Expression of choline acetyltransferase in the rat barrel cortex by electrical stimulation / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe a turning performance in the rats excited by using a proper electrical stimuli of the barrel cortex region (BC), and the expression of choline acetyltransferase (ChAT) in the BC regions after electoral stimulation.</p><p><b>METHODS</b>SD rats were divided into three groups. The stimulation electrodes were surgically implanted into the bilateral BC regions in the control group and the experimental group rats. The experiment group post surgery for seven days was given the electrical impulses via connection with the electrodes for three times each day through consecutive three days. Three groups of the rats were killed and the brains were quickly removed for frozen sections and then performed with conventional HE and immunohistochemistry staining. And protein samples were prepared from brain and the hippocampus tissues of the three groups to detect the level of the ChAT protein by Western blot.</p><p><b>RESULTS</b>The experimental rats turn left or right when continuously stimulation in the bilateral BC regions with electric pulse. HE staining showed no significant damage around electrodes in the cerebral cortex. Compared with the control and blank groups, the ChAT positive rate in the brain section in the experimental rats was significantly high by immunohistochemistry assay; the level of the ChAT protein in the rats given the electrical stimulation increased.</p><p><b>CONCLUSION</b>Turnings performance of the rat could be initiated hy electrical stimuli in the BC region. Expression of ChAT is significantly higher in the BC regions of rat under electrical stimulation, suggesting that acetylcholine might be associated with signal transmission between senses and movement behavior in the nervous central system.</p>

Expression of nucleostemin mRNA and protein in the esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the mRNA and protein expression of nucleostemin (NS) in human esophageal squamous cell carcinoma.</p><p><b>METHODS</b>The mRNA and protein expression of NS were detected in 31 mucosal atypical hyperplasia specimens, 62 esophageal squamous cell carcinoma specimens and the matched normal esophageal mucosa samples by RT-PCR and immunohistochemistry method, respectively.</p><p><b>RESULTS</b>The positive expression rate of NS protein in normal esophageal mucosa, atypical hyperplasia and esophageal squamous cell carcinoma was 17.7% (11/62), 41.9% (13/31) and 69.4% (43/62), respectively. There was a significant difference among the above three groups (chi2 = 33.676, P < 0.01). The expression levels of NS mRNA in esophageal squamous cell carcinoma (0.971 +/- 0.121) was significantly higher than that in the atypical hyperplasia (0.913 +/- 0.085) and also in the normal esophageal mucosa (0.866 +/- 0.103; F = 14.829, P < 0.01). The expression level of both NS protein and mRNA was positively correlated with histological grade, infiltration depth, and lymph node metastasis (P < 0.05), but not with age, gender or pathological type (P > 0.05).</p><p><b>CONCLUSION</b>Our results indicate that nucleostemin mRNA and protein are over-expressed in human esophageal squamous cell carcinoma, and it may be related with its oncogenesis.</p>

Effect of hTERT ASODN on the oncogenicity and the inductive apoptosis of HL-60 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of hTERT antisense oligodeoxynucleotide (ASODN) on the oncogenicity and the inductive apoptosis of HL-60 cells.</p><p><b>METHODS</b>Apoptosis of HL-60 cells was detected by flow cytometry (FCM) and agarose gel electrophoresis. Both treated and untreated HL-60 cells were collected and transplanted into 5 BALB/c nude mice respectively, the formation of transplanted neoplasm and its morphologic change were observed. After the transplanted neoplasms were uniform with the ameliorated method in another 10 BALB/c nude mice, they were divided into 2 groups and injected ASODN and PBS into the neoplasm respectively. Seven days later, the tumor were measured, its morphology were observed, and the apoptotic cells were detected with a TUNEL kit.</p><p><b>RESULTS</b>After 72 h treatment there were DNA ladders and early apoptosis peak in hTERT ASODN treated HL-60 cells but was none in SODN treated and blank control cells. In tumor formation experiment, neoplasms were formed in ASODN treated group at 16-17 d and untreated group at 12-13 d. Neoplasm was formed in 2 of 5 ASODN treated mice and 4 of 5 untreated mice respectively. In untreated mice tumor tissues were rich in blood vasa and stromal tissue compared with that in ASODN treated mice. In tumor therapy experiment, before treatment, there was no difference in the average neoplasm physical volume between ASODN treated group [(100.9 +/- 24.6) mm3] and PBS treated group [(98.4 +/- 23.1) mm3] (P > 0.05). After treatment, the neoplasm volume in ASODN treated group [(422.7 +/- 326.4) mm3] was smaller than that in PBS treated group [(786.4 +/- 357.6) mm3] (P < 0.05). Histologically, there were many apoptosis cells in ASODN treated group, but was seldom seen in PBS treated group. The TUNEL positive cells in ASODN treated group were much more than that in PBS treated group (P < 0.05).</p><p><b>CONCLUSION</b>The hTERT ASODN induces apoptosis of HL-60 cells in vitro, reduces the tumor formation in BALB/c nude mice and inhibits the growth of the transplanted neoplasm.</p>

