Stabilization of the hypoxia-inducible factor-1alpha (HIF-1alpha) transcription complex, caused by intratumoural hypoxia, promotes tumour progression and metastasis, leading to treatment failure and mortality in different types of human cancers. The transcription factor TWIST is a master regulator of gastrulation and mesoderm-specification and was implicated recently as an essential mediator of cancer metastasis. Notably, HIF-1alpha- and TWIST-null mice show similarities in their phenotypes. Here, we have shown that hypoxia or overexpression of HIF-1alpha promotes epithelial-mesenchymal transition (EMT) and metastastic phenotypes. We also found that HIF-1 regulates the expression of TWIST by binding directly to the hypoxia-response element (HRE) in the TWIST proximal promoter. However, siRNA-mediated repression of TWIST in HIF-1alpha-overexpressing or hypoxic cells reversed EMT and metastastic phenotypes. Co-expression of HIF-1alpha, TWIST and Snail in primary tumours of patients with head and neck cancers correlated with metastasis and the worst prognosis. These results provide evidence of a key signalling pathway involving HIF-1alpha and TWIST that promotes metastasis in response to intratumoural hypoxia.

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LEARNING OBJECTIVESAfter completing this course, the reader will be able to:1. Identify the clinical features of oxaliplatin-induced neuropathy.2. Discuss the current approaches for managing chemotherapy-induced neuropathy.3. Explain the rationale for using glutamine in preventing oxaliplatin-induced neuropathy.Access and take the CME test online and receive 1 AMA PRA Category 1 Credit ™ at CME.TheOncologist.com CME CME ABSTRACTOxaliplatin is effective in the treatment of metastatic colorectal cancer (MCRC) patients; however, severe neurotoxicity develops frequently. To assess the efficacy of oral glutamine for preventing neuropathy induced by oxaliplatin, a pilot study was performed. A total of 86 patients with MCRC treated at Taipei Veterans General Hospital were enrolled. Oxaliplatin (85 mg/m 2 , days 1 and 15) plus weekly bolus 5-fluorouracil (5-FU; 500 mg/m 2 ) and folinic acid (FA; 20 mg/m 2 ) on days 1, 8, and 15 were given every 28 days as firstline treatment. Patients were randomized to receive (glutamine group; n ‫؍‬ 42) or not receive (control group; n ‫؍‬ 44) glutamine (15 g twice a day for seven consecutive days every 2 weeks starting on the day of oxaliplatin infusion). Efficacy of chemotherapy, neurological toxicity, and electrophysiological alterations were assessed. A lower percentage of grade 1-2 peripheral neuropathy was observed in the glutamine group (16.7% versus 38.6%) after two cycles of treatment, and a significantly lower incidence of grade 3-4 neuropathy was noted in the glutamine group after four cycles (4.8% versus 18.2%) and six cycles (11.9% versus 31.8%). By adding glutamine, interference with activities of daily living was lower (16.7% versus 40.9%), and need for oxaliplatin dose reduction was lower (7.1% versus 27.3%). There were no significant between-group differences in response to chemotherapy (52.4% versus 47.8%), electrophysiological abnormalities, grade 3-4 non-neurological toxicities (26.2% versus 22.8%), or survival. These data indi- Disclosure of potential conflicts of interest is found at the end of this article.

Several reports recently found that patients with B cell non-Hodgkin's lymphoma (NHL) had a higher carrier rate of hepatitis B surface antigen (HBsAg). The current study aimed to examine the hepatitis B virus (HBV) infection status of NHL patients in Taiwan, an HBV-endemic area. Serum HBV and serum hepatitis C virus were measured in 471 NHL patients and 1,013 non-lymphoma cancer patients enrolled between February 2000 and March 2007. Furthermore, nested polymerase chain reaction of HBV-DNA was used to examine the sera from selected patients in these two populations and healthy volunteers for the presence of occult HBV infection. The infection rates (as indicated by the rates of HBsAg and occult HBV) were compared between different groups. There was a higher incidence of HBV infection in B cell NHL patients (23.5%), especially patients with diffuse large B lymphoma, than solid tumor patients (15.6%, P = 0.001). Among HbsAg-negative patients, those with B cell NHL had a higher prevalence of occult HBV infection (6%) than those with non-lymphoma solid tumors and healthy volunteers, 0% and 0.9%, respectively (P = 0.005). B cell NHL patients, even HBsAg-negative B cell NHL patients, but not T cell NHL patients, have a higher incidence of HBV infection than patients with solid tumors. Our findings support the etiologic role of HBV infection in B cell NHL.

Purpose: Head and neck squamous cell carcinoma (HNSCC) represents the sixth most frequent type of cancer worldwide. However, the molecular genetic alterations underlying its malignant behavior and progression are little known. We showed previously that c-MYC directly activates the expression of the DNA double-strand break repair gene NBS1, and NBS1overexpression contributes to transformation. Here, we investigate the role of NBS1overexpression in HNSCC. Experimental Design: Immunohistochemistry analysis of NBS1 expression was done in 81 locally advanced HNSCC patients. Real-time PCR andWestern blot analysis were used to confirm immunohistochemistry results. Human hypopharyngeal cancer cell lines (FADU) with overexpressing NBS1 (FADUNBS) or inducible short interference RNA to repress endogenous NBS1 (FADUNBSi) were generated by stable transfection. Soft agar clonogenicity assay was used to determine the transformation activity. Western blot analysis and phosphatidylinositol 3-kinase (PI3K) assay were done to evaluate the signaling pathways that were involved. Results: NBS1 overexpression was identified in 45% of advanced HNSCC patients. It was an independent marker of poor prognosis. NBS1expression levels correlated with the transformation activity of FADU clones and also correlated with the phosphorylation levels of Akt and its downstream target mammalian target of rapamycin (mTOR). PI3K activity was increased in NBS1-overexpressing FADU clones. NBS1 overexpression also correlated with increased Akt phosphorylation levels in tumor samples. Conclusions: Increased NBS1expression is a significant prognostic marker of advanced HNSCC, and the underlying mechanism may involve the activation of the PI3K/Akt pathway.