The bacterial colicin active against tumor cells in vitro and in vivo is verotoxin 1.

We have identified verotoxin 1 (VT1) as the active component within an antineoplastic bacteriocin preparation from Escherichia coli HSC10 studied over two decades. Recombinant VT1 can simulate the toxicity of anticancer proteins (ACP), and the antineoplastic activity of ACP (and VT1) was abrogated by treatment with anti-VT1 antibody. Similarly, VT1 mimics the protective effect of ACP in a murine metastatic fibrosarcoma model.

Augmentation of interleukin-6 (IL-6) expression in squamous carcinoma cells and normal human keratinocytes treated with recombinant anti-neoplastic protein (ACP).

A protein purified from Eschericheri coli has previously been shown to have cytotoxic effects on neoplastic cells of several lineages both in vitro and in vivo. Accordingly, this protein has been named anti-neoplastic protein (ACP). Although ACP kills neoplastic cells by inducing apoptosis, it has negligible effects on various normal cells.

Partially purified bacteriocin kills malignant cells by apoptosis: programmed cell death.

Bacterial proteins, partially purified bacteriocin (PPB), were investigated for their selective killing of malignant cells. It is shown here that upon PPB-cell interaction DNA fragmentation starts within one hour and peaks at 6 hrs. This process requires an on-going cellular metabolism.

Further studies of the action of a partially purified bacteriocin against a murine fibrosarcoma.

We have reported previously that a partially purified bacteriocin (PPB) from Escherichia coli HSC10 is toxic to KHT cells growing in vivo as micrometastases but apparently has no activity against a tumor growing i.m. We report here experiments to investigate possible reasons for this difference.