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1.
J Cell Physiol ; 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38775127

RESUMEN

Primary, glioblastoma, and secondary brain tumors, from metastases outside the brain, are among the most aggressive and therapeutically resistant cancers. A physiological barrier protecting the brain, the blood-brain barrier (BBB), functions as a deterrent to effective therapies. To enhance cancer therapy, we developed a cancer terminator virus (CTV), a unique tropism-modified adenovirus consisting of serotype 3 fiber knob on an otherwise Ad5 capsid that replicates in a cancer-selective manner and simultaneously produces a potent therapeutic cytokine, melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24). A limitation of the CTV and most other viruses, including adenoviruses, is an inability to deliver systemically to treat brain tumors because of the BBB, nonspecific virus trapping, and immune clearance. These obstacles to effective viral therapy of brain cancer have now been overcome using focused ultrasound with a dual microbubble treatment, the focused ultrasound-double microbubble (FUS-DMB) approach. Proof-of-principle is now provided indicating that the BBB can be safely and transiently opened, and the CTV can then be administered in a second set of complement-treated microbubbles and released in the brain using focused ultrasound. Moreover, the FUS-DMB can be used to deliver the CTV multiple times in animals with glioblastoma  growing in their brain thereby resulting in a further enhancement in survival. This strategy permits efficient therapy of primary and secondary brain tumors enhancing animal survival without promoting harmful toxic or behavioral side effects. Additionally, when combined with a standard of care therapy, Temozolomide, a further increase in survival is achieved. The FUS-DMB approach with the CTV highlights a noninvasive strategy to treat brain cancers without surgery. This innovative delivery scheme combined with the therapeutic efficacy of the CTV provides a novel potential translational therapeutic approach for brain cancers.

2.
Acta Neuropathol Commun ; 12(1): 40, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38481314

RESUMEN

DNA methylation is crucial for chromatin structure and gene expression and its aberrancies, including the global "hypomethylator phenotype", are associated with cancer. Here we show that an underlying mechanism for this phenotype in the large proportion of the highly lethal brain tumor glioblastoma (GBM) carrying receptor tyrosine kinase gene mutations, involves the mechanistic target of rapamycin complex 2 (mTORC2), that is critical for growth factor signaling. In this scenario, mTORC2 suppresses the expression of the de novo DNA methyltransferase (DNMT3A) thereby inducing genome-wide DNA hypomethylation. Mechanistically, mTORC2 facilitates a redistribution of EZH2 histone methyltransferase into the promoter region of DNMT3A, and epigenetically represses the expression of DNA methyltransferase. Integrated analyses in both orthotopic mouse models and clinical GBM samples indicate that the DNA hypomethylator phenotype consistently reprograms a glutamate metabolism network, eventually driving GBM cell invasion and survival. These results nominate mTORC2 as a novel regulator of DNA hypomethylation in cancer and an exploitable target against cancer-promoting epigenetics.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Ratones , Animales , Glioblastoma/patología , Línea Celular Tumoral , Diana Mecanicista del Complejo 2 de la Rapamicina/genética , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Metilación de ADN , Fenotipo , Neoplasias Encefálicas/patología , ADN/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismo , Proteínas Tirosina Quinasas/genética
3.
Proc Natl Acad Sci U S A ; 120(45): e2307094120, 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37922327

RESUMEN

Bone metastasis is a frequent and incurable consequence of advanced prostate cancer (PC). An interplay between disseminated tumor cells and heterogeneous bone resident cells in the metastatic niche initiates this process. Melanoma differentiation associated gene-9 (mda-9/Syntenin/syndecan binding protein) is a prometastatic gene expressed in multiple organs, including bone marrow-derived mesenchymal stromal cells (BM-MSCs), under both physiological and pathological conditions. We demonstrate that PDGF-AA secreted by tumor cells induces CXCL5 expression in BM-MSCs by suppressing MDA-9-dependent YAP/MST signaling. CXCL5-derived tumor cell proliferation and immune suppression are consequences of the MDA-9/CXCL5 signaling axis, promoting PC disease progression. mda-9 knockout tumor cells express less PDGF-AA and do not develop bone metastases. Our data document a previously undefined role of MDA-9/Syntenin in the tumor and microenvironment in regulating PC bone metastasis. This study provides a framework for translational strategies to ameliorate health complications and morbidity associated with advanced PC.


