Tracing the in vivo distribution and dynamics of cancer cells in mice by luminescence of aequorin- expressing transformants.

In order to trace the in vivo dynamics of cancer cells, we introduced jellyfish aequorin cDNA into metastatic (A-11) and nonmetastatic (3LL) Lewis lung cancer cell lines. The transformants (e.g.

Ca2+-dependent, Fas- and perforin-independent apoptotic death of allografted tumor cells by a type of activated macrophage.

Both perforin- and Fas ligand (FasL)-deficient CTLs show impaired lytic activity toward most target cells. In this study, we examined whether these molecules could be involved in the cell-to-cell contact-dependent cytotoxicity mediated by macrophages infiltrating into the rejection site of allografted Meth A fibrosarcoma cells. FasL-expressing lymph node cells from MRL-lpr/lpr mice were inactive toward Meth A tumor cells.

Inositol-phosphoglycan inhibits calcium oscillations in hepatocytes by reducing calcium entry.

Inositol-phosphoglycan (IPG) is a putative mediator of insulin action that has been shown to affect numerous biochemical processes. IPG, prepared from liver membranes, promptly inhibited phenylephrine- or vasopressin-induced [Ca2+]i oscillations when perfused over Fura-2-dextran injected rat hepatocytes. An antibody to IPG suppressed the inhibitory effect of insulin on the [Ca2+]i oscillations.

Multiple expression of Ly-6C and accumulation of a Ly-6C pre-mRNA in activated macrophages involved in rejection of an allografted tumor.

We established a monoclonal antibody against a surface antigen of activated macrophages (Møs) involved in the rejection of an allografted mouse tumor, Meth A. Bacteria-elicited Møs also expressed the antigen but resident or inflammatory Møs, or other leukocytes, did not. The antigen was identified as Ly-6C by isolation of cDNA clones encoding it.

Regeneration and luminescence of aequorin in Chinese hamster ovary cells transformed with cDNA for apoaequorin.

Aequorin, a photoprotein which is regenerated from apoaequorin by incubation with coelenterazine, emits light when it binds Ca2+. The aim of this study was to determine if apoaequorin could be used in adherent mammalian cells for measuring cytosolic Ca2+, and imaging Ca2+, at the single cell level. Chinese hamster ovary (CHO-K1) cells were stably transformed with apoaequorin cDNA and expressed apoaequorin while attached to the culture dishes.