TASK DEFINITION: Given a passage classify if the passage has a definite objective/aim/goal or not. Output '1' if the passage has a defininte objective/aim/goal and output '0' if the passage does not have a definite objective/aim/goal.
PROBLEM: FoxO transcription factors have been reported to play pivotal roles in tumorigenesis and drug resistance. The mechanisms underlying the tumor suppression function of FoxOs in human cancers remain largely unknown. Aberrant expression and activation of Nrf2 often correlate with chemoresistance and poor prognosis. Here, we report that FoxO3 directs the basal transcription of Kelch-like ECH-associated protein 1 (Keap1), an adaptor protein that bridges Nrf2 to Cul3 for degradation. FoxO3 depletion resulted in Keap1 down-regulation, thereby activating Nrf2 signaling. We further demonstrated that inhibition of the FoxO3-Keap1 axis accounts for Nrf2 induction and activation induced by constitutively active AKT signaling or tumor necrosis factor α treatment. Unlike previous findings, FoxO3 silencing led to decreased reactive oxygen species production, therefore protecting cells from oxidative stress-induced killing in an Nrf2-dependent manner. Importantly, FoxO3 deficiency strongly potentiated tumor formation in nude mice and rendered cholangiocarcinoma xenografts resistant to cisplatin-induced cell death by activating Nrf2. Additionally, we found that clinical cholangiocarcinoma samples displayed FoxO3-Keap1 down-regulation and Nrf2 hyperactivation, underscoring the essential roles of these proteins in cholangiocarcinoma development.

SOLUTION: 0

PROBLEM: The efficacy of immunotherapy against advanced cancer may be improved by combination strategies. Photodynamic therapy (PDT) is a local tumor ablation method based on localized activation of a photosensitizer, leading to oxygen radical-induced tumor cell death. PDT can enhance antitumor immune responses by release of antigen and danger signals, supporting combination protocols of PDT with immunotherapy.', 'We investigated the local and systemic immune effects of PDT after treatment of established tumors. In two independent aggressive mouse tumor models, TC-1 and RMA, we combined PDT with therapeutic vaccination using synthetic long peptides (SLP) containing epitopes from tumor antigens.', 'PDT of established tumors using the photosensitizer Bremachlorin resulted in significant delay of tumor outgrowth. Combination treatment of PDT with therapeutic SLP vaccination cured one third of mice. Importantly, all cured mice were fully protected against subsequent tumor rechallenge, and combination treatment of primary tumors led to eradication of distant secondary tumors, indicating the induction of a systemic antitumor immune response. Indeed, PDT by itself induced a significant CD8(+) T-cell response against the tumor, which was increased when combined with SLP vaccination and essential for the therapeutic effect of combination therapy.

SOLUTION: 1

PROBLEM: To examine the effect of Eubacterium limosum (E. limosum) on colonic epithelial cell line in vitro, and to evaluate the effect of E. limosum on experimental colitis.', 'E. limosum was inoculated anaerobically and its metabolites were obtained. The growth stimulatory effect of the E. limosum metabolites on T84 cells was evaluated by SUDH activity, and the anti-inflammatory effect by IL-6 production. The change in mRNA of toll like receptor 4 (TLR4) was evaluated by real time PCR. Colitis was induced by feeding BALB/C mice with 2.0% dextran sodium sulfate. These mice received either 5% lyophilized E. limosum (n = 7) or control diet (n = 7). Seven days after colitis induction, clinical and histological scores, colon length, and cecal organic acid levels were determined.', 'The E. limosum produced butyrate, acetate, propionate, and lactate at 0.25, 1.0, 0.025 and 0.07 mmol/L, respectively in medium. At this concentration, each acid had no growth stimulating activity on T84 cells; however, when these acids were mixed together at the above levels, it showed significantly high activity than control. Except for lactate, these acids significantly attenuated IL-6 production at just 0.1 mmol/L. In addition, under TNF-alpha stimulation, butyrate attenuated the production of TLR4 mRNA. The treatment with E. limosum significantly attenuated clinical and histological scores of colitis with an increase of cecal butyrate levels, compared with the control group.

SOLUTION:
1