RESUMEN
In this study we have identified POLθ-S6K-p62 as a novel druggable regulator of radiation response in prostate cancer. Despite significant advances in delivery, radiotherapy continues to negatively affect treatment outcomes and quality of life due to resistance and late toxic effects to the surrounding normal tissues such as bladder and rectum. It is essential to develop new and effective strategies to achieve better control of tumor. We found that ribosomal protein S6K (RPS6KB1) is elevated in human prostate tumors, and contributes to resistance to radiation. As a downstream effector of mTOR signaling, S6K is known to be involved in growth regulation. However, the impact of S6K signaling on radiation response has not been fully explored. Here we show that loss of S6K led to formation of smaller tumors with less metastatic ability in mice. Mechanistically we found that S6K depletion reduced NFκB and SQSTM1 (p62) reporter activity and DNA polymerase θ (POLθ) that is involved in alternate end-joining repair. We further show that the natural compound berberine interacts with S6K in a in a hitherto unreported novel mode and that pharmacological inhibition of S6K with berberine reduces Polθ and downregulates p62 transcriptional activity via NFκB. Loss of S6K or pre-treatment with berberine improved response to radiation in prostate cancer cells and prevented radiation-mediated resurgence of PSA in animals implanted with prostate cancer cells. Notably, silencing POLQ in S6K overexpressing cells enhanced response to radiation suggesting S6K sensitizes prostate cancer cells to radiation via POLQ. Additionally, inhibition of autophagy with CQ potentiated growth inhibition induced by berberine plus radiation. These observations suggest that pharmacological inhibition of S6K with berberine not only downregulates NFκB/p62 signaling to disrupt autophagic flux but also decreases Polθ. Therefore, combination treatment with radiation and berberine inhibits autophagy and alternate end-joining DNA repair, two processes associated with radioresistance leading to increased radiation sensitivity.
Asunto(s)
FN-kappa B , Neoplasias de la Próstata , Tolerancia a Radiación , Proteína Sequestosoma-1 , Transducción de Señal , Masculino , Animales , Humanos , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/tratamiento farmacológico , Proteína Sequestosoma-1/metabolismo , Proteína Sequestosoma-1/genética , FN-kappa B/metabolismo , FN-kappa B/genética , Transducción de Señal/efectos de los fármacos , Ratones , Tolerancia a Radiación/efectos de los fármacos , Línea Celular Tumoral , ADN Polimerasa Dirigida por ADN/genética , ADN Polimerasa Dirigida por ADN/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/genéticaRESUMEN
While macrophage phagocytosis is an immune defense mechanism against invading cellular organisms, cancer cells expressing the CD47 ligand send forward signals to repel this engulfment. Here we report that the reverse signaling using CD47 as a receptor additionally enhances a pro-survival function of prostate cancer cells under phagocytic attack. Although low CD47-expressing cancer cells still allow phagocytosis, the reverse signaling delays the process, leading to incomplete digestion of the entrapped cells and subsequent tumor hybrid cell (THC) formation. Viable THCs acquire c-Myc from parental cancer cells to upregulate both M1- and M2-like macrophage polarization genes. Consequently, THCs imitating dual macrophage features can confound immunosurveillance, gaining survival advantage in the host. Furthermore, these cells intrinsically express low levels of androgen receptor and its targets, resembling an adenocarcinoma-immune subtype of metastatic castration-resistant prostate cancer. Therefore, phagocytosis-generated THCs may represent a potential target for treating the disease.
