Slug enhances invasion ability of pancreatic cancer cells through upregulation of matrix metalloproteinase-9 and actin cytoskeleton remodeling
Zhang K, Chen D, Jiao X, Zhang S, Liu X, Cao J, Wu L, Wang D.
- DOI
- 10.1038/labinvest.2010.201
- Record issued
- 2026-08-06
- Engine
- 7.15.0
- Exported
- 2026-09-20
Prepared by Alpha1. This document is confidential: it is intended for the recipient it was shared with and must not be redistributed. The live record at alpha1science.com/verify/975285ad-8c12-496d-b45f-03bf30db2955 is authoritative.
How this rating was calculated
- IntegrityIntegrity concern ×7−3.5★
- ClaimsOverstated claim ×3−1.5★
- StatisticsImpossible or misreported statistic−1★
- StatisticsStatistic did not reproduce−0.5★
- ReportingBiological variables not met−0.5★
- ReportingData & code availability not met−0.5★
- CopyeditManuscript needs significant editing−0.5★
- ReportingStudy design partially met−0.25★
- ReportingEthical approvals partially met−0.25★
- ReportingKey resources partially met−0.25★
- ReportingStatistical analysis partially met−0.25★
- ReportingReporting transparency partially met−0.25★
A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.
- No data or code availability links were detected to verify.
- 01Significance claim does not survive recomputationdemonstrable
Chi-square test for association between E-cadherin expression and nodal metastasis (Table 1)
- 02Reported statistic does not recompute
Chi-square test for association between Slug expression and nodal metastasis (Table 1)
- 03Biological variables not reported
Biological variables are inadequately reported: human patient demographics (age, sex) are absent, animal housing conditions are vague, and single-sex animal use is not justified.
“Female C57BL/6 mice at 6–8 weeks old were obtained from Qingdao Medical college, Qingdao University”
Methods - 04Data and code not shared
No data availability statement or data/code sharing is provided. The paper does not mention any repository deposit, accession numbers, or code repository.
- 05Internal contradictions in the reported numbers
In Table 2 the Slug column totals (18+17=35 for 'Positive' and 7+18=25 for 'Negative') directly contradict the stated group sizes (Positive n=41, Negative n=19) given in the same table header; the reported P=0.0034 for the Slug-MMP-9 correlation does not reproduce from either reading of the displayed counts.
Slug | Positive ( n =41) | Negative ( n =19) | | MMP-9 | Positive ( n =25) | 18 | 7 | | Negative ( n =35) | 17 | 18
Table 2reviewer’s wording - 06Internal contradictions in the reported numbers
In Table 2, the Slug-positive column sums to 35 and the Slug-negative column sums to 25, but the table states n=41 and n=19, respectively. This internal inconsistency undermines the reported correlation p-values.
“Positive ( n =41) | Negative ( n =19) | | | MMP-9 | | | 0.0034 | | Positive ( n =25) | 18 | 7 | | | Negative ( n =35) | 17 | 18”
Table 2
3 further findings of this severity or below — every one is in the sections below, filed under its error type.
This Kaimen Rigor review uses Kaimen 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 has a clear scientific premise and adequate controls for experiments, but lacks many fundamental rigor elements: no randomization, blinding, power analysis, or independent replication; human cohort demographics are missing; key resources lack catalog numbers and cell line authentication; statistical reporting contains inconsistencies in Table 2 that undermine the reported p-values; no data or code availability; and several conclusions are overstated relative to the evidence.
All eight dimensions were applicable. The three independent reviewer runs agreed on the overall pattern but diverged on the severity of study design, ethical approvals, key resources, statistical analysis, and reporting transparency; the synthesized statuses were determined by applying the scoring rules to the checklist evidence, which sometimes corrected overly lenient ratings.
Numerical inconsistencies
2 findings · worst highValues that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.
- Reported statistics do not recomputeRecomputed
- Internal contradictions in the reported numbersAssessed
Recomputed 7 tests: 5 consistent, 2 inconsistent (1 change significance at p<.05); 7 via agent-written checks.
- INCONSISTENTreported p < .010 · recomputed p = .018Reviewers 1, 3Chi-square test for association between Slug expression and nodal metastasis (Table 1)How we recomputed it: pChi2x2(19,15,22,4)
- CONSISTENTreported p < .010 · recomputed p = .006Reviewers 1, 3Chi-square test for association between MMP-9 expression and nodal metastasis (Table 1)How we recomputed it: pChi2x2(9,25,16,10)
- CONSISTENTreported p > .050 · recomputed p = .109Reviewer 1Chi-square test for correlation between Slug and E-cadherin expression (Table 2)How we recomputed it: pChi2x2(11,13,24,12)
- CONSISTENTreported p = .057 · recomputed p = .109Reviewer 3Slug vs E-cadherin association, Table 2, printed cell countsHow we recomputed it: pChi2x2(11,13,24,12)
- CONSISTENTreported p < .050 · recomputed p = <.001Reviewer 3MMP-9 expression vs nervous invasion, Table 1How we recomputed it: pChi2x2(7,25,18,10)
- CONSISTENTreported p > .050 · recomputed p = .630Reviewer 3Slug expression vs nervous invasion, Table 1How we recomputed it: pChi2x2(21,11,20,8)
- mediuminternal contradictionIn Table 2 the Slug column totals (18+17=35 for 'Positive' and 7+18=25 for 'Negative') directly contradict the stated group sizes (Positive n=41, Negative n=19) given in the same table header; the reported P=0.0034 for the Slug-MMP-9 correlation does not reproduce from either reading of the displayed counts.
