Timothy Andrews

UHRF1 regulation of the Keap1–Nrf2 pathway in pancreatic cancer contributes to oncogenesis

The cellular defence protein Nrf2 is a mediator of oncogenesis in pancreatic ductal adenocarcinoma (PDAC) and other cancers. However, the control of Nrf2 expression and activity in cancer is not fully understood. We previously reported the absence of Keap1, a pivotal regulator of Nrf2, in ∼70% of PDAC cases. Here we describe a novel mechanism whereby the epigenetic regulator UHRF1 suppresses Keap1 protein levels. UHRF1 expression was observed in 20% (5 of 25) of benign pancreatic ducts compared to 86% (114 of 132) of pancreatic tumours, and an inverse relationship between UHRF1 and Keap1 levels in PDAC tumours (n = 124) was apparent (p = 0.002). We also provide evidence that UHRF1‐mediated regulation of the Nrf2 pathway contributes to the aggressive behaviour of PDAC. Depletion of UHRF1 from PDAC cells decreased growth and enhanced apoptosis and cell cycle arrest. UHRF1 depletion also led to reduced levels of Nrf2‐regulated downstream proteins and was accompanied by heightened oxidative stress, in the form of lower glutathione levels and increased reactive oxygen species. Concomitant depletion of Keap1 and UHRF1 restored Nrf2 levels and reversed cell cycle arrest and the increase in reactive oxygen species. Mechanistically, depletion of UHRF1 reduced global and tumour suppressor promoter methylation in pancreatic cancer cell lines, and KEAP1 gene promoter methylation was reduced in one of three cell lines examined. Thus, methylation of the KEAP1 gene promoter may contribute to the suppression of Keap1 protein levels by UHRF1, although our data suggest that additional mechanisms need to be explored. Finally, we demonstrate that K‐Ras drives UHRF1 expression, establishing a novel link between this oncogene and Nrf2‐mediated cellular protection. Since UHRF1 over‐expression occurs in other cancers, its ability to regulate the Keap1–Nrf2 pathway may be critically important to the malignant behaviour of these cancers.

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

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.

Helicobacter pylori, HIV and Gastric Hypochlorhydria in the Malawian Population

Background HIV and Helicobacter pylori are common chronic infections in sub-Saharan Africa. Both conditions can predispose to gastric hypochlorhydria that may be a risk factor for enteric infections and reduced drug absorption. We have investigated to what extent HIV and H. pylori infections are associated with hypochlorhydria in a Malawian cohort of patients undergoing endoscopy. Methods 104 sequential symptomatic adults referred for gastroscopy at Queen Elizabeth Central Hospital, Blantyre, Malawi, had blood taken for rapid HIV testing and fasting serum gastrin analysis. Gastric fluid was aspirated for pH testing, and gastric biopsies were taken. Results After 9/104 HIV-infected patients who were already established on anti-retroviral therapy were excluded, 17/95 (25.0%) were seropositive for untreated HIV, and 68/95 (71.6%) patients were H. pylori positive by histology. Hypochlorhydria (fasting gastric pH>4.0) was present in 55.8% (53/95) of patients. H. pylori infection was significantly associated with hypochlorhydria (OR 2.91, [1.02-7.75], p=0.046). While single infection with HIV was not significantly independently associated with hypochlorhydria. H. pylori and HIV co-infection was more strongly associated with hypochlorhydria (OR 6.25, [1.33-29.43], p=0.020) than either infection alone, suggesting an additive effect of co-infection. HIV infection was associated with higher serum gastrin levels (91.3pM vs. 53.1pM, p=0.040), while H. pylori infection was not (63.1pM vs. 55.1pM, p=0.610). Irrespective of H. pylori and HIV status, most patients (>90%) exhibited pangastritis. Only three patients had histological evidence of gastric atrophy, of which only one was HIV-infected. Conclusion H. pylori infection was associated with fasting hypochlorhydria, while HIV was not independently associated. HIV and H. pylori co-infection, however, was more strongly associated with hypochlorhydria than H. pylori infection alone. The mechanism of this apparent additive effect between HIV and H. pylori remains unclear, but appears to be related to chronic pangastritis rather than gastric atrophy, and associated with hypergastrinaemia in HIV-infected individuals.

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-&mgr;m-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.

