Thesis (M. Sc. (Biochemistry)) -- University of Limpopo, 2021 / Plant-derived products have been used for years in the treatment of various ailments with low or no side effects. Thus, screening of medicinal plants for potential anticancer activity, in vitro, could help identify plant extracts or compounds that can be developed for use as anticancer agents with less or no side effects. The aim of this study was to investigate the probable anticancer effects and induced mechanism of action of Momordica balsamina crude leaf acetone extract in lung A549 cancer cells. The effect of the extract on cell viability, proliferation and cell division cycle were determined using Muse count & viability, Ki67 proliferation and cell cycle assay kits, respectively. The presence of biochemical and morphological features associated with apoptosis were analysed by Muse annexin-V & dead cell assay kit and Acridine orange/Ethidium bromide dual staining. The effect of the extract on the mRNA expression levels of cell cycle regulatory genes was determined using RT PCR. Proteome profiler antibody array was used to determine the effect of the extract on the protein expression levels of apoptosis regulatory genes. The findings revealed that the crude leaf acetone extract of M. balsamina decreased the percentage viability of lung A549 cells with less effect on the percentage viability of normal cells (KMST-6). Furthermore, a significant anti-proliferative effect in extract treated A549 cells was observed. Characteristic nuclear and morphological features of apoptosis such as chromatin and nuclear condensation, externalisation of phosphatidylserine and loss of cell membrane function were observed in A549 cells treated with the extract. Although there was no relative upregulation of Bax and Bad protein expression, a downregulation of the Bcl-xl and Bcl-2 protein expression was observed in extract-treated cells. This led to the release of Cytochrome c and HTRA2/Omi leading to pro-caspase-3 cleavage. Furthermore, presence of HTRA2/Omi in the cytosol inhibited the functions of IAPs such as XIAP and cIAP1/2. Phosphorylation of p53 at different serine residues led to upregulated protein expression levels of p27/Kip1 protein which resulted in the cell division cycle arrest at G0/G1-phase. Reverse transcriptase polymerase chain reaction results showed that the extract modulated mRNA expression levels of p53, p21, cyclin B and cdc2 genes. In summary, M. balsamina extract induced cell division cycle arrest and apoptosis in A549 cells through intrinsic apoptosis pathway via p53-mediated mechanism. / South African Medical Research Council (SAMRC)

Indiana University-Purdue University Indianapolis (IUPUI) / Breast cancer remains the most prevalent malignancy diagnosed in women. More than two thirds of all diagnosed breast cancers are estrogen receptor (ER)-positive and are dependent on estrogen signaling. Drugs for the treatment of ER-positive breast cancer can be divided into three classes: selective estrogen receptor modulators (SERMs), selective estrogen receptor down-regulators (SERDs) and aromatase inhibitors (AIs). However, the efficacy and safety of SERMs, SERDs and AIs are compromised by side effects or tumor resistance. One possible way of improving treatment efficacy and safety profiles is to develop agents with dual aromatase inhibitory and ER modulatory activity. Over the past 30 years, tamoxifen, a SERM, has become the most widely used drug for the adjuvant treatment of breast cancer. The metabolism of tamoxifen has a complex profile involving both active and inactive metabolites, among which endoxifen, 4-hydroxytamoxifen (4-HT) and norendoxifen (Nor) have been shown to have ER modulatory activity. Previous studies have also shown that norendoxifen is a potent AI in vitro. These preliminary studies support the utilization of tamoxifen metabolites as lead compounds for the development of dual AI/SERM(D) agents. Hydroxynorendoxifen (Hdn) was identified as a novel tamoxifen metabolite, with an average plasma concentration of 0.82 nM. Nor and Hdn were potent and relatively selective AIs, with Kis of 70 nM and 20 nM, respectively. Nor and Hdn have high binding affinity for ER-α and ER-β, with EC50 values less than 35 nM. Nor and Hdn can inhibit breast cancer cell proliferation with high potency, with IG50s of 25 nM and 9 nM, respectively. Nor and Hdn can suppress progesterone receptor (PGR) mRNA expression level by reducing it by 68% and 86%. Moreover, a series of Nor analogues were shown to have both potent aromatase inhibitory activity and high ERs binding affinity. Results from this dissertation will contribute to three aspects: 1) the identification of Hdn as a tamoxifen metabolite illustrated a more comprehensive metabolism profile of tamoxifen; 2) the data suggest Nor and Hdn possess dual aromatase inhibitory and ER antagonistic activity; 3) a series of Nor analogues were characterized as lead compounds for the development of dual AI/SERM(D) agents.

