OBJECTIVE: To investigate the mechanism of the in vitro toxicity of doxycycline to myeloma cell line H929 and also the possible pathway involved its toxicity. METHODS: Myeloma cell line H929 was treated with DOX, MEK inhibitor U0126 or RAS agonist ML-098, either alone or in combination. Then, the expression of p-MEK, caspase-3, caspase-9 and c-Jun in H929 were used to detected by Western blot; the cells proliferation and apoptosis were detected by CCK-8 assay and flow cytometry, respectively. RESULTS: DOX significantly increased the levels of cleaved caspase-3 and caspase-9, and down-regulated the level of p-MEK in H929 (P<0.05). MEK antagonist U0126 significantly increased the levels of cleaved caspase-3 and caspase-9, and down-regulated the level of p-MEK (P<0.05). After Dox combined with ML-098 treatment of H929 cells, the apoptosis rate of H929 cells was lower than that of DOX alone treatment group(P<0.05). Compared with DOX alone treatment group, the expressions of p-MEK and p-ERK1/2 in DOX+ML-098 combined treatment group were increased, and the levels of cleaved caspase-3,9 in H929 cells were decreased (P<0.05). The levels of c-Jun mRNA and protein increased in H929 when treated by DOX alone (P<0.05). CONCLUSION DOX can induce apoptosis of H929 via intrinsic apoptosis pathway, and MEK/ERK pathway and c-Jun possibly play a role in this process.
Apoptosis ; Caspase 3 ; Caspase 9/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; Doxycycline/pharmacology* ; Humans ; Mitogen-Activated Protein Kinase Kinases/pharmacology* ; Multiple Myeloma

OBJECTIVE: To investigate the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in multiple myeloma (MM) patients, and analyze the effect of doxycycline (DOX) on the expression of MMP-2 and MMP-9 in MM cells. METHODS: The peripheral blood and bone marrow samples of MM patients were collected, and the patients were divided into three groups: newly diagnosed group, remission group and relapsed/refractory group, while the peripheral blood samples of 34 health people and the bone marrow samples of 17 IDA patients were selected as normal control and control group. The levels of MMP-2 and MMP-9 were detected by ELISA. The protein levels of MMP-2 and MMP-9 in H929 cells treated by different concentrations of DOX were analyzed by Western blot. After H929 cells was treated by Akt inhibitor MK-2206 2HCl in combination with DOX, Western blot was used to detect the levels of MMP-2 and MMP-9. RESULTS: The levels of MMP-2 and MMP-9 in newly diagnosed MM patients were higher than those in control (P<0.05), while for the patients in the remission group were decreased, but still higher than those in control. The levels of MMP-2 and MMP-9 were increased again for the patients in relapsed/refractory group, and showed no significant difference as compared with those in newly diagnosed group. The levels of MMP-2 and MMP-9 could be inhibited by 10 mg/L and 15 mg/L DOX treated by H929 cell. The protein levels of MMP-2 and MMP-9 showed no altered in H929 cells treated by 5 nmol/L MK-2206 2HCl alone. DOX exerted more profound inhibitory effect to MMP-2 and MMP-9 expression in H929 cells when Akt inhibitor MK-2206 2HCl was combined with DOX. CONCLUSION The levels of MMP-2 and MMP-9 are increased in MM patients and related to the disease status of MM. DOX can inhibit the expression of MMP-2 and MMP-9 in MM cells, and antagonizing its activation of Akt signaling pathway can further enhance the inhibitory effect.
Doxycycline/pharmacology* ; Humans ; Matrix Metalloproteinase 2/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Multiple Myeloma/metabolism* ; Proto-Oncogene Proteins c-akt

