Showing papers by "Kenneth J. Pienta published in 2023"

WNT pathway mutations in metachronous oligometastatic castration-sensitive prostate cancer.

Abstract: WNT signaling is a cellular pathway that has been implicated in the development and progression of prostate cancer. Oligometastatic castration-sensitive prostate cancer (omCSPC) represents a unique state of disease in which metastasis-directed therapy (MDT) has demonstrated improvement in progression-free survival. Herein, we investigate the clinical implications of genomic alterations in the WNT signaling cascade in men with omCSPC.We performed an international multi-institutional retrospective study of 277 men with metachronous omCSPC who underwent targeted DNA sequencing of their primary/metastatic tumor. Patients were classified by presence or absence of pathogenic WNT pathway mutations (in the genes APC, RNF43, and CTNNB1). Pearson χ2 and Mann-Whitney U tests were used to determine differences in clinical factors between genomic strata. Kaplan-Meier survival curves were generated for radiographic progression-free survival and overall survival, stratified according to WNT pathway mutation status.A pathogenic WNT pathway mutation was detected in 11.2% of patients. Patients with WNT pathway mutations were more likely to have visceral metastases (22.6% vs 2.8%; P < .01) and less likely to have regional lymph node metastases (29.0% vs 50.4%; P = .02). At time of oligometastasis, these patients were treated with MDT alone (33.9%), MDT + limited course of systemic therapy (20.6%), systemic therapy alone (22.4%), or observation (defined as no treatment for ≥6 months after metastatic diagnosis). Multivariable cox regression demonstrated WNT pathway mutations associated with significantly worse overall survival (hazard ratio, 3.87; 95% confidence interval, 1.25-12.00).Somatic WNT pathway alterations are present in approximately 11% of patients with omCSPC and are associated with an increased likelihood of visceral metastases. Although these patients have a worse natural history, they may benefit from MDT.

Dormant cancer cells: programmed quiescence, senescence, or both?

Abstract: Abstract Metastasis is the overwhelming driver of cancer mortality, accounting for the majority of cancer deaths. Many patients present with metastatic relapse years after eradication of the primary lesion. Disseminated cancer cells can undergo a durable proliferative arrest and lie dormant in secondary tissues before reentering the cell cycle to seed these lethal relapses. This process of cancer cell dormancy remains poorly understood, largely due to difficulties in studying these dormant cells. In the face of these challenges, the application of knowledge from the cellular senescence and quiescence fields may help to guide future thinking on the study of dormant cancer cells. Both senescence and quiescence are common programs of proliferative arrest that are integral to tissue development and homeostasis. Despite phenotypic differences, these two states also share common characteristics, and both likely play a role in cancer dormancy and delayed metastatic relapse. Understanding the cell biology behind these states, their overlaps and unique characteristics is critical to our future understanding of dormant cancer cells, as these cells likely employ some of the same molecular programs to promote survival and dissemination. In this review, we highlight the biology underlying these non-proliferative states, relate this knowledge to what we currently know about dormant cancer cells, and discuss implications for future work toward targeting these elusive metastatic seeds.

Lack of repeatability of radiomic features derived from PET scans: Results from a 18F‐DCFPyL test–retest cohort

Abstract: PET‐based radiomic metrics are increasingly utilized as predictive image biomarkers. However, the repeatability of radiomic features on PET has not been assessed in a test–retest setting. The prostate‐specific membrane antigen‐targeted compound 18F‐DCFPyL is a high‐affinity, high‐contrast PET agent that we utilized in a test‐retest cohort of men with metastatic prostate cancer (PC).

