OLIVEIRA, F. F. B. Mecanismos envolvidos na síndrome da dor aguda induzida por paclitaxel em camundongos: participação de mastócitos e células satélites gliais. 2017. 166 f. Tese (Doutorado em Farmacologia) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Farmacologia Pós-Graduação (posgfarmacologia@gmail.com) on 2017-08-10T15:06:27Z No. of bitstreams: 1 2017_tese_ffboliveira.pdf: 5786745 bytes, checksum: a99e6b2e181fb5242758de5ab1334d5e (MD5) / Approved for entry into archive by Erika Fernandes (erikaleitefernandes@gmail.com) on 2017-08-10T15:36:36Z (GMT) No. of bitstreams: 1 2017_tese_ffboliveira.pdf: 5786745 bytes, checksum: a99e6b2e181fb5242758de5ab1334d5e (MD5) / Made available in DSpace on 2017-08-10T15:36:37Z (GMT). No. of bitstreams: 1 2017_tese_ffboliveira.pdf: 5786745 bytes, checksum: a99e6b2e181fb5242758de5ab1334d5e (MD5) Previous issue date: 2017-08-08 / Paclitaxel is an antineoplastic drug used as a first line in the treatment of several solid tumors, particularly in breast, ovarian, lung, head and neck carcinomas. However, patients receiving paclitaxel treatment often develop a painful condition that occurs immediately after the treatment with this drug, known as acute pain syndrome associated with paclitaxel. Nevertheless, the mechanisms by which paclitaxel induces this painful condition is not yet known. The aim of this study was to investigate the involvement of mast cells and satellite glial cells in the acute pain syndrome induced by paclitaxel. Adult male wild-type mice (C57BL/6), SH mutant mice and TNFR1/R2, TLR4, IL-1R, IL-6 and CCR2 knockout mice were used. Acute pain syndrome was induced by intravenous paclitaxel (4 mg / kg, single dose). After administration of paclitaxel, mechanical and thermal sensitivity (cold) were assessed. The mechanical sensitivity was evaluated using von Frey filaments, measuring pressure in grams. The sensitivity to cold was evaluated with a stimulus of 10 °C (acetone) applied to the right hind paw, leading to agitation and paw elevation behaviors, as well as licking, measured in seconds. The heat sensitivity was assessed by the Hargreaves test, where an infrared light source is positioned under the animal's hind paw for 20s or until the animal exhibits a positive response (flinch or paw withdrawal), then the light source stop automatically. In addition, mast cell line culture and satellite glial cells (dorsal root ganglia primary culture) were stimulated with paclitaxel. Samples (plasma, sciatic nerve, dorsal root ganglia and spinal cord) were collected for determination of gene expression and cytokine levels (IL-1β, TNF-α, IL-6, MCP-1 and KC / CXCL1). Immunofluorescence (c-Fos, IL-6 and tryptase) was also performed. The concentration of cytokines/chemokines (IL-1β, TNF-α e IL-6, MCP-1 e KC/CXCL1) was also evaluated in the supernatant of mast cells and satellite glial cells. The results demonstrated that intravenous injection of paclitaxel significantly reduced (p < 0.05) the nociceptive threshold, inducing mechanical and thermal hyperalgesic responses following administration of paclitaxel. However, when assessing the thermal response to heat, it was found that paw withdrawal latency was not altered with paclitaxel treatment when compared to the control group. Immunofluorescence reaction for c-Fos in the dorsal root and spinal cord ganglia, demonstrated cell activation evidenced by an increased immunoexpression was observed in the groups treated with paclitaxel. Administration of paclitaxel caused a significant (p<0.05) increase in IL-1β, TNF-α, IL-6, MCP-1 and KC / CXCL1 levels. Mechanical and