ATR inhibition disrupts rewired homologous recombination and fork protection pathways in PARP inhibitor-resistant BRCA-deficient cancer cells

Poly-(ADP-ribose) polymerase (PARP) inhibitors (PARPis) selectively kill BRCA1/2-deficient cells, but their efficacy in BRCA-deficient patients is limited by drug resistance. Here, we used derived cell lines and cells from patients to investigate how to overcome PARPi resistance. We found that the functions of BRCA1 in homologous recombination (HR) and replication fork protection are sequentially bypassed during the acquisition of PARPi resistance. Despite the lack of BRCA1, PARPi-resistant cells regain RAD51 loading to DNA double-stranded breaks (DSBs) and stalled replication forks, enabling two distinct mechanisms of PARPi resistance. Compared with BRCA1-proficient cells, PARPi-resistant BRCA1-deficient cells are increasingly dependent on ATR for survival. ATR inhibitors (ATRis) disrupt BRCA1-independent RAD51 loading to DSBs and stalled forks in PARPi-resistant BRCA1-deficient cells, overcoming both resistance mechanisms. In tumor cells derived from patients, ATRis also overcome the bypass of BRCA1/2 in fork protection. Thus, ATR inhibition is a unique strategy to overcome the PARPi resistance of BRCA-deficient cancers

ATR inhibition disrupts rewired homologous recombination and fork protection pathways in PARP inhibitor-resistant BRCA-deficient cancer cells

Poly-(ADP-ribose) polymerase (PARP) inhibitors (PARPis) selectively kill BRCA1/2-deficient cells, but their efficacy in BRCA-deficient patients is limited by drug resistance. Here, we used derived cell lines and cells from patients to investigate how to overcome PARPi resistance. We found that the functions of BRCA1 in homologous recombination (HR) and replication fork protection are sequentially bypassed during the acquisition of PARPi resistance. Despite the lack of BRCA1, PARPi-resistant cells regain RAD51 loading to DNA double-stranded breaks (DSBs) and stalled replication forks, enabling two distinct mechanisms of PARPi resistance. Compared with BRCA1-proficient cells, PARPi-resistant BRCA1-deficient cells are increasingly dependent on ATR for survival. ATR inhibitors (ATRis) disrupt BRCA1-independent RAD51 loading to DSBs and stalled forks in PARPi-resistant BRCA1-deficient cells, overcoming both resistance mechanisms. In tumor cells derived from patients, ATRis also overcome the bypass of BRCA1/2 in fork protection. Thus, ATR inhibition is a unique strategy to overcome the PARPi resistance of BRCA-deficient cancers

Nanoparticle conjugates of a highly potent toxin enhance safety and circumvent platinum resistance in ovarian cancer

Advanced-stage epithelial ovarian cancers are amongst the most difficult to treat tumors and have proven to be refractory to most cytotoxic, molecularly targeted, or immunotherapeutic approaches. Here, we report that nanoparticle-drug conjugates (NDCs) of monomethyl auristatin E (MMAE) significantly increase loading on a per-vehicle basis as compared to antibody-drug conjugates (ADCs). Their intraperitoneal administration enabled triggered release of the active MMAE toxin to inhibit tumor growth and to extend animal survival to >90 days in a cell-line xenograft model of disseminated ovarian cancer. In a patient-derived xenograft model of advanced-stage and platinum-resistant ovarian cancer, an MMAE-based NDC doubled the duration of tumor growth inhibition as compared to cisplatin. NDCs of highly potent toxins thus introduce a translatable platform that may be exploited to maximize the safety and efficacy of cytotoxic chemotherapies, combining the best features of ADCs with those of nanoparticle-based therapeutics

Publisher Correction: Nanoparticle conjugates of a highly potent toxin enhance safety and circumvent platinum resistance in ovarian cancer

The original version of this Article contained an error in the spelling of the author Yingjie Yu, which was incorrectly given as Yu Yingjie. Furthermore, in Figure 3a, the labels ‘MD | p < 0.05’ incorrectly read ‘MD | p > 0.05’. These errors have now been corrected in both the PDF and HTML versions of the Article

Nanoparticle conjugates of a highly potent toxin enhance safety and circumvent platinum resistance in ovarian cancer

