A 2017 study that appeared to reveal how a tiny regulatory RNA molecule controls the growth of gastric cancer cells has been formally retracted, closing the book on a paper that once attracted attention from researchers probing the molecular machinery of one of the world’s deadliest cancers. The retraction note, published in the Journal of Experimental & Clinical Cancer Research, states that the Editor-in-Chief has lost confidence in the data after two independent and fundamental technical failures came to light: a flawed normalization procedure in the microRNA experiments and the use of gastric cancer cell lines that turned out to be contaminated with HeLa cervical cancer cells. Together, these problems strike at the very foundations of the study’s central claim that the microRNA miR-511 regulates the protein TRIM24 to modulate cell proliferation in gastric cancer.
The original article, published on 23 January 2017 by a team at the Department of Oncology of the First Affiliated Hospital of Nanchang University in China, reported that miR-511, a short non-coding RNA, could influence the behavior of gastric cancer cells by targeting TRIM24, a protein belonging to the tripartite motif family of E3 ubiquitin ligases. The paper was part of a broader wave of research into microRNAs, the roughly 20 to 24 nucleotide RNA fragments that fine-tune gene expression after transcription and have been implicated in nearly every aspect of tumor biology, from proliferation and invasion to resistance against chemotherapy. For a cancer as difficult to treat as gastric cancer, which remains among the leading causes of cancer death worldwide, any molecular handle on cell proliferation seemed worth pursuing.
The first problem identified by the retraction note concerns how the microRNA measurements were normalized, a step that is deceptively simple but absolutely critical to the validity of quantitative PCR experiments. When scientists measure the abundance of a microRNA, they do so relative to a reference molecule whose levels are assumed to remain stable across all samples and conditions. The original paper stated that microRNA results were normalized to U6 snRNA, a small nuclear RNA that has long served as a conventional, if sometimes controversial, reference in microRNA studies. The trouble, according to the retraction, is that the primers actually used in the experiments did not amplify U6 at all. Instead, they amplified the messenger RNA of LSM5, a protein-coding gene involved in RNA splicing.
That distinction matters far more than it might first appear. U6 snRNA is a small, abundant, non-coding RNA whose expression is generally treated as constitutive, which is precisely why it became a default reference in the microRNA field. LSM5, by contrast, is a messenger RNA encoding the Sm-like protein 5, a component of the spliceosomal machinery, and there is no reason to expect its levels to remain constant across cancer cell lines, treatments, or experimental manipulations. If LSM5 expression happened to shift between the compared groups, every downstream calculation of relative microRNA abundance would be skewed, potentially producing apparent differences in miR-511 levels that were nothing more than artifacts of a moving baseline. The retraction note states plainly that the normalization procedure described is incorrect and that the conclusions based on these data cannot be considered reliable.
Primer specificity errors of this kind are more common than many researchers would like to admit. In quantitative reverse transcription PCR, the design of primers determines which molecule in a complex cellular extract gets amplified and measured. A primer set intended for one RNA species can, if misdesigned, misordered, or mislabeled, silently target another. When the mistake goes undetected, the resulting fold-change values can look perfectly plausible, pass peer review, and enter the literature as apparently solid findings. It is often only years later, when readers scrutinize the methods, request the primer sequences, or attempt to replicate the results, that the discrepancy surfaces. In this case, the retraction indicates that concerns were raised after publication, prompting the editorial investigation that ultimately led to the withdrawal.
The second pillar of the retraction is arguably even more consequential for the wider cancer research community. The retraction note reports that the BGC823, MGC803, and SGC7901 cell lines used in the study have been reported to be contaminated with HeLa cervical cancer cells, rendering them unsuitable as models of gastric cancer. HeLa, the immortal cell line derived from Henrietta Lacks in 1951, is the most notorious cross-contaminant in laboratory biology. Its aggressive growth and remarkable robustness have allowed it to overtake and displace the original cells in countless cultures around the world, often without the researchers knowing. An experiment performed on what is labeled as a gastric cancer line but is actually dominated by HeLa cells is, in effect, an experiment on cervical cancer cells wearing a false label.
Cell line misidentification and cross-contamination have plagued biomedical research for decades, and estimates of the fraction of published studies using problematic lines run disturbingly high. Authentication of cell lines through short tandem repeat profiling, a technique that fingerprints the genetic identity of a culture, is now demanded by many journals and funding agencies precisely because of cases like this one. The three lines implicated in the retracted paper have appeared in hundreds of publications over the years, and their compromised status has been documented in registries of misidentified cell lines. Yet they continue to circulate in laboratories, often passed along between groups with the assumption that a vial labeled BGC823 or SGC7901 contains what the label says. The retraction serves as a fresh reminder that a cell line’s provenance must be verified, not presumed.
