Reviewer's report
Title:Deregulated Expression of Circadian Clock Genes in Gastric Cancers
Version: 1Date:9 October 2013
Reviewer: Richard G Stevens
Reviewer's report:
This is a small study of circadian gene expression in gastric cancer. The topic is
interesting and the study appears to have been carefully conducted. Given the
small sample size it is important that the authors acknowledge this limitation and
point out that the study had low power; real differences could easily have been
missed. For example, on page 6 it is stated
“Our data demonstrated only PER2 expression was significantly upregulated (p <
0.005) and the expression of the other seven genes was not different between
cancer and noncancerous tissues (Table 2 and Figure 1).”
The authors have confused ‘not statistically significant’ with ‘not different’. In fact
from figure 1 there are differences in expression of several of the genes (not just
Per2); these differences are not statistically significant, but in a larger study might
be found to be real. Also, as the authors point out, the Per2 difference is in the
opposite direction than expected based on previous studies. The final paragraph
of the Discussion is highly speculative, but that is fine because the speculations
are reasonable.
Also, in the Introduction, the word ‘proof’ should be avoided.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
no competing interests
Reviewer's report
Title:Deregulated Expression of Circadian Clock Genes in Gastric Cancers
Version: 1Date:9 October 2013
Reviewer: Richard G Stevens
Reviewer's report:
This is a small study of circadian gene expression in gastric cancer. The topic is
interesting and the study appears to have been carefully conducted. Given the
small sample size it is important that the authors acknowledge this limitation and
point out that the study had low power; real differences could easily have been
missed. For example, on page 6 it is stated
“Our data demonstrated only PER2 expression was significantly upregulated (p <
0.005) and the expression of the other seven genes was not different between
cancer and noncancerous tissues (Table 2 and Figure 1).”
The authors have confused ‘not statistically significant’ with ‘not different’. In fact
from figure 1 there are differences in expression of several of the genes (not just
Per2); these differences are not statistically significant, but in a larger study might
be found to be real. Also, as the authors point out, the Per2 difference is in the
opposite direction than expected based on previous studies. The final paragraph
of the Discussion is highly speculative, but that is fine because the speculations
are reasonable.
Also, in the Introduction, the word ‘proof’ should be avoided.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
no competing interests
Please review this paper.
user
Reviewer's report
Title:Deregulated Expression of Circadian Clock Genes in Gastric Cancers
Version: 1Date:9 October 2013
Reviewer: Richard G Stevens
Reviewer's report:
This is a small study of circadian gene expression in gastric cancer. The topic is
interesting and the study appears to have been carefully conducted. Given the
small sample size it is important that the authors acknowledge this limitation and
point out that the study had low power; real differences could easily have been
missed. For example, on page 6 it is stated
“Our data demonstrated only PER2 expression was significantly upregulated (p <
0.005) and the expression of the other seven genes was not different between
cancer and noncancerous tissues (Table 2 and Figure 1).”
The authors have confused ‘not statistically significant’ with ‘not different’. In fact
from figure 1 there are differences in expression of several of the genes (not just
Per2); these differences are not statistically significant, but in a larger study might
be found to be real. Also, as the authors point out, the Per2 difference is in the
opposite direction than expected based on previous studies. The final paragraph
of the Discussion is highly speculative, but that is fine because the speculations
are reasonable.
Also, in the Introduction, the word ‘proof’ should be avoided.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
no competing interests
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