Róża Przanowska
@rprzanowska.bsky.social
NCI K00 Fellow in Janes Lab at U of Virginia BME (USA) working on ncRNAs in breast cancer. PhD on ncRNAs in myogenesis in Dutta lab at UVA BMG. MSc from U of Warsaw (Poland). Mom of three and wife of Dr. Piotr Przanowski, scientist and HEMA fighter.
Grateful to all co-authors! Special thanks to Drs. Dutta and Leone for initiating this #collaboration. This project has been an incredible journey of discovery, allowing me to learn and grow. Big thanks to the NCI K00 for their support!
Taken together, these results demonstrate that hepatocytes can synthesize DNA via endoreduplication, enabling liver regeneration even without two ORC subunits. #ORC #Endoreduplication #LiverRegeneration
Partial #hepatectomy performed on dKO male mouse livers yielded similar liver sizes compared to WT counterparts, yet hepatocyte nuclei were larger in dKO males. Moreover, the percentage of nuclei stained with EdU was higher in the #regenerating livers of dKO mice.
dKO female mice showed a significant decrease in size. We have also observed ~50% lethality of dKO female mice within the first month of life, but the remaining 50% survive beyond 4 months of age. #Female dKO mice suffer more #morbidity and #mortality than male mice.
The double knockout (dKO) of Orc1 and Orc2 led to another round of intriguing findings. H&E staining showed that dKO female livers exhibited significantly fewer but larger cells with notably larger nuclei compared to male livers. #SexSpecificDifferences
Histological examination of the livers unveiled that Orc2 deletion correlated with the presence of fewer, yet larger nuclei and cells. Our flow cytometry analysis further substantiated that Orc2 deletion promotes endo-reduplication in #hepatocytes.
By employing #liver specific Alb-Cre, we found that body weights of the Alb-Orc2f/f mice were smaller than in the Orc2f/f animals of both sexes, though the liver size and liver size normalized to body weight was significantly smaller only in the females.
Through the breeding of Orc2f/f mice with Sox2-Cre mice, our study demonstrated the essential role of ORC2 in #embryonic #development. Notably, the proliferation rate of Orc2f/f mouse embryonic fibroblasts (MEF) infected with adeno-Cre was significantly impaired.
In the case of #endoreduplication in mouse liver in Orc1 conditional KO, one could argue that CDC6 was substituting for ORC1 based on its homology, thereby restoring functional ORC. Hence, we opted for a conditional mutation in Orc2, lacking this homology, to explore its effects.
Despite the critical role of the Origin Recognition Complex (ORC) in loading MCM2-7 at DNA #replication origins, instances of DNA replication have been observed even with individual ORC subunits virtually absent.
Excited to share our latest preprint on endo-reduplication in mouse liver after conditional ORC2 KO and ORC1&ORC2 double KO. Dive into the fascinating world of #DNA #replication with #DuttaLab at UVA and UAB!
Endo-reduplication in mouse liver after conditional mutation of ORC2 and combined mutation of ORC1 and ORC2
bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
www.biorxiv.org
Big shoutout to all co-authors! Special thanks to Najwa, Piotr,
Rusty, Dr. Atkins, Dr. Showalter, and Dr. Janes. This project has been incredibly rewarding, and I'm grateful for the opportunity to collaborate with such a talented team. #Teamwork
Zero-passage organoids redefine personalized medicine! Each set of molecular and genetic perturbations represents an n-of-1 study. Unlike traditional clinical trials, organoids allow for paired designs with control, alternative, and interactive arms, empowering interpretations.
Zero-passage organoids are a rapid and scalable way to interrogate properties of luminal breast cancer cells from patient-derived material. Our adaptation of this innovative system allows for parallel testing of both genetic and pharmacologic perturbations.
Our research showcases how the zero-passage organoids enable the testing of mechanisms of action, integrating genetic and small molecule perturbations. Combinatorial phenotyping of NQO1 depletion and sulforaphane treatment revealed three distinct classes of responses.
Seeking a vector to minimize Cas9 expression risk and enhance knockout efficiency with dual-sgRNAs? Look no further! Our team has developed a full series of plasmids featuring Venus, BFP, PuroR, and BlastR markers. Elevate your research with precision and reliability.
Although luminal breast epithelial cells are difficult to transfect or transduce, we achieved 89% of transduction efficiency without affecting organoids growth. To perform loss-of-function studies we pursued a regulatable approach using new pDual_dsCas9_Venus (@addgene.bsky.social #214678).
Using progressive concentrations of 4-hydroxytamoxifen we demonstrated that zero-passage luminal breast cancer organoids exhibit patient-specific sensitivity to hormone interventions. Our timeline is sufficient to distinguish those differences in luminal cancer cell growth.
Maximizing the utility of patient samples is crucial in research. We further miniaturized the culture volumes, demonstrating that 5 µl drops sustain healthy organoid growth. Successful isolations yield approximately 12 separate 5 µl drops, enabling parallel testing.
Using #RNAseq in combination with #CIBERSORTx on paired tumor scrapes, 3D organoids and 2D cultured cells, we discovered that zero-passage organoids generally retain the proportion of luminal cells, whereas 2D cultures did not, illustrating the importance of #matrigel cues.
We found that prolonged culture of #organoids causes death and loss of hormone receptors. Setting a 14-day experimental endpoint ensures that zero-passage organoids retain luminal characteristics of primary tumors, making them the optimal model for studying luminal breast cancer.
Grateful for the incredible teamwork of surgeons, pathology staff, and students! Together, we've redesigned the standard pipeline for processing breast tumor resections. Our method ensures efficient collection of tumor scrapes without diverting bulk material from pathology.
My first postdoctoral preprint from Janes lab at UVA BME is now live! We introduce patient-derived zero-passage organoids of luminal breast cancer.
Ever yearned for a more accurate model to study your disease of interest? Dive into our findings:
www.biorxiv.org/content/10.1...
Patient-derived response estimates from zero-passage organoids of luminal breast cancer
bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
www.biorxiv.org
It was a pleasure to be a panelist at today's Women's Mental Health Panel discussion organized by UVA GBMES DEI Co-chairs. Thank you for the invitation! I really enjoyed sharing my own perspective and learning more from other panellists.
Happy International Women's Day!
To all parents and amphibians enthusiasts: this book is a must read! We just finished it with our 4 and 6 yo, had so much fun and all of us learned something new. The suggested age group is 9-13, but I think everyone can find this book interesting. It is beautifully illustrated and well-written.
Happy #InternationalDayofWomenAndGirlsinScience to all fellow scientists and future ones! Special thanks to all women in the past who pioneered the road for me and others!
Graphic from fabulous project Nauka To Lubie (Tomasz Rozek)
That was a good meeting! Commonwealth of Virginia Cancer Research Conference 2023 just finished. It was a pleasure to co-organize this meeting, present my research, and listen to all the talks! Thank you #CVCRC2023 and looking forward to #CVCRC2025
How to convince my husband to buy more swords?
#HEMA #SwordFighting
Not a Night Rider, but a Night Writer.
The night fuels my creativity, and I'm on a Word document adventure. No leather jackets, just a blanket, cup of tea, and a laptop. Cheers to the night writers!
#DoubleManuscriptWriting #NightWriters