Abstract 5988: A non-canonical CDK9 complex mediates endocycling in polyaneuploid cancer cell (PACC) state

Abstract: Once prostate cancer has spread from its primary site, treatment is limited to systemically administered therapy. While tumors initially respond to these therapies, eventually, all therapies fail, and the tumor recurs. Ours and others' recent studies have shown the presence of a universal mechanism of resistance: accession of the polyaneuploid cancer cell (PACC) state. The PolyAneuploid Transition (PAT) is initiated when a cancer cell is subjected to external stress, including therapy (we have tested three classes of chemotherapy and radiation), and accesses an alternative non-mitotic cell cycle known as endocycling, resulting in a greater-than-G2 polyploidization of the aneuploid genome (polyaneuploidy). While in this pro-survival PACC state, we have shown that cells are resistant to all forms of cytotoxic therapy. Initial RNA sequencing of cells that have accessed the PACC state in response to multiple classes of chemotherapy, including docetaxel and cisplatin, demonstrate a remodeled transcriptional profile that is distinct from control cultures. We hypothesize that accession of the resistance-mediating PACC state requires transcriptional remodeling. Our data show that cells in the PACC state had increased overall transcriptional activity. The multi protein complex pTEFB (positive transcription elongation factor) is a critical driver of RNA Polymerase II function and is composed of multiple subunits, including CDK9, a cyclin regulatory subunit, and a transcription factor. CDK9 phosphorylation was significantly elevated during accession and persistence in the PACC state. Genetic inhibitionof CDK9 by siRNA led to decreased expression of cyclin A which plays a role in S phase, both in the mitoticcycle and in the PACC endocycle. Interestingly, despite increased CDK9 levels, known CDK9 pTEFb complex members cyclin T1 and BRD4 were both decreased in cells in the PACC state. We treated cancer cells induced to enter the PACC state upon exposure to cisplatin with pharmaceutical inhibitors of CDK9, Flavopiridol and Fadraciclib. Combination of CDK9 inhibition with chemotherapy showed a suppressive effect on the PACC population. Our findings therefore suggest that a non-canonical CDK9 complex could be critical role for the endocycling to access and maintain the PACC state and represents a therapeutic candidate to eliminate the resistance-mediating PACC state. Citation Format: Cheng-fan Lee, Michael Loycano, Luke LOFTUS, Laurie Kostecka, Melvin Li, Sarah Amend, Kenneth Pienta. A non-canonical CDK9 complex mediates endocycling in polyaneuploid cancer cell (PACC) state. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5988.

Genomic determinants of patterns of failure in metachronous oligometastatic castration-sensitive prostate cancer.

Abstract: 238 Background: Oligometastatic castration-sensitive prostate cancer (omCSPC) represents an early state along the progression of metastatic disease in which patients experience improved outcomes compared to those with higher disease burden. Despite the generally more indolent nature, much heterogeneity still exists with some patients experiencing a more aggressive clinical course unexplained by clinical features alone. Here we correlate tumor genomics with modes of progression (MOP) and patterns of failure (POF) following treatment for omCSPC. Methods: We performed an international multi-institutional retrospective study of men treated for metachronous omCSPC, who underwent tumor next generation sequencing (NGS) with at least 1 year of follow-up. Descriptive POF and MOP were reported with respect to presence of genomic alterations in pathways of interest. Genomic pathways of interest included TP53, SPOP, WNT ( APC, CTNNB1, RNF43), DNA double strand break repair, cell cycle genes ( Rb1, CCND1–3, CDKN1B, and CDKN2A), and PI3K/AKT/mTOR. MOP were defined as oligoprogression (1-3 lesions), polyprogression (≥4 lesions), or long-term control (LTC, no radiographic progression at last follow-up). POF included location of lesions at first failure. Overall survival (OS) was calculated by the Kaplan-Meier method. Genomic associations with patterns/modes of failure were compared with chi-square test. Results: 221 patients were included for analysis with the majority having either 1 (47.5%) or 2 (27.3%) metastatic lesions at oligometastasis. 5-yr OS was associated with MOP 92% vs 89% vs 69% (p<0.01) for LTC, oligo- and polyprogression respectively. TP53 mutations were associated with significantly lower rates of LTC (24.4% vs 46%, p<0.01) and cell cycle mutations associated with high rates of polyprogression (36.7% vs 15.7%, p<0.01). With respect to POF, bone failure was significantly more common within tumors harboring mutations in TP53 (41.2% vs 23.1%, p=0.01) and less common with SPOP mutations (4.2% vs 27.8%, p=0.02). Finally, visceral failures were more common in tumors harboring either WNT pathway (20% vs 5.1%, p<0.01) or SPOP (17.4% vs 5.2%, p=0.04) mutations. Notably, SPOP and WNT pathway mutations cluster together (p<0.01). Conclusions: Tumor genomics provides novel insight into patterns of failure and modes of progression following treatment for metachronous omCSPC. Patients with TP53 and cell cycle mutations have a higher likelihood of progression and TP53, SPOP, and WNT pathway mutations may have a role in metastatic organotropism.