thermal cold hyperalgesia were significantly reduced (p <0.05) in SH animals (no mast cells) when compared to wild animals, and treatment with sodium cromoglycate (mast cell membrane stabilizer) was effective (p <0.05) in inhibiting mechanical and thermal hyperalgesia after the chemotherapic treatment. Pretreatment with sodium cromoglycate significantly (p<0.05) prevented the increase of cytokines and chemokines in mice treated with paclitaxel. In the SH mice treated with paclitaxel, no significant increase (p<0.05) of cytokines was observed. Paclitaxel stimulation resulted in a significant (p<0.05) increase in cytokines (TNF-α, IL-6) and chemokines (MCP-1) concentration in mast cell culture. In addition, immunofluorescence of the dorsal root ganglion demonstrated increased immunoexpression of tryptase and IL-6 after administration of paclitaxel. The results also showed that the TLR4 receptor was involved in the development of paclitaxel-induced hyperalgesia, since knockout animals to TLR4 receptor treated with this chemotherapic did not develop mechanical and thermal hyperalgesia. The results also demonstrated that, in the TLR4 knockout mice treated with paclitaxel, there was no significant increase (p <0.05) in cytokines and chemokines; and when compared to the group of WT mice, a significant reduction (p <0.05) in cytokine and chemokine levels was observed. In addition, paclitaxel caused a significant (p <0.05) increase of cytokines (TNF-α and IL-6) and chemokines (MCP-1 and KC/CXCL) in satellite glial cell culture and the deletion of the TLR4 receptor gene was able to prevent this increase in cytokine/chemokine levels. The study showed for the first time that mast cells and satellite glial cells are involved in the development of acute pain induced by paclitaxel in mice. In addition, the study revealed that the activation of mast cells and satellite glial cells is possibly due to the binding of paclitaxel to TLR4, inducing the release of cytokines/chemokines that contribute to the development of acute pain induced by paclitaxel. / Paclitaxel é um antineoplásico utilizado como primeira linha no tratamento de diversos tumores sólidos, particularmente em carcinomas de mama, ovário, pulmão, cabeça e pescoço. Entretanto, os pacientes que recebem tratamento com paclitaxel frequentemente desenvolvem dor que ocorre imediatamente após o tratamento com este fármaco, conhecida como síndrome da dor aguda associada ao paclitaxel. No entanto, os mecanismos pelos quais o paclitaxel induz essa condição dolorosa, ainda não são conhecidos. Neste estudo objetivou-se investigar o envolvimento de mastócitos e de células satélites gliais na síndrome de dor aguda induzida pelo paclitaxel. Para isso foram utilizados camundongos C57BL/6 (selvagens), camundongos que não expressam mastócitos (SH) e camundongos knockout TNFR1/R2; TLR4; IL-1R; IL-6 e CCR2 machos (20-25g). O modelo consiste na administração de paclitaxel por via intravenosa (4 mg/kg, dose única). Após a administração de Paclitaxel a sensibilidade mecânica foi avaliada utilizando filamentos de von Frey, mensurado em gramas de pressão. A sensibilidade ao frio foi avaliada com um estímulo 10 ºC (acetona) aplicado na pata traseira direita, observando-se comportamentos de agitação e elevação da pata, além de lambidas, mensurados em segundos. E a sensibilidade ao calor foi avaliada através do teste de hargreaves, onde uma fonte de luz infravermelha é posicionada sob a pata traseira do animal durante 20s ou até que o animal exiba resposta positiva (flinch ou retirada da pata), então a fonte de luz e para automaticamente. Além