OBJECTIVE: To investigate the mechanism of nucleolin (NCL) involved in lymphoma proliferation by regulating thymidine kinase 1 (TK1). METHODS: Twenty-three patients with diffuse large B-cell lymphoma (DLBCL) were selected and divided into initial treatment group (14 cases) and relapsed/refractory group (9 cases). Serum TK1 and C23 protein in peripheral blood mononuclear cells were detected. Cell models of CA46-NCL-KD (CA46-NCL-knockdown) and CA46-NCL-KNC (CA46-NCL-knockdown negative control) were established by lentivirus vector mediated transfection in Burkitt lymphoma cell line CA46. The half maximal inhibitory concentration (IC₅₀) of CA46-NCL-KD, CA46-NCL-KNC, and CA46 to adriamycin were detected by cell proliferation assay (MTS). The expression of NCL mRNA and protein in CA46-NCL-KD and CA46-NCL-KNC cells were dectected by Q-PCR and Western blot, respectively. The cell cycle of CA46-NCL-KD, CA46-NCL-KNC, and CA46 cells were detected by flow cytometry. The expression of TK1 protein in CA46-NCL-KD and CA46-NCL-KNC cells was detected by an enhanced chemiluminescence (ECL) dot blot assay. RESULTS: The level of serum TK1 in the initial treatment group was 0.43(0-30-1.01) pmol/L, which was lower than 10.56(2.19-14.99) pmol/L in the relapsed/refractory group (P<0-01), and the relative expression level of NCL protein in peripheral blood was also significantly lower. The IC₅₀ of CA46-C23-KD cells to adriamycin was (0.147±0.02) μg/ml, which was significantly lower than (0.301±0.04) μg/ml of CA46-C23-KNC cells and (0.338±0.05) μg/ml of CA46 cells (P<0.05). Compared with CA46-NCL-KNC cells, the expression of NCL mRNA and protein, TK1 protein decreased in CA46-NCL-KD cells, and the proportion of S phase and G₂/M phase also decreased, while G0/G1 phase increased in cell cycle. CONCLUSION The increased expression of NCL in DLBCL and CA46 cells indicates low sensitivity to drug. NCL may participate in regulation of lymphoma proliferation by affecting TK1 expression, thereby affecting the drug sensitivity.
Humans ; Leukocytes, Mononuclear/metabolism* ; Apoptosis ; Cell Line, Tumor ; Lymphoma ; Thymidine Kinase/pharmacology* ; Doxorubicin/pharmacology* ; Cell Division ; RNA, Messenger/genetics*

Targeted point mutagenesis through homologous recombination has been widely used in genetic studies and holds considerable promise for repairing disease-causing mutations in patients. However, problems such as mosaicism and low mutagenesis efficiency continue to pose challenges to clinical application of such approaches. Recently, a base editor (BE) system built on cytidine (C) deaminase and CRISPR/Cas9 technology was developed as an alternative method for targeted point mutagenesis in plant, yeast, and human cells. Base editors convert C in the deamination window to thymidine (T) efficiently, however, it remains unclear whether targeted base editing in mouse embryos is feasible. In this report, we generated a modified high-fidelity version of base editor 2 (HF2-BE2), and investigated its base editing efficacy in mouse embryos. We found that HF2-BE2 could convert C to T efficiently, with up to 100% biallelic mutation efficiency in mouse embryos. Unlike BE3, HF2-BE2 could convert C to T on both the target and non-target strand, expanding the editing scope of base editors. Surprisingly, we found HF2-BE2 could also deaminate C that was proximal to the gRNA-binding region. Taken together, our work demonstrates the feasibility of generating point mutations in mouse by base editing, and underscores the need to carefully optimize base editing systems in order to eliminate proximal-site deamination.
APOBEC-1 Deaminase ; genetics ; metabolism ; Animals ; Bacterial Proteins ; genetics ; metabolism ; Base Sequence ; CRISPR-Associated Protein 9 ; CRISPR-Cas Systems ; Cytidine ; genetics ; metabolism ; Embryo Transfer ; Embryo, Mammalian ; Endonucleases ; genetics ; metabolism ; Gene Editing ; methods ; HEK293 Cells ; High-Throughput Nucleotide Sequencing ; Humans ; Mice ; Mice, Inbred C57BL ; Microinjections ; Plasmids ; chemistry ; metabolism ; Point Mutation ; RNA, Guide ; genetics ; metabolism ; Thymidine ; genetics ; metabolism ; Zygote ; growth & development ; metabolism ; transplantation

OBJECTIVETo observe the efficacy and safety of chemotherapy regimens oxaliplatin combined with capecitabine (CAPOX) or oxaliplatin combined with tegafur, gimeracil and oteracil potassium capsules (S-1)(SOX), and to investigate the value of expression of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) proteins in tumor tissue for predicting the efficacy of CAPOX and SOX regimens in advanced gastric cancer patients.

