two different ras genes. Furthermore, specific charge modifications of the ras polypeptides are observed in brain, blood, and embryonic cells. During oogenesis and early embryonic development, differences in two-dimensional patterns mainly concern variations in the relative amounts of the different polypeptides. The results are discussed in relation to the well documented synthesis activities of the growing oocyte and of the early developing embryo.

Presence of high molecular weight glycans on the surface of germ and embryonic cells of Xenopus laevis

Xenopus laevis male germ cells, fertilized eggs and gastrula cells were labelled with 3H labelled sodium borohydride reduction after galactose oxidase treatment. After pronase digestion, the bulk of the label is carried by high molecular weight glycans (greater than or equal to 6,000 D). The high molecular weight of these labelled glycans and their susceptibility to degradation by endo-beta-galactosidase suggest that they may be related to the polylactosaminoglycans.

Injection of an antibody against a p21 c-Ha-ras protein inhibits cleavage in axolotl eggs

The presence of a ras protein was demonstrated in cleaving axolotl eggs by selective immunoprecipitation with a polyclonal antibody against a peptide encoded by the c-Ha-ras oncogene, cellular homolog of the v-Ha-ras oncogene of Harvey rat sarcoma virus. Injection of this antibody into axolotl oocytes subjected to progesterone treatment does not prevent meiotic maturation. Injection of the same antibody into a blastomere of axolotl eggs at the 2- or 4-cell stage causes cleavage arrest in the descendants of the injected blastomere. Cytological observations of the injected eggs show, in the arrested blastomeres, enlarged nuclei always surrounded by an intact nuclear envelope and containing uncondensed chromatin. The possible role of ras protein in meiosis and mitosis is discussed.

Characterization of yolk DNA from Xenopus laevis oocytes ovulated in vitro

High molecular weight DNA was isolated from the yolk platelets of Xenopus laevis oocytes ovulated in vitro. Yolk DNA has the same buoyant density in CsCl gradients as mitochondrial and nuclear DNAs, and, like them, it is double-stranded. Yolk DNA behaves like nuclear DNA, and not like mitochondrial DNA, upon renaturation after denaturation. The molecules are always linear. Cytochemical and biochemical controls preclude the possibility that the yolk DNA might be contaminated by nuclear or mitochondrial DNA. We conclude that the yolk DNA is an endogenous component of the yolk platelets.