diff --git a/vignettes/TET2.Rmd b/vignettes/TET2.Rmd index a79f410..380c9a0 100644 --- a/vignettes/TET2.Rmd +++ b/vignettes/TET2.Rmd @@ -12,6 +12,10 @@ vignette: > --- ```{r setup, include=FALSE} + +BiocManager::install("GEOquery") +BiocManager::install("limma") + knitr::opts_chunk$set(echo = TRUE) knitr::opts_chunk$set(collapse = TRUE, comment = "#>") library(devtools) @@ -45,6 +49,9 @@ details can be found in [the paper](https://doi.org/10.1016/j.ccr.2010.11.015), which is indeed a landmark. Nevertheless, some fine details of the work seemed to disagree with the results of other cohorts when replication was attempted. +#To be accurate, all of the 2021 cohort members were very much so alive prior +#to 2010 + ![The money shot](figure/TET2.png) Some of you who have seen volcano plots before can guess where this is going. @@ -77,10 +84,16 @@ if (FALSE) { # this takes about 5 minutes: # how many probes, how many patients? dim(DNAme) -# Features Samples -# 25626 394 - +# Features Samples +# 25626 394 ``` +#^^note:features==probes, samples==patients +#^^This output indicates that only 25,626 CpG sites are available for analysis, +#though the original paper reports testing ~50,000 sites. Why is there such a +#discrepancy? +#Also, the original paper excludes 15 of 398 patients for analysis, yet there +#are still 394 patients included in the dataframe. Why are there not 385 +#patients included, as reported in the paper? ### Some contrasts @@ -151,3 +164,54 @@ fit3 <- eBayes(lmFit(exprs(DNAme)[, as.integer(rownames(design3))], design3)) # 10 probes for TET2:purity ``` +#Paige's code review: + 1)The following additions were necessary in the first chunk of code: + A) BiocManager::install("GEOquery") + B) BiocManager::install("limma") +2)Comments on quality of code logic, accompanying text, labels: + A) Though I am unfamiliar with some of the functions used in the current + code, I was able to follow the logic decently well. + B) I would have made changes to the text accompanying the code output in + the section, "Do we see genome-wide hypermethylation from TET2 + mutations?" to indicate that the number of probes corresponds to the + number of CpG sites hypermethylated in samples harboring a specific + type of mutation. + C) Regarding labels: I would have preferred no labels on the x-axis of + the heatmap; it was rather distracting trying to figure out what the + small, inscrutable black text meant. + +#Paige's science review: + 1) Assumptions regarding the term "probe": + A) I assume a "probe" is one of the ~50,000 CpG sites + that the authors looked at in the paper. + B) I also assume that "6513 probes for IDH" (for example) infers that + the same 6513 CpG islands are mutated across all samples harboring an + IDH mutation. + i) Should (B) be the case, indicating the same 6513 sites are + preferentially hypermethylated in AML patients harboring IDH + mutations should be indicated in the text accompanying the code. + 2) Mutually exclusive TET2 and IDH1/2 mutations: + According to the heatmap provided (under #always plot your data), + it is evident that IF either IDH1/2 or TET2 mutations are present in the AML + patients, these mutations LARGELY occur mutually exclusive of each other. + However, it should be noted that most of the samples harbored neither mutation. + Additionally,the heatmap also demonstrates a small population of samples that + harbor both mutations.Therefore, it is misleading to say these mutations are + mutually exclusive. + A) Question: If the vast majority of the samples extracted from these AML + patients do not harbor either mutation, is this really a defining + feature of AML? + 3) Hypermethylation profiles and IDH and TET2 mutations: + The 6500+ hits for methylated CpG sites in IDH mutated-samples vs. + the ~10 hits for the TET2 mutated-samples indicates that these mutations have + differential associations with hypermethylation at CpG sites. It is misleading + for the authors to indicate that both kinds of mutations engender "overlapping" + hypermethylation signatures, considering that even if all TET2-related sites + overlapped with the IDH-related sites, this only represents 0.15% of all + sites implicated by IDH mutation. Also, hypermethylation at ~10 CpG spots (in + the context of TET2 mutation) is not sufficient to constitute a + genome-wide hypermethylation profile.Therefore, it seems IDH mutation has a + larger association with hypermethylation profiles, while TET2 mutation has a + minimal association with hypermethylation profiles. + + \ No newline at end of file