| Objectives:The diagnosis and therapy of cancer are still a major biomedical problem currently. The mechanism and molecular pathways remain to be fully elucidated. In these studies, the expresstions of anti-apoptotic molecule BRE, and its binding proteins ANXâ…¡, and TNFR1 were examined in different kinds of tumor tissues and the relationships between these proteins were analyzed. The reaction of the anti-tumor drug lidamycin (LDM) to wild-type-and knockout-cells of a transcriptional activator PML, and the co-localization of PML and muscle protein titin were also analyzed.Methods and results:(1)To examine the expression of BRE, ANXâ…¡and TNFR1 in different liver tissues (total 84 samples), hepatocellular carcinoma (HCC) (56 samples), nasopharygeal carcinoma (NPC) (5 samples), gastric carcinoma (GC)(5 samples), renal cell carcinoma (RCC) (5 samples), overian cancer (OC)(5 samples) and glioma (5 samples) with immunohisto-chemistry (IHC). The expression of BRE in most normal liver tissues (5 samples tissuses) was negative while BRE was overexpressed in most HCC (42 out of 56). But there was no difference among tumors of different WHO classification. In NPC, the expression of BRE was positive (3 out of 5), while it was weakly positive in adjacent cells of the tumor (1 samples). The expression of BRE was positive in 3 out of 5 gastric carcinoma samples. In granulated cell carcinoma and clear cell carcinoma of RCC, BRE expression was high (5 samples). BRE was overexpressed in overian cancer (3 out of 5) and glioma (4 out of 5) too. ANXâ…¡expression was increased in HCC (44 out of 56), while its expression was negative in normal liver tissues (5 samples). ANX II expression was positive in NPC (3 out of 5), while its expression was positive in epithelial tissues adjacent to the tumors (1 samples). ANXâ…¡was down-regulated in GC, its expression was positive in 4 out of 5 samples. It was weakly expressed in RCC and its expression was positive in 4 out of 5 samples too. The expression of ANX-II was positive in 4 out of 5 samples,and the expression was high in clear cell carcinomas (1 sample) of overian cancers. The expression of ANX-â…¡was positive in 4 out of 5 samples in glioma. TNFR1 was also overexpressed in HCC (33 out of 56), and it was weakly positive in NPC (4 samples).The expression of TNFR1 was positive in GC (4 samples), RCC (3 samples) and overian cancer (3 samples).The expression was positive in 4 out of 5 samples in glioma.(2) In determining the co-localization of PML and Titin in Lovo cell with Immunofluorescence staining (IF), it was found that they can co-localize perfectly in the nucleus of cells as nuclear bodies. These data indicate that the interaction of muscle protein titin and the transcriptional activator PML could be to transfer signals from the sarcomeres into the nucleus so as to activate new gene expression for tissue damage and repair. (3) In investigating the reactions of fibroblast cells which are PML++(wild-type) and PML--(knockout) to the anti-tumor drug, LDM, both types of cells were induced to become apoptotic after 24h of treatment, when the concentration of LDM was10("10)mol/L.Conclusions:(1)BRE was strongly expressed in HCC, GC, RCC, overian cancer and gliomas while it wasweakly expressed in NPC. ANXâ…¡was strongly expressed in HCC, overian cancer, glioma while it was weak in NPC, GC, and RCC. TNFR1 was overpressed in HCC, and it was weakly positive in NPC. It was obviously positive in GC, RCC, overian cancer and giloma.(2) PML and Titin co-localized in the nucleus of Lovo cells. (3) Fibroblast cells of PML++and PML-were induced to apoptosis by the anticancer drug LDM but reacted similarly. The high expression of BRE was an approach of the tumor cells to inhibit the apoptotic pathways, which would allow the tumor cells to survive better and to proliferate. Enhanced expression of ANX-â…¡will allow the tumor cells to better infiltrate and metastasize. Increased expression of TNFR1 will enhance the cellular response to the proinflammatory cytokine TNF, which may induce cell growth. The data of the interaction of muscle protein titin and the transcriptional activator PML indicate that this process may involve the transfer of signals from the sarcomeres into the nucleus so as to activate new gene expression for tissue damage and repair. The reaction of anticancer drug LDM with PML-wild-type and-knockout cells may elucidate that its not the unique pathway in the mechanism of LDM's action on normal and cancer cells. |
