One of the most formidable challenges in oncology and tumor biology research is to provide an accurate understanding of tumor dormancy mechanisms. Dormancy refers to the ability of tumor cells to go ...undetected in the body for a prolonged period, followed by “spontaneous” escape. Various models of dormancy have been postulated, including angiogenic, immune-mediated, and cellular dormancy. While the former two propose mechanisms by which tumor growth may remain static at a population level, cellular dormancy refers to molecular processes that restrict proliferation at the cell level. Senescence is a form of growth arrest, during which cells undergo distinct phenotypic, epigenetic, and metabolic changes. Senescence is also associated with the development of a robust secretome, comprised of various chemokines and cytokines that interact with the surrounding microenvironment, including other tumor cells, stromal cells, endothelial cells, and immune cells. Both tumor and non-tumor cells can undergo senescence following various stressors, many of which are present during tumorigenesis and therapy. As such, senescent cells are present within forming tumors and in residual tumors post-treatment and therefore play a major role in tumor biology. However, the contributions of senescence to dormancy are largely understudied. Here, we provide an overview of multiple processes that have been well established as being involved in tumor dormancy, and we speculate on how senescence may contribute to these mechanisms.
Tumor dormancy leading to cancer relapse is still a poorly understood mechanism. Several cell states such as quiescence and diapause can explain the persistence of tumor cells in a dormant state, but ...the potential role of tumor cell senescence has been met with hesitance given the historical understanding of the senescent growth arrest as irreversible. However, recent evidence has suggested that senescence might contribute to dormancy and relapse, although its exact role is not fully developed. This limited understanding is largely due to the paucity of reliable study models. The current 2D cell modeling is overly simplistic and lacks the appropriate representation of the interactions between tumor cells (senescent or non-senescent) and the other cell types within the tumor microenvironment (TME), as well as with the extracellular matrix (ECM). 3D cell culture models, including 3D bioprinting techniques, offer a promising approach to better recapitulate the native cancer microenvironment and would significantly improve our understanding of cancer biology and cellular response to treatment, particularly Therapy-Induced Senescence (TIS), and its contribution to tumor dormancy and cancer recurrence. Fabricating a novel 3D bioprinted model offers excellent opportunities to investigate both the role of TIS in tumor dormancy and the utility of senolytics (drugs that selectively eliminate senescent cells) in targeting dormant cancer cells and mitigating the risk for resurgence. In this review, we discuss literature on the possible contribution of TIS in tumor dormancy, provide examples on the current 3D models of senescence, and propose a novel 3D model to investigate the ultimate role of TIS in mediating overall response to therapy.
•Therapy-Induced Senescence (TIS) is a major component of tumor cell response to therapy.•TIS might be a potential mechanism for tumor dormancy•3D bioprinting is an advantageous approach to investigate the role of TIS in tumor dormancy•3D bioprinting provides an avenue to screen for more effective senolytics for cancer therapy
Canine malignant melanoma, a significant cause of mortality in domestic dogs, is a powerful comparative model for human melanoma, but little is known about its genetic etiology. We mapped the genomic ...landscape of canine melanoma through multi-platform analysis of 37 tumors (31 mucosal, 3 acral, 2 cutaneous, and 1 uveal) and 17 matching constitutional samples including long- and short-insert whole genome sequencing, RNA sequencing, array comparative genomic hybridization, single nucleotide polymorphism array, and targeted Sanger sequencing analyses. We identified novel predominantly truncating mutations in the putative tumor suppressor gene PTPRJ in 19% of cases. No BRAF mutations were detected, but activating RAS mutations (24% of cases) occurred in conserved hotspots in all cutaneous and acral and 13% of mucosal subtypes. MDM2 amplifications (24%) and TP53 mutations (19%) were mutually exclusive. Additional low-frequency recurrent alterations were observed amidst low point mutation rates, an absence of ultraviolet light mutational signatures, and an abundance of copy number and structural alterations. Mutations that modulate cell proliferation and cell cycle control were common and highlight therapeutic axes such as MEK and MDM2 inhibition. This mutational landscape resembles that seen in BRAF wild-type and sun-shielded human melanoma subtypes. Overall, these data inform biological comparisons between canine and human melanoma while suggesting actionable targets in both species.