Screening effective sequences of small interfering RNAs targeting MDR1 gene in human gastric cancer SGC7901/VCR cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To screen effective sequences of small interfering RNA targeting MDR1 gene in human gastric cancer SGC7901/VCR cells.</p><p><b>METHODS</b>Four siRNAs (MDR1si326, MDR1si1513, MDR1si2631 and MDR1si3071) targeting MDR1 gene were designed and synthesized by in vitro transcription. The siRNA duplexes were used to transfect into the human gastric cancer SGC7901/VCR cells. The expression level of MDR1 mRNA and P-gp were detected by RT-PCR and Western blotting, respectively. The accumulation of intracellular adriamycin (ADR) was examined by flow cytometry and the cell sensitivity to ADR was demonstrated by MTT.</p><p><b>RESULTS</b>The SGC7901/VCR cells treated with 4 siRNAs led to reversal effect on multidrug resistance to different extents. Among the SGC7901/VCR cells treated by siRNAs for 48 h, the expression level of MDR1 mRNA in cells of MDR1si326 or MDR1si2631 group (0.42 +/- 0.07 or 0.49 +/- 0.02) was more decreased than that in cells of MDR1si1513 or MDR1si3071 group (P < 0.05). The accumulation of ADR in cells of MDR1si326 group was the most; in cells of MDR1si2631 group, more; in cells of MDR1si3071 group, lower and in cells of MDR1si1513 group, the lowest (P < 0.05). The relative reversal efficiency of cells of MDR1si2631 group to ADR was the highest and in cells of MDR1si326 group, higher (P < 0.05). There was no significant difference in the relative reversal efficiency between the cells of MDR1si1513 and MDR1si3071 groups (P > 0.05). The expression level of P-gp in cells of MDR1si326 group was the lowest among the SGC7901/VCR cells treated by siRNAs for 72 h.</p><p><b>CONCLUSION</b>The MDR1si326 with most, MDR1si2631 with more, MDR1si3071 with less and MDR1si1513 with least reversal effects on MDR1 gene mediated multidrug resistance were found in the human gastric cancer SGC7901/VCR cells.</p>

Abnormal expression of hMSH2 mRNA and mutation P53 protein in acute lymphoblastic leukemia / 中国实验血液学杂志

In order to investigate the mechanism of acute lymphoblastic leukemic cell malignant proliferation, the expressions of hMSH2 mRNA and mutation P53 (mtP53) protein in bone marrow cells of de novo acute lymphoblastic leukemia (ALL) were determined by in situ hybridization and immunocytochemical methods. The results showed the that percentage of positive cell with hMSH2 mRNA expression was (32.88 +/- 11.46)% in the de novo ALL group and (64.22 +/- 8.51)% in the control group. The percentage of positive cell with mtP53 protein expression was (29.25 +/- 9.45)% in the de novo ALL group, and (12.63 +/- 6.66)% in the control group. There was a significant negative correlation between the positive percentages of hMSH2 mRNA expression and mtP53 protein expression (r = -0.45, P < 0.05). It is concluded that defective MSH2 mRNA expression plays an important role in the pathogenesis of acute lymphoblastic leukemia, mtP53 protein mutation plays an important role in the development of acute lymphoblastic leukemia, the hMSH2 mRNA defect can lead to accumulation of the mutant P53 protein in acute lymphoblastic leukemia, and both jointly promote the pathogenesis of ALL.

Effects of c-myc antisense oligodeoxynucleotide on the telomerase activity and the induction of apoptosis in HL-60 cells / 中国实验血液学杂志

To investigate the effects of c-myc antisense oligodeoxynucleotide (ASODN) on the telomerase activity and the induction of apoptosis in HL-60 cells, and to explore the relationship between the telomerase activity and the expression of c-myc gene in HL-60 cells, after treatment by c-myc ASODN, the expression of c-myc was detected by RT-PCR, the apoptosis, cell cycle were detected with agarose gel electrophoresis and flow cytomety, and the telomerase activity was determined with TRAP-ELISA. The results showed that after blocking c-myc gene with ASODN for 72 hours, it is obvious that the expression of c-myc gene was inhibited. The percentage of S phase HL-60 cells decreased from 55.6% to 30%, the early apoptosis peak appeared (the percentage of apoptosis cells were 25.2%) and the DNA ladders were shown. OD(450 - 690) were 2.648 +/- 0.42, 2.324 +/- 0.36, 2.162 +/- 0.38, 1.952 +/- 0.14, 1.805 +/- 0.40, 1.616 +/- 0.41 and 2.466 +/- 0.29, respectively, as the cells were treated with 0, 1, 2, 3, 4, 5 micromol/L ASODN and 5 micromol/L SODN for 72 hours. The difference was significant when compared 3, 4, 5 micromol/L groups with 0 micromol/L ASODN group respectively (P < 0.05), but the difference was no significant when compared 1, 2 micromol/L ASODN and 5 micromol/L SODN groups with 0 micromol/L ASODN group (P > 0.05). It is concluded that the c-myc gene ASODN may induce the apoptosis of cells, inhibit cells from G(1) phase into S phase and regulate the telomerase activity down in HL-60 cells by blocking the expression of c-myc gene.

Detection of methylation of hMSH2 gene promoter region of esophageal cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To detect methylation in promoter region of hMSH2 gene in esophageal cancer.</p><p><b>METHODS</b>Specimens of cancer and normal tissues freshly removed from 32 cases of esophageal cancer patients without previous radiotherapy, chemotherapy or other treatment were preserved at -80 degrees C within 30 min. Methylation specific PCR (MSP) was used to detect methylation of mismatch repair gene (MMR) hMSH2 in promoter region in esophageal cancer and normal esophageal tissues.</p><p><b>RESULTS</b>The frequencies of methylation of hMSH2 gene in promoter region of cancer and normal esophageal tissues were 32.4% (11/32) and 0/30 (0%), respectively, and significant difference was found between the two groups (P < 0.01). The frequency of methylation in elder patients (> or = 70 years old) was significantly higher than that in younger patients (< 70 years old) (P < 0.05). Methylation was less frequently found in grade I-II (18.2%) than in grade III-IV (70.0%) (P < 0.05).</p><p><b>CONCLUSION</b>Methylation of hMSH2 gene in promoter region is related to patients' age and histopathological grade of the esophageal cancer.</p>