Review for 10.1186/s12876-020-01272-5 (2020)

Reviewer ’s rep ort 
 
Title: LncRNA SNHG1 promotes EMT process in gastric cancer cells through regulation of the  
miR-15b/DCLK1/Notch1 axis  
 
Version: 1 Date: 05 Dec 2019  
 
Reviewer: Joo Hyun Lim  
 
Reviewer's report:  
 
This i s an experimental study which revealed that lncRNA SNHG1 promotes EMT in gastric 
cancer via DCLK1/Notch1 pathway which is regulated by miR -15b. Although the lncRNA 
SNHG1, DCLK1/Notch1 pathway, and miR -15b are already known to be related with gastric 
cancer , their relationship and mechanism have not been verified yet. This study has the strength 
of discovering their role in gastric cancer progression. However, there are several points to be 
discussed.  
 
Major  
1. The authors used 1 normal gastric mucosal cell  line and 3 gastric cancer cell line. 
However, it seems most of the experiments were performed only in N87 cell line. Then the 
phenomenon shown in this article might be only true in this cell line by chance. Therefore, to 
confirm the authors' hypothesis, I  recommend to perform all the experiments in the 3 cell lines. 
Also, please describe which one is normal gastric cell line, and which one is gastric cancer cell 
line, in the manuscript.  
2. The second sentence in the &lt;Background &gt;, "The ratio of early  diagnosis in 
gastric cancer is low, and metastasis ration of GC is high." Is too assertive. It varies a lot 
depending upon the geographic region and these days the early diagnosis rate is rapidly 
increasing in many countries. Therefore please show a numer ic data to support this sentence.  
3. Discussion is too short. The last sentence of the first paragraph says that DCLK1 
functions via Notch1 pathway, however, there are no such explanation about Notch1 pathway in 
this paragraph. This should be discussed be fore this sentence. Also, current knowledge about the 
role of lncRNA SNHG, and miR -15b should be explained in detail.  
4. Please add a paragraph about the limitation of this study.  
Minor  
1. There are lots of English grammar/syntax errors and typos in the manuscript and 
figures. Please have it checked by a native English speaker. Also read it thoroughly and correct 
the mistakes, such as DCKL1, DCKK1 or knockdown.  
2. Some figures are not cited in the manuscript. Please cite every figure in the manuscript 
in order. Also, there is no legend for figure 2(D).  
3. In line 41 of page 10, the sentence with "… expression level of miR -15b in GC cell 
lines was significantly increased …" seems to be corrected as "…. decreased… "  
 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the autho rs. 
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recomme nded, please specify what aspects require further  
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Not suitable for publication unless ext ensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may i n any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now  or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing inter ests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests.  
 
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on my report to the authors and, if the man uscript is accepted for publication, my named report  
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