Schistosomiasis japonicum diagnosed on liver biopsy in a patient with hepatitis B co-infection: a case report

IntroductionChronic hepatitis B virus and schistosomiasis are independently associated with significant mortality and morbidity worldwide. Despite much geographic overlap between these conditions and no reason why co-infection should not exist, we present what is, to the best of our knowledge, the first published report of a proven histological diagnosis of hepatic Schistosomiasis japonicum and chronic hepatitis B co-infection. A single case of hepatitis B and hepatic Schistosomiasis mansoni diagnosed by liver biopsy has previously been reported in the literature.Case presentationA 38-year-old Chinese man with known chronic hepatitis B virus infection presented with malaise, nausea and headache. Blood tests revealed increased transaminases and serology in keeping with hepatitis B virus e-antigen seroconversion. A liver biopsy was performed because some investigations, particularly transient elastography, suggested cirrhosis. Two schistosome ova were seen on liver histology, identified as S. japonicum, probably acquired in China as a youth. His peripheral eosinophil count was normal, schistosomal serology and stool microscopy for ova, cysts and parasites were negative.ConclusionHepatic schistosomiasis co-infection should be considered in patients with hepatitis B virus infection who are from countries endemic for schistosomiasis. Screening for schistosomiasis using a peripheral eosinophil count, schistosomal serology and stool microscopy may be negative despite infection, therefore presumptive treatment could be considered. Transient elastography should not be used to assess liver fibrosis during acute flares of viral hepatitis because readings are falsely elevated. The impact of hepatic schistosomiasis on the sensitivity and specificity of transient elastography measurement for the assessment of hepatitis B is as yet unknown.

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.

Is microscopic examination of hysterectomy specimens removed for clinically benign disease necessary

The likelihood of finding significant pathology in a hysterectomy specimen undertaken for clinically benign disease is low. Some data indicate that microscopic examination of these specimens may be abandoned. While this approach may seem attractive, the authors believe that there are a number of practical and clinical governance issues associated with this. Instead a pragmatic approach is advocated, with two tissue blocks (cervix and endomyometrium) being adequate in most cases.

Short article: Successful faecal coliform sensitivity-based oral ertapenem therapy for chronic antibiotic-refractory pouchitis: a case series.

Pouchitis is a common complication of restorative proctocolectomy for ulcerative colitis, and a proportion of patients develop a refractory course. The treatment of chronic antibiotic-refractory pouchitis (CARP) is challenging, and treatment failure is often a cause of pouch excision. We report on a series of three patients with CARP who were treated with oral ertapenem following faecal coliform sensitivity testing. There was an improvement in the pouchitis disease activity index in all three patients [pretreatment pouch disease activity index, median 13 (range: 10–14); post-treatment pouch disease activity index, median 1 (range: 1–3)]. Identification of faecal coliform sensitivity and treatment with oral ertapenem might be helpful in patients with CARP.

PWE-189 Helicobacter Pylori, HIV and Gastric Hypochlorhydria in the malawian population

Introduction HIV and Helicobacter pylori are common chronic infections in sub-Saharan Africa. Both conditions can predispose to gastric hypochlorhydria that may be a risk factor for enteric infections and reduced drug absorption. We have investigated to what extent HIV and H. pylori infections are associated with hypochlorhydria in a Malawian cohort of patients undergoing endoscopy. Method 104 sequential symptomatic adults referred for gastroscopy at Queen Elizabeth Central Hospital, Blantyre, Malawi, had blood taken for rapid HIV testing and fasting serum gastrin analysis. Gastric fluid was aspirated for pH testing, and gastric biopsies were taken. Results After 9/104 HIV-infected patients who were already established on antiretroviral therapy were excluded, 17/95 (25.0%) were seropositive for untreated HIV, and 68/95 (71.6%) patients were H. pylori positive by histology. Hypochlorhydria (fasting gastric pH >4.0) was present in 55.8% (53/95) of patients. H. pylori infection was significantly associated with hypochlorhydria (OR 2.91, [1.02–7.75], p = 0.046). While single infection with HIV was not significantly independently associated with hypochlorhydria. H. pylori and HIV co-infection was more strongly associated with hypochlorhydria (OR 6.25, [1.33–29.43], p = 0.020) than either infection alone, suggesting an additive effect of co-infection. HIV infection was associated with higher serum gastrin levels (91.3pM vs. 53.1pM, p = 0.040), while H. pylori infection was not (63.1pM vs. 55.1pM, p = 0.610). Irrespective of H. pylori and HIV status, most patients (>90%) exhibited pangastritis. Only three patients had histological evidence of gastric atrophy, of which only one was HIV-infected. Conclusion H. pylori infection was associated with fasting hypochlorhydria, while HIV was not independently associated. HIV and H. pylori co-infection, however, was more strongly associated with hypochlorhydria than H. pylori infection alone. The mechanism of this apparent additive effect between HIV and H. pylori remains unclear, but appears to be related to chronic pangastritis rather than gastric atrophy, and associated with hypergastrinaemia in HIV-infected individuals. Disclosure of interest None Declared.