No description available.

No description available.

Abstract : Glioblastoma is the most common and aggressive brain cancer in adults. The current standard-of-care treatment includes surgical resection, radiation therapy with concomitant and adjuvant temozolomide (TMZ) chemotherapy. However, the addition of TMZ to radiation therapy only increased the median survival time (MeST) by 2.5 months. This limited improvement is partially attributable to the low accumulation of chemotherapeutic drugs in the brain tumor due to the blood-brain barrier (BBB). Thus, new delivery methods such as intra-arterial, BBB disruption and convection-enhanced delivery (CED) have been proposed to overcome this limitation. Besides, timing tumor irradiation to coincide with the maximal concentration of platinum-DNA adducts could result in improved tumor control. In this study, CED of cisplatin and oxaliplatin, their respective liposomal formulations Lipoplatin™, Lipoxal™, and carboplatin with or without 15 Gy of radiation therapy has been carried out in F98 glioma bearing Fischer rats to assess their toxicity and MeST. The amount of platinum-DNA adducts in the tumor at 4 h and 24 h after CED was measured and irradiation was administered at these two different time periods to test the concomitant effect. In addition, four liposomal carboplatin formulations with different chemo-physical properties were prepared and their toxicity and MeST were also evaluated in this animal model. Among the tested platinum drugs, carboplatin and Lipoxal™ demonstrated a highest maximum-tolerated dose of 25 µg and 30 µg respectively. CED of carboplatin showed the longest MeST of 38.5 days, and increased to 54.0 days with the addition of 15 Gy radiation therapy. However, radiation at 4 h after CED of either oxaliplatin or carboplatin did not show any survival improvement when compared to radiation at 24 h, although the quantity of platinum-DNA adducts at 4 h was higher than at 24 h after CED. In the four liposomal carboplatin formulations, anionic pegylated liposomal carboplatin showed the longest MeST of 49.5 days, due to its longer tumoral retention time and probably larger distribution volume in the brain. / Résumé : Le glioblastome est le cancer primaire du cerveau le plus courant et agressif chez l’adulte. Le traitement standard comprend la résection chirurgicale, la radiothérapie et la chimiothérapie concomitante et adjuvante avec le témozolomide(TMZ). L'addition de TMZ combinée la radiothérapie a augmenté la survie médiane (MeST) de 2,5 mois. Cette faible amélioration est partiellement due à l'accumulation limitée de médicaments chimiothérapeutiques dans la tumeur cérébrale à cause de la barrière hémato-encéphalique (BBB). Ainsi, de nouvelles méthodes comme l’injection intraartérielle, la rupture osmotique de la barrière hémato-encéphalique, la livraison augmentée par convection (CED) ont été suggérées pour surmonter ce problème. En plus, l’optimisation de l’irradiation de la tumeur lorsque le maximum d’adduits platine-ADN est atteint pourrait aboutir à un meilleur contrôle de la tumeur. Dans cette étude, nous avons injecté par CED le cisplatine, l’oxaliplatine, avec leur formulation liposomale Lipoplatin™, Lipoxal™ ainsi que le carboplatine avec ou sans radiation de 15 Gy. La toxicité et le temps de MeST ont été mesurés chez des rats Fischer porteurs du gliome. La quantité d'adduits platine-ADN dans la tumeur a été mesurée 4 h et 24 h après CED. L’irradiation de la tumeur a été effectuée à ces deux temps pour tester l'effet concomitant. En plus, quatre formulations liposomales de carboplatine avec différentes propriétés chimiophysiques ont été préparées et leur toxicité et MeST combiné à la radiation ont également été évalués. Parmi les drogues de platine testées, le carboplatine et Lipoxal™ ont démontré respectivement la dose maximale tolérée la plus élevée, soit 25 µg et 30 µg. La MeST du carboplatine était la plus longue avec 38,5 jours qui a augmenté à 54,0 jours avec l’addition de 15 Gy de radiothérapie. Toutefois, l’irradiation à 4 h après CED effectuée avec l'oxaliplatine et le carboplatine n'a pas amélioré la MeST comparé à l’irradiation à 24 h, bien que la quantité d'adduits platine-ADN à 4 h était supérieure à celle mesurée à 24 h après CED. Pour les quatre formulations liposomales de carboplatine, celle pégylée négatif a démontré la plus longue MeST, soit 49,5 jours.

