OBJECTIVE: To investigate the protective effect of protein kinase C (PKC) inhibitor rottlerin on rat renal vascular endothelial injury induced by lipopolysaccharide (LPS). METHODS: Rat renal microvascular endothelial cells cultured for 3-6 generations were divided into three groups according to random number table: blank control group in which cells were not challenged, LPS group in which cells were only stimulated by LPS 10 mg/L for 24 hours, and PKC inhibitor group in which cells were treated with PKC inhibitor rottlerin 2 μmol/L 30 minutes before LPS stimulation. The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL-1β, IL-8) were determined by enzyme-linked immunosorbent assay (ELISA). Monolayer permeability was determined by Transwell assay. The expressions of PKC, RhoA and vascular endothelial-cadherin (VE-cadherin) were detected by Western Blot. The morphological characteristic and distribution of F-actin was measured by laser confocal fluorescence microscope. RESULTS: Compared with blank control group, the levels of inflammatory cytokines at 24 hours after 10 mg/L LPS stimulation were significantly increased in LPS group [TNF-α (ng/L): 397.3±25.4 vs. 46.8±8.9, IL-1β (ng/L): 76.7±11.2 vs. 12.6±3.2, IL-8 (ng/L): 574.5±31.4 vs. 73.2±9.6, all P < 0.05], the permeability of endothelial cells was significantly increased (A value: 1.32±0.03 vs. 0.36±0.02, P < 0.05), while the expressions of PKC and RhoA were significantly up-regulated (PKC/β-actin: 0.88±0.02 vs. 0.61±0.03, RhoA/β-actin: 0.96±0.01 vs. 0.49±0.03, both P < 0.05), VE-cadherin expression was significantly down-regulated (VE-cadherin/β-actin: 0.51±0.01 vs. 0.72±0.04, P < 0.05), and the F-actin distribution disorder had obvious stress fiber formation. Compared with LPS group, the levels of inflammatory cytokines were significantly lowered in PKC inhibitor group [TNF-α (ng/L): 127.4±14.6 vs. 397.3±25.4, IL-1β(ng/L): 43.2±7.8 vs. 76.7±11.2, IL-8 (ng/L): 212.7±18.2 vs. 574.5±31.4, all P < 0.05], the permeability of endothelial cells was significantly decreased (A value: 0.81±0.02 vs. 1.32±0.03, P < 0.05), the expressions of PKC and RhoA were significantly down-regulated (PKC/β-actin: 0.44±0.03 vs. 0.88±0.02, RhoA/β-actin: 0.63±0.05 vs. 0.96±0.01, both P < 0.05), the VE-cadherin expression was significantly up-regulated (VE-cadherin/β-actin: 0.69±0.03 vs. 0.51±0.01, P < 0.05), and the F-actin remodeling and stress fiber formation were significantly reduced. CONCLUSIONS PKC inhibitor could significantly attenuate the damage of vascular endothelial barrier induced by LPS, and plays an important role in endothelial cell barrier.
Acute Kidney Injury/prevention & control* ; Animals ; Endothelium, Vascular/drug effects* ; Interleukin-1beta ; Lipopolysaccharides/toxicity* ; Protein Kinase C/antagonists & inhibitors* ; Protein Kinase Inhibitors/pharmacology* ; Random Allocation ; Rats

AIMTo study the direct effect and kinetics of sodium quercetin-7,4'-disulphate (SQDS) on recombinant human protein kinase CK2 holoenzyme.

METHODSThe recombinant human CK2 holoenzyme activity was assayed by detecting incorporation of 32P of [gamma-32P] ATP into the substrate in various conditions.

RESULTSThe recombinant human CK2 was a second messenger (Ca2+, cAMP and cGMP) independent protein kinase. The characterization and function of the reconstituted holoenzyme were consistent with those of native CK2. SQDS was shown to strongly inhibit the holoenzyme activity of recombinant human protein kinase CK2 with an IC50 of 4.4 mumol.L-1, which was more effective than DRB and A3, known CK2 special inhibitors. Kinetic studies of SQDS on recombinant human CK2 showed: the inhibition was competitive with ATP and noncompetitive with casein.

CONCLUSIONSQDS is a potent inhibitor of protein kinase CK2. This study provide experimental basis for the development of more effective inhibitors of CK2 and for clinical application of SQDS in the future.

