American Association for Cancer Research

February 1 Cancer Research Highlights

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Selected Articles from the February 1, 2006 Issue

The articles referenced in this Highlights section will be available online in HTML and PDF formats to all interested users at no charge until the next issue of Cancer Research is published. Click on the article title to view the complete article.

View the Table of Contents for the February 1 issue of Cancer Research.


Lung Oncogenesis Progresses via Independent Epigenetically Altered Pathways

Toyooka et al.

Page 1371

Genetic and epigenetic alterations are important mechanisms for tumorigenesis of lung cancer. Recently, mutation of the EGFR gene was demonstrated to be present in adenocarcinoma of the lung. Moreover, EGFR mutation showed a mutually exclusive pattern with K-RAS mutation, suggesting the presence of two independent pathways for the development of adenocarcinoma. Toyooka et al. examined the relationship between somatic mutation of EGFR and K-RAS genes and DNA methylation of several genes in 164 cases of lung adenocarcinoma to investigate the association among these alterations. Results indicate the clear difference in epigenetic alteration between EGFR- and K-RAS–mediated oncogenic pathways in lung cancer and suggest the specific interaction of genetic and epigenetic changes in tumorigenesis of lung adenocarcinoma.

 


Simulation Model Predicts Tumor Invasion in Marginal Environmental Conditions

Frieboes et al.
Page 1597

CAN 02-01-06 Frieboes 1597Computer simulations of a reaction-diffusion mathematical model and in vitro experiments predict that tumor morphology is a function of marginally stable environmental conditions. The authors propose that tumor morphogenesis in vivo may be a function of marginally stable environmental conditions caused by spatial variations in cell nutrients, oxygen, and growth factors, and that controlling these conditions by decreasing spatial gradients could benefit treatment outcomes. In contrast, they suggest current treatment, and especially antiangiogenic therapy, may trigger spatial heterogeneity (e.g., local hypoxia) thus causing invasive instability.


Small Molecule Inhibitor Curbs Breast Cancer Cell Growth

Konecny et al.
Page 1630

Lapatinib is a selective inhibitor of both the EGFR and HER2 tyrosine kinases. To explore its therapeutic potential for the treatment of breast cancer, Konecny et al. designed preclinical models which demonstrate that lapatinib has particular antitumor activity in HER2-overexpressing breast cancer cells. It retained its antitumor activity in cells resistant to trastuzumab, and synergistic drug interactions were observed when it was combined with a monoclonal antibody such as trastuzumab. These observations provide a biologic rational to test lapatinib as a single agent or in combination with trastuzumab in HER2-overexpressing breast cancer and in patients with clinical resistance to trastuzumab.


Liver Cancer Initiated via Hyperinsulinism, Altered Ras-Raf-MAPK Pathway

Dombrowski et al.
Page 1833

CAN 02-01-05 Dombrowski 1833Combined hyperinsulinism and hyperglycemia induces hepatocarcinogenesis after intrahepatic low-number transplantation of pancreatic islets in streptozotocin-diabetic Lewis rats. However, streptozotocin is genotoxic and may have contributed to the carcinogenic process. Dombrowski et al. have shown that hepatocarcinogenesis can also be initiated in spontaneously auto-immune diabetic rats, unequivocally excluding streptozotocin as a significant contributor. They demonstrated that insulin-induced, long-term, adaptive metabolic alterations of hepatocytes, including altered enzyme activities in the carbohydrate metabolism and altered signaling via the Ras-Raf-MAPK pathway and the IGF-1 axis, can be the starting point of a hepatocarcinogenic process.


Mass Spectrometry Useful to Depict Proteomic Signature of Radiotherapy

Ménard et al.
Page 1844

CAN 02-01-06 Konecny 1630Ménard et al. sought to discover clinical biomarkers of radiation exposure using proteomic profiling strategies. High-throughput SELDI-TOF mass spectrometry generated high-resolution proteomic profiles of unfractionated serum samples from 68 patients before and during a course of radiotherapy. Supervised classification techniques accurately distinguished unexposed from radiation-exposed samples, and high from low dose-volume levels of exposure. Mass spectrometry of pooled sera identified 23 protein fragments/peptides uniquely detected in the radiation exposure group. Proteomic analysis for the discovery of clinical biomarkers of radiation exposure warrants further study, and may have broad implication in cancer care and population exposures to radiation.