Synthetic Analogues Of The Actinomycin, Quinamycin And Nogalamycin Groups Of Antitumour Antibiotics
Funder
National Health and Medical Research Council
Funding Amount
$376,433.00
Summary
The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar ....The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar scenario in the treatment of adults with leakaemias and non-Hodgkins lymphomas. The underlying cause of drug resistance is the genetic instability of cancer cells which results in tumours that are heterogeneous, making it almost inevitable that a cancer cell will arise that is resistant to treatment. There are many mechanisms of resistance, some of which are peculiar to particular drug types, some are permeability barriers and some involve genetic deregulation of the biochemistry of cell death. One way of subverting resistance is by the use of drugs whose mechanism of action is novel so that the tumour is challenged to devise a new defense. Here, we are attempting to develop synthetic analogues of a class of naturally- occurring antitumour antibiotic whose mechanism of action is unusual but which has not been exploited by medicinal chemists because of the difficulty of the chemistry involved. These antibiotics work by binding to DNA and inhibiting the first step in the process whereby genes are turned into proteins. We have designed compounds that are chemically accessible that our preliminary work suggests mimic the DNA-binding and biological properties of the natural antibiotics. The proposed work will enable us to evaluate whether this new class of agent has experimental antitumour activity, particularly amongst drug-resistant tumours.Read moreRead less
Development Of DNA Phosphate Crosslinking Agents As Potential Anticancer Drugs
Funder
National Health and Medical Research Council
Funding Amount
$392,545.00
Summary
The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar ....The principal difficulty in the treatment of the common solid tumours that cause the majority of cancer deaths is the problem of drug resistance. For example, many patients with cancer of the lung, breast or colon respond well to drug treatment with their tumours initially regressing, only to return later in an aggressive drug-resistant form. In this event, the inevitable outcome is that the tumour grows through drug treatment and the patient eventually succumbs and dies. This is also a familiar scenario in the treatment of adults with leukaemias and non-Hodgkins lymphomas. The underlying cause of drug resistance is the genetic instability of cancer cells which results in tumours that are heterogeneous, making it almost inevitable that a cancer cell will arise that is resistant to treatment. There are many mechanisms of resistance, some of which are peculiar to particular drug types, some are permeability barriers and some involve genetic deregulation of the biochemistry of cell death. Alkylating agents are one of the most important classes of anticancer drug. They bind irreversibly to the bases in DNA and weld the two strands of the double helix together. This cross-link is a powerful block to DNA replication and leads to the death of cancer cells by the process of programmed cell death. Cancer cells generally become resistant to alkylating agents by invoking repair mechanisms that remove the drug from the DNA bases, a response which breaks the cross-link and returns the DNA to its normal state. In this project, we are developing a new type of alkylating agent that reacts not with the DNA bases but with the phosphate groups of the DNA backbone. By this means the strands of DNA can again be cross-linked but now the linkage is between parts of the DNA that cancer cells cannot separate. In this way, we hope to be able to devise new drugs that are resistant to the normal mechanisms of DNA repair so that they will be active against drug-resistant tumours.Read moreRead less