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Glioblastoma (GBM) remains one of the most lethal forms of cancer due, in part, to the capacity of tumor cells to persist during therapy and then recover. Understanding how these residual ...tumor cells survive is therefore imperative to developing more effective treatment strategies. We have demonstrated that GBM cells, including those from patient-derived xenografts, undergo a state of therapy-induced senescence (TIS) rather than cell death following temozolomide (TMZ) and radiation (IR). Both TMZ and IR treatment at physiologically relevant doses result in elevated senescence-associated-β-galactosidase, altered morphology, p21 induction, and increased expression of the senescence-associated-heterochromatic-foci marker H3K9Me3. Further, despite TIS-induction in a majority of the residual cells post-treatment, GBM viable cell number increases after a prolonged stasis, indicating that populations are capable of reentering a proliferative state. However, our current understanding of how the tumor microenvironment influences this growth arrest and subsequent proliferative recovery is underdeveloped. We aim to bridge that gap by investigating the paracrine communications between astrocytes and GBM cells undergoing IR-induced senescence in order to identify how these interactions foster disease progression. Current studies are focused on evaluating the effect of astrocytes on the induction and durability of TIS in GBM cells. Proteomic studies will be pursued to characterize the secretome of astrocyte-GBM co-cultures and identify factors that drive GBM senescent response to IR. Finally, based on preliminary data demonstrating that normal astrocytes are also damaged by IR, we will undertake mechanistic studies to understand how cell-intrinsic events within the astrocyte population drive extrinsic-influence on GBM cells. We anticipate that these identified signaling events may serve as potential therapeutic targets.
Citation Format: Valerie DeLuca, Priya Digumarti, Michael E. Berens. Deciphering tumor recurrence post-therapy: Interactions between the tumor microenvironment and therapy-induced senescent glioblastoma. 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 4794.
Genomic analyses of cutaneous melanoma (CM) have yielded biological and therapeutic insights, but understanding of non-ultraviolet (UV)-derived CMs remains limited. Deeper analysis of acral ...lentiginous melanoma (ALM), a rare sun-shielded melanoma subtype associated with worse survival than CM, is needed to delineate non-UV oncogenic mechanisms. We thus performed comprehensive genomic and transcriptomic analysis of 34 ALM patients. Unlike CM, somatic alterations were dominated by structural variation and absence of UV-derived mutation signatures. Only 38% of patients demonstrated driver
mutations. In contrast with CM, we observed
copy gains in 15% of patients, and somatic
translocations, copy gains, and missense and promoter mutations, or germline events, in 41% of patients. We further show that in vitro TERT inhibition has cytotoxic effects on primary ALM cells. These findings provide insight into the role of
in ALM tumorigenesis and reveal preliminary evidence that TERT inhibition represents a potential therapeutic strategy in ALM.
Abstract
Development of a non-invasive test that can measure drug delivery and target engagement in GBM represents an opportunity to enhance knowledge during early phase clinical trials of a new ...compound’s pharmacological suitability and potential efficacy. We present here data supporting that the cargo within extracellular vesicles (EV) can potentially serve as a liquid biopsy that reports on the pharmacodynamics of GBM therapeutics. We treated short-term PDX cultures with vehicle, temozolomide, MLN4924, or arsenic trioxide. EVs were isolated from culture supernatants using size exclusion chromatography and then analyzed by mass spectrometry (proteomics) and RNA sequencing to characterize and compare cargo profiles for each condition. We found that at the proteome level, FDFT1 and FARSB were detected only in temozolomide EVs across all cell lines. In addition, there were drug-agnostic indications of exposure, including decreased abundance in all treated EV conditions of SLC3A2, C3, PLG, and A1BG, and increased abundance of GSTP1. These cargo changes were further validated by western blotting and ExoView immunofluorescence on isolated EVs. At the EV-transcriptome level, depending on treatment, there were shared alterations in EV cargo between models in the expression of long non-coding RNAs, genes that are overrepresented in biological processes such as cytoplasmic translation and cellular macromolecule biosynthesis, and circular RNAs. Thus, these results indicate that EV cargo post-treatment may be a novel pharmacodynamic reporter in GBM. To allow immunoprecipitation of patient GBM-derived EVs with the selective interrogation, the potential biomarkers, including PTPRZ1, B7H3, IL13RA2, and EGFR were screened across isolated EVs from both pre-clinical and clinical patient samples. Future efforts are focused on evaluating immunoprecipitated GBM-EVs from longitudinally collected patient biofluids. Overall, we anticipate that the results of this study will lead to development of a clinical test that reflects BBB penetration and tumor response, which will likely aid in novel drug development efforts.
