The decision follows a detailed examination of several figures in the original paper, which had been published online on 8 August 2017. According to the retraction notice, concerns were raised about overlapping sections within and between multiple figure panels. In Figure 2A, a section of the Control/DAPI panel appeared to overlap with other material, and in Figure 3A a section of the WHO Grade I/DAPI panel showed similar duplication. DAPI is a fluorescent stain used to label cell nuclei, so panels built around it are typically used to document the distribution and appearance of cells in tumour tissue samples. Overlapping sections in such panels suggest that the same imaging data may have been reused to represent different experimental conditions.

The problems were not confined to those two figures. The journal identified overlapping sections across multiple panels within Figure 4A and within Figure 7D, as well as overlaps between panels of Figure 4A and Figure 7D. In a further instance, the lower-left section of the Migration/U251/Mock panel of Figure 7A appeared to overlap with the upper-right section of the Migration/U251/Scr panel of Figure 7D. Migration assays using the U251 glioma cell line, comparing mock-transfected controls with cells treated with a scrambled control sequence, are central to claims about tumour cell motility, so duplication in these panels strikes at the heart of the paper’s invasion-suppressor hypothesis.

Yet another concern involved western blot data, a technique used to detect specific proteins in a sample by separating them on a gel and probing them with antibodies. The retraction notice states that the U251/p-Cofilin bands of Figures 8B and 8C appear to overlap. Cofilin is a protein involved in actin remodelling and cell movement, and its phosphorylation status was part of the mechanistic story linking the miR-29 family to CDC42 and the invasive behaviour of glioma cells. Overlapping bands in western blots raise the possibility that the same experimental result was presented more than once, potentially as evidence for different comparisons.

When the concerns emerged, the authors were asked to substantiate their findings. According to the retraction notice, the authors provided some original data upon request, but this material could not be verified. That inability to verify the underlying records left the Editor-in-Chief with little alternative but to withdraw the paper. Shizhu Yu and Qian Wang, the corresponding authors, stated on behalf of all authors that they agree to the retraction. The notice does not describe any finding of misconduct against specific individuals; it records only that confidence in the reliability of the reported data has been lost.

The original study had attracted attention because it tied together several threads of glioma biology into a single narrative. MicroRNAs are short RNA molecules that do not code for proteins but instead regulate gene expression after transcription, typically by binding to messenger RNAs and suppressing their translation or promoting their degradation. The miR-29 family, comprising miR-29a, miR-29b and miR-29c, had previously been implicated in a range of cancers, and the 2017 paper argued that these molecules suppress the invasive behaviour of glioma cells by targeting CDC42, a member of the Rho family of GTPases that controls cytoskeletal organisation, cell polarity and migration. The paper also claimed that the expression levels of these microRNAs could predict the prognosis of patients with gliomas, offering a potential biomarker for a disease in which reliable prognostic indicators are urgently needed.

Gliomas are the most common primary brain tumours in adults, and the most aggressive form, glioblastoma, remains one of the deadliest human cancers despite decades of research. A key reason for its lethality is the diffuse way tumour cells infiltrate surrounding healthy brain tissue, which makes complete surgical resection nearly impossible and leaves behind cells that drive recurrence. Understanding the molecular machinery that governs invasion, including CDC42 and the actin-regulating proteins downstream of it such as cofilin, has therefore been a major research priority. That context explains why the original paper’s claims were consequential and why their retraction matters to researchers who may have built on the findings.

The retraction also illustrates how the scientific literature polices itself through image integrity analysis. Modern forensic tools make it possible to detect duplicated regions within and between published figures, even when the copies have been flipped, rotated or subtly adjusted. Overlaps between a DAPI-stained tissue panel in one figure and a migration assay panel in another are particularly difficult to explain innocently, because they suggest shared source images across experiments that should have generated independent data. Journals including those published by Springer Nature routinely act on such findings, requesting original data from authors and retracting papers when verification fails.

For the field, the immediate consequence is that the specific claims linking miR-29a/b/c to CDC42-mediated invasion suppression and prognostic prediction in glioma patients can no longer be relied upon as published evidence. Researchers citing the work will need to note its retracted status, and meta-analyses or reviews that incorporated its data will require revision. The retraction notice records 548 accesses to the notice itself, a reminder that withdrawn papers continue to be consulted long after publication. Whether the underlying biology of the miR-29 family in gliomas is accurate remains an open question; the retraction speaks to the integrity of the reported data rather than disproving the hypothesis outright, and independent laboratories would need to establish any such role through verifiable experiments.

