Analysis of Slow-Cycling Variants of the Light-Inducible Nuclear Protein Export System LEXY in Mammalian Cells.

The optogenetic tool LEXY consists of the second light oxygen voltage (LOV) domain of Avena sativa phototropin 1 mutated to contain a nuclear export signal. It allows exporting from the nucleus with blue light proteins of interest (POIs) genetically fused to it. Mutations slowing the dark recovery rate of the LOV domain within LEXY were recently shown to allow for better depletion of some POIs from the nucleus in Drosophila embryos and for the usage of low light illumination regimes. We investigated these variants in mammalian cells and found they increase the cytoplasmic localization of the proteins we tested after illumination, but also during the dark phases, which corresponds to higher leakiness of the system. These data suggest that, when aiming to sequester into the nucleus a protein with a cytoplasmic function, the original LEXY is preferable. The iLEXY variants are, instead, advantageous when wanting to deplete the nucleus of the POI as much as possible.

Genetic Engineering of Oligotropha carboxidovorans Strain OM5-A Promising Candidate for the Aerobic Utilization of Synthesis Gas.

Due to climate change and worldwide pollution, development of highly sustainable routes for industrial production of basic and specialty chemicals is critical nowadays. One possible approach is the use of CO2- and CO-utilizing microorganisms in biotechnological processes to produce value-added compounds from synthesis gas (mixtures of CO2, CO, and H2) or from C1-containing industrial waste gases. Such syngas fermentation processes have already been established, e.g., biofuel production using strictly anaerobic acetogenic bacteria. However, aerobic processes may be favorable for the formation of more costly (ATP-intensive) products. Oligotropha carboxidovorans strain OM5 is an aerobic carboxidotrophic bacterium and potentially a promising candidate for such processes. We here performed RNA-Seq analysis comparing cells of this organism grown heterotrophically with acetate or autotrophically with CO2, CO, and H2 as carbon and energy source and found a variety of chromosomally and of native plasmid-encoded genes to be highly differentially expressed. In particular, genes and gene clusters encoding proteins required for autotrophic growth (CO2 fixation via Calvin-Benson-Bassham cycle), for CO metabolism (CO dehydrogenase), and for H2 utilization (hydrogenase), all located on megaplasmid pHCG3, were much higher expressed during autotrophic growth with synthesis gas. Furthermore, we successfully established reproducible transformation of O. carboxidovoransvia electroporation and developed gene deletion and gene exchange protocols via two-step recombination, enabling inducible and stable expression of heterologous genes as well as construction of defined mutants of this organism. Thus, this study marks an important step toward metabolic engineering of O. carboxidovorans and effective utilization of C1-containing gases with this organism.

Alternating MOPP and ABVD chemotherapy plus mantle-field radiation therapy in patients with massive mediastinal Hodgkin's disease.

PURPOSE: To evaluate the efficacy and toxicity of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy plus mantle-field radiation therapy in the treatment of patients with massive mediastinal Hodgkin's disease of any stage. PATIENTS AND METHODS: Eighty patients presented with Hodgkin's disease and a mediastinal mass greater than one third the greatest chest diameter on chest radiograph. Patients were staged and treated with MOPP alternated with ABVD chemotherapy for a total of six cycles. Patients then received 10 Gy mantle-field radiation therapy delivered to the original extent of disease followed by 25 to 35 Gy to the residual abnormalities. RESULTS: The complete response (CR) rate was 89%. With a median follow-up duration of 10 years, disease-free survival of the complete responders is 78% at 15 years and overall survival is 75% at 15 years. For patients with stage I or II disease, disease-free survival was 76% at 15 years and overall survival was 79%; for those with stage III or IV disease, disease-free survival was 82% at 15 years and overall survival was 64%. Age, stage, sex, B symptoms, number of extranodal sites, lactate dehydrogenase (LDH) levels, erythrocyte sedimentation rate, and platelet count did not influence treatment outcome. Treatment-related pneumonitis was noted in 16% of patients (fatal in one), mainly in those older than age 35 years who received total doses of radiation therapy greater than 42 Gy. Fertility is more often preserved with MOPP/ABVD therapy than with MOPP chemotherapy and there appears to be less pulmonary and cardiac disease than with ABVD chemotherapy. Two patients have developed second solid tumors within radiation ports and one relapsed patient developed acute leukemia after MOPP salvage therapy. CONCLUSION: MOPP/ABVD followed by mantle-field radiation therapy is an effective treatment for all stages of Hodgkin's disease that present with a large mediastinal mass. Our data suggest that the large mediastinal mass is a more dominant determinant of prognosis than Ann Arbor stage or other clinical prognostic factors.

Treatment of advanced-stage Hodgkin's disease: alternating noncrossresistant MOPP/CABS is not superior to MOPP.

One hundred twenty-five assessable patients with advanced-stage Hodgkin's disease were randomized to receive mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) or MOPP alternating with lomustine (CCNU), doxorubicin, bleomycin, and streptozocin (CABS). The median follow-up is 7.7 years. The complete response rate was 60 of 66 MOPP-treated patients (91%) and 54 of 59 MOPP/CABS-treated patients (92%) (difference not significant). The level of the disease-free survival curve at longest follow-up is 65% for MOPP-treated patients and 72% for MOPP/CABS-treated patients (difference not significant). The overall survival at 12 years is projected at 68% for MOPP-treated patients and 54% for MOPP/CABS-treated patients (difference not significant). Thus, there were no significant differences in efficacy between MOPP and MOPP/CABS. However, MOPP/CABS was more emetogenic than MOPP, and four MOPP/CABS-treated patients went on to develop secondary acute leukemia. No MOPP-treated patients developed leukemia. High initial erythrocyte sedimentation rate (ESR) and high platelet counts adversely affected treatment outcome. MOPP-treated patients who received greater than 81% of the projected dose intensity of vincristine over the first three cycles had significantly improved disease-free survival rates over those receiving less than 81%. MOPP/CABS-treated patients who received greater than 82% of the projected dose intensity of vincristine had significantly better overall survival than those who received less than 82%. Disease-free survival on both arms was significantly better in patients who received greater than 84% of the projected dose intensity of all agents. The effect of dose intensity was particularly apparent in patients with poor prognostic factors where those who received greater than 84% of the projected dose intensity of all agents had significantly improved disease-free and overall survival.