Abstract The recalcitrant nature of glioblastoma (GBM) may be due, in part, to the promotion of therapy-induced senescence (TIS) by standard of care treatments. TIS is a prolonged growth arrest ...associated with epigenetic, metabolic, and biochemical alterations, as well as a robust secretory phenotype. Despite an initial period of tumor stasis due to the loss of cell proliferation, TIS is associated with the development of stemness, increased drug resistance, and immune suppression. Our preliminary data demonstrate the prominent induction of TIS in GBM tumor cells and astrocytes following standard of care therapies for GBM in vitro. However, studies of TIS in GBM patients have been limited due to i) the impracticality of receiving multiple GBM biopsies post-treatment but prior to recurrence and ii) the lack of robust detection methods for TIS even with appropriate biopsy. These challenges argue the need for novel methods to survey TIS in patients. Extracellular vesicles (EVs) are small membrane-bound particles that readily cross the blood brain barrier, and convey information about originating cell identity and cell state through their cargo content. We hypothesize that TIS in host and tumor cells drives the elaboration of senescence-associated EVs (senEVs) with quantifiable senescence protein cargo signatures, and consequently, that EVs can serve as a liquid biopsy for senescence in patients. In a preliminary experiment, two patient derived xenografts grown as short-term in vitro cultures were exposed to 6GY irradiation, with supernatant collected prior to radiation (D0), at peak senescence (D7), and at late senescence (D10). EVs were isolated and subjected to unbiased mass spectrometry. Following unsupervised clustering, EVs were grouped by treatment rather than by cell line. Approximately 6000 proteins were identified across the entire data set, with 105 proteins unique to D7 samples, 162 proteins unique to D10 samples, and 688 proteins exclusive to D7 and D10 samples. Further, proteins from two established senescence gene sets were identified as unique to the D7 and/or D10 conditions. Current work to more robustly identify enrichment of senescence gene sets in EV cargo post-irradiation is underway. We have also established shRNA knockdown cell lines with abrogated TIS to equip validation studies of the TIS-EV cargo relationship. We anticipate that these studies will aid in the development of EVs as a novel reporter of senescence in the clinic. Citation Format: Valerie DeLuca, Priya Digumarti, Krystine Garcia-Mansfield, Patrick Pirrotte, Michael E. Berens. Signatures of therapy-induced senescence in glioblastoma-derived extracellular vesicles abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2959.
Abstract The selectivity of the blood-brain-barrier (BBB) can prevent therapeutics from reaching the brain, and this may contribute to the high failure rate of new drugs for tumors like glioblastoma ...(GBM) and brain metastasis. The capacity to detect BBB penetrance in real-time in a noninvasive manner would arguably aid the rate of therapeutic development. Extracellular vesicles, which are membrane bound particles secreted by all cell types in the body, have potential as a neuro pharmacodynamic reporter given that their protein and RNA cargo reflect the originating cell population. We hypothesized that the exposure of GBM cells to therapy results in altered EV cargo, and that the detection of this shift can be leveraged as a liquid biopsy from patients during early clinical trials to determine BBB penetrance and tumor engagement. To identify cargo shifts indicative of treatment, we exposed four short-term patient derived glioma cell lines to arsenic trioxide (an idiopathic toxin), MLN4924 (a neddylation inhibitor), and the alkylating agent temozolomide, then harvested EVs for unbiased mass spectrometry and RNA sequencing. Interestingly, we identified conserved upregulated and downregulated protein and RNA species across cell lines and across drug treatments, despite the diverse mechanisms of action. Candidate proteins were further validated by mesoscale immunoassays and exoview evaluation of tetraspanin-captured EVs. RNA species were validated by qRT-PCR. Overall, we demonstrate that GBM-derived EV cargo changes in response to therapy, supporting the development of EVs as a reporter of drug delivery in GBM. Ongoing and future work is focused on identifying enrichment handles in order to selectively evaluate GBM-derived EV cargo from patient biofluids. Thus far, B7H3, PTPRZ1, EGFRvII and IL13Ra2 have been screened as putative handles. Success in this pursuit could substantially enhance findings and accelerate drug testing in early-stage clinical trials in brain tumor patients by reporting drug accessibility to the tumor and engagement with drug targets. Citation Format: Valerie DeLuca, Nanyun Tang, Nathaniel Hansen, Anjali Raju, Charles Shaffer, Yue Hao, Terry C. Burns, Jann N. Sarkaria, Ian Parney, Patrick Pirrotte, Kendall Van Keuren-Jensen, Michael E. Berens. Glioblastoma-derived extracellular vesicle cargo as a reporter of drug delivery and effect abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2130.