Slug | Positive ( n =41) | Negative ( n =19) | | MMP-9 | Positive ( n =25) | 18 | 7 | | Negative ( n =35) | 17 | 18
Table 2reviewer’s wording - mediuminternal contradictionIn Table 2, the Slug-positive column sums to 35 and the Slug-negative column sums to 25, but the table states n=41 and n=19, respectively. This internal inconsistency undermines the reported correlation p-values.
“Positive ( n =41) | Negative ( n =19) | | | MMP-9 | | | 0.0034 | | Positive ( n =25) | 18 | 7 | | | Negative ( n =35) | 17 | 18”
Table 2 - lowinternal contradictionThe Animal Studies section describes 'Female C57BL/6 mice' but subsequently refers to them as 'nude mice'; while C57BL/6 nude mice exist, the nomenclature is inconsistent and the strain background is ambiguous.
Female C57BL/6 mice at 6–8 weeks old were obtained from Qingdao Medical college, Qingdao University for tumor implantation. All animals were maintained in a sterile environment and cared for within the laboratory animal regulations of the Ministry of Science and Technology of the People's Republic of China. Full details of the study approval by the ethics committee at the affiliated hospital of medical college, Qingdao University. We inoculated the nude mice with cell samples as described previously.
Methodsreviewer’s wording - lowinternal contradictionTable 3's title states n=10 while the groups are labeled n=12 and all cell counts (e.g., 8+4=12 for PANC-1 hepatic) sum to 12, so the (n=10) header appears to be a typo.
“Table 3 Slug promoted in vivo tumor hepatic metastasis and lymph node invasion ( n =10) Groups ( n =12)”
Table 3 - lowinternal contradictionTable 3 caption says n=10 while the table header and Results text indicate n=12 per group.
“Table 3 Slug promoted in vivo tumor hepatic metastasis and lymph node invasion ( n =10) Groups ( n =12)”
Table 3
Overstated conclusions
3 findings · worst criticalConclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.
- Significance claim flips when recomputedRecomputed
- Conclusions overstated beyond the evidenceAssessed
- Conclusions only partially backed by the presented evidenceAssessed
- SIGNIFICANCE OVERSTATEDINCONSISTENTreported p < .010 · recomputed p = .071Reviewers 1, 3Chi-square test for association between E-cadherin expression and nodal metastasis (Table 1)Reported as statistically significant, but recomputing from the paper’s own numbers gives p ≥ 0.05 — the result may not be significant as claimed.How we recomputed it: pChi2x2(17,17,7,19)
12 major claims checked against the paper's own evidence: 3 not fully backed by the presented evidence (unsupported or overstated).
- overstatedReviewer 1Slug transports MMP-9 to the anterior extremity of filopodia via F-actin networks.The claim overstates the evidence; the study shows co-localization of MMP-9 and F-actin in filopodia, but does not demonstrate direct transport or a causal mechanism for transport.Evidence: Figure 5: double immunofluorescence shows MMP-9 and F-actin co-localize in filopodia of Slug-transfected cells.
MMP-9 and F-actin are primarily located in the anterior extremity of the filopodia... suggesting Slug might transport MMP-9 via F-actin networks
Discussionreviewer’s wording - overstatedReviewer 2Slug may serve as a marker for predicting malignancy of pancreatic cancer after surgery.This is a correlative IHC finding in 60 patients with no prospective validation, sensitivity/specificity analysis, or multivariate adjustment, so the predictive-marker claim reaches beyond the evidence.Evidence: Only the IHC association with nodal metastasis in Table 1; no predictive performance analysis.
“Slug may serve as a marker for the prediction of the malignancy of pancreatic cancer after operation.”
Discussion ¶2 - overstatedReviewer 3The present study is the first to explore the relationship between Slug and MMP-9 in pancreatic cancer.The paper provides evidence for an association and mechanism but does not provide any literature-search basis to substantiate the 'for the first time' priority claim.Evidence: No systematic literature review or novelty declaration is provided.
“The present study for the first time has explored the relationship between Slug and MMP-9 in pancreatic cancer and clarified the novel mechanism.”