Human pluripotent stem cells (hPSCs) are an important system to study early human development, model human diseases, and develop cell replacement therapies. However, genetic manipulation of hPSCs is challenging and a method to simultaneously activate multiple genomic sites in a controllable manner is sorely needed. Here, we constructed a CRISPR-ON system to efficiently upregulate endogenous genes in hPSCs. A doxycycline (Dox) inducible dCas9-VP64-p65-Rta (dCas9-VPR) transcription activator and a reverse Tet transactivator (rtTA) expression cassette were knocked into the two alleles of the AAVS1 locus to generate an iVPR hESC line. We showed that the dCas9-VPR level could be precisely and reversibly controlled by the addition and withdrawal of Dox. Upon transfection of multiplexed gRNA plasmid targeting the NANOG promoter and Dox induction, we were able to control NANOG gene expression from its endogenous locus. Interestingly, an elevated NANOG level promoted naïve pluripotent gene expression, enhanced cell survival and clonogenicity, and enabled hESCs to integrate with the inner cell mass (ICM) of mouse blastocysts in vitro. Thus, iVPR cells provide a convenient platform for gene function studies as well as high-throughput screens in hPSCs.
Animals ; Cell Line ; Clustered Regularly Interspaced Short Palindromic Repeats ; Doxycycline ; pharmacology ; Gene Expression Regulation ; drug effects ; Human Embryonic Stem Cells ; metabolism ; Humans ; Mice ; Nanog Homeobox Protein ; biosynthesis ; genetics ; Pluripotent Stem Cells ; metabolism

Animals ; CHO Cells ; Cricetulus ; Doxycycline ; pharmacology ; Immunohistochemistry ; Ki-67 Antigen ; genetics ; metabolism ; Plasmids ; Quality Control ; Staining and Labeling ; methods ; Transfection

BACKGROUND AND OBJECTIVEiASPP, an inhibitory member of the apoptosis-stimulating proteins of p53 (ASPP) family, has been found to be up-regulated in various human tumor types. This study was to construct an efficient doxycycline-regulated, lentiviral vector-mediated knockdown system for iASPP that will allow for inducible down-regulation of iASPP gene expression and preliminary functional analysis.

METHODSA pair of complementary oligos with hairpin structures targeting the iASPP gene and a negative control were synthesized, then ligated with pLVTHM vector and sequenced. The fragment containing the shRNA cassette was cloned to pLVCT-tTR-KRAB plasmid. The recombinant vectors were co-transfected with viral packaging mix into 293T cells, and viral supernatant was harvested to determine the titer. After treatment with or without doxycycline, HepG2 cells infected with virus were harvested and the expression of iASPP was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Its effects on tumor growth were characterized using MTS assay, soft agar colony formation, and flow cytometry analysis.

RESULTSThe lentiviral vector expressing shRNA that targets to the oncogene iASPP was constructed successfully. HepG2 infected with the lentivirus expressing shRNA against iASPP inhibited the expression of iASPP in the presence of doxycycline, which resulted in the repression of tumor cell proliferation and anchorage-independent growth potential.

CONCLUSIONSThe lentiviral vector-mediated tet-on system demonstrates efficient and inducible knockdown of iASPP in hepatocellular carcinoma cells. iASPP gene may be involved in tumorigenesis and progression of human tumors.

Apoptosis ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Proliferation ; Down-Regulation ; Doxycycline ; pharmacology ; Genetic Vectors ; Hep G2 Cells ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Lentivirus ; genetics ; Liver Neoplasms ; genetics ; metabolism ; pathology ; Plasmids ; RNA Interference ; RNA, Small Interfering ; genetics ; Recombinant Proteins ; genetics ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Transfection

OBJECTIVEBased on establishment of four rat models of experimental pulmonary hypertension (PH), the authors examined the inhibition of matrix metalloproteinases (MMPs) by doxycycline and its effect on the development of PH and associated pulmonary vascular remodeling.

METHODHealthy male Sprague-Dawley rats (weight 350 g to 400 g) were randomly divided into nine groups: Normal control group (N), four model groups (H, M, P, PM) and their corresponding drug intervention groups (HD, MD, PD, PMD) in which doxycycline was given by gavage at a 20 mg/kg daily dosage. On day 28 (day 35 for PM and PMD models), the animals were catheterized to record mean pulmonary arterial pressure (mPAP) and then sacrificed. Fulton Index [RV/(LV + S)] was measured immediately. Morphometric parameters, including percent vascular wall thickness and muscularization of non-muscularized peripheral pulmonary arterioles were determined microscopically. The activity of MMPs was measured by gelatin zymography in the lung tissue.

