RESUMO
Platinum based drugs alone or in combination with 5FU and docetaxel are common regimen chemotherapeutics for the treatment of advanced OSCC. Chemoresistance is one of the major factors of treatment failure in OSCC. Human RNA helicase DDX3 plays an important role in cell proliferation, invasion, and metastasis in several neoplasms. The potential role of DDX3 in chemoresistance is yet to be explored. Enhanced cancer stem cells (CSCs) population significantly contributes to chemoresistance and recurrence. A recent study showed that m6A RNA regulates self-renewal and tumorigenesis property in cancer. In this study we found genetic (shRNA) or pharmacological (ketorolac salt) inhibition of DDX3 reduced CSC population by suppressing the expression of FOXM1 and NANOG. We also found that m6A demethylase ALKBH5 is directly regulated by DDX3 which leads to decreased m6A methylation in FOXM1 and NANOG nascent transcript that contribute to chemoresistance. Here, we found DDX3 expression was upregulated in both cisplatin-resistant OSCC lines and chemoresistant tumors when compared with their respective sensitive counterparts. In a patient-derived cell xenograft model of chemoresistant OSCC, ketorolac salt restores cisplatin-mediated cell death and facilitates a significant reduction of tumor burdens. Our work uncovers a critical function of DDX3 and provides a new role in m6 demethylation of RNA. A combination regimen of ketorolac salt with cisplatin deserves further clinical investigation in advanced OSCC.
Assuntos
Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Cisplatino/farmacologia , RNA Helicases DEAD-box/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias Bucais/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , RNA Helicases DEAD-box/antagonistas & inibidores , RNA Helicases DEAD-box/genética , Desmetilação , Proteína Forkhead Box M1/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Cetorolaco de Trometamina/farmacologia , Cetorolaco de Trometamina/uso terapêutico , Camundongos , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/metabolismo , Proteína Homeobox Nanog/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , RNA Mensageiro/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Cisplatin alone or in combination with 5FU (5-fluorouracil) and docetaxel (TPF) are common regimen chemotherapeutics for treatment of advanced oral squamous cell carcinoma (OSCC). Despite the initial positive response, several patients experience relapse due to chemoresistance. The potential role of Bcl-2 antiapoptotic members in acquired chemoresistance is yet to be explored. To address this, we designed two different relevant OSCC chemoresistant models: (i) acquired chemoresistant cells, where OSCC lines were treated with conventional chemotherapy for a prolonged period to develop chemoresistance, and (ii) chemoresistant patient-derived cells, where primary cells were established from tumor of neoadjuvant-treated OSCC patients who do not respond to TPF. Among all Bcl-2 antiapoptotic members, Mcl-1 expression (but not Bcl-2 or Bcl-xL) was found to be upregulated in both chemoresistant OSCC lines and chemoresistant tumors when compared with their respective sensitive counterparts. Irrespective of all three chemotherapy drugs, Mcl-1 expression was elevated in OSCC cells that are resistant to either cisplatin or 5FU or docetaxel. In chemoresistant OSCC, Mcl-1 mRNA was upregulated by signal transducer and activator of transcription 3 (STAT3) activation, and the protein was stabilized by AKT-mediated glycogen synthase kinase 3 beta (GSK3ß) inactivation. Genetic (siRNA) or pharmacological (Triptolide, a transcriptional repressor of Mcl-1) inhibition of Mcl-1 induces drug-mediated cell death in chemoresistant OSCC. In patient-derived xenograft model of advanced stage and chemoresistant OSCC tumor, Triptolide restores cisplatin-mediated cell death and facilitates significant reduction of tumor burdens. Overall, our data suggest Mcl-1 dependency of chemoresistant OSCC. A combination regimen of Mcl-1 inhibitor with conventional chemotherapy deserves further clinical investigation in advanced OSCC.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Glicogênio Sintase Quinase 3 beta/fisiologia , Neoplasias Bucais/tratamento farmacológico , Proteína de Sequência 1 de Leucemia de Células Mieloides/fisiologia , Fator de Transcrição STAT3/fisiologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Diterpenos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Compostos de Epóxi/farmacologia , Fluoruracila/uso terapêutico , Humanos , Masculino , Camundongos , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Fenantrenos/farmacologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Taxoides/uso terapêuticoRESUMO