disso, foi realizada cultura de linhagem de mastócitos e de células satélites gliais (cultura primária de gânglio da raiz dorsal) que foram estimuladas com paclitaxel. Foram coletadas amostras (plasma, nervo isquiático, gânglios da raiz doral e medula espinal) para determinação da expressão gênica e dosagem dos níveis de citocinas/qumiocinas (IL-1β, TNF-α e IL-6, MCP-1 e KC/CXCL1). Também foi realizado imunofluorescência (c-Fos, IL-6 e triptase). A concentração de citocinas/quimiocinas (IL-1β, TNF-α e IL-6, MCP-1 e KC/CXCL1) também foi avaliada no sobrenadante das culturas de mástocitos e de células satélites gliais. Os resultados demonstraram que a injeção intravenosa de paclitaxel reduziu significativamente (p<0,05) o limiar nociceptivo, induzindo respostas hiperalgesicas mecânica e térmica ao frio após a administração de paclitaxel. No entanto, quando se avaliou a resposta térmica ao calor, verificou-se que a latência de retirada da pata não foi alterada com o tratamento com paclitaxel, quando comparadas ao grupo controle. A imunofluorescência para c-Fos nos gânglios da raiz dorsal e medula espinal demostrou ativação de celular evidenciado por aumento da imunoexpressão nos grupos tratado com paclitaxel. A administração de paclitaxel aumentou significativamente (p<0,05) as citocinas IL-1β, TNF-α e IL-6, MCP-1 e KC/CXCL1. A hiperalgesia mecânica e térmica ao frio foram reduzidas significativamente (p<0,05) em animais SH (não possuem mastócitos), quando comparado aos animais selvagens, bem como o tratamento com cromoglicato de sódio (estabilizador de membrana de mastócitos) foi eficaz em inibir significativamente (p<0,05) a hiperalgesia mecânica e térmica ao frio após o tratamento com o quimioterápico. O pré-tratamento com cromoglicato de sódio preveniu significativamente (p<0,05) o aumento de citocinas e quimiocinas em camundongos tratados com paclitaxel. Nos camundongos SH tratados com paclitaxel não foi observado aumento significativo (p<0,05) de citocinas. A estimulação com paclitaxel provocou aumento significativo (p<0,05) de citocinas e quimiocinas (TNF-α, IL-6 e MCP-1) em cultura de mastócitos. Além disso, a imunofluorescência, no gânglio da raiz dorsal, demonstrou um aumento da imunoexpressão de triptase (marcador de mastócito) e IL-6 após a administração de paclitaxel. Os resultados mostraram também que o receptor TLR4 está envolvido no desenvolvimento de hiperalgesia induzida por paclitaxel, pois o tratamento de animais knockout para o receptor TLR4 com este quimioterápico não foi capaz de desenvolver hiperalgesia mecânica e térmica nesses animais. Os resultados demonstram ainda, que nos camundongos knockout TLR4 tratados com paclitaxel não houve aumento significativo (p<0,05) de citocinas e quimiocinas. E quando comparados ao grupo de camundongos selvagens, observou-se significativa redução (p<0,05) dos níveis de citocina e quimiocina. Além disso, o paclitaxel causou aumento significativo (p<0,05) de citocinas (TNF-α e IL-6) e quimiocinas (MCP-1 e KC/CXCL1) em cultura de células satélites gliais e a deleção gênica para o receptor TLR4 foi capaz de impedir o aumento dos níveis de citocinas/quimiocinas. O estudo mostra, pela primeira vez, que mastócitos e células satélites gliais estão envolvidos no desenvolvimento de dor aguda induzida pelo paclitaxel em camundongos. Adicionalmente, o estudo revelou que a ativação de mastócitos e de células satélites gliais, possivelmente se dá pela ligação do paclitaxel ao TLR4, induzindo a liberação de citocinas/quimiocinas que, contribuem para o desenvolvimento de dor aguda induzida pelo paclitaxel.

