Reviewer's report
Title:Expression, localization and polymorphisms of the nuclear receptor PXR in
Barrett's esophagus and esophageal adenocarcinoma
Version: 8Date:16 August 2010
Reviewer: Katerina Dvorak
Reviewer's report:
Expression, localization and polymorphism of the nuclear receptor PXR in
Barrett’s esophagus and esophageal adenocarcinoma
Anouk Van de Winkel, et al.
In this paper, the authors evaluated PXR expression, localization and
polymorphism in normal squamous esophageal mucosa, Barrett’s esophagus
and esophageal adenocarcinoma. This is a well-written paper introducing novel
bile-acid activated pathway that involves PXR receptor. Although this paper is
very interesting, there are some issues that need to be explained more
thoroughly. The quality of the images is very good, however two figures were not
correctly converted to pdf file and it is not possible to evaluate the data.
Major Revision:
1. Figure 1 is not labeled. I think that there were problems with conversion to pdf
file.
2. The authors need to justify why lithocholic acid and taurolithocholic acid were
used in in vitro experiments. This bile acid is not common in the refluxate of BE
patients and the concentrations used are not physiological. In addition, this bile
acid is not very soluble. What is the effect of more common bile acids? Is the
effect of LCA similar in OE33 cells and HET1A cells (translocation to nucleus)?
3. Lithocholic acid is one of the most cytotoxic bile acids. At the concentration of
100uM for 24 hours, what was the effect of LCA and TLCA on cell survival in
both cell lines? Furthermore, the authors should justify why 24 hours treatment
was used, since reflux episodes are usually in terms of minutes.
4. The magnifications in Figure 3B are not same, it needs to be corrected. The
images suggest that after stimulation with LCA overall PXR expression increases
and possibly PXR is translocated to nucleus. Western blot data would answer
this question more definitely. The figure legend also should indicate
magnification.
5. Table 3 shows allele frequencies at SNPs locus at 7635 and 8055. While
healthy controls are compared with reflux esophagitis or BE, there is no
comparison between BE and reflux esophagitis. Are the allele frequencies also
significantly different between BE and RE? If not than the conclusion is not
correct. Also, it would be interesting in future studies to evaluate if there is any
difference in SNPs between different grades of BE dysplasia.
6. Figure 4 was not converted to pdf file.
Minor Revision:
1. Spelling page 6 “a specific“
2. Spelling: page 5 “taurolithocholic acid”
Discretionary Revisions:
1. The authors should speculate why immunohistochemical studies show low
protein expression in BE but high in adenocarcinoma, but PXR mRNA levels are
not different in BE and adenocarcinoma tissue.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Reviewer's report
Title:Expression, localization and polymorphisms of the nuclear receptor PXR in
Barrett's esophagus and esophageal adenocarcinoma
Version: 8Date:16 August 2010
Reviewer: Katerina Dvorak
Reviewer's report:
Expression, localization and polymorphism of the nuclear receptor PXR in
Barrett’s esophagus and esophageal adenocarcinoma
Anouk Van de Winkel, et al.
In this paper, the authors evaluated PXR expression, localization and
polymorphism in normal squamous esophageal mucosa, Barrett’s esophagus
and esophageal adenocarcinoma. This is a well-written paper introducing novel
bile-acid activated pathway that involves PXR receptor. Although this paper is
very interesting, there are some issues that need to be explained more
thoroughly. The quality of the images is very good, however two figures were not
correctly converted to pdf file and it is not possible to evaluate the data.
Major Revision:
1. Figure 1 is not labeled. I think that there were problems with conversion to pdf
file.
2. The authors need to justify why lithocholic acid and taurolithocholic acid were
used in in vitro experiments. This bile acid is not common in the refluxate of BE
patients and the concentrations used are not physiological. In addition, this bile
acid is not very soluble. What is the effect of more common bile acids? Is the
effect of LCA similar in OE33 cells and HET1A cells (translocation to nucleus)?
