In vitro transformation of cell lines from human salivary gland tumors

Abstract

Explanted cells from salivary gland tumors are particularly difficult to propagate in vitro and not efficiently immortalized by agents such as simian virus 40. Human papillomavirus 16 (HPV16) has been widely used to transform cells of epithelial origin, but its use for salivary gland cell transformation has not been described. In this study, we employed viral constructs containing the E6/E7 genes of HPV16 to infect and stably transform 9 salivary gland tumor cell cultures. Four of the tumor cell cultures were derived from benign tumors and 5 from malignant tumors. All of the original cell cultures were diploid; however, 6 contained subpopulations of cells with structural abnormalities. All 9 cell cultures were successfully transformed, and 8 were immortalized. The resulting cell lines have decreased serum requirements, exhibit a high proliferation rate, are E6/E7‐positive and form colonies in soft agar. Immuno‐histochemical and molecular studies confirmed that the transformed cells were indeed epithelial/myoepithelial in origin. All of the transformed cell lines had a diploid or near‐diploid karyotype, and 2 contained the original translocated chromosomes in all cells. Our report represents a new application of the E6/E7 system in immortalizing salivary gland cell cultures, resulting in retention of the cellular features found in the native tissue without a general destabilization of the karyotype. These types of tissue culture resources should prove useful for positional cloning and functional studies of genes involved in salivary gland oncogenesis. Int. J. Cancer 81:793–798, 1999. © 1999 Wiley‐Liss, Inc.

Isolation, immortalization, and characterization of a human breast epithelial cell line with stem cell properties

“…However, we cannot at present exclude some loss of K19 + cells in the MUC + / ESA + cell line during immmortalization. Finally, human salivary gland cells transduced with E6/E7 were reported to remain diploid or near-diploid without a general destabilization of the karyotype (Queimado et al 1999). We have confirmed these studies, and have found that the transduced breast cells are nontumorigenic and have a diploid karyotype (46, XX; T. Gudjonsson and C. Jin, unpubl.…”

Alternative splicing of the imprinted candidate tumor suppressor gene ZAC regulates its antiproliferative and DNA binding activities

“…This protein was found to be nuclear (Figure 2c) indicating that amino acids 1 ± 52 do not contribute to the nuclear localization of ZAC. The existence of a splice variant devoid of the exon encoding the 2 N-terminal ZFs has been reported for PLAG1 (Kas et al, 1997;Queimado et al, 1999), a member of the ZAC family of zinc ®nger proteins whose 3' gene structure is similar to that of ZAC. In contrast to ZAC, PLAG1 splice variant is devoid of the putative nuclear localization signal (Kas et al, 1997).…”

Development and characterization of salivary adenoid cystic carcinoma cell line

“…[25-28] Although successful transfection was achieved, cytogenetic analysis of subsequent passages of transfected cells lacked the t(6; 14). Comparative analysis of h-TERT immortalized cells with primary tumor resulted in concordant random alterations including gain of chromosome 8 and focal 14q loss.…”