METHODSA total of 107 newly-diagnosed, stage Ⅲc/Ⅳ gastric cancer patients (no surgical indication, ECOG performance scores 0-2 and expected survival time ≥3 months) were recruited with 101 patients evaluated. The patients were randomly divided into two groups. One was study group in which the patients received CAPOX regimen. The other was control group received SOX regimen. Each patient received four cycles, at least two cycles chemotherapy every three weeks and followed up until death or lost. Tumor biopsies were obtained by gastroscopy for immunohistochemical examination of the expression of TP and DPD proteins before chemotherapy. Response rate (ORR), overall survival (OS) and time to tumor progression (TTP) of the patients were assessed.

RESULTSThe objective response rate (ORR) of the study and control groups was 49.0% (5/51) vs. 46.0% (23/50), respectively (P>0.05). The overall survival (OS) was 357.36±24.69 days in the study group and 349.87±22.63 days in the control group, and the time-to-progression (TTP) was 216.75±19.32 days in the study group and 220.54±18.47 days in the control group (P>0.05 for both). Stratified analysis showed that the ORR of TP-positive patients in the study group was significantly higher than that in the control group (72.0 % vs. 41.7 %, P=0.032). There was no significant difference in ORR between the TP-negative patients in the study and control groups (26.9% vs. 50.0%, P=0.087), while the ORR of DPD-positive patients in the control group was significantly higher than that of the study group (51.9% vs. 34.6%, P=0.046). There was no significant difference in the ORR between DPD-negative patients in the study and control groups (64.0% vs. 39.1%, P=0.084). The follow-up showed that the OS (378.42±22.56 days) and TTP (271.77±24.92 days) in the TP-positive patients of the study group were significantly longer than those of the control group (OS: 326.57±19.84 days, and TTP: 229.13±22.68 days)( P<0.05). The OS was 371.25±23.97 days and TTP was 264.66±21.36 days in the DPD-positive patients of control group, significantly longer than those of the study group (OS: 334.73±21.47days, and TTP: 208.58±20.70 days) (P<0.05). But there was no significant difference in the OS and TTP between the TP- and DPD-negative patients in the two groups (P>0.05). In respect of adverse events, both the rates of hematological and non-hematological toxicities were low and similar between the two groups (P>0.05), and well-tolerated by the patients.

CONCLUSIONSBoth CAPOX and SOX regimens are effective chemotherapeutic protocols in treatment of patients with advanced gastric cancer. The expression levels of TP and DPD in tumor tissue can be used as a predictive factor for the efficacy of capecitabine or tegafur, gimeracil and oteracil potassium capsules combined with oxaliplatin regimens. CAPOX chemotherapy regimen is more suitable for the TP-positive gastric cancer patients, and SOX regimen is more suitable for the DPS-positive gastric cancer patients.

Antineoplastic Agents ; adverse effects ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; adverse effects ; therapeutic use ; Capecitabine ; administration & dosage ; adverse effects ; Capsules ; Dihydrouracil Dehydrogenase (NADP) ; metabolism ; Disease Progression ; Humans ; Neoplasm Proteins ; metabolism ; Organoplatinum Compounds ; administration & dosage ; adverse effects ; Oxonic Acid ; administration & dosage ; adverse effects ; Pyridines ; administration & dosage ; adverse effects ; Stomach Neoplasms ; drug therapy ; metabolism ; mortality ; pathology ; Tegafur ; administration & dosage ; adverse effects ; Thymidine Phosphorylase ; metabolism