<p>Hemioterapija koja se koristi za lečenje karcinoma utiče i na kardiovaskularni sistem. Ciljevi&nbsp; istraživanja&nbsp; su: u tvrditi uticaj kardiotoksičnosti&nbsp; na&nbsp; reživljavanje&nbsp; bolesnika&nbsp; sa uznapredovalim stadijumom NSCLC; utvrditi učestalost pojave kardiotoksičnosti kod bolesnika koji su lečeni hemioterapijom prve linije (gemcitabin/cisplatin i paclitaxel/carboplatin) sa i bez prethodnih kardiovaskularnih oboljenja i utvrditi učestalost pojave kardiotoksičnosti u toku primene protokola docetaxel/cisplatin kao hemioterapije druge linije, u odnosu na primenu protokola gemcitabin/ cisplatin i paclitaxel/carboplatin, kao terapije prve linije. Istraživanjem je obuhvaćeno 270 bolesnika sa citolo&scaron;ki ili patohistolo&scaron;ki dokazanim NSCLC kliničkog stadiju ma III i IV.&nbsp; Dobijeni su rezultati koji ukazuju da je preživljavanje bolesnika u III i IV stadijumu NSCLC koji su imali pojavu kardiotoksičnosti tokom hemioterapije prve i druge linije kraće u odnosu na bolesnike bez pojave kardiotoksičnosti, sa statističkom značajno&scaron;ću nakon prvog, drugog, četvrtog ciklusa hemioterapije i nakon &scaron;est meseci (p=0.004, p=0.020, p=0.030 i p&lt;0.0005. respektivno). Kardiotoksičnost kod bolesnika u III i IV stadijumu NSCLC koji su primali hemioterapiju prve linije prema protokolu gemcitabin/cisplatin se če&scaron;će javila ukoliko su imali prethodne kardiovaskularne bolesti, ali statistička značajnost nije utvrđena. Kardiotoksičnost kod bolesnika u III i IV stadijumu NSCLC koji su primali hemioterapiju prve linije prema protokolu paclita xel/carboplatin se če&scaron;će javila ukoliko su imali prethodne kardiovaskularne bolesti, a statistička značajnost utvrđena prilikom prvog kontrolnog pregleda kod bolesnika u III stadijumu (p=0.037). Kod bolesnika u III i IV stadijumu NSCLC koji su primali hemioterapiju prve linije prema protokolima gemcitabin/cisplatin paclitaxel / carboplatin kardiotoksičnost se če&scaron;će javila ukoliko su imali prethodna kardiovaskularna oboljenja, ali je statistička značajnost ustanovljena samo pri prvom kontrolnom pregledu , (p=0.022). Kod bolesnika koji su primali hemioterapiju druge linije kardiotoksičnost značajno če&scaron;će javila u toku prvog ciklusa hemioterapije (p=0.049) u odnosu&nbsp; na&nbsp; bolesnike&nbsp; koji&nbsp; su&nbsp; primali hemioterapiju&nbsp; prve&nbsp; linije.&nbsp; Kod bolesnika koji su imali prethodne kardiovaskularne bolesti u toku druge linije hemioterapije kardiotoksičnost se statistički značajno če&scaron;će javila u odnosu na prvu liniju hemioterapije u toku četvrtog ciklusa hemioterapije (p=0.020). Uspostavljanje ravnoteže između efektivnosti hemioterapije i rizika od o&scaron;tećenja kardiovaskularnog sistema zahteva blisku saradnju onkologa i kardiologa , sa ciljem kreiranja individualne terapije za svakog bolesnika.