Advance in studies on antitumor and immunomodulatory effects of wogonin / 中国中药杂志

Wogonin is a kind of natural flavonoid compound. According to findings in the latest studies, wogonin shows a wide range of antitumor effects, with the characteristics of multi-pathway, multi-link and multi-target, such as promoting tumor cell apoptosis through ROS or Ca(2+)-mediated signal paths, enhancing tumor cytotoxicity by TNF-α and TRAIL, blocking tumor cell cycle, inhibiting tumor angiogenesis and resisting cancer synergistically with chemotherapeutic drugs. Moreover, Wogonin could enhance body immune function by enhancing immune cell infiltration, regulating the immune cell phenotype and promoting relevant cytokine secretion. In this paper, the authors summarized the advance in studies on wogonin's antitumor and immunomodulatory effects.

Association of MICA gene polymorphism and serum soluble MICA level with colorectal cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate whether the major histocompatibility complex class I chain-related gene A gene (MICA) polymorphism and serum soluble MICA level were associated with the occurrence and development of colorectal cancer.</p><p><b>METHODS</b>DNA samples from 117 colorectal cancer patients and 113 healthy individuals from Yangzhou in Jiangsu province were genotyped by using the polymerase chain reaction (PCR) and sequence-specific primer (SSP) method and PCR based sequencing. In addition, polymorphism at position 129 was also analyzed by PCR-SSP. Serum levels of soluble MICA were measured by a sandwich ELISA method.</p><p><b>RESULTS</b>Neither the extracellular nor the transmembrane region polymorphisms of MICA gene were associated with the occurrence and the different stages of colorectal cancer. In contrast, the frequency of the methionine residue at position 129 was significantly decreased in the patient group. Soluble MICA levels in sera were increased in the late stages of colorectal cancer.</p><p><b>CONCLUSION</b>Although there was no genetic susceptibility attributed to MICA gene polymorphism with regard to development of colorectal cancer, serum levels of soluble MICA may be a diagnostic marker of advanced stages.</p>

Correlation of Helicobacter pylori infection with the expression of COX-2 and EGFR and VEGF in human gastric carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation of Helicobactor pylori (Hp) infection with the expression of COX-2, EGFR and VEGF in human gastric carcinoma.</p><p><b>METHODS</b>The expression of COX-2, EGFR and VEGF was detected by immunohistochemistry in samples of 61 gastric cancers and 20 cancer-adjacent tissues. Western blotting was performed in samples of 10 gastric cancers and corresponding cancer-adjacent tissues. Hp infection was detected in 47 patients by fast urea enzyme test and (13)C breath test.</p><p><b>RESULTS</b>The results of immunohistochemistry showed that the positive expressions of COX-2, EGFR and VEGF in gastric carcinoma were 59.02%, 36.07% and 60.66%, respectively, significantly higher than that in the normal mucosa (25.00%, 0 and 30.00%, respectively). There was a positive correlation between the expression of COX-2, EGFR and VEGF and gastric carcinoma. The expression of COX-2 and EGFR was 75.76% and 45.45% in the gastric carcinomas with Hp infection, significantly higher than that in those without (28.57% and 14.29%). The protein expression of COX-2, EGFR and VEGF detected by Western blot in gastric carcinomas was also significantly higher than that in normal mucosa.</p><p><b>CONCLUSION</b>COX-2, EGFR and VEGF are overexpressed in gastric carcinoma, and there is a positive correlation among them. Hp infection may upregulate the expression of COX-2 and EGFR in gastric cancer tissues.</p>

Immune protective mechanisms of gene vaccines with co-expressing bcr-abl fusion gene fragment and mouse IL-7 gene / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the influence of mIL-7 on the immune response induced by vaccine of bcr-abl fusion gene fragment in mouse.</p><p><b>METHODS</b>BALB/c mice were immunized by i. m. injection of pVbcr-abl/mIL-7 and pVbcr-abl, respectively. The specific antibody to p210bcr-abl protein was assayed by ELISA. The CTL activity of spleen cells from the immunized mice was assessed with LDH release test.</p><p><b>RESULTS</b>The pVbcr-abl/mIL-7 and pVbcr-abl-immunized BALB/c mice elicited higher specific antibodies to p210bcr-abl protein. The specific antibody level of former group was higher than that in latter group, but the difference was statistically not significant. The spleen cells from the immunized mice showed more effective CTL activity than that from control group. The cytotoxic activity of spleen CTLs induced by pVbcr-abl/mIL-7 immunized mice exceeded that of pVbcr-ab-immunized mice.</p><p><b>CONCLUSION</b>The mIL-7 may influence the growth and differentiation of T cells, promote some T cells migrating into tumor tissue and up-regulate the specific cellular immune response. The results of this study provided an useful experimental basis for preclinical research on gene vaccine for chronic myeloid leukemia.</p>