Test–retest repeatability of organ uptake on PSMA‐targeted 18F‐DCFPyL PET/CT in patients with prostate cancer

Abstract: We evaluated 18F‐DCFPyL test–retest repeatability of uptake in normal organs.

Exploration of Mechanisms of Drug Resistance in a Microfluidic Device and Patient Tissues

Abstract: 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. In vivo chemoresistant xenograft models, an unbiased genome-wide transcriptome analysis, and a patient data/tissue analysis all showed that chemoresistance arose from failed epigenetic control of the nuclear protein-1 (NUPR1)/histone deacetylase 11 (HDAC11) axis, and high Nupr1 expression correlated with poor clinical outcomes. These results suggest that the chip can rapidly induce resistant cells that increase tumor heterogeneity and chemoresistance, highlighting the need for further studies on the epigenetic control of the NUPR1/HDAC11 axis in TNBC.

Updating the definition of cancer.

Abstract: Most definitions of cancer broadly conform to the current National Cancer Institute 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. We propose a revised definition of cancer: Cancer is a disease of uncontrolled proliferation by transformed cells subject to evolution by natural selection. We believe this definition captures the essence of the majority of previous and current definitions. To the simplest definition of cancer as a disease of uncontrolled proliferation of cells, our definition adds in the adjective "transformed" to capture the many tumorigenic processes that cancer cells adopt to metastasize. To the concept of uncontrolled proliferation of transformed cells, our proposed definition then adds "subject to evolution by natural selection." The subject to evolution by natural selection modernizes the definition to include the genetic and epigenetic changes that accumulate within a population of cancer cells that lead to the lethal phenotype.

Abstract 4842: Stress-induced mitochondrial adaptations in the polyaneuploid cancer cell state

Abstract: Metastatic cancer is responsible for 90% of cancer deaths and is incurable due to resistance to all systemic anticancer therapies. While the classic model of therapy resistance is described by the presence of pre-existing resistant clones from tumor cell heterogeneity, our lab proposes the polyaneuploid cancer cell (PACC) state as a survival mechanism that cancer cells access when exposed to environmental stress such as hypoxia and chemotherapy. Our preliminary data has shown that cells that enter the PACC state exhibit repeated whole genome doubling, an increase in cell size, and proliferative arrest. In addition, we observed that a subpopulation of PACCs can give rise to non-polyploid, proliferative progeny after release from chemotherapy, modeling cancer recurrence. We hypothesize that the PACC state drives therapeutic resistance and elimination of this adaptive state is key in tackling the incurability of cancer. Mitochondria are essential organelles that have multifaceted roles in the cellular stress response and drug resistance. They integrate metabolic pathways for ATP generation and macromolecule biosynthesis, regulate apoptotic cell death, and activate stress response mechanisms in presence of drug treatment. We found that cells in the PACC state increase mitochondrial biogenesis and live cell imaging with MitoTraker dyes indicate that they also have higher activity per mitochondria when compared to parental cells. Cells that accessed the PACC state also had higher levels of TCA cycle metabolites including citrate, isocitrate, alpha-ketoglutarate, succinate, fumarate, and malate, suggesting increased mitochondrial function. Future work includes analysis of mitochondrial morphology via live cell confocal microscopy and of mitochondrial function via metabolic flux analysis on glucose and glutamine metabolism of cells in the PACC state. Our eventual goal is to characterize how cells in the PACC state alter their mitochondrial structure and function to survive therapy. Identifying vulnerabilities of the PACC phenotype will enable new therapeutic approaches to overcome therapy resistance in cancer. Citation Format: Melvin Li, Laurie G. Kostecka, Sarah R. Amend, Kenneth J. Pienta. Stress-induced mitochondrial adaptations in the polyaneuploid cancer cell state. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4842.