</p> / <p>Lung&nbsp; cancer&nbsp; chemotherapy&nbsp; affects&nbsp; the&nbsp; cardiovascular&nbsp; system&nbsp; as&nbsp; well. The research&nbsp; objectives&nbsp; were&nbsp; to&nbsp; establish:&nbsp; the&nbsp; effects&nbsp; of&nbsp; cardiotoxicity&nbsp; on&nbsp; the survival of advanced NSCLC patients;&nbsp; the frequency of cardiotoxicity in the patients&nbsp; treated&nbsp; with&nbsp; the&nbsp; first - line&nbsp; chemotherapy&nbsp; (gemcitabine/cisplatin&nbsp; and paclitaxel/carboplatin),&nbsp;&nbsp; with&nbsp;&nbsp; or&nbsp;&nbsp; without&nbsp;&nbsp; the&nbsp;&nbsp; history&nbsp;&nbsp; of&nbsp;&nbsp; cardiovascular comorbidities, and the frequency of cardiotoxicity registered in the course of the&nbsp; second - line&nbsp; chemotherapy&nbsp; with docetaxel/cisplatin,&nbsp; as&nbsp; compared&nbsp; to&nbsp; the first - line chemotherapy&nbsp; with gemcitabine/cisplatin and paclitaxel/carboplatin.&nbsp;&nbsp;&nbsp; The&nbsp;&nbsp;&nbsp; investigation&nbsp;&nbsp;&nbsp; included&nbsp;&nbsp;&nbsp; 270&nbsp;&nbsp;&nbsp; patients&nbsp;&nbsp;&nbsp; with citologically&nbsp; or histopathologically&nbsp; confirmed&nbsp; NSCLC&nbsp; at&nbsp; the&nbsp; clinical&nbsp; stages III&nbsp; and&nbsp; IV. The&nbsp; obtained&nbsp; research&nbsp; results&nbsp; suggest&nbsp; the&nbsp; patients&nbsp; with&nbsp; stage&nbsp; III and IV NSCLC who developed&nbsp; cardiotoxicity in the course of&nbsp; the first &ndash; and second - line&nbsp;&nbsp; chemotherapy&nbsp;&nbsp; had&nbsp;&nbsp; a&nbsp;&nbsp; shorter&nbsp;&nbsp; survival&nbsp;&nbsp; than&nbsp;&nbsp; those&nbsp;&nbsp; without cardiotoxicity,&nbsp; with&nbsp; the&nbsp; statistical&nbsp; significance&nbsp; registered&nbsp; after&nbsp; the&nbsp; first, second,&nbsp; and&nbsp; fourth&nbsp; chemotherapy&nbsp; course,&nbsp; as&nbsp; well&nbsp; as&nbsp; six&nbsp; months&nbsp;&nbsp;&nbsp; later (p=0.004,&nbsp; p=0.020,&nbsp; p=0.030&nbsp; and&nbsp; p&lt;0.0005&nbsp; respectively). Stage&nbsp; III&nbsp; and&nbsp; IV NSCLC&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; patients&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; receiving&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; first - line&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; chemotherapy&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; with gemcitabine/cisplatin developed cardiotoxicity more frequently if they had a former history of cardiovascular diseases, but with no statistical significance registered. Stage&nbsp; III and IV NSCLC patients on the&nbsp; first - line&nbsp; chemotherapy protocol&nbsp;&nbsp;&nbsp; with&nbsp;&nbsp;&nbsp; paclitaxel/carboplatin&nbsp;&nbsp;&nbsp; developed&nbsp;&nbsp;&nbsp; cardiotoxicity&nbsp;&nbsp;&nbsp; more frequently&nbsp; if&nbsp; they&nbsp; had&nbsp; a&nbsp; former&nbsp; history&nbsp; of&nbsp; cardiovascular&nbsp; diseases,&nbsp; and&nbsp; the&nbsp; statistical significance was registered at the first control examination in stage III&nbsp; NSCLC&nbsp; patients&nbsp; (p=0.037).&nbsp; Stage III&nbsp; and&nbsp; IV&nbsp; NSCLC&nbsp; patients&nbsp; receiving the&nbsp;&nbsp; first-line&nbsp;&nbsp; chemotherapy&nbsp;&nbsp; protocols&nbsp;&nbsp; with&nbsp;&nbsp; gemcitabine/cisplatin&nbsp;&nbsp; and paclitaxel/carboplatin&nbsp; developed&nbsp; cardiotoxicity&nbsp; more&nbsp; frequently&nbsp; if&nbsp; they&nbsp; had former cardiovascular diseases, but the statistical significance was registered at&nbsp;&nbsp; the&nbsp;&nbsp; first&nbsp;&nbsp; control&nbsp;&nbsp; examination&nbsp;&nbsp; only, one&nbsp;&nbsp; month&nbsp;&nbsp; after&nbsp;&nbsp; chemotherapy application (p=0.022). The&nbsp; patients receiving the&nbsp; second - line&nbsp; chemotherapy developed&nbsp; cardiotoxicity&nbsp; much&nbsp; more&nbsp; often&nbsp; during&nbsp; the&nbsp; first&nbsp; chemotherapy course (p=0.049),&nbsp;&nbsp; as&nbsp;&nbsp; compared&nbsp;&nbsp; to&nbsp;&nbsp; the&nbsp;&nbsp; patiens&nbsp;&nbsp; receiving&nbsp;&nbsp; the&nbsp;&nbsp; first - line chemotherapy.