RESULTS(1) Rats in all model groups (H, M, P, PM) developed significant pulmonary arterial hypertension and right ventricular hypertrophy in comparison with their corresponding drug intervention groups (HD, MD, PD, PMD) and normal control group (N) (P < 0.01). For example, mPAP (mm Hg)(1 mm Hg = 0.133 kPa):N: 18.10 +/- 1.45, H: 27.20 +/- 1.55, HD: 23.90 +/- 2.13; Fulton Inedx(%):N: 23.41 +/- 1.84, H: 34.44 +/- 2.70, HD: 27.55 +/- 2.45. (2) The percent vascular wall thickness (WT%) and percentage of muscularization of non-muscular pulmonary arterioles were significantly increased in all model groups compared with drug intervention groups and normal group (P < 0.01). For example, WT%:N: 10.90 +/- 3.11, H:41.41 +/- 5.21, HD: 17.73 +/- 3.12; Muscularization(%):N: 13.83 +/- 3.72, H: 44.93 +/- 2.43, HD: 29.89 +/- 4.45. (3) The activity of MMPs was inhibited by doxycycline effectively as assessed by gelatin zymography (P < 0.01). For example, the activity of MMP2 (A x 10(3)):N: 1.43 +/- 0.24, H: 3.58 +/- 0.28, HD: 2.29 +/- 0.31.

CONCLUSIONDoxycycline attenuated PH and associated pulmonary vascular remodeling in all rat PH models. The study suggests that high expression and enhanced activity of MMPs may play a brutial role in the development of PH. Such phenomenon seems to be common in a variety of PH models of different etiology.

Animals ; Disease Models, Animal ; Doxycycline ; pharmacology ; Hypertension, Pulmonary ; metabolism ; physiopathology ; Male ; Matrix Metalloproteinases ; metabolism ; Pulmonary Artery ; metabolism ; Rats ; Rats, Sprague-Dawley

During the infection of host cells, IE2 protein is one of the first and most abundantly expressed products of HCMV genome, which plays an important role in the controlling of cell cycle and apoptosis. But the correlation between expression level and anti-apoptotic activity of IE2 protein is still not clear. In this study, we successfully established a HCMV IE2 protein expression cell line that was controlled by Tet-On system. The effect of IE2 protein on cell apoptosis and the expression of p53 was detected under different condition of induction. Our results showed that the IE2 protein could inhibit cell apoptosis induced by TNF-alpha. Additionally, the anti-apoptotic activity of IE2 protein seemed to be relevant to its expression level. However, we failed to detect any difference of p53 expression between the IE2 protein expression and non-expression cells. These data indicated that the IE2 protein might inhibit cell apoptosis through regulating different signal pathways.
Anti-Bacterial Agents ; pharmacology ; Apoptosis ; drug effects ; genetics ; Doxycycline ; pharmacology ; Gene Expression Regulation ; drug effects ; genetics ; HeLa Cells ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Plasmids ; genetics ; Trans-Activators ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo investigate the effects of endostatin and doxycycline on microcirculation patterns in melanoma and their molecular mechanisms.

METHODSTo establish mouse B16 melanoma model by subcutaneous injection of B16 melanoma cell suspension. The mice were divided into 3 experimental groups and 1 control group. To treat the mice in the 3 experimental groups with endostatin, doxycycline, endostatin and doxycycline, respectively, and the control group without any treatment. The tumor volume was measured and recorded to make comparison of their growth rate. To assess the expression of MMP-2, MMP-9 and TIMP-2 by immunohistochemical staining. The three microcirculation patterns of endothelium-dependent vessels, mosaic vessels and vasculogenic mimicry were counted. The activity of MMP-2, MMP-9 between different groups was examined by gelatin zymography.

