To review recent studies on the research advance of RET( Rearranged during transfection) on-cogene in thyroid cancer,breast cancer,and lung cancer.The literatures on the structure of RET gene and coding product,cell signal transduction,relationship among thyroid cancer,breast cancer,and lung cancer are reviewed. RET gene encoding tyrosine kinase receptor,involving in cell signal transduction,rearrangement of RET gene is frequently seen in thyroid cancer,which is reported more and more in breast cancer,and lung cancer.Rearrange-ment of RET gene is closely correlated with the occurrence and progress of thyroid cancer,breast cancer,and lung cancer.Taking together,these findings suggest that RET present an attractive therapeutic target for the treatment of certain cancer subsets.

Objective To investigate the clinical characteristics and analyze prognostic risk factors of combined hepatocellular-cholangiocarcinoma. Methods The clinical data of 19 cases of combined hepatocellular-cholangiocarcinoma admitted in our hospital from January 1999 to December 2009 were analyzed retrospectively. The survival function was analyzed by Kaplan-Meier. The possible prognostic risk factors were tested by χ2-test. Results Hepatocellular-cholangiocarcinoma was diagnosed by pathology in the 19 patients, among which hepatic tunic was infiltrated in 13 cases, peritoneum involved in 1 case, intravascular cancer embolus in 1 case. At that time lymphocyte nodes metastasis in 2 cases were found by regional lymphadenectomy in 7cases. The 1-year and 3-year survival rates were 61% and 42%,respectively. Prognosis of patients with tumor size ＞ 5 cm ( χ2 = 4. 392, P = 0. 036 ), history of heavy drinking ( χ2 = 11.010, P = 0.001 ) or intraoperative blood transfusion ( χ2 = 4. 645,P = 0. 031 ) were worse than others. Conclusion It was difficult to get correct preoperative diagnosis of combined hepatocellularcholangiocarcinoma. Tumor size, history of heavy drinking and blood transfusion were all prognostic related risk factors.

To approach the method of isolation of tolerant human atrial myocytes, single myocytes were isolated by modified procedure of enzymatic dissociation with protease (type XXIV) and collagenase (type V). L-type calcium channel current (I(Ca-L)), sodium current (I(Na)), transient outward potassium current (I(to1)), and inward rectifier potassium current (I(K1)) in isolated atrial myocytes were recorded by using whole-cell patch-clamp techniques. Single cardiocytes isolated by this method were smooth, well-striated and rod-shaped. The yields of recordable myocytes, which viable and calcium-tolerant for electrophysiological studies, were 50%-60% of the total isolated cells. Compared with other isolation methods, this method was simple and steady, but with yield of a great number of qualified myocytes. The currents recorded in these cells were functional and active. Our research suggests that the myocytes isolated by the described method in this paper have normal electrophysiological function and are appropriate for patch-clamp experiments.
Cell Separation ; methods ; Humans ; Myocardium ; cytology ; Myocytes, Cardiac ; cytology ; Patch-Clamp Techniques

One of the main mechanisms of tumorigenesis and development is silencing of the patient's immune response to cancer-specific antigens.The defect of cancer immune surveillance may occur at any stage of tumor progression.In the tumor micro-environment,the abnormal expression of the immune checkpoint molecules that have an activation or inhibition effect on T lymphocytes can cause immune tolerance or escape of tumor cells.Targeted immune checkpoint molecules such as PD-1(programmed cell death protein 1)and its ligand PD-L1,have been shown to be new directions for the treatment of many types of cancer.microRNAs(miR-NAs)play an important role in tumor microenvironment.Studies have shown that miRNAs are highly expressed in some tumors and play an important role in immune response,especially in early regulation.Therefore,miRNAs may be ideal candidates for the regula-tion of immune checkpoints in cancer therapy.The abnormal expression of multiple miRNAs in cancer cells provides new opportunities for cancer therapy,but the exact function of these miRNAs and their interaction with immune checkpoints are still in the exploratory phase.This review summarizes the recent findings regarding the use of miRNAs as molecular regulators of immune checkpoints and their potential applications in the treatment of cancer in clinical practice.

D-myo-inositol 1,4,5-trisphosphate (IP(3)) plays an important role in signal transduction. It releases Ca(2+) from intracellular sites, which activates the Ca(2+)-dependent channels such as large-conductance Ca(2+)-activated potassium channels (BK channels). The present study was therefore designed to determine if the activity of BK channels in porcine coronary artery smooth muscle cells was increased by IP(3). Using the inside-out patch-clamp technique, the activity of single BK channels was recorded in porcine coronary artery smooth muscle cells. In excised inside-out membrane patches, IP(3) (10-50 micromol/L) enhanced the open probability (Po) of BK channels in a dose-dependent manner in the intracellular side of inside-out patches and its effect was almost completely abolished by washout. The open-state probability of the BK channels increased from a control level of 0.0402+/-0.0152 to 0.1365+/-0.0212 (20 micromol/L IP(3)) and 0.1865+/-0.0175 (30 micromol/L IP(3)). IP(3) decreased the mean close time markedly, but had no effect on the amplitude of BK channels. The activation of IP(3) on BK channels did not decline. The metabolite of IP(3) had no obvious effect on BK channels. This study provides evidence that IP(3) activates BK channels in porcine coronary artery smooth muscle cells in a dose-dependence manner.
Animals ; Coronary Vessels ; cytology ; metabolism ; Inositol 1,4,5-Trisphosphate ; physiology ; Large-Conductance Calcium-Activated Potassium Channels ; metabolism ; Muscle, Smooth, Vascular ; metabolism ; Swine ; Vasodilation ; physiology