Asunto(s)
Antígeno CD47 , Macrófagos , Metástasis de la Neoplasia , Fagocitosis , Proteínas Proto-Oncogénicas c-myc , Escape del Tumor , Humanos , Masculino , Proteínas Portadoras , Antígeno CD47/metabolismo , Macrófagos/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/inmunología , Transducción de Señal , Escape del Tumor/genética , Escape del Tumor/inmunología , Metástasis de la Neoplasia/genética , Metástasis de la Neoplasia/inmunología , Células Tumorales CultivadasRESUMEN
Chemoresistance in pancreatic cancer cells may be caused by the expansion of inherently resistant cancer cells or by the adaptive plasticity of initially sensitive cancer cells. We investigated how CD44 isoforms switching contributed to gemcitabine resistance. Treating CD44 null/low single-cell clones with increasing amounts of gemcitabine caused an increase in expression of CD44 and development of gemcitabine resistant (GR) cells. Drug sensitivity, invasiveness, and EMT process was evaluated by MTT, Matrigel invasion assays, and western blots. Genetic knockdown and pharmacological inhibitors were used to examine the roles of CD44 and IGF1R in mediating gemcitabine resistance. CD44 promoter activity and its interactive EMT-related transcription factors were evaluated by luciferase reporter assay and chromatin immunoprecipitation assay. Kaplan-Meier curve was created by log-rank test to reveal the clinical relevance of CD44 and IGF1R expression in patients. We found silence of CD44 in GR cells partially restored E-cadherin expression, reduced ZEB1 expression, and increased drug sensitivity. The gemcitabine-induced CD44 expressing and isoform switching were associated with an increase in nuclear accumulation of phosphor-cJun, Ets1, and Egr1 and binding of these transcription factors to the CD44 promoter. Gemcitabine treatment induced phosphorylation of IGF1R and increased the expression of phosphor-cJun, Ets1, and Egr1 within 72 h. Stimulation or suppression of IGF1R signaling or its downstream target promoted or blocked CD44 promoter activity. Clinically, patients whose tumors expressed high levels of CD44/IGF1R showed a poor prognosis. This study suggests that IGF1R-dependent CD44 isoform switching confers pancreatic cancer cells to undergo an adaptive change in response to gemcitabine and provides the basis for improved targeted therapy of pancreatic cancer.
Asunto(s)
Antimetabolitos Antineoplásicos , Neoplasias Pancreáticas , Antimetabolitos Antineoplásicos/farmacología , Línea Celular Tumoral , Desoxicitidina/análogos & derivados , Resistencia a Antineoplásicos/genética , Humanos , Receptores de Hialuranos/genética , Receptores de Hialuranos/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Factores de Transcripción/metabolismo , Regulación hacia Arriba , Gemcitabina , Neoplasias PancreáticasRESUMEN
Emerging evidence suggests an important role for SIRT1, a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase in cancer development, progression and therapeutic resistance; making it a viable therapeutic target. Here, we examined the impact of resveratrol-mediated pharmacological activation of SIRT1 on the progression of HGPIN lesions (using the Pten-/- mouse model) and on prostate tumor development (using an orthotopic model of prostate cancer cells stably silenced for SIRT1). We show that precise SIRT1 modulation could benefit both cancer prevention and treatment. Positive effect of SIRT1 activation can prevent Pten deletion-driven development of HGPIN lesions in mice if resveratrol is administered early (pre-cancer stage) with little to no benefit after the establishment of HGPIN lesions or tumor cell implantation. Mechanistically, our results show that under androgen deprivation conditions, SIRT1 inhibition induces senescence as evidenced by decreased gene signature associated with negative regulators of senescence and increased senescence-associated ß-galactosidase activity. Furthermore, pharmacological inhibition of SIRT1 potentiated growth inhibitory effects of clinical androgen receptor blockade agents and radiation. Taken together, our findings provide an explanation for the discrepancy regarding the role of SIRT1 in prostate tumorigenesis. Our results reveal that the bifurcated roles for SIRT1 may occur in stage and context-dependent fashion by functioning in an antitumor role in prevention of early-stage prostate lesion development while promoting tumor development and disease progression post-lesion development. Clinically, these data highlight the importance of precise SIRT1 modulation to provide benefits for cancer prevention and treatment including sensitization to conventional therapeutic approaches.