Abstract 1690: Myc suppression permits entry into the cancer endocycle to evade toxic effects of chemotherapy

Abstract: Recent advances in precision medicine and immunotherapy have made great strides in cancer treatment and care, but chemoresistance remains a major challenge. One method of chemoresistance employed by cancer cells is accession of the protective polyaneuploid cancer cell (PACC) state, in which cells enter a functionally dormant state upon environmental stress. Entry into the PACC state begins with a whole-genome duplication event followed by endocycling, where the cells are metabolically active and cycling through repeated G1, S and G2 phases of the cell cycle without dividing. While in this state, cells avoid the mitotic stress exerted by common chemotherapeutics and survive therapy, eventually undergoing a depolyploidization process to repopulate the tumor, driving cancer lethality. The mechanisms by which a cancer cell can switch between a mitotic cell cycle and an endocycle are unknown. Cancer is characterized by deregulated cell proliferation, often driven by mutation or amplification of genes that govern the cell cycle. C-myc, an oncogenic transcription factor, is dysregulated in roughly 70% of cancers and is clinically used as a negative prognostic factor for disease-free survival and metastasis. C-myc is responsible for the transcriptional activation of many cell cycle-related genes, and repression of cell cycle inhibitors. Our data indicate that endocycling cells in the PACC state downregulate c-myc expression. Transcriptomic analyses show repression of myc targets, along with supporting protein data that total c-myc protein levels are decreased. While myc downregulation is expected in non-proliferative cells, the compensatory mechanisms mediating the G1/S transition in the cancer endocycle remain unknown. These observations suggest the presence of underlying mechanisms to reprogram the mitotic cell cycle to access the PACC state. We hypothesize that myc downregulation is essential for cells to activate the cancer endocyle and enter the protective PACC state. Understanding the mechanisms that govern this transition is crucial to generate next-generation cancer therapeutics to block accession or disrupt this state. Citation Format: Michael Loycano, Kenneth J. Pienta, Sarah R. Amend. Myc suppression permits entry into the cancer endocycle to evade toxic effects of chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1690.

Baseline PSMA‐PET/CT as a predictor of PSA persistence following radical prostatectomy in high‐risk nonmetastatic prostate cancer patients receiving neoadjuvant therapy

Abstract: The precise staging and proper management of high‐risk prostate cancer (PCa) continues to be a challenge. We aimed to demonstrate the prognostic value of baseline prostate‐specific membrane antigen‐ligand positron emission tomography/computed tomography (PSMA‐PET/CT) in high‐risk, nonmetastatic PCa patients who received neoadjuvant hormonal or chemohormonal treatment followed by radical prostatectomy (RP).

Elucidative ( CLETE ) Binary Classification Platform for 1 Tabular Data 2

Abstract: 13 Therapeutic resistance continues to impede overall survival rates for those affected by cancer. Although driver genes are 14 associated with diverse cancer types, a scarcity of instrumental methods for predicting therapy response or resistance 15 persists. Therefore, the impetus for designing predictive tools for therapeutic response is crucial and tools based on 16 machine learning open new opportunities. Here, we present an easily accessible platform dedicated to Clear, Legible, 17 Explainable, Transparent, and Elucidative (CLETE) yet wholly modifiable binary classification models. Our platform 18 encompasses both unsupervised and supervised feature selection options, hyperparameter search methodologies, under19 sampling and over-sampling methods, and normalization methods, along with fifteen machine learning algorithms. The 20 platform furnishes a k-fold receiver operating curve (ROC) area under the curve (AUC) and accuracy plots, 21 permutation feature importance, SHapley Additive exPlanations (SHAP) plots, and Local Interpretable Model-agnostic 22 Explanations (LIME) plots to interpret the model and individual predictions. We have deployed a unique custom metric 23 for hyperparameter search, which considers both training and validation scores, thus ensuring a check on under or over24 fitting. Moreover, we introduce an innovative scoring method, NegLog2RMSL, which incorporates both training and 25 test scores for model evaluation that facilitates the evaluation of models via multiple parameters. In a bid to simplify the 26 user interface, we provide a graphical interface that sidesteps programming expertise and is compatible with both 27 Windows and Mac OS. Platform robustness has been validated using pharmacogenomic data for 23 drugs across four 28 diseases and holds the potential for utilization with any form of tabular data. 29

