Ferroptosis ; Piperazines/pharmacology* ; Cell Line, Tumor

OBJECTIVETo investigate the effect of tyrosine kinase inhibitor ZD6474 (Vandetanib) on the proliferative inhibition of K562 cells and its derived imatinib-resistant K562/G cells and its mechanism.

METHODSImatinib-resistant K562/G cells were obtained by culturing cells in gradually increasing concentrations of imatinib. The changed factors related to drug-resistance were tested by Western blot. ZD6474 and imatinib affected K562/G and parental K562 cells proliferation were analyzed by WST assay. Flow cytometry was used to analyze cell cycle. Direct inhibition of Src activity by ZD6474 was measured by a colorimetric ELISA assay with recombinant human Src kinase.

RESULTS10 µmol/L imatinib failed to inhibit K562/G cells proliferation or induce cell cycle arrest. Compared with that in parental K562 cells, there were marked high levels of p-Src and Src protein in K562/G cells. The expression of Bcl-2 and p-STAT3 also increased in K562/G cells. After 48 hours incubation, the IC(50) values of ZD6474 in K562 and K562/G cells were 1.61 µmol/L and 3.18 µmol/L, respectively. ZD6474 treatment caused accumulation of cells in the G(0)/G(1) fraction and cell apoptosis in K562 and K562/G cells. ZD6474 decreased the expression of p-Src and Src at post-transcriptional level. Moreover, ZD6474 increased the ratio of Bax/Bcl-2 and decreased the expression of p-STAT3 at the same concentration for inducing apoptosis.

CONCLUSIONSZD6474 is effective in inhibiting the proliferation of imatinib-resistant K562/G cells and parental K562 cells, and induces their apoptasis by significant inhibition of Src kinase activity. Our study provides a reliable experimental basis for chronic myeloid leukemia treatment with ZD6474.

Apoptosis ; drug effects ; Benzamides ; pharmacology ; Humans ; Imatinib Mesylate ; K562 Cells ; Piperazines ; pharmacology ; Pyrimidines ; pharmacology

OBJECTIVETo investigate the ultrasonographic indexes in the evaluation of complete penile erection after oral administration of sildenafil citrate in men with normal erectile function.

METHODSThe subjects lay supine, with the penis raised upwards, its back clinging to the abdomen. The probe was placed at the base of the ventral side of the penis for longitudinal and transverse section scanning. Observations were made on the corpus cavernosum, deep artery and deep dorsal vein of the penis at the time of flaccidity and complete erection after oral administration of sildenafil citrate, respectively.

RESULTSThe examinations were acceptable to all the subjects both physically and psychologically, and all were completed successfully with no complications. Compared with the flaccid state of the penis, obvious changes were observed in the state of complete erection, including marked increases in the diameter of the corpus cavernosum ([18.57 +/- 2.50] mm, increased by [106.8 +/- 62.1]%), the inside diameter of the deep artery ([1.18 +/- 0.26] mm, increased by [54.9 +/- 29.0]%), the peak systolic velocity ([32.5 +/- 10.7] cm/s, increased by [209.3 +/- 112.9]%), and the systolic acceleration ([5.71 +/- 2.71] cm/s2, increased by [179.3 +/- 138.2]%).

CONCLUSIONOral administration of sildenafil citrate followed by ultrasonography is a new approach to the objective evaluation of penile erection, characterized by convenience, safety, non-invasiveness, non-complication, easy acceptability and easy clinical application.

Adult ; Humans ; Male ; Penile Erection ; drug effects ; physiology ; Penis ; diagnostic imaging ; Piperazines ; pharmacology ; Purines ; pharmacology ; Sildenafil Citrate ; Sulfones ; pharmacology ; Ultrasonography

Abivertinib, a third-generation tyrosine kinase inhibitor, is originally designed to target epidermal growth factor receptor (EGFR)-activating mutations. Previous studies have shown that abivertinib has promising antitumor activity and a well-tolerated safety profile in patients with non-small-cell lung cancer. However, abivertinib also exhibited high inhibitory activity against Bruton's tyrosine kinase and Janus kinase 3. Given that these kinases play some roles in the progression of megakaryopoiesis, we speculate that abivertinib can affect megakaryocyte (MK) differentiation and platelet biogenesis. We treated cord blood CD34⁺ hematopoietic stem cells, Meg-01 cells, and C57BL/6 mice with abivertinib and observed megakaryopoiesis to determine the biological effect of abivertinib on MK differentiation and platelet biogenesis. Our in vitro results showed that abivertinib impaired the CFU-MK formation, proliferation of CD34⁺ HSC-derived MK progenitor cells, and differentiation and functions of MKs and inhibited Meg-01-derived MK differentiation. These results suggested that megakaryopoiesis was inhibited by abivertinib. We also demonstrated in vivo that abivertinib decreased the number of MKs in bone marrow and platelet counts in mice, which suggested that thrombopoiesis was also inhibited. Thus, these preclinical data collectively suggested that abivertinib could inhibit MK differentiation and platelet biogenesis and might be an agent for thrombocythemia.
Acrylamides/pharmacology* ; Animals ; Blood Platelets/drug effects* ; Cell Differentiation ; Megakaryocytes/drug effects* ; Mice ; Mice, Inbred C57BL ; Piperazines/pharmacology* ; Pyrimidines/pharmacology*

