Friday, October 9, 2009

DNA Test Could Be Key To Targeting Treatments For Head And Neck Cancer

It is estimated that more than 7,000 people are diagnosed with head and neck cancer each year in the UK and approximately 3,500 cases result in death. These cancers include tumours of the mouth, lips, throat and voice-box, and some have been linked to the sexually transmitted infection, HPV-16. Scientists at Liverpool analysed the DNA of more than 90 cancerous tissue samples to look for genes that indicated infection.

The team found that nearly two thirds of tonsil tumour samples showed evidence of the HPV-16 gene. It is thought that chemical alterations in the virus's DNA trigger the production of proteins that can alter the rate at which cells grow and repair. This strongly increases the possibility of subsequent cancer development. Recent studies have found, however, that patients who have the HPV infection when they are diagnosed with cancer, respond better to chemotherapy or radiation therapy than those that do not have the infection. The work will be presented at the National Cancer Research Institute's (NCRI) Cancer Conference in Birmingham.

Mr Richard Shaw, from the School of Cancer Studies, explains: "Recent evidence demonstrates the possible involvement of HPV in the development of tonsil cancer, particularly in non-smokers. Interestingly, the treatment efficiency of chemotherapy and radiation, seems to differ between HPV positive and negative cases. We also need to find out why only a small percentage of people with this common infection develop this cancer. Our study, however, gives us a new lead towards a risk marker.

"It is thought that HPV interacts in the cell with genes controlling the chemical modification of DNA, which affects gene expression and tumour behaviour. Our study shows that HPV may be a trigger of tonsil cancer, independent of the known common causes, such as smoking or drinking. The work also suggests that a DNA test to determine the activity of HPV, could be used to identify the most effective treatment for each individual patient.

"Liverpool has the largest centralised head and neck oncology practice in the UK and our data show a doubling in the rate of non-drinkers and non-smokers presenting with tonsil cancer. As head and neck cancer is one of the cornerstones of the new CR-UK Cancer Centre in Liverpool, we are pleased to be making real progress in this area of research."

Researchers are now working to develop a clinical trial for a therapeutic HPV vaccine in head and neck cancer.

The study, supported by the Royal College of Surgeons, is presented at the NCRI Cancer Conference on Monday, 5 October.

Wednesday, October 7, 2009

Nobel Prize In Chemistry: What Ribosomes Look Like And How They Functions At Atomic Level

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2009 jointly to Venkatraman Ramakrishnan, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom; Thomas A. Steitz, Yale University, New Haven, CT, USA; and Ada E. Yonath, Weizmann Institute of Science, Rehovot, Israel, "for studies of the structure and function of the ribosome".

The ribosome translates the DNA code into life

The Nobel Prize in Chemistry for 2009 awards studies of one of life's core processes: the ribosome's translation of DNA information into life. Ribosomes produce proteins, which in turn control the chemistry in all living organisms. As ribosomes are crucial to life, they are also a major target for new antibiotics.

This year's Nobel Prize in Chemistry awards Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for having showed what the ribosome looks like and how it functions at the atomic level. All three have used a method called X-ray crystallography to map the position for each and every one of the hundreds of thousands of atoms that make up the ribosome.

Inside every cell in all organisms, there are DNA molecules. They contain the blueprints for how a human being, a plant or a bacterium, looks and functions. But the DNA molecule is passive. If there was nothing else, there would be no life.

The blueprints become transformed into living matter through the work of ribosomes. Based upon the information in DNA, ribosomes make proteins: oxygen-transporting haemoglobin, antibodies of the immune system, hormones such as insulin, the collagen of the skin, or enzymes that break down sugar. There are tens of thousands of proteins in the body and they all have different forms and functions. They build and control life at the chemical level.

An understanding of the ribosome's innermost workings is important for a scientific understanding of life. This knowledge can be put to a practical and immediate use; many of today's antibiotics cure various diseases by blocking the function of bacterial ribosomes. Without functional ribosomes, bacteria cannot survive. This is why ribosomes are such an important target for new antibiotics.

This year's three Laureates have all generated 3D models that show how different antibiotics bind to the ribosome. These models are now used by scientists in order to develop new antibiotics, directly assisting the saving of lives and decreasing humanity's suffering.

Courtesy: Sciencedaily