Síntese, avaliação biológica e modelagem molecular de potenciais antitumorais análogos da sanguinarina planejados por simplificação molecular / Synthesis, biological evaluation and molecular modeling of potential antitumors analogues from sanguinarine designed by molecular simplification

A sanguinarina é um alcaloide capaz de inibir Bcl-xL, uma proteína antiapoptótica que se encontra superexpressa em linhagens tumorais e que está frequentemente relacionada à resistência destas frente a quimioterápicos antineoplásicos. No intuito de identificar potenciais agentes antitumorais, o objetivo deste trabalho foi sintetizar três séries de análogos da sanguinarina planejados por simplificação molecular e avaliar sua atividade biológica. Dez N-benzil-naftil-aminas (3a-e; 4a-e) e dez arilisoquinolinas (6a-e; 7a-e) foram sintetizadas em duas a três etapas reacionais, utilizando-se métodos de aminação redutiva e acoplamento de Suzuki. Insucesso na etapa de reação de Heck impossibilitou a síntese da terceira série, benzofenantridínica, apesar de testadas diversas condições reacionais. Avaliação da citotoxicidade em linhagens de glioblastoma U87MG revelou que a série N-benzilnaftil-amina apresenta melhor atividade quando comparada às aril-isoquinolinas, sendo para ambas, observada atividade superior à temozolamida, principal fármaco para o tratamento de glioblastoma. Estudos em linhagem não tumorigênica MRC-5 demonstraram que os análogos foram significativamente superiores à sanguinarina em relação à seletividade. Os compostos mais mais promissores, 4a e 6e, induziram morte celular por apoptose e causaram despolarização da membrana mitocondrial, indicando morte apoptótica pela via extrínseca. Ademais, 4a interrompeu o ciclo interrompeu o ciclo celular na fase G2/M, indicando que o mesmo seria um agente ciclo celular específico. Simulações de dinâmica molecular sugerem que os compostos interagem com a proteína Bcl-xL principalmente por interações hidrofóbicas, e que o composto 4a apresentaria afinidade com o alvo semelhante à sanguinarina, embora esta tenha apresentado atividade superior em células U87. Perspectivas incluem estudos das vias de indução de morte celular, além da expansão do painel de células. Conclui-se, portanto, que os análogos da sanguinarina representam um arcabouço a ser explorado pelos químicos medicinais no desenvolvimento de potenciais antineoplásico

Sanguinarine is an alkaloid able to inhibit Bcl-xL, an antiapoptotic protein which is overexpressed in tumor cells and related to their resistance against antineoplastic chemotherapy. Regarding to develop potential antitumor agents, the aim of this work was the synthesis of three series of sanguinarine analogues designed by molecular simplification and their biological evaluation. Ten N-benzyl-naphtyl-amines (3a-e; 4ae) and ten aryl-isoquinolines (6a-e; 7a-e) were synthesized in two or three reaction steps through reductive amination and Suzuki coupling. Failure about Heck-type reaction had impaired the synthesis of the thirth series, benzophenanthridine, although several conditions were tested. Cytotoxicity evaluation against U87MG glioblastoma cell line showed that N-benzyl-naphtyl-amines are more active than aryl-isoquinolines and both series were superior to temozolamide, the main drug for glioblastoma treatment. Tests against non-tumorigenic cell MRC-5 indicated that the analogues were significantly superior to sanguinarine regarding selectivity. The most promising compounds, 4a e 6e, induced cell death by apoptosis and mitochondrial membrane depolarization, indicating apoptotic death by extrinsic pathway. 4a provide cell cycle arrest at G2/M phase, suggesting that it is a specific cell cycle agent. Molecular dynamics suggested that compounds interact with Bcl-xL mainly by hydrophobic interactions and 4a has affinity to the protein like sanguinarine, although the last showed superior activity against U87 cells. Perspectives include mechanistics studies about cell death pathway and expanding cell panel. In conclusion, sanguinarine anlogues represent a scaffold to be explored by medicinal chemists to the development of potential antitumor agent

Oncogene-induced transcriptional patterns in established cell lines as a model for in vitro analysis of tumor biology

Established cell lines have long been used for in vitro studies of tumor biology, enabling investigators to control growth conditions and to draw important conclusions about the oncogenic microenvironment. However, gene expression behavior in cultured cells may not always reflect the actual in vivo scenario, and analysis derived from such experiments should take into consideration the existing differences between the two environments. We used suppression subtractive hybridization to study transcriptional changes elicited after oncogene transformation and cell line establishment. We found that transcriptional changes elicited in cultured cell lines are in fact representative of late events, and they do not occur early after oncogene transfection or activation. We also determined that a fraction of the transcriptional changes is oncogene specific, whereas other changes are shared between two or more different oncogenes.

Turner's syndrome variant with three cell line mosaicism and ring X chromosome [45, X /46,X r [X] [p21 q25] /46,Xx] in a Saudi patient

A case of Turner's Syndrome with three cell line mosaicism associated with ring X Chromosome, which is an extremely rare condition. Perhaps this is the first case report, with such chromosomal abnormality, from Saudi Arabia. The phenotypical changes are comparable with classical Turner's Syndrome of 45, X complement. The other findings are also discussed

Susceptibility of cell lines to avian viruses

The susceptibility of the five cell lines - IB-RS-2, RK-13, Vero, BHK-21, CER - to reovirus S1133 and infectious bursal disease virus (IBDV vaccine GBV-8 strain) was studied to better define satisfactory and sensitive cell culture systems. Cultures were compared for presence of CPE, virus titers and detection of viral RNA were detected in CER and BHK-21 cells after retrovirus inoculation and in RK-13 cell line after IBDV inoculation and with high virus titers. Virus replication by production of low virus titers occurred in IB-RS-2 and Vero cells with reovirus and in BHK-21 cell line with IBDV