Le chloroacétaldéhyde (CAA), un des principaux produits du métabolisme hépatique de l’ifosfamide (IFO), est considéré comme responsable de la néphrotoxicité de ce médicament. Les mécanismes exacts de cette néphrotoxicité ne sont pas complètement élucidés. Dans la première partie de cette étude, nous avons essayé de préciser les mécanismes physiopathologiques de la toxicité du CAA sur un modèle de tranches de cortex rénal de rat, puis, dans la deuxième partie, nous avons recherché un effet anticancéreux éventuel du CAA sur des cellules de cancer du sein humain (MCF-7). La néphrotoxicité du CAA, utilisé à des concentrations proches de celles mesurées chez les patients traités par l’IFO, soit 0 - 75 µM, s’est manifestée par une chute d’ATP et du glutathion ainsi que par une inhibition du métabolisme du lactate. Certaines enzymes de la néoglucogenèse, notamment la glyceraldéhyde 3-phosphate déshydrogénase, ont été inhibées par le CAA. Le complexe I de la chaîne respiratoire mitochondriale ainsi que l’oxydation du lactate ont été également inhibées par le toxique. D’autre part, le CAA (10 et 25 µM) a inhibé la prolifération des cellules MCF-7 sans que cette inhibition soit accompagnée d’une chute d’ATP cellulaire. Le transport cellulaire et le métabolisme du glucose ainsi que certaines enzymes de la glycolyse ont été également inhibés par le CAA. Parmi celles-ci, l’hexokinase semble être l’enzyme qui catalyse l’étape limitante de la voie de la glycolyse. En conclusion, le CAA est bien impliqué dans les mécanismes de la néphrotoxicité de l’IFO, mais de plus, il pourrait, via l’inhibition de la glycolyse, contribuer à l’effet thérapeutique de l’IFO. / Chloroacetaldehyde (CAA), one of the main products of ifosfamide (IFO) hepatic metabolism, is considered as responsible of IFO nephrotoxicity. The mechanisms of this nephrotoxicity are not completely known. In the first part of this study, we tried to clarify the pathophysiological mechanisms of CAA toxicity using precision-cut rat renal cortical slices, then, in the second part, we looked for a possible anticancerous effect of CAA on human breast cancer cells (MCF-7). Using clinically-relevant concentrations (0-75 µM), CAA nephrotoxicity was demonstrated by the depletion of ATP and glutathione and by the inhibition of lactate metabolism. Some of the gluconeogenic enzymes, mainly glyceraldehyde 3-phosphate dehydrogenase, were inhibited by CAA. The complex I of the mitochondrial respiratory chain as well as lactate oxidation were also inhibited by CAA. On the other hand, CAA (10 and 25 µM) inhibited MCF-7 cell proliferation which was not accompanied by cellular ATP depletion. Glucose transport and metabolism as well as some of the glycolytic enzymes were also inhibited by CAA. Hexokinase seems to be the rate-limiting enzyme of glycolysis. In conclusion, CAA is implied in the mechanisms of IFO-induced nephrotoxicity; furthermore, it could, via the inhibition of the glycolytic pathway, contribute to the therapeutic effect of IFO.

