Enhancing factor (EF), a mouse phospholipase A₂ (PLA₂), has been purified from the small intestines, based on its ability to increase the binding of epidermal growth factor in a radioreceptor assay. EF/PLA₂ was found to be localized predominantly in the Paneth cells in the small intestines. Whether mouse intestinal EF/PLA₂ is identical/similar to mouse secretory PLA₂ was to be determined. Phospholipases are known to play a crucial role in the process of inflammation. This paper reports the presence of trace amounts of EF/PLA₂ in the peritoneal exudate cells. Western blot analysis of the acid extracts showed the presence of a 14 kDa immunologically cross-reactive protein. RT-PCR analysis using EF specific primers amplified a ∼700 bp product which was further confirmed to be EF-specific by nested PCR analysis and sequencing. Presence of EF in the peritoneal exudate cells could be a unique mode of transport of growth factor modulator to the site of injury to aid in regeneration/cell proliferation of damaged tissue.

Enhancing factor (EF), a mouse intestinal phospholipase A₂ (PLA₂), has been isolated and characterized. EF increases the binding of epidermal growth factor (EGF) to A431 cells almost two-fold by interacting with EGF. EF binds to a 100 kDa cell surface receptor and brings about an increase in the binding of EGF. In the present study we demonstrate that EF is a heparin binding protein and at the time of iodination of EF, the heparin binding site of EF has to be protected. Heparin inhibits the enhancing activity of EF as well as the binding of labelled EF to A431 cells. Inhibition of binding of EF to cells by heparin indicates that heparin binding region forms at least part of the receptor binding domain. These data suggest that the receptor for EF on the cell surface could be a heparin sulphate proteoglycan.

Enhancing factor (EF) protein, an isoform of secretory phospholipase A₂ (PLA₂), was purified as a modulator of epidermal growth factor from the small intestine of the Balb/c mouse. It was for the first time that a growth modulatory property of sPLA₂ was demonstrated. Deletion mutation analysis of EF cDNA carried out in our laboratory showed that enhancing activity and phospholipase activity are two separate activities that reside in the same molecule. In order to study the specific amino acids involved in each of these activities, two site-directed mutants of EF were made and expressedin vitro. Comparison of enhancing activity as well as phospholipase A₂ activity of these mutant proteins with that of wild type protein helped in identification of some of the residues important for both the activities.

Role of heredity and lifestyle in sporadic cancers is well documented. Here we focus on the influence of low penetrance genes and habits, with emphasis on tobacco habit in causing head and neck cancers. Role of such gene-environment interaction can be well studied in individuals with multiple primary cancers. Thus such a biological model may elucidate that cancer causation is not solely due to genetic determinism but also significantly relies on lifestyle of the individual.

Low back pain due to degeneration of intervertebral disc (IVD) is a major health problem resulting insignificant disability as well as adding to the economic burden. Discectomy is a very common procedure doneworldwide to relieve this pain. At present all the surgically removed disc tissue is mostly discarded. However,there are reports that state that progenitor cells in the IVD can be grown ex vivo and have the potential to beused for IVD repair and regeneration. We report here that viable cells can be harvested from surgicallyremoved, herniated disc tissue and can be potentially used in cell based therapy. Further, we have successfullyreplaced xenogenic supplements such as foetal bovine serum with either autologous serum or human plateletlysate for culturing IVD cells from patient’s surgically removed disc tissue, without loss of any cell characteristics,including cell surface markers, growth factor secretion in the conditioned medium and osteogenic andchondrogenic differentiation potential in vitro. The present work will not only contribute to overcoming someof the major barriers in carrying out human clinical trials, but also provide a cheap, alternate source of proteinsand growth factors for growing IVD cells ex vivo for therapy.