Advanced-stage epithelial ovarian cancers are amongst the most difficult to treat tumors and have proven to be refractory to most cytotoxic, molecularly targeted, or immunotherapeutic approaches. Here, we report that nanoparticle-drug conjugates (NDCs) of monomethyl auristatin E (MMAE) significantly increase loading on a per-vehicle basis as compared to antibody-drug conjugates (ADCs). Their intraperitoneal administration enabled triggered release of the active MMAE toxin to inhibit tumor growth and to extend animal survival to > 90 days in a cell-line xenograft model of disseminated ovarian cancer. In a patient-derived xenograft model of advanced-stage and platinum-resistant ovarian cancer, an MMAE-based NDC doubled the duration of tumor growth inhibition as compared to cisplatin. NDCs of highly potent toxins thus introduce a translatable platform that may be exploited to maximize the safety and efficacy of cytotoxic chemotherapies, combining the best features of ADCs with those of nanoparticle-based therapeutics

Publisher Correction: Nanoparticle conjugates of a highly potent toxin enhance safety and circumvent platinum resistance in ovarian cancer

The original version of this Article contained an error in the spelling of the author Yingjie Yu, which was incorrectly given as Yu Yingjie. Furthermore, in Figure 3a, the labels 'MD | p  0.05'. These errors have now been corrected in both the PDF and HTML versions of the Article

Sähkönlaadun ja energiankulutuksen tutkimus

Opinnäytetyössä tutkitaan sähkönlaadun ja energiankulutusta Raute Oyj:n rakentamissa vaneri- ja LVL-viilupalkkikoneissa. Opinnäytetyön tarkoituksena on selvittää esiintyykö Raute Oyj:n valmistamissa koneissa sähkönlaatua heikentäviä tekijöitä, kuten harmonisia yliaaltoja. Sähkönlaatua heikentävien tekijöiden lisäksi opinnäytetyössä selvitetään mahdollisuutta moottorikeskusten mitoituksessa käytettävän korjauskertoimen tarkentamiselle. Opinnäytetyön teoriaosassa esitellään sähkönlaatuun vaikuttavia tekijöitä, sekä niiden vaikutuksia sähköverkkoon ja verkonkäyttäjälle. Lisäksi teoriaosassa käydään läpi ratkaisuja, joilla esimerkiksi sähköverkossa esiintyvien yliaaltojen pitoisuutta voidaan vähentää tai poistaa kokonaan. Verkossa esiintyville häiriöille kuten harmonisille yliaalloille, taajuuden ja jännitteen vaihteluille on määritelty rajoituksia standardilla SFS-EN 50160, myös näitä rajoituksia ja niiden vaikutuksia sähkönlaatuun käydään läpi opinnäytetyön teoriaosassa. Sähkönlaatua ja energiankulutusta mitattiin kahdessa Raute Oyj:n koneessa, ja näiden mittaukseen käytettiin Fluken power quality analyzer mallia olevaa mittalaitetta. Mittaustuloksissa huomattiin sähkönlaadun olevan yleisesti hyvällä tasolla ja täyttävän standardissa SFS-EN 50160 sähkönlaadulle määritellyt raja-arvot. Tulosten perusteella huomattiin myös, että joissakin tapauksissa keskusten mitoituksessa käytettäviä korjauskertoimia pystyy tarkentamaan.The study researches the quality of electricity and the energy consumption on plywood and laminated veneer lumber (LVL) machines manufactured by Raute Plc. The Thesis aims to examine the potential existence of factors reducing the quality of electric, such as harmonic waves, on machines manufactured by Raute Plc. In addition to examine the electricity quality and consumption of energy, the thesis looks into the possibility of elaboration of motorcabin’s equalisation. The theory part of the Thesis presents factors that influence electric quality, as well as their influences on the electricity network and network’s users. Additionally, the theory part discusses solutions, which for instance reduce or eliminate harmonic waves in electric network. SFS-EN 50160 standard defines restrictions for disturbance in electric network such as harmonic waves, frequency and voltage variation, these restrictions are also presented in the theory part of the Thesis. In this study, electric quality and energy consumption were measured in two different machines manufactured by Raute Plc, and the measurements were conducted by Fluke power quality analyser measuring device. Electric quality was generally high according to the measurements, and it meets the electric quality standards defined in SFS-EN 50160. The measurements also indicated that in some cases the equalisation is possible to elaborate