Plants are abundant in cytochrome P450s constituting about 1% of their protein coding genes. Some of these P450s catalyze oxidation reactions in metabolic pathways that lead to valuable compounds, like the anticancer drug paclitaxel, the blue pigment indigo and the promising antileukemic agent indirubin. The promiscuous nature of P450 catalysis enables simultaneous production of indirubin and indigo from a common substrate, but it also decreases the yield of paclitaxel in both plants and heterologous hosts, respectively. In this thesis, the catalytic promiscuity of CYP725A4 from Taxus cuspidata and CYP71B102 from Isatis tinctoria were investigated. CYP725A4 and CYP71B102 are involved in the biosynthesis of paclitaxel and indigo/indirubin pathways, respectively. CYP725A4 is known to catalyze the hydroxylation of endotaxadiene to taxadiene-5α-ol (T5α-ol), a precursor to paclitaxel, while CYP71B102 catalyzes the production of indigo and indirubin via hydroxylation of indole. CYP725A4 exhibited catalytic promiscuity upon heterologous expression in Escherchia coli producing 5(12)-oxa-3(11)-cyclotaxane (OCT) and 5(11)-oxa-3(11)-cyclotaxane (iso-OCT) as major products, and T5α-ol as a minor product with trace amounts of unidentified monooxygenated taxanes. The presence of T5α-ol was confirmed by comparing its gas chromatography and mass spectroscopy (GC-MS) retention time and spectrum with a standard T5α-ol, while those of others were verified by matching mass spectra from previous studies. Coexpression of CYP725A4 with cytochrome P450 reductase, CPR (as either fused or separate proteins) and cytochrome b5 (Cb5) did not affect the ratios of OCT, iso-OCT, and T5α-ol, although Cb5 had an apparently negative impact on CYP725A4 activity. Attempts to modify the catalytic promiscuity of CYP725A4 were conducted by mutating key residues at the active site of the enzyme. A mutant V3741 increased the production of T5α-ol by ~10 fold, although it still supported the formation of OCT and iso-OCT as major products. The levels of these compounds in V374I were almost 45% less than in native CYP725A4. Site-directed mutagenesis was also performed on taxadiene synthase (TS) to find a mutant that only produced exotaxadiene, which could be provided to CYP725A4 as an alternative substrate. Among the TS mutants generated, none were capable of producing only exotaxadiene, but two of the TS mutants, Y684C and Q609E, produced a reasonable amount of exotaxadiene. However, coexpression of these mutants with CYP725A4 and TCPR continued to produce OCT and iso-OCT. When CYP71B102 was expressed in E. coli, indigo was the main product, while indirubin and 2-oxindole were minor products, as verified by high-performance liquid chromatography (HPLC). Half-strength terrific broth (TB) medium in combination with 5-aminolevulinic acid supplementation and isatin hydrolase coexpression altogether increased indigo formation, while supplementation with isatin and 2-oxindole increased indirubin formation. The results of this study showed that the catalytic promiscuity of CYP725A4 and CYP71B102 could be modulated by metabolic and enzyme engineering to increase the yield of commercially important compounds, like paclitaxel, indigo and indirubin.

Tumors induce immune dysfunction through the production of soluble factors that subvert macrophage (Mf) function to favor tumor growth. Previous studies suggested that tumor-induced immune cell dysfunction may be reversible through regimens that disrupt tumor cell suppressor mechanisms and concurrently promote tumoricidal activities. Because the antineoplastic agent paclitaxel (TAXOL) activates Mf function, we studied mechanisms of paclitaxel-mediated cytotoxic and immunostimulatory responses by tumor-induced Mfs. Although tumor-derived factors, including interleukin-10 and transforming growth factor-b1, modulate Mf response to activation signals, paclitaxel partly reverses tumor-induced Mf-mediated suppression of T-cell reactivity through enhanced production of the immunostimulatory cytokine interleukin-12 (IL-12). Concurrently, paclitaxel induces Mf cytotoxic and proinflammatory molecule production, including tumor necrosis factor-a and interleukin-1b. In contrast to its apparent immunotherapeutic effect on Mf populations, paclitaxel's cytostatic mechanisms suppress lymphocyte proliferation and function. We showed that IL-12 can reverse paclitaxel-mediated suppression of T-cell responses in vitro, establishing the foundation for a novel antitumor therapy using paclitaxel in combination with IL-12. We show that the administration of paclitaxel as a chemotherapeutic agent, followed by IL-12 as an immunotherapeutic agent to alleviate paclitaxel-mediated immunosuppression, prolongs survival, reduces tumor progression, and activates immune effector populations in a murine tumor model. These results are the first experimental evidence to suggest that paclitaxel and IL-12 are an effective antitumor modality. Collectively, these studies show that paclitaxel induces multiple antitumor mechanisms that can be enhanced with proper ancillary administration of immunotherapeutic cytokines. / Ph. D.

