BackgroundNrf2 is a key transcriptional regulator of a battery of genes that facilitate phase II/III drug metabolism and defence against oxidative stress. Nrf2 is largely regulated by Keap1, which directs Nrf2 for proteasomal degradation. The Nrf2/Keap1 system is dysregulated in lung, head and neck, and breast cancers and this affects cellular proliferation and response to therapy. Here, we have investigated the integrity of the Nrf2/Keap1 system in pancreatic cancer.ResultsKeap1, Nrf2 and the Nrf2 target genes AKR1c1 and GCLC were detected in a panel of five pancreatic cancer cell lines. Mutation analysis of NRF2 exon 2 and KEAP1 exons 2-6 in these cell lines identified no mutations in NRF2 and only synonomous mutations in KEAP1. RNAi depletion of Nrf2 caused a decrease in the proliferation of Suit-2, MiaPaca-2 and FAMPAC cells and enhanced sensitivity to gemcitabine (Suit-2), 5-flurouracil (FAMPAC), cisplatin (Suit-2 and FAMPAC) and gamma radiation (Suit-2). The expression of Nrf2 and Keap1 was also analysed in pancreatic ductal adenocarcinomas (n = 66 and 57, respectively) and matching normal benign epithelium (n = 21 cases). Whilst no significant correlation was seen between the expression levels of Keap1 and Nrf2 in the tumors, interestingly, Nrf2 staining was significantly greater in the cytoplasm of tumors compared to benign ducts (P < 0.001).ConclusionsExpression of Nrf2 is up-regulated in pancreatic cancer cell lines and ductal adenocarcinomas. This may reflect a greater intrinsic capacity of these cells to respond to stress signals and resist chemotherapeutic interventions. Nrf2 also appears to support proliferation in certain pancreatic adenocarinomas. Therefore, strategies to pharmacologically manipulate the levels and/or activity of Nrf2 may have the potential to reduce pancreatic tumor growth, and increase sensitivity to therapeutics.

The rodent S100-related calcium-binding protein, S100A4 induces metastasis in non-metastatic rat and mouse benign mammary cells and co-operates with benign-tumour-inducing changes in two transgenic mouse models, to yield metastatic mammary tumours. Cotransfection of the human gene for S100A4 with pSV2neo into the benign rat mammary cell line, Rama 37, yielded cells which expressed a low level of the endogenous S100A4 mRNA, and either high or undetectable levels of human S100A4 mRNA. The cells which expressed a high level of human S100A4 mRNA induced metastasis in the benign rat mammary cell line Rama 37 in an in vivo assay, whereas the cells which expressed an undetectable level of human S100A4 did not induce any detectable metastases. The primary tumours arising from the S100A4-expressing cells contained high levels of immunocytochemically-detected S100A4 and this high level of S100A4 and the metastatic potential were maintained when cells from a metastasis were re-injected into syngeneic rats. The results show that the human S100A4 possesses metastasis-inducing capabilities.

Background:Extracapsular spread (ECS) in cervical lymph nodes is the single-most prognostic clinical variable in oral squamous cell carcinoma (OSCC), but diagnosis is possible only after histopathological examination. A promising biomarker in the primary tumour, alpha smooth muscle actin (SMA) has been shown to be highly prognostic, however, validated biomarkers to predict ECS prior to primary treatment are not yet available.Methods:In 102 OSCC cases, conventional imaging was compared with pTNM staging. SERPINE1, identified from expression microarray of primary tumours as a potential biomarker for ECS, was validated through mRNA expression, and by immunohistochemistry (IHC) on a tissue microarray from the same cohort. Similarly, expression of SMA was also compared with its association with ECS and survival. Expression was analysed separately in the tumour centre and advancing front; and prognostic capability determined using Kaplan–Meier survival analysis.Results:Immunohistochemistry indicated that both SERPINE1 and SMA expression at the tumour-advancing front were significantly associated with ECS (P<0.001). ECS was associated with expression of either or both proteins in all cases. SMA+/SERPINE1+ expression in combination was highly significantly associated with poor survival (P<0.001). MRI showed poor sensitivity for detection of nodal metastasis (56%) and ECS (7%). Both separately, and in combination, SERPINE1 and SMA were superior to MRI for the detection of ECS (sensitivity: SERPINE1: 95% SMA: 82% combination: 81%).Conclusion:A combination of SMA and SERPINE1 IHC offer potential as prognostic biomarkers in OSCC. Our findings suggest that biomarkers at the invasive front are likely to be necessary in prediction of ECS or in therapeutic stratification.

