Validation of genetic classifiers derived from mouse and human tumors to identify molecular subtypes of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer death in the United States. Standard treatment for advanced-stage CRC for decades has included 5-fluorouracil-based chemotherapy. More recently, targeted therapies for metastatic CRC are being used based on the individual cancer's molecular profile. In the past few years, several different molecular subtype schemes for human CRC have been developed. The molecular subtypes can be distinguished by gene expression signatures and have the potential to be used to guide treatment decisions. However, many subtyping classification methods were developed using mRNA expression levels of hundreds to thousands of genes, making them impractical for clinical use. In this study, we assessed whether an immunohistochemical approach could be used for molecular subtyping of CRCs. We validated two previously published, independent sets of immunohistochemistry classifiers and modified the published methods to improve the accuracy of the scoring methods. In addition, we evaluated whether protein and genetic signatures identified originally in the mouse were linked to clinical outcomes of patients with CRC. We found that low DDAH1 or low GAL3ST2 protein levels in human CRCs correlate with poor patient outcomes. The results of this study have the potential to impact methods for determining the prognosis and therapy selection for patients with CRC.

Tumor aggressiveness is independent of radiation quality in murine hepatocellular carcinoma and mammary tumor models

PURPOSE

Estimating cancer risk associated with interplanetary space travel is complicated. Human exposure data to high atomic number, high-energy (HZE) radiation is lacking, so data from low linear energy transfer (low-LET) γ-ray radiation is used in risk models, with the assumption that HZE and γ-ray radiation have comparable biological effects. This assumption has been challenged by reports indicating that HZE radiation might produce more aggressive tumors. The goal of this research is to test whether high-LET HZE radiation induced tumors are more aggressive.

MATERIALS AND METHODS

Murine models of mammary and liver cancer were used to compare the impact of exposure to 0.2Gy of 300MeV/n silicon ions, 3 Gy of γ-rays or no radiation. Numerous measures of tumor aggressiveness were assessed.

RESULTS

For the mammary cancer models, there was no significant change in the tumor latency or metastasis in silicon-irradiated mice compared to controls. For the liver cancer models, we observed an increase in tumor incidence but not tumor aggressiveness in irradiated mice.

CONCLUSION

Tumors in the HZE-irradiated mice were not more aggressive than those arising from exposure to low-LET γ-rays or spontaneously. Thus, enhanced aggressiveness does not appear to be a uniform characteristic of all tumors in HZE-irradiated animals.

Which patients see a rheumatologist? SWRACR (South Western Regional Advisory Committee on Rheumatology)

Rheumatology outpatient consultations were recorded throughout the South Western Regional Health Authority for one month. Of 2987 consultations (equivalent to 32,600 annually), 630 (21%) were new referrals who waited 60 days (mode) before their consultation. Rheumatoid arthritis and polyarthritis accounted for 43% of new referrals and 75% of follow-up patients. For these categories, 6.5 follow-up patients were seen for each new referral, but this ratio varied from 3.7 to 11.7. Other diagnoses also had variable patterns of follow-up but because they represented only a small proportion they were less relevant to overall service provision and resource consumption. These data not only outline current outpatient working patterns but also indicate areas of further investigation which might elucidate methods of providing good patient care and appropriate use of resources.