Asunto(s)
Neoplasias Óseas , Melanoma , Neoplasias de la Próstata , Masculino , Humanos , Sinteninas/genética , Sinteninas/metabolismo , Melanoma/metabolismo , Neoplasias de la Próstata/genética , Transducción de Señal/genética , Neoplasias Óseas/genética , Línea Celular Tumoral , Microambiente Tumoral , Metástasis de la Neoplasia
4.
Elife ; 122023 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-36645410

RESUMEN

Background: We have previously shown that the long non-coding (lnc)RNA prostate cancer associated 3 (PCA3; formerly prostate cancer antigen 3) functions as a trans-dominant negative oncogene by targeting the previously unrecognized prostate cancer suppressor gene PRUNE2 (a homolog of the Drosophila prune gene), thereby forming a functional unit within a unique allelic locus in human cells. Here, we investigated the PCA3/PRUNE2 regulatory axis from early (tumorigenic) to late (biochemical recurrence) genetic events during human prostate cancer progression. Methods: The reciprocal PCA3 and PRUNE2 gene expression relationship in paired prostate cancer and adjacent normal prostate was analyzed in two independent retrospective cohorts of clinically annotated cases post-radical prostatectomy: a single-institutional discovery cohort (n=107) and a multi-institutional validation cohort (n=497). We compared the tumor gene expression of PCA3 and PRUNE2 to their corresponding expression in the normal prostate. We also serially examined clinical/pathological variables including time to disease recurrence. Results: We consistently observed increased expression of PCA3 and decreased expression of PRUNE2 in prostate cancer compared with the adjacent normal prostate across all tumor grades and stages. However, there was no association between the relative gene expression levels of PCA3 or PRUNE2 and time to disease recurrence, independent of tumor grades and stages. Conclusions: We concluded that upregulation of the lncRNA PCA3 and targeted downregulation of the protein-coding PRUNE2 gene in prostate cancer could be early (rather than late) molecular events in the progression of human prostate tumorigenesis but are not associated with biochemical recurrence. Further studies of PCA3/PRUNE2 dysregulation are warranted. Funding: We received support from the Human Tissue Repository and Tissue Analysis Shared Resource from the Department of Pathology of the University of New Mexico School of Medicine and a pilot award from the University of New Mexico Comprehensive Cancer Center. RP and WA were supported by awards from the Levy-Longenbaugh Donor-Advised Fund and the Prostate Cancer Foundation. EDN reports research fellowship support from the Brazilian National Council for Scientific and Technological Development (CNPq), Brazil, and the Associação Beneficente Alzira Denise Hertzog Silva (ABADHS), Brazil. This work has been funded in part by the NCI Cancer Center Support Grants (CCSG; P30) to the University of New Mexico Comprehensive Cancer Center (CA118100) and the Rutgers Cancer Institute of New Jersey (CA072720).


Asunto(s)
Neoplasias de la Próstata , ARN Largo no Codificante , Humanos , Masculino , Antígenos de Neoplasias/genética , Biomarcadores de Tumor/genética , Recurrencia Local de Neoplasia/genética , Próstata/metabolismo , Neoplasias de la Próstata/metabolismo , Estudios Retrospectivos , ARN Largo no Codificante/genética
5.
Proc Natl Acad Sci U S A ; 119(47): e2213835119, 2022 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-36395141