Thymidine is a commercially useful precursor for production of antiviral compounds such as stavudine and azidothymidine. Biosynthesis of thymidine by Escherichia coli BL21 (DE3) was studied using metabolic engineering methods. The deoA, tdk and udp of the salvage pathway were disrupted from E. coli BL21 to construct BS03 that produced 21.6 mg thymidine per liter. Additional deletion of pgi and pyrL increased the supply of thymidine precursors and the resulting strain BS05 produced 90.5 mg thymidine/L. At last, ushA, thyA, dut, ndk, nrdA and nrdB of thymidine biosynthetic pathway were overexpressed, and the resulting strain BS08 produced 272 mg thymidine/L. In fed-batch fermentation, BS08 accumulated 1248.8 mg thymidine/L. Metabolically engineered strain E. coli has potential applications for thymidine production.
Biosynthetic Pathways ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Industrial Microbiology ; Metabolic Engineering ; Thymidine ; biosynthesis

OBJECTIVETo explore the changes of anticancer efficiency of 5'-deoxy-5-fluorouridine (5'-DFUR) and 5-fluorouracil (5-Fu) in colorectal cancer cell line HT29 and LS174T cells after transfection of thymidine phosphorylase (TP) cDNA with a lentiviral vector.

METHODSTP cDNA was transfected into human colorectal cancer cell lines HT29 and LS174T with the lentiviral vector pLenti6.3-MCS-IRES2-EGFP, and the transfection efficiency of the two cell lines passed 5 generations was analyzed by flow cytometry. The expression of TP protein and the relative quantitative expression of TP mRNA in these 2 cell lines were detected by Western blot and RT-PCR, respectively. The 50% inhibitory concentration (IC50) of 5'-DFUR and 5-Fu in both HT29 and LS174T parent cells and TP-transfected cells were assessed by MTS assay. Finally, the concentration of converted 5-Fu was detected by high performance liquid chromatography (HPLC) either in the medium containing a series of concentrations of 5'-DFUR, in which HT29/HT29-TP or LS174T/LS174T-TP cells were cultured, or in the cell culture lysates.

RESULTSThe HT29 and LS174T cells transfected with human TP cDNA were monitored for 5 generations, and their transfection efficiency was about 95.0%. Immunohistochemical staining showed that both the parent cells and TP-transfected HT29 and LS174T cells were TP-positive, while vector-transfected cells were TP-negative. Western blotting showed that the TP protein expression in HT29-TP and LS174T-TP cells were significantly increased compared with that in their parents cells. The relative quantity (RQ) values of TP mRNA in HT29-TP and LS174T-TP cells were 8.45 ± 0.15 and 2 615.02 ± 253.97, respectively, which were significantly higher than that in their parents cells (P < 0.01). The IC50 values of 5'-DFUR on HT29-TP cells and its parents cell were (14.33 ± 0.74) µmol/L and (707.66 ± 5.66) µmol/L, respectively (P < 0.05), while (0.59 ± 0.11) µmol/L in LS174T-TP cells and (239.20 ± 21.83) µmol/L in its parent cells, respectively (P < 0.05). The IC50 values of 5-Fu of HT29-TP cells and its parents cells were (5.42 ± 0.75) µmol/L and (14.19 ± 0.97) µmol/L, respectively (P < 0.05), while (4.41 ± 0.96)µmol/L in LS174T-TP cells and (16.42 ± 2.12)µmol/L in its parents cells, respectively (P < 0.05). The HPLC results showed that the 5-Fu concentration detected from media contained a series of concentrations of 5'-DFUR for culturing HT29-TP and LS174T-TP cells were 12.2 to 28.7-folds and 13.1 to 23.6-folds, respectively, higher than that in their parents cells, (P < 0.01 for all). Otherwise, just a little of 5-Fu was detected in the two TP-transfected cells lysate, about 0.9% to 4.2% of 5-Fu detected in the media of the same cultured cells, whereas no 5-Fu was detected in the two parent cell lysates.

CONCLUSIONSTransfection of TP cDNA into colorectal cancer cell lines HT29 and LS174T with lentiviral vector can improve the expression of both TP mRNA and TP protein levels in passaged cells, enhance the conversion of 5-Fu from 5'-DFUR in the medium, and result in an enhanced anticancer effect on these two cell lines.