Abstract 2205: KRTAP 2-3 is a novel potential biomarker of cells in the polyaneuploid cancer cell (PACC) state to predict cancer recurrence

Abstract: Prostate cancer (PCa) is the second leading cause of death in American men. PCa death is primarily attributed to therapeutic resistance. Our group and others have recently discovered a stress-induced adaptive cell state that plays a key role in therapy resistance: the polyaneuploid cancer cell (PACC) state. Cells in the polyaneuploid cancer cell (PACC) state are characterized by large cell size and polyploidization of the baseline aneuploid genome. Cells in the PACC state (e.g., pleomorphic giant cells, polyploid giant cancer cells, osteoclast like cells) have been reported in patient tumor specimens of multiple cancer types. We recently reported that in primary tumor specimens of PCa patients undergoing radical prostatectomy with curative intent, the number of cells in the PACC state is a statistically significant negative prognostic factor for metastasis-free survival (data adjusted for CAPRA-S). These data highlight the promise of the PACC state as a predictive biomarker for recurrence. In our previous work, cells in the PACC state were identified and quantified through EpCAM immunohistochemistry (IHC) to visualize cell membranes, manually including cells with >3x increased nuclear area compared to adjacent non-polyploid cancer cells. However, this method is labor intensive and highly subjective. There are currently no biomarkers to distinguish cells in the PACC state. To identify candidate PACC state biomarkers, we performed RNA sequencing to identify differentially expressed genes. Across two independent RNA sequencing datasets of PC3 cells induced to enter the PACC state with IC50 cisplatin or IC90 docetaxel, the most differentially expressed gene was KRTAP2-3 (Log2FC=4.3 and 5.51, respectively). The Keratin Associated Protein 2-3 (KRTAP2-3) is encoded by one of the homologous KRTAP genes classified by high sulfur content and is primarily expressed in the cortex of the hair follicle. It has not been previously implicated in PCa or in chemotherapy resistance. Due to its differential RNA expression in the PACC state and its low expression in most normal tissues, we hypothesize that KRTAP2-3 can be used as a biomarker to distinguish cells in the PACC state in patient tumor samples. To test this directly, we optimized RNA in situ-hybridization (RNAish) for KRTAP2-3. In initial experiments utilizing PC3 cell line plugs, we found that the KRTAP2-3 RNAish signal successfully distinguished cells in the PACC state (50.6 average punctae/cell) from non-polyploid cells (0.19 average punctae/cell) reflecting 96% percent accuracy using sensitivity and specificity metrics. We have further confirmed positive KRTAP2-3 signal on PC3 cells induced to access the PACC state in response to cisplatin, docetaxel, and etoposide treatment. Future work will evaluate the utility of the KRTAP2-3 gene as a prognostic biomarker that marks cells in the PACC state within PCa patient tissue microarrays. Citation Format: Sabrina A. Mendez, Reema Sharma, Kenneth J. Pienta, Sarah R. Amend. KRTAP 2-3 is a novel potential biomarker of cells in the polyaneuploid cancer cell (PACC) state to predict cancer recurrence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2205.

MYC-driven increases in mitochondrial DNA copy number occur early and persist throughout prostatic cancer progression