RESUMEN

Somatic copy number alterations (SCNAs), generally (1) losses containing interferons and interferon-pathway genes, many on chromosome 9p, predict immune-cold, immune checkpoint therapy (ICT)-resistant tumors (2); however, genomic regions mediating these effects are unclear and probably tissue specific. Previously, 9p21.3 loss was found to be an early genetic driver of human papillomavirus-negative (HPV-) head and neck squamous cancer (HNSC), associated with an immune-cold tumor microenvironment (TME) signal, and recent evidence suggested that this TME-cold phenotype was greatly enhanced with 9p21 deletion size, notably encompassing band 9p24.1 (3). Here, we report multi-omic, -threshold and continuous-variable dissection of 9p21 and 9p24 loci (including depth and degree of somatic alteration of each band at each locus, and each gene at each band) and TME of four HPV- HNSC cohorts. Preferential 9p24 deletion, CD8 T-cell immune-cold associations were observed, driven by 9p24.1 loss, and in turn by an essential telomeric regulatory gene element, JAK2-CD274. Surprisingly, same genetic region gains were immune hot. Related 9p21-TME analyses were less evident. Inherent 9p-band-level influences on anti-PD1 ICT survival rates, coincident with TME patterns, were also observed. At a 9p24.1 whole-transcriptome expression threshold of 60th percentile, ICT survival rate exceeded that of lower expression percentiles and of chemotherapy; below this transcript threshold, ICT survival was inferior to chemotherapy, the latter unaffected by 9p24.1 expression level (P-values < 0.01, including in a PD-L1 immunohistochemistry-positive patient subgroup). Whole-exome analyses of 10 solid-tumor types suggest that these 9p-related ICT findings could be relevant to squamous cancers, in which 9p24.1 gain/immune-hot associations exist.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Infecciones por Papillomavirus , Humanos , Microambiente Tumoral/genética , Inhibidores de Puntos de Control Inmunológico , Infecciones por Papillomavirus/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/genética
6.
Cancer Sci ; 113(5): 1555-1563, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35271755

RESUMEN

Cancer cells depend on metabolic reprogramming for survival, undergoing profound shifts in nutrient sensing, nutrient uptake and flux through anabolic pathways, in order to drive nucleotide, lipid, and protein synthesis and provide key intermediates needed for those pathways. Although metabolic enzymes themselves can be mutated, including to generate oncometabolites, this is a relatively rare event in cancer. Usually, gene amplification, overexpression, and/or downstream signal transduction upregulate rate-limiting metabolic enzymes and limit feedback loops, to drive persistent tumor growth. Recent molecular-genetic advances have revealed discrete links between oncogenotypes and the resultant metabolic phenotypes. However, more comprehensive approaches are needed to unravel the dynamic spatio-temporal regulatory map of enzymes and metabolites that enable cancer cells to adapt to their microenvironment to maximize tumor growth. Proteomic and metabolomic analyses are powerful tools for analyzing a repertoire of metabolic enzymes as well as intermediary metabolites, and in conjunction with other omics approaches could provide critical information in this regard. Here, we provide an overview of cancer metabolism, especially from an omics perspective and with a particular focus on the genomically well characterized malignant brain tumor, glioblastoma. We further discuss how metabolomics could be leveraged to improve the management of patients, by linking cancer cell genotype, epigenotype, and phenotype through metabolic reprogramming.


Asunto(s)
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Carcinogénesis/genética , Transformación Celular Neoplásica/genética , Glioma/genética , Glioma/metabolismo , Humanos , Metabolómica , Proteómica , Microambiente Tumoral
7.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-34016751

