By Sara Ledwith CAMBRIDGE, England (Reuters) - Rising up from the fields around the university city of Cambridge, the steel towers of the Laboratory of Molecular Biology, are scientific pillars in the defense that drugs group AstraZeneca is mounting against a takeover approach by its U.S. rival Pfizer. The lab's four towers - clearly visible from arriving trains - help keep vibrations and noise away from highly sensitive equipment. Scientists who work there have said it is "simply too dangerous" to let AstraZeneca be bought by the American group. AstraZeneca plans to move its own research and corporate headquarters to the plot next door to the lab, which has earned 10 Nobel prizes. The company is emphasizing a strategic research alliance it has agreed with the laboratory's owner, the publicly funded Medical Research Council (MRC). AstraZeneca says it wants the relationship to be symbiotic. The group - subject of a $100 billion-plus bid approach from Pfizer - hopes the collaboration can help accelerate the development of new, ground-breaking drugs and revitalize its business, placing it at the core of a growing cluster of expertise around Cambridge. The site is due to be completed in 2016. Other large drugmakers have built research outposts in Cambridge and U.S. life science centers like Boston and San Francisco, but none have undertaken such a wholesale move of operations. While Pfizer says it will complete the planned research center if it buys AstraZeneca, it has not said how many staff it will have in Cambridge or elsewhere. AstraZeneca's Cambridge ambitions go further than simply relocating its scientists and top management in a leading university town. Under the deal with the MRC, the drugmaker will give academics access to more than two million molecules in AstraZeneca's compound library, which they can develop as they will, giving AstraZeneca first refusal on any potential drugs. "This is what I've always asked for," said Hugh Pelham, director of the biology lab, which is known as MRC LMB. The arrangement will appeal to scientists' professional ambitions, by encouraging research for publication in scientific journals, "crossing the road between academia and industry" and even stimulating some to start their own companies, he told visiting journalists last week. CYCLING TO WORK When it comes to sparking great scientific ideas, much depends on human connections which have been years in the making, Pelham said. AstraZeneca's small existing biotech operation in Cambridge, known as MedImmune, has roots going back 25 years to the time when a scientist-led company, Cambridge Antibody Technology, was spun out from the big MRC biology lab. "There are people there that we know. People are married to people there," Pelham said. Being near to each other - cycling to work together - is a "very significant cultural feature of Cambridge". More than 1,600 firms have been created as a result of collaborations between academia and the private sector in Cambridge, and the university's 4.9 billion pounds ($8.25 billion) collective endowment is Europe's largest. AstraZeneca's collaboration with MRC LMB will help Cambridge compete for pharmaceutical innovation, said Mene Pangalos, AstraZeneca's Executive Vice President, Innovative Medicines & Early Development. The company's new headquarters, designed to have multiple entrances, will be "very porous and very permeable to the academic community" and look in onto a courtyard like one of the city's historic colleges, he added. Academic and corporate scientists will work side by side, with perhaps only the logos on their lab coats to distinguish them. Pangalos, who previously worked at Pfizer, avoided comparing the two companies' approach. But he said AstraZeneca was centered now on science-driven innovation, and a collaborative approach. "This takes years of relationship building and it's also quite fragile," Pangalos added. "If you destabilize that - turn it on its head - I think that will have a huge detrimental effect on the UK." ($1 = 0.5942 British Pounds) (Additional reporting by Ben Hirschler; editing by Anna Willard)