Paclitaxel is a natural occurring diterpene alkaloid originally isolated from the bark of Taxus brevifolia. It is now one of the most important chemotherapeutic agents for clinical treatment of ovarian and breast cancers. Recent clinical trials have also shown paclitaxel's potential for the treatment of non-small-cell lung cancer, head and neck cancer, and other types of cancers. While tremendous chemical research efforts have been made in the past years, which established the fundamental structure-activity relationships of the paclitaxel molecule, and provided analogs for biochemical studies to elucidate the precise mechanism of action and for the development of second-generation agents, many areas remain to be explored. In continuation of our efforts in the structure-activity relationships study of A-norpaclitaxel, five new analogs modified at the C-1 substituent and analogs with expanded B-ring or contracted C-ring have now been prepared. Preliminary biological studies indicated that the volume rather than functionality at the C-1 position plays a role in determining the anticancer activity by controlling the relative position of the tetracyclic ring system, which in turn controls the positions of the most critical functionalities such as the C-2 benzoyl, the C-4 acetate, and the C-13 side chain. The optimum conformation could possibly be modulated by ring contraction or expansion, as suggested by the improved activity of a B-lactone-A-norpaclitaxel analog. Chemical investigations were also carried out in the C-6 and C-7 positions and led to the synthesis of five new analogs. Of particular importance, 6a-hydroxy-paclitaxel, the major human metabolite of paclitaxel, was synthesized for the first time through a C-7 epimerization reaction. The availability of the major human metabolite through synthesis makes it possible to perform in vivo biological investigations on the metabolite, and it also offers an important opportunity for the production of standard HPLC samples of the metabolites which could be useful in the clinical monitoring of paclitaxel's disposition in human patients. Previous modifications at the C-4 position suggested that analogs with an acyl group other than an acetate at C-4 may exert similar activity to paclitaxel. Little was known, however, on the conformation-activity relationships of the C-4 position. In order to further explore the C-4 chemistry, a mild C-4 acylation method using acid as the acyl source was successfully developed. The new method was exemplified by the synthesis of water-soluble paclitaxel analogs with hydrophilic functional groups at the terminal of the C-4 acyl moiety. This method should be applicable to a variety of similar carboxylic acids and offer an alternative or even better approach for the preparation of C-4 modified paclitaxel analogs. Lastly, in addition to the extension of paclitaxel analog library, specially designed analogs have been sought to probe the active conformation of paclitaxel. An analog that has a bridge to tie up the C-4 acyl group with an inert position would be useful for this purpose. With successful demonstration of the above C-4 acylation method, combined with the well established C-6 chemistry, the synthesis of such a novel C-4 and C-6 bridged paclitaxel analog was completed. / Ph. D.