Discussion - partialReviewer 2There is a significant correlation between Slug and MMP-9 expression in pancreatic cancer tissue.The paper reports P=0.0034 for the Slug-MMP-9 correlation, but the supporting Table 2 has cell counts that do not sum to the stated group sizes and the p-value does not reproduce from the displayed numbers, so the correlation is not reliably substantiated by the presented data.Evidence: Table 2 Slug-MMP-9 cross-tabulation with P=0.0034; Slug column sums (35/25) contradict stated n (41/19).
“Statistically significant correlations were found between Slug and MMP-9 expression ( P <0.05).”
Table 2 - partialReviewer 3A significant correlation exists between Slug and MMP-9 expression.The paper reports p=0.0034, but Table 2's cell counts do not sum to the stated group sizes, so the correlation is not verifiable from the printed data.Evidence: Table 2 reports 0.0034 for the Slug–MMP-9 correlation.
“Statistically significant correlations were found between Slug and MMP-9 expression ( P <0.05).”
Results - partialReviewer 3There is no significant correlation between Slug and E-cadherin expression.The reported p=0.057 supports the conclusion directionally, but the same Table 2 inconsistency prevents full verification.Evidence: Table 2 reports 0.057 for the Slug–E-cadherin correlation.
“no significant correlation was observed between Slug and E-cadherin expression”
Abstract - supportedReviewer 1Slug expression is significantly associated with lymph node metastases in pancreatic cancer patients.The claim is supported by Table 1 data showing a significant chi-square test (P<0.01) for nodal metastasis vs. Slug expression.Evidence: Table 1: Nodal metastasis positive group: Slug+ 22, Slug- 4; negative group: Slug+ 19, Slug- 15; χ²=5.49, P<0.01.
Nodal metastasis... P <0.01
Table 1reviewer’s wording - supportedReviewer 1Slug expression is significantly correlated with MMP-9 expression but not with E-cadherin expression in pancreatic cancer.The claim is supported by Table 2 which shows a significant association between Slug and MMP-9 (P=0.0034) and no significant association between Slug and E-cadherin (P=0.057).Evidence: Table 2: MMP-9 vs. Slug: χ² test P=0.0034; E-cadherin vs. Slug: P=0.057.
Correlation between Slug expression and E-cadherin or MMP-9 expression... P 0.0034
Table 2reviewer’s wording - supportedReviewer 1Slug overexpression upregulates MMP-9 and promotes invasion and metastasis in PANC-1 cells.The claim is supported by multiple in vitro assays (RT-PCR, western blot, ELISA, zymography) showing increased MMP-9 expression and activity, and by invasion assays and in vivo xenograft showing increased metastasis.Evidence: Figures 2, 6, 7; Table 3: increased hepatic and lung metastasis in Slug-transfected group.
Slug overexpression upregulated MMP-9 at the mRNA and protein level... overexpression of Slug enhanced invasion in PANC-1 cells... Slug-transfected cells exhibited a highly invasive behavior
Resultsreviewer’s wording - supportedReviewer 1Slug promotes F-actin polymerization and filopodia formation in PANC-1 cells.The claim is supported by FCM showing increased intracellular F-actin and confocal microscopy showing filopodia formation and F-actin redistribution.Evidence: Figure 4: FCM shows 2.1-fold increase in F-actin; confocal microscopy shows F-actin redistribution in Slug-transfected cells.
the intracellular F-actin in Slug-transfected clones increased 2.1-fold... F-actin was polymerized in Slug-transfected clones
Resultsreviewer’s wording - supportedReviewer 2Slug, E-cadherin, and MMP-9 expression in pancreatic cancer tissue is significantly associated with lymph node metastases.Table 1 reports significant chi-square associations for all three markers with nodal metastasis (P<0.01), consistent with the claim.Evidence: Table 1 Nodal metastasis rows: Slug chi2=5.49 P<0.01; MMP-9 chi2=5.24 P<0.01; E-cadherin chi2=4.86 P<0.01.
“Slug, MMP-9, and E-cadherin expression was significantly associated with nodal metastases ( P <0.01, respectively”
Results - supportedReviewer 2Slug transfection significantly increases invasion and metastasis of PANC-1 cells in vitro and in an orthotopic mouse model, and upregulates and activates MMP-9.In vitro invasion counts (68.74±7.34 vs 117.16±8.45), zymography showing active 82-kDa MMP-9, and in vivo metastasis counts (10 liver, 6 lung in Slug-transfected vs fewer in controls) support the claim.Evidence: Cell Invasion Assays results; Gelatin Zymography; Table 3 in vivo metastasis counts.
“overexpression of Slug enhanced invasion in PANC-1 cells. The difference was statistically significant”
Results
Data authenticity concerns
2 findings · worst lowAn adversarial read for patterns associated with data that may not be genuine: results that look too clean, implausibly large effects, duplicated data or images, and methods that do not match the results reported.
- Methods and results do not matchAssessed
- Other integrity concernAssessed
7 integrity concerns flagged (0 high).