The combination of the two failures is what makes the retraction unavoidable from a scientific standpoint. Even if the microRNA measurements had been correctly normalized, the biological conclusions would still rest on cells that were not what the authors believed them to be. Conversely, even authentic gastric cancer cells could not have rescued a dataset whose reference gene was misidentified. The Editor-in-Chief concluded that confidence in the data could not be maintained, and the article was retracted accordingly. The retraction note also records the human dimension of the process: authors Ziling Fang, Jianping Xiong, and Xiaojun Xiang agreed with the retraction, while the remaining authors did not respond to correspondence regarding it. Such partial responses are common in retraction cases and often reflect the difficulty of reaching co-authors years after the original work was completed.
For the field of gastric cancer biology, the retraction removes one data point from a crowded literature on microRNA regulation of TRIM24, but it does not necessarily invalidate the broader hypothesis that miR-511 or related microRNAs influence TRIM24 expression in gastrointestinal tumors. TRIM24 has been independently implicated in multiple cancers as an oncogenic regulator that links chromatin remodeling with hormone signaling and degradation of tumor suppressors, and microRNA control of TRIM24 has been reported by other groups using different models and methods. The distinction that matters is between a hypothesis, which may well survive, and a specific dataset, which can no longer be trusted or cited as evidence. Researchers building on the 2017 paper will now need to look to studies performed with authenticated cell lines and verifiable normalization schemes.
The episode also illustrates how the machinery of research integrity works in practice. Concerns raised after publication are evaluated by journal editors, sometimes with input from institutional investigators, and when the evidence shows that the foundations of a paper are unsound, retraction follows regardless of the authors’ intentions. Errors of this kind, a mislabeled primer and contaminated cultures, may be honest mistakes rather than deliberate misconduct, but the scientific record cannot distinguish between them when the data themselves are unreliable. Retraction is the mechanism by which the literature corrects itself, ensuring that clinicians and researchers who search for evidence on miR-511 and TRIM24 are not misled by findings that cannot stand. For laboratories still working with BGC823, MGC803, or SGC7901, the message is unambiguous: authenticate your cells, verify your primers, and treat every reference gene as a hypothesis to be tested rather than a convention to be trusted.
Subject of Research: Retraction of a gastric cancer study on miR-511 regulation of TRIM24 due to qPCR normalization errors and HeLa-contaminated cell lines
Article Title: Retraction Note: Regulation of TRIM24 by miR-511 modulates cell proliferation in gastric cancer
Article References: Zhang, L., Liao, Q., Wang, Y., Yu, F., Feng, M., Xiang, X., & Xiong, J. (2026). Retraction Note: Regulation of TRIM24 by miR-511 modulates cell proliferation in gastric cancer. Journal of Experimental & Clinical Cancer Research, 45(1), Article 206. https://doi.org/10.1186/s13046-026-03838-9
Image Credits: AI Generated
DOI: 10.1186/s13046-026-03838-9
Keywords: gastric cancer, retraction, miR-511, TRIM24, microRNA, U6 snRNA, LSM5, HeLa contamination, cell line misidentification, qPCR normalization, BGC823, research integrity
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Nathaniel Bowman. (October 1, 2026). Gastric Cancer Study Retracted After Primer Mix-Up and HeLa Contamination Surface. Scienmag. https://scienmag.com/gastric-cancer-study-retracted-after-primer-mix-up-and-hela-contamination-surface/
Nathaniel Bowman. “Gastric Cancer Study Retracted After Primer Mix-Up and HeLa Contamination Surface.” Scienmag, 1 October 2026, https://scienmag.com/gastric-cancer-study-retracted-after-primer-mix-up-and-hela-contamination-surface/. Accessed 1 October 2026.
Nathaniel Bowman. “Gastric Cancer Study Retracted After Primer Mix-Up and HeLa Contamination Surface.” Scienmag. October 1, 2026. https://scienmag.com/gastric-cancer-study-retracted-after-primer-mix-up-and-hela-contamination-surface/
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Tags: BGC823cell line contamination issuescell line misidentificationexperimental validation in cancer studiesgastric cancergastric cancer researchHeLa cell contamination in experimentsHeLa contaminationimpact of cell line contamination on research validityimportance of proper cell line authenticationLSM5microRNAmicroRNA miR-511 in cancermicroRNA regulation in cancermiR-511molecular mechanisms of gastric cancernormalization procedures in microRNA studiesqPCR normalizationresearch integrityresearch retraction due to technical errorsretractionTRIM24TRIM24 protein role in tumor growthU6 snRNA