Textile wet processing highly impacts the environment due to its massive water and energy consumption. High consumption of water also results in the generation of a considerable volume of effluents. In this regard, an ultraviolet C (UVC)-assisted desizing method of starch-sized cotton fabric has been developed to lower the utility consumption in textile pretreatment. A UVC cabinet is designed to control exposing temperature and energy of exposure on the starch-sized cotton fabric. The UVC exposure time is optimized concerning the desizing efficiency. The UVC-exposed-sized fabric is washed with different washing times and washing temperatures to optimize the process. The alkali consumption in washing is reduced by 75% and desizing efficiency is improved to 95%. The application of oxidizing agents like NaNO2, K2S2O8, and NaBO3·4H2O during sizing further reduced the washing temperature and washing time for desizing to obtain 100% desizing efficiency. The UVC-assisted desized fabric is characterized by the whiteness index, water absorbency, tensile strength, Fourier transform infrared (FTIR), and wide-angle X-ray diffraction and compared with the control. The UVC-assisted desizing process has the potential to save approximately 60% water, 90% energy, and more than 70% of the time. Life cycle analysis has also been done. The photocatalytic desizing process can reduce the impact on human health by more than 85% and save approximately 69% of mineral resources than the conventional technique. The textile industry can quickly adopt a novel approach for sustainable desizing.
Assuntos
Criptococose/microbiologia , Dermatomicoses/microbiologia , Transplante de Rim/efeitos adversos , Pele/microbiologia , Transplantados , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Biópsia , Criança , Criptococose/diagnóstico , Criptococose/tratamento farmacológico , Dermatomicoses/diagnóstico , Dermatomicoses/tratamento farmacológico , Quimioterapia Combinada , Fluconazol/uso terapêutico , Humanos , Masculino , Pele/efeitos dos fármacos , Pele/patologia , Fatores de Tempo , Resultado do TratamentoRESUMO
Cancer is a daunting global problem confronting the world's population. The most frequent therapeutic approaches include surgery, chemotherapy, radiotherapy, and more recently immunotherapy. In the case of chemotherapy, patients ultimately develop resistance to both single and multiple chemotherapeutic agents, which can culminate in metastatic disease which is a major cause of patient death from solid tumors. Chemoresistance, a primary cause of treatment failure, is attributed to multiple factors including decreased drug accumulation, reduced drug-target interactions, increased populations of cancer stem cells, enhanced autophagy activity, and reduced apoptosis in cancer cells. Reprogramming tumor cells to undergo drug-induced apoptosis provides a promising and powerful strategy for treating resistant and recurrent neoplastic diseases. This can be achieved by downregulating dysregulated antiapoptotic factors or activation of proapoptotic factors in tumor cells. A major target of dysregulation in cancer cells that can occur during chemoresistance involves altered expression of Bcl-2 family members. Bcl-2 antiapoptotic molecules (Bcl-2, Bcl-xL, and Mcl-1) are frequently upregulated in acquired chemoresistant cancer cells, which block drug-induced apoptosis. We presently overview the potential role of Bcl-2 antiapoptotic proteins in the development of cancer chemoresistance and overview the clinical approaches that use Bcl-2 inhibitors to restore cell death in chemoresistant and recurrent tumors.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Autofagia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Animais , Humanos , Neoplasias/metabolismo , Neoplasias/patologiaRESUMO
Development of a gene discovery tool for heterologously expressed cytochrome P450 monooxygenases has been inherently difficult. The activity assays are labor-intensive and not amenable to parallel screening. Additionally, biochemical confirmation requires coexpression of a homologous P450 reductase or complementary heterologous activity. Plant virus gene expression systems have been utilized for a diverse group of organisms. In this study we describe a method using an RNA vector expression system to phenotypically screen for cytochrome P450-dependent fatty acid omega-hydroxylase activity. Yarrowia lipolytica CYP52 gene family members involved in n-alkane assimilation were amplified from genomic DNA, cloned into a plant virus gene expression vector, and used as a model system for determining heterologous expression. Plants infected with virus vectors expressing the yeast CYP52 genes (YlALK1-YlALK7) showed a distinct necrotic lesion phenotype on inoculated plant leaves. No phenotype was detected on negative control constructs. YlALK3-, YlALK5-, and YlALK7-inoculated plants all catalyzed the terminal hydroxylation of lauric acid as confirmed using thin-layer and gas chromatography/mass spectrometry methods. The plant-based cytochrome P450 phenotypic screen was tested on an n-alkane-induced Yarrowia lipolytica plant virus expression library. A subset of 1,025 random library clones, including YlALK1-YlALK7 constructs, were tested on plants. All YlALK gene constructs scored positive in the randomized screen. Following nucleotide sequencing of the clones that scored positive using a phenotypic screen, approximately 5% were deemed appropriate for further biochemical analysis. This report illustrates the utility of a plant-based system for expression of heterologous cytochrome P450 monooxygenases and for the assignment of gene function.
Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Vetores Genéticos , Nicotiana/enzimologia , Vírus de RNA/genética , Yarrowia/enzimologia , Células Cultivadas , Cromatografia em Camada Fina , Citocromo P-450 CYP4A/biossíntese , Citocromo P-450 CYP4A/genética , Sistema Enzimático do Citocromo P-450/genética , Cromatografia Gasosa-Espectrometria de Massas , Expressão Gênica , Microssomos/enzimologia , Fenótipo , Folhas de Planta/enzimologia , Folhas de Planta/ultraestrutura , Nicotiana/ultraestrutura , Transcrição GênicaRESUMO
Microvascular reconstruction is now widely available in India. However the sitution was quite different two decades back. Methods: The procedure was available only in a very few centers located mostly in the metro cities. It was considered a very complex and difficult surgery requiring height degree of skill and precision. Spreading or establishing this technique in smaller cities was filled with lot of challenges and was never an easy task. Results: The most difficult part was to gain the confidence of local oncosurgeons who refused to believe that this technique could be executed in smaller centers and cities.This article is a study of the factors and challenges faced by the author to establish this technique in the state of Odisha. Conclusion: It took a couple of years to convince the oncosurgeons to initiate the procedure. Another five years to consolidate. Since 2010 its a well established technique in the state of Odisha. The microvascular surgeons trained under the author and from other centers outside the state have spread the proceduree to many more centers in Odisha. From an occasional procedure in 2003, Microvascular reconstruction has become a routine procedure in Odisha today.
RESUMO
AIM: The present study deals with preparation of zidovudine loaded microparticle by counter ion induced aggregation method. During this study effect of polyacrylates and hypromellose polymers on release study were investigated. MATERIALS AND METHODS: The ion induced aggregated alginate based microparticles were characterized for surface morphology, particle size analysis, drug entrapment study, in-vitro study, Fourier-transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC) study. RESULTS AND DISCUSSION: The result showed Eudragit RL-100 (ERL) based formulations had smoother surface as well as their mean particle sizes were found greater compared with Eudragit RS-100 (ERS) microparticles. Furthermore, drug entrapments were found to be more in ERL formulae as compared with ERS. RL3 released 101.05% drug over a period of 8(th) h and followed Higuchi profile and Fickian diffusion. Moreover, data obtained illustrated that, higher amount of quaternary ammonium group, alkali value, and glass transition temperature may be possible reason for improving permeability of ERL based formulations. It was also noticed, hyroxypropyl methylcellulose (HPMC) K4M premium grade polymer sustained drug release more than HPMC K15M. In addition, drug-excipient interaction study was carried out by FTIR and DSC study.
RESUMO
Cervical cystic mass is a rare presentation of papillary thyroid carcinoma. This cystic change can cause diagnostic problems and not infrequently, delay identification of the primary thyroid tumor. We present a rare case of cystic papillary thyroid carcinoma, which is presented as asymptomatic neck mass of long duration. Their clinical presentation, diagnosis and management were reviewed.