- lowotherSeveral self-reported chi-square statistics in Table 1, when converted with df=1, give p-values around 0.02-0.07 (e.g., Slug nodal chi-square=5.49 -> p~0.019, E-cadherin nodal chi-square=4.86 -> p~0.027), which are below 0.05 but not below the reported threshold of 0.01, suggesting the 'P<0.01' labels may be slightly overstated.
Nodal metastasis | Negative ( n =34) | 19 | 15 | | Positive ( n =26) | 22 | 4 | | ... | 5.49 | <0.01
Table 1reviewer’s wording - lowmethod result mismatchThe reported p=0.0034 for the Slug–MMP-9 correlation is not reproduced by Pearson chi-square on the printed table cell counts (approximate p=0.07), although the table's internal inconsistency makes the exact cause unclear.
“Statistically significant correlations were found between Slug and MMP-9 expression ( P <0.05).”
Table 2
Reporting gaps
7 findings · worst highRequired detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.
- Biological variables not reportedAssessed
- Data and code not sharedAssessed
- Statistical reporting gaps (tests, assumptions, effect sizes)Assessed
- Ethics/consent reporting incompleteAssessed
- Key resources under-identified (antibodies, cell lines, RRIDs)Assessed
- Reporting/transparency gapsAssessed
- Study-design details incomplete (controls, blinding, power)Assessed
Prior research on Slug, EMT, E-cadherin, and MMP-9 in pancreatic cancer is cited, including studies that found no relationship between Slug and E-cadherin. The rationale for investigating Slug's role in MMP-9 upregulation is clearly stated. Limitations of prior work are acknowledged (e.g., dependency on tissue/cell type), and the study aims to address these gaps.
“A recent study demonstrated that no relationship exists between Slug and E-cadherin in pancreatic cancer.”
“In this study, we aimed to examine the expression of Slug, E-cadherin, and MMP-9 in pancreatic cancer and to obtain further insight into the question of whether Slug promotes E-cadherin or MMP-9-induced EMT in pancreatic cancer.”
“the relationship between Slug transcription, Snail transcription, and E-cadherin is largely dependent on tissue and cell type.”
“Recent work in hepatocellular carcinoma, breast cancer, and esophageal squamous cell carcinoma suggests that the transcriptional factors Snail and Slug are important effectors of the process of invasiveness and tumorigenicity through regulation of the expression of E-cadherin.”
“The difference may be because of the limited number of patients or the evaluation the immunohistochemistry results.”
“Recent work in hepatocellular carcinoma, breast cancer, and esophageal squamous cell carcinoma suggests that the transcriptional factors Snail and Slug are important effectors of the process of invasiveness and tumorigenicity through regulation of the expression of E-cadherin.”
“In this study, we aimed to examine the expression of Slug, E-cadherin, and MMP-9 in pancreatic cancer and to obtain further insight into the question of whether Slug promotes E-cadherin or MMP-9-induced EMT in pancreatic cancer.”
“However, the relationship between Slug transcription, Snail transcription, and E-cadherin is largely dependent on tissue and cell type.”
For the interventional components, the paper reports replicate distinction (duplicate experiments repeated four times) and includes appropriate controls (mock, vector, BB94 inhibitor). However, randomization of subjects/samples, blinding of investigators, a priori power analysis, and outlier handling are not reported. Inclusion/exclusion criteria for the clinical samples are described (consecutive cases with available tissue). Independent replication is not reported.
“Individual experiments were done in duplicate and repeated four times.”
“Slug-transfected or mock-transfected or untreated PANC-1 cells were plated at a density of 5 × 10 4 /mm 2 in culture dishes”
“Between 1999 and 2009, 60 consecutive pancreatic adenocarcinoma (ordinary ductal carcinoma) specimens for which tissue was available for immunohistochemical staining were identified”
“Individual experiments were done in duplicate and repeated four times.”
“Individual experiments were done in duplicate and repeated four times.”
“The PANC-1 cells were transfected with 3 μ g of pcDNA3–Slug cDNA or control pcDNA3 vector as recently described using the Lipofectamine Plus reagent (Gibco BRL).”
For the animal study, sex (female), age (6-8 weeks), species/strain (C57BL/6), and source are reported, but housing conditions are only briefly mentioned ('sterile environment'). For the human cohort, no demographic details (age, sex, race/ethnicity) are provided. The use of only female mice is not justified. The cell line (PANC-1) is from ATCC, which is adequate.
“Female C57BL/6 mice at 6–8 weeks old were obtained from Qingdao Medical college, Qingdao University”
“All animals were maintained in a sterile environment and cared for within the laboratory animal regulations of the Ministry of Science and Technology of the People's Republic of China”
“Female C57BL/6 mice at 6–8 weeks old were obtained from Qingdao Medical college, Qingdao University”
“The PANC-1 cell line used in present study was obtained from ATCC”
“Female C57BL/6 mice at 6–8 weeks old were obtained from Qingdao Medical college, Qingdao University for tumor implantation.”
