Targeted extracellular degradation of LRP8 promotes ferroptosis in cancer cells

Name: Verified Rigor Record — Targeted extracellular degradation of LRP8 promotes ferroptosis in cancer cells
Item: Targeted extracellular degradation of LRP8 promotes ferroptosis in cancer cells
Rating: 71
Author: Αlpha¹

Zhao, F.; Inague, A.; Peters-Clarke, T. M.; Chen, Y.; Ganjave, S. D.; Zhang, Y.; Miao, K.; Yao, Z.; Wu, Y.; Seto, M. K. C.; Leung, K. K.; Olzmann, J.; Wells, J. A.

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Αlpha¹ Rigor Review

Rigor Review Verified

Critical

High-priority

Action items to resolve · Critical / High

Confidence: highEngine: 7.6.0Source: full text

Not verified in this report

No reported statistical tests were found to recompute.

This Alpha1 Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

The paper presents a well-motivated preclinical study with a strong scientific premise, detailed methods, and adequate controls. However, it has major transparency gaps: no data or code sharing, no cell line authentication or mycoplasma testing, and incomplete statistical reporting (no exact p-values or effect sizes). Several study design elements (randomization, blinding, power analysis) are not reported.

Three independent reviewers assessed the full manuscript; all eight rigor dimensions were evaluated. Analysis is based on the published paper, not a pre-submission draft. The statistics component found no recomputable tests (no test statistic + df or effect + CI reported), so mathematical plausibility was not assessed beyond what is stated. Cell-line sex, authentication, and mycoplasma testing were scored as applicable, leading to divergence on biological variables (one reviewer rated N/A, two rated warn). The copyedit pass flagged 16 minor issues.

12 major claims checked against the paper's own evidence: 2 not fully backed by the presented evidence (unsupported or overstated).