Abstract: Increased mitochondrial function may render some cancers vulnerable to mitochondrial inhibitors. Since mitochondrial function is regulated partly by mitochondrial DNA copy number (mtDNAcn), accurate measurements of mtDNAcn could help reveal which cancers are driven by increased mitochondrial function and may be candidates for mitochondrial inhibition. However, prior studies have employed bulk macrodissections that fail to account for cell type-specific or tumor cell heterogeneity in mtDNAcn. These studies have often produced unclear results, particularly in prostate cancer. Herein, we developed a multiplex in situ method to spatially quantify cell type specific mtDNAcn. We show that mtDNAcn is increased in luminal cells of high-grade prostatic intraepithelial neoplasia (HGPIN), is increased in prostatic adenocarcinomas (PCa), and is further elevated in metastatic castration-resistant prostate cancer. Increased PCa mtDNAcn was validated by two orthogonal methods and is accompanied by increases in mtRNAs and enzymatic activity. Mechanistically, MYC inhibition in prostate cancer cells decreases mtDNA replication and expression of several mtDNA replication genes, and MYC activation in the mouse prostate leads to increased mtDNA levels in the neoplastic prostate cells. Our in situ approach also revealed elevated mtDNAcn in precancerous lesions of the pancreas and colon/rectum, demonstrating generalization across cancer types using clinical tissue samples.

Abstract 4631: Multiplex IHC assay to explore regional heterogeneity of FAP and inflammatory cell density in localized prostatic adenocarcinoma

Abstract: Cancer-associated fibroblasts (CAFs) expressing FAP promote tumor growth, invasion and immune suppression. FAP is a molecular imaging target in cancer and its protease activity is a potential anti-cancer drug target. While FAP expression was associated with biochemical recurrence after prostatectomy using tissue microarrays (TMAs)(DOI:10.1158/2767-9764.CRC-21-0183), its expression has not been comprehensively correlated with morphological features of disease aggressiveness beyond grade. 48 cases of localized prostatic adenocarcinoma were used for a multiplex immunohistochemical assay that included FAP, CD45, CD163, p63 and Keratin 8. Each of these markers were individually optimized by single-plex staining and were then performed as an iterative IHC assay (PMID:35188986) and quantification was performed using the HALO image analysis platform (Indica Labs). We developed a second multiplex assay including FAP, vimentin, smooth muscle actin, desmin, CD31, S100, keratin 8 and p63. FAP IHC staining was analytically validated using a series of positive and negative cell lines. In normal appearing (non-inflamed) prostate regions, FAP expression was negative. By contrast, upregulation of FAP was observed in the stromal compartment in regions of chronic inflammation and some proliferative inflammatory atrophy (PIA) lesions. In tumor regions, only 1 case was totally negative for FAP. Except for 2 cases, in which there was focal weak tumor cell staining, all FAP expression was present in the tumor stromal compartment (TSC). The vast majority of FAP expression was associated with Vim+/Des- fibroblasts, which at times were also positive for SMA (Vim+/Des-/SMA+), indicating they are myofibroblasts. There was very infrequent FAP expression associated with M2 macrophages, endothelial cells, nerves and vimentin-negative smooth muscle cells, indicating that the majority of FAP expression occurs in fibroblasts. Preliminary quantitative data using visual estimations of the fraction of TSC expressing FAP (range, 0-80%, mean=35.8%, median=30%, SD=23.7) was not associated with the overall GS/grade group, but was associated with non-organ confined disease. Furthermore, there was a trend towards increased FAP expression in cases showing intraductal carcinoma and large cribriform formation. Ongoing studies are in process to obtain quantitative data by image analysis and to correlate FAP expression with the presence of overall inflammatory cell density and the density of M2 macrophages. Additionally, we will characterize the cases in terms of molecular features including TMPRSS2-ERG status and PTEN genomic status. Future use of these panels will facilitate studies of associations of FAP with clinical outcome, MRI and PET imaging, response to specific treatments and to help characterize FAP as a predictor of response to emerging FAP inhibitors and FAP-targeted prodrugs. Citation Format: Fernanda Caramella Pereira, Alan K. Meeker, Kenneth Pienta, Qizhi Zheng, Tracy Jones, Srinivasan Yegnasubramanian, Jessica L. Hicks, Sujayita Roy, Angelo M. De Marzo, W. Nathaniel Brennen. Multiplex IHC assay to explore regional heterogeneity of FAP and inflammatory cell density in localized prostatic adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4631.