Casein Kinase II ; Dichlororibofuranosylbenzimidazole ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Humans ; Kinetics ; Protein-Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; Quercetin ; analogs & derivatives ; pharmacology ; Recombinant Proteins ; antagonists & inhibitors ; metabolism

Tyrosine kinase inhibitors (TKI) significantly reduce the risk of recurrence and metastasis and prolong survival in patients with gastrointestinal stromal tumors (GIST), but drug resistance is often inevitable. Immunotherapy has been proven effective in multiple solid tumors, but the efficacy in GIST is unclear. The efficacy of immunotherapy depends on the tumor microenvironment (TME). Tumor-infiltrating immune cells and immune checkpoints are important components of TME, which not only participate in the regulation of tumor immune response but are also the key target of immunotherapy. A comprehensive analysis of them can clarify the mechanism of tumor immune escape. This review found that there are abundant tumor-infiltrating immune cells in GIST, which play an important role in tumor immune surveillance and escape. Although early clinical studies have shown that patients with GIST have a good tolerance to immunotherapy, the curative effect is not satisfactory. Therefore, how to select the responders of immunotherapy and coordinate the relationship between immunotherapy and TKIs is the key issue to be explored. At the same time, the gradual deepening of basic research and large sample prospective clinical trials will certainly provide more strategies for the application of immunotherapy in GIST.
Humans ; Gastrointestinal Stromal Tumors/drug therapy* ; Prospective Studies ; Immunotherapy/methods* ; Tumor Microenvironment ; Protein Kinase Inhibitors/pharmacology*

This study was aimed to explore the effect of VX-680, an aurora inhibitor, on proliferation and apoptosis of K562, KCL22 cell lines and CD34⁺ cells from chronic myeloid leukemia (CML) patients in vitro. The proliferation of K562 and KCL22 cell was detected by CCK-8 method. Apoptosis of cells was detected by Annexin V-PI labeling and flow cytometry. The colony forming ability of bone marrow CD34⁺ cells derived from CML patients and donors was determined by the colony forming test. The results showed that the treatment of K562, KCL22 and CML CD34⁺ cells with VX-680 of 20-100 nmol/L for 3 days could obviously inhibit the cell proliferation in a concentration-dependent manner (P < 0.01). VX-680 treatment significantly induced apoptosis of K562 and KCL22 cells. Compared to bone marrow CD34⁺ cells derived from the healthy donors, the colony forming ability of CML CD34⁺ cells derived from bone marrow of CML patients was remarkably reduced (P < 0.01). It is concluded that VX-680, an aurora inhibitor, can inhibit the proliferation and induce apoptosis of CML cells in vitro.
Apoptosis ; drug effects ; Aurora Kinase A ; antagonists & inhibitors ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; pathology ; Piperazines ; pharmacology ; Protein Kinase Inhibitors ; pharmacology

Lung cancer is the most common in incidence and mortality worldwide. With the development of next generation sequencing (NGS) detection technology, more and more patients with rare anaplastic lymphoma kinase (ALK) fusion mutations were detected. A case of advanced lung adenocarcinoma with rare COX7A2L-ALK (C2:A20) fusion detected by NGS was reported in Peking Union Medical College Hospital, and all cases with rare ALK fusion mutations were searched from medical datebase from January 1, 2014 to March 31, 2021, to investigate the treatment of rare ALK fusion mutations with ALK inhibitors. The best response of the patient was assessed as partial response (PR) with Ceritinib treatment. By literature review, 22 cases of rare ALK fusion were reported in 19 articles. Combined with this case, 23 cases were analyzed. The objective response rate (ORR) was 82.6% (19/23) and disease control rate (DCR) was 95.7% (22/23) for rare ALK fusions patients treated with ALK inhibitors. Lung adenocarcinoma patients with rare ALK fusion could benefit from ALK inhibitors.
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Humans ; Anaplastic Lymphoma Kinase/genetics* ; Lung Neoplasms/diagnosis* ; Crizotinib ; Adenocarcinoma of Lung/genetics* ; Protein Kinase Inhibitors/pharmacology* ; Oncogene Proteins, Fusion/genetics*

Objective: To explore the effects and possible mechanisms of the novel pan-FGFR inhibitor BGJ398 on KG-1 cells in vitro. Methods: Effects of BGJ398 on cells proliferation were detected by CCK-8, the apoptosis was assessed by Annexin V-FITC. Reverse transcriptionquantitative polymerase chain reaction (q-PCR) analysis was used to detect the expression of apoptosis-related genes B cell lymphoma-2 (Bcl-2) and caspase-3. Western blotting analysis was performed to explore the proteins expression levels of Bcl-2, caspase-3 and the expression of p-AKT, p-S6K, p-ERK and FGFR1. Results: BGJ398 effectively inhibited cell proliferation by dose-dependent manners. BGJ398(1.4 µmol/L) induced apoptosis of KG-1 cells by 36.4%, compared with 4.5% in the control group(P<0.001). Treatment with BGJ398 at 1.4 µmol/L led to significant increases in the expression levels of caspase-3, and decreases in the expression of Bcl-2 (P<0.005). In accordance with these results, Western blot analysis further confirmed the increased expression of Bcl-2 protein along with elevated caspase-3 activity. In addition, BGJ398 markedly down-regulated FGFR1OP2-FGFR1 fusion protein, p-AKT and p-S6K expression, but not p-ERK expression. Conclusion: Novel pan-FGFR inhibitor BGJ398 substantially suppressed KG-1 cell growth and induced apoptosis by inhibiting the expression of FGFR1, p-AKT, p-S6K and regulating apoptosis-related proteins.
Apoptosis ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Phenylurea Compounds/pharmacology* ; Protein Kinase Inhibitors/pharmacology* ; Pyrimidines/pharmacology*