overstatedDiscussionReviewer 1
Extracellular degradation of LRP8 offers a safer and more selective strategy to modulate ferroptosis than direct GPX4 inhibition.
The paper demonstrates safety advantages only at the conceptual level and does not provide in vivo data comparing toxicity or selectivity to GPX4 inhibitors. The claim is extrapolated from in vitro cell line data and is not yet supported by direct evidence.
Evidence: In vitro data show LRP8 degradation enhances ferroptosis sensitivity in cancer cell lines. The discussion cites known liabilities of GPX4 inhibitors (kidney toxicity) but provides no experimental comparison. No in vivo toxicity or selectivity data are presented.
“Our findings suggest that extracellular targeting of LRP8 may offer a safer and more selective strategy to modulate ferroptosis, circumventing the liabilities associated with direct GPX4 inhibition.”
overstatedDiscussionReviewer 3
Extracellular targeting of LRP8 may offer a safer and more selective strategy to modulate ferroptosis than direct GPX4 inhibition
The claim is discussed as a potential advantage but is not directly tested in the paper; no in vivo toxicity or selectivity comparisons are performed. The paper proposes a rationale but provides no experimental evidence for safety.
Evidence: Discussion paragraph 2 describes theoretical advantages.
“Our findings suggest that extracellular targeting of LRP8 may offer a safer and more selective strategy to modulate ferroptosis, circumventing the liabilities associated with direct GPX4 inhibition.”
partialResults, final paragraphReviewer 3
Targeted extracellular degradation of LRP8 represents a generalizable strategy to potentiate ferroptosis across tumor cell types
The strategy was demonstrated in four cell lines (MDA-MB-231, HCC1143, Kelly, HT-1080), which suggests generalizability but is limited to in vitro cancer cell lines; in vivo validation is not provided.
Evidence: Degradation and ferroptosis sensitization were shown in MDA-MB-231, HCC1143, Kelly, and HT-1080 cells.
“These results establish LRP8 degradation as a generalizable strategy to potentiate ferroptosis across tumor cell types.”
supportedResults, Sections 'LRP8 degradation reduces selenoprotein levels' and 'LRP8 degradation sensitizes tumor cells to ferroptosis'Reviewer 1
Targeted degradation of LRP8 by KineTACs reduces GPX4 abundance and sensitizes cancer cells to ferroptosis.
The paper provides direct evidence from western blots showing reduced GPX4 levels after KineTAC treatment and cell viability/lipid peroxidation assays showing sensitization to ferroptosis inducers, replicated across multiple cell lines.
Evidence: Western blot data (Figures 4A–D) show reduced GPX4 levels after KineTAC treatment; cell viability and lipid peroxidation assays (Figures 5A–I) show enhanced sensitivity to RSL3, IKE, and other ferroptosis inducers, with rescue by ferrostatin-1.
“Both treatments reduced GPX4 abundance, although KineTAC2 was less effective... All KineTAC variants markedly sensitized cells to the covalent GPX4 inhibitor RSL3.”
supportedResults, Section 'KineTACs efficiently degrade LRP8'Reviewer 1
KineTAC-mediated degradation is selective and requires the CXCL12 arm for lysosomal degradation.
The paper shows that monovalent antibodies do not degrade LRP8, and degradation is blocked by Bafilomycin A1 but not by MG132 or Cytochalasin D, indicating lysosomal pathway dependency. Proteomics shows LRP8 is the most downregulated protein.
Evidence: Figure 3A–D (no degradation with monovalent antibodies), Figure 3E–G (inhibitor studies), and Figure 4E–G (proteomics showing LRP8 as top hit) support the claim.
“Monovalent LRP8 antibodies had no effect, indicating that degradation requires the CXCL12 arm for induced proximity. LRP8 degradation was blocked by the lysosomal V-ATPase inhibitor, Bafilomycin A1, but not by the proteasome inhibitor MG132 or the macropinocytosis inhibitor Cytochalasin D.”
supportedResults, Section 'LRP8 degradation reduces selenoprotein levels'Reviewer 1