“The PANC-1 cell line used in present study was obtained from ATCC”
For human research, an ethics committee is named but no protocol number is given. The consent statement ('approved in written form by the patients studied') is ambiguous. For animal research, approval by the ethics committee is mentioned without a protocol number or specific IACUC name. Regulatory compliance with Chinese laboratory animal regulations is stated for animals, but no equivalent for human research (e.g., Declaration of Helsinki) is mentioned.
“All research involving human participants was approved in written form by the patients studied and the ethics committee at the affiliated hospital of medical college, Qingdao University.”
“Full details of the study approval by the ethics committee at the affiliated hospital of medical college, Qingdao University.”
“All animals were maintained in a sterile environment and cared for within the laboratory animal regulations of the Ministry of Science and Technology of the People's Republic of China”
“All research involving human participants was approved in written form by the patients studied and the ethics committee at the affiliated hospital of medical college, Qingdao University.”
“Full details of the study approval by the ethics committee at the affiliated hospital of medical college, Qingdao University.”
“cared for within the laboratory animal regulations of the Ministry of Science and Technology of the People's Republic of China”
“All research involving human participants was approved in written form by the patients studied and the ethics committee at the affiliated hospital of medical college, Qingdao University.”
“Full details of the study approval by the ethics committee at the affiliated hospital of medical college, Qingdao University.”
Antibodies are identified by vendor and dilution (Santa Cruz Biotechnology, 1:100) but without catalog numbers, clones, or validation citations; the PANC-1 cell line is named with source (ATCC) but no STR authentication; mycoplasma testing is absent. Mice, primer sequences, plasmids, kits, inhibitors, and software (SPSS13.0, Quantity One) are adequately identified.
“Slug (dilution at 1:100; Santa Cruz Biotechnology) or E-cadherin (dilution at 1:100; Santa Cruz Biotechnology), or MMP-9 (dilution at 1:100, Santa Cruz Biotechnology)”
“The PANC-1 cell line used in present study was obtained from ATCC”
“All statistical analyses were performed using SPSS13.0 software.”
“Tissue slides were immunohistochemically stained for Slug (dilution at 1:100; Santa Cruz Biotechnology) or E-cadherin (dilution at 1:100; Santa Cruz Biotechnology), or MMP-9 (dilution at 1:100, Santa Cruz Biotechnology)”
“The PANC-1 cell line used in present study was obtained from ATCC”
“All statistical analyses were performed using SPSS13.0 software.”
“Tissue slides were immunohistochemically stained for Slug (dilution at 1:100; Santa Cruz Biotechnology) or E-cadherin (dilution at 1:100; Santa Cruz Biotechnology), or MMP-9 (dilution at 1:100, Santa Cruz Biotechnology).”
“The PANC-1 cell line used in present study was obtained from ATCC”
“All statistical analyses were performed using SPSS13.0 software.”
The paper names the statistical tests used (ANOVA, Dunnett's t-test, Student's t-test, χ²). SPSS13.0 is identified. Data are presented as mean±s.d. with per-group n. However, test assumptions (normality, equal variance) are not verified. Effect sizes are not accompanied by confidence intervals. Many p-values are reported as '<0.05' or '<0.01' instead of exact values. No internal inconsistencies were detected in the reported numbers.
“Differences between various groups were assessed using ANOVA or Dunnett's t -test. A P -value of <0.05 was considered to indicate statistical significance.”
“Slug, MMP-9, and E-cadherin expression was significantly associated with nodal metastases ( P <0.01, respectively”
“Differences between various groups were assessed using ANOVA or Dunnett's t -test.”
“Positive ( n =41) | Negative ( n =19) | | | MMP-9 | | | 0.0034 | | Positive ( n =25) | 18 | 7 | | | Negative ( n =35) | 17 | 18”
The paper does not include a data availability statement, nor does it deposit any data in a public repository or provide accession numbers. Custom code (if any) is not shared. This is a significant lack of transparency.
Methods are detailed but lack some elements (e.g., catalog numbers, blinding). All pre-specified outcomes appear to be reported, including negative results (no effect on E-cadherin). Conclusions are proportional to the evidence. However, no reporting checklist (e.g., ARRIVE) is referenced. The funding and conflicts of interest statement is incomplete ('The authors declare no'). Limitations are discussed implicitly but not in a dedicated section.
“no significant change was found in PANC-1 cells”
“These findings indicate that Slug may regulate the metastatic nature of PANC-1 by stimulating cell motility”
“The authors declare no”
“The authors declare no”
“Slug may serve as a marker for the prediction of the malignancy of pancreatic cancer after operation.”
“The present study for the first time has explored the relationship between Slug and MMP-9 in pancreatic cancer and clarified the novel mechanism.”
“The difference may be because of the limited number of patients or the evaluation the immunohistochemistry results.”
