Identification of tumor stem-like cells in a mouse myeloma cell line

We used colony formation assay in the soft agar media or the serum-free media, the methods of identifying BrdU-label-retaining cells and the SP cells as well as the tumorigenicity test in BALB/c mice, respectively, to analyze tumor stem like cells in the SP2/0 cell line. The results showed that a few SP2/0 cells were capable of forming colonies in the soft agar media, contained BrdU-label-immortal strand in the SP2/0 cell line. The SP2/0 cells in the serum-free media gained higher tumorigenicity in the BALB/c mice than the SP2/0 cells cultivated in the complete media did. Overall, only a few of the SP2/0 cells were found to possess the characteristics of tumor stem-like cells, such as high proliferative potency, more self-renewal and stronger tumorigenesis, or greater similarity to the tumor stem cells (TSCs) traits. The biology of tumor stem-like cells contributes to the identification of molecular targets important for future tumor therapy.

Novel esters of glaucarubolone as inducers of terminal differentiation of promyelocytic HL-60 cells and inhibitors of 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesion formation in mouse mammary organ culture

In an effort to discover new chemotherapeutic/chemopreventive agents from natural sources, brusatol (1) was found to induce HL-60 cellular differentiation, accompanied by strong antiproliferative and cytotoxic effects. A series of natural and semisynthetic quassinoids (1-48) was designed to effect both antiproliferative and differentiation-inducing properties. Compounds were assessed in vitro using the HL-60 promyelocytic cell model. Changes in activity due to structural modification of the core structure glaucarubolone (24) were consistent with activities reported in other cell systems. However, the following were novel SAR findings: (1) semisynthetic analogues with a hydroxylated ring at the beta-position of the ester side chain at C-15 were able to induce cellular differentiation at concentrations lower than those inducing cell growth arrest, and (2) quassinoids inhibiting DNA synthesis with greater efficacy than reducing cellular viability possessed alkyl substitutions at the alpha-position of the C-15 ester side chain. Analogues from this latter group and brusatol (1) and bruceantin (2) inhibited dimethylbenz(a)anthracene-induced preneoplastic lesion formation in a mouse mammary organ culture. The novel finding of 1 and glaucarubolone analogues as potent inducers of differentiation leads to potential novel applications in the field of cancer.

Effect of immunization in mice with recombinant DNA encoding the hepatitis C virus structural protein

OBJECTIVE

To explore the possibility and the efficacy of immune responses in mice inoculated with recombinant plasmid pCD-HCV1 and to lay a foundation for HCV nucleic acid vaccine development in the future.

METHODS

The gene fragment coding C and E regions of HCV-II (type I b) was inserted into pCD-SR alpha 1 expression vector and formed pCD-HCV1 and then was injected into quadriceps muscles of Balb/c mouse. Serum anti-HCV level of mice was tested by ELISA (A value). Spleen cells proliferation responses to HCV antigens were detected by 3H-TdR incorporation (cpm).

RESULTS

Balb/c mice immunized with recombinant plasmid pCD-HCV1 three or four times can generate specific antibody responses to HCV antigens and the antibody levels gradually ascend to the plateaus and did not have the trend of descending in 18 weeks detected. The serum antibodies in mice immunized by recombinant plasmid pCD-HCV1 were 100 percent positive when the serum were diluted 40 times and the positive rate of antibody still were 16.6 percent positive when the serum were diluted 320 times. Balb/c mice immunized with recombinant plasmid pCD-HCV1 (100 micrograms, 50 micrograms 10 micrograms/mouse three times respectively) can elicit antibody responses to HCV antigens and the antibody levels of three groups were 0.70 +/- 0.07, 0.33 +/- 0.04 and 0.11 +/- 0.09 respectively. Spleen cells of Blab/c mice injected with pCD-HCV1 three times were induced to produce proliferation responses to HCVc + e specific antigens.

CONCLUSIONS

These results demonstrated that constructs expressioning HCV core and envelope proteins can generate anti-HCVc + e specific antibody responses and lymphoproliferation responses in mice, which suggested it to be possible to elicit immune responses to viral epitopes from HCV via DNA immunization with HCV-DNA recombinant and to warrant further investigation as a potential vaccine against HCV infections.

[Experimental study of immunization of mice with hepatitis C virus genetic vaccine constructs]

OBJECTIVE

To inquire into the immune responses to expression protein in mice immunized with genetic vaccine of hepatitis C virus (HCV) and lay a foundation for HCV genetic vaccine development in future.

METHODS

The gene fragments coding C and most E regions of HCV-II type were inserted into pCD-SRalpha(1) of eukaryotic expression vector and formed genetic vaccine constructs of pCD-HCV(1) and then was injected into the quadriceps muscles of Balb/c mice. The serum anti-HCV level of mice was tested by ELISA and peripheral blood mononuclear cell (PBMC) proliferative responses to HCV antigens were detected by (3)H-TdR incorporation method (cpm).