The remarkable therapeutic success of PDE5 inhibitors in the treatment of male erectile dysfunction has focused the attention of the researchers on better defining the properties of the individual inhibitors and PDE5 that contribute to the high affinity of these inhibitors for interaction with the PDE5 catalytic site. Recent molecular studies have demonstrated that vardenafil has high affinity for PDE5 and low dissociation rate from PDE5, which serves to explain why vardenafil works with low dosage, onsets quickly and has curative action in clinical practice. Moreover, the potency of vardenafil depends on its ring structure that resembles the purine moiety in cGMP.
Drug Interactions ; Erectile Dysfunction ; drug therapy ; Humans ; Imidazoles ; chemistry ; pharmacology ; Male ; Molecular Structure ; Phosphodiesterase Inhibitors ; chemistry ; pharmacology ; Piperazines ; chemistry ; pharmacology ; Sulfones ; chemistry ; pharmacology ; Triazines ; chemistry ; pharmacology ; Vardenafil Dihydrochloride

OBJECTIVE: To investigate the effect of palbociclib on cell cycle progression and proliferation of human renal tubular epithelial cells. METHODS: Human renal tubular epithelial cell line HK-2 was treated with 1, 5, 10, and 20 μmol/L of palbociclib, and the changes in cell proliferation and viability were examined by cell counting and CCK8 assay. EDU staining was used to assess the proliferation of HK-2 cells following palbiciclib treatment at different concentrations for 5 days. The effect of palbociclib on cell cycle distribution of HK-2 cells was evaluated using flow cytometry. SA-β-Gal staining and C12FDG senescence staining were used to detect senescence phenotypes of HK-2 cells after palbociclib treatment at different concentrations for 5 days. The relative mRNA expression levels of P16, P21, and P53 and the genes associated with senescence-related secretion phenotypes were detected by RT-PCR, and the protein expressions of P16, P21 and P53 were detected by Western blotting. RESULTS: Palbociclib inhibited HK-2 cell proliferation and induced cell cycle arrest in G1 phase. Compared with the control cells, HK-2 cells treated with high-dose (10 μmol/L) palbociclib exhibited significantly suppressed cell proliferation activity, and the inhibitory effect was the most obvious on day 5 ( CONCLUSIONS Palbociclib induces HK-2 cell senescence by causing cell growth arrest and delaying cell cycle progression.
Cell Cycle ; Cell Cycle Checkpoints ; Cellular Senescence ; Epithelial Cells ; Humans ; Piperazines/pharmacology* ; Pyridines/pharmacology* ; Tumor Suppressor Protein p53/genetics*

OBJECTIVETo evaluate the efficacy of sildenafil on nocturnal penile tumescence (NPT).

METHODSThirty-five patients with erectile dysfunction (ED), 28 cases of organic ED and 7 cases of psychogenic ED, were treated with sildenafil 100 mg before bedtime. The NPT of the patients was observed by using NEVA.

RESULTSErectile function significantly improved in the 28 cases of organic ED (P < 0.05), but not in the 7 cases of psychogenic ED (P > 0.05).

CONCLUSIONSildenafil can improve NPT of organic ED patients without sexual stimulation.

Adult ; Erectile Dysfunction ; drug therapy ; physiopathology ; Humans ; Male ; Middle Aged ; Penile Erection ; drug effects ; Phosphodiesterase Inhibitors ; pharmacology ; Piperazines ; pharmacology ; Purines ; pharmacology ; Sildenafil Citrate ; Sulfones ; pharmacology

