Anemia, Hemolytic, Congenital Nonspherocytic ; Erythrocytes ; Humans ; Pyruvate Kinase/deficiency* ; Pyruvate Metabolism, Inborn Errors

OBJECTIVE: To investigate the effect of glycolytic enzyme pyruvate kinase type 2 (PKM2) on the proliferation and apoptosis of human leukemia HL-60 cells. METHODS: si-PKM2 plasmid was transfected into HL-60 cells (set as si-PKM2 group), and blank vector transfected cells were set as control group (si-Ctl group). The expression levels of PKM2 mRNA and protein in si-Ctl group and si-PKM2 group were detected by RT-qPCR and Western blot. CCK-8 cell detection kit was used to detect the proliferation ability of the cells in the two groups. Flow cytometry was used to detect the changes of cell cycle and apoptosis. Western blot and RT-qPCR were used to detect the changes of p-Akt and p-mTOR protein levels in PI3K/Akt/mTOR signaling pathway and the changes of glycolysis-related mRNA levels of the cells in the two groups. The changes in glucose consumption and lactic acid production of the cells were assayed. Over expressed PKM2, HL-60 cells were treated with PI3K inhibitor LY294002 or galactose, the changes in cell proliferation ability, cell cycle and apoptosis, as well as changes in glucose consumption and lactic acid production were detected. RESULTS: Interfered by si-PKM2, mRNA and protein levels of PKM2 in si-PKM2 group significantly decreased, and proliferation ability of the cells was also reduced (P<0.05). After PKM2 knockdown, the cells were significantly blocked at G CONCLUSION PKM2 knockdown can inhibit the proliferation and induce apoptosis of HL-60 cells, and its molecular mechanism may be related to the PKM2-mediated PI3K/Akt/mTOR-glycolysis, which suggesting that PKM2 may serve as a molecular target for the prevention and treatment of leukemia.
Apoptosis ; Cell Proliferation ; Glycolysis ; Humans ; Phosphatidylinositol 3-Kinases/metabolism* ; Pyruvate Kinase

OBJECTIVETo explore the molecular mechanism of erythrocyte pyruvate kinase deficiency (PKD).

METHODSTargeted sequence capture and next-generation sequencing (NGS) were used to detect the regions of exon and exon-intron boundarie of PKLR gene in a clinical suspected PKD patient. The protein function of mutant gene was forecasted by the SIFT and PolyPhen-2 databank, after the mutation of PKLR gene in the patient was detected by the NGS technology, its genotype was confirmed by Sanger sequencing.

RESULTSThe patient was found to have peculiar double heterozygous mutations: 661 G>A (Asp221Asn) of exon 5 and 1528 C>T (Arg510Ter) of exon 10, resulting in amino acid substitution Asp221Asn and Arg510Ter, these mutations were also further confirmed by Sanger sequencing. The complex mutations were infrequent and each of them was able to cause diseases.

CONCLUSIONThe complex mutations of both 661 G>A and 1528 C>T of PKLR gene are the molecular mechanism of PKD. Simultaneous existance of above-mentioned complex mutations in PDK patient was never been previously reported at home and abroad.

Anemia, Hemolytic, Congenital Nonspherocytic ; genetics ; Exons ; Genotype ; High-Throughput Nucleotide Sequencing ; Humans ; Introns ; Mutation ; Pyruvate Kinase ; deficiency ; genetics ; Pyruvate Metabolism, Inborn Errors ; genetics

OBJECTIVETo screen potential mutation and explore the underlying mechanism for a consanguineous pedigree featuring pyruvate kinase (PK) deficiency.

METHODSThe red blood cell pyruvate kinase activities of all family members were detected. All the exons and intron-exon boundaries of the PKLR gene for the proband were amplified and analyzed by direct sequencing. Restriction endonuclease enzymes were used to identify the presence of mutations of all family members.

RESULTSThe pyruvate kinase activities were 5.89 U/g Hb in the proband, 3.45, 6.54, 8.87, 7.89, 9.32 U/g Hb in his younger sister, father, mother, grandmother and elder aunt, respectively. The homozygous missense mutation of T>C transition at position 941 in exon 7 of PKLR gene resulted to a Ile314Thr substitution in the proband, and mutant alleles were identified at the level of RNA transcript by cDNA sequence analysis. His younger sister was also homozygous for Ile314Thr. Heterozygosity for Ile314Thr was confirmed in his grandmother, parents and elder aunt.