The western yew, Taxus brevifolia, was for many years the source of the important anticancer drug taxol, but it also contains many other natural taxoids. These compounds are of interest both from a structural viewpoint and also as a starting point for the synthesis of paclitaxel analogs. As a complement to our ongoing studies on the chemistry of paclitaxel and on its structure-reactivity relationships, we have investigated T. brevifolia extracts and have isolated two new taxoids. These are the A-nortaxol analog 7,13-deacetyl-9,10-debenzoyltaxchinin C 2.1 and 9-deacetyl-9-benzoyl-10-debenzoylbrevifoliol 2.4. The structures were elucidated by spectral methods, including extensive 2D nmr techniques. An approach to the synthesis of a novel A-nortaxol analog from one of the new compounds has been developed. / Master of Science

The conformation of paclitaxel in the bound state on the protein has been proposed to be the T-taxol conformation, and paclitaxel analogs constrained to the T-taxol conformation proved to be significantly more active than paclitaxel in both cytotoxicity and tubulin polymerization assays, thus validating the T-taxol conformation as the tubulin-binding conformation. In this work, eight compounds containing an aza-tricyclic moiety as a mimic of the baccatin core of paclitaxel have been designed and synthesized as water-soluble simplified paclitaxel analogs, among which 3.50-3.52 and 3.55 were conformationally constrained analogs designed to bind to the paclitaxel binding site of tubulin, based on their similarity to the T-taxol conformation. The open-chain analogs 3.41-3.43 and 3.57 and the bridged analogs 3.50-3.52 and 3.55 were evaluated for their antiproliferative activities against the A2780 cell lines. Analogs 3.50-3.52 and 3.55 which were designed to adopt the T-taxol conformation showed similar antiproliferative activities compared to their open-chain counterparts. They were all much less active than paclitaxel. In the second project, a series of paclitaxel analogs with various thio-containing linkers at C-2′ and C-7 positions were designed and synthesized in our lab. These analogs were attached to the surfaces of gold nanoparticles by CytImmune Sciences for the development of mutifunctional tumor-targeting agents. The native analogs and the gold bound analogs were evaluated for their antiproliferative activities against the A2780 cell line. All the compounds tested showed comparable or better activities than paclitaxel. Stability studies were performed for selected analogs in hydrolysis buffer, which showed that the analogs released paclitaxel in buffer over time. In the third project, the synthesis of a conformationally constrained paclitaxel analog which was designed to mimic the REDOR-taxol conformation was attempted. Two synthetic routes were tried and significant progress was made toward the synthesis of the conformationally constrained analog. However, both of the current synthetic routes failed to produce the key intermediate that would serve as the precursor for a ring-closing metathesis reaction to furnish the macrocyclic ring. / Ph. D.

El objetivo de este estudio fue detectar la frecuencia de los polimorfismos de nucleótido simple (SNP) CYP2C8*2 y CYP2C8*3 en genes CYP2C8 de pacientes con cáncer de mama que recibieron quimioterapia neoadyuvante con paclitaxel en el Instituto Nacional de Enfermedades Neoplásicas (INEN). Además, se asoció la presencia de estos SNP con la respuesta terapéutica y la toxicidad. Se incluyó en el estudio 39 mujeres con diagnóstico reciente de cáncer de mama localmente avanzado que acudieron al consultorio de oncología médica del INEN entre marzo y diciembre del 2013, quienes firmaron el consentimiento informado previo a la ejecución del estudio. Se tomaron muestras de sangre venosa para extraer el ADN genómico y se amplificaron regiones específicas del gen CYP2C8 mediante la reacción en cadena de la polimerasa (PCR) con cebadores diseñados para detectar el SNP CYP2C8*2 en el exón 5 y el SNP CYP2C8*3 en el exón 8. Los productos amplificados fueron cortados con las enzimas de restricción BClI y PdmI (XmnI) para CYP2C8*2 y CYP2C8*3 respectivamente. La información clínica y patológica de las pacientes se obtuvo de las historias almacenadas en el archivo de historias clínicas del INEN mediante una ficha de recolección de datos. El SNP CYP2C8*2 no fue detectado en la población estudiada. El SNP CYP2C8*3 fue encontrado en 3 pacientes (7,7 %), dos homocigotos y un heterocigoto, con una frecuencia alélica de 6,4 %. Así mismo, se encontró que 56,5 % de las pacientes presentó neuropatía; 10,3 % leucopenia; 20,5 % anemia; 2,6 % trombocitopenia; 66,7 % incremento de los niveles de TGP y 46,2 % incremento de los niveles de TGO. No se encontró asociación entre el genotipo CYP2C8*3 y el riesgo de neuropatía inducida por paclitaxel (p>0,05). Las pacientes que presentaron el genotipo AA para el SNP CYP2C8*3 (1196 A>G) mostraron diferencias significativas en la reducción del tamaño clínico del tumor y del