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Aleksandrovic, E.

Publications and source records attributed to Aleksandrovic, E..

3 recordsLinked to original sources

A single chromosome 3p break initiates clear cell renal cell carcinoma evolution

Clear cell renal cell carcinoma (ccRCC) is initiated by chromosome 3p loss, yet chromosome losses impose a profound fitness burden on normal cells. How renal epithelial cells tolerate this deleterious aneuploidy during early tumorigenesis remains unclear. Analysis of 949 ccRCC genomes reveals two major classes of chromosome 3p alterations: simple deletions and complex rearrangements surrounding a terminal breakpoint - a pattern we term breakpoint-confined chromothripsis. We modeled both alterations in non-transformed human renal proximal tubule epithelial cells by introducing a single DNA double-strand break on chromosome 3p. Despite an initial fitness disadvantage, chromosome 3p loss drives adaptive genomic evolution that recapitulates recurrent ccRCC-associated aneuploidies, including 5q gain and 14q loss. These alterations alleviate the fitness constraints of 3p loss and promote metabolic reprogramming, clonal expansion, and malignant transformation, producing tumors with features of ccRCC. Thus, a single chromosome break initiates the evolutionary trajectory of ccRCC by creating a fitness bottleneck that selects for recurrent aneuploidies.

cancer biology↗

Hybrid In Vivo Breast Cancer Model Reveals Transcriptomic Insights into Cancer Progression with Age

Aging is a key risk factor for breast cancer, yet the independent role of the extracellular matrix (ECM) in tumor progression remains understudied. Recent studies have investigated healthy mammary tissue and aging to understand their relationship; however, the independent effects of the aged ECM remain understudied. Herein, we describe a hybrid in vivo model where MCF10A ductal carcinoma (DCIS.com) cells - with or without knockdown of select targets - were seeded onto decellularized ECM from aged murine mammary glands and implanted into the mammary fat pads of young Rag1-/- mice. Knockdown of selected targets, IL1B and LOX, reduced tumor growth on aged matrices in vivo and P4HA1 knockdown enhanced tumor growth. Additionally, analysis of LOX on aged ECM highlighted LOX as a driver of tumor progression where knockdown reduced transcriptomic programs related to invasion and cellular stress. To isolate the individual ECM influence on tumor growth, MCF10A cells were seeded atop young or aged matrices where it was found that tumors grown on the aged ECM after implantation exhibited significantly greater volume and a larger tumorigenic region when compared to those from the young ECM. Furthermore, single cell RNA-sequencing revealed transcriptional enrichment of inflammatory and invasive genes within the aged matrix. Together, these results identify LOX as a driver of tumor progression and potential therapeutic target, and demonstrate that the aged ECM alone can promote breast cancer progression

bioengineering↗

Temporal Clonal Tracing and Functional Perturbation Reveal Niche-Adaptive and Tumor-Intrinsic IFNγ Dependencies Driving Ovarian Cancer Metastasis

Metastasis is an emergent continuum driven by evolving reciprocal adaptations between disseminating tumor cells (DTCs) and specialized niches of different organs. The interplay between intrinsic and niche-driven mechanisms that enable DTCs to survive and home to distant organs in peritoneal ovarian cancer metastasis remains incompletely understood. Here, we present MetTag, a single-cell barcoding and transcriptome profiling approach with single cell clonality barcodes and time-stamped batch identifiers (BC.IDs) to resolve metastasis clonality and temporal dynamics of DTC colonization. Deep sequencing of MetTag barcodes revealed enrichment of early-disseminated clones across metastatic sites, and targeted depletion of pioneer DTCs diminished the outgrowth of subsequent arriving DTCs. Subsequent MetTag-coupled single cell RNA sequencing (scRNA-seq) on ascites and metastasis-bearing omenta revealed a distinct interferon-gamma (IFN{gamma})-centric transcriptional trajectory selectively enriched among pioneer clones. In vivo CRISPR/Cas9 screening of niche-specific signatures demonstrated that the tumor-intrinsic IFN{gamma} response is functionally required for peritoneal metastasis. Knockout of the IFN{gamma} receptor 1 (Ifngr1) in the initial pioneer DTCs significantly reduced total metastatic burden, revealing a critical window of time in which IFN{gamma} signaling shapes the post-seeding metastatic niche (PSMN) and subsequent metastatic evolution. Mechanistically, the tumor-intrinsic IFN{gamma} response induced Poly(ADP-Ribose) polymerase family member 14 (Parp14) and peritoneal macrophages cooperatively shield DTCs from anoikis by promoting pro-survival signaling. Our study defines the temporal clonal architecture of peritoneal niches and reveals a "first come, first served" adaptation principle, where pioneer colonizer fitness determines the success of subsequent colonizers.

cancer biology↗