The effects of monoterpene perilly alcohol (POH) alone or in combination with STI571 on the proliferation and apoptosis of the cell line K562 positive for Bcr/Abl were investigated. By using cell culture, the effect of the drugs on the proliferation of the cells was studied. TUNEL and flow cytometry assay of FITC-Annexin V and PI labeled cells were applied to detect the effects of the drugs on the apoptosis of the cells. The results showed that at 36 h, IC50 of POH on K562 positive for Bcr/Abl and HL-60 negative for Bcr/Abl were 81.0 +/- 11.3 micromol/L and 113.6 +/- 23.4 micromol/L respectively (P>0.05). POH could inhibit the proliferation of K562 in a time- and dose-dependent manner with the inhibitory rate of 100 micromol/L POH on K562 cells at 36 h being (53.2 +/- 3.65)%. K562 cells were more sensitive to STI571 than POH. IC50 of STI571 on K562 cells in 36 h was (0.256 +/- 0.054) micromol/L. In a time- and dose-dependent manner, POH induced the apoptosis of K562 cells with the percentage of apoptotic cells by 100 micromol/L POH at 40 h being (21.0 +/- 3.3)%. Both 100 micromo/L POH and 0.2 micromol/L STI571 had the same inhibitory effects on the K562 cells at 36 h. But at 12 and 24 h, the inhibitory rate of POH was significantly higher than that of STI571 (P<0.05) and the ability of STI571 inducing apoptosis at 36 h was greater than that of POH. 50 micromol/L, 100 micromol/L and 200 micromol/L POH in combination with 0.2 micromol/L STI571 could obviously increase the inhibitory effects on the cellular proliferation. Combined use of 50 micromol/L, 100 micromol/L, 200 micromol/L with 0.2 micromol/L STI571 could strongly induced apoptosis, especially 200 micromol/L POH in combination with 0.2 micromol/L STI571. It was concluded that the antileukemia effect of POH had no obvious Bcr/Abl positive selectivity. POH can inhibit the proliferation of K562 and induce the apoptosis in a time- and dose-dependent manner. K562 cells were more sensitive to STI571 than POH. POH in combination with STI571 could obviously enhance the abilities of STI571 inhibiting the proliferation and inducing apoptosis of K562 cells.
Antineoplastic Agents/*pharmacology ; Apoptosis/*drug effects ; Dose-Response Relationship, Drug ; Drug Synergism ; Fusion Proteins, bcr-abl/analysis ; HL-60 Cells ; K562 Cells ; Monoterpenes/*pharmacology ; Piperazines/pharmacology ; Pyrimidines/*pharmacology

STI571 is a new antileukemia agent targeting BCR-ABL tyrosine kinase and successfully used in treatment of leukemia patients. Despite strong efficacy of the tyrosine kinase inhibitor STI571, resistance has been observed in a significant proportion of leukemia patients. This review focuses on the diverse mechanisms of ST1571 resistance and its preventive measures.
Animals ; Antineoplastic Agents ; pharmacology ; Benzamides ; Drug Resistance, Neoplasm ; Humans ; Imatinib Mesylate ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; drug therapy ; Piperazines ; pharmacology ; Pyrimidines ; pharmacology

The present study was carried out to determine the role of 5-HT(1A) receptors in the generation and modulation of basic respiratory rhythm. Neonatal (aged 0-3 d) Sprague-Dawley rats of either sex were used. The medulla oblongata slice was prepared and the surgical procedure was performed in the modified Kreb's solution (MKS) with continuous carbogen (95% O2 and 5% CO2), and ended in 3 min. In cold MKS, a 600-700 microm single transverse slice was cut, which was rostral to the edge of area postrema and retained the hypoglossal nerve roots and some parts of the ventral respiratory group. The preparation was quickly transferred to a recording chamber and continuously perfused with carbogen-saturated MKS at a rate of 4-6 mL/min at 27-29 degrees C. Glass adsorb-electrodes containing Ag-AgCl needle were attached to the ventral roots of the hypoglossal nerve. Respiratory rhythmical discharge activity (RRDA) of the rootlets of hypoglossal nerve was recorded. Ten medulla oblongata slice preparations were divided into two groups. In group I, 5-HT(1A) receptor specific agonist (+/-)-8-hydroxy-2-(di-N-propylamino)tetralin hydrobromide (8-OHDPAT, 20 micromol/L) was added into the perfusion solution for 10 min first, after washing out, the 5-HT(1A) antagonist [4-iodo-N-[2-[4-methoxyphenyl]-1-piperazinyl]ethyl]-N-2-pyridynyl-benzamide hydrochloride] (PMPPI, 10 micromol/L) was applied to the perfusion solution for 10 min. In group II, after application of 8-OHDPAT for 10 min, additional PMPPI was added into the perfusion solution for 10 min. The discharges of the rootlets of hypoglossal nerve were recorded. Signals were amplified and band-pass filtered (100-3.3 kHz). Data were sampled (1-10 kHz) and stored in the computer via BL-420 biological signal processing system. Our results showed that 8-OHDPAT increased the respiratory cycle (RC) and expiratory time (TE) as well as reduced the integral amplitude (IA), but the changes of the inspiratory time (TI) were not statistically significant. PMPPI induced a significant decrease in RC, TE and TI, but the changes of IA were not statistically significant. The effect of 8-OHDPAT on the respiratory rhythm was partially reversed by additional application of PMPPI. Taken together with previous results, 5-HT(1A) receptors may play an important role in the modulation of RRDA in the medulla oblongata slice preparation of neonatal rats.
8-Hydroxy-2-(di-n-propylamino)tetralin ; pharmacology ; Animals ; Animals, Newborn ; Medulla Oblongata ; physiology ; Piperazines ; pharmacology ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptor, Serotonin, 5-HT1A ; physiology ; Respiration