In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
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Question: Context: Celastrol is an active ingredient of traditional herbal medicine and has recently been identified as a potent natural proteasome inhibitor. In the present study, we evaluated the radiosensitizing potential of celastrol in the human prostate cancer PC-3 model.', 'Clonogenic assays were performed to determine the radiosensitizing effect of celastrol. Apoptosis was examined by flow cytometry using Annexin V and propidium iodide staining and by a caspase-3 activation assay. DNA damage processing was examined by immunofluorescent staining and Western blot for phosphorylated H2AX (gammaH2AX). The PC-3 xenograft model in the athymic nude mouse was used for the determination of the in vivo efficacy of celastrol combined with radiotherapy. The tumor samples were also analyzed for apoptosis and angiogenesis.', 'Celastrol sensitized PC-3 cells to ionizing radiation (IR) in a dose- and schedule-dependent manner, in which pretreatment with celastrol for 1 h followed by IR achieved maximal radiosensitization. Celastrol significantly prolonged the presence of IR-induced gammaH2AX and increased IR-induced apoptosis. Celastrol, combined with fractionated radiation, significantly inhibited PC-3 tumor growth in vivo without obvious systemic toxicity. The combination treatment increased gammaH2AX levels and apoptosis, induced cleavage of poly(adenosine diphosphate-ribose)polymerase and Mcl-1, and reduced angiogenesis in vivo compared with either treatment alone.\Question: Does celastrol potentiate radiotherapy by impairment of DNA damage processing in human prostate cancer?

Answer: Celastrol sensitized PC-3 cells to radiation both in vitro and in vivo by impairing DNA damage processing and augmenting apoptosis. Celastrol might represent a promising new adjuvant regimen for the treatment of hormone-refractory prostate cancer.

Question: Context: Recent studies have identified MUC4 mucin as a ligand for activation of ErbB2, a receptor tyrosine kinase that modulates epithelial cell proliferation following epithelial damage in airways of asthmatics. In this study, we investigated the potential role of IL-4, one of the Th2 inflammatory cytokines persistent in asthmatic airways, in regulating MUC4 expression using a cell line NCI-H650.', 'Real time PCR analysis was performed to determine concentration and time dependent effects of IL-4 upon MUC4 expression. Nuclear run on experiments were carried out to explore potential transcriptional modulation. Western blotting experiments using a monoclonal antibody specific to ASGP-2 domain of MUC4 were performed to analyze MUC4 glycoprotein levels in plasma membrane fractions. To analyze potential signal transduction cascades, IL-4 treated confluent cultures were co-incubated, separately with a pan-JAK inhibitor, a JAK-3 selective inhibitor or a MEK-1, 2 (MAPK) inhibitor at various concentrations before MUC4 transcript analysis. Corresponding transcription factor activation was tested by western blotting using a monoclonal p-STAT-6 antibody.', 'MUC4 levels increased in a concentration and time specific fashion reaching peak expression at 2.5 ng/ml and 8 h. Nuclear run on experiments revealed transcriptional enhancement. Corresponding increases in MUC4 glycoprotein levels were observed in plasma membrane fractions. Pan-JAK inhibitor revealed marked reduction in IL-4 stimulated MUC4 levels and JAK3 selective inhibitor down-regulated MUC4 mRNA expression in a concentration-dependent fashion. In accordance with the above observations, STAT-6 activation was detected within 5 minutes of IL-4 stimulus. No effect in MUC4 levels was observed on using a MAPK inhibitor.\Question: Is iL-4 induced MUC4 enhancement in respiratory epithelial cells in vitro mediated through JAK-3 selective signaling?

Answer: These observations signify a potential role for IL-4 in MUC4 up-regulation in airway epithelia.

Question: Context: Serum levels of matrix metalloproteinase-9 (MMP-9) which agree with progression in solid and haematological tumours were correlated to the risk of disease progression in 62 patients with early (Binet stage A) B-cell chronic lymphocytic leukaemia (CLL). Sera were taken at diagnosis and tested by an enzyme-linked immunosorbent assay.', 'MMP-9 levels positively correlated with haemoglobin levels (P = 0.03) and platelet count (P = 0.03). No association was found with main clinico-haematological features representative of tumour mass, such as peripheral blood lymphocytosis, bone marrow histology, Rai substages and beta-2 microglobulin (beta-2m). A cut-off of MMP-9 levels corresponding to 33rd percentile (203 ng/mL) or higher identified earlier upstaging and shorter progression-free survival. MMP-9 was a significant prognostic marker in multivariate analysis and partially independent of Rai substages, which suggests its inclusion into such a staging system to better stratify prognostically Rai stages I and II patients.\Question: Do increased serum levels of matrix metalloproteinase-9 predict clinical outcome of patients with early B-cell chronic lymphocytic leukaemia?

Answer:
MMP-9 serum levels predict disease behaviour and help to refine the prognosis of stage A CLL patients.