LRP8 degradation impairs selenium uptake and reduces selenoprotein translation, which is rescued by inorganic selenium.
The paper shows that selenium supplementation (sodium selenite or L-selenocystine) restores GPX4 levels in KineTAC-treated cells, and proteomics confirms rescue of multiple selenoproteins.
Evidence: Figure 4C–D (rescue of GPX4 by selenium), Figure 4H–I (proteomics rescue), and Figure S7 (supplementary proteomics data).
“Supplementation with sodium selenite or L-selenocystine restored GPX4 levels regardless of LRP8 degradation, indicating that reduced selenoprotein level arises from impaired selenium uptake.”
supportedResults, KineTACs efficiently degrade LRP8Reviewer 2
KineTAC1 (CXCL12-203F1) robustly degrades LRP8 in TNBC cells.
The claim is backed by western blot data showing LRP8 degradation within 24 hours at concentrations as low as 2 nM.
Evidence: Western blot images and quantification (Figures 3B-C, F), flow cytometry (Figure 3E), and proteomics data.
“KineTAC1 induced robust LRP8 degradation within 24 hours, with activity detectable at concentrations as low as 2 nM”
supportedResults, LRP8 degradation reduces selenoprotein levelsReviewer 2
LRP8 degradation reduces GPX4 and other selenoprotein levels.
Western blot and proteomics data show GPX4 and other selenoprotein downregulation upon LRP8 degradation, with rescue by selenium supplementation.
Evidence: Western blots (Figure 4A-D) and whole-cell proteomics (Figure 4F-G).
“Both treatments reduced GPX4 abundance...”
supportedResults, LRP8 degradation sensitizes tumor cells to ferroptosisReviewer 2
KineTAC-mediated LRP8 degradation sensitizes cancer cells to ferroptosis.
Cell viability assays, lipid peroxidation measurements, and live-cell imaging show enhanced sensitivity to multiple ferroptosis inducers (RSL3, IKE, ML162) with rescue by Fer-1 in multiple cell lines.
Evidence: CellTiter-Glo viability assays (Figure 5A-F), BODIPY C11 lipid peroxidation flow cytometry (Figure 5G-H), Incucyte live-cell death imaging.
“All KineTAC variants markedly sensitized cells to the covalent GPX4 inhibitor RSL3”
supportedResults, LRP8 degradation reduces selenoprotein levels; DiscussionReviewer 2
LRP8 degradation is a selective and potentially safer way to modulate ferroptosis compared to direct GPX4 inhibition.
The paper shows that KineTAC treatment downregulates LRP8 selectively (most significant in proteomics) and spares normal tissues that depend on GPX4. The claim is supported by selectivity data and the discussion of systemic GPX4 inhibitor liabilities, though the statement is partially a forward-looking conclusion.
Evidence: Proteomics (Fig 4F), discussion of GPX4 inhibitor limitations.
“LRP8 was the most significantly downregulated protein following KineTAC1 and tKineTAC2 treatment, underscoring the selectivity of KineTAC-mediated extracellular protein degradation”
supportedResults, 'LRP8 degradation reduces selenoprotein levels'Reviewer 3
LRP8 degradation reduces selenoprotein levels, including GPX4
The paper provides direct western blot evidence showing LRP8 degradation reduces GPX4 and other selenoproteins, with selenium supplementation rescuing the phenotype.
Evidence: Western blot data (Figures 4A-D) and proteomics (Figures 4E-H) show reduction in GPX4 and other selenoproteins upon KineTAC treatment, with rescue by selenocystine/selenite.
“KineTAC1 efficiently degraded LRP8, whereas KineTAC2 was less potent and only effective at 50 nM. Both treatments reduced GPX4 abundance.”
supportedResults, 'LRP8 degradation sensitizes tumor cells to ferroptosis'Reviewer 3
LRP8 degradation sensitizes cancer cells to ferroptosis
Multiple ferroptosis inducers (RSL3, ML162, ML210, IKE) and cell types were tested, with lipid peroxidation and cell viability assays confirming sensitization, rescued by Fer-1.
Evidence: CellTiter-Glo viability, BODIPY C11 lipid peroxidation, and Incucyte live-cell death assays in HCC1143 and Kelly cells (Figures 5A-H).
“All KineTAC variants markedly sensitized cells to the covalent GPX4 inhibitor RSL3, and this effect was fully rescued by the radical-trapping antioxidant ferrostatin-1 (Fer-1)”