RESUMEN

Melanoma differentiation associated gene-9 (MDA-9), Syntenin-1, or syndecan binding protein is a differentially regulated prometastatic gene with elevated expression in advanced stages of melanoma. MDA-9/Syntenin expression positively associates with advanced disease stage in multiple histologically distinct cancers and negatively correlates with patient survival and response to chemotherapy. MDA-9/Syntenin is a highly conserved PDZ-domain scaffold protein, robustly expressed in a spectrum of diverse cancer cell lines and clinical samples. PDZ domains interact with a number of proteins, many of which are critical regulators of signaling cascades in cancer. Knockdown of MDA-9/Syntenin decreases cancer cell metastasis, sensitizing these cells to radiation. Genetic silencing of MDA-9/Syntenin or treatment with a pharmacological inhibitor of the PDZ1 domain, PDZ1i, also activates the immune system to kill cancer cells. Additionally, suppression of MDA-9/Syntenin deregulates myeloid-derived suppressor cell differentiation via the STAT3/interleukin (IL)-1ß pathway, which concomitantly promotes activation of cytotoxic T lymphocytes. Biologically, PDZ1i treatment decreases metastatic nodule formation in the lungs, resulting in significantly fewer invasive cancer cells. In summary, our observations indicate that MDA-9/Syntenin provides a direct therapeutic target for mitigating aggressive breast cancer and a small-molecule inhibitor, PDZ1i, provides a promising reagent for inhibiting advanced breast cancer pathogenesis.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Interleucina-1beta/genética , Neoplasias Pulmonares/tratamiento farmacológico , Oxadiazoles/farmacología , Pirimidinas/farmacología , Sinteninas/genética , Animales , Antineoplásicos/síntesis química , Neoplasias de la Mama/genética , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Línea Celular Tumoral , Quimiocina CCL11/genética , Quimiocina CCL11/inmunología , Quimiocina CCL17/genética , Quimiocina CCL17/inmunología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-1alfa/genética , Interleucina-1alfa/inmunología , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/inmunología , Subunidad p19 de la Interleucina-23/genética , Subunidad p19 de la Interleucina-23/inmunología , Interleucina-5/genética , Interleucina-5/inmunología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/secundario , Ratones , Ratones Endogámicos BALB C , Oxadiazoles/síntesis química , Pirimidinas/síntesis química , Transducción de Señal , Sinteninas/antagonistas & inhibidores , Sinteninas/inmunología , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/patología , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Metabolites ; 11(4)2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33916219

RESUMEN

Metabolic reprogramming is an emerging hallmark of cancer and is driven by abnormalities of oncogenes and tumor suppressors. Accelerated metabolism causes cancer cell aggression through the dysregulation of rate-limiting metabolic enzymes as well as by facilitating the production of intermediary metabolites. However, the mechanisms by which a shift in the metabolic landscape reshapes the intracellular signaling to promote the survival of cancer cells remain to be clarified. Recent high-resolution mass spectrometry-based proteomic analyses have spotlighted that, unexpectedly, lysine residues of numerous cytosolic as well as nuclear proteins are acetylated and that this modification modulates protein activity, sublocalization and stability, with profound impact on cellular function. More importantly, cancer cells exploit acetylation as a post-translational protein for microenvironmental adaptation, nominating it as a means for dynamic modulation of the phenotypes of cancer cells at the interface between genetics and environments. The objectives of this review were to describe the functional implications of protein lysine acetylation in cancer biology by examining recent evidence that implicates oncogenic signaling as a strong driver of protein acetylation, which might be exploitable for novel therapeutic strategies against cancer.

9.
Cancers (Basel) ; 13(3)2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33503971

RESUMEN

Chemotherapy remains a primary treatment for metastatic cancer, with tumor response being the benchmark outcome marker. However, therapeutic response in cancer is unpredictable due to heterogeneity in drug delivery from systemic circulation to solid tumors. In this proof-of-concept study, we evaluated chemotherapy concentration at the tumor-site and its association with therapy response by applying a mathematical model. By using pre-treatment imaging, clinical and biologic variables, and chemotherapy regimen to inform the model, we estimated tumor-site chemotherapy concentration in patients with colorectal cancer liver metastases, who received treatment prior to surgical hepatic resection with curative-intent. The differential response to therapy in resected specimens, measured with the gold-standard Tumor Regression Grade (TRG; from 1, complete response to 5, no response) was examined, relative to the model predicted systemic and tumor-site chemotherapy concentrations. We found that the average calculated plasma concentration of the cytotoxic drug was essentially equivalent across patients exhibiting different TRGs, while the estimated tumor-site chemotherapeutic concentration (eTSCC) showed a quadratic decline from TRG = 1 to TRG = 5 (p < 0.001). The eTSCC was significantly lower than the observed plasma concentration and dropped by a factor of ~5 between patients with complete response (TRG = 1) and those with no response (TRG = 5), while the plasma concentration remained stable across TRG groups. TRG variations were driven and predicted by differences in tumor perfusion and eTSCC. If confirmed in carefully planned prospective studies, these findings will form the basis of a paradigm shift in the care of patients with potentially curable colorectal cancer and liver metastases.

