Bharat Aggarwal, the highly cited MD Anderson Cancer Center researcher who has confirmed to us that his work is under investigation by the institution, has a correction of his work in the Journal of Molecular Medicine. Troubled images are to blame — as they have been in previous retractions, and at least one other correction, of Aggarwal’s papers.
The paper, “Celastrol suppresses invasion of colon and pancreatic cancer cells through the downregulation of expression of CXCR4 chemokine receptor,” was published in December 2010 and cited 15 times since, according to Thomson Scientific’s Web of Knowledge.
Here’s the notice:
The authors claim that Figs. 5a and b, and 6a and d, reporting data from in vitro invasion assays were published incorrectly. Specifically, two images of invaded cells were by mistake duplicated. The authors performed 2 additional experiments to confirm their data. The results from these experiments are reported in the corrected versions of the figures and legends, as well as the corresponding results section that are shown below. The authors claim that this correction does not influence the conclusion of the study and would like to apologize for this oversight.
Fig. 5
Celastrol suppresses invasion in colon cancer cells. a HCT116 cells (0.25 × 106 cells per well) were transfected with siRNAs and the transfected cells were collected after 48 h. After transfection, cells were seeded in the top chamber of Matrigel. Transwell chambers were then placed into 24-well plates in which either the basal medium was added or 100 ng/mL CXCL12 in the basal medium. After the incubation, invasion assay was done as described in the “Materials and methods” section. The results shown are representative of two independent experiments. b Histogram of data obtained from invasion assay in Fig. 5a. …, bars SE. *P < 0.05
Fig. 6
Celastrol suppresses CXCR4 and invasion in pancreatic cancer cells. a Left panel AsPC-1 cells (2 × 105; 2 % FBS–DMEM) were seeded in the top chamber of Matrigel. After preincubation with or without celastrol (3 μmol/ L) for 6 h, Transwell chambers were then placed into 24-well plates in which either the basal medium was added or 100 ng/mL CXCL12 in basal medium. After incubation, invasion assay was done as described in the “Materials and methods” section. The results shown are representative of two independent experiments. Right panel histogram of data obtained from invasion assay in Fig. 6a, left panel, SE. *P < 0.05. …d Left panel MIA PaCa-2 cells (2 × 105; 2 % FBS–DMEM) were seeded in the top chamber of Matrigel and invasion assay was done as describe above. The results shown are representative of two independent experiments. Right panel histogram of data obtained from invasion assay in Fig. 6d, left panel
That’s followed by the heading “Results,” under which appears this paragraph:
CXCR4 is essential for CXCL12-induced invasion
Disruption of CXCR4 and CXCL12 interaction by selective antagonists or anti-CXCR4 antibody blocks cancer metastasis, suggesting an essential role for CXCR4. Therefore, when HCT116 cells were transfected with siRNA specific for CXCR4, it efficiently inhibited CXCL12-mediated invasion to about 31 % compared to the control condition. (Fig. 5a, b). Indeed, the CXCR4-specific siRNA reduced CXCR4 protein expression (Fig. 5c).
Maybe I’m being picky. However, I think that if you repeat the invasion data for the siRNA knockdowns (Figures 5a and b) then you need to confirm that the siRNA worked when generating the new data. THerefore, you need Figure 5c to be replaced by the data from THIS experiment. (You can’t use the old control for a new experiment. THis is why you must have a different actin blot for each blot – it controls for each experiment.)
May I ask a question – why do all erratums never, ever alter the data analysis or conclusions? This work was done at one of the most prestigious cancer centres in the World and anyone who has read SF will be flabbergasted!
Great reporting guys!
It’s in the nature of an erratum that the conclusions are not altered. If the conclusions are altered (substantially) when the correction is made, the original paper is generally retracted. In corrections you sometimes see some minor changes of the conclusion, but not major. Again, in those cases the paper is retracted.
good response…
Interesting! I can undertsand a typo or a mislabel of a figure being an erratum – they are genuine errors that do occur. But, with the huge effort put into review, that is increasingly unlikely.
But, what if the erratum concerns a blot with multiple splices, with lack of controls? Or an image used in one paper being manipulated, such as a reduced FACS trace or a reduced intensity or flipped cel/tissuel image, being used in another paper?
Or perhaps several blots, spliced over several papers?
Should the scientific community use a different term for the image manipulation erratums?
good point!
For those who are interested in 11jigens expert work on alleged science misgivings in cancer research.
http://md-anderson-cc.blogspot.co.uk/
This really is mindblowing stuff!
In reply to Stewart January 24, 2013 at 2:19 pm
11jigens is an amazing expert.
Another BB Aggarwal paper where the figures a just a bit below standard.
J Biol Chem. 2004 Apr 23;279(17):17515-23.
http://www.jbc.org/content/early/2004/02/06/jbc.M313816200