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Neoplasia Intraepitelial Prostática , Neoplasias de la Próstata , Antagonistas de Andrógenos/farmacología , Animales , Senescencia Celular , Humanos , Masculino , Ratones , Próstata/patología , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/prevención & control , Resveratrol/farmacología , Sirtuina 1/genéticaRESUMEN
BACKGROUND: Diagnosis and treatment of prostate cancer is associated with anxiety, fear, and depression in up to one-third of men. Yoga improves health-related quality of life (QoL) in patients with several types of cancer, but evidence of its efficacy in enhancing QoL is lacking in prostate cancer. METHODS: In this randomized controlled study, 29 men newly diagnosed with localized prostate cancer were randomized to yoga for 6 weeks (n = 14) or standard-of-care (n = 15) before radical prostatectomy. The primary outcome was self-reported QoL, assessed by the Expanded Prostate Index Composite (EPIC), Functional Assessment of Cancer Therapy-Prostate (FACT-P), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Functional Assessment of Cancer Therapy-General (FACT-G) at baseline, preoperatively, and 6 weeks postoperatively. Secondary outcomes were changes in immune cell status and cytokine levels with yoga. RESULTS: The greatest benefit of yoga on QoL was seen in EPIC-sexual (mean difference, 8.5 points), FACIT-F (6.3 points), FACT-Functional wellbeing (8.6 points), FACT-physical wellbeing (5.5 points), and FACT-Social wellbeing (14.6 points). The yoga group showed increased numbers of circulating CD4+ and CD8+ T-cells, more production of interferon-gamma by natural killer cells, and increased Fc receptor III expression in natural killer cells. The yoga group also showed decreased numbers of regulatory T-cells, myeloid-derived suppressor cells, indicating antitumor activity, and reduction in inflammatory cytokine levels (granulocyte colony-stimulating factor [0.55 (0.05-1.05), p = 0.03], monocyte chemoattractant protein [0.22 (0.01-0.43), p = 0.04], and FMS-like tyrosine kinase-3 ligand [0.91 (-0.01, 1.82), p = 0.053]. CONCLUSIONS: Perioperative yoga exercise improved QoL, promoted an immune response, and attenuated inflammation in men with prostate cancer. Yoga is feasible in this setting and has benefits that require further investigation. TRIAL REGISTRATION: clinicaltrials.org (NCT02620033).
Asunto(s)
Neoplasias de la Próstata , Yoga , Citocinas , Humanos , Masculino , Proyectos Piloto , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/terapia , Calidad de VidaRESUMEN
2-Methoxyestradiol (2-ME2) possesses anti-tumorigenic activities in multiple tumor models with acceptable tolerability profile in humans. Incomplete understanding of the mechanism has hindered its development as an anti-tumorigenic compound. We have identified for the first-time macrophage stimulatory protein 1 receptor (MST1R) as a potential target of 2-ME2 in prostate cancer cells. Human tissue validation studies show that MST1R (a.k.a RON) protein levels are significantly elevated in prostate cancer tissues compared to adjacent normal/benign glands. Serum levels of macrophage stimulatory protein (MSP), a ligand for RON, is not only associated with the risk of disease recurrence, but also significantly elevated in samples from African American patients. 2-ME2 treatment inhibited mechanical properties such as adhesion and elasticity that are associated with epithelial mesenchymal transition by downregulating mRNA expression and protein levels of MST1R in prostate cancer cell lines. Intervention with 2-ME2 significantly reduced tumor burden in mice. Notably, global metabolomic profiling studies identified significantly higher circulating levels of bile acids in castrated animals that were decreased with 2-ME2 intervention. In summary, findings presented in this manuscript identified MSP as a potential marker for predicting biochemical recurrence and suggest repurposing 2-ME2 to target RON signaling may be a potential therapeutic modality for prostate cancer.
Asunto(s)
2-Metoxiestradiol/farmacología , Reposicionamiento de Medicamentos , Proteínas de Neoplasias , Neoplasias de la Próstata , Proteínas Tirosina Quinasas Receptoras , Animales , Humanos , Masculino , Ratones , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismo , Células PC-3 , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/enzimología , Neoplasias de la Próstata/patología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/metabolismoRESUMEN
NAD[P]H:quinone oxidoreductase 1 (NQO1) regulates cell fate decisions in response to stress. Oxidative stress supports cancer maintenance and progression. Previously we showed that knockdown of NQO1 (NQO1low) prostate cancer cells upregulate pro-inflammatory cytokines and survival under hormone-deprived conditions. Here, we tested the ability of NQO1low cells to form tumors. We found NQO1low cells form aggressive tumors compared with NQO1high cells. Biopsy specimens and circulating tumor cells showed biochemical recurrent prostate cancer was associated with low NQO1. NQO1 silencing was sufficient to induce SMAD-mediated TGFß signaling and mesenchymal markers. TGFß treatment decreased NQO1 levels and induced molecular changes similar to NQO1 knockdown cells. Functionally, NQO1 depletion increased migration and sensitivity to oxidative stress. Collectively, this work reveals a possible new gatekeeper role for NQO1 in counteracting cellular plasticity in prostate cancer cells. Further, combining NQO1 with TGFß signaling molecules may serve as a better signature to predict biochemical recurrence.
