WARNReviewer 1· 85% conf
The study design has several strengths (replicates, controls) but lacks key rigor elements such as randomization, blinding, power analysis, and outlier handling.
Evidence
direct quote[Methods, Cell Invasion Assays]
“Individual experiments were done in duplicate and repeated four times.”paraphrase[Methods, BB94 Treatment and Cell Culture]
“PANC-1 cells were transfected with pcDNA3-Slug cDNA or control pcDNA3 vector; BB94 was used as a specific MMPs inhibitor.”absence[Methods, all sections]
No randomization, blinding, power analysis, or outlier handling is reported.WARNReviewer 2· 65% conf
Controls and patient inclusion criteria are adequately described, but randomization, blinding, power analysis, outlier handling, and independent replication are absent, with biological vs. technical replicates not clearly distinguished.
Evidence
direct quote[Materials and Methods, Cell Culture/BB94 and Results]
“Slug-transfected or mock-transfected or untreated PANC-1 cells were plated at a density of 5 × 10 4 /mm 2 in culture dishes”direct quote[Materials and Methods, Patients and Tissue Samples]
“Between 1999 and 2009, 60 consecutive pancreatic adenocarcinoma (ordinary ductal carcinoma) specimens for which tissue was available for immunohistochemical staining were identified”direct quote[Materials and Methods, Cell Invasion Assays]
“Individual experiments were done in duplicate and repeated four times.”FAILReviewer 3· 75% conf
The study uses a descriptive clinical cohort plus cell-line and mouse experiments, but randomization, blinding, a priori power analysis, pre-specified inclusion/exclusion criteria, and independent replication are absent; only controls are adequately described.
Evidence
paraphrase[Materials and Methods, Patients and Tissue Samples]
“Between 1999 and 2009, 60 consecutive pancreatic adenocarcinoma (ordinary ductal adenocarcinoma) specimens for which tissue was available for immunohistochemical staining were identified from the files of General Surgery, the affiliated hospital of medical college, Qingdao University.”direct quote[Materials and Methods, Cell Invasion Assays]
“Individual experiments were done in duplicate and repeated four times.”direct quote[Materials and Methods, Cell Culture and Stable Transfection of PANC-1 Cells]
“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).”