INTRODUÇÃO: A prolactina é um hormônio polipeptídico que possui reconhecida ação sistêmica, principalmente no sistema reprodutor. O papel desse hormônio no desenvolvimento e na extensão do câncer da mama ainda é muito debatido. A progressão do câncer de mama em grande parte depende do movimento celular e da capacidade da célula em remodelar seu citoesqueleto de actina. Nesse processo, proteínas envolvidas na migração celular, como moesina, FAK e c-Src, são influenciadas por vários hormônios, incluindo a prolactina. O presente estudo teve por objetivo avaliar os efeitos da PRL na migração de células T47D, MCF-7 e ZR75-1 de câncer de mama, bem como os mecanismos envolvidos. MÉTODOS: As células foram cultivadas em placas de cultura com meio suplementado e divididas em oito grupos diferentes de tratamento: Grupo I (veículo); Grupo II (PRL na concentração de 25 ng/mL); Grupo III (PRL na concentração de 50 ng/mL), Grupo IV (PRL na concentração de 100 ng / mL), Grupo V (RNAi + veículo); Grupo VI (RNAi + PRL na concentração de 25 ng/mL); Grupo VII (RNAi + PRL na concentração de 50 ng/mL) e Grupo VIII (RNAi + PRL na concentração de 100 ng / mL). Nos Grupos de I a IV, a reorganização da actina do citoesqueleto foi analisada por imunofluorescência após 30 minutos do tratamento. Em todos os grupos estudados foram realizadas análise da migração horizontal com auxílio de microscopia de luz e avaliadas as expressões de Moesina, p-Moesina, FAK, p-FAK, c-Src e p-c-Src por Western Blot após 48 horas do tratamento. RESULTADOS: As células de câncer de mama expostas à prolactina apresentaram um aumento da expressão de Moesina, p-Moesina, FAK, p-FAK, c-Src e p-c-Src. Essas alterações moleculares estão associadas à reorganização da actina do citoesqueleto e ao aumento da mobilidade das células. CONCLUSÕES: Nossos dados sugerem que a prolactina aumenta a migração das células T47D, MFC-7 e ZR75-1 de câncer de mama e remodela a actina do citoesqueleto pela via de sinalização intracelular das proteínas c-Src, FAK e moesina / INTRODUCTION: Prolactin is a polypeptide hormone with a recognized systemic action mainly on reproductive physiology. The role of this hormone on breast cancer development and progression has been debated a lot yet. Breast cancer invasion largely depends on cell movement and on the ability to remodel the actin cytoskeleton. In this process, proteins involved in cell migration, such as moesin, FAK and c-Src, are influenced by a large number of hormones, such as prolactin. The present study was aimed for evaluating the effects of PRL on migration of T47D, MCF-7 and ZR75-1 breast cancer cells as well as the molecular mechanisms in this process. METHODS: The cells were cultured in dishes with supplemented medium and were divided in eight different assays: Group I (control); Group II (25ng/ml of prolactin); Group III (50ng/ml of prolactin); Group IV (100ng/ml of prolactin); Group V (RNAi + control); Group VI (RNAi + 25ng/ml of prolactin); Group VII (RNAi + 50ng/ml of prolactin); Group VIII (RNAi + 100ng/ml of prolactin). In Groups I to IV, the actin cytoskeletal reorganization was analyzed by immunofluorescence 30 minutes after the treatment. In all groups, were performed the horizontal migration analysis with light microscopy and evaluated the expression of moesin, p-moesin, FAK, p-FAK, c-Src and p-c-Src by Western blot after 48 hours of treatment. RESULTS: Breast cancer cells exposed to prolactin display an elevated moesin, p-moesin, FAK, p-FAK, c-Src and p-c-Src expression. These molecular changes are associated with the reorganization of actin cytoskeleton and increased mobility of cells. CONCLUSION: Our data suggest that prolactin enhances the migration of T47D, MFC-7 and ZR75-1 breast cancer cells through the actin cytoskeleton remodeling by intracellular signaling pathway of c-Src, FAK and moesin proteins

Thesis (MSc (Radiography))--Cape Peninsula University of Technology, 2018 / Background: Breast cancer is one of the most commonly diagnosed among woman in South Africa, and a more resilient effort should be focused on treatment improvements. Worldwide, proton therapy is increasingly used as a radiation treatment alternative to photon therapy for breast cancer, mostly to decrease the risk for radiation-induced cardiovascular toxicity. This in vitro study aims to determine a better understanding of the radiosensitivity of both tumour and normal breast cell lines to clinical proton irradiation. In addition, we propose to investigate whether the increase in linear energy transfer (LET) towards the distal part of the proton beam results in an increase in relative biological effectiveness (RBE) for both cell lines. Methods: Malignant (MCF-7) and non-malignant (MCF-10A) breast cells were irradiated at different water equivalent depths in a 200 MeV proton beam at NRF iThemba LABS using a custom-made Perspex phantom: the entrance plateau, 3 points on the Bragg peak, the D80% and the D40%. A cytokinesis-block Micronucleus (CBMN) assay was performed and Micronuclei (MNi) were manually counted in binucleated cells (BNCs) using fluorescent