Abstract 6055: Polyaneuploid cancer cells are metabolically active and utilize lipid droplets to survive toxic stress

Abstract: Over 30,000 men in the U.S. die from metastatic prostate cancer each year. Metastatic cancer remains incurable as a population of cancer cells within a tumor are resistant to all known therapies. Despite decades of research, the source of therapeutic resistance is still unknown. We have identified the polyaneuploid cancer cell (PACC) state as a chemo-resistant cell state that is associated with therapeutic resistance. Cells in the PACC state are large in size, have high genomic content, and represent the majority cell state following high dose chemotherapy in vitro. While the PACC state has been documented in patient samples of many cancer types, including prostate cancer where it is associated with progression, the survival mechanisms that enable the PACC state remain largely undefined. We discovered that cells in the PACC state are highly metabolically active and contain a higher number of lipid droplets (LDs) than the non-polyploid parental cells they are derived from. LDs act as central anti-lipotoxic organelles and sequestration of toxic moieties into LDs allows for lower lipotoxicity in cells and higher chances of survival and future proliferation. Higher levels of LDs are associated with increased tumor aggressiveness and chemotherapy resistance. We found that PLIN1 (an exclusive LD surface protein), and DGAT1 (an enzyme that catalyzes the generation of TAG, which is the main component of LDs) are expressed at higher levels in the tumors of prostate cancer patients with lower disease-free survival and higher Gleason score. This indicates that aggressive prostate cancer is most likely associated with high levels of LDs. We hypothesize that cells entering the PACC state survive chemotherapeutic stress by having an elevated metabolism and sequestering toxic lipids into LDs to enhance cell survival. Metabolomic and lipidomic data demonstrate that PACCs have a highly active TCA cycle and higher overall lipids in multiple classes compared to the parental cells they are derived from. Additionally, utilizing flow cytometry and imaging, we found that LDs form in cells accessing the PACC state as early as three hours post chemotherapy treatment, suggesting a crucial role for avoiding lipotoxicity. We also observed low levels of HSL (a rate limiting enzyme in lipolysis) in the PACC state indicating that after PACCs form LDs they do not immediately break them down, another possible mechanism of avoiding lipotoxicity. We have shown this in four cancer cell lines from two tumor types (Prostate cancer: PC3, DU145, and LNCaP. Breast cancer: MDA-MB-231) with three classes of chemotherapies (cisplatin, docetaxel, etoposide), proving the observed phenotype is not specific to any one cell line, tumor type, or drug class. Our future work will focus on inhibiting lipid droplet formation in vivo and in vitro to increase cellular lipotoxicity in the PACC state to induce cancer cell death. Citation Format: Laurie Gayle Kostecka, Anne Le, Sarah Amend, Kenneth J. Pienta. Polyaneuploid cancer cells are metabolically active and utilize lipid droplets to survive toxic stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6055.

Novel urinary tract obstruction marker discovery by multi-marker profiling of urinary extracellular vesicles derived from a rat UTO model.

Abstract: 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. RESULTS While mRNA hierarchical clustering of urinary sEVs was unable to differentiate upper compared to lower tract urinary obstruction, clustering was able to detect overall disease state (UUTO or LUTO) versus healthy controls. Further, urinary sEVs carried genes unique to each treatment group (UUTO: 59 genes, LUTO: 17 genes), while only one gene was uniquely carried in the control group. Notable genes of interest found in urinary sEVs were VCAM-1 and NOS1 for UUTO, Egfr for LUTO, and Pck1 for healthy controls. CONCLUSION This study provides support that differential gene expression of urinary sEV mRNA has potential to act as biomarkers in the diagnosis and prognosis of UTO. Urinary sEVs demonstrated higher numbers of unique genes representative of injury to the kidney than that of injury to the bladder. Importantly, there were genes unique to UUTO sEVs, indicating the extent and reversibility of renal damage can be independent of the function, damage, and architecture of the bladder.

