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111

Mesa-nt of Cell Rollferatlon in NSCLL cell lines using

Growth ch&cteristlcs of human tumour cell populatlona is eaaentlal knowladae for de&n of more effective aumoachaa to

aamaldemblenumberoftumomceB3am

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tumoumbannayin~cehuhr. blc&&aland&‘F: Such measuremen s relv on the asaumutlon that a so d tumour lar ely contains tumoti cells, and do itot take Into account the ce&armfmaMmeofthetommu@odvaaaela,akomalcelleand inflammatory calls). We have found that a large variation in tumomcaBmntentoccwafxomapedmentoapedmenwlthamnge of 442% of identifiable tumour cells. We charactedzed and

cella anatysia.

am viabli and can be used for subsequent experhnental

112

IMPLICATION OF THE 6 RECEPTOR OF RERNOIC ACID IN EPIDERMOID LUNG CANCER.

Benoit Houle and W.E.C. Bradley, lnstitut du cancer de Montreal, Montreal, Quebec, Canada.

Lung tumor cells are characterized by a consensus deletion of the short arm of chromosome 3 (3~). Among the genes known to map in this region is RAR3, which codes for a nuclear receptor for retinoic acid. We have studied the expression of RAR6 in cell lines derived from lung tumors. Our results show that RARp is expressed in normal lung tissue and in most of the cell lines studied, wlth the striking exception of 5 out of 6 cell lines characterized by an epidermoid (squamous) differentiation. To study the possible role of RAR6 in epidermoid lung tumorigenesis, we have generated transfectants expressing RARp from two epidermoid tumor- derived cell lines which do not express RAR6 (CALU-1 and NCI-H157). The results of tumorigenicity assays in nude mice indicate that the transfectants expressing RARp are dramatically less tumorigenic than the corresponding parental cells. In the few instance where tumors developed, they were characterized by either a greatly reduced rate of growth, an increased lag time, regression, or a combination of these. These results support the hypothesis that RAR$ functions as a tumor suppressor gene in epidermoid lung carcinogenesis.

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Variation in the immune system in pa- tient with polmonary carcinomas

Bini A.,Grazia M.,Stella F.,Fiacchi M., Ombrellino M., Bazzocchi R., Thoracic Surgery - Emergency Surgery Univer- versity of Bologna - Italy

It is clear that in neoplastic disease we can observe alteration of the immune system which may be studied utilizzing different diagnostic approaches which are more or less sensitive. The study by us concluded in patients with polmonary carcinomas (27 cases),presented us with different linfocite subclasses utiliz- zing circulating immunocomplexes CD3+,CD4+, CD8+,CD4+/CD8+,IgE,IgA,IgM. The results obtai- ned by us showed a statistically significant increase in the percentage of activated T lin- focites and an equally significant decrease in B linfocites. Our study also showed asignifi- cant increase in the CD57+ population sustai- ned ned from CD57+,CD8- with natural killer(PIK) activity. In conclusion the data studied has showen an activation of the immune system with utilizzes natural killer cells with were reco- gnized as the effector cells of the antineopla- stic activity. Our intent is to continue the

study of immune system during follow-up.