RESULTSTumor growth in the three experimental groups was statistically significantly slower than that in the control group. The expression of MMP-2, MMP-9 and TIMP-2 in each treated group was significantly different with that in the control group. The amount of three microcirculation patterns in three experimental groups was less than that of the control group, and the amount of MV and VM in each experimental group was significantly less than that in the control group. By gelatin zymography, the enzyme activity of MMP-9, actived-MMP-2 and MMP-2/proMMP-2 in ES, DOX and ES + DOX group was lower than that in the control group, but the enzyme activity of pro-MMP-2 among the four groups was not significantly different.

CONCLUSIONThe combined use of doxycycline and endostatin in melanoma can inhibit the expression of MMPs, influencing the formation of different microcirculation patterns in melanoma.

Animals ; Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Doxycycline ; pharmacology ; Drug Combinations ; Drug Synergism ; Endostatins ; pharmacology ; Female ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Melanoma, Experimental ; blood supply ; enzymology ; pathology ; Mice ; Mice, Inbred C57BL ; Microcirculation ; drug effects ; Microvessels ; pathology ; Neoplasm Transplantation ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism ; Tumor Burden ; drug effects

OBJECTIVETo provide a sound cell source for further ex-vivo gene therapy for chronic pain, we attempt to develop an immortalized rat astrocyte cell line that expresses enkephalin regulated by doxycycline.

METHODSRetrovirus infection method was employed to develop an immortalized rat astrocyte cell line that could express enkephalin regulated by doxycycline. The hPPE gene expression level of immoralized astroyte cells (IAC)/ hPPE was detected by RT-PCR, indirect immunofluorescence staining and radioimmunoassay.

RESULTSIAC carrying Tet-on system transfected with preproenkephalin gene could secrete enkephalin that was regulated by doxycycline in a dose-dependent manner and hPPE gene activation could be repeated in on-off-on cycles through administration or removal of doxycycline.

CONCLUSIONAn immortalized rat astrocyte cell line that secrete enkephalin under the control of doxycycline is established successfully, which provides a research basis for transgenic cell transplantation for analgesia.

Animals ; Anti-Bacterial Agents ; pharmacology ; Astrocytes ; Cell Line, Transformed ; Chronic Disease ; Doxycycline ; pharmacology ; Enkephalins ; genetics ; metabolism ; Genetic Therapy ; methods ; Genetic Vectors ; Neurotransmitter Agents ; genetics ; metabolism ; Pain Management ; Protein Precursors ; genetics ; metabolism ; Rats ; Retroviridae ; genetics

OBJECTIVETo survey mycoplasma infection in female urogenital tract and analyze the drug sensitivity of mycoplasma in Changsha.

METHODSUreaplasma urealyticum (Uu) and Mycoplasma hominis (Mh) were detected in 6566 cases of female urogenital tract infection by means of mycoplasma culture and drug sensitivity reagent kit. Sensitivity tests for 10 antibiotics were also performed.

RESULTSA total of 2938 cases were mycoplasma-positive (positivity rate of 44.75%), including 2469 Uu-positive cases (37.6%), 52 Mh-positive cases (0.08%) and 417 cases positive for both Uu and Mh (6.35%). Josamycin, doxycycline, clarithromycin and azithromycin were more effective against Uu infection. Josamycin, doxycycline and thiamphenicol were more effective against Mh infection. Mixed infection with Uu and Mh was more resistant to most antibiotics but Josamycin and doxycycline.

CONCLUSIONThe female urogenital mycoplasma infection results mainly from Uu. Compared with simple Uu or Mh infection, mixed infection with Uu and Mh has significantly greater resistance to a wider variety of drugs. Josamycin and doxycycline are the primary choice for female urogenital mycoplasma infection in Changsha.

Adolescent ; Adult ; Aged ; China ; epidemiology ; Doxycycline ; pharmacology ; therapeutic use ; Drug Resistance, Bacterial ; Female ; Humans ; Josamycin ; pharmacology ; therapeutic use ; Microbial Sensitivity Tests ; Middle Aged ; Mycoplasma Infections ; drug therapy ; epidemiology ; microbiology ; Mycoplasma hominis ; drug effects ; Ureaplasma Infections ; drug therapy ; epidemiology ; microbiology ; Ureaplasma urealyticum ; drug effects ; Uterine Cervicitis ; microbiology