PONE-D-19-16594

The impact of short-term machine perfusion on the risk of cancer recurrence after rat liver transplantation with donors after circulatory death

PLOS ONE

Dear Dr Oldani,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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Specifically, Authors should address issues pertaining heterogeneity of HCC cell lines and how their finding relate to this phenotypic feature.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Oldani G. and co authors, in the current paper, examined the impact of hypothermic and normothermic ex vivo liver perfusions on JM-1 neoplastic cells growth in transplanted rat liver. In comparison with fresh transplanted rats, both methods of “ex vivo” perfusion determined increase of HCC growth, thus suggesting a role in ischemia-reperfusion injury in supporting tumor proliferation and spreading.

Comments

1) The results of the study were based on the use of JM-1 line only. Several other HCC cell lines are available and, on the other hand, HCC in human denotes several phenotypic differences between subjects. For all the above, the authors should comment the limits of the extrapolation of these results in the setting of HCC in human liver transplantation.

2) Since three groups were included in the study, ANOVA should be the appropriate test for statistical comparison.

3) The study is mainly observational and putative mechanisms relating ischemia-reperfusion injury to increase tumor proliferation should be at list mentioned in discussion. In my opinion, this line of research would benefit in the future by testing HCC growth and spreading genes in “in vitro” easily adaptable systems.

Reviewer #2: This is a very interesting study and the findings are very robust.

The group performed DDLT using DCD grafts in rats compared with fresh liver grafts. The DCD grafts were divided into two groups using HOPE or NORMO as the machine perfusion. While the findings of transaminases post-machine perfusion was somewhat expected, I find it difficult to understand why there are more peritoneal metastasis in the study, and it was particularly related to the tumor size.

The authors tried to induce tumour growth by injecting the designated tumour cells with HCCs via portal vein after repercussion and monitor for tumor growth. However, how does that translate into the distribution of tumours in different parts of the liver was not explained. More importantly, I am curious to know how these larger tumours were able to develop into peritoneal carcinomatosis within 28 days and the details of this data was not available in the results section.

Overall, it is an interesting study, proving the concept that the ischaemic environment promotes tumour progression but the actual pathological process involved, particularly from the immunological aspects was not clear.

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Reviewer #1: No

Reviewer #2: No

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The impact of short-term machine perfusion on the risk of cancer recurrence after rat liver transplantation with donors after circulatory death

PONE-D-19-16594R1

Dear Dr. Oldani,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Ezio Laconi, MD, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: (No Response)

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: (No Response)

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: (No Response)

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: (No Response)

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: The revision has addressed all the issues that I have raised.

However, the authors should still try to explain how the tumours are distributed after being injected into the Rat's liver. Albeit the liver of the rats are small, how this end up in the peritoneum as carcinomatosis is not explained.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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Reviewer #1: No

Reviewer #2: No