A novel method for purification of biologically active C-terminal fragment of human recombinant anti-mullerian hormone.

Anti-mullerian hormone (AMH) is one of the least studied members of transforming growth factor beta superfamily showing pro-apoptotic activity against cells positive for hormone type II receptor overexpressed by malignant cells in many cancer cases. Here, we propose an improved method for isolation of recombinant C-terminal AMH fragment (C-rAMH) to obtain homogeneous preparations of this protein with high biological activity. In contrast to our previously developed C-rAMH purification technology based on reversed-phase HPLC, the key stage of the new approach is hydrophobic interaction chromatography using Toyopearl Butyl-650S resin performed under more benign conditions. This modification of the previously developed method allowed highly purified C-rAMH to be obtained that is characterized by twice the specificity estimated as the ability to bind to the recombinant analog of AMH type II receptor and by significantly higher biological activity, that is, the ability to induce the death of target cells. Thus, we made the purification technology even more cost-effective and suitable for the production of drug forms based on C-rAMH.

Purification of human recombinant anti-mullerian hormone and its derivatives.

Anti-mullerian hormone (AMH) is a cytokine of transforming growth factor ß (TGF-ß) superfamily able to induce apoptosis in cells bearing specific AMH type II receptors (AMHRII). AMHRII is overexpressed in some malignant cells, so at present recombinant AMH (rAMH) is considered as a new candidate antineoplastic drug. The use of rAMH may be especially effective in case of such severe diseases as ovarian, prostate and breast cancer. However, the development of a new drug is hampered by the laboriousness of obtaining highly purified rAMH and by the lack of data about the pharmacological characteristics of rAMH derivatives. In this work, we obtained preparations of prohormone, half-cleaved rAMH and a C-terminal fragment of rAMH, which was confirmed by qualitative and quantitative analyses. To obtain rAMH and its derivatives we used a previously developed highly effective producer strain containing the optimized human AMH gene. The production process has been divided into several stages: (a) rAMH biosynthesis in the bioreactor; (b) culture media preparation; (c) purification of rAMH and its derivatives using immunoaffinity chromatography and reversed-phase HPLC; (d) identification of the purified proteins by immunoblotting and analytical reversed-phase HPLC; and (e) evaluation of the hormone forms activity. The obtained proteins may be used in preclinical trials and in vitro study of rAMH derivatives properties.

Anti-Mullerian hormone concentrations in individual follicular fluids within one stimulated IVF cycle resemble blood serum values.

PURPOSE: Anti-Mullerian hormone (AMH) is commonly known as the most potent marker for ovarian reserve due to its decline as female age increases. While serum AMH (sAMH) levels have been intensively investigated, there is less data regarding AMH concentrations in follicular fluid (FF), since FF has usually been designated as waste product during oocyte collection in assisted reproductive technologies. This pilot study investigated follicle AMH concentrations (fAMH) of several follicles per ovary, individually collected with the Steiner-Tan needle, and compared them to sAMH concentrations in women undergoing IVF treatment. We hypothesized that there is no difference of fAMH concentrations in individual follicles and that these concentrations resemble the sAMH value of the patient. METHODS: Patients were stimulated with a gonadotropin-releasing hormone antagonist ovarian hyperstimulation protocol. On the day of oocyte retrieval, serum samples and FF from all individual follicles from one stimulated IVF cycle were collected and individually analyzed for AMH concentrations. RESULTS: Intracyclic mean fAMH values (n follicle = 2-14) were significantly correlated to sAHM values (ρ = 0.85, p < 0.001) and showed a trend to be negatively associated with age (ρ = -0.43, p = 0.06). Mean intrapatient fAMH concentrations differed significantly (p < 0.001). Furthermore, significant correlations of sAMH with individual fAMH values of the first five follicles of each patient were observed. CONCLUSIONS: In conclusion, our results clearly showed that individual fAMH concentrations reflected sAMH values and that fAMH concentrations did not significantly differ within one patient. In future studies, it will be interesting to correlate individual fAMH values to the respective embryo development and overall pregnancy outcome in order to improve IVF treatments and to refrain from embryo overproduction.

What is the optimal threshold of serum Anti-Müllerian hormone (AMH) necessary for IVM treatments?

PURPOSE: To assesse circulating levels of Anti-Müllerian hormone (AMH) as a predictor of oocyte number and their potential to mature in vitro in both normo-ovulatory (NO) women and in women with Polycystic Ovary Syndrome (PCOS) undergoing in vitro maturation (IVM) treatments. METHODS: We prospectively studied NO women and women diagnosed with PCOS, (age range 21-39 years) underwent IVM treatments at our center. Serum AMH levels were quantified before each cycle and correlated to oocytes number, maturation and fertilization during in vitro maturation. RESULTS: 104 NO and 30 PCOS IVM cycles were followed with retrieval of a total of 672 and 491 oocytes, respectively. In NO women, the serum AMH level positively correlated with the number of oocytes retrieved, (R = 0.6; P <0.0001) the number of M2 oocytes at 24 and 48 h (R = 0.4; P <0.01; R = 0.26 p < 0.007, respectively) and with the total number of M2 oocytes (R = 0.47; P < 0.0001). In the PCOS group, the serum AMH level positively correlated only with the number of oocytes retrieved (R = 0.43; P <0.03). Receiver operating characteristic (ROC) analyses showed that a cutoff AMH level of 1.56 (ng/ml) could identify patients with 5 or more oocytes at OPU with a sensitivity of 83 % and a specificity of 75 %. An AMH level of 1.63 (ng/ml) was the threshold for 5 or more matured oocytes (sensitivity = 81 %, specificity = 53 %). CONCLUSIONS: Serum AMH may be used as a marker to identify candidates for IVM treatment in both NO and PCOS women.

Correlation between three assay systems for anti-Müllerian hormone (AMH) determination.

PURPOSE: Analysis of anti-Müllerian hormone (AMH) is becoming of recognized importance in reproductive medicine, but assays are not standardized. We have evaluated the correlation between the new Gen II ELISA kit (Beckman-Coutler) and the older ELISA kits by Immunotech (IOT) and Diagnostic Systems Laboratories (DSL). METHODS: A total of 56 archived serum samples from patients with subfertility or reproductive endocrine disorders were retrieved and assayed in duplicate using the three AMH ELISA kits . The samples covered a wide range of AMH concentrations (1.9 to 142.5 pmol/L). RESULTS: We observed good correlations between the new (AMH Gen II) and old AMH assay kits by IOT and DSL (R(2) = 0.971 and 0.930 respectively). The regression equations were AMH (Gen II) = 1.353 × AMH (IOT) + 0.051 and AMH (Gen II) = 1.223 × AMH (DSL) - 1.270 respectively. CONCLUSIONS: AMH concentrations using the Gen II kit are slightly higher than those from the IOT and DSL kits. Standardization of assay results worldwide is urgently required but this analysis facilitates the interpretation of values obtained historically and in future studies using any of the 3 assays available. Meanwhile, adapting clinical cut-offs from previously published work by direct conversion is not recommended.