10.
Int J Mol Sci ; 23(1)2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-35008495

RESUMEN

Melanoma differentiation associated gene-7/interleukin-24 (MDA-7/IL-24), a secreted protein of the IL-10 family, was first identified more than two decades ago as a novel gene differentially expressed in terminally differentiating human metastatic melanoma cells. MDA-7/IL-24 functions as a potent tumor suppressor exerting a diverse array of functions including the inhibition of tumor growth, invasion, angiogenesis, and metastasis, and induction of potent "bystander" antitumor activity and synergy with conventional cancer therapeutics. MDA-7/IL-24 induces cancer-specific cell death through apoptosis or toxic autophagy, which was initially established in vitro and in preclinical animal models in vivo and later in a Phase I clinical trial in patients with advanced cancers. This review summarizes the history and our current understanding of the molecular/biological mechanisms of MDA-7/IL-24 action rendering it a potent cancer suppressor.


Asunto(s)
Interleucinas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Apoptosis/fisiología , Autofagia/fisiología , Muerte Celular/fisiología , Humanos , Melanoma/metabolismo
11.
Mol Cancer Res ; 18(8): 1142-1152, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32366675

RESUMEN

Epigenetic regulation known for DNA methylation and histone modification is critical for securing proper gene expression and chromosomal function, and its aberration induces various pathologic conditions including cancer. Trimethylation of histone H3 on lysine 27 (H3K27me3) is known to suppress various genes related to cancer cell survival and the level of H3K27me3 may have an influence on tumor progression and malignancy. However, it remains unclear how histone methylation is regulated in response to genetic mutation and microenvironmental cues to facilitate the cancer cell survival. Here, we report a novel mechanism of the specific regulation of H3K27me3 by cooperatively two mTOR complexes, mTORC1 and mTORC2 in human glioblastoma (GBM). Integrated analyses revealed that mTORC1 upregulates the protein expression of enhancer of zeste homolog 2, a main component of polycomb repressive complex 2 which is known as H3K27-specific methyltransferase. The other mTOR complex, mTORC2, regulates production of S-adenosylmethionine, an essential substrate for histone methylation. This cooperative regulation causes H3K27 hypermethylation which subsequently promotes tumor cell survival both in vitro and in vivo xenografted mouse tumor model. These results indicate that activated mTORC1 and mTORC2 complexes cooperatively contribute to tumor progression through specific epigenetic regulation, nominating them as an exploitable therapeutic target against cancer. IMPLICATIONS: A dynamic regulation of histone methylation by mTOR complexes promotes tumor growth in human GBM, but at the same time could be exploitable as a novel therapeutic target against this deadly tumor.


Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Glioblastoma/patología , Histonas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , S-Adenosilmetionina/metabolismo , Regulación hacia Arriba , Animales , Línea Celular Tumoral , Proliferación Celular , Metilación de ADN , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Ratones , Trasplante de Neoplasias
12.
Proc Natl Acad Sci U S A ; 117(22): 12324-12331, 2020 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-32409605

