A BALB/c 3T3-transformed cell line suitable for transfection assay of metastasis-inducing genes

Abstract

A clonal cell line, 1-1ras1000, transformed by the activated c-Ha-ras oncogene, does not form metastases after i.v. injection into mice (experimental metastasis assay). Here, we show that this cell line is useful as a recipient to detect metastasis-inducing genes, using a transfection assay. Cells (1-1ras1000) were susceptible to metastasis induction by transfection with either v-src or genomic DNA from a v-src-and v-fos-transferred highly metastatic rat cell line (SR202). The susceptibility of 1-1ras1000 cells for lung metastasis induction was suitable for a genomic transfection assay to detect a metastasis-inducing gene in the transfected cells which had incorporated genomic DNA from donor meta-static tumor cells. When DNAs extracted from 7 human tumors were tested for metastasis induction, 2 DNAs from nonmalignant tumors (non-tumorigenic tumors in athymic nude mice) (2/2) were negative and 4 DNAs from malignant tumors (4/5) were positive in 1-1ras1000 cells for primary transfection. In one of the resulting metastases, the ability to metastasize was also transferred in the second and third cycles of genomic DNA transfection at high frequencies. All of the resulting metastases carried the human repetitive Alu sequence. Neither rearrangements of the endogenous c-Ha-ras nor changes of protein amounts were detected. Recipient 1-1ras1000 cells had a negligible rate of spontaneously meta-static conversion during in vitro cultivation and transfection processes. The resulting metastasized cells were easily isolated from the lung after culturing in selection medium containing G418 (geneticin). Isolated cells stably retained the ability to form metastatic lung nodules when re-injected into mice. Thus, 1-1ras1000 cells appear to be a useful system for the isolation of metastasis-inducing genes from human meta-static tumors. Int. J. Cancer, 71:88-93, 1997. r 1997 Wiley-Liss, Inc. Most primary tumors arising in the body are thought to have no ability to spread invasively. In these tumors, at the final stages of development and progression, a metastatic subpopulation of tumor cells that can form discontinuous tumors at sites near to or distant from the primary site may appear. Such a cell population, with metastatic potential, is distinct from the primary tumorigenic cell population (Fidler and Hart, 1982; Talmadge and Fidler, 1982; Schirrmacher, 1985). One paradigm about tumor progression proposes that a finite number of non-random chromosomal alterations and genetic changes accumulate and are responsible for each step of multiple-stage carcinogenesis (Vogelstein et al., 1988), including metastasis (Dear and Kefford, 1990; Liotta et al., 1991). The metastatic conversion of non-metastatic tumor cells appears to be controlled at 2 levels of genetic activity. The first is where genes act dominantly to induce metastasis, e.g., variant type CD44 (Gunthert et al., 1991) and TIAM1 (Habets et al., 1994). The second is where genes act as metastasis suppressors. Loss of the genes predisposes metastatic conversion from the non-metast...

Overexpression of Aurora-A potentiates HRAS-mediated oncogenic transformation and is implicated in oral carcinogenesis

“…Recently, a single-nucleotide polymorphism (SNP) of Aurora-A at position 91 (T91A encoding Phe31Ile) was identified, making Aurora-A a low-penetrance tumor-susceptibility gene susceptible to amplification (Tatsuka et al, 1997). For the detection of endogenous Aurora-A, monoclonal anti-Aurora-A antibody (BD PharMingen) was used.…”

Incorrect strain information for mouse cell lines: sequential influence of misidentification on sublines

“…Eight cell lines had been believed as subclones of the BALB/3T3 clone A31 cell line derived from the BALB/c strain (Kakunaga and Crow 1980; Sasaki et al 1988, 1990; Tatsuka et al 1996, 1997). However, SSLP analysis of these 8 samples showed 2 different lengths for 2 or 3 loci, indicating that they did not originate from an inbred strain (Table 5).…”

Activation of Rac1 by Rho‐guanine nucleotide dissociation inhibitor‐β with defective isoprenyl‐binding pocket

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