摘要
Growing evidence suggests that somatic hypermutational status and programmed cell death-1 overexpression are potential predictive biomarkers indicating treatment benefits from immunotherapy using immune checkpoint inhibitors.However,biomarker-matched trials are still limited,and many of the genomic alterations remain difficult to target.To isolate the potential somatic hypermutational tumor from microsatellite instability low/microsatellite stability(MSI-L/MSS)cases,we employed two commercial kits to determine MSI and forensic short tandem repeat(STR)alternations in 250 gastrointestinal(GI)tumors.Three types of forensic STR alternations,namely,allelic loss,Aadd,and Anew,were identified.62.4%(156/250)of the patients with GI exhibited STR alternation,including 100%(15/15)and 60%(141/235)of the microsatellite high instability and MSI-L/MSS cases,respectively.30%(75/250)of the patients exhibited STR instability with more than 26.32%(26.32%–84.21%)STR alternation.The cutoff with 26.32%of the STR alternations covered all 15 MSI cases and suggested that it might be a potential threshold.Given the similar mechanism of the mutations of MSI and forensic STR,the widely used forensic identifier STR kit might provide potential usage for identifying hypermutational status in GI cancers.
基金
supported by the grants from National Key Research and Development Program of China(Nos.2016YFA0500600 and 2016YFC0800703)
the National Science Fund for Distinguished Young Scholars(No.81625013)
General Program of National Natural Science Foundation of China(No.81772028)
The funders had no role in study design,data analysis,publishing decisions,or manuscript preparation.
