Identification of TMEM217 as a novel prognostic biomarker and potential therapeutic target in acute myeloid leukemia

Despite remarkable advances in molecular and cell biology of acute myeloid leukemia(AML),AML patients still frequently relapse and have low 5-year overall survival(OS)rates.1 It is worth noting that a recent study from the registry or clinical trial compilation has reported an improvement in the OS of adult AML patients,especially those under 60 years of age.

Palmitoylation of GNAQ/11 is critical for tumor cell proliferation and survival in GNAQ/11-mutant uveal melanoma

More than 85%of patients with uveal melanoma(UM)carry a GNAQ or GNA11 mutation at a hotspot codon(Q209)that encodes G proteinαsubunit q/11 polypeptides(Gα_(q/11)).GNAQ/11 relies on palmitoylation for membrane association and signal transduction.Despite the palmitoylation of GNAQ/11 was discovered long before,its implication in UM remains unclear.Here,results of palmitoylation-targeted mutagenesis and chemical interference approaches revealed that the loss of GNAQ/11 palmitoylation substantially affected tumor cell proliferation and survival in UM cells.Palmitoylation inhibition through the mutation of palmitoylation sites suppressed GNAQ/11^(Q209L)-induced malignant transformation in NIH3T3 cells.Importantly,the palmitoylation-deficient oncogenic GNAQ/11 failed to rescue the cell death initiated by the knock down of endogenous GNAQ/11 oncogenes in UM cells,which are much more dependent on Gα_(q/11) signaling for cell survival and proliferation than other melanoma cells without GNAQ/11 mutations.Furthermore,the palmitoylation inhibitor,2-bromopalmitate,also specifically disrupted Gα_(q/11) downstream signaling by interfering with the MAPK pathway and BCL2 survival pathway in GNAQ/11-mutant UM cells and showed a notable synergistic effect when applied in combination with the BCL2 inhibitor,ABT-199,in vitro.The findings validate that GNAQ/11 palmitoylation plays a critical role in UM and may serve as a promising therapeutic target for GNAQ/11-driven UM.

DDB1-and CUL4-associated factor 8 plays a critical role in spermatogenesis

Cullin-RING E3 ubiquitin ligase(CRL)-4 is a member of the large CRL family in eukaryotes.It plays important roles in a wide range of cellular processes,organismal development,and physiological and pathological conditions.DDB1-and CUL4-associated factor 8(DCAF8)is a WD40 repeat-containing protein,which serves as a substrate receptor for CRL4.The physiological role of DCAF8 is unknown.In this study,we constructed Dcaf8 knockout mice.Homozygous mice were viable with no noticeable abnormalities.However,the fertility of Dcaf8-deficient male mice was markedly impaired,consistent with the high expression of DCAF8 in adult mouse testis.Sperm movement characteristics,including progressive motility,path velocity,progressive velocity,and track speed,were significantly lower in Dcaf8 knockout mice than in wild-type(WT)mice.However,the total motility was similar between WT and Dcaf8 knockout sperm.More than 40%of spermatids in Dcaf8 knockout mice showed pronounced morphological abnormalities with typical bent head malformation.The acrosome and nucleus of Dcaf8 knockout sperm looked similar to those of WT sperm.In vitro tests showed that the fertilization rate of Dcaf8 knockout mice was significantly reduced.The results demonstrated that DCAF8 plays a critical role in spermatogenesis,and DCAF8 is a key component of CRL4 function in the reproductive system.