Asunto(s)
Plasticidad de la Célula/genética , NAD(P)H Deshidrogenasa (Quinona)/genética , Estrés Oxidativo , Neoplasias de la Próstata/fisiopatología , Factor de Crecimiento Transformador beta/genética , Animales , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Ratones , Ratones Desnudos , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Neoplasias de la Próstata/genética , Factor de Crecimiento Transformador beta/metabolismo , Regulación hacia Arriba/fisiologíaRESUMEN
The general transcription factor E2F1 reportedly functions in a protumorigenic manner in several cancer models. We show that the genetic context of cancer cells influence E2F1's role to impede the protumorigenic role. Thirty to fifty percent of melanoma patients carry mutant BRAF with about 90% of mutant BRAF melanomas being V600E mutation. Tissue microarrays from melanoma patients were used to establish an association between E2F1 and BRAFV600E . We show for the first time that low E2F1 levels in BRAFV600E melanomas are associated with lymph node metastasis. Genetic manipulation of E2F1 in BRAFV600E and BRAFwt cells were used to determine its role in malignant melanoma progression by examining effects on migration and invasion. E2F1-mediated negative regulation of myosin light chain kinase (MYLK) increased migration and invasion in BRAFV600E cells by phosphorylating myosin light chain and increased stress fiber formation. We show that E2F1 inhibits extracellular signal-regulated kinase (ERK) activation in BRAFV600E cells and provide evidence for a negative feedback loop between E2F1 and ERK in these cells. This study shows for the first time that E2F1 has a cancer protective role in oncogenic BRAF-activated melanoma cells and that loss of E2F1 can allow disease progression through a novel mechanism of E2F1-mediated MYLK regulation. This study has implications for oncogenic BRAF-activated tumors and resistance to targeted oncogenic BRAF therapy.
Asunto(s)
Movimiento Celular/genética , Factor de Transcripción E2F1/genética , Melanoma/genética , Melanoma/patología , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Humanos , Metástasis Linfática/genética , Metástasis Linfática/patología , Sistema de Señalización de MAP Quinasas/genética , Mutación/genética , Fosforilación/genética , Proteínas Proto-Oncogénicas B-raf/genética , Melanoma Cutáneo MalignoRESUMEN
Published evidence shows a correlation between several molecular markers and prostate cancer (PCa) progression including in African Americans (AAs) who are disproportionately affected. Our early detection efforts led to the identification of elevated levels of antiapoptotic protein, c-FLIP and its upstream regulatory factors such as androgen receptor (AR), recepteur d'origine nantais (RON), a receptor tyrosine kinase in human prostate tumors. The primary objective of this study was to explore whether these markers play a role in racial disparities using immunohistochemistry in prostatectomy samples from a cohort of AA, Hispanic Whites (HWs), and non-Hispanic Whites (NHWs). Bivariable and multivariable logistic regression analyses were used to identify a statistical association between molecular markers, possible correlation with risk factors including race, obesity, prostate-specific antigen (PSA) and disease aggressiveness. Further, changes in the levels and expression of these molecular markers were also evaluated using human PCa cell lines. We found significantly elevated levels of RON ( P = 0.0082), AR ( P = 0.0001), c-FLIP ( P = 0.0071) in AAs compared with HWs or NHWs. Furthermore, a higher proportion of HW and NHWs had a high Gleason score (>6) but not PSA as compared to AAs ( P = 0.032). In summary, our findings suggest that PSA was important in predicting aggressive disease for the cohort overall; however, high levels of RON may play a role in predisposing AA men to develop aggressive disease. Future research is needed using large datasets to confirm these findings and to explore whether all or any of these markers could aid in race-specific stratification of patients for treatment.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Próstata/etnología , Neoplasias de la Próstata/cirugía , Proteínas Tirosina Quinasas Receptoras/metabolismo , Regulación hacia Arriba , Adulto , Negro o Afroamericano , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/metabolismo , Línea Celular Tumoral , Estudios de Cohortes , Regulación Neoplásica de la Expresión Génica , Hispánicos o Latinos , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Prostatectomía , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Proteínas Tirosina Quinasas Receptoras/genética , Receptores Androgénicos/metabolismo , Población BlancaRESUMEN
COBRA1 (co-factor of BRCA1) is one of the four subunits of the negative elongation factor originally identified as a BRCA1-interacting protein. Here, we provide first-time evidence for the oncogenic role of COBRA1 in prostate pathogenesis. COBRA1 is aberrantly expressed in prostate tumors. It positively influences androgen receptor (AR) target gene expression and promoter activity. Depletion of COBRA1 leads to decreased cell viability, proliferation, and anchorage-independent growth in prostate cancer cell lines. Conversely, overexpression of COBRA1 significantly increases cell viability, proliferation, and anchorage-independent growth over the higher basal levels. Remarkably, AR-positive androgen dependent (LNCaP) cells overexpressing COBRA1 survive under androgen-deprivation conditions. Remarkably, treatment of prostate cancer cells with well-studied antitumorigenic agent, 2-methoxyestradiol (2-ME2), caused significant DNA methylation changes in 3255 genes including COBRA1. Furthermore, treatment of prostate cancer cells with 2-ME2 downregulates COBRA1 and inhibition of prostate tumors in TRAMP (transgenic adenocarcinomas of mouse prostate) animals with 2-ME2 was also associated with decreased COBRA1 levels. These observations implicate a novel role for COBRA1 in progression to CRPC and suggest that COBRA1 downregulation has therapeutic potential.
