Review for 10.1186/s12876-023-02815-2 (2023)

Reviewer’s report
Title:  Glucose metabolic upregulation via phosphorylation of S6 ribosomal protein affects tumor
progression in distal cholangiocarcinoma
Version: 1 Date: 16 Mar 2023
Reviewer's report:
In this work Fujinaga and collaborators evaluate the activity of the mTORC1 pathway by analyzing the
levels of S6 ribosomal protein phosphorylation (pS6) along with the expression of GLUT1 in dCCA
tissue samples. The authors observed a correlation between higher pS6 and GLUT1 tissue levels with
increased  FDG  tumor  uptake  (FDG-PET)  and  advanced  disease.  In  cultured  CCA  cells,  the
pharmacological inhibition of mTORC1 pathway resulted in reduced cell growth and lowered GLUT1
expression, along with reduced glycolysis and TCA pathways activity. This is a potentially interesting
study. Nevertheless, there are some issues for the authors to consider which if properly addressed may
increase the significance of this study.
1. The experiments in which the effects of PF are tested in CCA cells should be more complete. The 
GI50 doses of PF need to be calculated for all CCA cell lines. Moreover, these tretaments should be 
better described in the Methods section.
2. Regarding the data shown in Fig. 3d, the authors need to perform dose- and time-dependent studies 
on the effects of PF, and include all four cell lines.
3. Does PF affect the migratory and invasive capacity of CCA cells? Does PF induce apoptosis and/or 
cell cycle arrest in CCA cells?
4. It would be interesting to know if PF synergizes with chemotheraputics used for the management of 
CCA patients, such as platin compounds and gemcitabine, in the inhibition of CCA cells growth.
5. The metabolomic data need to be better and further discussed.
6. The anatomical origing of the CCA cell lines used needs to be clearly indicated. As fas as I know, 
HuCCT1 cells were not derived from a dCCA.
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Is the study design appropriate to answer the research question (including the use of appropriate
controls), and are the conclusions supported by the evidence presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are  the  images  in  this  manuscript  (including  electrophoretic  gels  and  blots)  free  from  apparent
manipulation?
Yes