CONCLUSIONIle314Thr homozygous missense mutation in exon 7 of PKLR is the molecular mechanism of pyruvate kinase deficiency in this family.

Anemia, Hemolytic, Congenital Nonspherocytic ; genetics ; Child, Preschool ; Female ; Humans ; Male ; Pedigree ; Point Mutation ; Pyruvate Kinase ; deficiency ; genetics ; Pyruvate Metabolism, Inborn Errors ; genetics

OBJECTIVETo evaluate the clinical significance of blood and fecal expression of tumor M2-pyruvate kinase (Tumor M2-PK) in patients with colorectal cancer.

METHODSWith 22 healthy subjects as controls, 44 patients with CRC were examined for tumor M2-PK in serum and fecal samples using a sandwich enzyme immunoassay.

RESULTSThe sensitivity of serum and fecal tumor M2-PK for detecting CRC was 59.1% and 63.6% with a specificity of 86.4% and 81.8%, respectively. The serum and fecal levels of tumor M2-PK showed a significant correlation in CRC patients.

CONCLUSIONTumor M2-PK has good sensitivity and specificity in the diagnosis of CRC.

Biomarkers, Tumor ; metabolism ; Case-Control Studies ; Colorectal Neoplasms ; blood ; metabolism ; Feces ; enzymology ; Female ; Humans ; Male ; Pyruvate Kinase ; blood ; metabolism

OBJECTIVETo investigate the effects of hypoxia on the glycolysis in cultured rat hepatocytes.

METHODSMixed gas with different concentrations of O(2), CO(2) and N(2) was prepared for the in vitro culture of normal rat hepatocytes. The cell strains were set to be A, B, C groups, which were observed at 1, 2, 4, 8 and 16 hours after hypoxia with normal hepatocytes as the control. Biochemical methods were employed to determine the activities of the key enzymes during hepatocytic glycolysis such as hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH) and the change of the content of lactic acid (LA) in the culture fluid.

RESULTS(1) The LDH activity of the rat hepatocytes increased significantly at all the time points of hypoxia in A and B groups when compared with that in control group (P < 0.05), while the activity increased obviously in C group since 2 hours after hypoxia (P < 0.05). (2) The HK activity of the cells in A group increased significantly at 1, 2, 4 and 16 hours after hypoxia and that in B and C groups increased obviously at 1 hour when compared with control group (P < 0.05). While the cellular PFK activity in A group increased markedly at 1 and 4 hours after hypoxia and that in B and C groups increased evidently at 4 hours after hypoxia (P < 0.05). The cellular PK activity in all the three groups increased at all the hypoxic time points (P < 0.05). (3) The cellular LA content in A and B groups began to increase since 2 hours and that in C group did so since 4 hours after hypoxia and increased along with the time lapse (P < 0.05).

CONCLUSIONhypoxia might initiate glycolysis.

Animals ; Cell Hypoxia ; Cells, Cultured ; Glycolysis ; Hepatocytes ; enzymology ; metabolism ; Hexokinase ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lactic Acid ; metabolism ; Oxygen ; metabolism ; Phosphofructokinases ; metabolism ; Pyruvate Kinase ; metabolism ; Rats

OBJECTIVETo evaluate the feasibility of genetic and prenatal diagnosis for a family affected with pyruvate kinase deficiency (PKD).

METHODSTargeted sequence capture and high-throughput sequencing technology was used to detect the exons and exon-intron boundaries of the PKLR gene in a clinically suspected PKD patient. Meanwhile, the genotype of the pedigree was validated by Sanger sequencing. Prenatal genetic diagnosis was performed by amniotic fluid sampling after genotype of the mother of the proband was determined.

RESULTSThe proband was found to harbor double heterozygous mutations, c.661G>A (Asp221Asn) and c.1528C>T (Arg510Ter), which resulted in amino acid substitution Asp221Asn and Arg510Ter. Such mutations were confirmed by Sanger sequencing. The mother and father of the proband were detected to have respectively carried c.1528C>T (Arg510Ter) and c.661G>A (Asp221Asn) mutation. The fetus was found to have carried the same mutations as the proband. Following selected abortion, analysis of fetal tissue was consistent with the result of prenatal diagnosis.

CONCLUSIONThe compound mutations of c.661G>A and c.1528C>T of PKLR gene probably underlie the PKD in the family. Prenatal diagnosis of the mutations analysis can facilitate detection of affected fetus in time.

