TASK DEFINITION: Given a passage, 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: To examine the expression of Twist1 in cervical cancer and to explore its biological function in the progression of cervical cancer.\u2029', 'The expressions of Twist1 in 32 cervical cancers and matched normal tissues were examined by immunohistochemistry (IHC). Cell invasive ability and the expression of invasion-related genes were determined in RNAi-based Twist1-silencing HeLa cells. The relationship between Twist1 and microRNA-33a (miR-33a) in cervical cancer was studied by Pearson correlation analysis, and the roles of miR-33a in regulation of Twist1 and cell invasiveness were studied.\u2029', 'The positive expression rate of Twist1 was 75.0% (24/32) and 21.9% (7/32) in the cervical cancer and the matched normal tissues, respectively, with significant difference between them (P<0.05). Twist1 shRNA significantly decreased the invasiveness of HeLa cells (P<0.05). Compared with the matched normal tissues, the expression of miR-33a was increased in the cervical cancer tissues, which was negatively correlated with Twist1 (r=-0.661, P<0.05). Overexpression of miR-33a could significantly suppress Twist1 expression as well as cell invasiveness (P<0.05).\u2029

SOLUTION: Does [ MicroRNA-33a regulate the invasion of cervical cancer cells via targeting Twist1 ]?

PROBLEM: To determine whether the number and location of positive surgical margins (PSMs) in radical prostatectomy (RP) surgical specimens affect biochemical recurrence (BCR) rates.', 'The locations of PSMs were recorded for 1308 consecutive men who underwent RP between October 2000 and December 2006. BCR was defined as three consecutive prostate-specific antigen (PSA) level rises with the peak level >or=0.15 ng/mL. Multivariate regression analyses were used to identify preoperative predictors of PSMs and BCR. The estimated 5-year risk of BCR was calculated using the Kaplan-Meier method.', 'In all, 128 (9.8%) men had one or more PSMs. The mean body mass index, mean preoperative serum PSA level, the distributions of clinical stage and biopsy Gleason scores, and the presence or absence of biopsy perineural invasion were significantly different between men with or with no PSMs. In multivariate analysis, baseline serum PSA level, Gleason score and perineural invasion were independent preoperative predictors of PSMs. The 5-year actuarial BCR rates were dependent on the site of the PSM (P = 0.035) and not the number of PSMs (P = 0.18). The rank order of estimated 5-year BCR rates according to the site of PSMs were base > anterior > posterolateral > apex approximately posterior.

SOLUTION: Does site of positive surgical margins influence biochemical recurrence after radical prostatectomy?

PROBLEM: Consumption of vegetables and fruits, physical activity, obesity and caloric intake are all strongly related to the risk of colorectal cancer (CRC). The association between dietary intake of carotenoids from vegetables/fruits and risk of CRC in the context of cigarette smoking was studied in a nutritionally diverse population.', 'The study included 1,817 age sex residence-matched case-control pairs from a population-based study in Northern Israel. Data were acquired by food-frequency questionnaire. Individual intake of carotenoid isomers was calculated using an Israeli food content database. Odds ratios (ORs) were calculated using conditional logistic regression models adjusted for known risk factors.', 'Strong inverse associations were found with consumption of 9-cis-beta-carotene (OR = 0.35, 0.26-0.47), all-trans-beta-carotene (OR = 0.58, 0.44-0.76), cis-beta-cryptoxanthin (OR = 0.67, 0.50-0.90), all-trans-zeaxanthin (OR = 0.64, 0.48-0.86), and lutein (OR = 0.74, 0.57-0.96). Lycopene (OR = 2.22, 1.71-2.89) and all-trans-beta-cryptoxanthin (OR = 2.01, 1.48-2.73) were associated with increased risk of CRC. Inverse associations of most carotenoids with CRC, demonstrated in non-smokers, were much attenuated or reversed in past or current smokers with a highly significant interaction term.

SOLUTION:
Does smoking attenuate the negative association between carotenoids consumption and colorectal cancer risk?