Bulletin Autumn‧Winter 1997

HIGHLIGHTS OF RGC-FUNDED PROJECTS distress. A n y changes b e y o n d that can be life-threatening. The researchers found that hyperthermia, through an as yet unknown mechanism, increases the acidity in the t umo ur cells. As a result D N A a nd p r o t e in synthesis is affected, and the proliferation and growth of tumour cells are reduced. Nucleophosphoprotein B23 in Tumour Cells Translocated The function of B23 ， a phosphoprotein found in the nucleolar compartment of cells, is to maintain the norma l assembly of ribosomal RNA in order t o facilitate synthesis of cellular proteins. The study found that hyperthermia lowers the level of B23 in nucleoli and translocates it, leading to cell death. These effects are similar to the action of certain effective anti-tumour drugs such as d o x o r u b i c i n. The researchers are currently studying the relationship between B23 — its reduction and translocation — and the growth of tumour cells, focusing in particular on that between B23 and heat shock proteins under hyperthermia, as well as possible synergistic effects of drugs and hyperthermia in the treatment of cancer. Research to Continue The foregoing discoveries point cancer treatment i n a n ew direction. Howe v e r , as b o t h researchers po i n t ed out , hyper- thermotherapy is still in its research stages, far removed from clinical application. The research team received a further grant of HK$310,000 from the Research Grants Council in 1995 to continue their study on The Mechanism of Combination Treatment of Tumour Necrosis Factor- α and Hyperthermia on Tumou r Cells'. Tumour necrosis factor- α (TNF- α ) is a special kin d of protein released by the human immune system to kil l cancer cells. Through genetic engineering, TNF- α can be manufactured as an anti-cancer drug. The researchers now focus their attention on th e combined use of hyperthermia and TNF- α , in particular the optimal protocol for applying heat to minimize the side effects of hyperthermia on normal cells. They will also study the effectiveness of combination treatments of h y p e r t h e r m ia and c h emo t h e r a p y or immunotherapy. The results of these studies may provide useful information on the best mode of applying hyperthermia i n clinical settings. A recent as yet unpublishe d observation is that hyperthermia when used with TNF- α can effectively suppress the growth of breast cancer cells, and that the order of TNF- α injection and the application of heat c a n a f f e ct t r e a t m e nt r e s u l t s . A n o t h e r significant finding is that hyperthermia can enhance the entry of Taxol (a new drug for breast cancer) in breast cancer cells to augment the cytotoxic effect of the drug. These and other findings of the research will be published i n due course, to assist med i ca l scientists to devise the best treatment strategy for different cancers.• The effect of hyperthermia on translocation of B23 proteins in Ehrlich ascites tumour cells, as observed in immunofluorescence photomicrographs of tumour cells after treatment for two hours. Control cells after treatment at 37°C show the presence of B23proteins in the nucleoli (seeA). Tested cellsafter treatment at 43。Cshow reduced content (seeB).or absence of B23proteins in the nucleoli (see C). Chinese University Bulletin Autumn • Winter 1997 22