Background:Primary radiotherapy (RT) is a mainstay of treatment for laryngeal squamous cell carcinoma (LSCC). Although the cure rates for early (T1) vocal cord tumours are high, RT proves ineffective in up to a third of T3 carcinomas. Moreover, RT is associated with debilitating early- and late-treatment-related toxicity, thus finding means to de-escalate therapy, while retaining/augmenting therapeutic effectiveness, is highly desirable. p53 is a key mediator of radiation responses; we therefore investigated whether Nutlin-3, a small-molecule inhibitor of MDM2 (mouse double minute 2; an essential negative regulator of p53), might radiosensitise LSCC cells.Methods:We performed clonogenic assays to measure radiosensitivity in a panel of LSCC cell lines (for which we determined p53 mutational status) in the presence and absence of Nutlin-3.Results:LSCC cells harbouring wild-type p53 were significantly radiosensitised by Nutlin-3 (P<0.0001; log-rank scale), and displayed increased cell cycle arrest and significantly increased senescence (P<0.001) in the absence of increased apoptosis; thus, our data suggest that senescence may mediate this increased radiosensitivity.Conclusion:This is the first study showing Nutlin-3 as an effective radiosensitiser in LSCC cells that retain wild-type p53. The clinical application of Nutlin-3 might improve local recurrence rates or allow treatment de-escalation in these patients.

Abstract. The aim of this study was to investigate the outcome of patients with muscle-invasive bladder cancer (MIBC) receiving neo-adjuvant chemotherapy (neo-CT) using a cisplatin-based regimen fractionated on days 1 and 8 of a 21-day cycle prior to organ-preservation (chemoradiation) or cystectomy. Patients with stage T2-T4, N0, M0, transitional cell carcinoma (TCC) of the bladder with a calculated glomerular filtration rate (GFR) ≥40 ml/min were eligible for inclusion in the study. Neo-CT comprised of gemcitabine (1,000 mg/m 2 d1, d8, q21) plus cisplatin (35 mg/m 2 d1, d8, q21) for four cycles. Following the administration of neo-CT, patients underwent surgery or radiotherapy (RT) with or without concurrent chemotherapy (CRT), based on the response to neo-CT and clinician and patient preference. A total of 23 patients were recruited: 21 males and 2 females; median age, 69 years (range, 49-85); stage T2=11, T3A=7, T3B=5, grade 2=1, grade 3=22. One patient progressed prior to neo-CT. In total, 75 cycles of neo-CT were administered. Treatment was well-tolerated with only one episode of neutropenic sepsis. Three of 22 patients developed early progression and did not receive radical treatment. For the remaining 19 patients, choice of definitive treatment (surgery vs. RT/CRT) was based on response to neo-CT. Eight patients had residual disease at cystoscopy following the completion of neo-CT; six patients underwent surgery and two underwent RT/CRT. A total of 11 patients had a complete response (CR) to neo-CT, nine of whom were treated by RT/CRT, with the remaining two declining radical treatment. Median follow-up for alive patients was 57 months (range, 4.4-68.5). Three-year survival was 37% (95% CI 17-58%) and 5-year survival was 31% (95% CI 15-52%). Neo-CT is effective and well-tolerated in MIBC. This split-dose cisplatin regimen facilitates treatment in an outpatient setting and allows inclusion of patients with compromised GFR. IntroductionBladder cancer is the second most common genitourinary malignancy and is a significant cause of morbidity and mortality. Almost 25% of patients have muscle-invasive disease at presentation (1,2). In North America, the treatment of choice for muscle invasive bladder cancer is radical cystectomy and bilateral pelvic lymph node dissection. Although surgery may be curative, approximately 50% of all patients with muscle invasive transitional cell carcinoma (TCC) develop metastatic disease within 2 years of cystectomy and subsequently succumb to the disease, presumably due to a significant proportion of patients harboring micrometastatic disease (3). On this basis, neo-adjuvant and adjuvant chemotherapy have been tested in numerous phase II and a few phase III studies (4-7).There are two principal rationales for neo-adjuvant chemotherapy: i) to improve survival in patients with micrometastatic disease and ii) to preserve the bladder by shrinking the primary tumour to facilitate radiotherapy as an alternative definitive therapy to surgery (8). The results of the South Western Oncol...