&nbsp; Among&nbsp; the&nbsp; patients&nbsp; with&nbsp; a&nbsp; former&nbsp; history&nbsp; of&nbsp; cardiovascular diseases,&nbsp;&nbsp;&nbsp; those&nbsp;&nbsp;&nbsp; receiving&nbsp;&nbsp;&nbsp; the&nbsp;&nbsp;&nbsp; second &ndash; line&nbsp;&nbsp;&nbsp; chemotherapy&nbsp;&nbsp;&nbsp; developed cardiotoxicity&nbsp; during&nbsp; the&nbsp; fourth&nbsp; chemotherapy&nbsp; course&nbsp; significanly&nbsp; more freequently&nbsp;&nbsp; than&nbsp;&nbsp; the&nbsp;&nbsp; patients&nbsp;&nbsp; on&nbsp;&nbsp; the&nbsp;&nbsp; same&nbsp;&nbsp; course&nbsp;&nbsp; of&nbsp;&nbsp; the&nbsp;&nbsp; first-line chemotherapy&nbsp; (p=0.020). To&nbsp; achieve&nbsp; the&nbsp; balance&nbsp; between&nbsp; chemotherapy efficacy&nbsp; and&nbsp; the&nbsp; risk&nbsp; of&nbsp; the&nbsp; cardiovascular&nbsp; system&nbsp; damage&nbsp; requires&nbsp; a&nbsp; close cooperation of an oncologist and a cardiologist, aimed at designing a unique, individual therapy for each patient.</p>

O câncer é uma das doenças que mais acometem a população no mundo. Dessa forma, estudar suas terapêuticas é importante para o entendimento dos mecanismos e alvos biológicos por detrás da doença. Apesar dos tratamentos convencionais apresentarem uma boa eficácia, eles também provocam respostas indesejadas, como danos moleculares, resistência de células neoplásicas e efeitos colaterais fortes, colaborando para uma maior taxa de reincidência de neoplasias e mortalidade de pacientes. Sendo assim, a busca por alternativas é um importante desafio da Ciência Moderna para aprimorar e/ou substituir esses tratamentos. As plantas medicinais, como alternativa, são o foco de muitos estudos voltados ao câncer. O objetivo do presente trabalho foi avaliar o efeito citotóxico de 59 extratos em linhagens celulares humanas de câncer de mama (MDA-MB-231 e MCF7), próstata (PC-3 e DU 145) e fígado (HepG2). Foi realizada, inicialmente, uma triagem dos extratos por MTT em duas diluições 100x e 1000x para análise da viabilidade celular desses extratos. No total, 35 extratos obtiveram uma resposta para, pelo menos, uma das linhagens de câncer. A próxima etapa envolveu estudar os extratos pré-seletivos na triagem através de curvas-resposta quantificando a seletividade desses extratos para cada linhagem testada. Para essa etapa, foram selecionados 31 extratos. No câncer de mama, para a linhagem MDA-MB-231 nove extratos foram seletivos, e para MCF7 foram seis extratos. No câncer de próstata, para a linhagem PC-3, quinze extratos foram seletivos, e para DU 145 dezesseis extratos foram seletivos, mostrando uma maior sensibilidade do câncer de próstata comparado ao câncer de mama e fígado (HepG2 - sete extratos seletivos) em relação aos extratos testados. De todos os resultados apresentados, algodão de seda (Calotropis procera), camomila (Matricaria chamomilla), casca de anta (Drimys winteri), erva de São