RESUMEN

Glioblastoma multiforme (GBM) is an aggressive cancer without currently effective therapies. Radiation and temozolomide (radio/TMZ) resistance are major contributors to cancer recurrence and failed GBM therapy. Heat shock proteins (HSPs), through regulation of extracellular matrix (ECM) remodeling and epithelial mesenchymal transition (EMT), provide mechanistic pathways contributing to the development of GBM and radio/TMZ-resistant GBM. The Friend leukemia integration 1 (Fli-1) signaling network has been implicated in oncogenesis in GBM, making it an appealing target for advancing novel therapeutics. Fli-1 is linked to oncogenic transformation with up-regulation in radio/TMZ-resistant GBM, transcriptionally regulating HSPB1. This link led us to search for targeted molecules that inhibit Fli-1. Expression screening for Fli-1 inhibitors identified lumefantrine, an antimalarial drug, as a probable Fli-1 inhibitor. Docking and isothermal calorimetry titration confirmed interaction between lumefantrine and Fli-1. Lumefantrine promoted growth suppression and apoptosis in vitro in parental and radio/TMZ-resistant GBM and inhibited tumor growth without toxicity in vivo in U87MG GBM and radio/TMZ-resistant GBM orthotopic tumor models. These data reveal that lumefantrine, an FDA-approved drug, represents a potential GBM therapeutic that functions through inhibition of the Fli-1/HSPB1/EMT/ECM remodeling protein networks.


Asunto(s)
Antimaláricos/administración & dosificación , Antineoplásicos Alquilantes/administración & dosificación , Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Lumefantrina/administración & dosificación , Temozolomida/administración & dosificación , Neoplasias Encefálicas/radioterapia , Línea Celular Tumoral , Resistencia a Antineoplásicos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/radioterapia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Transactivadores/genética , Transactivadores/metabolismo
13.
Astrobiology ; 20(6): 785-814, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32466662

RESUMEN

On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.


Asunto(s)
Exobiología , Medio Ambiente Extraterrestre , Marte , Cuevas , Simulación por Computador , Hielo , Vuelo Espacial
14.
Cancer Lett ; 478: 1-7, 2020 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-32145344

RESUMEN

Metabolic reprogramming is a central hallmark of cancer and is driven by abnormalites of oncogenes and tumor suppressors. This enables tumor cells to obtain the macromolecular precursors and energy needed for rapid tumor growth. Accelerated metabolism also translates into cancer cell aggression through epigenetic changes. The aberrant signaling cascades activated by oncogenes coordinate metabolic reprogramming with epigenetic shifts and subsequent global transcriptional changes through the dysregulation of rate-limiting metabolic enzymes as well as by facilitating the production of intermediary metabolites. As the landscape of cancer cell metabolism has been elucidated, it is now time for this knowledge to be translated into benefit for patients. Here we review the recently identified central regulatory role for mechanistic/mammalian target of rapamycin complex 2 (mTORC2), a downstream effector of many cancer-causing mutations, in reprogramming the metabolic and epigenetic landscape. This leads to tumor cell survival and cancer drug resistance.


Asunto(s)
Redes Reguladoras de Genes , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Neoplasias/metabolismo , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Glucólisis , Humanos , Mutación , Neoplasias/genética
15.
Pharmacol Res ; 155: 104695, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32061839

RESUMEN

The primary cause of cancer-related death from solid tumors is metastasis. While unraveling the mechanisms of this complicated process continues, our ability to effectively target and treat it to decrease patient morbidity and mortality remains disappointing. Early detection of metastatic lesions and approaches to treat metastases (both pharmacological and genetic) are of prime importance to obstruct this process clinically. Metastasis is complex involving both genetic and epigenetic changes in the constantly evolving tumor cell. Moreover, many discrete steps have been identified in metastatic spread, including invasion, intravasation, angiogenesis, attachment at a distant site (secondary seeding), extravasation and micrometastasis and tumor dormancy development. Here, we provide an overview of the metastatic process and highlight a unique pro-metastatic gene, melanoma differentiation associated gene-9/Syntenin (MDA-9/Syntenin) also called syndecan binding protein (SDCBP), which is a major contributor to the majority of independent metastatic events. MDA-9 expression is elevated in a wide range of carcinomas and other cancers, including melanoma, glioblastoma multiforme and neuroblastoma, suggesting that it may provide an appropriate target to intervene in metastasis. Pre-clinical studies confirm that inhibiting MDA-9 either genetically or pharmacologically profoundly suppresses metastasis. An additional benefit to blocking MDA-9 in metastatic cells is sensitization of these cells to a second therapeutic agent, which converts anti-invasion effects to tumor cytocidal effects. Continued mechanistic and therapeutic insights hold promise to advance development of truly effective therapies for metastasis in the future.


