The expression of the platelet-derived and transforming growth factor genes in human nonsmall lung cancer cell lines is related to tumor stroma formation in nude mice tumors.

Human lung cancer could be separated into two major groups, small cell lung cancer (SCLC), or non-SCLC based on morphology, biochemical profile, and clinical management. The SCLC group is characterized by a wide spectrum of neuroendocrine markers, while the non-SCLC group is defined by epithelial markers. The non-SCLC cell lines studied have also been demonstrated to express elevated mRNA levels for platelet-derived growth factors and transforming growth factors, while SCLC cell lines were negative for these genes. Four human SCLC cell lines and six human non-SCLC cell lines were inoculated into seventeen nude mice. All studied tumors from the non-SCLC cell lines demonstrated prominent fibrous stromata, although with variability between the individual cell lines. The SCLC cell lines were deprived of significant stroma reaction. These findings may be of importance in explaining the biologic and clinical differences between non-SCLC and SCLC.