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.

Ex Input:
Context: Resistance to cisplatin-centered chemotherapy is a major cause of treatment failure in human ovarian cancer. Whereas PTEN, a tumor suppressor gene product, is believed to promote apoptosis primarily via inactivation of the PI3K/Akt cell survival pathway, recent evidence suggests that PTEN may function independently of this pathway. Activation of p53 is a key determinant of sensitivity to cisplatin-induced apoptosis. Whether PTEN can facilitate cisplatin sensitivity, and this involves the activation of p53, remains unclear. In this study, we determined whether and how PTEN over-expression sensitizes ovarian cancer cells to CDDP-induced apoptosis.', 'Using pairs of chemosensitive and chemoresistant ovarian cancer cell lines (OV20028 vs. C13* and A2780-s vs. A2780-cp) as an in vitro model, we have examined the influence of PTEN over-expression in regulation of cisplatin-induced apoptosis. Apoptosis was assessed morphologically by Hoechst staining and confirmed by the detection of cleaved products of caspase-3 and PARP by Western blot. Over-expression of PTEN by PTEN cDNA transfection up-regulates p53 content and increases the sensitivity of chemoresistant cells to cisplatin-induced apoptosis without detectable changes in the levels of phosphorylated Akt and FKHR as well as FasL mRNA abundance as determined by Western blot and RT-PCR, respectively. PTEN-mediated chemosensitization was attenuated by p53 down-regulation by siRNA in C13*, a chemoresistant wild-type p53 cell. Moreover, PTEN over-expression failed to sensitize the chemoresistant p53 mutant ovarian cancer cell line A2780-cp to cisplatin-induced apoptosis, unless wild-type p53 was reconstituted by adenoviral p53 infection.
Answer: Taken together, these data suggest that PTEN over-expression may represent a novel therapeutic approach for chemoresistant human ovarian cancer and that this may involve a p53-mediated apoptotic cascade independent of the PI3K/Akt pathway.

Ex Output:
Does over-expression of PTEN sensitize human ovarian cancer cells to cisplatin-induced apoptosis in a p53-dependent manner?


Ex Input:
Context: The single nucleotide polymorphism rs10494366 in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene is associated with QTc prolongation, through an effect on the intracellular Ca levels. As sulfonylurea stimulate insulin secretion by an increased influx of Ca, we hypothesized that this polymorphism is associated with the glucose-lowering effect and mortality risk in sulfonylurea users.', 'Associations between the NOS1AP polymorphism, prescribed doses, and mortality rates in sulfonylurea, metformin, and insulin users were assessed in the Rotterdam Study, a population-based cohort study of 7983 elderly people.', 'We identified 619 participants who were prescribed oral antidiabetic drugs during follow-up. In glibenclamide users carrying the TG genotype, the prescribed doses were higher compared with the glibenclamide users carrying the TT genotype [0.38 defined daily dose units, 95% confidence interval (CI) 0.14-0.63]. Glibenclamide users with the TG or GG genotype had an increased mortality risk compared with glibenclamide users with the TT genotype [hazard ratio (HR) 2.80, 95% CI: 1.09-7.22]. Tolbutamide users with the TG or GG genotype (HR: 0.30, 95% CI: 0.14-0.63) and glimepiride users with the TG or GG genotype (HR: 0.18, 95% CI: 0.04-0.74) had a decreased mortality risk compared with tolbutamide and glimepiride users with the TT genotype.
Answer: In participants with the TG or GG genotype at rs10494366 in the NOS1AP gene, glibenclamide is less effective in reducing glucose levels and mortality rates were higher compared with glibenclamide users with the TT genotype. In tolbutamide and glimepiride users, the TG and GG genotype were associated with a reduced mortality rate.

Ex Output:
Is common variation in the NOS1AP gene associated with reduced glucose-lowering effect and with increased mortality in users of sulfonylurea?


Ex Input:
Context: It has been suggested that prostate specific antigen has no predictive value for prostate cancer after a first negative biopsy has been performed. We compared the performance operating characteristics of prostate specific antigen for prostate cancer between a first and subsequent prostate biopsy in a group of men with complete verification of cancer status.', 'From the 18,882 participants in the Prostate Cancer Prevention Trial we examined men in the placebo group who had only a first biopsy or a first and second prostate biopsy with a prostate specific antigen and digital rectal examination within 1 year before each biopsy. The receiver operating characteristic curve was estimated for prostate specific antigen for detection of prostate cancer on the first biopsy compared to the second, and the C-statistics were compared.', 'Of this group 5,608 men had a first biopsy and 687 of those with a negative first biopsy underwent a second biopsy. The C-statistic was 0.650 (95% CI 0.632, 0.668) for the first biopsy and 0.664 (95% CI 0.607, 0.721) for the second biopsy. The C-statistic for the second biopsy was statistically significantly greater than 0.5 (p <0.001) and overlapped with that from the first biopsy.
Answer: Prostate specific antigen does not lose predictive value for the detection of prostate cancer even after a first biopsy shows no evidence of cancer, and its performance characteristics are only slightly decreased.

Ex Output:

Is the performance of prostate specific antigen for predicting prostate cancer maintained after a prior negative prostate biopsy?