Recombinant eukaryotic expression plasmid of bcr-abl gene fragment induces specific immune response in mice / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the specific immune response induced by a recombinant eukaryotic expression plasmid encoding bcr-abl fusion gene fragment so as to explore new immunotherapy in mouse.</p><p><b>METHODS</b>A recombinant eukaryotic vector pVbcr-abl expression cDNA fragment of bcr-abl fusion gene was constructed and used to immunize BALB/c mice. Serum level of bcr-abl specific antibody was detected by enzyme-linked immunosorbent assay (ELISA). Twenty days later the immunized mice were subcutaneously inoculated SP2/0/bcr-abl cells. The survival time, tumor growth time and lymphocytic infiltration were observed. T cells infiltration into tumor tissue was analyzed by immunohistochemistry. Changes of T cell subset in the spleen of mice was analyzed by fluorescent-activated cell sorting (FACS) and the cytotoxicity T lymphocyte (CTL) activity in spleen by lactate dehydrogenase (LDH)-release assay.</p><p><b>RESULTS</b>The eukaryotic expression vector pVbcr-abl was constructed successfully, and highly expressed the cDNA fragment of bcr-abl fusion gene. The BALB/c mice immunized with the vector could generate the specific antibody and CTL, resulting in a specific immunoprotection. There were dramatic differences in the tumor-forming time, tumor ulcer appearing time and tumor-growing speed between the immunized and the control groups. The mice had longer survival time in the immunized group than in the control group. There were a large amount of CD3(+) T cells infiltration in tumor tissue of the immunized mice. The spleen cells from the immunized mice had higher CTL activity with a alteration of T cell subset, the CD4(+)/CD8(+) ratio being 1.54 +/- 0.29, higher than that of control group (1.18 +/- 0.30).</p><p><b>CONCLUSION</b>The recombinant eukaryotic expression plasmid pVbcr-abl can induce in vivo not only the generation of specific antibody, but also high level of specific CTL activity, resulting in killing the SP2/0/bcr-abl tumor cells directly and inhibiting the tumor growth.</p>

Influences of bcr-abl gene vaccine on inoculated SP2/0/bcr-abl tumor cells in mice / 中国实验血液学杂志

To study the influence of vaccine of bcr-abl fusion gene fragment on inoculated SP2/0/bcr-abl tumor cells in mice, BALB/c mice were immunized with pVbcr-abl, pVbcr-abl/mIL7 plasmids, respectively, then SP2/0/bcr-abl cells expressing the fragment of bcr-abl fusion gene were inoculated subcutaneously into the groin of BALB/c mice in order to observe the effect of vaccine on growth of inoculated SP2/0/bcr-abl tumor cells. The results showed that there were distinct differences on the time of tumor growth, the time of tumor ulceration, tumor volume and survival time of mice bearing tumor between two immunized groups and two control groups (blank and vacant plasmid groups). The mice immunized with pVbcr-abl/mIL7 lived longer as compared to mice immunized with pVbcr-abl. The tissue of inoculated tumor was more compact, tumor organ was larger, tumor form was irregular in 2 control groups, while the tissue of inoculated tumor was looser, tumor volume was smaller, and with mass inflammatory infiltration in two immunized groups. Moreover, the metastatic tumor cells were found in the livers of control groups, but not observed in two immunized groups. It is concluded that the protection occurred in immunized mice which inhibited the growth of SP2/0/bcr-abl tumor cell in vivo.

Establishment of mouse SP2/0 cell line stably expressing bcr-abl fusion gene fragment / 中国实验血液学杂志

To establish SP2/0 cell line H-2(d) stably expressing bcr-abl fusion gene fragment, the bcr-abl fusion gene was subcloned into retroviral vector pLXSN from pGEMbcr-abl. The recombinant retroviral vector pLXSNbcr-abl was transfected into PT67 packaging cells with the help of lipofectamine. The positive clones were selected out and cultured after G418 selection. Then viral supernatant was collected to determine viral titer, the viral titer was 2 x 10(7) CFU/ml. The SP2/0 cells were infected with the collected viral supernatant. The results showed that after G418 selection, the bcr-abl fusion gene was integrated into the chromosome of SP2/0 cells infected stably, with recombinant retrovirus and expressed in SP2/0 cells confirmed by PCR and RT-PCR respectively. In conclusion, the mouse tumor cell lines expressing the bcr-abl fusion protein were successfully established and would be used as a experimental cell model for anti-CML immunotherapy.