Asunto(s)
Metástasis de la Neoplasia/genética , Neoplasias/terapia , Sinteninas/genética , Animales , Humanos , Neoplasias/genética , Neoplasias/patología
16.
Cancer Gene Ther ; 27(5): 301-310, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31130731

RESUMEN

Glioblastoma persists as a uniformly deadly diagnosis for patients and effective therapeutic options are gravely needed. Recently, targeted gene therapy approaches are reemerging as attractive experimental clinical agents. Our ligand-directed hybrid virus of adeno-associated virus and phage (AAVP) is a targeted gene delivery vector that has been used in several formulations displaying targeting ligand peptides to deliver clinically applicable transgenes. Here we compared different constructs side-by-side in a tumor model, an orthotopic model of xenograft human glioblastoma cells stereotactically implanted in immunodeficient mice. We have used divergent therapeutic strategies for two AAVP constructs, both displaying a double-cyclic RGD4C motif ligand specific for alpha V integrins expressed in tumor vascular endothelium, but carrying different genes of interest for the treatment of intracranial xenografted tumors. One construct delivered tumor necrosis factor (TNF), a purely cytotoxic gene for antitumor activity (RGD4C-AAVP-TNF); in the other construct, we delivered Herpes simplex virus thymidine kinase (HSVtk) for in tandem molecular-genetic imaging and targeted therapy (RGD4C-AAVP-HSVtk) utilizing ganciclovir (GCV) for a suicide gene therapy. Both AAVP constructs demonstrated antitumor activity, with damage to the tumor-associated neovasculature and induction of cell death evident after treatment. In addition, the ability to monitor transgene expression with a radiolabeled HSVtk substrate pre and post GCV treatment demonstrated the theranostic potential of RGD4C-AAVP-HSVtk. We conclude that targeted AAVP constructs delivering either cytotoxic TNF or theranostic HSVtk followed by suicide gene therapy with GCV have comparable preclinical efficacy, at least in this standard experimental model. The results presented here provide a blueprint for future studies of targeted gene delivery against human glioblastomas and other brain tumors.


Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias Encefálicas/terapia , Sistemas de Liberación de Medicamentos/métodos , Vectores Genéticos/administración & dosificación , Glioblastoma/terapia , Animales , Bacteriófagos/genética , Neoplasias Encefálicas/irrigación sanguínea , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Línea Celular Tumoral , Dependovirus/genética , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/patología , Femenino , Ganciclovir/administración & dosificación , Técnicas de Transferencia de Gen , Genes Transgénicos Suicidas/genética , Vectores Genéticos/genética , Glioblastoma/irrigación sanguínea , Glioblastoma/diagnóstico , Glioblastoma/genética , Humanos , Ratones , Imagen Molecular/métodos , Terapia Molecular Dirigida/métodos , Simplexvirus/genética , Timidina Quinasa/genética , Factor de Necrosis Tumoral alfa/genética , Proteínas Virales/genética , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Knee Surg Sports Traumatol Arthrosc ; 28(7): 2157-2162, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31624903

