OBJECTIVE: To explore the effect of UVRAG on mitophagy in leukemia cells K562. METHODS: K562 cells were induced with different concentrations of mitophagy inducer carbonylcyanide-m-chlorophenylhydrazone (CCCP) for 6, 12 and 24 hours, and the cell viability was detected by the CCK-8 assay. K562 cells were divided into NC, UVRAG-siRNA, UVRAG-siRNA+CCCP, and CCCP group, while Western blot was used to detect the expression of UVRAG protein. Flow cytometry was used to detect the changes in reactive oxygen species (ROS) and mitochondrial structural integrity. The expressions of autophagy related proteins P62 and LC3-Ⅱ/LC3-Ⅰ were detected by Western blot. RESULTS: Compared with NC group, the expression of UVRAG protein in UVRAG -siRNA group significantly decreased (P<0.01). Compared with CCCP group, in UVRAG -siRNA+CCCP group ROS, mitochondrial structure damage, and the expression of LC3-Ⅱ/LC3-Ⅰ decreased significantly (P<0.05, P<0.05, P<0.01), while the expression of P62 protein increased (P<0.05). Compared with NC group, the differences in the expressions of P62 and LC3-Ⅱ/LC3-Ⅰ protein, ROS, and mitochondrial structural integrity in UVRAG -siRNA group were not obvious (P>0.05). CONCLUSION Under the treatment of CCCP, silencing UVRAG can inhibit mitophagy in K562 cells.
Humans ; Leukemia ; Tumor Suppressor Proteins

As a pro-apoptotic factor, prostate apoptosis response protein 4 (par-4) was first found in the male hormone-dependent prostate cells (AT-3). Endogenous Par-4 sensitizes cancer cells to apoptotic stimuli, but exogenous Par-4 selectively induces apoptosis in cancer cells, and these activities depends on the structure of its core domain SAC. Par-4 and SAC can specifically induce apoptosis of cancer cells but not of normal cells, and are therefore potential anti-cancer drugs. In this review we summarize the discovery, structure, and function of par-4, and its intracellular signaling pathways, then discuss the application prospects of Par-4 and SAC in the clinical treatment of cancer and the problems in its research and clinical applications.
Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Humans ; Tumor Suppressor Proteins

Humans ; Leukemia, Myeloid, Acute ; Molecular Chaperones ; Tumor Suppressor Proteins

OBJECTIVETo investigate the hypermethylation status of blu gene promoter in nasopharyngeal NK/T cell lymphoma and its role in the tumorigenesis and molecular diagnosis of this lymphoma.

METHODSTwenty cases of paraffin-embedded nasopharyngeal NK/T cell lymphomas tissues were studied by using methylation specific PCR (MSP).

RESULTSHypermethylation of blu gene promoter is detected in 6 of 20 (30%) nasopharyngeal NK/T cell lymphoma. The 6 positive cases were 4 in 15 nasopharyngeal NK cell lymphomas, 1 of 2 NK like T cell lymphoma and 1 in 3 peripheral T cell lymphomas (unspecified type).

CONCLUSIONHypermethylation of blu gene promoter in nasopharyngeal NK/T cell lymphoma indicated the inactivation of blu gene and its possible role in the tumorigenesis of this lymphoma. blu gene methylation could be detected in paraffin-embedded tissue and used as a new molecular marker for the diagnosis of this lymphoma.

DNA Methylation ; Genes, Tumor Suppressor ; Humans ; Lymphoma ; genetics ; pathology ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Polymerase Chain Reaction ; methods ; Tumor Suppressor Proteins

OBJECTIVE: To screen for small molecular compounds with selective inhibitory activity against cutaneous melanoma cells with BAP1 deletion. METHODS: Cutaneous melanoma cells expressing wild-type BAP1 were selected to construct a BAP1 knockout cell model using CRISPR-Cas9 system, and small molecules with selective inhibitory activity against BAP1 knockout cells were screened from a compound library using MTT assay. Rescue experiment was carried out to determine whether the sensitivity of BAP1 knockout cells to the candidate compounds was directly related to BAP1 deletion. The effects of the candidate compounds on cell cycle and apoptosis were detected with flow cytometry, and the protein expressions in the cells were analyzed with Western blotting. RESULTS: The p53 activator RITA from the compound library was shown to selectively inhibit the viability of BAP1 knockout cells. Overexpression of wild-type BAP1 reversed the sensitivity of BAP1 knockout cells to RITA, while overexpression of the mutant BAP1 (C91S) with inactivated ubiquitinase did not produce any rescue effect. Compared with the control cells expressing wild-type BAP1, BAP1 knockout cells were more sensitive to RITA-induced cell cycle arrest and apoptosis (P < 0.0001) and showed an increased expression of p53 protein, which was further increased by RITA treatment (P < 0.0001). CONCLUSION Loss of BAP1 results in the sensitivity of cutaneous melanoma cells to p53 activator RITA. In melanoma cells, the activity of ubiquitinase in BAP1 is directly related to their sensitivity to RITA. An increased expression of p53 protein induced by BAP1 knockout is probably a key reason for RITA sensitivity of melanoma cells, suggesting the potential of RITA as a targeted therapeutic agent for cutaneous melanoma carrying BAP1-inactivating mutations.
Humans ; Melanoma ; Skin Neoplasms ; Tumor Suppressor Protein p53 ; Apoptosis ; Cell Division ; Tumor Suppressor Proteins/genetics* ; Ubiquitin Thiolesterase/genetics*