Antineoplastic Agents ; pharmacology ; Cell Line ; Cell Line, Tumor ; Colorectal Neoplasms ; genetics ; metabolism ; DNA, Complementary ; Floxuridine ; pharmacology ; Fluorouracil ; Genetic Vectors ; HT29 Cells ; Humans ; RNA, Messenger ; Thymidine Phosphorylase ; genetics ; metabolism ; Transfection

Alveolar epithelial type II (AT II) cells are essential for lung development and remodeling, as they are precursors for type I cells and also produce other non-repair cells (fibroblasts). Progenitor cells are believed to possess capability of multi-potent transdifferentiation, which is closely related to the niche, suggesting the importance of establishment of a lung progenitor cell niche model. We hypothesized that pulmonary surfactant-associated protein A (SPA) suicide gene system would cause AT II cell to kill itself through apoptosis and leave its niche. In vitro, the recombinant adeno-associated virus vectors-SPA-thymidine kinase (rAAV-SPA-TK) system was established to get targeted apoptotic AT II cells. The apoptosis of AT II cells was detected by using MTT. The results showed that cloned SPA gene promoter had specific transcriptional activity in SPA high expression cells, and SPA high expression cells (H441) transfected with TK gene had higher sensitivity to ganciclovir (GCV) than SPA low expression cells (A549). In vivo, increased apoptosis of AT II cells induced by GCV in rAAV-SPA-TK system was observed by TUNEL. Finally, the successful packaging and application of rAAV-SPA-TK system provide experimental basis to get specific lung progenitor cell (AT II) niche in vitro and in vivo.
Antiviral Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cells, Cultured ; Dependovirus ; genetics ; Dose-Response Relationship, Drug ; Electrophoresis, Polyacrylamide Gel ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Ganciclovir ; pharmacology ; Gene Expression Regulation, Neoplastic ; Genes, Transgenic, Suicide ; genetics ; Genetic Vectors ; genetics ; Humans ; In Situ Nick-End Labeling ; Luciferases ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics ; Pulmonary Alveoli ; cytology ; metabolism ; Pulmonary Surfactant-Associated Protein A ; genetics ; metabolism ; Thymidine Kinase ; genetics ; metabolism

OBJECTIVETo study the killing effects of the liposome-mediated thymidine kinase (TK)/ganciclovir (GCV) system on MG-63 osteosarcoma (OS) cells and its bystander effects.

METHODSLiposome-mediated TK gene transfected into MG-63 OS cells, the efficiency of transfection was analyzed by flow cytometry and observed under inverted fluorescence microscope. Non-transfected osteosarcoma MG-63 cells were divided into three groups,in the experimental group 1 transfected TK/GCV cells cultured in solutiona liquid mixture by supernatant by 1/10,1/7,1/5,1/2 ratio to original broth; in the experimental group 2 transfected cells cultured in solutiona liquid mixture of supernatant filtered through 0.22 microm filter by 1/10,1/7, 1/5, 1/2 ratio to original broth, in control group the transfection cells cultured in original culture solution. Cell growth inhibition rate and osteosarcoma cell sensitivity to TK/GCV system were measured by MTT assay in each group.

RESULTSThe TK gene was transfected into MG-63 OS cells successfully by liposome-mediated, flow cytometry instrument detection TK gene transfection cell transfection efficiency can reach 75.5%. Six days later the MTT assay showed that in the experimental group 1 inhibition rate of all concentration ratio of the mixed culture fluid were statistically significant as compared with the control group (P < 0.05), and in the experimental group 2 that of the 1/10 and 1/7 of concentration ratio of mixed culture medium was not statistically significant as compared with the control group (P > 0.05). TK gene transfected MG-63 cells increased with the the GCV concentration,the cell apoptosis rate increased.

CONCLUSIONThe experiment demonstrated that the MG-63 OS cells are sensitive to the liposome-mediated TK/GCV system and bystander effects are significant.

Apoptosis ; drug effects ; Bone Neoplasms ; enzymology ; genetics ; physiopathology ; Bystander Effect ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Ganciclovir ; toxicity ; Humans ; Osteosarcoma ; enzymology ; genetics ; physiopathology ; Thymidine Kinase ; genetics ; metabolism ; toxicity

OBJECTIVESTo study the change of ability to transform from 5'-deoxy-fluorouracil monophosphate (5'-DFUR) to fluorouracil (5-FU) in human colon cancer cell lines SW480 and LOVO which transfected with thymidine phosphorylase (TP) gene. And to discuss the anti-cancer activity of 5'-DFUR to SW480 and LOVO cells.

METHODSTP cDNA were transfected into human colorectal cancer cell lines SW480 and LOVO with the lentiviral vector, pLenti6.3_MCS_IRES2-EGFP. The transfection efficiency was analyzed by flow cytometer, the mRNA expression of TP was detected by RT-PCR, and the TP protein expression was detected by Western blot, and the volumes of 5-FU converted from 5'-DFUR both in 2 cells and medium were detected by high performance liquid chromatography (HPLC). The 50% inhibitory concentration (IC50) of 5'-DFUR on these 2 colon cancer cell lines both wild type and TP-transfected cells were evaluated by MTT assay.

