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Biology subjects

Tagawa, S. T.

Publications and source records attributed to Tagawa, S. T..

3 recordsLinked to original sources

TMPO promotes cellular dissemination and metastasis in circulating tumor cells

Metastasis--the process by which cancer cells spread beyond the primary tumor to distant organs--accounts for the vast majority of cancer-related deaths. To elucidate mechanisms underlying dissemination and metastasis in prostate cancer, we have investigated circulating tumor cells (CTCs) obtained from genetically engineered mouse models (GEMMs). The phenotypic and molecular properties of the CTCs, and organoids derived from these CTCs, closely model the tumor and metastatic phenotypes of their parental GEMMs. Moreover, organoids derived from individual CTCs exhibit molecular and morphological heterogeneity that is associated with distinct metabolic states as well as differences in human prostate cancer outcome. Using computational systems analyses, we have identified TMPO, encoding the nuclear membrane protein lamina-associated polypeptide 2 (Lap2), as a key driver of this heterogeneity. TMPO activity is upregulated in advanced human prostate tumors, metastases, and CTCs, and is associated with adverse clinical outcome. Our findings indicate that TMPO promotes dissemination and metastasis in vivo by enhancing survival in conditions of metabolic stress, and reveal a novel mechanistic link between CTC heterogeneity, stress adaptation, and metastatic potential.

cell biology↗

The Interplay between Mutagenesis and Extrachromosomal DNA Shapes Urothelial Cancer Evolution

Advanced urothelial cancer is a frequently lethal disease characterized by marked genetic heterogeneity. In this study, we investigate the evolution of the genomic signatures caused by endogenous and external mutagenic stimuli and their interplay with complex structural variants. We superimposed mutational signatures and phylogenetic analyses of matched serial tumors from patients with urothelial cancer to define the evolutionary patterns of these processes. We show that APOBEC3-induced mutations are clonal and early, whereas mutational bursts comprising hundreds of late subclonal mutations are induced by chemotherapy. Using a novel genome graph computational paradigm, we observed frequent circular high copy-number amplicons characteristic of extrachromosomal DNA (ecDNA) involving double-minutes, breakage-fusion-bridge, and tyfonas events. We characterized the distinct temporal patterns of APOBEC3 mutations and chemotherapy-induced mutations within ecDNA, gaining new insights into the timing of these events relative to ecDNA biogenesis. Finally, we discovered that most CCND1 amplifications in urothelial cancer arise within circular ecDNA amplicons. These CCND1 ecDNA amplification events persisted and increased in complexity incorporating additional DNA segments potentially contributing selective fitness advantage to the evolution of treatment resistance. Our findings define fundamental mechanisms driving urothelial cancer evolution and have therapeutic implications for treating this disease.

genomics↗

A simple strategy to reduce the salivary gland and kidney uptake of PSMA targeting small molecule radiopharmaceuticals

The past five years have seen an increasing acceptance of peptide-based prostate-specific membrane antigen (PSMA)-targeted radionuclide therapy (TRT) agents for treatment of metastatic castration-resistant prostate cancer (mCRPC), with [177Lu]-DKFZ-PSMA-617 ([177Lu]-PSMA-617) emerging as the leading candidate. [177Lu]-PSMA-617 and other PSMA ligands have shown efficacy in reducing the tumor burden in mCRPC patients but irradiation to salivary gland and kidneys is a concern and dose limiting factor. Therefore, methods to reduce non-target organ toxicity are needed to safely treat patients and preserve their quality of life. Here, we report the effects of the addition of the cold PSMA ligand DKFZ-PSMA-11 (PSMA-11) on the uptake of [177Lu]-PSMA-617 in tumor, salivary glands and kidneys. Groups of athymic nude mice (n = 4) bearing PC3-PIP (PSMA+) tumor xenografts were administered with [177Lu]-PSMA-617 along with 0, 5, 100, 500, 1000 and 2000 pmoles of PSMA-11. Biodistribution studies 1 h post-administration revealed that [177Lu]-PSMA-617 uptake in PSMA-expressing PC3-PIP tumors was 21.71{+/-}6.13, 18.7{+/-}2.03, 26.44{+/-}2.94, 16.21{+/-}3.5, 13.52{+/-}3.68, and 12.03{+/-}1.96 %ID/g when 0, 5, 100, 500, 1000 and 2000 pmoles of PSMA-11 were added, respectively. Corresponding kidney uptake values were 123.14{+/-}52.52, 132.31{+/-}47.4, 84.29{+/-}78.25, 2.12{+/-}1.88, 1.16{+/-}0.36, 0.64{+/-}0.23 %ID/g, respectively. Corresponding salivary gland uptake values were 0.48{+/-}0.11, 0.45{+/-}0.15, 0.38{+/-}0.3, 0.08{+/-}0.03, 0.09{+/-}0.07, 0.05{+/-}0.02 % ID/g, respectively. Thus, uptake of PSMA TRT agents in salivary gland and kidney can be substantially reduced without impact on tumor uptake by adding cold PSMA-11. Our data provides proof-of-concept and we propose that similar strategy be pursued in future clinical trials to prevent xerostomia and renal toxicity arising from [177Lu]-PSMA-617.

pharmacology and toxicology↗