compromiso ganglionar después de la quimioterapia con paclitaxel (p<0,05). Sin embargo, las pacientes con los genotipos AG y GG para este SNP, no mostraron diferencias significativas. / --- The aim of this study was to detect the frequency of CYP2C8*2 and CYP2C8*3 single nucleotide polymorphisms (SNP) in CYP2C8 genes of patients with breast cancer who received neoadjuvant chemotherapy with paclitaxel at the National Institute of Neoplastic Diseases (INEN). Furthermore, the presence of these SNP with therapeutic response and toxicity were associated. In the study were included 39 women with newly diagnosed of locally advanced breast cancer who attended the oncology doctor’s office of the INEN between March and December 2013. All the patients signed informed consent before study entry. Venous blood samples were taken to extract the genomic DNA and specific regions of the CYP2C8 gene were amplified by Polymerase Chain Reaction (PCR) with primers designed to detect the CYP2C8*2 SNP in exon 5 and CYP2C8*3 SNP in exon 8. The amplified products were cut with restriction enzymes BclI and PdmI (XmnI) for CYP2C8*2 and CYP2C8*3, respectively. Clinical and pathological information of the patients was obtained from the medical records stored at the INEN. The CYP2C8*2 SNP was not detected in the study population. The CYP2C8*3 SNP was found in 3 patients (7.7%), two homozygotes and one heterozygote, with an allele frequency of 6.4%. Also, it was found that 56.5% of patients had neuropathy; 10.3% leukopenia; 20.5% anemia; 2.6% thrombocytopenia; 66.7% increase in ALT levels and 46.2% increase in AST levels. No association between CYP2C8*3 genotype and risk of paclitaxel induced neuropathy (p> 0.05) was found. The patients who had the AA genotype for CYP2C8*3 (1196 A>G) showed significant differences in the reduction of clinical tumor size and nodal involvement after chemotherapy with paclitaxel (p <0.05). However, patients with AG and GG genotypes for this SNP showed no significant differences. Keywords: Breast cancer, CYP2C8 gene, SNP, PCR-RFLP.

Cancer cells utilise glycolysis to produce lactate, even in the presence of sufficient levels of oxygen. Excess lactate is removed from cancer cells by MCT1 and MCT4, to prevent intracellular acidosis, apoptosis and to aid the continuous glycolytic flux. MCT1 and MCT4 are over-expressed in many types of human cancers, which correlates with reduced overall survival and increased treatment resistance. The potential role of MCT1 and MCT4 in two EOC cell lines (Skov3 and OV90) was investigated in this study. MCT1 was expressed at similar levels in Skov3 and OV90 cells. Therefore, stable cell lines over-expressing MCT1 were produced using both cell lines. MCT4 was expressed at high levels in Skov3 cells, but very low levels in OV90 cells. Therefore, a stable cell line with MCT4 silencing under the inducible control of doxycycline was produced using Skov3 cells, and a stable cell line to over-express MCT4 was produced using OV90 cells. The consequences of these genetic modifications on the metabolic phenotype, metastatic abilities and the sensitivity of cell lines to treatment with Carboplatin and Paclitaxel, were assessed in normoxia and 1 % hypoxia and 0.1 % hypoxia. Over-expressing MCT1 in Skov3 cells, had no effect on their metabolic phenotype or the sensitivity to treatment with Carboplatin and Paclitaxel. However, over-expressing MCT1 in Skov3 cells significantly enhanced their metastatic abilities, which correlated with reduced focal adhesion size. Silencing MCT4 in Skov3 cells, had no effect on the use of glycolysis, sensitivity to treatment with Carboplatin and Paclitaxel, or their metastatic abilities. However, following MCT4 silencing there was a significant increase in the levels of intracellular ROS. Over-expressing MCT1 in OV90 cells, had no effect on lactate levels or intracellular ROS. However, there was a significant reduction in both their glycolytic activity and mitochondrial mass. Furthermore, over-expressing MCT1 in OV90 cells, increased their resistance to treatment with Paclitaxel, which correlated with increased Pgp and LDHA expression. Over-expressing MCT4 in OV90 cells, caused an increase in the use of glycolysis and increased cell survival in hypoxia. There was also a significant enhancement in the metastatic abilities of these cells following the over- expression of MCT4, which correlated with reduced focal adhesion size. Furthermore, over-expressing MCT4 in OV90 cells, increased their resistance to treatment with Paclitaxel, which correlated with an increase in the expression of Pgp and LDHA.In summary, the findings of this study revealed that MCT1 and MCT4 play a significant role in the biological function of Skov3 and OV90 cells. High expression levels of MCT4 correlated with an increase in glycolysis and cell survival in hypoxia. Whereas high expression levels of MCT1 and MCT4 in correlated with an increase in the metastatic abilities, as well as with Paclitaxel resistance and increased Pgp expression.