Rigor

Eight Dimensions2 pass · 4 warn · 1 fail

12 major claims2 overstated1 partial9 supported

16 copyedit issues flagged: mostly typo, consistency, clarity.

Checked 57 references: 55 verified — 2 not checked.

Reproducibility

1 data/code link checked; 1 live.

datahttps://alphafoldserver.com/LIVEHTTP 200
Resolves, but the content could not be matched to the paper.

Alpha¹ Rigor Action ItemsFinal pass before journal submission

The published paper has significant transparency gaps (no data/code repository, no cell line authentication/mycoplasma testing, incomplete statistics) that an informed reader should weigh critically. An erratum adding a data availability statement and depositing proteomics data to a public repository would address the most serious gap. Independent re-analysis of key conclusions (LRP8 degradation and ferroptosis sensitization) would strengthen confidence given the missing raw data and incomplete reporting of exact p-values and effect sizes.

1.
HIGHdata code
Add a Data Availability Statement (new section before Acknowledgments) stating that raw proteomics data have been deposited in a public repository (e.g., PRIDE/ProteomeXchange) and providing the accession number.
A data-driven proteomics study without a data availability statement fails a core transparency criterion and would be rejected by most journals.
2.
HIGHdata code
Deposit whole-cell proteomics raw data (DIA .raw and .d files) and processed output to a public repository (e.g., PRIDE) and include the accession number in the manuscript.
Without repository deposition, the key proteomics findings cannot be independently verified, undermining reproducibility.
3.
HIGHdata code
Upload custom analysis code (R scripts for Limma differential analysis, data visualization scripts) to a public repository (e.g., GitHub, Zenodo) with a permanent link or DOI and cite it in the manuscript.
Code sharing is essential for computational reproducibility; its absence is a material reporting gap.
4.
HIGHreporting
Report exact p-values (e.g., p = 0.023) for all key comparisons (degradation, SEPP1 uptake, lipid peroxidation, cell death) instead of threshold-only statements or asterisks.
Threshold-only p-values underinform readers about the strength of evidence and violate standard reporting norms (e.g., APA, ICMJE).
5.
HIGHreporting
Report effect sizes (e.g., fold change, Cohen's d, or mean difference) with 95% confidence intervals for each key comparison.
Effect sizes and CIs convey precision and magnitude, which p-values alone do not.
6.
HIGHrigor
Add a statement on cell line authentication (STR profiling) and mycoplasma testing to the Materials and Methods (Cell lines section).
Standard cell-line quality controls are expected; their absence raises concerns about cell line identity and contamination.
7.
HIGHrigor
Report the sex of each cell line (e.g., MDA-MB-231: female; HCC1143: female; Kelly: female; HT-1080: male) in the Materials and Methods, or justify why sex is not relevant.
Sex is a biological variable that can influence ferroptosis responses; omitting it limits interpretability.
8.
HIGHreporting
Clarify whether replicates are biological (independent cultures) or technical (repeated measurements from the same culture) for every experiment, and report the exact n per group.
Distinguishing biological from technical replicates is critical for correct error estimation and statistical inference.
9.
HIGHstatistics
Add a section on statistical assumptions (normality, homoscedasticity) tested for parametric tests, or state that non-parametric tests were used if assumptions could not be verified.
Failure to verify assumptions can invalidate p-values and conclusions drawn from parametric tests.
10.
HIGHreporting
Temper the claim that 'Extracellular degradation of LRP8 offers a safer and more selective strategy to modulate ferroptosis than direct GPX4 inhibition' (Discussion, paragraph 2) to reflect that safety and selectivity were not directly tested (no in vivo toxicity or selectivity comparisons).
The claim_audit flagged this as overstated; readers should not infer demonstrated safety from in vitro cell line data alone.
11.
HIGHreporting
Temper the claim that 'Extracellular targeting of LRP8 may offer a safer and more selective strategy to modulate ferroptosis than direct GPX4 inhibition' (Introduction) to indicate this is a rationale, not an experimental finding.
The claim_audit flagged this as overstated; it is presented as a finding rather than a hypothesis.
12.
MEDIUMrigor
Add a statement that no randomization or blinding was performed (since this is in vitro work) to the Materials and Methods for transparency.
Acknowledging the absence of randomization and blinding is more transparent than omitting the topic entirely.
13.
MEDIUMrigor
Add a sample size justification (power analysis) or state that sample sizes were based on prior similar studies.
A priori power analysis helps readers assess whether experiments have adequate sensitivity to detect meaningful effects.
14.
MEDIUMreporting
Consider including individual data points (dot plots) overlaid on bar graphs for key quantitative results (degradation efficiency, BODIPY shift, cell death) to improve data transparency.
Bar graphs alone obscure the underlying distribution and can hide outliers or small sample sizes.
15.
MEDIUMother
Fix the 16 copyedit issues flagged by the copyedit pass: correct typos (e.g., 'Unbounded' -> 'Unbound'), duplicate catalog numbers ('L36003 L36003'), inconsistent inhibitor names ('Bafilomycin A' -> 'Bafilomycin A1'), missing prepositions, and extraneous parentheses.
Minor errors reduce the manuscript's perceived quality and can confuse readers.

Full text (43,267 chars)Analyzed: Jul 6, 2026

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