Publications by authors named "Sarah Amend"

Article Synopsis
  • The research investigates how prostate cancer adapts to changing environments and the role of the Polyaneuploid Cancer Cell (PACC) state in metastasis, suggesting that PACC can enhance metastatic potential.
  • Evidence from previous studies shows that the presence of PACC in patient tumors correlates with a higher risk of future metastasis, prompting the use of innovative methods to analyze circulating and disseminated tumor cells from animal models.
  • The findings reveal that a significant majority of these tumor cells were in the PACC state, and specific traits associated with PACC contribute to its ability to spread and colonize new sites, raising concerns about the effectiveness of certain cancer treatments that may inadvertently promote metastasis.
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  • Therapeutic resistance in cancer, especially in advanced prostate cancer, contributes to high mortality as patients often relapse after initial treatments.
  • Research on circulating tumor cells with increased genomic content (CTC-IGC) from 44 advanced prostate cancer patients reveals a link to poorer survival outcomes and clonal origins, indicating polyploidization.
  • Identification of new RNA and protein markers associated with chemotherapy resistance, such as HOMER1, TNFRSF9, and LRP1, suggests pathways for improving cancer treatment and understanding relapse mechanisms.
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Centrosomes serve as microtubule-organizing organelles that function in spindle pole organization, cell cycle progression, and cilia formation. A non-canonical role of centrosomes that has gained traction in recent years is the ability to act as signal transduction centers. Centrosome amplification, which includes numerical and structural aberrations of centrosomes, is a candidate hallmark of cancer.

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This study delves into the proteomic intricacies of drug-resistant cells (DRCs) within prostate cancer, which are known for their pivotal roles in therapeutic resistance, relapse, and metastasis. Utilizing single-cell proteomics (SCP) with an optimized high-throughput Data Independent Acquisition (DIA) approach with the throughput of 60 sample per day, we characterized the proteomic landscape of DRCs in comparison to parental PC3 cells. This optimized DIA method allowed for robust and reproducible protein quantification at the single-cell level, enabling the identification and quantification of over 1,300 proteins per cell on average.

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Therapeutic resistance in cancer significantly contributes to mortality, with many patients eventually experiencing recurrence after initial treatment responses. Recent studies have identified therapy-resistant large polyploid cancer cells in patient tissues, particularly in late-stage prostate cancer, linking them to advanced disease and relapse. Here, we analyzed bone marrow aspirates from 44 advanced prostate cancer patients and found the presence of CTC-IGC was significantly associated with poorer progression-free survival.

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Therapeutic resistance in cancer significantly contributes to mortality, with many patients eventually experiencing recurrence after initial treatment responses. Recent studies have identified therapy-resistant large polyploid cancer cells in patient tissues, particularly in late-stage prostate cancer, linking them to advanced disease and relapse. Here, we analyzed bone marrow aspirates from 44 advanced prostate cancer patients and found the presence of circulating tumor cells with increased genomic content (CTC-IGC) was significantly associated with poorer progression-free survival.

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Article Synopsis
  • There is a significant need to better understand how prostate cancer spreads, specifically the role of the Polyaneuploid Cancer Cell (PACC) state in this process.
  • Emerging research suggests that the PACC state enhances a cancer cell's ability to metastasize, with a retrospective study indicating that the presence of PACCs in prostate tissue can predict future metastasis.
  • Innovative flow-cytometric techniques reveal that a high percentage (74%) of circulating and disseminated tumor cells are in the PACC state, and further experiments demonstrate that these cells can regain the ability to proliferate at metastatic sites, linking PACCs to increased metastatic potential.
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models for tumorigenesis and metastasis have revealed conserved mechanisms of signaling that are also involved in mammalian cancer. Many of these models use the proliferating tissues of the larval stages of development, when tissues are highly mitotically active, or stem cells are abundant. Fewer tumorigenesis models use adult animals to initiate tumor formation when many tissues are largely terminally differentiated and postmitotic.

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To investigate extracellular vesicles (EVs), biomarkers for predicting lymph node invasion (LNI) in patients with high-risk prostate cancer (HRPCa), plasma, and/or urine samples were prospectively collected from 45 patients with prostate cancer (PCa) and five with benign prostatic hyperplasia (BPH). Small RNA sequencing was performed to identify miRNAs in the EVs. All patients with PCa underwent radical prostatectomy and extended pelvic lymph node dissection.

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  • Rapid detection of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) is vital for studying metastasis, as only a tiny fraction of cells successfully metastasize.
  • This study introduces a flow cytometry method for quickly comparing CTCs and DTCs from individual animals, facilitating the evaluation of different steps in cancer spread.
  • The method offers a reliable way to analyze rare cancer cells and has the flexibility to adapt for use in different tissues and research contexts, enhancing the understanding of metastatic processes.
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  • Cancer cell survival and growth are influenced by somatic evolution, which selects specific cell traits in response to changing environments.
  • Researchers analyzed lung adenocarcinomas with varied genetic mutations (n=313) and discovered a limited number (376) of mutations under positive selection linked to significant changes in gene expression.
  • Key pathways important for cancer cell fitness involve loss of normal tissue functions, with specific genes related to cell cycle, DNA repair, and metabolism showing significant conservation and increased expression in tumors.
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The evolution of metastasis represents a lethal stage of cancer progression. Yet, the evolutionary kinetics of metastatic disease remain unresolved. Here, using single cell CRISPR-Cas9 lineage tracing data, we show that in metastatic disease, gradual molecular evolution is punctuated by episodes of rapid evolutionary change associated with lineage divergence.

