E. coli NfsA: an alternative nitroreductase for prodrug activation gene therapy in combination with CB1954

Prodrug activation gene therapy is a developing approach to cancer treatment, whereby prodrug-activating enzymes are expressed in tumour cells. After administration of a non-toxic prodrug, its conversion to cytotoxic metabolites directly kills tumour cells expressing the activating enzyme, whereas the local spread of activated metabolites can kill nearby cells lacking the enzyme (bystander cell killing). One promising combination that has entered clinical trials uses the nitroreductase NfsB from Escherichia coli to activate the prodrug, CB1954, to a potent bifunctional alkylating agent. NfsA, the major E. coli nitroreductase, has greater activity with nitrofuran antibiotics, but it has not been compared in the past with NfsB for the activation of CB1954. We show superior in vitro kinetics of CB1954 activation by NfsA using the NADPH cofactor, and show that the expression of NfsA in bacterial or human cells results in a 3.5- to 8-fold greater sensitivity to CB1954, relative to NfsB. Although NfsB reduces either the 2-NO2 or 4-NO2 positions of CB1954 in an equimolar ratio, we show that NfsA preferentially reduces the 2-NO2 group, which leads to a greater bystander effect with cells expressing NfsA than with NfsB. NfsA is also more effective than NfsB for cell sensitisation to nitrofurans and to a selection of alternative, dinitrobenzamide mustard (DNBM) prodrugs

Study Protocol - Accurate assessment of kidney function in Indigenous Australians: aims and methods of the eGFR Study

Background: There is an overwhelming burden of cardiovascular disease, type 2 diabetes and chronic kidney disease among Indigenous Australians. In this high risk population, it is vital that we are able to measure accurately kidney function. Glomerular filtration rate is the best overall marker of kidney function. However, differences in body build and body composition between Indigenous and non-Indigenous Australians suggest that creatinine-based estimates of glomerular filtration rate derived for European populations may not be appropriate for Indigenous Australians. The burden of kidney disease is borne disproportionately by Indigenous Australians in central and northern Australia, and there is significant heterogeneity in body build and composition within and amongst these groups. This heterogeneity might differentially affect the accuracy of estimation of glomerular filtration rate between different Indigenous groups. By assessing kidney function in Indigenous Australians from Northern Queensland, Northern Territory and Western Australia, we aim to determine a validated and practical measure of glomerular filtration rate suitable for use in all Indigenous Australians

PEG−peptide conjugates

The remarkable diversity of the self-assembly behavior of PEG−peptides is reviewed, including self-assemblies formed by PEG−peptides with β-sheet and α-helical (coiled-coil) peptide sequences. The modes of self-assembly in solution and in the solid state are discussed. Additionally, applications in bionanotechnology and synthetic materials science are summarized

Trastuzumab emtansine, an antibody-drug conjugate for the treatment of HER2+metastatic breast cancer

Roche Holding AG, and its subsidiaries Genentech Inc and Chugai Pharmaceutical Co Ltd, are developing trastuzumab emtansine (trastuzumab-DM1) for the treatment of HER2+ metastatic breast cancer. Trastuzumab emtansine is a tumor-activated prodrug resulting from the conjugation of the humanized anti-HER2 mAb trastuzumab, which has been used in the treatment of breast cancer for over 10 years, with ImmunoGen Inc's cytotoxic and antimitotic maytansine derivative DM1. The maytansinoids bind microtubules in a manner similar to the vinca alkaloids; however, maytansinoids have been recognized to be 20- to 100-fold more potent at blocking mitosis. Nevertheless, the use of these compounds as single agents is limited by toxicity. By conjugating DM1 with trastuzumab, the delivery of the cytotoxic agent to target cells is more specific and reduces the safety concerns. In preclinical studies, the conjugation was effective in breast cancer cell lines resistant to trastuzumab, and demonstrated complete tumor regression in SCID mice bearing KPL4 breast cancer xenografts. Clinically, trastuzumab emtansine exhibited efficacy in patients with HER2+ metastatic breast cancer who had progressed on previous chemotherapy regimens or with trastuzumab therapy. Furthermore, preclinical studies have reported that trastuzumab emtansine potentiates the effect of a number of chemotherapeutic agents (including carboplatin, 5-fluorouracil and docetaxel), other antibodies, receptor tyrosine kinase inhibitors and PI3K inhibitors, and many of these combinations are set to be tested in humans. Trastuzumab emtansine offers an exciting new option for the treatment of patients with refractory, metastatic breast cancer

Introduction to the background, principles, and state of the art in suicide gene therapy.

