Analysis of clinical features and genetic variant in a neonate with Au-Kline syndrome due to a de novo variant of the HNRNPK gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical phenotype and genetic basis of a neonate with Au-Kline syndrome (AKS).@*METHODS@#Clinical data and result of genetic testing of a neonate with AKS who was admitted to the Affiliated Provincial Children's Hospital of Anhui Medical University in January 2021 were retrospectively analyzed. Relevant literature was searched from the Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure and PubMed databases using key words "Au Kline syndrome", "Au-Kline syndrome", "HNRNPK" and "AKS". The research period was set as from January 1, 2000 to December 31, 2020.@*RESULTS@#The male newborn has manifested feeding difficulties, hypotonia, absence of the upper jaw to the uvula and facial dysmorphism. Trio-whole exome sequencing revealed that he has harbored a frameshift c.478dupA (p.Ile160AsnfsTer7) variant of the HNRNPK gene, which was varified by Sanger sequencing to have a de novo origin. The variant has not been included in the databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was rated as pathogenic (PVS1+PS2+PM2_Supporting). Literature retrieval has identified 14 children with AKS and de novo mutations of the HNRNPK gene. Their clinical manifestations have included growth and motor retardation, various degree of mental retardation, facial dysmorphism and a high frequency of congenital heart malformations.@*CONCLUSION@#The AKS in this child may be attributed to the c478dupA frameshifting variant of the HNRNPK gene. Diagnosis of AKS should be suspected for children with mental retardation and multiple congenital malformation syndromes including Kabuki syndrome.

The Effect of hnRNPK/Beclin1 Signaling on the Drug Resistance of Imatinib in Ph+ Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of hnRNPK/Beclin1 signaling on the drug resistance of imatinib in Ph+ leukemia.@*METHODS@#Expression level of hnRNPK was verified in the imatinib resistant and sensitive Ph+ leukemia cell lines by using Western blot. hnRNPK expression was down-regulated by using RNAi. Expression level of LC3I/II and Beclin1 were detected by Western blot and the sensitivity of imatinib was analyzed by CCK-8 assay before and after modulation of hnRNPK expression.@*RESULTS@#hnRNPK showed overexpressed in imatinib resistant leukemia cell line. After the expression level of hnRNPK was down-regulated by RNAi, the sensitivity of drug resistance lines to imatinib restored, while the expression level of LC3I/II and Beclin1 were consistant with the modulation of hnRNPK expression.@*CONCLUSION@#hnRNP K/Beclin1 signaling may be involved in the development of imatinib resistance in Ph+ leukemia through the regulation of autophagy.

ERK1/2-mediated Cytoplasmic Accumulation of hnRNPK Antagonizes TRAIL-induced Apoptosis through Upregulation of XIAP in H1299 Cells / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem.</p><p><b>METHODS</b>Nuclear and cytoplasmic protein extraction and immuno？uorescence (IF) assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K (hnRNPK) localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hnRNPK, GFP-hnRNPK S284/353A, or GFP-hnRNPK S284/353D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR.</p><p><b>RESULTS</b>Previously, we reported that hnRNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK3β phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hnRNPK in H1299 cells. The hnRNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant (GFP-hnRNPK S284/353A) diminish cytoplasmic accumulation of hnRNPK induced by TRAIL. Moreover, we show that XIAP is involved in hnRNPK-mediated TRAIL resistance in H1299 cells.</p><p><b>CONCLUSION</b>Taken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.</p>

Proteomic analysis of novel targets associated with the enhancement of TrkA-induced SK-N-MC cancer cell death caused by NGF

Nerve growth factor (NGF) is known to regulate both cancer cell survival and death signaling, depending on the cellular circumstances, in various cell types. In this study, we showed that NGF strongly upregulated the protein level of tropomyosin-related kinase A (TrkA) in TrkA-inducible SK-N-MC cancer cells, resulting in increases in various TrkA-dependent cellular processes, including the phosphorylation of c-Jun N-terminal kinase (JNK) and caspase-8 cleavage. In addition, NGF enhanced TrkA-induced morphological changes and cell death, and this effect was significantly suppressed by the JNK inhibitor SP600125, but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. To investigate novel targets associated with the enhancement of TrkA-induced SK-N-MC cell death caused by NGF, we performed Coomassie Brilliant Blue staining and two-dimensional (2D) proteomic analysis in TrkA-inducible SK-N-MC cells. We identified 31 protein spots that were either greatly upregulated or downregulated by TrkA during NGF treatment using matrix-associated laser desorption/ionization time of flight/time of flight mass spectrometry, and we analyzed the effects of SP600125 and wortmannin on the spots. Interestingly, 11 protein spots, including heterogeneous nuclear ribonucleoprotein K (hnRNP K), lamin B1 and TAR DNA-binding protein (TDP43), were significantly influenced by SP600125, but not by wortmannin. Moreover, the NGF/TrkA-dependent inhibition of cell viability was significantly enhanced by knockdown of hnRNP K using small interfering RNA, demonstrating that hnRNP K is a novel target associated with the regulation of TrkA-dependent SK-N-MC cancer cell death enhanced by NGF.

