Biologia 12 Ficha de Leitura nº Data: Unidade de Ensino: Conteúdo/assunto: Título: Fonte: Pesquisador:

Biologia 12

Ficha de Leitura nº 9 Data:07/06/11

Unidade de Ensino: Imunidade e controlo de doenças

Conteúdo/assunto: Utilização de proteínas na dilatação ou constrição de vasos sanguíneos

Título: Scientists Unlock Potential of Frog Skin to Treat Cancer

Resumo: Uma equipa de investigadores liderada pelo Professor Chris Shaw, descobriu proteínas na pele de sapos e rãs que têm a propriedade de estimular (alargar e multiplicar) ou comprimir os vasos sanguíneos presentes no nosso corpo.

Esta descoberta pode ser utilizada no tratamento de cancros, uma vez que as células cancerosas ao se desenvolverem necessitam de sangue que contenha oxigénio e nutrientes e sem estes vasos, o cancro pode abrandar ou até cessar o seu crescimento.

Fonte: http://www.sciencedaily.com/releases/2011/06/110606181137.htm (cons:07/06/2011)

Pesquisador: David Alecrim

Scientists Unlock Potential of Frog Skin to Treat Cancer

The award-winning research, led by Professor Chris Shaw at Queen's School of Pharmacy, has identified two proteins, or 'peptides', which can be used in a controlled and targeted way to regulate 'angiogenesis' -- the process by which blood vessels grow in the body. The discovery holds the potential to develop new treatments for more than seventy major diseases and conditions that affect more than one billion people worldwide.

The proteins are found in secretions on the skins of the Waxy Monkey Frog and the Giant Firebellied Toad. Scientists capture the frogs and gently extract the secretions, before releasing them back in to the wild. The frogs are not harmed in any way during this process.

Professor Shaw said: "The proteins that we have discovered have the ability to either stimulate or inhibit the growth of blood vessels. By 'switching off' angiogenesis and inhibiting blood vessel growth, a protein from the Waxy Monkey Frog has the potential to kill cancer tumours. Most cancer tumours can only grow to a certain size before they need blood vessels to grow into the tumour to supply it with vital oxygen and nutrients. Stopping the blood vessels from growing will make the tumour less likely to spread and may eventually kill it. This has the potential to transform cancer from a terminal illness into a chronic condition.

"On the other hand, a protein from the Giant Firebellied Toad has been found to 'switch on' angiogenesis and stimulate blood vessel growth. This has the potential to treat an array of diseases and conditions that require blood vessels to repair quickly, such as wound healing, organ transplants, diabetic ulcers, and damage caused by strokes or heart conditions."

Explaining how his research team looks to the natural world to solve problems where other methods of drug discovery have failed, Professor Shaw said: "Because of its huge potential, angiogenesis has been a prime target for drugs development research over the past forty years. But despite an investment of around $4-5 billion by scientists and drugs companies around the world, they have yet to develop a drug that can effectively target, control and regulate the growth of blood vessels.

"The aim of our work at Queen's is to unlock the potential of the natural world -- in this case the secretions found on frog and toad skins -- to alleviate human suffering. We are absolutely convinced that the natural world holds the solutions to many of our problems, we just need to pose the right questions to find them.

"It would be a great shame to have something in nature that is potentially the wonder drug to treat cancer and not aim to do everything in our power to make it work."

The Queen's researchers will receive the Commendation in the Cardiovasular Innovation Award at the Medical Futures Innovation Awards in London June 6, 2011. The Awards are one of Europe's most prestigious healthcare and business awards, rewarding innovative ideas from front line clinicians, scientists and entrepreneurs. Professor Shaw's team are the only entry from Northern Ireland to be successful at this year's awards.

Congratulating Professor Shaw and his colleagues, Professor Brian Walker and Dr Tianbao Chen, on their commendation award, Queen's Vice-Chancellor Professor Peter Gregson said: "This award is not only an honour for Professor Shaw and his team, it is recognition of the world-class research taking place at Queen's School of Pharmacy, and the life-changing potential of the University's work in drug discovery."

Biologia 12

Ficha de Leitura nº 8 Data:07/06/11

Unidade de Ensino: Imunidade e controlo de doenças

Conteúdo/assunto: A presença de certas proteínas podem parar ou activar a proliferação celular

Título: Scientists Uncover Role for Cell Scaffold in Tumor Formation: Fruit Fly Reveals Surprising Link

Resumo: Uma equipa de investigação do Instituto Gulbenkian de Ciência, liderada por Florence Janody, descobriu uma ligação entre o “esqueleto” das células e o tamanho dos órgãos. Determinadas proteínas do esqueleto da célula (proteína actin-capping) funcionam como inibidores de uma proteína (Yorkie) que quando está presente na célula activa o gene do núcleo que contém a informação que determina a proliferação celular. Com esta descoberta de uma equipa portuguesa, a ciência está mais perto de encontrar uma cura para o cancro.

Fonte: http://www.sciencedaily.com/releases/2011/06/110606075639.htm (cons:07/06/2011)

Pesquisador: David Alecrim

Scientists Uncover Role for Cell Scaffold in Tumor Formation: Fruit Fly Reveals Surprising Link

During development of an embryo, cells proliferate and organs grow. This process is tightly regulated, at several levels, to ensure that organs do not outgrow the body they are in. One of the key regulators in this process is the Hippo complex of proteins -- first identified in the fruit fly Drosophila melanogaster. Mutant flies, in which this complex is defective are larger than their counterparts -- they are hippopotamus-like. A search for analogous genes uncovered a similar role for the Hippo complex in mammals -- organs grow larger than they should. In adults, this abnormal and untimely growth often leads to tumour formation.

A flurry of papers has shown that the Hippo complex itself is regulated by a range of signaling inputs within the cell. Florence Janody's group identified a new, and unexpected input: the cell skeleton (called cytoskeleton), in particular one of its proteins, the actin-capping protein.

Using Drosophila larvae, the IGC team showed that when the actin-capping proteins are inactive, there is overgrowth of tissue in the area that will become the adult wing. This growth is reminiscent of tumour formation. The researchers dissected the different steps in the process that lead to abnormal growth. Inactivating actin-capping proteins leads to accumulation of actin, a major component of the cytoskeleton; this reduces the activity of the Hippo complex, leaving another protein, Yorkie, free to act on the DNA in the nucleus, turning on proliferation genes.

The cytoskeleton serves several functions in a cell: it provides structure, motility (allows cells to move, change shape and divide) and membrane traffic (transport of proteins and other large molecules within the cell). The actin protein forms cables that crisscross the cell. The cables are constantly being elongated and shortened at their ends. The actin-capping proteins are involved in this process.

In Florence's words, ' What we've revealed is that the cytoskeleton needs to be very tightly regulated within the cell, to prevent abnormal growth in the larvae. Since Hippo is also turned on in the adult and in mammals, we believe these findings provide insights into how this process may be manipulated in human cells, with a view to preventing tumour formation, or blocking its progression'