RESULTSThe colorectal cancer cell lines SW480 and LOVO transfected with human TP cDNA were monitored 5 generations, and the transfections efficiency rate wea about 95%. Compared with wild type cell SW480 and LOVO, the RQ values of mRNA expression of SW480-TP and LOVO-TP were (695 ± 171) folds (t = -7.00, P = 0.002) and (282 ± 87) folds (t = -5.61, P = 0.030), respectively. Also TP protein expression in SW480-TP and LOVO-TP were higher than their parent cells shown by Western blot. The volume of 5-FU converted from 5'-DFUR in the medium cultured SW480-TP and LOVO-TP were increased compared with their parent cells, respectively (t = 19.406-66.921, P < 0.01), whereas few of 5-FU was detected both in wild, and TP-transfected cells. After transfected with TP cDNA, the IC50 of 5'-DFUR on SW480-TP and LOVO-TP were (587 ± 17) µmol/L and (1088 ± 89) µmol/L respectively, and there were significantly less than their parent cells (t = -32.59 and -8.52, P < 0.01).

CONCLUSIONSThe stabilized transfections of SW480 and LOVO with higher TP expression could be built with lentiviral vector. Transfected TP cDNA into SW480 and LOVO, could improve the expression both of TP mRNA and TP protein, increase the volume of 5-FU converted from 5'-DFUR in medium, and result in an enhancement of anticancer effect on these 2 cells.

Cell Line, Tumor ; Colonic Neoplasms ; pathology ; Floxuridine ; metabolism ; Fluorouracil ; metabolism ; Humans ; Thymidine Phosphorylase ; genetics ; Transcription, Genetic ; Transfection

Telbivudine is an L-nucleoside analogue with potent antiviral activity against hepatitis B virus (HBV). Clinical trials have shown that telbivudine has a more potent and sustained antiviral activity with a lower frequency of viral resistance than lamivudine. Although there are several reports concerning the safety profile of telbivudine, most adverse events are described as mild and transient in nature. Here we report two cases of telbivudine-induced myopathy in patients with chronic hepatitis B who were siblings.
Adult ; Antiviral Agents/adverse effects/*therapeutic use ; Creatine Kinase/blood ; Electromyography ; Hepatitis B, Chronic/*drug therapy/metabolism/pathology ; Humans ; Male ; Muscle, Skeletal/pathology ; Muscular Diseases/etiology ; Siblings ; Thymidine/adverse effects/*analogs & derivatives/therapeutic use

OBJECTIVE: To investigate the differential expression of the sensitive and resistant relative proteins in human breast cancer tissue. METHODS: A drug sensitive group and a drug resistant group for chemotherapy in patients with breast cancer were selected through neoadjuvant. The differential protein expression in 2 groups was detected by proteomics techniques, and parts of differential proteins were identified by Western blot. RESULTS: There were 13 differential proteins in the 2 groups, in which the expression of 3 proteins was up-regulated and 10 down-regulated. Seven proteins were identified by Western blot. The expression of keratin type I cytoskeletal 19 (KIC19), thymidine phosphorylase (TYPH) was upregulated, and the expression of heat shock protein 27 (HSP27), keratin type I cytoskeletal 9 (KIC9), collagen alpha-2(VI) (CO6A2), vimentin (VIME), and actin cytoplasmic 1 (ACTB) was down-regulated in the drug resistant group. There was significant difference between the 2 groups (P<0.01). CONCLUSION The expression of KIC19 and TYPH may be correlated with drug resistance in patients with breast cancer, and HSP27, KIC9, CO6A2, VIME, and ACTB may be correlated with drug sensitivity.
Adult ; Aged ; Breast Neoplasms ; drug therapy ; genetics ; metabolism ; Carcinoma, Ductal, Breast ; drug therapy ; genetics ; metabolism ; Drug Resistance, Neoplasm ; genetics ; Female ; Gene Expression Profiling ; HSP27 Heat-Shock Proteins ; metabolism ; Humans ; Keratin-19 ; metabolism ; Keratin-9 ; metabolism ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Proteins ; metabolism ; Proteome ; metabolism ; Proteomics ; Thymidine Phosphorylase ; metabolism