OBJECTIVETo evaluate the efficacy of mitoxantrone combined high dose of cytarabine and recombinant human granulocyte colony-stimulating factor (MAG) regimen for mobilizing autologous peripheral blood stem cells (APBSC) in patients with hematopoietic malignancies.

METHODSFrom December 1995 to April 2003, 14 lymphoma and 29 acute leukemia patients were treated with high-dose cytarabine (2 g/m2 every 12 h, days 1 and 2) and mitoxantrone (10 mg/m2, days 2 and 3), followed by 300 microgram recombinant human granulocyte colony-stimulating factor per day (rhG-CSF 300 microg/d) i.e, the MAG regimen as mobilization regimen of peripheral blood stem cells. rhG-CSF was given subcutaneously when the white blood cell (WBC) count below 1.0 x 10(9)/L following the MA chemotherapy, APBSC were harvested when WBC count increased using Baxter CS3000plus or Cobe Spectra.

RESULTSMobilization was successful in 13 of 14 lymphoma patients with MNC (3.91 +/- 2.70) x 10(8)/kg, CD34+ cells (17.79 +/- 12.90) x 10(6)/kg. Meanwhile, mobilization was successful in 24 of 29 acute leukemia patients with average of 2.13 times for apheresis. The median MNC and CD34+ cells yielded were 3.62 x 10(8)/kg and 7.37 x 10(6)/kg respectively, rhG-CSF was used for a median time of 7 days. Excepting for grade I-II gastrointestinal toxicity in 8 and infection in 14 cases, no major side effects were observed. There was no mobilization-related mortality. Minimal residual diseases became undetectable after mobilization in some patients.

CONCLUSIONMAG is a safe and highly effective mobilization regimen in patients with lymphoma and acute leukemia.

Adolescent ; Adult ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cytarabine ; administration & dosage ; Female ; Granulocyte Colony-Stimulating Factor ; administration & dosage ; Hematopoietic Stem Cell Mobilization ; methods ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; drug effects ; Humans ; Lymphoma ; therapy ; Male ; Middle Aged ; Mitoxantrone ; administration & dosage ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; therapy ; Recombinant Proteins

The aim of the present study was to examine the effects of tetramethylpyrazine (TMP) on large-conductance Ca(2+)-activated potassium channels (BK(Ca) channels) in porcine coronary artery smooth muscle cells, in order to provide the experimental evidence for expounding the mechanism of TMP in dilating coronary artery. Cell-attached and inside-out single channel recording techniques were used to observe the effects of TMP on BK(Ca) channels as well as the effects after the cells were treated by protein kinase A (PKA) inhibitor or protein kinase G (PKG) inhibitor. In inside-out patch, TMP activated BK(Ca) channels by increasing open-state probability (N(Po)) and decreasing close time (Tc) in a concentration-dependent manner. TMP (0.73~8.07 mmol/L) in the bath solution increased N(Po) from (0.01+/-0.003) to (0.03+/-0.01)~(1.21+/-0.18) (P<0.01, n=10), and decreased Tc from (732.33+/-90.67) ms to (359.67+/-41.30) ~ (2.96+/-0.52) ms (P<0.01, n=10). These actions of TMP occurred even when the free Ca(2+) concentration in the bath was reduced to ~ 0 mmol/L. The specific inhibitors of PKA (H-89, 3 mumol/L) and PKG (KT-5823, 1 mumol/L) had no influence on the activation of TMP on BK(Ca) channels. These findings suggest that TMP can directly activate BK(Ca) channels in coronary artery smooth muscle, which probably is an important mechanism in dilating coronary artery.
Animals ; Coronary Vessels ; cytology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; drug effects ; physiology ; Pyrazines ; pharmacology ; Swine ; Vasodilator Agents ; pharmacology

OBJECTIVETo compare the changes of both inward rectifying K(+) (Kir) current(I(k1)) density and mRNA expression level of Kir2.1, a major subfamily of Kir in chronic human atrial fibrillation (CAF) with those in normal sinus rhythm (NSR).

METHODSI(k1) density was measured with whole-cell patch clamp technique in single myocyte isolated by an enzymatic dissociation method from right atrial appendages in patients with CAF (n = 8) and those with NSR (n = 12). The mRNA expression levels of Kir2.1 was determined in right atrial appendages from CAF (n = 19) and NSR (n = 18) by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR).

