A technique for studying anticancer drugs inside cells could help in the search for better-targeted cancer therapies.

 Trevor Hambley and co-workers from the University of Sydney, Australia, have used their new coordination-sensitive fluorescence technique to monitor platinum drugs of different coordination state - Pt(II) and Pt(IV) - inside cells. Their aim is to track the differences in how the complexes are handled by cells.

 'Platinum drugs work by binding to DNA but they do so in healthy cells as well as tumour cells, causing toxicity,' explains Hambley. So whilst Pt(II) complexes such as cisplatin are active against cancer, their toxicity to healthy cells can also lead to side effects. The advantage of Pt(IV) complexes is that they are much less reactive than Pt(II), but they reduce to form the highly active Pt(II) species. If Pt(IV) drugs could be reduced to Pt(II) only once they are inside a tumour, they should be effective against cancer while having low toxicity.

 But, as Ulrich Bierbach, who researches platinum anticancer drugs at Wake Forest University, North Carolina, US, explains, little is known about how these drugs act in the cell, despite many years of intense research. Approaches such as Hambley's help to trace the pathways these complexes take inside cancer cells so the method 'will ultimately help improve the pharmacological properties of current and future platinum-based therapies,' says Bierbach.

 Hambley's group made Pt(II) and Pt(IV) complexes containing a fluorescent ligand and treated cancer cells with them. By using confocal fluorescence microscopy to study the fluorescence in the cells, the researchers found that the Pt(II) complexes showed higher fluorescence than Pt(IV), and when Pt(IV) is reduced to Pt(II), there is an increase in fluorescence. 'We used differences between the images to gather information on how the compounds are handled by the cells,' explains Hambley.

 Hambley says that he hopes to track where in the cell Pt(IV) complexes are reduced to Pt(II), by monitoring fluorescence changes over time. The group is also working on strategies for restricting Pt(IV) complex reduction to the tumour environment.

 Anticancer drugs are medicines used to treat various kinds of cancer. Canceris the uncontrolled growth of cells that interfere with the growth of healthycells. The approach to treating cancer depends on where in the body it occurs, the type of cells making up the cancer, and how advanced the cancer is. The usual treatments are surgery, chemotherapy (treatment with anticancer drugs), radiation, or some combination of these methods.

 Anticancer drugs interfere with the growth of tumor cells, eventually causingtheir death. However because these drugs are so powerful, they may also affect the growth of normal body cells, causing many side effects, some of whichmay be serious. Anticancer drugs come in different forms, depending on the type of drug. Some are given only as injections; others are taken by mouth in tablet or liquid form.

 The recommended dosage depends on many factors, such as body weight or kidneyfunction, and is different for different patients. Patients who take anticancer drugs at home should follow their physician's orders or the directions onthe label. Always take anticancer drugs exactly as directed. Never take smaller or larger, more frequent or less frequent doses. Take the drug for as long as it has been prescribed--no more and no less. Some drugs need to be takenat a specific time of day to be most effective and to reduce the chance of side effects. Be sure to follow these directions carefully.

 Anticancer drugs are sometimes given together with other medicines.When usinga combination of medicines, be sure to take each at the correct time. Do notmix the drugs together. Anyone who has trouble remembering when to take eachdrug should ask his or her health care team for tips on ways to keep track.

 Anticancer drugs may cause a variety of side effects, some very serious; others not as serious, but still troubling. In addition, some unwanted effects may not appear until months or years after the drugs were used. It is importantto understand what side effects are possible and to weigh the advantages ofusing this medicine with the risks of side effects. Health care professionalscan help patients sort out the relative risks and benefits. It is also veryimportant to see the physician as often as directed so that he or she can make sure the medicine is working and check for unwanted effects that may not beobvious to the patient.

 Nausea and vomiting are common side effects of anticancer drugs. However, other drugs may be given along with them to reduce these often incapacitating side effects. Unless a physician has said to stop taking the medicine, patientsshould always keep taking their anticancer drugs, even if they feel ill. A patient who vomits just after taking a dose of an anticancer drug should checkwith the health care professional in charge to find out whether to take another dose immediately or to wait until the next scheduled dose. Some anticancer drugs cause loss of hair, which may include eyebrows, eyelashes, and pubichair. This is a temporary effect. The hair should grow back normally after the treatment ends, but the color or texture of the new hair may be slightly different.

 Anticancer drugs may interact with a number of other medicines. When this happens, the effects of one or both of the drugs may change or the risk of sideeffects may be greater. Anyone who takes anticancer drugs should let the physician know all other prescription or non-prescription (over-the-counter) medicines he or she is taking. The physician should also be told if the patient has been treated with radiation or has taken other anticancer drugs.

 Many anticancer drugs cause sterility, which may be permanent. Anyone takinganticancer drugs (or who has recently taken the drugs) should not have any vaccinations (immunizations)without the approval of the physician who is overseeing the cancer treatment. These patients must also avoid contact with anyonewho has recently taken oral polio vaccine, as there is a chance the polio virus could be passed on. No one in the patient's household should take oral polio vaccine. All these precautions are necessary because anticancer drugs maylower the body's resistance to infection.