RESULTS

The serum antibody level reached to 0.71 +/- 0.08 - 0.77 +/- 0.06 (A value, the same below) after genetic vaccine pCD-HCV(1) (100 microg/mouse) were inoculated into the mice (n = 12) three or four times while blank vector pCD-SRalpha(1) could not induce the mice (n = 8) to generate antibody response in same way. After the antibody levels in mice (n = 8) immunized by pCD-HCV(1) had ascended to peak value (0.71), there was no trend of descending during the following 18 weeks of detection (0.68 +/- 0.06 - 0.75 +/- 0.07). Specific fragment of HCV cDNA identified by polymerase chain reaction (PCR) from DNA extracted from the muscles of the mice after pCD-HCV(1) had been inoculated three months. PBMC proliferative responses to HCV synthetic peptides CP(9) and gene recombinant antigens C, E(1) in the mice immunized with pCD-HCV(1) were detected and its stimulation indexes (SI) were 4.07 +/- 1.58, 3.88 +/- 0.70 and 3.69 +/- 1.13 respectively and there was a significant difference (P < 0.001) as compared with that of PBMC in mice immunized with pCD-SRalpha(1).

CONCLUSION

These investigations demonstrated that genetic vaccine constructs made of HCV structural region can induce Balb/c mice to generate antibody and PBMC proliferative responses to HCV antigens via DNA immunization.

Gas chromatography/principal component similarity system for detection of E. coli and S. aureus contaminating salmon and hamburger

Coho, Atlantic, Spring, and Sockeye salmon and five commercial samples of hamburger patties were analyzed by processing gas chromatography (GC) data of volatile compounds using the principal component similarity (PCS) technique. PCS scattergrams of the samples inoculated with Escherichia coli and Staphylococcus aureus followed by incubation showed the pattern-shift lines moving away from the data point for uninoculated, unincubated reference samples in different directions with increasing incubation time. When the PCS scattergrams were drawn for samples incubated overnight, the samples inoculated with the two bacterial species and the uninoculated samples appeared as three separated groups. This GC/PCS approach has the potential to ensure quality of samples by discriminating good samples from potentially spoiled samples. The latter may require further microbial assays to identify the bacteria species potentially contaminating foods.

[Clinical analysis of 19 patients with pleural mesothelioma]

OBJECTIVE

To summarize the experience in the diagnosis of pleural mesothelioma.

METHODS

Analysing the clinical data of 19 patients with pleural mesothelioma, including age, history of exposure to asbestos, clinical manifestations, imaging and laboratory examinations and metastases.

RESULTS

None of the 19 patients had history of exposure to asbestos. Eight cases(42.1%) had no obvious thoracodynia, 9 cases(47.4%) had pleural effusion limited to the right chest, and in 2 cases(10.5%) the brachialis plexus was involved, and in 1 case (5.3%) malignant mesothelial cells were detected in the pleural effusion. Pleural thickening or nodules were found in 13 cases on CT and in 9 cases by B ultrasonographic examination.

CONCLUSION

Exposure to asbestos is not the only cause of pleural mesothelioma. Chest pain is not always associated with pleural mesothelioma. CT and B ultrasonography are of good help in the diagnosis of pleural mesothelioma.

A new quassinoid from Castela texana

A new quassinoid, 11-O-trans-p-coumaroyl amarolide (1) was isolated from Castela texana, and the structure was elucidated by spectroscopic analysis. Compound 1 is the first coumaroyl quassinoid derivative to have been isolated from nature. The known compounds amarolide (2), chaparrinone, chaparrin, glaucarubolone, holacanthone, and 15-O-beta-D-glucopyranosyl glaucarubol were also isolated. All isolated compounds were tested for their cytotoxicity and antiprotozoal activities.

[Effect of si jun zi tang on the macrophage cytotoxic activity in mice]

The effect of Si Jun Zi Tang (SJZT) on the activities of peritoneal macrophage (M phi) mediated MTC and ADCC in normal and immunosuppressed mice were examined by isotope releasing assay (51Cr, 125I-UdR). The results showed the SJZT no significantly increased peritoneal M phi-mediated cytotoxic activity (MTC, ADCC) in normal mice. After the injection of immuno-depressive cyclophosphamide (Cy) alone (ip), the cytotoxic activities were decreased, but by treatment with Cy and SJZT, the cytotoxic activities were significantly increased compared with Cy group, the enhancing rates amounted to 74.40% (M phi-MTC) and 121.03% (M phi-ADCC) respectively. It was demonstrated that the SJZT could protest against the effect that the Cy inhibited the activities of MTC and ADCC of peritoneal M phi in mice, but there was no significant effect on normal mice. It indicated that the function of SJZT's immunoregulation was related to the state of immune in body.