s**u
发帖数: 9035 | 1 Dr. Samuel M Cohen(Chairman of Department of Pathology, UNMC) wrote a letter to "Toxicological Science" to criticize a misleading from Chengfeng Yang(Michigan State University)lab's a recent paper published in this journal, see below:
Reply to “Reversal and Prevention of Arsenic-Induced Human Bronchial
Epithelial Cell Malignant Transformation by MicroRNA-200b”
1. Samuel M. Cohen1
+ Author Affiliations
1. Department of Pathology and Microbiology, University of Nebraska
Medical Center, Omaha, NE 68198-3135
1. ↵1For correspondence via Fax: (402) 559-8330. E-mail: scohen@
unmc.edu
Received May 9, 2011.
Accepted May 10, 2011.
In reviewing the article by Wang et al. entitled, “Reversal and Prevention
of Arsenic-Induced Human Bronchial Epithelial Cell Malignant Transformation
by MicroRNA-200b,” I became concerned regarding the pathology of the “
tumors” that grew in the nude mice upon transplantation of bronchial
epithelial cells “transformed” by arsenite in vitro. The documentation of
the pathology consists of a single, small photograph which is difficult to
interpret with regard to the histopathology. Based on appearance, however, I
am concerned that these tumors do not represent bronchial epithelial
malignancies, but rather, either represent inflammatory tissue or
mesenchymal proliferation, either benign or malignant. Whether inflammation
or mesenchymal proliferation, neither would be indicative of an effect that
is representative of the kinds of tumors that occur in humans in response to
arsenic. The authors indicate that there is epithelial to mesenchymal
transformation in vitro, and they take this as a sign of malignant
transformation. However, in reality, that is a late effect in malignant
progression and usually is associated with metastatic growth for lung tumors
. The tumors in humans that are induced by arsenic are all carcinomas. Lung
carcinomas in humans rarely have sarcomatoid (mesenchymal) differentiation,
which represent a rare subtype, and even in those tumors epithelial
differentiation is evident. More substantial evidence should be provided by
the authors that these truly represent epithelial-derived tumors, either
additional histopathology or more definitively by a pankeratin
immunohistochemical stain. Without such documentation, the interpretation of
this article is misleading. If these are not carcinomas, the publication
would be more accurate to indicate that they have produced epithelial to
mesenchymal transformation but that this does not necessarily imply
carcinoma transformation in vitro by arsenite. For comparison, in vitro
transformation of urothelial cells by trivalent arsenicals produced
carcinomas when transplanted into nude mice (Somji et al., 2006; Wnek et al.
, 2010).
A more limited issue that also needs to be addressed is that this
transformation in vitro is only occurring in p53-deficient cells. This is
similar to other in vitro models with arsenic, such as those involving
urothelial UROTsa cells that have been reported by others (Somji et al.,
2006; Wnek et al., 2010). In contrast, individuals who develop tumors in
response to arsenic exposure are usually not p53 deficient nor are many of
the tumors that are induced. | s**u
发帖数: 9035 | 2 There are too much misleading in toxicological studies, especially how to
interprete results of animal studies. This is the reason why Dr. Cohen (
Chairman of Department of Pathology, UNMC) wrote this letter to this journal
to expose this misleading.
Chengfeng Yang's profile as below
http://www.psl.msu.edu/yang.html |
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