Abstract
Glioblastoma (GBM), a lethal astrocytic brain tumor, has limited available treatment options. A major hindrance to the progress of new therapies is the selectivity of the blood brain barrier ...(BBB) which limits drug access to the tumor. Further, there are currently no minimally-invasive tests that can quickly and accurately determine whether novel therapeutics have crossed the BBB during clinical trials. Therefore, development of a non-invasive test that can identify drug delivery and target engagement in GBM represents an opportunity to enhance knowledge during early phase trials of a new compound’s pharmacological suitability and potential efficacy. This study proposes that cargo contained in GBM-derived extracellular vesicles (EVs), which are small membrane-bound particles released from cells, may serve as one such pharmacodynamic reporter. We analyzed RNA-seq data for EVs isolated from two GBM patient-derived xenograft models grown as short-term in vitro cultures, GBM10 and GBM120, following treatment with either temozolomide (TMZ) or pevonedistat (MLN). We assessed whether EV RNA payloads vary with different drug concentrations (EC50 vs EC80) and at different time points (4hr vs 24hr) post treatment. In the samples treated with MLN, a few long non-coding RNAs are commonly upregulated across the different time points and two models. Under different TMZ concentrations, differentially expressed genes are overrepresented in biological processes such as cytoplasmic translation and cellular macromolecule biosynthesis. We also found a negative correlation between the TMZ concentration and Y RNA expression level, which are functionally involved with DNA replication. Additionally, using CIRI2, we predicted the amount of circular RNAs in the EV cargo; we found that the ratio of circular RNAs to their linear counterparts (CLR) varies under different treatments. In GBM10, the percentage of circRNA with CLR > 1 decreases with increasing drug effect. Thus, our preliminary results indicate that EV cargo post-treatment may be a novel pharmacodynamic reporter in GBM. To apply such an assessment to patients, we have simultaneously pursued the development of an immunoprecipitation (IP) approach to enrich GBM-derived EVs that can then undergo cargo profiling. Potential biomarkers were screened across isolated GBM EVs from in vitro supernatant by western blot and ExoView analysis. B7H3 has emerged as a lead candidate for GBM-EV enrichment. To validate the ability of EV cargo to reflect drug distribution across the BBB in patients, current efforts are focused on applying IP enrichment of GBM-EVs in longitudinally-acquired cerebrospinal fluid samples from patients during their disease course. Overall, we anticipate that the results of this study will lead to development of a clinical test that reflects BBB penetration and tumor response, which will likely aid in novel drug development efforts.
Citation Format: Valerie DeLuca, Nanyun Tang, Yue Hao, Anjali Raju, Charles Shaffer, Cecile Riviere-Cazaux, Terry C. Burns, Jann Sarkaria, Ian Parney, Patrick Pirrotte, Kendall Van Keuren-Jensen, Michael E. Berens. Extracellular vesicles as a pharmacodynamic reporter in glioblastoma 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 2788.
Developing the Technology-Integrated Assessment Framework Madland, Colin; Irvine, Valerie; DeLuca, Chris ...
The Open/Technology in Education, Society, and Scholarship Association Journal,
05/2024, Letnik:
4, Številka:
1
Journal Article
Odprti dostop
The purpose of this paper is to describe the development of a new framework for understanding technology-integrated assessment in higher education based on a review of the literature using the ...assessment design in a digital world framework (Bearman et al., 2022) as a lens. Our review (Madland et al., 2024) revealed both congruities and incongruities between the literature and the framework, leading to the need for further work to accurately conceptualize technology-integrated assessment. In this article, we contribute to the literature on technology-integrated assessment in higher education by proposing the technology-integrated assessment framework. This paper marks an important step in extending our understanding of the factors influencing instructors who integrate technology into their assessment practice and promoting ethical and equitable approaches to technology-integrated assessment in higher education.
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