Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of gen...Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of genetic vulnerability for UM,we found that inhibition of euchromatic histone lysine methyltransferase 2(EHMT2)expression or activity significantly reduced the proliferation and migration capacity of cancer cells.Notably,elevated expression of EHMT2 had been validated in UM samples.Furthermore,Kaplan-Meier survival analysis indicated high EHMT2 protein level was related to poor recurrence-free survival and a more advanced T stage.Chromatin immunoprecipitation sequencing analysis and the following mechanistic investigation showed that ARHGAP29 was a downstream target of EHMT2.Its transcription was suppressed by EHMT2 in a methyltransferasedependent pattern in GNAQ/11-mutant UM cells,leading to elevated RhoA activity.Rescuing constitutively active RhoA in UM cells lacking EHMT2 restored oncogenic phenotypes.Simultaneously blocking EHMT2 and GNAQ/11 signaling in vitro and in vivo showed a synergistic effect on UM growth,suggesting the driver role of these two key molecules.In summary,our study shows evidence for an epigenetic program of EHMT2 regulation that influences UM progression and indicates inhibiting EHMT2 and MEK/ERK simultaneously as a therapeutic strategy in GNAQ/11-mutant UM.展开更多
基金supported by the Science and Technology Commission of Shanghai(20DZ2270800,China)the National Natural Science Foundation of China(grants 82073889)+1 种基金the Innovative Research Team of High-level Local Universities in Shanghai(SHSMU-ZDCX20210900,China)China Postdoctoral Science Foundation(2022M722120,China)and Shanghai Sailing Program(22YF1422800,China)。
文摘Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of genetic vulnerability for UM,we found that inhibition of euchromatic histone lysine methyltransferase 2(EHMT2)expression or activity significantly reduced the proliferation and migration capacity of cancer cells.Notably,elevated expression of EHMT2 had been validated in UM samples.Furthermore,Kaplan-Meier survival analysis indicated high EHMT2 protein level was related to poor recurrence-free survival and a more advanced T stage.Chromatin immunoprecipitation sequencing analysis and the following mechanistic investigation showed that ARHGAP29 was a downstream target of EHMT2.Its transcription was suppressed by EHMT2 in a methyltransferasedependent pattern in GNAQ/11-mutant UM cells,leading to elevated RhoA activity.Rescuing constitutively active RhoA in UM cells lacking EHMT2 restored oncogenic phenotypes.Simultaneously blocking EHMT2 and GNAQ/11 signaling in vitro and in vivo showed a synergistic effect on UM growth,suggesting the driver role of these two key molecules.In summary,our study shows evidence for an epigenetic program of EHMT2 regulation that influences UM progression and indicates inhibiting EHMT2 and MEK/ERK simultaneously as a therapeutic strategy in GNAQ/11-mutant UM.