“The authors declare no”
Broken references and links
None found · partly checkedReferences checked against Crossref, OpenAlex and Retraction Watch for retractions and resolvability, plus declared data and code links probed for whether they resolve to content matching the paper.
Nothing surfaced — but not everything feeding this category ran (missing: data/code link verification), so read this as a partial clean bill.
Checked 39 references by DOI: 29 verified — 10 no DOI (shown, not verified).
- NO DOITranscriptional repressor Snail and progression of human hepatocellular carcinomaNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOISlug Expression in the E-cadherin preserved tumors is related to prognosis in patients with esophageal squamous cell carcinomaNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIExpression of SIP1 in oral squamous cell carcinomas: implications for E-cadherin expression and tumor progressionNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIExpression of matrix metalloproteinase-9 in pancreatic ductal carcinoma is associated with tumor metastasis formationNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIExpression of matrix metalloproteinase-9 in surgically resected intrahepatic CholangiocarcinomaNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIExpression of immunoreactive E-cadherin adhesion molecules in human cancersNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIAssociation of CC chemokine receptor 7 with lymph node metastasis of esophageal squamous cell carcinomaNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOICutaneous wound healing: a partial and reversible EMTNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIThe loss of E-cadherin, alpha- and beta-catenin expression is associated with metastasis and poor prognosis in invasive breast cancerNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
- NO DOIRelative expression of E-cadherin and type IV collagenase genes predicts disease outcome in patients with resectable pancreatic carcinomaNo DOI in the reference — shown for manual review; not independently verifiable (not a fabrication signal).
Copyediting
1 finding · worst lowWording, consistency and formatting errors that need correcting before submission.
- Wording or formatting errors that need correctingAssessed
19 copyedit issues flagged (11 major): mostly typo, clarity, consistency.
- MAJORtypoTitle and abstract“Slug enhances invasion ability of pancreatic cancer cells through upregulation of matrix metalloproteinase-9 and actin cytoskeleton remodeling Slug and invasion ability of pancreatic cancer cells”→ Slug enhances invasion ability of pancreatic cancer cells through upregulation of matrix metalloproteinase-9 and actin cytoskeleton remodelingTitle is repeated; also missing punctuation.
- MAJORtypoIntroduction“F-ascin is an actin-bundling protein involved in filopodia assembly”→ Fascin is an actin-bundling protein involved in filopodia assemblyInconsistent spelling: 'F-ascin' vs 'F-actin' later.
- MAJORgrammarEnd of manuscript“The authors declare no”→ The authors declare no conflicts of interest.Sentence is incomplete; likely missing 'conflicts of interest'.
- MAJORclarityMethods, Ethical statement“All research involving human participants was approved in written form by the patients studied and the ethics committee”→ All research involving human participants was approved by the ethics committee of the affiliated hospital of medical college, Qingdao University, and written informed consent was obtained from all patients.Ambiguous phrasing; consent and approval are conflated.
- MAJORclarityEnd of manuscript“The authors declare no”→ Complete the sentence, e.g., 'The authors declare no conflict of interest.' and add funding information.Sentence is cut off mid-phrase.
- MAJORconsistencyIntroduction, paragraph 1 and Discussion“F-ascin is an actin-bundling protein involved in filopodia assembly”→ Use 'F-actin' consistently throughout; 'F-ascin' appears to be a typo for 'F-actin'.The protein is called F-actin elsewhere in the manuscript.
- MAJORclarityFigure legends, opening fragment“mined by immunohistochemistry. Staining of Slug was found in the cytoplasm”→ Restore the missing beginning of the legend sentence, e.g., 'Expression of Slug was determined by immunohistochemistry.'The sentence starts mid-phrase, indicating dropped text.
- MAJORtypoMaterials and Methods, Cell Invasion Assays“The chamers were put into the incubator”→ The chambers were put into the incubatorMisspelling of 'chambers'.
- MAJORclarityMaterials and Methods, Patients and Tissue Samples“All research involving human participants was approved in written form by the patients studied and the ethics committee at the affiliated hospital of medical college, Qingdao University.”→ The study was approved by the ethics committee of the affiliated hospital of medical college, Qingdao University, and written informed consent was obtained from all patients.Consent and ethics approval are conflated in an awkward sentence.
- MAJORconsistencyTable 3“Table 3 Slug promoted in vivo tumor hepatic metastasis and lymph node invasion ( n =10) Groups ( n =12)”→ Use n=12 consistently, or explain the discrepancy.The caption says n=10 while the table header and text say n=12.
- MAJORotherEnd of manuscript“The authors declare no”→ The authors declare no conflicts of interest. Funding: [state funding sources].The sentence is truncated.
- MINORconsistencyMethods, Immunohistochemistry“Slug (dilution at 1:100; Santa Cruz Biotechnology) or E-cadherin (dilution at 1:100; Santa Cruz Biotechnology), or MMP-9 (dilution at 1:100, Santa Cruz Biotechnology)”→ Slug (dilution at 1:100; Santa Cruz Biotechnology), E-cadherin (dilution at 1:100; Santa Cruz Biotechnology), or MMP-9 (dilution at 1:100; Santa Cruz Biotechnology)Inconsistent use of semicolons and commas in list.