Asunto(s)
Proteína BRCA1/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias de la Próstata/metabolismo , Factores de Transcripción/metabolismo , 2-Metoxiestradiol , Animales , Proteína BRCA1/genética , Proliferación Celular/genética , Proliferación Celular/fisiología , Supervivencia Celular/genética , Supervivencia Celular/fisiología , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Estradiol/análogos & derivados , Estradiol/farmacología , Regulación Neoplásica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Masculino , Ratones , Proteínas Nucleares/genética , Neoplasias de la Próstata/genética , Unión Proteica , Proteínas de Unión al ARN , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Factores de Transcripción/genéticaRESUMEN
Radiation therapy (XRT) is a standard treatment for prostate cancer (PCa). Although dose escalation increases local control, toxicity hampers further escalation. Broader improvement will be possible by the addition of adjuvant therapies, which can synergize with radiation and thus improve efficacy. We have identified a natural compound (Nexrutine, Nx) that inhibits the survival and growth of PCa cells in combination with radiation. Combination studies demonstrated strong interaction between Nx and radiation both in vitro in multiple PCa cell lines and in the Transgenic adenocarcinoma of mouse prostate (TRAMP) model. Nx potentiated growth inhibitory effects of IR by down regulating ribosomal protein S6K (RPS6KB1), CyclinD1, Chk1 and HIF-1 α and prolonging G2/M checkpoint block. RPS6KB1 is upregulated in prostate cancers and its expression is correlated with tumor grade. Knockdown of RPS6KB1 in PCa cells increased their sensitivity toward radiation-induced survival inhibition. Overall, we provide scientific evidence (i) in support of Nx as an adjuvant in PCa patients receiving XRT (ii) suggesting that RPS6KB1 is an important player in Nx-mediated combinatorial benefits and emphasizes that RPS6KB1 is a novel target for PCa treatment. These data underscore the need to test the agent in additional preclinical models to validate these observations.
Asunto(s)
Antineoplásicos/farmacología , Extractos Vegetales/farmacología , Neoplasias de la Próstata/radioterapia , Proteínas Quinasas S6 Ribosómicas 70-kDa/antagonistas & inhibidores , Proteínas Quinasas S6 Ribosómicas 70-kDa/genética , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/biosíntesis , Ciclina D1/biosíntesis , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Masculino , Ratones , Células PC-3 , Proteínas Quinasas S6 Ribosómicas 70-kDa/biosíntesisRESUMEN
Reciprocal interaction between pancreatic stellate cells (PSCs) and cancer cells (PCCs) in the tumor microenvironment (TME) promotes tumor cell survival and progression to lethal, therapeutically resistant pancreatic cancer. The goal of this study was to test the ability of Palmatine (PMT) to disrupt this reciprocal interaction in vitro and examine the underlying mechanism of interaction. We show that PSCs secrete glutamine into the extracellular environment under nutrient deprivation. PMT suppresses glutamine-mediated changes in GLI signaling in PCCs resulting in the inhibition of growth and migration while inducing apoptosis by inhibition of survivin. PMT-mediated inhibition of (glioma-associated oncogene 1) GLI activity in stellate cells leads to suppression (collagen type 1 alpha 1) COL1A1 activation. Remarkably, PMT potentiated gemcitabine's growth inhibitory activity in PSCs, PCCs and inherently gemcitabine-resistant pancreatic cancer cells. This is the first study that shows the ability of PMT to inhibit growth of PSCs and PCCs either alone or in combination with gemcitabine. These studies warrant additional investigations using preclinical models to develop PMT as an agent for clinical management of pancreatic cancer.
