TASK DEFINITION: Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
PROBLEM: Context: Early metastasis in node-negative breast cancer indicates that breast cancer cells obviously can bypass the lymph nodes and disseminate directly hematogenous to distant organs. For this purpose, we evaluated the prognostic value of blood-borne, HER2-positive circulating tumor cells (CTC) in the peripheral blood from 42 breast cancer patients with a median follow-up of 95 months.', 'Cells were isolated by the patented combined buoyant density gradient and immunomagnetic separation procedure and analyzed by immunocytochemistry.', 'We detected one to eight CTCs in the peripheral blood of 17 of 35 patients (48.6%) presenting no overt metastasis. As a positive control, 7 of 7 (100%) patients with metastatic disease presented positive. Healthy persons and patients (n = 32) operated for nonmalignant diseases presented negative for CTCs. The presence and frequency of HER2-positive CTCs correlated with a significantly decreased disease-free survival (P < 0.005) and overall survival (P < 0.05). Interestingly, in 12 patients with HER2-positive CTCs, the primary tumor was negative for HER2 as assessed by immunohistochemical score and fluorescence in situ hybridization.
Answer: This study provides some evidence of a prognostic effect of HER2-positive CTCs in stage I to III breast cancer. Future studies have to determine the outcome of patients treated with HER2-targeting therapies with respect to HER2-positive CTC levels because it is not unlikely that high levels of HER2-positive CTCs reflect the activity of the tumor and may predict response to trastuzumab.

SOLUTION: Do hER2-positive circulating tumor cells indicate poor clinical outcome in stage I to III breast cancer patients?

PROBLEM: Context: Stomatal guard cells monitor and respond to environmental and endogenous signals such that the stomatal aperture is continually optimised for water use efficiency. A key signalling molecule produced in guard cells in response to plant hormones, light, carbon dioxide and pathogen-derived signals is hydrogen peroxide (H(2)O(2)). The mechanisms by which H(2)O(2) integrates multiple signals via specific signalling pathways leading to stomatal closure is not known.', 'Here, we identify a pathway by which H(2)O(2), derived from endogenous and environmental stimuli, is sensed and transduced to effect stomatal closure. Histidine kinases (HK) are part of two-component signal transduction systems that act to integrate environmental stimuli into a cellular response via a phosphotransfer relay mechanism. There is little known about the function of the HK AHK5 in Arabidopsis thaliana. Here we report that in addition to the predicted cytoplasmic localisation of this protein, AHK5 also appears to co-localise to the plasma membrane. Although AHK5 is expressed at low levels in guard cells, we identify a unique role for AHK5 in stomatal signalling. Arabidopsis mutants lacking AHK5 show reduced stomatal closure in response to H(2)O(2), which is reversed by complementation with the wild type gene. Over-expression of AHK5 results in constitutively less stomatal closure. Abiotic stimuli that generate endogenous H(2)O(2), such as darkness, nitric oxide and the phytohormone ethylene, also show reduced stomatal closure in the ahk5 mutants. However, ABA caused closure, dark adaptation induced H(2)O(2) production and H(2)O(2) induced NO synthesis in mutants. Treatment with the bacterial pathogen associated molecular pattern (PAMP) flagellin, but not elf peptide, also exhibited reduced stomatal closure and H(2)O(2) generation in ahk5 mutants.
Answer: Our findings identify an integral signalling function for AHK5 that acts to integrate multiple signals via H(2)O(2) homeostasis and is independent of ABA signalling in guard cells.

SOLUTION: Does the histidine kinase AHK5 integrate endogenous and environmental signals in Arabidopsis guard cells?

PROBLEM: Context: Recent studies have indicated a protective role of physiological autophagy in ischemic heart disease. However, the underlying mechanisms of autophagy regulation after ischemia are poorly understood. Exosomes are nano-sized vesicles released from cells that play critical roles in mediating cell-to-cell communication through the transfer of microRNAs. In this study, we observed that miR-30a was highly enriched in exosomes from the serum of acute myocardial infarction (AMI) patients in vivo and culture medium of cardiomyocytes after hypoxic stimulation in vitro. We also found that hypoxia inducible factor (HIF)-1 regulates miR-30a, which efficiently transferred via exosomes between cardiomyocytes after hypoxia. Inhibition of miR-30a or release of exosomes increased the expression of the core autophagy regulators beclin-1, Atg12, and LC3II/LC3I, which contributed to maintaining the autophagic response in cardiomyocytes after hypoxia. Taken together, the present study showed that exosomes from hypoxic cardiomyocytes regulate autophagy by transferring miR-30a in a paracrine manner, which revealed a new pathway of autophagy regulation that might comprise a promising strategy to treat ischemic heart disease.
Answer: miR-30a is highly enriched in exosomes from the serum of AMI patients. Hypoxia induces miR-30a upregulation and enrichment into exosomes. MiR-30a is efficiently transferred via exosomes between hypoxic cardiomyocytes. Inhibition of exosome release contributes to maintaining of autophagy after hypoxia. Inhibition of miR-30a augments autophagy after hypoxia.

SOLUTION:
Does exosomal transfer of miR-30a between cardiomyocytes regulate autophagy after hypoxia?