- MINORtypoMaterials and Methods, Cell Invasion Assays“The chamers were put into the incubator at 37°C”→ Change 'chamers' to 'chambers'.Spelling error.
- MINORconsistencyTable 3 header“Table 3 Slug promoted in vivo tumor hepatic metastasis and lymph node invasion ( n =10) Groups ( n =12)”→ Clarify whether n=10 or n=12; the cell counts sum to 12 per group.Header n=10 conflicts with the n=12 group sizes and cell sums.
- MINORgrammarMaterials and Methods, Patients and Tissue Samples“All research involving human participants was approved in written form by the patients studied and the ethics committee”→ Rephrase to 'All research involving human participants was approved by the ethics committee... and written informed consent was obtained from the patients.'Awkward and ambiguous phrasing of consent and approval.
- MINORtypoAbstract / Introduction“F-ascin”→ FascinThe protein name is misspelled as F-ascin.
- MINORtypoMaterials and Methods, Western Blotting“electrochemiluminescence kit (Amasham, Piscataway, NJ)”→ electrochemiluminescence kit (Amersham, Piscataway, NJ)Likely vendor name is Amersham.
- MINORgrammarMaterials and Methods, Animal Studies“Full details of the study approval by the ethics committee at the affiliated hospital of medical college, Qingdao University.”→ The study was approved by the ethics committee of the affiliated hospital of medical college, Qingdao University.This is a sentence fragment and does not clearly state that approval was obtained.
- MINORclarityFigure 1 legend“mined by immunohistochemistry.”→ determined by immunohistochemistry.Garbled phrase likely from a figure legend.
As a published work, the paper raises substantial robustness concerns. The internal inconsistency in Table 2 (cell counts not summing to stated group sizes) and the non-reproducible p-value for the Slug–MMP-9 association warrant a formal correction or independent re-analysis. The absence of data sharing, randomization, blinding, and cell line authentication further limit confidence in the reported findings. A reader should weigh these limitations heavily when interpreting the conclusions.
- 1.CRITICALstatisticsCorrect Table 2 so that the Slug-positive and Slug-negative column totals match the stated group sizes (n=41 and n=19), then recompute and report the exact p-value for the Slug–MMP-9 association using the corrected counts.The current table contains an internal inconsistency that undermines the reported p-value and invalidates the statistical conclusions drawn from that correlation.
- 2.CRITICALdata codeAdd a data availability statement and deposit the raw datasets (IHC scores, qPCR, western blot densitometry, zymography, invasion counts, metastasis counts) in a public repository (e.g., Zenodo, Figshare, GEO) with a persistent identifier.The paper provides no data sharing, which is a fundamental transparency requirement and prevents independent verification of the reported results.
- 3.CRITICALreportingTemper the claim that 'Slug may serve as a marker for the prediction of the malignancy of pancreatic cancer after operation' to a statement of association only, given the small correlative IHC series without prospective validation or multivariate adjustment.This claim is not supported by the study design (single-cohort, 60 patients, no sensitivity/specificity analysis) and overstates the clinical utility of the finding.
- 4.CRITICALreportingRemove or qualify the novelty claim 'for the first time' regarding the relationship between Slug and MMP-9 in pancreatic cancer, as the paper provides no literature-search basis to substantiate priority.Unsubstantiated priority claims are a common reviewer objection and can be perceived as misleading.
- 5.HIGHrigorReport randomization and blinding procedures for animal allocation and outcome assessment in the Animal Studies section, or justify an open design.Absence of randomization and blinding is a major source of bias in interventional animal experiments.
- 6.HIGHrigorAdd an a priori power analysis or sample-size justification for the clinical cohort, animal experiments, and cell assays in the Statistical Assessment section.Without power analysis, the sample sizes are not justified, and the risk of false-negative or false-positive findings is unclear.
- 7.HIGHotherProvide catalog numbers, clones, or RRIDs for all antibodies (Slug, E-cadherin, MMP-9) and cite validation references in the Immunohistochemistry and Western Blotting methods.Antibodies without identifiers cannot be unambiguously identified by other researchers, compromising reproducibility.
- 8.HIGHotherReport STR authentication and mycoplasma testing results for the PANC-1 cell line, or state that authenticated cells were used and mycoplasma testing was performed with negative results.Cell line misidentification and mycoplasma contamination are common sources of irreproducible results.
- 9.HIGHreportingComplete the truncated conflicts-of-interest statement and add a funding statement with grant numbers in a dedicated section at the end of the manuscript.The current statement is cut off mid-sentence, and funding information is entirely absent, which is a reporting requirement for most journals.