The episode adds to a growing record of retractions in cancer biology, where high-volume imaging and blot-based experiments create many opportunities for error or manipulation, and where automated screening has dramatically increased detection. The British Journal of Cancer, which published the original article and the retraction, has made the notice freely available alongside the original paper’s record, with the canonical retraction notice carrying its own DOI, 10.1038/s41416-026-03643-3, distinct from the original article’s DOI of 10.1038/bjc.2017.255. For now, the 2017 study stands as a cautionary example: a biologically plausible and appealing story about microRNAs taming brain tumour invasion, undone by figures that could not withstand scrutiny and original data that could not be verified.

Subject of Research: Retraction of a 2017 glioma study on miR-29a/b/c microRNAs targeting CDC42 due to figure image duplication

Article Title: Retraction Note: miR-29a/b/c function as invasion suppressors for gliomas by targeting CDC42 and predict the prognosis of patients

Article References: Shi, C., Ren, L., Sun, C., Yu, L., Bian, X., Zhou, X., Wen, Y., Hua, D., Zhao, S., Luo, W., Wang, R., Rao, C., Wang, Q., & Yu, S. (2026). Retraction Note: miR-29a/b/c function as invasion suppressors for gliomas by targeting CDC42 and predict the prognosis of patients. British Journal of Cancer. https://doi.org/10.1038/s41416-026-03643-3

Image Credits: AI Generated

DOI: 10.1038/s41416-026-03643-3

Keywords: glioma, microRNA, miR-29, CDC42, retraction, British Journal of Cancer, research integrity, image duplication, western blot, tumour invasion, prognosis, U251

The motivation behind miRDrug stems from a well-known problem in pharmaceutical research: identifying new therapeutic targets is extraordinarily expensive, and wet-lab experiments to uncover microRNA-drug relationships are slow, complex and resource-intensive. Computational approaches offer a cost-effective alternative, but most existing tools examine only a single slice of the picture, such as microRNA-disease or gene-pathway associations. The authors argue that this fragmentation impedes a comprehensive understanding of how microRNA expression shapes drug response. Their solution is to integrate prior biological knowledge directly into the machine-learning pipeline, so that the algorithm does not just crunch numbers but reasons over curated biological facts.

At the heart of miRDrug is the Grouping-Scoring-Modeling approach, or G-S-M, a framework previously developed by Yousef and colleagues and already deployed in tools such as GediNET, miRGediNET, maTE and PriPath. The strategy is elegant in its simplicity. First, features, in this case genes, are grouped according to external biological knowledge rather than left as thousands of individual columns of expression data. Second, each group is scored for how well it discriminates between two classes of samples, such as patients and healthy controls. Third, the top-ranked groups are fed into a machine-learning classifier, here a Random Forest, to build a predictive model. What sets miRDrug apart is a new component the authors call 3BPK, for Three Biological Prior Knowledge, which fuses information from miRTarBase version 9.0, the ncRNADrug database version 1.0 and the Drug-Gene Interaction Database DGIdb version 5.0.

The 3BPK module works by pairing microRNAs with drugs using the ncRNADrug database, then retrieving the target genes of each microRNA from miRTarBase and the associated genes of each drug from DGIdb. For every microRNA-drug pair, the tool computes the intersection of the two gene sets, producing a group of genes that are simultaneously linked to the microRNA and the drug. In total, the integrated databases supply 2,599 microRNAs connected to 15,064 genes through 502,652 interactions, 23,268 drugs linked to 3,899 genes through 81,129 interactions, and 17,372 microRNA-drug relationships covering 2,550 microRNAs and 326 drugs. From these resources, the researchers constructed 14,725 unique microRNA-drug pairs, each with its own shared-gene group and a Jaccard-style similarity score quantifying the overlap between the two gene sets.

The resulting overlap statistics reveal how sparse, yet meaningful, these connections can be. Some pairs, such as the microRNA hsa-let-7a-2-3p with the chemotherapy drug oxaliplatin, share no genes at all, yielding a similarity score of zero. Others show richer intersections: hsa-let-7a-5p paired with doxorubicin shares seven genes including bcl2, ccnd1 and casp3, while hsa-mir-26b-5p paired with cisplatin shares 27 genes, among them well-known cancer genes such as brca1, rb1 and myc. A histogram of the distribution shows a strongly right-skewed pattern, with 5,021 of the pairs having no common genes and progressively fewer pairs sharing larger numbers. The authors emphasize that an overlap does not imply direct molecular interaction; rather, it suggests shared pathways or biological relevance that could guide future experiments.