Modeling cancer’s ecological and evolutionary dynamics

Abstract: Abstract In this didactic paper, we present a theoretical modeling framework, called the G -function, that integrates both the ecology and evolution of cancer to understand oncogenesis. The G -function has been used in evolutionary ecology, but has not been widely applied to problems in cancer. Here, we build the G -function framework from fundamental Darwinian principles and discuss how cancer can be seen through the lens of ecology, evolution, and game theory. We begin with a simple model of cancer growth and add on components of cancer cell competition and drug resistance. To aid in exploration of eco-evolutionary modeling with this approach, we also present a user-friendly software tool. By the end of this paper, we hope that readers will be able to construct basic G function models and grasp the usefulness of the framework to understand the games cancer plays in a biologically mechanistic fashion.

Bone marrow niche chemoprotection of metastatic solid tumors mediated by CYP3A4

Abstract: The bone/bone marrow is one of the most common sites for metastatic solid tumors. Moreover, the tumor microenvironment is an essential part of cancer homeostasis. Previously, it was shown that cytochrome P450 enzymes (CYPs) are present in the bone marrow (BM) microenvironment, particularly in the mesenchymal stroma cells, at levels comparable to those of hepatocytes. It was found that the CYPs play important roles in nurturing and maintaining normal hematopoietic stem cells as well as multiple myeloma and leukemia cells, including protecting them from toxic insults. It was hypothesized that the CYPs in the BM microenvironment might play a similar role in solid tumors metastatic to bone.

Prognostic impact of circulating tumor cells in oligometastatic hormone-sensitive prostate cancer following metastasis-directed therapy.

Abstract: 199 Background: Contained within the spectrum of metastatic cancer is an oligometastatic state where metastases are limited in number. Recent prospective data have shown that metastasis directed therapy (MDT) can alter the natural history of oligometastatic disease. In hormone-sensitive prostate cancer (HSPC), the positive clinical effect of MDT has been observed by the phase II STOMP and ORIOLE trials. Circulating tumor cells (CTCs) are a likely origin of the formation of macroscopic metastases. CTCs thus may provide an approach for identifying subgroups of patients with oligometastatic HSPC (oligoHSPC) that would benefit most from MDT. Our main goal was to evaluate the association between presence of CTCs at baseline or day 180 with clinical outcomes in the ORIOLE trial. Methods: ORIOLE was a phase II trial randomizing men with recurrent oligoHSPC with 1-3 metastases to observation (Obs) versus stereotactic ablative radiotherapy (SABR) MDT. Blood samples were prospectively collected at baseline and day 180. Progression-free survival (PFS) was a composite endpoint including any of the following: a PSA rise of at least 2 ng/dL and 25% above nadir; radiologic progression by CT, MRI or bone scan (RECIST v1.1); symptomatic progression of disease; initiation of ADT; or death. Patient blood samples were shipped for analysis on Epic Sciences liquid biopsy platform (Epic Sciences, San Diego, CA). Machine learning algorithms identified CTCs and characterized androgen receptor (AR) expression. Comparisons of patient and tumor characteristics between the groups were performed by two-sample t-tests. Survival curves were generated using the Kaplan-Meier method and p-values were calculated using log-rank test. Analysis was performed using SPSS version 28. Results: A total of 82 samples were collected: 70 from the SABR arm (35 baseline and 35 on day 180) and 12 Obs (7 baseline and 5 on day 180). CTCs were detected in 30/42 samples at baseline (71%, AR+= 7) and in 26/40 samples on day 180 (65%, AR+= 9). In the SABR group there was no difference between CTC+ versus CTC- and AR + versus AR- groups for PSA evaluated at baseline, day 90 or day 180 or Gleason score. With a median follow-up of 41.7 months, PFS was significantly lower in the patients with AR+ versus AR- CTCs at baseline in the SABR arm (p = 0.011, mean PFS: AR+ = 9.3 months, AR- = 27.1 months). The mean biochemical failure-free survival was AR+= 12.9 versus AR-= 29.2 months (p = 0.058). Conclusions: Our preliminary results demonstrate an association between AR+ CTCs at baseline and Day 180 with clinical outcomes following SABR MDT in oligoHSPC. This is the first report examining baseline and dynamic presence of CTCs in oligoHSPC treated from a prospective randomized trial of SABR. Longer follow-up, further analysis and a greater number of patients are needed for a more comprehensive conclusion.