Asunto(s)
Alcaloides de Berberina/farmacología , Comunicación Celular/efectos de los fármacos , Colágeno Tipo I/antagonistas & inhibidores , Glutamina/metabolismo , Células Estrelladas Pancreáticas/metabolismo , Survivin/antagonistas & inhibidores , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Cadena alfa 1 del Colágeno Tipo I , Humanos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Células Estrelladas Pancreáticas/citología , Transducción de Señal/efectos de los fármacos , Survivin/genética , Survivin/metabolismo , Microambiente Tumoral/efectos de los fármacosRESUMEN
Increasing evidence suggests the presence of minor cell subpopulations in prostate cancer that are androgen independent and poised for selection as dominant clones after androgen deprivation therapy. In this study, we investigated this phenomenon by stratifying cell subpopulations based on transcriptome profiling of 144 single LNCaP prostate cancer cells treated or untreated with androgen after cell-cycle synchronization. Model-based clustering of 397 differentially expressed genes identified eight potential subpopulations of LNCaP cells, revealing a previously unappreciable level of cellular heterogeneity to androgen stimulation. One subpopulation displayed stem-like features with a slower cell doubling rate, increased sphere formation capability, and resistance to G2-M arrest induced by a mitosis inhibitor. Advanced growth of this subpopulation was associated with enhanced expression of 10 cell-cycle-related genes (CCNB2, DLGAP5, CENPF, CENPE, MKI67, PTTG1, CDC20, PLK1, HMMR, and CCNB1) and decreased dependence upon androgen receptor signaling. In silico analysis of RNA-seq data from The Cancer Genome Atlas further demonstrated that concordant upregulation of these genes was linked to recurrent prostate cancers. Analysis of receiver operating characteristic curves implicates aberrant expression of these genes and could be useful for early identification of tumors that subsequently develop biochemical recurrence. Moreover, this single-cell approach provides a better understanding of how prostate cancer cells respond heterogeneously to androgen deprivation therapies and reveals characteristics of subpopulations resistant to this treatment.Significance: Illustrating the challenge in treating cancers with targeted drugs, which by selecting for drug resistance can drive metastatic progression, this study characterized the plasticity and heterogeneity of prostate cancer cells with regard to androgen dependence, defining the character or minor subpopulations of androgen-independent cells that are poised for clonal selection after androgen-deprivation therapy. Cancer Res; 78(4); 853-64. ©2017 AACR.
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Andrógenos/metabolismo , Perfilación de la Expresión Génica/métodos , Neoplasias de la Próstata/genética , ARN/metabolismo , Línea Celular Tumoral , Humanos , Masculino , Neoplasias de la Próstata/patologíaRESUMEN
Lack of effective options following failure to conventional chemotherapeutic agent such as Docetaxel (DX) is a major clinical challenge in the management of prostate cancer. These observations underscore the need for deciphering the underlying mechanism of DX resistance to enable the development of effective therapeutic approaches. We observed up regulation of the anti-apoptotic protein c-FLIP and its up stream regulators including receptor tyrosine kinase RON and transcription factor NFκB (p65) in tumors obtained from metastatic prostate cancer patients. We also observed significant downregulation of these molecules in prostate tumors isolated from patients treated with DX as first line therapy. Further, we identified the over the counter anti-inflammatory agent, Nexrutine (NX) suppresses c-FLIP protein levels, and expression in androgen-independent prostate cancer cells (PC-3). Remarkably, the observed decreased levels of c-FLIP were further reduced in combination with DX. Transient expression assays coupled with electrophoretic mobility shift and DNA affinity protein assay revealed that NX and DX suppresses c-FLIP promoter activity by preventing p65 binding. Notably, NX in combination with DX abolished binding of p65 to the c-FLIP promoter sequence containing NFκB binding sites. Biologically, these alterations resulted in reduced growth of PC-3 cells. Taken together, these observations suggest the utility of RON, p65, and c-FLIP as potential markers to predict response to DX treatment. Furthermore, our results also identified NX as an agent to potentiate the therapeutic response of DX by suppressing activation of c-FLIP and its upstream regulators.
