Use of fixed contact-sensitive monolayers for identification and separation of normal from neoplastic cells

Summary

Confluent monolayers of a contact-sensitive Balb/c 3T3 cell line were fixed with 3% glutarladehyde to produce fixed contact-sensitive plates (F-CSPs). The growth of first passage human fibroblasts and neoplastic cells superinoculated onto F-CSPs was then compared with the growth of these cells on plastic culture plates. [³H]-thymidine (TdR) incorporation by fibroblasts on Day 3 after inoculation onto F-CSPs was lower than after inoculation onto plastic plates. The [³H]TdR incorporation ratio (Day 7/Day 3) of fibroblasts grown on F-CSPs was also lower than that of cells grown on plastic plates. Moreover, both the absolute [³H]TdR incorporation and the [³H]TdR incorporation ratio of first passage fibroblasts were lower than those of contact-sensitive fibroblast cell lines (10T1/2 and 3Y1) grown on F-CSPs. These results indicated that the attachment and proliferation of first passage human fibroblasts on F-CSPs were both very poor. In contrast, first passage human neoplastic cells (K-M and Br-M cells) showed greater attachment and proliferation on F-CSPs than on plastic plates. On Day 7 after inoculation, the growth ratio of these neoplastic cells vs. that of first passage fibroblasts was approximately 34-fold higher on F-CSPs than on plastic plates. On F-CSPs, first passage human fibroblasts exhibited contact sensitivity and did not proliferate, whereas neoplastic cells continued to grow because they lacked contact sensitivity. This differential growth of cells on F-CSPs may provide a method of separating normal and malignant cells from primary human carcinoma specimens.