Biology subjects

Gianfrancesco, F.

Publications and source records attributed to Gianfrancesco, F..

5 recordsLinked to original sources

bioRxiv2026

ZNF687 couples bone marrow myeloid progenitor dynamics toosteoclastogenesis in severe Paget's disease of bone

Pagets disease of bone (PDB) is a late-onset skeletal disorder characterized by excessive osteoclast-mediated bone remodelling and disorganized bone deposition. The P937R mutation in the ZNF687 gene causes a severe form of PDB complicated by giant cell tumour transformation. Although ZNF687 has been implicated in osteoclastogenesis, whether it regulates upstream haematopoietic progenitor dynamics and bone marrow myeloid output remains unclear. Using a constitutive Zfp687 knock-out mouse model, we showed that Zfp687 loss causes postnatal growth restriction, reduced bone marrow cellularity, impaired osteoclast differentiation in vitro and in vivo, and increased trabecular bone mass during adulthood. Flow cytometry revealed a marked reduction in osteoclast progenitors and macrophages in Zfp687-deficient bone marrow, whereas the pagetic P937R mutation promoted the expansion of the same myeloid populations in the Zfp687P937R knock-in mouse model. Single-cell RNA sequencing of bone marrow-derived c-Kit+ haematopoietic progenitors further demonstrated that Zfp687 loss selectively disrupted the myeloid progenitor compartment. This analysis identified 22 transcriptionally distinct populations and revealed a significant depletion of the early cycling granulocyte-monocyte progenitor cluster, without evidence of a global block in myeloid differentiation. Mechanistically, Zfp687 deficiency impaired the Brd4-c-Myc-NFATc1 axis in osteoclastogenic precursors and reduced Csf1 expression in bone marrow stromal and osteoblastic cells, linking intrinsic transcriptional competence to niche-derived M-CSF support. In pagetic patient iPSCs-derived haematopoietic progenitors, the P937R mutation enhanced clonogenic haematopoietic output, accelerated colony formation, and promoted the expansion of primitive/multipotent colony-forming progenitors, leading to hypercellular myeloid colonies. Together, our findings establish ZNF687 as a regulator of haematopoietic progenitor dynamics that couples bone marrow myeloid output to osteoclastogenesis, providing a progenitor-level mechanism for severe ZNF687-related PDB.

cancer biology↗

bioRxiv2026

Profilin 1 maintains cell cycle fidelity to prevent unscheduled genome doubling and polyploidy in cancer

Whole-genome doubling (WGD) represents a major route to genome instability and therapeutic resistance in cancer; yet, the mechanisms enabling genome duplication in p53-proficient cells remain poorly understood. Here, we identify Profilin 1 (PFN1) loss as a driver of WGD through impaired mitotic entry. Using FUCCI live-cell imaging and single-cell genomic profiling, we show that PFN1-deficient cells bypass mitosis and undergo endoreplication, generating tetraploid cells. Rather than undergoing stable arrest after mitotic bypass, these genome-doubled cells retain proliferative capacity and proceed through aberrant mitotic divisions, thereby amplifying genomic instability. Proteomic analyses reveal coordinated attenuation of late cell-cycle programs, including downregulation of key mitotic regulators such as CDK1, PLK1 and CKS2, consistent with impaired G2/M transition. Despite accumulating polyploidy, PFN1-knockout cells fail to activate an effective p53 tetraploidy checkpoint and display increased nuclear MDM2, promoting cell-cycle arrest evasion and chemotherapeutic resistance. We supported clinical relevance by an orthotopic osteosarcoma xenograft model, in which PFN1-deficient SaOS2 cells showed enhanced metastatic dissemination, and by pan-cancer TCGA analyses confirming a recurrent association between PFN1 loss and WGD. Together, these findings identify Profilin 1 as a safeguard of cell-cycle fidelity whose loss enables genome doubling, cellular plasticity and therapy tolerance.

cancer biology↗

bioRxiv2022

The ZNF687 mutation of Paget's disease associated with giant cell tumour causes severe bone remodelling alteration as a result of a deregulated osteoclast transcriptional program