Orientador: Ramon Kaneno / Resumo: A nanomedicina é o ramo da nanotecnologia que investiga a aplicação de novos materiais para a área medica e biomédica. Os nanotubos de carbono (CNT) são conhecidos pela sua aplicação em diversas áreas de pesquisas, como nos campos óptico e eletrônico. No campo biomédico, os CNT podem auxiliar no diagnóstico e tratamento de doenças, como por exemplo: no desenvolvimento de novos biossensores e entrega controlada de drogas às células doentes. Neste cenário, apresentamos uma revisão literária dos CNT aplicados na área biomédica, demonstrando os principais avanços e enfatizando seu potencial de uso como nanocarreador de agentes antineoplásicos para células tumorais. Na sequência, apresentamos os dados experimentais de um estudo em que CNT foram modificados para transportar paclitaxel (PTX) mimetizados com anticorpos anti-PSMA para endereça-los as células de câncer prostático humano. Nossos resultados demonstram a eficiência da metodologia empregada para a incorporação de paclitaxel nos CNT, bem como para o revestimento com anticorpos monoclonais. Mais importante foi a observação de que a preparação final contendo PTX e o anticorpo anti-PSMA (CNT-PTX-Ab) mostrou-se mais eficiente que o PTX puro em atacar células tumorais LNCaP. Ao final, apresentamos os dados de um estudo adicional em que os CNT carregados com PTX foram submetidos com glicose. Considerando que células tumorais apresentam metabolismo mais elevado que as células normais hipostenizamos que o açúcar po... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Inflammatory cytokines and chemokines are known to promote tumor cell survival, invasion, the formation of blood and lymphatic vessels, and hence, metastasis. We previously showed that a pro-inflammatory pathway regulated by Toll-like Receptor-4 (TLR4) can be activated in human breast cancer (BC) cell lines by a clinical chemotherapeutic drug, paclitaxel (PXL). Prior data showed that PXL treatment of TLR4+ tumors in vivo increased inflammation and tumor spread. Here, we used two BC models based on MDA-MB-231 and HCC1806 cell lines. Transcript expression of 123 cytokines in vitro and in vivo was determined by qRT-PCR. We found that 18 and 26 cytokines were upregulated by nanoparticle albumin-bound paclitaxel (nab-PXL) in 231TLR4+ cells and in 1806TLR4+ cells, respectively. Upregulation of cytokines was observed in cultured cells and in tumor models in vivo. Furthermore, fourteen cytokines (11.3% of total) were induced by nab-PXL in both tumor models suggesting that these targets are upregulated by PXL regardless of genetic makeup of tumor cells. We also confirmed the expression of these cytokines on protein level by ELISA. We found that expression of CCL20 and CXCL1 proteins is consistent with transcript expression detected by qRT-PCR. Taken together, CCL20 and CXCL1 can be the potential targets for further study, and they may have the capacity to recruit myeloid-derived lymphatic endothelial cell progenitors to the tumor site to promote lymphangiogenesis in breast cancer.