- 10.HIGHreportingProvide human cohort demographics (age, sex, tumor stage) and explicit inclusion/exclusion criteria in the Patients and Tissue Samples section.Demographic details are essential for assessing generalizability and potential confounding in the clinical cohort.
- 11.HIGHcopyeditCorrect the animal nomenclature inconsistency: clarify whether the mice were C57BL/6 or nude mice, and ensure consistent usage throughout the Methods and Results.The Methods refer to 'Female C57BL/6 mice' but later mention 'nude mice'; this ambiguity could affect interpretation of the xenograft model.
- 12.HIGHcopyeditCorrect the Table 3 caption: it states n=10 but the groups are labeled n=12 and cell counts sum to 12; change the caption to n=12 or explain the discrepancy.This inconsistency confuses the reader and suggests a copyediting error that may affect data interpretation.
- 13.MEDIUMstatisticsReplace all threshold p-values ('P<0.05', 'P<0.01') with exact p-values (2-3 significant figures) throughout the Results and Tables.Threshold p-values obscure the exact evidence strength and are considered poor reporting practice.
- 14.MEDIUMstatisticsReport effect sizes with 95% confidence intervals for all comparisons, and define error bars (SD or SEM) in figure legends.Effect sizes and confidence intervals provide more informative measures of association than p-values alone.
- 15.MEDIUMreportingCite an appropriate reporting guideline (ARRIVE for animal experiments, STROBE for the clinical cohort) in the Methods section.Citing reporting guidelines improves transparency and helps ensure completeness of reporting.
- 16.MEDIUMcopyeditFix the title: it is repeated in the manuscript; use 'Slug enhances invasion ability of pancreatic cancer cells through upregulation of matrix metalloproteinase-9 and actin cytoskeleton remodeling'.The current title has a duplicated phrase ('Slug and invasion ability of pancreatic cancer cells'), which is a clear copyediting error.
- 17.MEDIUMcopyeditCorrect 'F-ascin' to 'Fascin' throughout the Introduction and Discussion, and ensure consistent use of 'F-actin' where intended.The misspelling 'F-ascin' appears to be a typo for 'Fascin' or 'F-actin', and consistency is needed for clarity.
- 18.MEDIUMcopyeditRephrase the informed consent statement to clearly separate ethics approval from consent: 'The study was approved by the ethics committee... and written informed consent was obtained from all patients.'The current phrasing conflates approval and consent and is grammatically ambiguous.
- 19.MEDIUMcopyeditRestore the missing beginning of the Figure 1 legend (currently starts with 'mined by immunohistochemistry'); likely should read 'Expression of Slug was determined by immunohistochemistry.'The legend is truncated, which hinders understanding of the figure.
- 20.MEDIUMcopyeditCorrect the typo 'chamers' to 'chambers' in the Cell Invasion Assays section.Spelling errors reduce professionalism and clarity.
- 21.LOWrigorAdd detailed housing conditions for mice (light cycle, temperature, humidity, enrichment) in the Animal Studies section.Housing conditions can affect animal physiology and behavior, and their absence reduces reproducibility.
- 22.LOWrigorProvide a scientific justification for the use of only female mice, or include both sexes if feasible.Single-sex studies without justification may limit generalizability and are increasingly scrutinized by journals.
- 23.LOWotherProvide catalog numbers for all reagents (e.g., pcDNA3, Lipofectamine, G418, primers) and the specific version of the software (e.g., SPSS 13.0 for Windows).Catalog numbers and version details facilitate precise replication of the methods.
The star rating is the report’s one-glance summary. Every paper starts at 5★ and loses stars for the concrete problems the review finds — so a rating is never a vague average, it’s a running total you can read line by line under “How this rating was calculated.”
- Reporting — 8 dimensionseach dimension that fully fails−½★
- each dimension partially met−¼★
- Statistics · Integrity · Claimseach serious problem−1★
- each medium problem−½★
- Citationseach retracted or unverifiable reference−¼★
- Copyeditonly when the manuscript needs a full edit−½★
The rating never drops below 1★, and a demonstrable critical failure (an impossible statistic, a proven ethics violation) caps it at 1★ on its own — so the stars can never look healthy when the verdict is CRITICAL.
The rating draws on a panel of agents. Three independent Kaimen Rigor reviewers grade the eight dimensions below across several independent passes (the shown verdict is their majority vote — steadier than any single run), isolate the paper’s major claims and check its own evidence backs them, and flag integrity concerns. Alongside them, a citation agent resolves every reference against Crossref, OpenAlex, and Retraction Watch; a statistics agent recomputes reported tests; and rule-based checks verify that declared data/code links actually resolve. Full text is required — an abstract-only submission is not analyzed.
Graded against NIH, MDAR, ARRIVE 2.0, CONSORT, EQUATOR, and RRID guidelines. A dimension that doesn’t apply to the study type is skipped, never penalized.
This Kaimen Rigor review is model-assisted and is not a substitute for formal expert review. It complements human evaluation by surfacing potential methodological concerns — verify each finding against the source.