microscopy. Reference dosimetry was carried out with a Markus chamber and irradiations were performed with a clinical proton beam generated at NRF iThemba LABS that was degraded to a R50 (half-value depths) range of 120 mm, with a field size of 10 cm x 10 cm and a 50 mm SOBP. The phantom could be adjusted to accommodate different perspex plates depending on the depth required within the proton beam. Cells were then exposed to 0.5, 1.0, 2.0, 3.0 and 4.0 Gy doses for each cell line independently and for each dose point. Results and Discussion: For the CBMN results, a program was developed on Matlab platform to calculate the 95% confidence ellipse on the co-variance parameters α and β. These values were determined by fitting the linear quadratic dose response curve to the average number of radiation induced MNi per 1000 BN cells. The ellipse region around a coordinate (the average MN frequency) for both MCF-7 and MCF-10A cells at the plateau region was defined by the mean estimate of the α-value and the β-value that were plotted on the X-axis and Y-axis respectively. The ratio of the two parameters, α/β, is a measure of the impact of fractionation to determine the biological effective dose. In fractionated proton therapy, the MCF10A cells will repair less between two fractions compared to the MCF7 cells. This is not an indication of therapeutic gain from a fractioned treatment protocol. For this reason, the hypofractionated stereotactic treatment protocols that can be applied with protons could be to the befit of the breast cancer patient. The above argument is based only on the radiosensitivity of the two cell lines exposed in the plateau region. Further analysis of the 95% confidence ellipse of both cell lines also showed a clear increase of the alpha value toward the distal portion of the beam and indicates an increase in energy transfer in this region. The gradual increase in α and β parameters with depth for protons for both cells is of clinical importance, since it implicates a non-homogeneous dose within the targeted area and an unwanted high dose behind the targeted area. Distal energy modulation could be investigated especially with larger breast tumours. RBE was calculated as the ratio of the dose at the different positions to the dose at the entrance plateau position (reference) to obtain an equal level of biological effect. A statistically significant difference in radiosensitivity could be observed between malignant and non-malignant cells at all positions (p<0.05). The variation in RBE was between 0.99 to 1.99 and 0.92 to 1.6 for the MCF-7 and MCF10A cell respectively. Conclusions: There is a variation in RBE along the depth-dose profile of a clinical proton beam. In addition, there is difference in radiosensitivity between the cancerous cells and the normal breast cells. While this study highlights a variation in sensitivity between cells it could be used by the modelling community to further develop biologically motivated treatment planning for proton therapy.

Mitochondria are the main sites for adenosine triphosphate (ATP) generation within most cells. Structural and functional alterations of mitochondria due to genetic abnormalities of mitochondria can cause respiratory chain dysfunction. In this study, the important role of mitochondria in energy metabolism was determined by comparing the effect of mitochondrial DNA (mtDNA) mutations on growth patterns and oxidative phosphorylation (OXPHOS) enzyme activities of six isolated clones (B5, B12, D4, D9, E1 and E8); as well as the effect of ATP supplement to culture using the slowest growing clone. The isolated clones had shown distinct growth pattern and morphology. The difference in proliferation rates among the clones was ascertained by the doubling times (B5=26.4h. B12=43.2h. D4=25.7h. D9=33.6h. E1=26.9h and E8=28.8h). The clone's slow growth rate was likely the result of mitochondrial mutations in the 16S rRNA gene, ND1, ND4, ND6 and COX III. Five heteroplasmic mutations were found in clone B12 (G2480T, C2513G, A2520T, C9527T and C14263G), one heteroplasmic mutation in clone D9 (A4137G) and one homoplasmic mutation in clone D4 (C11496). The mutations in clone B12 appeared to be deleterious to the cell by disrupting mitochondrial OXPHOS activities and reducing energy output. Additionally, extracellular ATP supplement to OXPHOS deficient clone B12 facilitated cell growth and enhances the gene expression. Increased expression of mtDNA-encoded respiratory chain complexes observed in clone B12 compared to clone D4 may reflect mitochondrial genomic adaptation to perturbations in cellular energy requirements. The stimulation of mitochondrial biogenesis may be a cellular response in compensation for defects in OXPHOS associated with mtDNA mutations. My data support the hypothesis that the variability in functional manifestations of mtDNA is attributed to the nature of the mutation, number of mutation and the gene specifically affected. These results will help to further our understanding of the relationship between mitochondrial mutation and cellular function.

