A minimum core outcome dataset for the reporting of preclinical chemotherapeutic drug studies: Lessons learned from multiple discordant methodologies in the setting of colorectal cancer.

In vivo studies in animal models are critical tools necessary to study the fundamental complexity of carcinogenesis. A constant strive to improve animal models in cancer exists, especially those investigating the use of chemotherapeutic effectiveness. In the present systematic review, colorectal cancer (CRC) is used as an example to highlight and critically evaluate the range of reporting strategies used when investigating chemotherapeutic agents in the preclinical setting. A systematic review examining the methodology and reporting of preclinical chemotherapeutic drug studies using CRC murine models was conducted. A total of 45 studies were included in this systematic review. The literature was found to be highly heterogeneous with various cell lines, animal strains, animal ages and chemotherapeutic compounds/regimens tested, proving difficult to compare outcomes between similar studies or indeed gain any significant insight into which chemotherapeutic regimen caused adverse events. From this analysis we propose a minimum core outcome dataset that could be regarded as a standardised way of reporting results from in vivo experimentation.

A 19S proteasomal subunit cooperates with an ERK MAPK-regulated degron to regulate accumulation of Fra-1 in tumour cells.

Fos-related antigen-1 (Fra-1) is a member of the Activator Protein-1 (AP-1) transcription factor superfamily that is overexpressed in a variety of cancers, including colon, breast, lung, bladder and brain. High Fra-1 levels are associated with enhanced cell proliferation, survival, migration and invasion. Despite its frequent overexpression, the molecular mechanisms that regulate the accumulation of Fra-1 proteins in tumour cells are not well understood. Here, we show that turnover of Fra-1, which does not require ubiquitylation, is cooperatively regulated by two distinct mechanisms-association with the 19S proteasomal subunit, TBP-1, and by a C-terminal degron, which acts independently of TBP-1, but is regulated by RAS-ERK (extracellular signal-regulated kinase) signalling. TBP-1 depletion stabilized Fra-1 and further increased its levels in tumour cells expressing RAS-ERK pathway oncogenes. These effects correlated with increased AP-1 transcriptional activity. We suggest that during Fra-1 degradation, association with TBP-1 provides a mechanism for ubiquitin-independent proteasomal recognition, while the C terminus of the protein regulates its subsequent proteolytic processing.

Regulation of p53 expression, phosphorylation and subcellular localization by a G-protein-coupled receptor.

G-protein-coupled receptors (GPCRs) have been extremely successful drug targets for a multitude of diseases from heart failure to depression. This superfamily of cell surface receptors have not, however, been widely considered as a viable target in cancer treatment. In this study we show that a classical G(q/11)-coupled GPCR, the M(3)-muscarinic receptor, was able to regulate apoptosis through receptors that are endogenously expressed in the human neuroblastoma cell line, SH-SY5Y, and when ectopically expressed in Chinese hamster ovary (CHO) cells. Stimulation of the M(3)-muscarinic receptor was shown to inhibit the ability of the DNA-damaging chemotherapeutic agent, etoposide, from mediating apoptosis. This protective response in CHO cells correlated with the ability of the receptor to regulate the expression levels of p53. In contrast, stimulation of endogenous muscarinic receptors in SH-SY5Y cells did not regulate p53 expression but rather was able to inhibit p53 translocation to the mitochondria and p53 phosphorylation at serine 15 and 37. This study suggests the possibility that a GPCR can regulate the apoptotic properties of a chemotherapeutic DNA-damaging agent by regulating the expression, subcellular trafficking and modification of p53 in a manner that is, in part, dependent on the cell type.