The transcriptional coactivator MN1 has been identified as a gene overexpressed in certain types of human acute myeloid leukemia. Overexpression of this gene is associated with all inv (16) AML, retinoic acid-resistance, a worse prognosis as well as a shorter survival in AML patients with a normal karyotype. This article reviews the role of MN1 in acute myeloid leukemia including MN1 gene structure and action mechanism, MN1-TEL and AML with normal karyotype, MN1 and inv (16) AML, MN1 and retinoic ocid-resistance, and so on.
Humans ; Leukemia, Myeloid, Acute ; genetics ; Oncogene Proteins, Fusion ; genetics ; Transcription Factors ; genetics ; Tumor Suppressor Proteins ; genetics

Glioblastoma ; genetics ; metabolism ; Humans ; Mutation ; Oncogene Proteins ; genetics ; metabolism ; Tumor Suppressor Proteins ; genetics ; metabolism

Animals ; Binding Sites ; Cochlea ; Homeodomain Proteins/chemistry* ; Mice ; Transcription Factors ; Tumor Suppressor Proteins/chemistry*

To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder tissues and 23 specimens of bladder transitional cell carcinoma (BTCC). The promoter methylation in BTCC and normal bladder tissues was detected by methylation-specific PCR (MSP). The results showed that the expression level of RASSF1A protein was significantly lower in BTCC tissues than that in normal bladder tissues. However, it was not correlated with its clinical stages and pathological grades. The frequency of promoter methylation of RASSF1A gene was higher in BTCC tissues than that in normal bladder tissues. In 14 patients with the aberrant promoter methylation, 13 showed loss or low expression of RASSF1A protein. It is concluded that RASSF1A gene promoter methylation may contribute to the low level or loss of RASSF1A protein expression, the inactivation of RASSF1A gene and the genesis of BTCC. But, it may bear no correlation with its clinical stages and pathological grades.
Blotting, Western ; Carcinoma, Transitional Cell/metabolism ; DNA Methylation ; DNA Primers/chemistry ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Promoter Regions, Genetic ; Tumor Suppressor Proteins/*biosynthesis ; Tumor Suppressor Proteins/*genetics ; Urinary Bladder Neoplasms/*metabolism

The gastrointestinal tract is the largest digestive organ and the largest immune organ and detoxification organ, which is vital to the health of the body. Drosophila is a classic model organism, and its gut is highly similar to mammalian gut in terms of cell composition and genetic regulation, therefore can be used as a good model for studying gut development. target of rapmaycin complex 1 (TORC1) is a key factor regulating cellular metabolism. Nprl2 inhibits TORC1 activity by reducing Rag GTPase activity. Previous studies have found that nprl2 mutated Drosophila showed aging-related phenotypes such as enlarged foregastric and reduced lifespan, which were caused by over-activation of TORC1. In order to explore the role of Rag GTPase in the developmental defects of the gut of nprl2 mutated Drosophila, we used genetic hybridization combined with immunofluorescence to study the intestinal morphology and intestinal cell composition of RagA knockdown and nprl2 mutated Drosophila. The results showed that RagA knockdown alone could induce intestinal thickening and forestomach enlargement, suggesting that RagA also plays an important role in intestinal development. Knockdown of RagA rescued the phenotype of intestinal thinning and decreased secretory cells in nprl2 mutants, suggesting that Nprl2 may regulate the differentiation and morphology of intestinal cells by acting on RagA. Knockdown of RagA did not rescue the enlarged forestomach phenotype in nprl2 mutants, suggesting that Nprl2 may regulate forestomach development and intestinal digestive function through a mechanism independent of Rag GTPase.
Animals ; Drosophila/genetics* ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Mammals/metabolism* ; Carrier Proteins ; Tumor Suppressor Proteins/metabolism* ; Drosophila Proteins/genetics*