Mastitis is often bacterial in origin. Lipoteichoic acid (LTA) and lipopolysaccharide (LPS), endotoxins from gram-positive and gram-negative bacteria, respectively, are potent inducers of mammary gland inflammation. Inflammation can alter expression of transporters responsible for transport of substrates important in synthesis of milk constituents and cellular metabolic energy. Since, gram-positive and gram-negative bacterial infections cause a different clinical course of mastitis, I investigated whether LTA and LPS differentially alter proton-coupled (MCT1) and sodium-coupled monocarboxylate transporter (SMCT1, SMCT2) expression and functional outcomes of altered expression. Human mammary epithelial cells (MCF-12A) were incubated with 1 microgram/mL LPS or LTA for 6, 12 and 24 hours and mRNA expression of TNF-alpha, IL-1β, IL-6, MCT1, SMCT1, and SMCT2 were measured using Quantitative RT-PCR. LPS decreased SMCT1, but increased SMCT2 expression after 6 h, while LTA increased MCT1 expression at 6 h, followed by gradual decrease in expression until 24 h. To know whether such differential changes in transporter expression by LPS and LTA could cause changes in cellular energy production, I quantified creatine (Cr) and high-energy phosphate substrates (CrP, ATP, ADP, AMP) and oxygen consumption rates using HPLC and Hansatech oxygen electrode, respectively. At 12 h, LPS increased concentrations of Cr, CrP, ATP and ADP, whereas LTA caused changes in CrP and ADP concentrations relative to control. Both LPS and LTA decreased oxygen consumption rates after 12 h. Furthermore, to know whether changes in transporter expression lead to differences in substrate availability, I performed uptake studies for carnitine using radiolabelled tritium L-carnitine. LPS and LTA challenge did not affect the affinity, but caused a 2-3-fold increase in maximal activity (Vmax) of carnitine transport. Although increases in Vmax were not significant, the increase in Vmax after 12 h exposure by LPS and LTA corresponds to changes in mRNA expression of the OCTN2 transporter (previously reported in the laboratory). In conclusion, LPS and LTA differentially alter mRNA expression of transporters, which leads to changes in cellular energy levels and oxygen consumption rates and possibly to changes in the functional activity of transporters. Whether such differences contribute to the different clinical course of mastitis warrants further investigation.

No description available.

Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2017-07-25T18:53:17Z No. of bitstreams: 1 PRISCYLLA_ANDRADE_VOLKART_DIS.pdf: 1703523 bytes, checksum: 625ed4371e92d211496ba44a5d264d21 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-26T14:20:44Z (GMT) No. of bitstreams: 1 PRISCYLLA_ANDRADE_VOLKART_DIS.pdf: 1703523 bytes, checksum: 625ed4371e92d211496ba44a5d264d21 (MD5) / Made available in DSpace on 2017-07-26T14:27:43Z (GMT). No. of bitstreams: 1 PRISCYLLA_ANDRADE_VOLKART_DIS.pdf: 1703523 bytes, checksum: 625ed4371e92d211496ba44a5d264d21 (MD5) Previous issue date: 2017-03-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The redox-active chemical properties of trace element copper make it an essential cofactor for several cellular mechanisms, as for ROS production. Polyphenols have been used in the pro-oxidant mechanism of action of interaction with endogenous Cu (II) ions for the production of reactive oxygen species in excess as a treatment for malignancies, leading to apoptosis. This work studied Cu (II) ions in the complex formation mechanism with Resveratrol in MCF-7 cells model. We analyzed the selectivity of Resveratrol in relation to the cupric metal ion using HPLC (High-Performance Liquid Chromatography) and the formation of the compound Resveratrol-Copper through UV-VIS (Ultra-Violet Visible Spectrophotometry). We analyzed the cellular morphology and location of the metal ion by MET-EDS (Electronic Transmission microscopy with Dispersive X-ray Spectroscopy). Cell death by apoptosis and quantification of ROS in said cell line with copper enrichment and treated with Resveratrol was made by flow cytometry. The results show the selectivity of the polyphenol compound by copper