Since the former assay is quite complex, many have resorted to generating drug-resistant tumor xenografts to address the potential role of the stroma in driving resistance. variants that drive resistance using adherent lines. were Rabbit Polyclonal to TBL2 observed in or (Tables 2 and 3). Alternatively, if cell lines of interest do not exist bearing defects in MMR, BC 11 hydrobromide acute treatment with physical or DNA reactive chemical mutagens such as the alkylating agent vs selection have been verified to be clinically relevant, there exists a possibility that this mechanisms may not serve as relevant or predominant mechanisms of clinical resistance. One reason for this may include an essential role for the micro-environment in driving resistance to therapy, a component that is devoid in the experimental protocol/setup discussed thus far. Indeed, several studies have shown that anti-cancer brokers that are capable of killing tumor cells are rendered ineffective when the tumor cells are cultured in the presence of stromal cells implying innate mechanisms of resistance conferred by the stroma37,38. To identify such stroma-induced acquired resistance mechanisms, one may consider performing co-culture or tumor resistance assays. Since the former assay is quite complex, many have resorted to generating drug-resistant tumor xenografts to address the potential BC 11 hydrobromide role of the stroma in driving resistance. Such studies have uncovered both identical5 and unique39 mechanisms of resistance relative to selection, implying that this stroma may indeed play a role in the latter. However, one must be mindful of the length of time it may take to generate such resistant tumors and the complexity of the follow-up genomic analysis-complexities due to the intra-tumoral molecular and cellular heterogeneity. em Target identification /em In addition to uncovering drug resistance mechanisms, this NGS-based genomic profiling approach can also be applied to identify cellular targets of chemical probes. Historically, multiple unbiased methods have been used to identify the cellular mechanisms of action and targets of low-molecular BC 11 hydrobromide weight chemicals with biological activities, including affinity purification coupled with quantitative proteomics, yeast genomic methods, RNAi screening, and BC 11 hydrobromide computational inference approaches40. As an extension to elucidation of drug-resistance mechanisms using NGS-based genomic or transcriptomic profiling of phenotypically resistant cell populations, identification of unique recurrent single nucleotide variations (SNVs) or expression alterations that enable resistance can offer insights into functional cellular targets of compounds. This is based on the idea that a subset of resistance mechanisms observed may involve recurrent mutations in genes that encode the direct protein targets of the small molecule. Recently, several reports validated the utility of the approach, particularly by combining with other approaches including large-scale cancer cell line sensitivity profiling, BC 11 hydrobromide to revealing the cellular targets of small-molecule probes9,10. Disclosures Publication fees for this article are paid by H3 Biomedicine. Acknowledgments The authors would like to acknowledge our colleagues at H3 Biomedicine for their feedback during the manuscript preparation..