To test whether these biologically defined gene groups carry real predictive signal, the team applied miRDrug to ten human gene expression datasets from the Gene Expression Omnibus, spanning diseases from glioma and prostate cancer to lung adenocarcinoma, leukemia, pulmonary hypertension, colorectal cancer and colitis. Each dataset was evaluated with 100 repeated stratified train-test splits, using 90 percent of samples for training and 10 percent for held-out testing, with an inner five-fold cross-validation used to score candidate groups. The results were striking in several cases. On the GDS4516_4718 colorectal cancer dataset, miRDrug achieved an area under the curve of 0.999 with an accuracy of 0.994 using only about 5.6 genes from its top two ranked groups. The glioma dataset GDS1962 reached an AUC of 0.944, and the lung adenocarcinoma dataset GDS3257 hit 0.979. Performance was weaker on the pediatric acute lymphoblastic leukemia relapse dataset GDS4206, which the authors attribute to the high biological heterogeneity of relapsed cancers and the limits of a two-class classification framework.

Importantly, the tool does more than classify. Using the RobustRankAggreg method with Benjamini-Hochberg false discovery rate correction, miRDrug prioritizes which microRNA-drug groups and which individual genes are most statistically reliable in a given disease context. In the prostate cancer dataset GDS2545, the top-ranked groups included hsa-miR-26b-5p paired with docetaxel and paclitaxel, carrying genes such as PTEN, FGFR3, GSTP1 and ABCG2, all plausibly tied to drug response and tumor biology. In the lung cancer dataset GDS3837, prioritized genes included NT5E, EGFR, ERBB2, ABCC3 and BDNF, each associated with cancer signaling or drug response. A comparison against a conventional Random Forest trained on all 12,558 retained features of the prostate dataset showed that the all-feature baseline achieved a slightly higher AUC of 0.849 versus 0.818, but miRDrug matched its accuracy of roughly 0.76 while using only about 16 genes, and, crucially, produced interpretable biological outputs that the black-box baseline cannot offer.

The most compelling case study came from breast cancer. Applying miRDrug to The Cancer Genome Atlas breast invasive carcinoma cohort, the researchers classified the Luminal A/B molecular subtypes against the HER2-enriched and basal-like subtypes, achieving a remarkable AUC of 0.99 with just 7.5 genes in the top-ranked group. That top group was the pairing of hsa-miR-29b-3p with tamoxifen, the widely used selective estrogen receptor modulator, sharing the genes ESR1, TGFB1, CCNA2 and NCOA3. The biological logic is coherent: ESR1 encodes the estrogen receptor alpha that drives many breast cancers, TGFB1 regulates proliferation and epithelial-to-mesenchymal transition, CCNA2 controls the cell cycle, and NCOA3 is a transcriptional coactivator implicated in tumor progression. Prior literature links the miR-29 family to tumor suppression and to tamoxifen sensitivity, and studies suggest that modulating miR-29b-3p levels could restore hormone-therapy responsiveness in resistant cells. Other top-ranked microRNAs in the breast cancer analysis, including miR-193b-3p, miR-302b-3p and miR-222-3p, likewise align with known roles in tumor suppression or progression.

The authors are candid about the limitations. The system depends on curated databases that may be incomplete or biased toward well-studied genes, meaning novel interactions could be missed. The pipeline is sensitive to noise in heterogeneous clinical data, and the scoring and ranking stages introduce computational overhead as dataset size grows. Most importantly, the findings remain computational prioritizations rather than experimentally validated mechanisms; the team plans in vitro studies to test high-confidence predictions. Even so, miRDrug represents a meaningful step toward integrative, knowledge-guided bioinformatics. By fusing three complementary databases into a single grouping-scoring-modeling pipeline, it offers researchers a systematic way to generate hypotheses about microRNA-drug-gene triads, particularly in the context of drug resistance, and moves the field closer to the personalized-medicine goal of tailoring therapies to the regulatory genetics of each patient’s tumor. The workflow is publicly available on GitHub, allowing other groups to reproduce the analyses and extend the approach to new datasets and disease contexts.

Subject of Research: A computational tool integrating microRNA, drug and gene interaction databases to study drug resistance mechanisms

Article Title: miRDrug: Comprehensive analysis of the shared genes within miRNA-drug pairs using grouping, scoring, and modeling approach

Article References: Qumsiyeh, E., Bakir-Gungor, B., & Yousef, M. (2026). miRDrug: Comprehensive analysis of the shared genes within miRNA-drug pairs using grouping, scoring, and modeling approach. Heliyon, 12(15), Article e45548. https://doi.org/10.1016/j.heliyon.2026.e45548

Image Credits: AI Generated

DOI: 10.1016/j.heliyon.2026.e45548

Keywords: microRNA, drug resistance, machine learning, bioinformatics, cancer, gene expression, tamoxifen, miR-29, Random Forest, database integration, personalized medicine, G-S-M approach