ion as well as the formation of the complex Resveratrol-Copper in extracellular conditions, however even with verification of endogenous copper accumulation in physiological conditions in vitro, the formation of that complex did not occur because there was no production of ROS and therefore, no cell death. In short, our research reveals that for in vitro conditions for the MCF-7 line, there's no Resveratrol-Copper complex formation as observed in sub-lethal quantities of chemically enriched cells with CuSO4 and treated with Resveratrol. / As propriedades qu?micas redox-ativas do oligoelemento cobre o tornam cofator essencial para diversos mecanismos celulares como o de produ??o de ROS. Polifen?is v?m sendo utilizados no mecanismo de a??o pr?-oxidante de intera??o com ?ons Cu (II) end?geno para a produ??o dessas esp?cies oxig?nio reativas em excesso como tratamento de malignidades, levando a apoptose. O presente trabalho estudou os ?ons Cu (II) no mecanismo de forma??o do complexo com Resveratrol em modelo de c?lulas MCF-7. Analisamos a seletividade do Resveratrol frente ao ?on met?lico c?prico utilizando CLAE (Cromatografia L?quida de Alta Efici?ncia) e verificou-se a forma??o do complexo Resveratrol-Cobre por meio de UV-VIS (Espectrofotometria de Ultra-Violeta Vis?vel). Analisou-se a morfologia celular e localiza??o do ?on met?lico por MET-EDS (Microscopia de Transmiss?o Eletr?nica com Espectroscopia Dispersiva de Raios-X). Morte celular por apoptose e quantifica??o de ROS na linhagem enriquecida com cobre e tratadas com Resveratrol foi feita por Citometria de Fluxo. Os resultados mostram a seletividade do composto polifen?lico pelo ?on cobre bem como a forma??o do complexo Resveratrol-Cobre em condi??es extracelulares, por?m mesmo com a verifica??o de ac?mulo de cobre end?geno, em condi??es fisiol?gicas in vitro n?o foi constatada a forma??o do referido, pois n?o houve forma??o de ROS e morte celular conseguinte. Em suma, Nossa pesquisa revela que em condi??es in vitro para a linhagem MCF-7, n?o h? forma??o de complexo Resveratrol-Cobre como observado quimicamente em quantidades sub-letais de c?lulas enriquecidas com CuSO4 e tratadas com Resveratrol.

After menopause, a woman's production of 17-estradiol, the predominant female sex hormone, declines. This change is associated with increased risk of osteoporosis/osteopenia and atraumatic bone fracture, cardiovascular disease, and breast and ovarian cancers. Phytoestrogens are non-steroidal compounds isolated from plants that have antagonistic, weak agonistic, or super-agonistic estrogenic effects in mammalian tissues; they have emerged as a potential therapeutic to alleviate post-menopausal symptoms. While some epidemiological evidence indicates that dietary consumption of phytoestrogens can alleviate post-menopausal health risks, other research suggests that phytoestrogens may not be completely safe. The research presented in this thesis indicates that a high concentration and sustained dose of phytoestrogens may be necessary to achieve antiestrogenic effects. MCF-7 cells, an estrogen-sensitive breast adenocarcinoma cell line, were used as a model system, and proliferating cell nuclear antigen (PCNA) was used as a marker of cell proliferation. Immunoblotting shows that genistein, a commercially purified phytoestrogen, promotes cell proliferation when administered for 24 hours, but may reduce proliferation when cells were treated for 48 hours. Genistein and estrogen have an additive effect on cells that were treated simultaneously with both hormones for 24 hours. In contrast, Promensilâ„¢, an over-the-counter phytoestrogen dietary supplement, was able to abolish expression of PCNA after 48 hours, and at high concentrations prevented estrogen-induced upregulation of PCNA after 48 hours. The clinical significance of these findings is that phytoestrogens may reduce the risk of breast cancer, but only after sustained high doses, which may be difficult if patient non-compliance is at issue. Additionally, because cell proliferation and not cell survival was investigated, we cannot say whether phytoestrogens are cytotoxic to breast cancer cells, only that they reduce proliferation.