Adult ; Anemia, Hemolytic, Congenital Nonspherocytic ; embryology ; enzymology ; genetics ; Base Sequence ; Child, Preschool ; DNA Mutational Analysis ; Exons ; Female ; Genotype ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Pedigree ; Pregnancy ; Prenatal Diagnosis ; Pyruvate Kinase ; deficiency ; genetics ; metabolism ; Pyruvate Metabolism, Inborn Errors ; embryology ; enzymology ; genetics

A kinetic assay for total calcium in serum was developed which is based on the activation of Ca++-ATPase by free Ca++ [Ca++]f maintained by EGTA in the reaction mixture. The concentration of Caf++ was dependent on total reference calcium added or serum calcium. Ca++-ATPase activity was coupled to the reduction of NADH by pyruvate kinase (PK) and lactate dehydrogenase (LDH) and monitored by change in absorbance at 340 nm. The calcium in normal serum was 10.08 +/- 0.24 mg/ dl (n = 35) by our method while with o-cresolphthalein complexone (CPC) method, the total calcium in the same 35 serum samples was 10.14 +/- 0.54 mg/dl. The range of within-run coefficient of variations (CVs) by this method was 0.9-2.87% at 8-12 mg/dl and day-to-day CVs were 0.72-3.17%. The presence of other ions and standard clinical interfering agents did not affect this assay system. The correlation between values obtained with our method (y) and CPC method (x) for normal serum was: y = 1.064x-0.580 mg/dl (r = 0.912, n = 59).
Adenosinetriphosphatase/metabolism ; Adolescent ; Adult ; Calcium/*blood ; Comparative Study ; Enzyme Activation ; Female ; Human ; Kinetics ; Male ; NAD/metabolism ; Pyruvate Kinase/metabolism ; Reference Standards ; Reproducibility of Results ; Sensitivity and Specificity

OBJECTIVETo investigate the gene expression profiles in lung adenocarcinoma (LA), tumor adjacent tissue (TAT) and fetal lung tissue (FLT) by cDNA microarray technique.

METHODSTotal RNA from LA, TAT and FLT was extracted and purified. The cDNA was made by RT-PCR, and then labeled with Cy5 and Cy3 fluorescence as probes which were hybridized with the whole gene chips. Subsequently, the signal images were scanned by ScanArray 4000 fluorescence scanner and analyzed by Gene Pix PRO3.0.

RESULTSIn 4 cases with LA and TAT, 25 genes were screened out for differences in gene expression level, among which 3 were upregulated and 22 downregulated; in FLT and TAT cases, 316 genes were screened out, among which 192 were upregulated and 124 downregulated; 16 genes were found to be differentially expressed genes in common in LA, TAT and FLT, among which 12 were upregulated and 4 downregulated.

CONCLUSIONThe 25 differentially expressed genes in LA and TAT may be related to occurrence and development of lung cancer, while the 316 genes in FLT and TAT may be related to fetal developmental. The 16 differentially expressed genes may be related to the initiation of lung cancer.

Adenocarcinoma ; genetics ; metabolism ; Fetal Development ; genetics ; Fetus ; Gene Expression Profiling ; Humans ; Interleukin-6 ; metabolism ; Lung ; metabolism ; Lung Neoplasms ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; Oncogenes ; genetics ; Pyruvate Kinase ; metabolism ; Receptors, CXCR4 ; metabolism ; Thioredoxin-Disulfide Reductase ; metabolism

Pyruvate kinase catalyzes the rate-limiting final step of glycolysis, generating adenosine triphosphate (ATP) and pyruvate. The M2 tumor-specific isoform of pyruvate kinase (PKM2) promotes glucose uptake and lactate production in the presence of oxygen, known as aerobic glycolysis or the Warburg effect. As recently reported in Nature, PKM2, besides its metabolic function, has a nonmetabolic function in the direct control of cell cycle progression by activating β-catenin and inducing expression of the β-catenin downstream gene CCND1(encoding for cyclin D1). This nonmetabolic function of PKM2 is essential for epidermal growth factor receptor (EGFR) activation-induced tumorigenesis.
Animals ; Cell Cycle ; Cell Proliferation ; Cell Transformation, Neoplastic ; Cyclin D1 ; metabolism ; Glycolysis ; Humans ; Isoenzymes ; metabolism ; Neoplasms ; metabolism ; pathology ; Pyruvate Kinase ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; beta Catenin ; metabolism