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Antineoplásicos/administración & dosificación , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/genética , FN-kappa B/genética , Extractos Vegetales/administración & dosificación , Neoplasias de la Próstata/tratamiento farmacológico , Taxoides/administración & dosificación , Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Docetaxel , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Metástasis de la Neoplasia , Extractos Vegetales/farmacología , Neoplasias de la Próstata/genética , Transducción de Señal/efectos de los fármacos , Taxoides/farmacologíaRESUMEN
There is an unmet need to develop new agents or strategies against therapy resistant pancreatic cancer (PanCA). Recent studies from our laboratory showed that STAT3 negatively regulates NF-κB and that inhibition of this crosstalk using Nexrutine® (Nx) reduces transcriptional activity of COX-2. Inhibition of these molecular interactions impedes pancreatic cancer cell growth as well as reduces fibrosis in a preclinical animal model. Nx is an extract derived from the bark of Phellodendron amurense and has been utilized in traditional Chinese medicine as antidiarrheal, astringent, and anti-inflammatory agent for centuries. We hypothesized that "Nx-mediated inhibition of survival molecules like STAT3 and NF-κB in pancreatic cancer cells will improve the efficacy of the conventional chemotherapeutic agent, gemcitabine (GEM)." Therefore, we explored the utility of Nx, one of its active constituents berberine and its derivatives, to enhance the effects of GEM. Using multiple human pancreatic cancer cells we found that combination treatment with Nx and GEM resulted in significant alterations of proteins in the STAT3/NF-κB signaling axis culminating in growth inhibition in a synergistic manner. Furthermore, GEM resistant cells were more sensitive to Nx treatment than their parental GEM-sensitive cells. Interestingly, although berberine, the Nx active component used, and its derivatives were biologically active in GEM sensitive cells they did not potentiate GEM activity when used in combination. Taken together, these results suggest that the natural extract, Nx, but not its active component, berberine, has the potential to improve GEM sensitivity, perhaps by down regulating STAT3/NF-κB signaling. © 2016 Wiley Periodicals, Inc.
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Antiinflamatorios/farmacología , Antimetabolitos Antineoplásicos/farmacología , Desoxicitidina/análogos & derivados , Resistencia a Antineoplásicos/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Neoplasias Pancreáticas/tratamiento farmacológico , Extractos Vegetales/farmacología , Factor de Transcripción STAT3/antagonistas & inhibidores , Antiinflamatorios/química , Berberina/química , Berberina/farmacología , Línea Celular Tumoral , Desoxicitidina/farmacología , Regulación hacia Abajo/efectos de los fármacos , Humanos , FN-kappa B/inmunología , Páncreas/efectos de los fármacos , Páncreas/inmunología , Neoplasias Pancreáticas/inmunología , Phellodendron/química , Extractos Vegetales/química , Factor de Transcripción STAT3/inmunología , Transducción de Señal/efectos de los fármacos , GemcitabinaRESUMEN
PURPOSE OF THE REVIEW: The 5-year survival rate of patients with pancreatic cancer (PanCA) has remained stagnant. Unfortunately, the incidence is almost equal to mortality rates. These facts underscore the importance of concerted efforts to understand the pathology of this disease. Deregulation of multiple signaling pathways involved in a wide variety of cellular processes including proliferation, apoptosis, invasion, and metastasis contribute not only to cancer development but also to therapeutic resistance. The purpose of this review is to summarize current understanding of etiological factors including emerging evidence on the role of infectious agents, factors associated with therapeutic resistance and therapeutic options. RECENT FINDINGS: The unique aspect of PanCA is "desmoplasia", a process that involves proliferation of stromal fibroblasts and collagen deposition in and around the filtrating cancer. Recent studies have identified pancreatic stellate cells (PSCs) as a potential source of such desmoplasia. Biphasic interactions between PSCs and cancer cells, endothelial cells, and/or myeloid derived suppressor cells in the tumor microenvironment contribute to pancreatic carcinogenesis. SUMMARY: We summarize limitations of current therapeutic approaches and potential strategies to overcome these limitations using natural products including botanicals as adjuvant/neo-adjuvant for effective management of PanCA.