Caetano (Momordica charantia L.), estigmas de milho (Zea mays), graviola (Annona muricata), ipê roxo (Tabebuia sp.), malva - folhas (Malva sylvestris) e unha de gato (Uncaria tomentosa) foram os extratos mais amplamente significativos atingindo as linhagens celulares apresentando altos índices de seletividade. Com a realização desse trabalho podemos concluir que os extratos apresentam atividade antiproliferativa e seus fitoquímicos podem ser utilizados no estudo de novos fitoterápicos. O próximo passo é elucidar os mecanismos moleculares onde eles atuam. / Cancer is one of the most common diseases overworld. Studying the therapeutics of it is important to understand the biological mechanisms and targets behind this disease. Although conventional treatments show a good outcome against some types of cancer, they also currently cause undesired responses, such as molecular damage, neoplastic cell resistance and strong side effects, increasing recurrence of neoplasms, metastasis formation, and patient mortality. Therefore, the search for new alternatives is a challenge for Modern Science to improve or replace conventional treatments. In view of their antiproliferative effects medicinal plants have become the focus of many cancer studies as an alternative. The aim of the present study was to evaluate the cytotoxic and antiproliferative effect of 59 plant extracts in human cancer cell lines as breast cancer (MDA-MB-231 and MCF7), prostate cancer (PC-3 and DU 145) and liver cancer (HepG2). Initially, the extracts were screened in two different dilutions 100x and 1000x by MTT to analyze the cellular viability and cytotoxicity effects of them. To 59 extracts analyzed, 35 were effective against at least one of the tested lineages. The next step involved studying those pre-selective extracts through response curves to quantify the selectivity of these extracts for each cell lineage tested. For this stage, 31 extracts were selected. In breast cancer, for MDA-MB-231, nine extracts were selective and for MCF7 were six extracts. In prostate cancer, for PC-3, fifteen extracts were selective and for DU 145 were sixteen extracts. For liver cancer (HepG2) only seven extracts were selective. Comparing all the cancer lineages we can see a greater sensitivity of prostate cancer lineages compared to breast cancer and liver cancer in response of these tested extracts. Of all the results presented, silk cotton (Calotropis procera), chamomile (Matricaria chamomilla), winter\'s bark (Drimys winteri), bitter melon (Momordica charantia L.), corn silk (Zea mays), graviola (Annona muricata), purple trumpet tree (Tabebuia sp.), malva - folhas (Malva sylvestris) e unha de gato (Uncaria tomentosa) silk cotton (Calotropis procera), chamomile (Matricaria chamomilla), graviola (Annona muricata) and mallow-leaves (Malva sylvestris) were the most effective extracts reaching different cell types and present high selectivity indices. With the accomplishment of this work we can conclude that the natural extracts of plants presented antiproliferative activity in cancer lines and their phytochemicals can be used to study new herbal medicines. The next step, then, is to understand the molecular mechanisms where they act.

