instruction:
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.
question:
To examine the expression of Twist1 in cervical cancer and to explore its biological function in the progression of cervical cancer.
', '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.
', '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).

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

question:
The inducible nitric oxide synthase (iNOS) is associated with inflammatory processes and cancer formation through production of nitric oxide (NO). However, the clinical importance of the expression of iNOS in oral cancer remains unclear. In the present study, we examined whether up-regulation of the iNOS gene can affect growth and metastasis of an oral cancer cell line (B88t cell) in vitro and in vivo.', 'We constructed an expression vector containing sense-oriented murine iNOS cDNA with pcDNA3.1. We transfected B88t cells with the sense expression vector to up-regulate the expression of the iNOS gene in the sense transfectants.', 'The expression of iNOS protein was up-regulated in the sense transfectants and that up-regulation of the iNOS gene exerted a growth inhibitory effect on B88t cells in vitro and in vivo. Moreover, up-regulation of the iNOS gene markedly inhibited the migration of cancer cells in a Boyden chamber. Furthermore, up-regulation of the iNOS gene dramatically inhibited metastases to the cervical lymph node in vivo.
answer:
Does overexpression of iNOS gene suppress the tumorigenicity and metastasis of oral cancer cells?

question:
The present study was conducted to determine whether preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and whether the increase of plasma atrial natriuretic peptides improves the ability of the kidneys to excrete the fluid load after the operation.', 'We evaluated 42 patients who underwent the maze procedure. The right atrial appendage was preserved in 22 patients but not in 20. Blood samples were obtained before and after the operation for measurement of atrial natriuretic peptides. To evaluate the influence of atrial natriuretic peptides on the ability of the kidneys, we also measured body weight, fluid balance, and the doses of furosemide and dopamine administered after the operation.', 'The restoration to sinus rhythm at 1 month after was comparable in the two groups. Plasma atrial natriuretic peptide levels significantly increased after the operation in patients in whom the right atrial appendage was preserved (1 day after: 23.4 +/- 17.8 vs 3 days after: 42.7 +/- 23.6 and 7 days after: 36.3 +/- 23.7 pg/mL, P <.05) but not in patients in whom the right atrial appendage was not preserved (1 day after: 20.0 +/- 19.6, 3 days after: 28.5 +/- 19.3, and 7 days after: 23.0 +/- 16.1 pg/mL). Furthermore, plasma atrial natriuretic peptide levels were significantly lower in patients in whom the right atrial appendage was not preserved than in patients in whom the right atrial appendage was preserved at 3 and 7 days after the operation. The fluid balance during the first 7 days of the postoperative period was comparable in the two groups, although the total dose of dopamine used in the same period was significantly smaller in patients in whom the right atrial appendage was preserved than in patients in whom the right atrial appendage was not preserved (155.3 +/- 119.0 vs 244.9 +/- 129.0 microg/kg, P <.05).
answer:
Does preservation of the right atrial appendage improve reduced plasma atrial natriuretic peptide levels after the maze procedure?