Molecular Mechanism of Action of hnRNP K and RTN3 in the Replication of Enterovirus 71 / 病毒学报

Enterovirus 71 (EV71) is a neurotropic pathogen that can induce hand, foot and mouth disease in children. There is an appreciable mortality rate after EV71 infections. The mechanism of action of EV71 replication is not known. Recent work has identified some of cell factors of the host that participate in the synthesis of the RNA and proteins of EV71 (e.g., hnRNP K, reticulon 3 (RTN 3)). In that work, researchers used a competitive assay to show that hnRNP K can interact with EV71 5' UTR, which is required for efficient synthesis of viral RNA. Using a yeast two-hybrid system, other researchers demonstrated that RTN 3 interacts with the N-terminal domain of EV71 2C, which is crucial for replication of viral RNA. Here, we discuss recent work focusing on the molecular mechanisms of hnRNP K and RTN 3 in the synthesis of the RNA and proteins of EV71.

Expression of hnRNPK in gastric carcinoma and its relationship with Helicobacter pylori L-form infection / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the expression feature of heterogeneous nuclear ribonucleoprotein K in gastric carcinoma and its clinical significance, and to explore the relationship between hnRNPK expression and Helicobacter pylori L-form infection.</p><p><b>METHODS</b>The expression of hnRNPK protein was examined in 100 cases of gastric carcinoma, 50 paracancerous gastric tissues and 30 matched normal gastric mucosa by Elivision immunohistochemistry and hnRNPK-mRNA by in situ hybridization. Hp-L was detected with Gram staining and immunohistochemical staining.</p><p><b>RESULTS</b>The positive rates of hnRNPK protein and mRNA in gastric carcinoma were 82.0% and 86.0%, respectively, significantly higher than those in the paracancerous gastric tissues and normal controls (P < 0.05). The expression of hnRNPK protein was significantly correlated with histological differentiation, TNM stage and lymph node metastasis (P < 0.05). The positive rates of Hp-L in the three groups were 67.0%, 58.0% and 23.3%, respectively. The positive rate of Hp-L in gastric carcinoma had no significant correlation with it in the paracancerous gastric tissues, but was significantly higher than it in the normal controls (P < 0.05). In gastric carcinoma, the expression of hnRNPK protein was higher in cases of Hp-L positive patients than those of Hp-L negative cases (P < 0.05). Positive correlation existed between the expression of hnRNPK protein and Hp-L infection (r = 0.391, P < 0.01).</p><p><b>CONCLUSIONS</b>There is a higher expression of hnRNPK in gastric carcinoma. Hp-L infection may be associated with the up-regulated hnRNPK expression. The two factors may play a synergetic role in gastric carcinogenesis.</p>

Preliminary study of proteins related to blast crisis in chronic myeloid leukemia / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To identify and compare the expression profiles of differential proteins between chronic phase and blast crisis in chronic myeloid leukemia (CML) by proteomic analysis, and screen the proteins related to blast crisis.</p><p><b>METHODS</b>The total cellular proteins from the bone marrow cells at chronic phase (CP) and blast crisis (BC) in CML were separated by two-dimensional polyacrylamide gel electrophoresis (2-DE) and analyzed with ImageMaster 5.0 software to screen the differential protein spots. Differential protein spots were identified by mass spectrometry for peptide mass fingerprint in combination with database searching from SWISS-PROT. Then 3 protein spots were selected to verify at protein and mRNA levels by Western blot and semi-quantitative RT-PCR, separately.</p><p><b>RESULTS</b>Comparing gel pages from CML-CP and CML-BC, the expression of 13 protein spots decreased and 25 protein spots increased significantly in CML-BC. Twenty differential protein spots were identified by mass spectrometry and 15 were successfully determined. The results of Western blotting were similar to those of 2-DE and showed a high expression of hnRNPK, annexin A1 and RhoA. Semi-quantitative RT-PCR analysis showed that there was no correlation between the protein expression changes and mRNA levels of hnRNPK, annexin A1 and RhoA.</p><p><b>CONCLUSION</b>A group of proteins associated with blast crisis are obtained and the results may provide clues for further research to elucidate the role of these proteins in CML-BC carcinogenesis and to develop potential associated biomarkers.</p>