Laboratory of Molecular Biology

About: Laboratory of Molecular Biology is a facility organization based out in Cambridge, Cambridgeshire, United Kingdom. It is known for research contribution in the topics: Gene & RNA. The organization has 19395 authors who have published 24236 publications receiving 2101480 citations.

Immunotoxin Therapy of Cancer

Abstract: Rationally designed anticancer agents that target cell-surface antigens or receptors represent a promising approach for treating cancer patients. However, antibodies that bind these targets are often, by themselves, non-cytotoxic. By attaching potent toxins we can dramatically improve the clinical utility of some anti-tumour antibodies. Here we describe the construction and clinical utility of several recombinant immunotoxins; each of which is composed of antibody Fv fragments fused to powerful bacterial toxins. Results from clinical trials indicate that recombinant immunotoxins and similar agents that are designed to combine antibody selectivity with toxin cell-killing potency will be useful additions to cancer therapy.

Fancd2 counteracts the toxic effects of naturally produced aldehydes in mice

Abstract: Reactive aldehydes are common carcinogens. They are also by-products of several metabolic pathways and, without enzymatic catabolism, may accumulate and cause DNA damage. Ethanol, which is metabolised to acetaldehyde, is both carcinogenic and teratogenic in humans. Here we find that the Fanconi anaemia DNA repair pathway counteracts acetaldehyde-induced genotoxicity in mice. Our results show that the acetaldehyde-catabolising enzyme Aldh2 is essential for the development of Fancd2−/− embryos. Nevertheless, acetaldehyde-catabolism-competent mothers (Aldh2+/− ) can support the development of double-mutant (Aldh2−/−Fancd2−/− ) mice. However, these embryos are unusually sensitive to ethanol exposure in utero, and ethanol consumption by postnatal double-deficient mice rapidly precipitates bone marrow failure. Lastly, Aldh2−/−Fancd2−/− mice spontaneously develop acute leukaemia. Acetaldehyde-mediated DNA damage may critically contribute to the genesis of fetal alcohol syndrome in fetuses, as well as to abnormal development, haematopoietic failure and cancer predisposition in Fanconi anaemia patients. Individuals with Fanconi anaemia exhibit developmental defects, stem-cell failure and a strong predisposition to leukaemia. Cells derived from patients with Fanconi anaemia are susceptible to DNA damage caused by DNA crosslinking agents such as cisplatin and mitomycin C. These are cancer chemotherapeutics, so cells are not normally exposed to them, prompting the question: what is the natural source of DNA damage repaired by this pathway? Experiments with mice deficient in Fancd2 (one of several Fanconi anaemia genes) and Aldh2 (which encodes an enzyme that detoxifies aldehydes) suggest that acetaldehyde is an endogenous source of DNA damage in Fanconi anaemia, contributing to cancer predisposition and haematopoeitic failure. Intriguingly, these mouse models also suggest a possible mechanism for the damaging effects of fetal alcohol exposure during pregnancy.

Conformational thermostabilization of the β1-adrenergic receptor in a detergent-resistant form

Abstract: There are ≈350 non-odorant G protein-coupled receptors (GPCRs) encoded by the human genome, many of which are predicted to be potential therapeutic targets, but there are only two structures available to represent the whole of the family. We hypothesized that improving the detergent stability of these receptors and simultaneously locking them into one preferred conformation will greatly improve the chances of crystallization. We developed a generic strategy for the isolation of detergent-solubilized thermostable mutants of a GPCR, the β1-adrenergic receptor. The most stable mutant receptor, βAR-m23, contained six point mutations that led to an apparent Tm 21°C higher than the native protein, and, in the presence of bound antagonist, βAR-m23 was as stable as bovine rhodopsin. In addition, βAR-m23 was significantly more stable in a wide range of detergents ideal for crystallization and was preferentially in an antagonist conformation in the absence of ligand.