Pagets disease (PDB) is a late-onset bone remodelling disorder with a broad spectrum of symptoms and complications. One of the most aggressive forms is caused by the P937R mutation in the ZNF687 gene. Although the genetic involvement of ZNF687 in PDB has been extensively studied, the molecular mechanisms underlying this association remains unclear. Here, we describe the first Zfp687 knock-in mouse model and demonstrate that the mutation recapitulates the PDB phenotype, showing a severe bone remodelling alteration. Through micro-computed tomography analysis, we observed that 8-month-old mice showed a mainly osteolytic phase, with a significant decrease in the trabecular bone volume affecting the femurs and the vertebrae of both heterozygous and homozygous mutant mice. In contrast, osteoblast activity was deregulated, beginning to produce disorganised bone. Noteworthy, this phenotype became pervasive in 16-month-old mice, where osteoblast function overtook bone resorption as the predominant event, as highlighted by the presence of woven bone in histological analyses, consistent with the PDB phenotype. Furthermore, we detected osteophytes and intervertebral disc degeneration, outlining for the first time the link between osteoarthritis and PDB in a PDB mouse model. Finally, we generated CRISPR-Cas9-based Zfp687 knock-out RAW 264.7 cells, and noted a remarkable impairment of osteoclast differentiation capacity, reinforcing the relevance of Zfp687 during this process. RNA-sequencing on wild type and KO clones identified a set of genes involved in osteoclastogenesis under the control of Zfp687, i.e., Tspan7, Cpe, Vegfc, and Ggt1. Thus, this study established an essential role of Zfp687 in the regulation of bone remodelling, and may offer the potential to therapeutically treat PDB.

cell biology↗

bioRxiv2022

Profilin 1 deficiency drives mitotic defects and impairs genome stability

Profilin 1 -encoded by PFN1- is a small actin-binding protein with a tumour suppressive role in various adenocarcinomas and pagetic osteosarcomas. However, its contribution to tumour development is not fully understood. Using fix and live cell imaging, we report that Profilin 1 inactivation results in multiple mitotic defects, manifested prominently by anaphase bridges, multipolar spindles, misaligned and lagging chromosomes, and cytokinesis failures. Accordingly, next-generation sequencing technologies highlighted that Profilin 1 knock-out cells display extensive copy-number alterations, which are associated with complex genome rearrangements and chromothripsis events in primary pagetic osteosarcomas with Profilin 1 inactivation. Mechanistically, we show that Profilin 1 is recruited to the spindle midzone at anaphase, and its deficiency reduces the supply of actin filaments to the cleavage furrow during cytokinesis. The mitotic defects are also observed in mouse embryonic fibroblasts and mesenchymal cells deriving from a newly generated knock-in mouse model harbouring a Pfn1 loss-of-function mutation. Furthermore, nuclear atypia is also detected in histological sections of mutant femurs. Thus, our results indicate that Profilin 1 has a role in regulating cell division, and its inactivation triggers mitotic defects, one of the major mechanisms through which tumour cells acquire chromosomal instability.

cell biology↗

bioRxiv2020

Early Alpine human occupation backdates westward human migration in Late Glacial Europe

The end of the Last Glacial Maximum (LGM) in Europe (~16.5 ka ago) set in motion major changes in human culture and population structure1. In Southern Europe, Early Epigravettian material culture was replaced by Late Epigravettian art and technology about 18-17 ka ago at the beginning of southern Alpine deglaciation, although available genetic evidence from individuals who lived ~14 ka ago2-5 opened up questions on the impact of migrations on this cultural transition only after that date. Here we generate new genomic data from a human mandible uncovered at the Late Epigravettian site of Riparo Tagliente (Veneto, Italy), that we directly dated to 16,980-16,510 cal BP (2{sigma}). This individual, affected by a low-prevalence dental pathology named focal osseous dysplasia, attests that the very emergence of Late Epigravettian material culture in Italy was already associated with migration and genetic replacement of the Gravettian-related ancestry. In doing so, we push back by at least 3,000 years the date of the diffusion in Southern Europe of a genetic component linked to Balkan/Anatolian refugia, previously believed to have spread during the later Bolling/Allerod warming event (~14 ka ago4,6). Our results suggest that demic diffusion from a genetically diverse population may have substantially contributed to cultural changes in LGM and post-LGM Southern Europe, independently from abrupt shifts to warmer and more favourable conditions.

genomics↗