Motogenic effect of recombinant HGF on airway epithelial cells during the in vitro wound repair of the respiratory epithelium

Cell migration is the earliest mechanism involved in the wound repair process of the respiratory epithelium and could be potentially enhanced by growth factors. In the present work, we investigated the localisation of the hepatocyte growth factor (HGF) receptor (c-Met) during wound repair and evaluated the effect of recombinant HGF (rHGF) on cell migration by using an in vitro model of airway epithelial wound repair. By using immunohistochemical methods, we observed that the immunoreactivity of the c-Met proto-oncogene was increased in epithelial cells engaged in the process of tissue repair. The incubation of wounded cultures with increasing concentrations of rHGF (0.2, 2, 20, and 200 ng/ml) induced a significant (P < 0.02) dose-dependent effect on the wound repair index, with a maximum effect produced at 20 ng/ml (+31.3%). The cell migration speed reached 50.2 micrometer/h at this concentration, compared to 20.4 micrometer/h in the absence of rHGF. No significant effect on cell proliferation was observed in the repairing area in the presence of rHGF. These results suggest that rHGF is able to improve the wound repair process of the airway epithelium by increasing cell migration.

Motogenic effect of recombinant HGF on airway epithelial cells during the in vitro wound repair of the respiratory epithelium

Cell migration is the earliest mechanism involved in the wound repair process of the respiratory epithelium and could be potentially enhanced by growth factors. In the present work, we investigated the localisation of the hepatocyte growth factor (HGF) receptor (c-Met) during wound repair and evaluated the effect of recombinant HGF (rHGF) on cell migration by using an in vitro model of airway epithelial wound repair. By using immunohistochemical methods, we observed that the immunoreactivity of the c-Met proto-oncogene was increased in epithelial cells engaged in the process of tissue repair. The incubation of wounded cultures with increasing concentrations of rHGF (0.2, 2, 20, and 200 ng/ml) induced a significant (P < 0.02) dose-dependent effect on the wound repair index, with a maximum effect produced at 20 ng/ml (+31.3%). The cell migration speed reached 50.2 micrometer/h at this concentration, compared to 20.4 micrometer/h in the absence of rHGF. No significant effect on cell proliferation was observed in the repairing area in the presence of rHGF. These results suggest that rHGF is able to improve the wound repair process of the airway epithelium by increasing cell migration.

Does knowledge guide practice? Another look at the management of non-small-cell lung cancer

PURPOSE

To describe Canadian doctors' beliefs about the appropriate role of chemotherapy and radiotherapy in the management of non-small-cell lung cancer (NSCLC).

METHODS

A mail survey of a random sample of Canadian respirologists, thoracic surgeons, radiation oncologists, and medical oncologists was performed. Three cases of NSCLC were described and respondents were asked to estimate the prognosis in each case and to give their treatment recommendations.

RESULTS

Responses were obtained from 234 of 330 eligible subjects (74%). Doctors' treatment recommendations varied widely. After a complete resection for stage II NSCLC, 68% recommended no adjuvant treatment, 28% recommended radiotherapy, 1% recommended chemotherapy, and 3% recommended both radiotherapy and chemotherapy. For an asymptomatic patient with stage IIIb NSCLC, 17% recommended no active treatment, 65% recommended radiotherapy alone, 16% recommended radiation and chemotherapy, and 2% recommended chemotherapy alone. For an asymptomatic patient with a stage IV NSCLC, 80% recommended no active treatment and 20% recommended chemotherapy. Doctors' beliefs about the natural history of NSCLC and its response to treatment varied widely. Seventy-five percent of respondents believed that adjuvant radiotherapy did not increase survival in stage II disease, but 25% believed that it did. Thirty percent believed that the addition of chemotherapy to radiotherapy in stage III increased survival, but 70% believed that it did not. Fifty-five percent believed that chemotherapy increased the median survival in stage IV, but 45% believed that it did not. Doctors' beliefs about the efficacy of treatment were strongly associated with their treatment recommendations.

CONCLUSION

Personal beliefs, rather than universal knowledge, currently guide the management of NSCLC in Canada.