3. Lithocholic acid is one of the most cytotoxic bile acids. At the concentration of
100uM for 24 hours, what was the effect of LCA and TLCA on cell survival in
both cell lines? Furthermore, the authors should justify why 24 hours treatment
was used, since reflux episodes are usually in terms of minutes.
4. The magnifications in Figure 3B are not same, it needs to be corrected. The
images suggest that after stimulation with LCA overall PXR expression increases
and possibly PXR is translocated to nucleus. Western blot data would answer
this question more definitely. The figure legend also should indicate
magnification.
5. Table 3 shows allele frequencies at SNPs locus at 7635 and 8055. While
healthy controls are compared with reflux esophagitis or BE, there is no
comparison between BE and reflux esophagitis. Are the allele frequencies also
significantly different between BE and RE? If not than the conclusion is not
correct. Also, it would be interesting in future studies to evaluate if there is any
difference in SNPs between different grades of BE dysplasia.
6. Figure 4 was not converted to pdf file.
Minor Revision:
1. Spelling page 6 “a specific“
2. Spelling: page 5 “taurolithocholic acid”
Discretionary Revisions:
1. The authors should speculate why immunohistochemical studies show low
protein expression in BE but high in adenocarcinoma, but PXR mRNA levels are
not different in BE and adenocarcinoma tissue.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Please review this paper.
user
Reviewer's report
Title:Expression, localization and polymorphisms of the nuclear receptor PXR in
Barrett's esophagus and esophageal adenocarcinoma
Version: 8Date:16 August 2010
Reviewer: Katerina Dvorak
Reviewer's report:
Expression, localization and polymorphism of the nuclear receptor PXR in
Barrett’s esophagus and esophageal adenocarcinoma
Anouk Van de Winkel, et al.
In this paper, the authors evaluated PXR expression, localization and
polymorphism in normal squamous esophageal mucosa, Barrett’s esophagus
and esophageal adenocarcinoma. This is a well-written paper introducing novel
bile-acid activated pathway that involves PXR receptor. Although this paper is
very interesting, there are some issues that need to be explained more
thoroughly. The quality of the images is very good, however two figures were not
correctly converted to pdf file and it is not possible to evaluate the data.
Major Revision:
1. Figure 1 is not labeled. I think that there were problems with conversion to pdf
file.
2. The authors need to justify why lithocholic acid and taurolithocholic acid were
used in in vitro experiments. This bile acid is not common in the refluxate of BE
patients and the concentrations used are not physiological. In addition, this bile
acid is not very soluble. What is the effect of more common bile acids? Is the
effect of LCA similar in OE33 cells and HET1A cells (translocation to nucleus)?
3. Lithocholic acid is one of the most cytotoxic bile acids. At the concentration of
100uM for 24 hours, what was the effect of LCA and TLCA on cell survival in
both cell lines? Furthermore, the authors should justify why 24 hours treatment
was used, since reflux episodes are usually in terms of minutes.
4. The magnifications in Figure 3B are not same, it needs to be corrected. The
images suggest that after stimulation with LCA overall PXR expression increases
and possibly PXR is translocated to nucleus. Western blot data would answer
this question more definitely. The figure legend also should indicate
magnification.
5. Table 3 shows allele frequencies at SNPs locus at 7635 and 8055. While
healthy controls are compared with reflux esophagitis or BE, there is no
comparison between BE and reflux esophagitis. Are the allele frequencies also
significantly different between BE and RE? If not than the conclusion is not
correct. Also, it would be interesting in future studies to evaluate if there is any
difference in SNPs between different grades of BE dysplasia.
6. Figure 4 was not converted to pdf file.
Minor Revision:
1. Spelling page 6 “a specific“
2. Spelling: page 5 “taurolithocholic acid”
Discretionary Revisions:
1. The authors should speculate why immunohistochemical studies show low
protein expression in BE but high in adenocarcinoma, but PXR mRNA levels are
not different in BE and adenocarcinoma tissue.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
assistant