Long noncoding RNA BCAR4 promotes glioma cell proliferation via EGFR/PI3K/AKT signaling pathway
Authors: Kongyan Guo
Lian Wei
Xu Long
Zhao Yi
Journal: Journal of Cellular Physiology (2019)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: BCAR4; EGFR; PI3K/AKT pathway; glioma; proliferation.
Affiliations: Department of Neurosurgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China., Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Abstract:  Long noncoding RNA Breast Cancer Antiestrogen Resistance 4 (BCAR4) has been identified to be oncogenic in several cancers. In our study, we demonstrated that BCAR4 expression was significantly upregulated in glioma tissues compared with paired nontumor tissues. In addition, higher BCAR4 level was associated with poor overall survival in patients with glioma. Besides, we also discovered that knockdown of BCAR4 inhibited cell proliferation, whereas BCAR4 overexpression promoted this process. Intriguingly, we proved a cellular transformation of normal human astrocyte cells (NHAs) in response to enforced expression of BCAR4. In addition, we revealed that BCAR4 affected cell proliferation in glioma cells by promoting cell cycle progression and inhibiting cell apoptosis. Mechanistically, we uncovered that BCAR4 activated PI3K/AKT signaling pathway in glioma through upregulating EGFR and interacting with it. Moreover, activating PI3K/AKT pathway could reverse the repressive effects caused by BCAR4 silence on the biological behaviors of glioma cells, whereas inhibition of this pathway rescued the impact of BACR4 upregulation in NHAs. These findings disclosed that BCAR4 contributes to glioma progression by enhancing cell growth via activating EGFR/PI3K/AKT pathway, providing potent evidence that BCAR4 could be an effective new target for treatment and prognosis of glioma patients. 

Retracted: Yes

PubPeer comments:
 I noticed differences between the distribution of data in this article compared to other articles by this author measuring the same thing. In particular, the distribution of activity level values among individuals seems quite different in this study compared to others despite the studies purporting to use identical methodology. Specifically, the variance is much lower. I will outline my findings in this post and then post several specific questions at the end. There may be a very obvious reason why these differences were observed, and I would be grateful if the author could please clarify. I am making no allegations in this post whatsoever, in fact I can think of several biological reasons why this would be the case (eg selection on variance). Rather I am seeking for clarification on why such differences might exist and evidence from the author that the differences in variance noted here also appear in other datasets that would have captured this (which have not been made public). In addition, my findings might prove useful in light of other posts I have made on PubPeer. The goal of the present study was to document how dragonfly nymphs change their activity levels in response to the presence of a predator and then to document the larger ecosystem level consequences of this behavioural plasticity. The author measured activity level (cumulative movement of a nymph over 3 hours measured at 20 minute time intervals) of different individuals within a species in the presence of a predator vs. absence. The results of this are very clean. Here is a figure of the raw data with some jitter added horizontally. Blue points are measured in the presence of a predator, red in the absence: ![file] What I noticed was that the variation in activity level for *Epitheca canis* ( E_s in the raw data) was much lower in this study than in other studies that measured the same variable in this species. I wanted to compare the data for individual activity from this study, downloaded from Dryad (http: dx.doi.org 10.5061 dryad.4tmpg4f6f) to other datasets by this author measuring individual variation in activity rate for *Epitheca canis*. Those two additional studies are:  Animal behaviour and algal camouflage jointly structure predation and selection (Journal of Evolutionary Biology; data on Dryad), and  Ontogeny and Consistent Individual Differences Mediate Trophic Interactions (Am Nat; the data were extracted manually from Fig 1A). Plotting the equivalent data across studies, at least I understand it as being equivalent, yields the following graph: ![file] Unless I missed it, the author does not state when the study animals were collected and also does not give the location of the specific ponds. This could be caused by differences in populations. In the *Am Nat* study, the author notes that the mean differs quite a bit among populations, writing: ![file] I evaluated whether the means of these populations differed in the data plotted above, and they do not. Here is a screenshot of the R code and model result. ![file] This shows that the main effect of environment (ie predator presence absence) is significant (as expected) but the mean activity does not differ among studies. It remains possible that the assays were done on individuals from different populations and different years. I wanted to determine the probability of observing a variance as low as what was observed here if we assume the previous data was a random sample. To do this I used bootstrapping, focussing on the individual from the no predator treatment (to avoid confounding variation introduced by individual predators) and using the no predator data from the 2018 am nat paper as the sample. The variance observed in the present article for *Epitheca canis* in the no predator treatment was 4.09 with a sample size of 24 individuals. In 10,000 bootstrap replicates of n=24 from the data from the 2018 *Am Nat* paper, no single estimate of the variance was below 40. See the blow below, where the vertical red line is the observed variance from 2020 Oikos and the histogram shows the distribution of bootstrap estimates: ![file] Ideally, the raw data underlying the article entitled, ** Physiology underlies the assembly of ecological communities ** published in 2018 in *PNAS*, could be used to make comparisons across the other species besides *Epitheca*but unfortunately that data were not uploaded when the paper was published. In the supplementary data for that PNAS paper, it is unfortunately the case that while means and sample sizes were given, variances or SDs were not: ![file] Here are my specific questions for the author: 1.tWhat month year was the study conducted? Again, apologies if I missed this. 2.tWhat specific ponds (i.e., precise geographic locations) were the study animals collected from. Were these the same or different from previous studies? 3.tCan the author offer a methodological explanation of why such stark differences in variance are observed among studies in spite of them having identical means? In particular, I would be grateful if the data for the eight different ponds measured in the Am Nat paper could be uploaded on Dryad so that comparisons of variance could be made. Also the data from the PNAS paper would be useful to add a comparison of other species besides *E stricta*. 4.tI would like to know if, in the raw data of surveys of different ponds, the author observes such appreciable differences in variance between the ponds that have the same mean. If this was the case, it would be an easy explanation for the finding of different variances. , 
 A Twitter user familiar with activity measurements in dragonflies has pointed out that the data are quite dissimilar from anything he s collected before. https: twitter.com joacim_naslund status 1301272546810224642 , 
 A colleague pointed out a possible flaw in the above bootstrap analysis by Bombus apollineus because it should have also bootstrapped the distribution of the estimate from the OIKOS study. I did this and found that the maximum variance observed in 10K bootstrap estimates was 7.64. Therefore, bootstrapping the Oikos variance estimate as well does not in any way result in overlapping bootstrap intervals. Other explanations such as sampling populations of different variance, remains a possibility. Here is a quick screen grab of a base histogram of all 10K estimates: ![file] , 
 See also https: retractionwatch.com 2021 05 03 ecologist-who-lost-thesis-awards-earns-expressions-of-concern-after-laptop-stolen ,