RESUMEN

PURPOSE: Bone tunnel widening following anterior cruciate ligament reconstruction (ACLR) is well documented, although the aetiology and clinical significance of this phenomenon remain unclear. At mid-term follow-up, a greater prevalence of tunnel enlargement has been reported with the use of hamstring (HS) grafts. However, there are paucity of data on what happens in the longer term. The aim of this study was to assess the change in femoral and tibial tunnel dimensions 15 years after four-strand HS ACLR. METHODS: This is a retrospective review of 15 patients who underwent arthroscopic ACLR using HS autograft tendon and were followed up radiographically at 4 months, 2 years and 15 years. Suspensory fixation was used for both ends of the graft. The diameters of the bone tunnels on posteroanterior (PA) and lateral radiographs were measured using digital callipers. Repeated measures analysis of variance (ANOVA) was used to examine change in tunnel width over time. RESULTS: Radiographic tunnel width did not significantly change between 4 months and 2 years. However, a significant decrease in width was found for both the femoral and tibial tunnels between the 2- and 15-year follow-up (P < 0.01): the femoral tunnel decreased by 50% and 51% in the PA and lateral views, respectively; the tibial tunnel decreased by 77% and 91% in the PA and lateral views respectively. There was no significant correlation between femoral or tibial tunnel width and flexion and extension deficits or with side to side differences in anterior tibial laxity at 15 years. CONCLUSIONS: This radiographic follow-up study of bone tunnel widening following HS ACLR with suspensory fixation demonstrated that tunnel width did not increase beyond 4 months and in fact had decreased significantly at long-term (15 years) follow-up. There was no correlation between tunnel width changes and clinical assessment of flexion and extension deficits or with side-to-side anterior knee laxity at 15-years. LEVEL OF EVIDENCE: IV.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior/estadística & datos numéricos , Fémur/diagnóstico por imagen , Articulación de la Rodilla/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Tibia/diagnóstico por imagen , Adulto , Ligamento Cruzado Anterior , Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/efectos adversos , Reconstrucción del Ligamento Cruzado Anterior/métodos , Autoinjertos , Femenino , Fémur/cirugía , Estudios de Seguimiento , Tendones Isquiotibiales/trasplante , Humanos , Rodilla/cirugía , Articulación de la Rodilla/cirugía , Masculino , Radiografía , Estudios Retrospectivos , Tibia/cirugía , Trasplante Autólogo , Adulto Joven
18.
J Appl Microbiol ; 129(2): 162-174, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31758754

RESUMEN

Collections of micro-organisms are a crucial element of life science research infrastructure but are vulnerable to loss and damage caused by natural or man-made disasters, the untimely death or retirement of personnel, or the loss of research funding. Preservation of biological collections has risen in priority due to a new appreciation for discoveries linked to preserved specimens, emerging hurdles to international collecting and decreased funding for new collecting. While many historic collections have been lost, several have been preserved, some with dramatic rescue stories. Rescued microbes have been used for discoveries in areas of health, biotechnology and basic life science. Suggestions for long-term planning for microbial stocks are listed, as well as inducements for long-term preservation.


Asunto(s)
Preservación Biológica , Investigación Biomédica , Biotecnología , Microbiología Ambiental , Humanos , Preservación Biológica/métodos , Preservación Biológica/tendencias , Estados Unidos
20.
J Biol Chem ; 294(51): 19740-19751, 2019 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-31712311

RESUMEN

In cancer, aberrant growth factor receptor signaling reprograms cellular metabolism and global gene transcription to drive aggressive growth, but the underlying mechanisms are not well-understood. Here we show that in the highly lethal brain tumor glioblastoma (GBM), mTOR complex 2 (mTORC2), a critical core component of the growth factor signaling system, couples acetyl-CoA production with nuclear translocation of histone-modifying enzymes including pyruvate dehydrogenase and class IIa histone deacetylases to globally alter histone acetylation. Integrated analyses in orthotopic mouse models and in clinical GBM samples reveal that mTORC2 controls iron metabolisms via histone H3 acetylation of the iron-related gene promoter, promoting tumor cell survival. These results nominate mTORC2 as a critical epigenetic regulator of iron metabolism in cancer.


Asunto(s)
Neoplasias Encefálicas/metabolismo , Epigénesis Genética , Glioblastoma/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Hierro/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Transporte Activo de Núcleo Celular , Animales , Línea Celular Tumoral , Supervivencia Celular , Regulación Neoplásica de la Expresión Génica , Histonas/química , Humanos , Proteínas Inmediatas-Precoces/metabolismo , Metaboloma , Ratones , Trasplante de Neoplasias , Regiones Promotoras Genéticas , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Piruvato Deshidrogenasa (Lipoamida)/metabolismo , Transducción de Señal
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