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1.
Biochem J ; 475(21): 3471-3492, 2018 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-30322886

RESUMEN

The occurrence of chemotherapy-resistant tumors makes ovarian cancer (OC) the most lethal gynecological malignancy. While many factors may contribute to chemoresistance, the mechanisms responsible for regulating tumor vulnerability are under investigation. Our analysis of gene expression data revealed that Sab, a mitochondrial outer membrane (MOM) scaffold protein, was down-regulated in OC patients. Sab-mediated signaling induces cell death, suggesting that this apoptotic pathway is diminished in OC. We examined Sab expression in a panel of OC cell lines and found that the magnitude of Sab expression correlated to chemo-responsiveness; wherein, OC cells with low Sab levels were chemoresistant. The Sab levels were reflected by a corresponding amount of stress-induced c-Jun N-terminal kinase (JNK) on the MOM. BH3 profiling and examination of Bcl-2 and BH3-only protein concentrations revealed that cells with high Sab concentrations were primed for apoptosis, as determined by the decrease in pro-survival Bcl-2 proteins and an increase in pro-apoptotic BH3-only proteins on mitochondria. Furthermore, overexpression of Sab in chemoresistant cells enhanced apoptotic priming and restored cellular vulnerability to a combination treatment of cisplatin and paclitaxel. Contrariwise, inhibiting Sab-mediated signaling or silencing Sab expression in a chemosensitive cell line resulted in decreased apoptotic priming and increased resistance. The effects of silencing on Sab on the resistance to chemotherapeutic agents were emulated by the silencing or inhibition of JNK, which could be attributed to changes in Bcl-2 protein concentrations induced by sub-chronic JNK inhibition. We propose that Sab may be a prognostic biomarker to discern personalized treatments for OC patients.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Ováricas/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Apoptosis/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Femenino , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética
2.
Biochem Biophys Res Commun ; 463(4): 538-44, 2015 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-26032505

RESUMEN

Chemo-sensitization is used to improve the efficacy of chemotherapeutic agents against cancers, and understanding the precise molecular mechanisms of chemo-sensitization could lead to safer and more effective approaches to treat cancer. We have previously demonstrated that mitochondrial c-Jun N-terminal Kinase (JNK) signaling is a critical component of cell death. Mitochondrial JNK signaling is coordinated on the scaffold protein Sab. In this work, we developed a sub-chronic chemo-sensitization model by exposing HeLa cells to low-dose (2 µM) LY294002. We found that this treatment increased Sab expression on mitochondria, an effect not observed in acute exposures. To examine the role of Sab in chemo-sensitization, we ectopically expressed and silenced Sab in HeLa cells. We found that elevating Sab levels in HeLa cells increased the efficacy of chemotherapeutic agents, paclitaxel and cisplatin, while silencing Sab decreased the sensitivity of cells towards these agents. The effect of Sab-mediated signaling appeared to be dependent upon mitogen dependent protein kinases (MAPKs) as ablation of Sab's MAPK-binding motifs prevented chemo-sensitization. These results suggest that mitochondrial JNK signaling is an adaptable signaling pathway that can be enhanced or restored in cancer cells to improve therapeutic efficacy.


Asunto(s)
Antineoplásicos/uso terapéutico , Cromonas/farmacología , MAP Quinasa Quinasa 4/metabolismo , Mitocondrias/efectos de los fármacos , Morfolinas/farmacología , Transducción de Señal/efectos de los fármacos , Neoplasias del Cuello Uterino/tratamiento farmacológico , Antineoplásicos/farmacología , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Células HeLa , Humanos , Mitocondrias/enzimología , Mutagénesis Sitio-Dirigida , Neoplasias del Cuello Uterino/enzimología
3.
J Natl Med Assoc ; 114(3S2): S34-S42, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35595581

RESUMEN

Lupus Nephritis is a complex clinical manifestation of systemic lupus erythematosus (SLE) associated with significant morbidity and mortality. It disproportionately affects minorities, especially African Americans (AA) with higher rates of progression to end stage kidney disease. Several factors are implicated including genetic predisposition to both SLE and chronic kidney disease, social determinants of health such as income inequality, education disparities, social isolation/lack of support, health care access and affordability. Clinically, AA may have higher auto-antibody titers, including several antibodies occurring simultaneously. AA are more prone to severe disease such as Class III and IV lupus nephritis. Fortunately, clinical trials have shown a favorable benefit/response among African Americans to mycophenolate mofetil. However, newer and alternative agents such as Rituximab, Belimumab and Voclosporin are widely unaffordable, and AA remain underrepresented in these clinical trials. The current state of disparities affecting LN patients of AA ancestry is a call for better access to healthcare and social support systems, greater inclusion/representation in clinical trials, and making new and alternative regimens more affordable and cost effective.


Asunto(s)
Fallo Renal Crónico , Lupus Eritematoso Sistémico , Nefritis Lúpica , Negro o Afroamericano/genética , Predisposición Genética a la Enfermedad , Humanos , Nefritis Lúpica/complicaciones , Nefritis Lúpica/tratamiento farmacológico , Nefritis Lúpica/genética
4.
Cureus ; 13(2): e13509, 2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33786218

RESUMEN

Antibiotic use in pneumonia is a common practice globally when there is suspicion for bacterial involvement. However, there have been few instances where the treatment is the cause of pulmonary symptoms, manifesting as so-called "multifocal pneumonia." Daptomycin is one of the main antibiotics known to have several adverse effects, including drug-induced pulmonary eosinophila. We present the case of a patient with probable daptomycin-induced acute eosinophilic pneumonia. Stopping the offending agent and concomitant steroid therapy resulted in resolution of symptoms and prevention of worsening respiratory distress.

5.
J Evid Based Complementary Altern Med ; 22(2): 260-267, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27436761

RESUMEN

Glioblastoma multiforme (GBM) is one the most aggressive and lethal human neoplasms with poor prognosis and very limited positive treatment options. The antitumor effect of supercritical CO2 extract of mango ginger ( Curcuma amada Roxb) (CA) with and without irinotecan (IR) was analyzed in U-87MG human glioblastoma multiforme (GBM) cells in vitro and in nude mice xenografts. CA is highly cytotoxic to GBM cells and is synergistic with IR as indicated by the combination index values of <1 in the CompuSyn analysis. CA inhibits tumor growth rate in GBM xenografts, the inhibition rate being higher than in IR treated group. GBM xenograft mice treated with IR + CA combination showed almost complete inhibition of tumor growth rate. Gene expression analysis of xenograft tumors indicated that IR + CA treatment significantly downregulated anti-apoptotic (Bcl-2 and mutant p53), inflammation-associated (COX-2) and cell division-associated (CCNB2) genes and upregulated pro-apoptotic genes (p21 and caspase-3). These results confirmed the therapeutic efficiency of IR + CA combination against GBM and the need for further clinical investigations.

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