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Pfizer retracts articles by researcher who has left the company


A senior principal scientist for Pfizer, oncology researcher Min-Jean Yin, has departed the company and five cancer research papers in which she had a hand in crafting have since been retracted due to questionable data.

This was found by Leonid Schneider, a Germany-based science writer and he posted it on his For Better Science site on Oct. 11. Schneider has been raising questions regarding image integrity associated with six articles authored by Yin between 2010 and 2013. In a May Schneider said he was contacted by a scientist, one whose identity he did not disclose, about “image irregularities in cancer research publications” that came from Yin and Pfizer’s La Jolla research laboratories.

“The suspected irregularities this person reported on PubPeer ranged from duplicated western blots to duplicated bands inside western blots,” Schneider wrote in May on his site.

At the time, Schneider reached out to Pfizer and was told the company was looking into the concerns. This month the company finally responded.

On his site, Schneider shared an email from Yvonne Cristovici, an assistant general counsel in Pfizer’s compliance division, who confirmed the papers have been retracted due to “possible duplicate images” from publications on

“We have been able to confirm that all or nearly all of the images in these five articles that were flagged as potential duplicates on indeed appear to be duplicates. Based on the findings from the investigation, Pfizer is recommending to the journals that all five articles be retracted, and Pfizer also has encouraged the first and corresponding/senior authors of each of the five papers to request that their article be retracted,” Cristovici said in her email, according to Schneider.

Cristovici goes on to say that Yin, who was the senior author of each of the papers in question, agreed to retract the articles. She told Schneider that the company has high standards regarding data integrity.

The five papers in question Yin was the lead author of are:

• Nassirpour et. al, miR-221 Promotes Tumorigenesis in Human Triple Negative Breast Cancer Cells, 8(4) PLOS ONE, (2013);

• Baxi et. al, Targeting 3-Phosphoinoside-Dependent Kinase-1 to Inhibit Insulin-Like Growth Factor-I Induced AKT and p70 S6 Kinase Activation in Breast Cancer Cells, 7(10) PLOS ONE (2012);

• Mehta et. al, A novel class of specific Hsp90 small molecule inhibitors demonstrate in vitro and in vivo anti-tumor activity in human melanoma cells, 300 Cancer Letters 30 (2011);

• Mehta et. al, Effective Targeting of Triple-Negative Breast Cancer Cells by PF-4942847, a Novel Oral Inhibitor of Hsp 90, 17(6) Clinical Cancer Research 5432, 2011; and

• Nassirpour et. al, Nek6 Mediates Human Cancer Cell Transformation And Is A Potential Cancer Therapeutic Target, 8(5) Molecular Cancer Research 717 (2010).

According to her LinkedIn profile, Yin now works as a general manager for San Diego-based Diagnologix, LLC, a startup focusing on developing diagnostic tools and products for unmet medical needs. In his report, Schneider writes that he believes the retracted papers and questionable data led to Pfizer terminating Yin’s position.

The website Retraction Watch noted that some of the images have been corrected in the publications they appeared, including “Clinical Cancer Research” and “Molecular Cancer Research.”