RESULTThe average resting membrane potentials were similar between CAF and NSR (-78.95 mV +/- 4.67 mV and -70.22 mV +/- 11.08 mV, P>0.05). I(k1) density in single myocyte significantly increased at hyperpolarized potential level (-100 mV) in CAF compared to that in NSR (-9.59 pA/pF +/- 2.47 pA/pF vs. -5.58 pA/pF +/- 2.52 pA/pF, P<0.01). The mRNA level of Kir2.1 was also significantly higher in CAF than that of NSR (0.50+/-0.16 vs. 0.34+/-0.09, P<0.05).

CONCLUSIONThe data suggest that Kir2.1 up-regulation and I(k1) current increase might contribute to the electrical remodeling in CAF patients.

Atrial Fibrillation ; genetics ; metabolism ; physiopathology ; Gene Expression ; Humans ; Myocytes, Cardiac ; metabolism ; physiology ; Patch-Clamp Techniques ; Potassium Channels, Inwardly Rectifying ; genetics ; metabolism ; RNA, Messenger ; genetics

Spontaneous transient outward currents (STOCs) play an important role in the myogenic regulation of small artery tone, such as coronary artery. In the present study, we investigated the electrophysiological properties and the regulation of STOCs in vascular smooth muscle cells (VSMCs) of porcine coronary artery by perforated patch-clamp technique. Our data showed that STOCs were dependent on voltage and extracellular calcium and they were highly variable in amplitudes and frequencies. STOCs superimposed stochastically onto whole-cell K(+) currents induced by step and ramp protocols. STOCs were completely abolished by ChTX [inhibitor of large-conductance Ca(2+)-activated potassium (BK(Ca)) channels], removal of extracellular Ca(2+), or addition of ryanodine (50 mumol/L) respectively. In contrast, CdCl2 and verapamil, inhibitors of voltage-dependent L-type Ca(2+) channels, had little effect on STOCs. Caffeine (5 mmol/L) transiently increased STOCs (hump), followed by a temporary inhibition. Ca(2+) ionophore A23187 increased both amplitude and frequency of STOCs. Na(+) ionophore monensin increased the frequency of STOCs. STOCs were strongly inhibited by KB-R7943, a selective inhibitor of the reverse mode of the Na(+)/Ca(2+) exchanger. Based on these observations, we conclude that STOCs are mediated by BK(Ca) channels. The generation and activation of STOCs depend upon Ca(2+) influx through Na(+)/Ca(2+) exchange and release of Ca(2+) from sarcoplasmic reticulum (SR) via ryanodine receptors. This suggests that Na(+)/Ca(2+) exchange determines calcium store refilling. Recycling of entering Ca(2+) from superficial SR may locally elevate Ca(2+) concentration at the plasma membrane, thereby activating BK(Ca) channels and then initiating STOCs.
Animals ; Coronary Vessels ; cytology ; physiology ; Electrophysiological Phenomena ; physiology ; Muscle, Smooth, Vascular ; cytology ; physiology ; Myocytes, Smooth Muscle ; cytology ; physiology ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; physiology ; Sodium-Calcium Exchanger ; physiology ; Swine

OBJECTIVETo compare the amplitude of the SK2 current (small conductance calcium-activated potassium channel) in human atrial myocytes with or without persistent atrial fibrillation (AF).

METHODSRight atrial appendage was obtained from 15 patients with sinus rate (SR) and 7 patients with AF underwent surgical valve replacement. Single myocyte was isolated by enzymatic dissociation method and the SK2 channel current density was recorded using whole-cell patch clamp techniques to detect the changes. Immunofluorescence was used to observe SK2 channel protein distribution on right atrial appendage.

RESULTSUsing the whole cell patch-clamp recording techniques, an inward rectifier K(+) mix currents could be obtained from both SR (n = 15) and AF (n = 7) samples, I(K1) mix currents density in single myocyte of AF group was significantly increased than in SR group [(-16.42 ± 5.32) pA/pF vs (-6.59 ± 2.24) pA/pF, P < 0.01], which could be partially inhibited by apamin (100 nmol/L). The apamin-sensitive current was obtained by subtraction of the currents before and after treatment with apamin. SK2 current density was significantly increased in AF group than that of SR group [(-9.81 ± 2.54) pA/pF vs (-3.67 ± 0.37) pA/pF, P < 0.01]. SK2 channel protein was evidenced with immunofluorescence method in right atrial appendage from AF group and SR group.

CONCLUSIONSK2 channel protein and current were present in atrial myocytes. The SK2 current density was significantly increased in AF group than in SR group suggesting that the increase of SK2 current might contribute to the electrical remodeling in AF patients.

Apamin ; pharmacology ; Atrial Fibrillation ; metabolism ; Cells, Cultured ; Female ; Humans ; Male ; Myocytes, Cardiac ; metabolism ; Patch-Clamp Techniques ; Small-Conductance Calcium-Activated Potassium Channels ; drug effects ; metabolism