O câncer de mama é a neoplasia com maior mortalidade entre as mulheres. O emprego de agentes alquilantes no tratamento desta neoplasia pode ocasionar o surgimento de instabilidades genômicas. Tais instabilidades podem estar associadas ao desenvolvimento de neoplasias secundárias como, por exemplo, leucemias. A presente tese avaliou a instabilidade de microssatélites em amostras de sangue, sedimento urinário e plasma de pacientes portadoras de carcinoma mamário ao diagnóstico, 3 e 6 meses após o início do tratamento quimioterápico. Também foi avaliada a concentração do DNA plasmático livre como possível marcador tumoral junto aos marcadores séricos CEA e CA15.3, empregados no acompanhamento do câncer de mama. Foram avaliadas as regiões de microssatélites: Tp53-ALU, Tp53.PCR15.1, BAT 40, BAT26, FMR2 e APC. Entre as 40 pacientes incluídas no presente estudo 88,57% apresentaram instabilidade de microssatélites na fração mononuclear do sangue periférico, 85,8% nas amostras de sedimento urinário e 62,5% no DNA plasmático livre. Não houve concordância significativa entre as instabilidades encontradas nos três tipos de amostra. A concentração de DNA plasmático livre das pacientes quando comparada às doadoras sadias apresentou correlação estatisticamente significativa (p>0,0001), e em paciente em regimes neoadjuvantes que responderam objetivamente à quimioterapia (p=0,02) e não houve correlação com os marcadores séricos CEA e CA15.3. / Breast cancer has the major mortality in women among all kind of cancer. The use of alkylating agents at the treatment of this disease is associated with genomic instability. This instability could be associated with the development of secondary cancer, for example, leukemia. The present thesis evaluated microsatellite instability in blood, pellet cells urinary and plasma in patients with breast cancer at diagnosis, 3 and 6 months after the beginning of chemotherapy. There were evaluated also Free Plasmatic DNA concentration as a possible tumoral marker with the serum markers CEA and CA15.3 used in breast cancer follow up. The microsatellites regions assayed were: Tp53-ALU,Tp53.PCR15.1, BAT 40, BAT26, FMR2 e APC. Among the 40 patients included at the present study 88,57% showed microsallite instability in peripheral mononuclear blood cells, 85,8% in urinary pellet cells samples and 62,5% in Free Plasmatic DNA. There werent statistical significant relationship for the instability found at the three kind of samples assayed. The Free Plasmatic DNA concentration of the patients when compared with healthy donors, showed a statistical significant relationship (p<0,0001). And among patients in neoadjuvant chemotherapy regime who reacted positively by treatment (p=0,02). And there werent statistical significant relationship between Free Plasmatic DNA and serum markers CEA and CA15.3.

