Pharmacological Activation of Nrf2 Enhances Functional Liver Regeneration.

BACKGROUND AND AIMS: The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates an array of cytoprotective genes, yet studies in transgenic mice have led to conflicting reports on its role in liver regeneration. We aimed to test the hypothesis that pharmacological activation of Nrf2 would enhance liver regeneration. APPROACH AND RESULTS: Wild-type and Nrf2 null mice were administered bardoxolone methyl (CDDO-Me), a potent activator of Nrf2 that has entered clinical development, and then subjected to two-thirds partial hepatectomy. Using translational noninvasive imaging techniques, CDDO-Me was shown to enhance the rate of restoration of liver volume (MRI) and improve liver function (multispectral optoacoustic imaging of indocyanine green clearance) in wild-type, but not Nrf2 null, mice following partial hepatectomy. Using immunofluorescence imaging and whole transcriptome analysis, these effects were found to be associated with an increase in hepatocyte hypertrophy and proliferation, the suppression of immune and inflammatory signals, and metabolic adaptation in the remnant liver tissue. Similar processes were modulated following exposure of primary human hepatocytes to CDDO-Me, highlighting the potential relevance of our findings to patients. CONCLUSIONS: Our results indicate that pharmacological activation of Nrf2 is a promising strategy for enhancing functional liver regeneration. Such an approach could therefore aid the recovery of patients undergoing liver surgery and support the treatment of acute and chronic liver disease.

Prognostic value of hypoxia-associated markers in advanced larynx and hypopharynx squamous cell carcinoma.

OBJECTIVES/HYPOTHESIS: To determine the prognostic value of hypoxia-associated markers carbonic anhydrase-9 (CA-9) and hypoxia-inducible factor-1α (HIF-1α) in advanced larynx and hypopharynx squamous cell carcinoma (SCCa) treated by organ preservation strategies. STUDY DESIGN: Retrospective cohort study. METHODS: Pretreatment CA-9 and HIF-1α expression, clinicopathologic data, and tumor volume were analyzed in a series of 114 patients with T3-4 SCCa larynx or hypopharynx treated by (chemo)radiation. RESULTS: Adverse prognostic factors for locoregional control were T4 classification (P = 0.008), and for disease-specific survival were CA-9 positivity (P = 0.039), T4 classification (P = 0.001), larger tumor volume (P = 0.004), N1-3 classification (P = 0.002), and pretreatment hemoglobin < 13.0 g/dl (P = 0.014). With increasing CA-9 expression, there was a trend to increasing tumor recurrence (P trend = 0.009) and decreasing survival (P trend = 0.002). On multivariate analysis, independent variables were T4 classification (hazard ratio [HR] 13.54, P = 0.01) for locoregional failure, and CA-9 positivity (HR = 8.02, P = 0.042) and higher tumor volume (HR = 3.33, P = 0.007) for disease-specific mortality. CONCLUSION: This is the first study to look specifically at T3 and T4 SCCa larynx and hypopharynx for a relationship between hypoxia-associated marker expression and clinical outcome. Pretreatment immunohistochemical CA-9 expression is an adverse prognostic factor for disease-specific survival, indicating that CA-9 expression may confer a more aggressive tumor phenotype.

Histological evaluation of preoperative mediastinoscopy lymph node biopsies in non-small cell lung cancer.

INTRODUCTION: Despite the advent of PET scanning and endoscopic minimally invasive methods of sampling mediastinal lymph nodes, surgical assessment, particularly by mediastinoscopy, remains an important tool for staging non-small cell lung cancer. METHODS: We carried out a retrospective review of mediastinoscopic lymph node biopsies taken at The Royal Infirmary of Edinburgh between 1996 and 2006 and performed additional histological investigations on select cases. RESULTS: In total, 89/802 (11%) patients had a negative mediastinoscopy but final resection stage of N2/N3. Within this group, 41/89 (46%) patients had positive resection lymph nodes in stations potentially accessible to biopsy at mediastinoscopy. Of these, 30 (34%) patients had had the metastatic station sampled at mediastinoscopy. Further histopathological examination (multiple levels and pancytokeratin immunohistochemistry) of these original biopsies detected micrometastases in two cases, one of which, in retrospect, had been missed on the original section at the time of reporting. Isolated tumour cells were detected by immunohistochemistry in another two cases. CONCLUSIONS: Routine examination of additional levels and immunohistochemical staining of mediastinal lymph nodes biopsies is not required and would not improve the overall negative predictive value of the procedure.

Routinely obtained diagnostic material as a source of RNA for personalized medicine in lung cancer patients.

INTRODUCTION: Therapeutic approaches to lung cancer are evolving, with personalized therapy, based on "molecular analysis" of tumors being developed. Given that approximately 90% of patients will not undergo surgery for their disease, an ability to apply these tests to small samples obtained at the time of initial pathological diagnosis is desirable. Studies in this area have produced variable results, and the minimum area of tumor tissue required for analysis has not been defined. Furthermore, such assays have not been widely applied to cytology specimens, which may be the only source of diagnostic material in many cases. METHODS: Routinely processed biopsy and cytology specimens were microdissected to enrich for tumor cells, followed by RNA extraction using QIAGEN RNeasy kit and cDNA synthesis/reverse-transcriptase polymerase chain reaction for genes including beta-actin, ERCC-1, and RRM-1, according to standard laboratory protocols. Paired biopsy and resection specimens were similarly analyzed. RESULTS: As little as 1 mm² of tumor tissue, from a 10-µm-thick section, may be used to produce RNA suitable for analysis. RNA of adequate quality and quantity for analysis may be obtained from residual, routinely processed biopsy and cytology specimens. There is good correlation between the result obtained on the tumor biopsy specimen and paired blocks from the surgical resection with respect to clinical decision making. CONCLUSION: Routinely processed clinical diagnostic samples provide a suitable source of RNA for polymerase chain reaction-based molecular analyses, potentially providing personalized medicine to all lung cancer patients.