Thesis (M.Sc. (Biochemistry)) --University of Limpopo, 2017 / Cancer is a broad group of various diseases characterised by unregulated cell proliferation which leads to the formation of tumours (Vickers, 2004). Some tumours remain confined to their site of origin while some gain the ability to spread to other parts of the body, a process known as metastasis (Weiss, 1990). The burden of cancer continues to rise, due to inefficient prevention strategies and serious side effects, as well as the cost of cancer regimens (Sondhi et al., 2010). Medicinal plants represent a reservoir of bioactive compounds that can be useful in the management of cancer with less or no side effects (Wong et al., 2012). The aim of this study was to investigate the anti-cancer effects of M. balsamina leaf extract in breast MCF-7 cancer cells. In this study, M. balsamina leaves powder was extracted using acetone. The biological effect of the extract was assessed on the viability of MCF-7 cells using the MTT assay. The extract’s ability to induce apoptosis was assessed using the Hoechst/propidium iodide dual staining method. Its anti-metastatic potential was investigated by determining its effect on MCF-7 cell migration, attachment and invasion using wound healing, adhesion, invasion assay, respectively. The human apoptosis antibody and human angiogenesis antibody array kits were used to determine the effect of the extract on the expression levels of proteins involved in apoptosis and metastasis, respectively. Treatment of MCF-7 cells with different concentrations of the extract showed a significant decrease in cell viability after 48 h incubation at 10 - 20 µg/ml. The decrease in cell viability was associated with the induction of apoptosis as seen by nuclear condensation and loss of membrane permeability in cells treated with the extract. Inhibition of migration, adhesion and invasiveness of the MCF-7 cells was seen in the treated cells. The extract also modulated proteins implicated in cell apoptosis, adhesion, migration and invasion such as Bcl-2 family of proteins, IGFBP, uPA, MMPs. In conclusion, based on the results, the extract show pro-apoptotic and anti-metastasis potential. Thus M. balsamina can be considered as a potential source of compounds with anti-cancer activity

Steroid receptor coactivators modulate the final outcome of hormone induced gene transcription by steroid receptors. E6-associated protein (E6-AP), an E3 ubiquitin ligase, acts as a coactivator of steroid receptors, including estrogen receptor (ER). In this study, we elucidated the contribution of E6-AP to ER-dependent gene transcription in breast cancer cells. siRNA-mediated knockdown of E6-AP abrogates transcription of classic ER target genes, GREB1 and pS2, suggesting that E6-AP is essential for normal transactivation function of ER. In order to understand the global influence of E6-AP in ER-dependent gene transcription, we used gene expression microarrays under E6-AP knockdown conditions to identify ER target genes which are regulated by E6-AP. Our microarray analysis revealed 455 genes which are differentially regulated by E6-AP. Pathway analysis revealed that E6-AP regulated genes were involved in cell cycle. Cell cycle profiling at various time points of estrogen treatment reveals that under E6-AP knockdown conditions, breast cancer cells progress slowly through S phase and eventually fail to proliferate. Knockdown of E6-AP has no effect on ovarian and uterine cells, suggesting that E6-AP has cell specific roles. Our analysis suggests that knockdown of E6-AP reduces the levels of early (C-Myc and Cyclin-D1), mid (E2F1, E2F2 and E2F7) and late (BUB1, BUBR1, MAD2, NDC80, NUF2 and CASC5) estrogen-dependent cell cycle genes. Overall our data indicate that E6-AP is a major regulator of cell cycle in breast cancer cells. E6-AP also acts as a coactivator for androgen receptor (AR) and we studied the role of E6-AP in prostate gland development. We report the generation of transgenic mice which specifically over expresses E6-AP in the prostate gland. Prostate glands in these mice are larger when compared with its wild-type litter mates, corroborating our observations that knockout of E6-AP in mice leads to impaired prostate gland development. E6-AP transgenic mice also develop prostatic intra epithelial neoplasia after 18 months of age. In addition to these observations, we also show that over expression of E6-AP in the prostate gland leads to increased Akt signaling. In order to understand the mechanism by which E6-AP regulates prostate gland growth, we generated LNCaP cells that stably overexpress E6-AP protein. Data from these cell lines show that the levels of phosphatidylinositol 3-kinase, total Akt, phosphorylated Akt (active Akt) and its down-stream target protein, GSKβ are elevated, suggesting that E6-AP regulates the PI3K-Akt signaling pathway. We further show that E6-AP modulates PI3K-Akt signaling by regulating the protein levels of RhoA, a small GTPase, which is a negative regulator of the Akt signaling pathway. In addition, we show that stable overexpression of E6-AP in prostate cancer cells results in increased proliferation. Overall our data suggests that E6-AP regulates the PI3K-Akt pathway in prostate cells which results in increased prostate cell growth, proliferation and tumorigenesis.