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To investigate extracellular vesicles (EVs) biomarkers for predicting lymph node invasion (LNI) in patients with high-risk prostate cancer (HRPCa), plasma and/or urine samples were prospectively collected from 45 patients with prostate cancer (PCa) and five with benign prostatic hyperplasia (BPH). Small RNA sequencing was performed to identify miRNAs in the EVs. All patients with PCa underwent radical prostatectomy and extended pelvic lymph node dissection.

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Chemoresistance is a major cause of treatment failure in many cancers. However, the life cycle of cancer cells as they respond to and survive environmental and therapeutic stress is understudied. In this study, we utilized a microfluidic device to induce the development of doxorubicin-resistant (DOXR) cells from triple negative breast cancer (TNBC) cells within 11 days by generating gradients of DOX and medium.

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Background: Lipid reprogramming is a known mechanism to increase the energetic demands of proliferating cancer cells to drive and support tumorigenesis and progression. Elevated lipid droplets (LDs) are a well-known alteration of lipid reprogramming in many cancers, including prostate cancer (PCa), and are associated with high tumor aggressiveness as well as therapy resistance. The mechanism of LD accumulation and specific LD functions are still not well understood; however, it has been shown that LDs can form as a protective mechanism against lipotoxicity and lipid peroxidation in the cell.

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Unlabelled: Therapeutic resistance and recurrence remain core challenges in cancer therapy. How therapy resistance arises is currently not fully understood with tumors surviving via multiple alternative routes. Here, we demonstrate that a subset of cancer cells survives therapeutic stress by entering a transient state characterized by whole-genome doubling.

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Article Synopsis
  • Researchers studied tiny particles called small extracellular vesicles (sEVs) to find out if they can show different types of bladder cancer.
  • They used special techniques to get and check these sEVs from bladder tissue, urine, and blood, finding that urine sEVs are mostly one type and blood sEVs another, even if the tissue says something different.
  • Four new important mRNA markers (FAM71E2, OR4K5, FAM138F, KRTAP26-1) were found that might help tell us more about bladder cancer, but more studies are needed to see if these markers work well in more patients.
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  • Evolvability refers to a population's ability to generate heritable variations that are relevant for natural selection, influencing individual adaptations and overall fitness.
  • The study models how different species with varying evolvability compete under different environmental conditions, revealing that faster-evolving species do better far from equilibrium, while slower-evolving species succeed when near equilibrium.
  • Environmental changes impact species survival, with frequent minor changes leading to the extinction of smaller populations, yet allowing for coexistence in diverse ecological niches, particularly favoring slower-evolving species.
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  • The polyaneuploid cancer cell (PACC) state helps cancer cells survive extreme conditions and spread more effectively, leading to increased lethality.
  • Recent findings indicate that cancer cells that recover from treatment show resistance to various therapies, which may result from a phenomenon called PACC memory, where cells quickly return to a resistant state.
  • This paper builds on mathematical models to explore the effects of innate resistance and PACC memory on cancer cell dynamics, suggesting that both factors play significant roles in resistance and survival in cancer populations.
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  • The prostate cancer tumor microenvironment (TME) contains various cell types, including macrophages that can be M1-like (anti-tumor) or M2-like (pro-tumor), with M2 macrophages playing a key role in efferocytosis, the process of engulfing dying cells.
  • Research suggests that targeting MerTK, a receptor involved in efferocytosis, may hinder tumor growth and enhance anti-tumor immune responses.
  • Initial findings from experiments show that M2 macrophages have a higher capacity for efferocytosis of prostate cancer cells and that inhibiting MerTK reduces this process, promoting a shift toward a more anti-tumor immune profile in a mouse model.
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The evolution of antibiotic resistance is a fundamental problem in disease management but is rarely quantified on a single-cell level owing to challenges associated with capturing the spatial and temporal variation across a population. To evaluate cell biological phenotypic responses, we tracked the single-cell dynamics of filamentous bacteria through time in response to ciprofloxacin antibiotic stress. We measured the degree of phenotypic variation in nucleoid length and the accumulation of protein damage under ciprofloxacin antibiotic and quantified the impact on bacterial survival.

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Most definitions of cancer broadly conform to the current NCI definition: "Cancer is a disease in which some of the body's cells grow uncontrollably and spread to other parts of the body." These definitions tend to describe what cancer "looks like" or "does" but do not describe what cancer "is" or "has become." While reflecting past insights, current definitions have not kept pace with the understanding that the cancer cell is itself transformed and evolving.

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Article Synopsis
  • Metastasis is rare at the cellular level, with only about 1 in 1.5 billion cancer cells capable of successfully completing the metastatic process.
  • Cells exhibiting a Polyaneuploid Cancer Cell (PACC) phenotype, characterized by enlargement and increased genomic content, have shown increased movement and adaptability in response to stress, which may enhance their metastasis competence.
  • Various techniques demonstrate that PACC cells possess hyper-elastic properties and express vimentin, suggesting they are better equipped for successful invasion and migration, warranting further investigation.
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The emergence of chemotherapy resistance drives cancer lethality in cancer patients, with treatment initially reducing overall tumor burden followed by resistant recurrent disease. While molecular mechanisms underlying resistance phenotypes have been explored, less is known about the cell biological characteristics of cancer cells that survive to eventually seed the recurrence. To identify the unique phenotypic characteristics associated with survival upon chemotherapy exposure, we characterized nuclear morphology and function as prostate cancer cells recovered following cisplatin treatment.

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Introduction: Congenital urinary obstruction is a common cause of end-stage renal disease in the pediatric population. However, non-invasive diagnostics to predict which patients will benefit from early intervention are lacking.

Methods: Using a rat model of upper and lower urinary tract partial obstruction and the Nanostring nCounter Fibrosis V2 Panel, we evaluated the mRNA cargo of urinary small extracellular vesicles (sEVs) and mRNA expression patterns of kidney and bladder tissues from rats with lower tract urinary obstruction and upper tract urinary obstruction.

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