Amyloid beta-Peptides ; metabolism ; Animals ; ErbB Receptors ; antagonists & inhibitors ; Humans ; Memory Disorders ; prevention & control ; Protein Kinase Inhibitors ; pharmacology

Previous studies have demonstrated that rottlerin, a specific PKCdelta inhibitor, potentiates death receptor- mediated apoptosis through a cytochrome c-dependent or -independent pathway. However, its ability to regulate necrotic cell death, as well as the underlying mechanism, remains unknown. We found that in murine fibrosarcoma L929 cells, treatment with rottlerin protected the cells against TNF-induced necrosis, whereas it sensitized the cells to apoptosis induced by co-treatment with Hsp90 inhibitor geldanamycin and TNF, in a manner independent of its ability to inhibit PKC-delta. TNF treatment induced rapid accumulation of mitochondrial superoxide (O2") through the Nox1 NADPH oxidase when cells undergo necrosis. Moreover, pretreatment with rottlerin failed to induce the GTP-bound form of small GTPase Rac1 by TNF treatment, and subsequently suppressed mitochondrial O2(-) production and poly(ADP-ribose) polymerase activation, thus inhibiting necrotic cell death. Therefore, our study suggests that Nox1 NADPH oxidase is a new molecular target for anti-necrotic activity of rottlerin upon death-receptor ligation.
Acetophenones/*pharmacology ; Animals ; Benzopyrans/*pharmacology ; Cell Death/*drug effects ; Cell Line, Tumor ; Mice ; Protein Kinase Inhibitors/*pharmacology ; Superoxides/metabolism ; Tumor Necrosis Factor-alpha/*antagonists & inhibitors/pharmacology

Extracellular signal-regulated kinase 1/2 (ERK1/2) pathway has been shown to be important for regulating cell proliferation and survival. The role of ERK1/2 signaling in the survival and growth of neural stem cells (NSCs) has not been addressed adequately. In this work, we aimed to provide evidence that proliferation of NSCs in vitro is controlled via ERK1/2-dependent pathway. NSCs were isolated from embryonic day 14.5 (E14.5) cortex of mouse forebrain. Cells were harvested at the desired times (1 d, 3 d and 5 d) and the total protein was extracted and analyzed by Western blot. It was observed that ERK1/2 was activated during the proliferation of NSCs. In addition, mitogen-activated protein kinase kinase (MEK) inhibitor PD98059, which directly prohibited ERK1/2 phosphorylation, inhibited the formation of neurospheres, and this inhibitory effect was dose-dependent. After treatment with 20 mumol/L PD98059, the growth of NSCs was also inhibited with time-dependence. These data indicate that ERK1/2 is essential for the proliferation of NSCs derived from mouse embryonic cortex.
Animals ; Cell Proliferation ; Cerebral Cortex ; cytology ; embryology ; Flavonoids ; pharmacology ; Mice ; Mitogen-Activated Protein Kinase 3 ; physiology ; Neural Stem Cells ; cytology ; Phosphorylation ; Protein Kinase Inhibitors ; pharmacology

This study was aimed to investigate the therapeutic effect of two molecular targeted therapeutic drugs, tyrosine kinase inhibitors gefitinib and lapatinib, on JAK2 V617F positive myeloproliferative disorders (MPD). The human leukemia cell line (HEL cell line) carrying JAK2 V617F mutation was treated with gefitinib (0.5, 1, 5, 10, 25 µmol/L) and lapatinib (0.5, 1, 2, 4, 8, 16 µmol/L) respectively. MTT method was used to detect HEL cell proliferation. The apoptotic rate and cell cycle were measured by flow cytometry. The results showed that gefitinib could significantly inhibit the proliferation of HEL cells in a dose-dependent manner, it's correlation coefficients for 24 and 48 h were 0.991 and 0.895 respectively. IC(50) at 48 h was 5.4 µmol/L. Gefitinib could effectively induce apoptosis of HEL cells in a dose-dependent manner (r = 0.896). Otherwise, gefitinib could arrest HEL cells at G(0)/G(1) phase. The inhibitory effect of lapatinib was less than gefitinib, it's IC(50) of inhibiting proliferation of HEL cells was 19.6 µmol/L. It is concluded that both gefitinib and lapatinib can inhibit the proliferation of HEL cells. These two tyrosine kinase inhibitors can be used for researching of targeted therapy of JAK2 V617 positive MPD.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Myeloproliferative Disorders ; metabolism ; pathology ; Protein Kinase Inhibitors ; pharmacology ; Quinazolines ; pharmacology