RESUMEN
The rise in cancer incidence and mortality in developing countries together with the human and financial cost of current cancer therapy mandates a closer look at alternative ways to overcome this burgeoning global healthcare problem. Epidemiological evidence for the association between cancer and diet and the long latency of most cancer progression have led to active exploration of whole and isolated natural chemicals from different naturally occurring substances in various preclinical and clinical settings. In general the lack of systemic toxicities of most 'whole' and 'isolated' natural compounds, their potential to reduce toxic doses and potential to delay the development of drug-resistance makes them promising candidates for cancer management. This review article examines the suggested molecular mechanisms affected by these substances focusing to a large extent on prostate cancer and deliberates on the disparate results obtained from cell culture, preclinical and clinical studies in an effort to highlight the use of whole extracts and isolated constituents for intervention. As such these studies underscore the importance of factors such as treatment duration, bioavailability, route of administration, selection criteria, standardized formulation and clinical end points in clinical trial design with both entities. Overall lack of parallel comparison studies between the whole natural products and their isolated compounds limits decisive conclusions regarding the superior utility of one over the other. We suggest the critical need for rigorous comparative research to identify which one of the two or both entities from nature would be best qualified to take on the mantle of cancer management.
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Antineoplásicos Fitogénicos/farmacología , Neoplasias/tratamiento farmacológico , Extractos Vegetales/farmacología , Animales , Antineoplásicos Fitogénicos/uso terapéutico , Dieta , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Neoplasias/metabolismo , Extractos Vegetales/uso terapéutico , Transducción de Señal/efectos de los fármacosRESUMEN
PURPOSE: A subpopulation of pancreatic ductal adenocarcinoma (PDAC) cells is thought to be inherently resistant to chemotherapy or to give rise to tumor cells that become resistant during treatment. Here we determined the role of CD44 expression and its isoforms as a marker and potential target for tumor cells that give rise to invasive and gemcitabine-resistant tumors. EXPERIMENTAL DESIGN: RT-PCR, Western blotting, and DNA sequencing was used to determine CD44 isoform and expression levels. Flow cytometry was used to sort cells on the basis of their CD44 expression level. CD44 expression was knocked down using shRNA. Tumorigenic properties were determined by clonogenic and Matrigel assays, IHC, tumor growth in vivo using luciferase imaging and by tumor weight. RESULTS: We identified an invasive cell population that gives rise to gemcitabine-resistant tumors. These cancer cells express a high level of CD44 standard isoform and have an EMT phenotype (CD44s/EMT). In vivo, CD44s/EMT engraft and expand rapidly and give rise to tumors that express high levels of CD44 isoforms that contain multiple exon variants. CD44low-expressing cells show continued sensitivity to gemcitabine in vivo and knockdown of CD44 in CD44s/EMT cells increases sensitivity to gemcitabine and decreases invasiveness. CONCLUSIONS: PDAC cells expressing high levels of CD44s with a mesenchymal-like phenotype were highly invasive and developed gemcitabine resistance in vivo Thus, initial targeting CD44 or reversing the CD44high phenotype may improve therapeutic response. Clin Cancer Res; 22(22); 5592-604. ©2016 AACR.
Asunto(s)
Carcinoma Ductal Pancreático/patología , Movimiento Celular/fisiología , Receptores de Hialuranos/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Isoformas de Proteínas/metabolismo , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Neoplasias Pancreáticas/tratamiento farmacológico , ARN Interferente Pequeño/metabolismo , Gemcitabina , Neoplasias PancreáticasRESUMEN
The current standard of care for prostate cancer includes hormone therapy, radiation therapy and radical prostatectomy, each with its own set of undesirable side effects. In this regard there is an unmet need to develop strategies that can prevent or delay the development of clinical prostate cancer. One potential area involves the use of natural compounds involving botanicals. Along these lines we have found that Nexrutine®, a dietary supplement derived from Phellodendron amurense bark extract, has prostate cancer prevention activity. The "extract" nature of this botanical, which constitutes a blend of several active protoberberine alkaloids, allows it to target several pathways deregulated in prostate cancer simultaneously. In this review, we will emphasize the prospective translational benefit of Nexrutine® as a chemopreventive agent for prostate cancer management. The potential of Nexrutine® was first identified and has subsequently been most exhaustively studied with reference to prostate cancer. Therefore the focus of this review is on the use of Nexrutine® in prostate cancer. In addition we have summarized the emerging evidence regarding the use of Nexrutine® in other tumor models to demonstrate the potential benefits of Nexrutine®.