J F Talts — Page 2 | Search PubMed

PubMed1993

Induction of mouse tenascin expression by a human sarcomatoid Wilms' tumor cell line growing in nude mice.

A new cell line from a sporadic Wilms' tumor was established and extensively characterized. In nude mice, the tumor cells rapidly formed tumors which, in histological characteristics and extracellular-matrix (ECM) composition resembled sarcomatoid Wilms' tumor. The tumor cells produced B chains of laminin, but no A chain, and laminin was deposited into the ECM in a punctate pattern typical of sarcomatoid tumors. Strong expression of tenascin was detected within the stromal ECM of the tumors. Species-specific antibodies reacting either with human or with mouse tenascin showed that tenascin was exclusively derived from mouse host cells. The human Wilms' cell line thus induced a strong stromal response with increased deposition of tenascin. The cell line may be useful for studying the behavior of sarcomatoid Wilms' tumor cells and for identifying factors that stimulate synthesis of tenascin.

Animals↗

PubMedDate not supplied

Differential expression of muscarinic subtype mRNAs after exposure to neurotoxic pesticides.

We have recently reported an increase in the density of muscarinic cholinergic receptors in mice neonatally exposed to a persistent environmental agent, dichlorodiphenyltrichloroethane (DDT), and a subsequent exposure as adults to nonpersistent toxicants, such as bioallethrin or paraoxon. Here we have examined the effects of an exposure like this on muscarinic receptor mRNA expression. Ten-day-old Naval Medical Research Institute mice received a single oral dose of DDT (0.5 mg/kg body weight). When aged 5 months, they received bioallethrin (0.7 mg/kg body weight per day for 7 days) or paraoxon (1.4 mg/kg body weight every second day for 7 days). mRNA expression of subtypes m1, m3, and m4 was studied in 7-month-old animals. Changes could only be discovered in the DDT-bioallethrin treated mice, where expression of subtype m4 was elevated in cortex and caudate putamen. Moreover, the expression pattern of the subtypes m1, m3, and m4 in mouse brains was found to be very similar to that seen in rats, except for slight differences in the pyramidal cell layer of the hippocampus, where the outermost part of the CA3 region did not show any m4 hybridization. The present study indicates that the earlier observed increase in muscarinic receptor density in mice exposed as neonates to DDT and as adults to bioallethrin can be attributed to changes in the expression of m4.

Age Factors↗