Can cancer cells transform normal host cells into malignant cells?

Abstract

Summary A human prostate tumour cell line, LNCaP C4-2, when injected into athymic male nude mice, produced tumours containing:(1) only human cancer cells similar to those injected; (2) only murine stromal cells containing abnormal chromosome constitutions; or (3) both human prostate cancer cells similar to those injected and the transformed murine stromal cells with altered chromosome constitutions.Karyotypic analysis of murine metaphases from all the host-derived tumours showed mostly pseudodiploid chromosome constitutions, with multiple copies (amplification) of mouse chromosome 15 and the absence of a typical Y chromosome. Fluorescence in situ hybridization analysis of these murine cells, using a biotin-labelled total human DNA painting probe, further demonstrated the absence of human DNA and the presence of only mouse metaphase and interphase cells in these transformed stromal cells. These results suggest that cancer cells are capable of inducing neoplastic transformation in stromal cells of the host organ by some, as yet unknown, epigenetic mechanism(s).Keywords: malignant transformation; tumour-stroma interaction; fluorescence in situ hybridization; pseudodiploid karyotype; prostate cancer progression; epigenetic mechanism of carcinogenesis Although the athymic mouse and rat are not natural hosts for the study of the in vivo biology of human neoplasms, they provide excellent models for the growth and maintenance of human tumours in vivo (Fidler, 1986) and for the study of reciprocal cellular interaction between tumour cells and host stroma (Wu et al, 1994). For many tumour biology experiments, the nude mouse routinely serves as a 'biological incubator' for primary and established tumour cells for selecting derivative cell lines with differing metastatic properties and for therapeutic trials monitoring tumour growth and levels of tumour or serum biomarkers (Fidler, 1986(Fidler, , 1990. The focus of the present communication is to document the tumour-stroma interaction that resulted in the induction of host stromal cells to assume non-random genetic alterations.When human tumour cells are injected into nude murine animals, quite frequently human tumour cells grow, but other possibilities also exist (Treit et al, 1980;Goldenberg and Pavia, 1981;Bowen et al, 1983;Hsu and Pathak, 1989;Gupta et al, 1990). In earlier experiments in which we injected human breast cancer cells into the nude mouse, the tumours produced in the host consisted of mouse cells with abnormal metaphases containing double-minute chromosomes (Bowen et al, 1983). Three types of tumour cells were harvested from such an experimental tumour model: (1) The purpose of this study was to investigate whether there were specific cytogenetic abnormalities present in several murine stromal tumours that developed after the injection of human C4-2 tumour cells that metastasized as bony tumour deposits (Thalmann et al, 1994;Wu et al, 1994). We report here cytogenetic findings from the resulting host stromal tumour cell lines from six athymic mice bearing...

Malignant transformation of host stromal fibroblasts derived from the bone marrow traced in a dual-color fluorescence xenograft tumor model

“…Furthermore, recent findings suggested that certain functional human genes may be involved in the malignant transformation of stromal cells (49,50). This view is also supported by other investigators (53)(54)(55). However, as shown above, two of the transformed cells cloned in the present study are of mouse origin, and only mouse chromosomes were observed.…”

“…However, as shown above, two of the transformed cells cloned in the present study are of mouse origin, and only mouse chromosomes were observed. However, as reported by Pathak et al (53) and Jacobsen et al (54), it is possible that the tumor cells first fused with the stroma cells, led to loss of the tumor cell chromosomes. It has been argued that stimulation with cytokines such as IL-6, GM-CSF and IL-4 is a potential mechanism underlying the malignant transformation of stroma cells (32,56).…”

Coculture with Prostate Cancer Cells Alters Endoglin Expression and Attenuates Transforming Growth Factor-β Signaling in Reactive Bone Marrow Stromal Cells

“…For example, when bone marrow stromal cells are coinoculated with the poorly tumorigenic prostate cancer cell line LNCaP, the prostate cancer cells progress to a more tumorigenic phenotype (20,21,24,25). The enhanced tumorigenicity is the result of changes in genotype and phenotype of both the prostate cancer cells and the host stromal cells (19,22,23,26,27). Interestingly, extracted stromal cells that have been in contact with tumor cells retain the ability to transform nontumorigenic cells, indicating that the phenotypic and genotypic alterations of the stromal cells are permanent (28).…”

Gross Chromosomal Aberrations are Early Alarms for Malignancy: A Re-Emphasis

“…Wherever chromosomal changes take place, there ought to be imposed effects within the cells where they occur; even malignancy is affected by other cells [25,26] as these might become sensitive / prone to mutagenesis. This is not only true for cancer cells but many kinds of chromosomal deviations (structural and or numerical) have been recorded in lower frequencies (2 to 4%) among seemingly normal persons in the population [15,19,[22][23][24].…”