Reviewer's report
Title:Epigenetic mechanisms involved in differential MDR1 mRNA expression
between gastric and colon cancer cell lines and rationales for clinical
chemotherapy
Version: 2Date:28 March 2008
Reviewer: Masakazu Yashiro
Reviewer's report:
Major Compulsory Revisions
The authors have not answered our points sufficiently. This paper is
not recommended for publication in this form.
Major Comments:
Authors’ reply is insufficient for request. Authors show few
additional data. While the revised manuscript is improved, its
conclusions are speculative and not supported by the experiments shown.
Minor Comments:
1. Determined quantity of PgP protein in cancer cells and its
correlation with expression mRNA of MDR1 might be required, because
results of isotopic PCR are different from real-time RT-PCR.
2. Examination of methylation status by bisulfite treatment is
necessary. Direct sequencing of promoter region with or without
bisulfite treatment might be useful to examine the methylation status
at in gastric and colon cancer cell lines.
3. In inhibition assay using 5-AC and TSA, functional effect of
them should be clarified for example, in chemo-sensitivity assay or
Pgp protein expression assay.
4. If authors insist on rationale of clinical chemotherapy
described in title and as they also described in discussion, they
should examine effect of other drugs commonly used for gastric and
colon cancer such as 5-FU, irinotecan, and oxaliplatin.
Reviewer's report
Title:Epigenetic mechanisms involved in differential MDR1 mRNA expression
between gastric and colon cancer cell lines and rationales for clinical
chemotherapy
Version: 2Date:28 March 2008
Reviewer: Masakazu Yashiro
Reviewer's report:
Major Compulsory Revisions
The authors have not answered our points sufficiently. This paper is
not recommended for publication in this form.
Major Comments:
Authors’ reply is insufficient for request. Authors show few
additional data. While the revised manuscript is improved, its
conclusions are speculative and not supported by the experiments shown.
Minor Comments:
1. Determined quantity of PgP protein in cancer cells and its
correlation with expression mRNA of MDR1 might be required, because
results of isotopic PCR are different from real-time RT-PCR.
2. Examination of methylation status by bisulfite treatment is
necessary. Direct sequencing of promoter region with or without
bisulfite treatment might be useful to examine the methylation status
at in gastric and colon cancer cell lines.
3. In inhibition assay using 5-AC and TSA, functional effect of
them should be clarified for example, in chemo-sensitivity assay or
Pgp protein expression assay.
4. If authors insist on rationale of clinical chemotherapy
described in title and as they also described in discussion, they
should examine effect of other drugs commonly used for gastric and
colon cancer such as 5-FU, irinotecan, and oxaliplatin.
Please review this paper.
user
Reviewer's report
Title:Epigenetic mechanisms involved in differential MDR1 mRNA expression
between gastric and colon cancer cell lines and rationales for clinical
chemotherapy
Version: 2Date:28 March 2008
Reviewer: Masakazu Yashiro
Reviewer's report:
Major Compulsory Revisions
The authors have not answered our points sufficiently. This paper is
not recommended for publication in this form.
Major Comments:
Authors’ reply is insufficient for request. Authors show few
additional data. While the revised manuscript is improved, its
conclusions are speculative and not supported by the experiments shown.
Minor Comments:
1. Determined quantity of PgP protein in cancer cells and its
correlation with expression mRNA of MDR1 might be required, because
results of isotopic PCR are different from real-time RT-PCR.
2. Examination of methylation status by bisulfite treatment is
necessary. Direct sequencing of promoter region with or without
bisulfite treatment might be useful to examine the methylation status
at in gastric and colon cancer cell lines.
3. In inhibition assay using 5-AC and TSA, functional effect of
them should be clarified for example, in chemo-sensitivity assay or
Pgp protein expression assay.
4. If authors insist on rationale of clinical chemotherapy
described in title and as they also described in discussion, they
should examine effect of other drugs commonly used for gastric and
colon cancer such as 5-FU, irinotecan, and oxaliplatin.
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