Integrity Review Report: Butyrate Suppresses Glucose Metabolism of Colorectal Cancer Cells via GPR109a-AKT Signaling Pathway and Enhances Chemotherapy (Frontiers in Molecular Biosciences, 2021)

Academic fraud report · Geng Detector

Summary

This report assesses the article by Geng et al. (DOI: 10.3389/fmolb.2021.634874) and rates it as highly suspicious (orange). Three issues are judged severe (red/orange). First, the Results narrative reports suspiciously precise whole-number metabolite decreases (lactate ~60%, R5P ~70%, acetyl-CoA ~58%, NADPH ~60%) and clean half-unit fold-changes after SC79 rescue (e.g., 5x, 3.5x, 4.5x, 2.5x), which is atypical for triplicate LC-MS/MS measurements. Second, the CCK-8 protocol states absorbance is read at 590 nm, whereas WST-8 formazan is routinely read at ~450 nm, raising a fundamental methodological inconsistency. Third, the Western blot Methods text contains isolated tokens '274' and '275' consistent with residual page/line numbers from copy-pasted protocols, and the cell line name oscillates between 'LoVo' and 'LOVO'. The paper also inserts COVID-19 commentary that is tangential to the mechanistic focus. Image-level duplication could not be assessed because no figures were available. Verdict: highly suspect pending raw-data verification.

Verdict

🟠 Highly suspicious. Multiple severe issues were identified from the text alone, including a wavelength error incompatible with CCK-8 chemistry and implausibly tidy quantitative results. Pixel-level image analysis was not possible because figures were not supplied.

Key findings

Suspect quantitative aesthetics in Results (🔴): Reported metabolite decreases (lactate ~60%, R5P ~70%, acetyl-CoA ~58%, NADPH ~60%) and SC79 rescue fold-changes (e.g., 5x and 3.5x for GLUT1; 4.5x and 2.5x for G6PD) are unrealistically clean for triplicate LC-MS/MS data.
Incompatible CCK-8 detection wavelength (🔴): Methods specify absorbance at 590 nm, but CCK-8 (WST-8) formazan is read at ~450 nm; 590 nm is commonly associated with dissolved MTT formazan, not WST-8.
Ghost numbers in Methods (🟠): Western blot buffer recipe contains stray tokens "274" and "275" between reagent terms (e.g., "0.5% deoxycholic acid, 274 and 0.1% SDS..."; "5 μg/ml 275 leupeptin"), consistent with residual line/page numbers from a copy-pasted protocol.
Cell-line naming inconsistency (🟡): Within the same paragraphs the line is written as both "LoVo" and "LOVO" (HCT116 and LoVo / HCT116 and LOVO; BrdU section likewise), suggesting patched-together records.
Topic drift / COVID-19 padding (🟡): Introduction and Conclusion contain extended COVID-19 discussion unrelated to butyrate/GPR109a-AKT mechanism, suggesting topical packaging.
Image forensics: not assessable — figures (Figs 1–5) were not available for pixel-level inspection.

Evidence highlights

Quantitative claims (Results): lactate ≈60%, R5P ≈70%, acetyl-CoA ≈58%, NADPH ≈60% reductions; SC79 rescues GLUT1 membrane levels by "5 times" and "3.5 times"; G6PD protein increases by "4.5 times" and "2.5 times"; apoptosis drops from 9% to 2.5%. Values are quoted directly from the text.
Methodological inconsistency (Cell Viability Assay): "...recorded at 590 nm" for CCK-8 (Dojindo); WST-8 formazan absorbance maximum is ~450 nm; 590 nm is atypical for CCK-8 and more consistent with legacy MTT protocols.
Protocol-text artifacts (Western Blotting): "0.5% deoxycholic acid, 274 and 0.1% SDS..." and "(1 mM PMSF, 5 μg/ml 275 leupeptin...").
Nomenclature drift: "HCT116 and LoVo cells" immediately followed by "HCT116 and LOVO cells"; repeated in the BrdU paragraph.
Topic drift: Introductory and concluding paragraphs discuss COVID-19 severity in cancer patients undergoing immunotherapy, not butyrate metabolism.

Notes

Confidence is high for the wavelength and stray-number issues, as both are textual facts in the published article. Confidence is moderate for the "too-clean" data claim, because exceptionally clean numbers could in principle arise from normalization/rounding but are atypical for biological triplicates.
The image-related portion of this report (suspected reuse or splicing of Western blot, flow cytometry, or microscopy panels) cannot be verified from the materials supplied; a figure-level audit is required.
DOI 10.3389/fmolb.2021.634874 should be preserved in any downstream citation or PubPeer entry.
This is a translation/synthesis of a third-party detection report; final determination of misconduct requires institutional investigation and raw-data inspection (e.g., original 450 nm plate-reader exports, uncropped blots, and raw MS files).