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Einstein, D. J.

Publications and source records attributed to Einstein, D. J..

4 recordsLinked to original sources

Fusion-driven oncogenic programs shape the immune landscape in translocation renal cell carcinoma

Renal cell carcinomas comprise multiple molecularly distinct cancers but most are treated empirically with therapies designed for clear cell RCC (ccRCC), the most common subtype, due to incomplete understanding of subtype-specific biology. We analyzed single-cell transcriptomes and chromatin accessibility profiles from translocation renal cell carcinoma (tRCC), an aggressive RCC defined by oncogenic TFE3 gene fusions. Unexpectedly, despite arising from a proximal tubule cell of origin similar to ccRCC, tRCCs display markedly distinct oncogenic programs and an immunosuppressive tumor microenvironment. tRCCs exhibit six conserved tumor meta-programs, including epithelial-mesenchymal transition and proximal tubule identity programs whose balance is regulated by TFE3 fusion activity. The fusion-driven EMT program drives a suppressive TME marked by progenitor-exhausted CD8+ T cells, anti-inflammatory SPP1+ macrophages, and matrix-associated fibroblasts (mCAFs). Our findings highlight unique TFE3 fusion-driven biology in tRCC, explaining its reduced immunotherapy responsiveness relative to ccRCC, and suggesting strategies for targeting fusion-driven oncogenic programs and TME reprogramming.

genomics↗

A genetic basis for cancer sex differences revealed in Xp11 translocation renal cell carcinoma

Xp11 translocation renal cell carcinoma (tRCC) is a female-predominant kidney cancer driven by translocations between the TFE3 gene on chromosome Xp11.2 and partner genes located on either chrX or on autosomes. The rearrangement processes that underlie TFE3 fusions, and whether they are linked to the female sex bias of this cancer, are largely unexplored. Moreover, whether oncogenic TFE3 fusions arise from both the active and inactive X chromosomes in females remains unknown. Here we address these questions by haplotype-specific analyses of whole-genome sequences of 29 tRCC samples from 15 patients and by re-analysis of 145 published tRCC whole-exome sequences. We show that TFE3 fusions universally arise as reciprocal translocations with minimal DNA loss or insertion at paired break ends. Strikingly, we observe a near exact 2:1 female:male ratio in TFE3 fusions arising via X:autosomal translocation (but not via X inversion), which accounts for the female predominance of tRCC. This 2:1 ratio is at least partially attributable to oncogenic fusions involving the inactive X chromosome and is accompanied by partial re-activation of silenced chrX genes on the rearranged chromosome. Our results highlight how somatic alterations involving the X chromosome place unique constraints on tumor initiation and exemplify how genetic rearrangements of the sex chromosomes can underlie cancer sex differences.

cancer biology↗

Polo-like kinase-1 Inhibitors and the Antiandrogen Abiraterone Synergistically Disrupt Mitosis and Kill Cancer Cells of Disparate Origin Independently of Androgen Receptor Signaling

Abiraterone, a standard treatment for metastatic castrate-resistant prostate cancer (mCRPC), slows disease progression by abrogating androgen synthesis and antagonizing the androgen receptor (AR). We report that inhibitors of the mitotic kinase Plk1, including the clinically active third-generation Plk1 inhibitor onvansertib, when co-administered with abiraterone, synergistically kill cancer cells from a wide variety of tumor types in an androgen-independent manner, both in vitro and in vivo. Abiraterone treatment alone results in defects in mitotic spindle orientation, failure of complete chromosome condensation, and upregulation of mitosis and mitotic-spindle related gene sets independently of its effects on AR signaling. These effects, while mild following abiraterone monotherapy, result in profound sensitization to the anti-mitotic effects of Plk1 inhibition, leading to spindle assembly checkpoint-dependent mitotic cell death and entosis. In a murine PDX model of mCRPC, combined onvansertib and abiraterone resulted in enhanced mitotic arrest and dramatic inhibition of tumor cell growth compared to either agent alone. STATEMENT OF SIGNIFICANCEA phase 2 clinical trial is underway (NCT03414034) testing combined Plk1 inhibitor onvansertib and abiraterone in mCRPC patients with nascent abiraterone resistance. Our work establishes a mechanistic basis for that trial and indicates that combined abiraterone and onvansertib co-treatment may have broad utility for cancer treatment beyond mCRPC.

cancer biology↗

Low abundance of circulating tumor DNA in localized prostate cancer

Despite decreased screening-based detection of clinically insignificant tumors, most diagnosed prostate cancers are still indolent, indicating a need for better strategies for detection of clinically significant disease prior to treatment. We hypothesized that patients with detectable circulating tumor DNA (ctDNA) were more likely to harbor aggressive disease. We applied ultra-low pass whole genome sequencing to profile cell-free DNA from 112 patients diagnosed with localized prostate cancer and performed targeted resequencing of plasma DNA for somatic mutations previously identified in matched solid tumor in nine cases. We also performed similar analyses on patients with metastatic prostate cancer. In all cases of localized disease, even in clinically high-risk patients who subsequently recurred, we did not detect ctDNA by either method in plasma acquired before surgery or before recurrence. In contrast, ctDNA was detected from patients with metastatic disease. Our findings demonstrate clear differences between localized and advanced prostate cancer with respect to the dissemination and detectability of ctDNA. Because allele-specific alterations in ctDNA are below the threshold for detection in localized prostate cancer, other approaches to identify cell-free nucleic acids of tumor origin may demonstrate better specificity for aggressive disease.

genomics↗