LPIN1 Induces Gefitinib Resistance in EGFR Inhibitor-Resistant Non-Small Cell Lung Cancer Cells

Round 1

Reviewer 1 Report

In this study, CHO et al. focus on the resistance role of LPIN1 in Non Small Lung Cancers expressing mutated-EGFR. The manuscript submitted here describes series of results clearly presented. They use successfully both in vitro studies and in vivo xenograft approaches. The authors observed that LPIN1 knockdown increased gefitinib sensitivity in drug-resistant H1650 NSCLC cells, as well as patient-derived YL05 lung cancer cells. Contrary to TKI-sensitive cells, LPIN1 expression was induced by gefitinib treatment in TKI-resistant cells, followed by activation of PKC and NFkB pathways. Additionally, an increased production of lipid droplets toward a lipogenic state associated to drug resistance was induced by LPIN1. Using in vivo tumorigenesis approach, authors identified that both pharmaceutical and shRNA-mediated inhibition of LPIN1 diminished tumor growth.

The quality of writing was good. Immunoblot quality was fine and the technical merit was very good. Results are elegantly shown. Technical terms were rigorously and well detailled.

Overall, the study is within the scope of Cancers journal.

minor correction: Figure 1F: authors should change siLPN1 - - to + + legends in two last columns

Author Response

Response to Reviewers

 

Reviewer 1:

In this study, CHO et al. focus on the resistance role of LPIN1 in Non-Small Lung Cancers expressing mutated-EGFR. The manuscript submitted here describes series of results clearly presented. They use successfully both in vitro studies and in vivo xenograft approaches. The authors observed that LPIN1 knockdown increased gefitinib sensitivity in drug-resistant H1650 NSCLC cells, as well as patient-derived YL05 lung cancer cells. Contrary to TKI-sensitive cells, LPIN1 expression was induced by gefitinib treatment in TKI-resistant cells, followed by activation of PKC and NF-kB pathways. Additionally, an increased production of lipid droplets toward a lipogenic state associated to drug resistance was induced by LPIN1. Using in vivo tumorigenesis approach, authors identified that both pharmaceutical and shRNA-mediated inhibition of LPIN1 diminished tumor growth.

The quality of writing was good. Immunoblot quality was fine and the technical merit was very good. Results are elegantly shown. Technical terms were rigorously and well detailed.

Overall, the study is within the scope of Cancers journal.

 

Comment:

 

Point 1. Minor correction: Figure 1F: authors should change siLPN1 - - to + + legends in two last columns

Response: Thank you for your positive response and for pointing out the error. We corrected the legend in Figure 1.

Reviewer 2 Report

This is a decent piece of work by Cho et al, where they studied the role of LPIN in inducing resistance to Gefitinib in lung cancer. The article is well written and nicely organized.

Comments:

1. It is difficult to understand which whether authors are trying to understand upfront resistance or acquired resistance? Line 50-51 says it is crucial to understand mechanism of resistance in patiemts with relapse. The author should clearly state what they are trying to address. Because the resistant cell line was used in the study, the study is focused to understand upfront resistance rather acquired resistance. Authors should clarify.
2. It is good to have validations in more than one cell line models, Unfortunately, only 1 resistant and 1 sensitive cell lines was used in this study. Authors should have IC50 curves of both -resistant and cell lines in supplementary figures.
3. Correction required in Figure 1F, results mentioned in text is not in concordance with Figure. Might be some labelling errors.
4. For all combination studies performed in the paper in resistant line – the concentration of Gefitinb used in 10uM or 5uM. Do authors really think this high dose in clinically achievable in patients. Did authors try dosing resistant cells al lower dose in combination with LPIN1 and/or LPC inhibition?
5. Do resistant cells really need Gefitinib treatment, or they have other pathways like LPIN1 mediated pathways as new vulnerabilities to sustain cell proliferation?
6. It seems data in Figures 3A and 3D is not statistically significant. Please clarify
7. Please provide details on PDCs YL05. Was this patient a responder to TKIs ? non-responder? Patient with replaced tumor? Or naïve without any therapy? This will help to understand if the selection of patients was relevant to study or not?
8. Please clarify for all experiment – if the experiments are done in technical or biological replicates? Like Figure 1C, 5B, 5C and others.
9. Please simplify many complicated statements which changes the meaning or difficult to follow. For example, 284-286, 390-393
10. Any comment on the off targets of LPIN1 and PKC inhibitors used in this study?

Author Response

Please see the attachment.

Author Response File: Author Response.docx