Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A pesquisa para o desenvolvimento de novas drogas quimioterápicas, tem se baseado nas propriedades dos produtos de origem natural. Estudos experimentais em animais indicam que o álcool perílico (AP), um monoterpeno originalmente isolado dos óleos essenciais de várias plantas é capaz de causar a regressão de diferentes tipos de tumores. O tratamento clássico preconizado para os astrocitomas anaplásicos e glioblastoma multiforme consiste de: ressecção cirúrgica, radioterapia e/ou quimioterapia e raramente apresentam efeito curativo. O presente trabalho teve como objetivo analisar o efeito do AP na proliferação, na alteração da morfologia, na síntese de proteínas e migração celular de diferentes linhagens de glioblastoma murino e humano. Foram utilizados modelos in vitro de cultivo de células e ensaios in vivo de migração celular. O tratamento in vitro com o AP nas concentrações v/v de 0,003%, 0,02%, 0,03%, 0,3%, 3% e 30% nas linhagens de glioblastoma C6 de murinos e linhagens A172 e U87MG de glioblastoma humano, mostrou que mesmo nas concentrações (v/v) mais baixas (0,03% e 0,3%) o AP promove a inibição da proliferação celular e da síntese de proteínas. O tratamento in vitro com o AP a 0,3% v/v causou após 15 minutos perda da permeabilidade celular e mais tardiamente, 50 minutos, alterações acentuadas na citoarquitetura das linhagens C6, U87MG e A172. Nos ensaios in vivo com ovos embrionados, o tratamento com o AP nas concentrações v/v 0,3% e 0,03% causou efeito inibitório na migração celular da linhagem C6. Os resultados sugerem uma eficácia quimioterápica do AP na citotoxidade e na inibição da migração celular de linhagens de glioblastoma murino e humano. / The search for new chemotherapeutic drugs has increased, especially for those that have a natural origin. Perillyl alcohol (POH), is a naturally occurring monoterpene, found in the essential oils of citrus fruits and other plants, with pronounced chemotherapeutic activity and minimal toxicity in preclinical studies. Standard treatment of anaplastic gliomas and glioblastoma multiforme consisting of surgical resection, radiation therapy and/or chemotherapy is rarely curative. This work aimed to evaluate in vitro and in vivo effects of POH treatment, cell proliferation, changes in morphology, protein synthesis, and migration of distinct lineage of glioblastoma cells. It was chosen in vitro culture systems and in vivo assays for assessing cellular migration. In vitro treatment of POH at concentrations of (v/v) 0.003%, 0.02%, 0.03%, 0.3%, 3% and 30%, consistently inhibited proliferation of murine C6 and human A172 and U87MG of glioblastoma cells. In vitro treatment of POH at low concentrations 0.03% v/v and 0.3% v/v also produced marked changes in cell morphology and inhibited protein synthesis. Likewise in vitro assays with 0.3% v/v POH treatment for 15 minutes, initially caused marked alteration in membrane permeability and later (50 minutes) drastic changes in the cytoarchitecture of C6, U87MG and A172 cells. Furthermore, previous in vitro treatment of glioblastoma cells with 0.3% v/v and 0.03% v/v POH showed inhibition of cell migration and anti-metastatic activity in the in vivo model of the chick embryo with C6 cell line. Such results indicate the chemotherapeutic action of POH by promoting cytotoxicity and arresting migration of murine and human glioblastoma cell lines

New Zealand has the second highest incidence of melanoma skin cancer in the world. Chemotherapy is the standard treatment for melanoma derived tumours which have undergone metastasis and current therapies have limited benefit. There is a great need for new therapies and to increase the efficacy of current therapies. Temozolomide (TMZ) is a chemotherapy agent effective in the treatment of both metastatic melanoma and glioblastoma (brain cancer), although TMZ resistance has been observed in many tumours. The activity of the DNA repair enzyme O6 methyl-guanine methyltransferase (MGMT) is thought to be largely responsible for TMZ resistance. MGMT protects the cell from the effects of TMZ by removing cytotoxic lesions placed on the DNA. Mechanisms of regulation of MGMT expression remain unclear in melanoma. DNA methylation at the MGMT promoter has been linked to MGMT silencing in some cancers and has been associated with specific chromatin modifications. The present study was aimed at investigating the promoter methylation status of MGMT in primary melanoma cell lines using a new technique named methyl DNA immuno-precipitation (MeDIP). Next, the chromatin immuno-precipitation (ChIP) method was used to examine post translational modifications on the surrounding chromatin. The data obtained was correlated with both MGMT transcription levels and TMZ sensitivity. The promoter methylation status of MGMT has been used to predict the clinical responsiveness of glioblastoma patients to TMZ. Establishing the regulatory mechanisms of MGMT expression in melanoma patients would validate a means to predict clinical responsiveness to TMZ. Furthermore, establishing mechanisms of MGMT silencing may provide the basis for future clinical trials of novel therapies for melanoma and glioblastoma.