Este artículo investiga el problema de las condiciones de posibilidad de los lazos sociales en el caso de sujetos psicóticos. Desde el marco teórico del psicoanálisis lacaniano interroga la tesis del “fuera de discurso” de las psicosis. Desde un punto de vista metodológico, procede por construcción y análisis del caso del bailarín Vaslav Nijinsky a partir de sus cuadernos autobiográficos, de su biografía y de distintos testimonios. El análisis de este caso nos permite concluir que el armado de un cuerpo a través de la danza fue posibilitado por la función del “nombrar para” que Lacan describe en 1974 y que sustituye al funcionamiento metafórico del Nombre-del- Padre. La constitución de un cuerpo danzante y su ejercicio actuaron en Nijinsky como causa del deseo del poderoso representante Diaghilev, quien lo transformó en una estrella, ovacionada para el público.Este artigo investiga o problema das condições de possibilidade de laços sociais no caso de sujeitos psicóticos. A partir do referencial teórico da psicanálise lacaniana, questiona a tese “fora do discurso” das psicoses. Do ponto de vista metodológico, procede pela construção e análise do caso do bailarino Vaslav Nijinsky a partir de seus cadernos autobiográficos, de sua biografia e de vários testemunhos. A análise desse caso nos permite concluir que a montagem de um corpo através da dança foi possibilitada pela função de “nomear para”, que Lacan descreve em 1974 e que substitui o funcionamento metafórico do Nome-do-Pai. A constituição de um corpo dançante e seu exercício atuou em Nijinsky como causa de desejo do poderoso representante Diaghilev, que o transformou em uma estrela, aplaudida pelo público.This paper investigates the problem of social bonds possibility conditions in the case of psychotics. Based on the theoretical framework of Lacanian psychoanalysis, it questions the “out of discourse” of psychoses. From the methodological point of view, it undertakes the construction and analysis of the case of the ballet dancer Vaslav Nijinsky, based on his autobiographical notebooks, his biography and various testimonies. The analysis of this case allows us to conclude that the assembly of a body through dance was allowed by the function of “naming for” which Lacan describes in 1974, and which replaces the metaphorical functioning of the Name-ofthe- Father. The constitution of a dancing body and its exercise acted in Nijinsky as the cause of desire of the powerful representative Diaghilev, who transformed him into a star, applauded by the public.Facultad de Psicologí

Significant differences in biological parameters between prodrugs cleavable by carboxypeptidase G2 that generate 3,5-difluoro-phenol and -aniline nitrogen mustards in gene-directed enzyme prodrug therapy systems.

Nine new nitrogen mustard compounds derived from 2,6-difluoro-4-hydroxy- (3a-e) and 2,6-difluoro-4-amino- (4a-d) aniline were synthesized as potential prodrugs. They were designed to be activated to their corresponding 3,5-difluorophenol and -aniline (4)-nitrogen mustards by the enzyme carboxypeptidase G2 (CPG2) in gene-directed enzyme prodrug therapy (GDEPT) models. The compounds were tested for cytotoxicity in the MDA MB-361 breast adenocarcinoma. The cell line was engineered to express stably either CPG2 tethered to the cell surface stCPG2-(Q)3 or beta-galactosidase (beta-Gal) as control. The cytotoxicity differentials were calculated between CPG 2-expressing and -nonexpressing cells and yielded different results for the two series of prodrugs despite their structural similarities. While the phenol compounds are ineffective as prodrugs, their aniline counterparts exhibit outstanding activity in the tumor cell lines expressing CPG2. [3,5-Difluoro-4-[bis(2-chloroethyl)amino]phenyl]carbamoyl-l-glutamic acid gave a differential of >227 in MDA MB361 cells as compared with 19 exhibited by 4-[(2-chloroethyl)(2-mesyloxyethyl)amino]benzoyl-l-glutamic acid, 1a, which has been in clinical trials