In order to gain insights into the underlying mechanisms, several methods including, flow cytometric, western blot and quantitative real-time PCR analyses were employed. AITC-induced cell growth inhibition in SW620 cells was mainly caused by G2/M arrest, which was accompanied by regulatory proteins modifications. Results of western blot and quantitative real-time PCR analysis showed clear downregulation of pivotal phosphatases Cdc25B and Cdc25C at both transcriptional and post-translational levels in AITC-treated cells. Subsequently, accumulation of inhibitory phosphorylation of Cdc2 on Thr14 and Tyr15 were resulted. Furthermore, an AITC induced apoptosis after prolonged exposure was observed. It was a caspase-mediated apoptosis as evidenced by the activation of initiator caspases (-8 and -9), effector caspases (-3 and -7) and cleavage of Poly (ADP-ribose) polymerase (PARP). Besides in vitro studies, the antitumor activity of AITC was further illustrated by a nude mice xenografts experiment. Treatment with 10 micromol AITC could effectively suppress the growth of SW620 xenografts in vivo. Taken together, our results suggest that AITC is an attractive candidate for future research in chemotherapy and chemoprevention. / Many epidemiological studies indicate that a high intake of cruciferous vegetables, such as cabbage, broccoli and Brussels sprouts, may reduce the risk of certain types of cancer. Glucosinolates in cruciferous vegetables and their digested products are suggested to play an important role in such chemoprevention. When plant tissue is physically damaged, glucosidic bonds are cleaved by endogenous myrosinase to produce various products. Among these products, isothiocyanates (ITCs) draw most of the attention because of their potent antitumor activities. But the molecular mechanism leading to such effects has not yet been defined. / The objective of this study was to investigate the chemotherapeutic potential of allyl isothiocyanate (AITC) towards human colorectal adenocarcinoma cells. Another commonly founded ITC, phenylethyl isothiocyanate (PEITC) was employed as a reference sample. The growth inhibitory effects of ITCs on different colorectal adenocarcinoma cells were investigated using in vitro cell models. Both AITC and PEITC were found to inhibit the growth and proliferation of Caco-2, COLO 201 and SW620 cells in a time- and dose-dependent manner. Based on sensitivity, the most vulnerable SW620 cells were chosen for further studies. In the following BrdU assay, IC50 values for 24-h AITC and PEITC treatments were determined to be 30.2 and 9.21 microM, respectively. At the same time, the effects of ITCs on human normal skin fibroblast Hs68 cells were also investigated. It was found that the survival of Hs68 cells was not affected by the treatments of AITC. However, the survival of Hs68 cells was greatly affected by PEITC-treatments in a dose- and time-dependent manner. / Lau, Wing Sze. / Adviser: Wong Yum Shing. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 115-128). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Absorption study showed that gossypetin was methoxylated and conjugated to form glucuronide during the first-pass metabolism after oral administration. Glucuronide conjugate was the major circulating form in the plasma. As determined by HPLC analysis, the total gossypetin concentration in the plasma was higher than the unchanged gossypetin indicating that most of gossypetin underwent first-pass metabolism. Moreover, urinary excretion was not a main elimination route. / Uses of foods and dietary supplements present a safe chemopreventive strategy. The application of phytochemicals for cancer prevention currently receives a great deal of attention. Flavonoids are known to be antiproliferative and may play an important role in the prevention of carcinogenesis. In addition to epidemiologic studies, basic science research to elucidate mechanisms and evaluate chemopreventive potential of phytochemicals is also necessary. In this study, gossypetin was found to have stronger antiproliferative activity when compared with quercetin, a well studied flavonoid, in human hepatocellular carcinoma (HepG2) cells and human breast carcinoma (MCF-7) cells. The results demonstrated that gossypetin induced growth inhibition in MCF-7 cell line by arresting cell cycle at G0/G1 phase. The inhibition of cell cycle progression was associated with the decrement of cyclin D1 expression, cdk6 kinase activity and phosphorylation of retinoblastoma protein (pRb). Although the cdk inhibitor p21 could not be detected, its upstream protein, p53 tumor suppressor protein, was activated by gossypetin in the MCF-7 cell line. Also, the proliferation of MCF-7 cells was suppressed through down-regulating the Erk1/2 pathway. / Ngai Lei-ka. / "August 2005." / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6156. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 222-250). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.